HDFS-3920. Merging change 1403173 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1403174 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -58,6 +58,9 @@ Release 2.0.3-alpha - Unreleased
 
     HADOOP-8925. Remove the packaging. (eli)
 
+    HADOOP-8985. Add namespace declarations in .proto files for languages 
+    other than java. (Binglin Chan via suresh)
+
   OPTIMIZATIONS
 
     HADOOP-8866. SampleQuantiles#query is O(N^2) instead of O(N). (Andrew Wang

hadoop-common-project/hadoop-common/src/main/proto/HAServiceProtocol.proto

@@ -20,6 +20,7 @@ option java_package = "org.apache.hadoop.ha.proto";
 option java_outer_classname = "HAServiceProtocolProtos";
 option java_generic_services = true;
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 enum HAServiceStateProto {
   INITIALIZING = 0;

hadoop-common-project/hadoop-common/src/main/proto/IpcConnectionContext.proto

@@ -18,6 +18,7 @@
 option java_package = "org.apache.hadoop.ipc.protobuf";
 option java_outer_classname = "IpcConnectionContextProtos";
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 /**
  * Spec for UserInformationProto is specified in ProtoUtil#makeIpcConnectionContext

hadoop-common-project/hadoop-common/src/main/proto/ProtocolInfo.proto

@@ -20,6 +20,7 @@ option java_package = "org.apache.hadoop.ipc.protobuf";
 option java_outer_classname = "ProtocolInfoProtos";
 option java_generic_services = true;
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 /**
  * Request to get protocol versions for all supported rpc kinds.

hadoop-common-project/hadoop-common/src/main/proto/RpcPayloadHeader.proto

@@ -18,6 +18,7 @@
 option java_package = "org.apache.hadoop.ipc.protobuf";
 option java_outer_classname = "RpcPayloadHeaderProtos";
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 /**
  * This is the rpc payload header. It is sent with every rpc call.

hadoop-common-project/hadoop-common/src/main/proto/ZKFCProtocol.proto

@@ -20,6 +20,7 @@ option java_package = "org.apache.hadoop.ha.proto";
 option java_outer_classname = "ZKFCProtocolProtos";
 option java_generic_services = true;
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 message CedeActiveRequestProto {
   required uint32 millisToCede = 1;

hadoop-common-project/hadoop-common/src/main/proto/hadoop_rpc.proto

@@ -23,6 +23,7 @@
 option java_package = "org.apache.hadoop.ipc.protobuf";
 option java_outer_classname = "HadoopRpcProtos";
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 /**
  * This message is used for Protobuf Rpc Engine.

hadoop-common-project/hadoop-common/src/test/proto/test.proto

@@ -19,6 +19,7 @@
 option java_package = "org.apache.hadoop.ipc.protobuf";
 option java_outer_classname = "TestProtos";
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 message EmptyRequestProto {
 }

hadoop-common-project/hadoop-common/src/test/proto/test_rpc_service.proto

@@ -19,6 +19,7 @@ option java_package = "org.apache.hadoop.ipc.protobuf";
 option java_outer_classname = "TestRpcServiceProtos";
 option java_generic_services = true;
 option java_generate_equals_and_hash = true;
+package hadoop.common;
 
 import "test.proto";
 

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -424,6 +424,9 @@ Release 2.0.2-alpha - 2012-09-07
     to avoid partial edits case disk out of space. (Colin McCabe via todd)
 
     HDFS-3910. DFSTestUtil#waitReplication should timeout. (eli)
+    
+    HDFS-3920. libwebdhfs string processing and using strerror consistently
+    to handle all errors. (Jing Zhao via suresh)
 
   OPTIMIZATIONS
 

hadoop-hdfs-project/hadoop-hdfs/src/contrib/libwebhdfs/src/hdfs_http_client.c

@@ -15,28 +15,43 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 #include <stdlib.h>
 #include <string.h>
 #include <curl/curl.h>
-#include <pthread.h>
+
 #include "hdfs_http_client.h"
 
 static pthread_mutex_t curlInitMutex = PTHREAD_MUTEX_INITIALIZER;
 static volatile int curlGlobalInited = 0;
 
-ResponseBuffer initResponseBuffer() {
-    ResponseBuffer info = (ResponseBuffer) calloc(1, sizeof(ResponseBufferInternal));
+const char *hdfs_strerror(int errnoval)
+{
+    const char *msg = NULL;
+    if (errnoval < 0 || errnoval >= sys_nerr) {
+        msg = "Invalid Error Code";
+    } else if (sys_errlist == NULL) {
+        msg = "Unknown Error";
+    } else {
+        msg = sys_errlist[errnoval];
+    }
+    return msg;
+}
+
+int initResponseBuffer(struct ResponseBuffer **buffer)
+{
+    struct ResponseBuffer *info = NULL;
+    int ret = 0;
+    info = calloc(1, sizeof(struct ResponseBuffer));
     if (!info) {
-        fprintf(stderr, "Cannot allocate memory for responseInfo\n");
-        return NULL;
+        ret = ENOMEM;
     }
-    info->remaining = 0;
-    info->offset = 0;
-    info->content = NULL;
-    return info;
+    *buffer = info;
+    return ret;
 }
 
-void freeResponseBuffer(ResponseBuffer buffer) {
+void freeResponseBuffer(struct ResponseBuffer *buffer)
+{
     if (buffer) {
         if (buffer->content) {
             free(buffer->content);
@@ -46,8 +61,9 @@ void freeResponseBuffer(ResponseBuffer buffer) {
     }
 }
 
-void freeResponse(Response resp)  {
-    if(resp) {
+void freeResponse(struct Response *resp)
+{
+    if (resp) {
         freeResponseBuffer(resp->body);
         freeResponseBuffer(resp->header);
         free(resp);
@@ -55,21 +71,30 @@ void freeResponse(Response resp)  {
     }
 }
 
-/* Callback for allocating local buffer and reading data to local buffer */
-static size_t writefunc(void *ptr, size_t size, size_t nmemb, ResponseBuffer rbuffer) {
+/** 
+ * Callback used by libcurl for allocating local buffer and 
+ * reading data to local buffer
+ */
+static size_t writefunc(void *ptr, size_t size,
+                        size_t nmemb, struct ResponseBuffer *rbuffer)
+{
+    void *temp = NULL;
     if (size * nmemb < 1) {
         return 0;
     }
     if (!rbuffer) {
-        fprintf(stderr, "In writefunc, ResponseBuffer is NULL.\n");
-        return -1;
+        fprintf(stderr,
+                "ERROR: ResponseBuffer is NULL for the callback writefunc.\n");
+        return 0;
     }
     
     if (rbuffer->remaining < size * nmemb) {
-        rbuffer->content = realloc(rbuffer->content, rbuffer->offset + size * nmemb + 1);
-        if (rbuffer->content == NULL) {
-            return -1;
+        temp = realloc(rbuffer->content, rbuffer->offset + size * nmemb + 1);
+        if (temp == NULL) {
+            fprintf(stderr, "ERROR: fail to realloc in callback writefunc.\n");
+            return 0;
         }
+        rbuffer->content = temp;
         rbuffer->remaining = size * nmemb;
     }
     memcpy(rbuffer->content + rbuffer->offset, ptr, size * nmemb);
@@ -80,67 +105,84 @@ static size_t writefunc(void *ptr, size_t size, size_t nmemb, ResponseBuffer rbu
 }
 
 /**
- * Callback for reading data to buffer provided by user, 
+ * Callback used by libcurl for reading data into buffer provided by user,
  * thus no need to reallocate buffer.
  */
-static size_t writefunc_withbuffer(void *ptr, size_t size, size_t nmemb, ResponseBuffer rbuffer) {
+static size_t writeFuncWithUserBuffer(void *ptr, size_t size,
+                                   size_t nmemb, struct ResponseBuffer *rbuffer)
+{
+    size_t toCopy = 0;
     if (size * nmemb < 1) {
         return 0;
     }
     if (!rbuffer || !rbuffer->content) {
-        fprintf(stderr, "In writefunc_withbuffer, the buffer provided by user is NULL.\n");
+        fprintf(stderr,
+                "ERROR: buffer to read is NULL for the "
+                "callback writeFuncWithUserBuffer.\n");
         return 0;
     }
     
-    size_t toCopy = rbuffer->remaining < (size * nmemb) ? rbuffer->remaining : (size * nmemb);
+    toCopy = rbuffer->remaining < (size * nmemb) ?
+                            rbuffer->remaining : (size * nmemb);
     memcpy(rbuffer->content + rbuffer->offset, ptr, toCopy);
     rbuffer->offset += toCopy;
     rbuffer->remaining -= toCopy;
     return toCopy;
 }
 
-//callback for writing data to remote peer
-static size_t readfunc(void *ptr, size_t size, size_t nmemb, void *stream) {
+/**
+ * Callback used by libcurl for writing data to remote peer
+ */
+static size_t readfunc(void *ptr, size_t size, size_t nmemb, void *stream)
+{
+    struct webhdfsBuffer *wbuffer = NULL;
     if (size * nmemb < 1) {
-        fprintf(stderr, "In readfunc callback: size * nmemb == %ld\n", size * nmemb);
         return 0;
     }
-    webhdfsBuffer *wbuffer = (webhdfsBuffer *) stream;
     
+    wbuffer = stream;
     pthread_mutex_lock(&wbuffer->writeMutex);
     while (wbuffer->remaining == 0) {
         /*
-         * the current remainning bytes to write is 0,
-         * check whether need to finish the transfer
+         * The current remainning bytes to write is 0,
+         * check closeFlag to see whether need to finish the transfer.
          * if yes, return 0; else, wait
          */
-        if (wbuffer->closeFlag) {
-            //we can close the transfer now
+        if (wbuffer->closeFlag) { // We can close the transfer now
+            //For debug
             fprintf(stderr, "CloseFlag is set, ready to close the transfer\n");
             pthread_mutex_unlock(&wbuffer->writeMutex);
             return 0;
         } else {
-            // len == 0 indicates that user's buffer has been transferred
+            // remaining == 0 but closeFlag is not set
+            // indicates that user's buffer has been transferred
             pthread_cond_signal(&wbuffer->transfer_finish);
-            pthread_cond_wait(&wbuffer->newwrite_or_close, &wbuffer->writeMutex);
+            pthread_cond_wait(&wbuffer->newwrite_or_close,
+                                    &wbuffer->writeMutex);
         }
     }
     
-    if(wbuffer->remaining > 0 && !wbuffer->closeFlag) {
-        size_t copySize = wbuffer->remaining < size * nmemb ? wbuffer->remaining : size * nmemb;
+    if (wbuffer->remaining > 0 && !wbuffer->closeFlag) {
+        size_t copySize = wbuffer->remaining < size * nmemb ?
+                                wbuffer->remaining : size * nmemb;
         memcpy(ptr, wbuffer->wbuffer + wbuffer->offset, copySize);
         wbuffer->offset += copySize;
         wbuffer->remaining -= copySize;
         pthread_mutex_unlock(&wbuffer->writeMutex);
         return copySize;
     } else {
-        fprintf(stderr, "Webhdfs buffer is %ld, it should be a positive value!\n", wbuffer->remaining);
+        fprintf(stderr, "ERROR: webhdfsBuffer's remaining is %ld, "
+                "it should be a positive value!\n", wbuffer->remaining);
         pthread_mutex_unlock(&wbuffer->writeMutex);
         return 0;
     }
 }
 
-static void initCurlGlobal() {
+/**
+ * Initialize the global libcurl environment
+ */
+static void initCurlGlobal()
+{
     if (!curlGlobalInited) {
         pthread_mutex_lock(&curlInitMutex);
         if (!curlGlobalInited) {
@@ -151,202 +193,297 @@ static void initCurlGlobal() {
     }
 }
 
-static Response launchCmd(char *url, enum HttpHeader method, enum Redirect followloc) {
-    CURL *curl;
-    CURLcode res;
-    Response resp;
+/**
+ * Launch simple commands (commands without file I/O) and return response
+ *
+ * @param url       Target URL
+ * @param method    HTTP method (GET/PUT/POST)
+ * @param followloc Whether or not need to set CURLOPT_FOLLOWLOCATION
+ * @param response  Response from remote service
+ * @return 0 for success and non-zero value to indicate error
+ */
+static int launchCmd(const char *url, enum HttpHeader method,
+                     enum Redirect followloc, struct Response **response)
+{
+    CURL *curl = NULL;
+    CURLcode curlCode;
+    int ret = 0;
+    struct Response *resp = NULL;
     
-    resp = (Response) calloc(1, sizeof(*resp));
+    resp = calloc(1, sizeof(struct Response));
     if (!resp) {
-        return NULL;
+        return ENOMEM;
+    }
+    ret = initResponseBuffer(&(resp->body));
+    if (ret) {
+        goto done;
+    }
+    ret = initResponseBuffer(&(resp->header));
+    if (ret) {
+        goto done;
     }
-    resp->body = initResponseBuffer();
-    resp->header = initResponseBuffer();
     initCurlGlobal();
-    curl = curl_easy_init();                     /* get a curl handle */
-    if(curl) {
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
-        curl_easy_setopt(curl, CURLOPT_WRITEDATA, resp->body);
-        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, writefunc);
-        curl_easy_setopt(curl, CURLOPT_WRITEHEADER, resp->header);
-        curl_easy_setopt(curl, CURLOPT_URL, url);       /* specify target URL */
-        switch(method) {
-            case GET:
-                break;
-            case PUT:
-                curl_easy_setopt(curl,CURLOPT_CUSTOMREQUEST,"PUT");
-                break;
-            case POST:
-                curl_easy_setopt(curl,CURLOPT_CUSTOMREQUEST,"POST");
-                break;
-            case DELETE:
-                curl_easy_setopt(curl,CURLOPT_CUSTOMREQUEST,"DELETE");
-                break;
-            default:
-                fprintf(stderr, "\nHTTP method not defined\n");
-                exit(EXIT_FAILURE);
-        }
-        if(followloc == YES) {
-            curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
-        }
-        
-        res = curl_easy_perform(curl);                 /* Now run the curl handler */
-        if(res != CURLE_OK) {
-            fprintf(stderr, "preform the URL %s failed\n", url);
-            return NULL;
-        }
+    curl = curl_easy_init();
+    if (!curl) {
+        ret = ENOMEM;       // curl_easy_init does not return error code,
+                            // and most of its errors are caused by malloc()
+        fprintf(stderr, "ERROR in curl_easy_init.\n");
+        goto done;
+    }
+    /* Set callback function for reading data from remote service */
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, resp->body);
+    curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEHEADER, resp->header);
+    curl_easy_setopt(curl, CURLOPT_URL, url);
+    switch(method) {
+        case GET:
+            break;
+        case PUT:
+            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "PUT");
+            break;
+        case POST:
+            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
+            break;
+        case DELETE:
+            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "DELETE");
+            break;
+        default:
+            ret = EINVAL;
+            fprintf(stderr, "ERROR: Invalid HTTP method\n");
+            goto done;
+    }
+    if (followloc == YES) {
+        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
+    }
+    /* Now run the curl handler */
+    curlCode = curl_easy_perform(curl);
+    if (curlCode != CURLE_OK) {
+        ret = EIO;
+        fprintf(stderr, "ERROR: preform the URL %s failed, <%d>: %s\n",
+                url, curlCode, curl_easy_strerror(curlCode));
+    }
+done:
+    if (curl != NULL) {
         curl_easy_cleanup(curl);
     }
-    return resp;
+    if (ret) {
+        free(resp);
+        resp = NULL;
+    }
+    *response = resp;
+    return ret;
 }
 
-static Response launchRead_internal(char *url, enum HttpHeader method, enum Redirect followloc, Response resp) {
+/**
+ * Launch the read request. The request is sent to the NameNode and then 
+ * redirected to corresponding DataNode
+ *
+ * @param url   The URL for the read request
+ * @param resp  The response containing the buffer provided by user
+ * @return 0 for success and non-zero value to indicate error
+ */
+static int launchReadInternal(const char *url, struct Response* resp)
+{
+    CURL *curl;
+    CURLcode curlCode;
+    int ret = 0;
+    
     if (!resp || !resp->body || !resp->body->content) {
-        fprintf(stderr, "The user provided buffer should not be NULL!\n");
-        return NULL;
+        fprintf(stderr,
+                "ERROR: invalid user-provided buffer!\n");
+        return EINVAL;
     }
     
-    CURL *curl;
-    CURLcode res;
     initCurlGlobal();
-    curl = curl_easy_init();                     /* get a curl handle */
-    if(curl) {
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc_withbuffer);
-        curl_easy_setopt(curl, CURLOPT_WRITEDATA, resp->body);
-        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, writefunc);
-        curl_easy_setopt(curl, CURLOPT_WRITEHEADER, resp->header);
-        curl_easy_setopt(curl, CURLOPT_URL, url);       /* specify target URL */
-        if(followloc == YES) {
-            curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
-        }
-        
-        res = curl_easy_perform(curl);                 /* Now run the curl handler */
-        if(res != CURLE_OK && res != CURLE_PARTIAL_FILE) {
-            fprintf(stderr, "preform the URL %s failed\n", url);
-            return NULL;
-        }
-        curl_easy_cleanup(curl);
+    /* get a curl handle */
+    curl = curl_easy_init();
+    if (!curl) {
+        fprintf(stderr, "ERROR in curl_easy_init.\n");
+        return ENOMEM;
     }
-    return resp;
-
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeFuncWithUserBuffer);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, resp->body);
+    curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEHEADER, resp->header);
+    curl_easy_setopt(curl, CURLOPT_URL, url);
+    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
+    
+    curlCode = curl_easy_perform(curl);
+    if (curlCode != CURLE_OK && curlCode != CURLE_PARTIAL_FILE) {
+        ret = EIO;
+        fprintf(stderr, "ERROR: preform the URL %s failed, <%d>: %s\n",
+                url, curlCode, curl_easy_strerror(curlCode));
+    }
+    
+    curl_easy_cleanup(curl);
+    return ret;
 }
 
-static Response launchWrite(const char *url, enum HttpHeader method, webhdfsBuffer *uploadBuffer) {
+/**
+ * The function does the write operation by connecting to a DataNode. 
+ * The function keeps the connection with the DataNode until 
+ * the closeFlag is set. Whenever the current data has been sent out, 
+ * the function blocks waiting for further input from user or close.
+ *
+ * @param url           URL of the remote DataNode
+ * @param method        PUT for create and POST for append
+ * @param uploadBuffer  Buffer storing user's data to write
+ * @param response      Response from remote service
+ * @return 0 for success and non-zero value to indicate error
+ */
+static int launchWrite(const char *url, enum HttpHeader method,
+                       struct webhdfsBuffer *uploadBuffer,
+                       struct Response **response)
+{
+    CURLcode curlCode;
+    struct Response* resp = NULL;
+    struct curl_slist *chunk = NULL;
+    CURL *curl = NULL;
+    int ret = 0;
+    
     if (!uploadBuffer) {
-        fprintf(stderr, "upload buffer is NULL!\n");
-        errno = EINVAL;
-        return NULL;
+        fprintf(stderr, "ERROR: upload buffer is NULL!\n");
+        return EINVAL;
     }
+    
     initCurlGlobal();
-    CURLcode res;
-    Response response = (Response) calloc(1, sizeof(*response));
-    if (!response) {
-        fprintf(stderr, "failed to allocate memory for response\n");
-        return NULL;
-    }
-    response->body = initResponseBuffer();
-    response->header = initResponseBuffer();
+    resp = calloc(1, sizeof(struct Response));
+    if (!resp) {
+        return ENOMEM;
+    }
+    ret = initResponseBuffer(&(resp->body));
+    if (ret) {
+        goto done;
+    }
+    ret = initResponseBuffer(&(resp->header));
+    if (ret) {
+        goto done;
+    }
     
-    //connect to the datanode in order to create the lease in the namenode
-    CURL *curl = curl_easy_init();
+    // Connect to the datanode in order to create the lease in the namenode
+    curl = curl_easy_init();
     if (!curl) {
-        fprintf(stderr, "Failed to initialize the curl handle.\n");
-        return NULL;
+        fprintf(stderr, "ERROR: failed to initialize the curl handle.\n");
+        return ENOMEM;
     }
     curl_easy_setopt(curl, CURLOPT_URL, url);
     
-    if(curl) {
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
-        curl_easy_setopt(curl, CURLOPT_WRITEDATA, response->body);
-        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, writefunc);
-        curl_easy_setopt(curl, CURLOPT_WRITEHEADER, response->header);
-        curl_easy_setopt(curl, CURLOPT_READFUNCTION, readfunc);
-        curl_easy_setopt(curl, CURLOPT_READDATA, uploadBuffer);
-        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
-        curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
-        
-        struct curl_slist *chunk = NULL;
-        chunk = curl_slist_append(chunk, "Transfer-Encoding: chunked");
-        res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
-        chunk = curl_slist_append(chunk, "Expect:");
-        res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
-        
-        switch(method) {
-            case GET:
-                break;
-            case PUT:
-                curl_easy_setopt(curl,CURLOPT_CUSTOMREQUEST,"PUT");
-                break;
-            case POST:
-                curl_easy_setopt(curl,CURLOPT_CUSTOMREQUEST,"POST");
-                break;
-            case DELETE:
-                curl_easy_setopt(curl,CURLOPT_CUSTOMREQUEST,"DELETE");
-                break;
-            default:
-                fprintf(stderr, "\nHTTP method not defined\n");
-                exit(EXIT_FAILURE);
-        }
-        res = curl_easy_perform(curl);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, resp->body);
+    curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, writefunc);
+    curl_easy_setopt(curl, CURLOPT_WRITEHEADER, resp->header);
+    curl_easy_setopt(curl, CURLOPT_READFUNCTION, readfunc);
+    curl_easy_setopt(curl, CURLOPT_READDATA, uploadBuffer);
+    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
+    
+    chunk = curl_slist_append(chunk, "Transfer-Encoding: chunked");
+    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
+    chunk = curl_slist_append(chunk, "Expect:");
+    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
+    
+    switch(method) {
+        case PUT:
+            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "PUT");
+            break;
+        case POST:
+            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
+            break;
+        default:
+            ret = EINVAL;
+            fprintf(stderr, "ERROR: Invalid HTTP method\n");
+            goto done;
+    }
+    curlCode = curl_easy_perform(curl);
+    if (curlCode != CURLE_OK) {
+        ret = EIO;
+        fprintf(stderr, "ERROR: preform the URL %s failed, <%d>: %s\n",
+                url, curlCode, curl_easy_strerror(curlCode));
+    }
+    
+done:
+    if (chunk != NULL) {
         curl_slist_free_all(chunk);
+    }
+    if (curl != NULL) {
         curl_easy_cleanup(curl);
     }
-    
-    return response;
+    if (ret) {
+        free(resp);
+        resp = NULL;
+    }
+    *response = resp;
+    return ret;
 }
 
-Response launchMKDIR(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchMKDIR(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }
 
-Response launchRENAME(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchRENAME(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }
 
-Response launchGFS(char *url) {
-    return launchCmd(url, GET, NO);
+int launchGFS(const char *url, struct Response **resp)
+{
+    return launchCmd(url, GET, NO, resp);
 }
 
-Response launchLS(char *url) {
-    return launchCmd(url, GET, NO);
+int launchLS(const char *url, struct Response **resp)
+{
+    return launchCmd(url, GET, NO, resp);
 }
 
-Response launchCHMOD(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchCHMOD(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }
 
-Response launchCHOWN(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchCHOWN(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }
 
-Response launchDELETE(char *url) {
-    return launchCmd(url, DELETE, NO);
+int launchDELETE(const char *url, struct Response **resp)
+{
+    return launchCmd(url, DELETE, NO, resp);
 }
 
-Response launchOPEN(char *url, Response resp) {
-    return launchRead_internal(url, GET, YES, resp);
+int launchOPEN(const char *url, struct Response* resp)
+{
+    return launchReadInternal(url, resp);
 }
 
-Response launchUTIMES(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchUTIMES(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }
 
-Response launchNnWRITE(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchNnWRITE(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }
 
-Response launchNnAPPEND(char *url) {
-    return launchCmd(url, POST, NO);
+int launchNnAPPEND(const char *url, struct Response **resp)
+{
+    return launchCmd(url, POST, NO, resp);
 }
 
-Response launchDnWRITE(const char *url, webhdfsBuffer *buffer) {
-    return launchWrite(url, PUT, buffer);
+int launchDnWRITE(const char *url, struct webhdfsBuffer *buffer,
+                               struct Response **resp)
+{
+    return launchWrite(url, PUT, buffer, resp);
 }
 
-Response launchDnAPPEND(const char *url, webhdfsBuffer *buffer) {
-    return launchWrite(url, POST, buffer);
+int launchDnAPPEND(const char *url, struct webhdfsBuffer *buffer,
+                                struct Response **resp)
+{
+    return launchWrite(url, POST, buffer, resp);
 }
 
-Response launchSETREPLICATION(char *url) {
-    return launchCmd(url, PUT, NO);
+int launchSETREPLICATION(const char *url, struct Response **resp)
+{
+    return launchCmd(url, PUT, NO, resp);
 }

hadoop-hdfs-project/hadoop-hdfs/src/contrib/libwebhdfs/src/hdfs_http_client.h

@@ -26,6 +26,7 @@
 #include <pthread.h> /* for pthread_t */
 #include <unistd.h> /* for size_t */
 
+/** enum indicating the type of hdfs stream */
 enum hdfsStreamType
 {
     UNINITIALIZED = 0,
@@ -36,28 +37,39 @@ enum hdfsStreamType
 /**
  * webhdfsBuffer - used for hold the data for read/write from/to http connection
  */
-typedef struct {
-    const char *wbuffer;  // The user's buffer for uploading
-    size_t remaining;     // Length of content
-    size_t offset;        // offset for reading
-    int openFlag;         // Check whether the hdfsOpenFile has been called before
-    int closeFlag;        // Whether to close the http connection for writing
-    pthread_mutex_t writeMutex; // Synchronization between the curl and hdfsWrite threads
-    pthread_cond_t newwrite_or_close; // Transferring thread waits for this condition
-                                      // when there is no more content for transferring in the buffer
-    pthread_cond_t transfer_finish; // Condition used to indicate finishing transferring (one buffer)
-} webhdfsBuffer;
+struct webhdfsBuffer {
+    const char *wbuffer;  /* The user's buffer for uploading */
+    size_t remaining;     /* Length of content */
+    size_t offset;        /* offset for reading */
+    /* Check whether the hdfsOpenFile has been called before */
+    int openFlag;
+    /* Whether to close the http connection for writing */
+    int closeFlag;
+    /* Synchronization between the curl and hdfsWrite threads */
+    pthread_mutex_t writeMutex;
+    /* 
+     * Transferring thread waits for this condition
+     * when there is no more content for transferring in the buffer
+     */
+    pthread_cond_t newwrite_or_close;
+    /* Condition used to indicate finishing transferring (one buffer) */
+    pthread_cond_t transfer_finish;
+};
 
+/** File handle for webhdfs */
 struct webhdfsFileHandle {
-    char *absPath;
-    int bufferSize;
-    short replication;
-    tSize blockSize;
-    char *datanode;
-    webhdfsBuffer *uploadBuffer;
+    char *absPath;        /* Absolute path of file */
+    int bufferSize;       /* Size of buffer */
+    short replication;    /* Number of replication */
+    tSize blockSize;      /* Block size */
+    char *datanode;       /* URL of the DataNode */
+    /* webhdfsBuffer handle used to store the upload data */
+    struct webhdfsBuffer *uploadBuffer;
+    /* The thread used for data transferring */
     pthread_t connThread;
 };
 
+/** Type of http header */
 enum HttpHeader {
     GET,
     PUT,
@@ -65,44 +77,218 @@ enum HttpHeader {
     DELETE
 };
 
+/** Whether to redirect */
 enum Redirect {
     YES,
     NO
 };
 
-typedef struct {
+/** Buffer used for holding response */
+struct ResponseBuffer {
     char *content;
     size_t remaining;
     size_t offset;
-} ResponseBufferInternal;
-typedef ResponseBufferInternal *ResponseBuffer;
+};
 
 /**
  * The response got through webhdfs
  */
-typedef struct {
-    ResponseBuffer body;
-    ResponseBuffer header;
-}* Response;
-
-ResponseBuffer initResponseBuffer();
-void freeResponseBuffer(ResponseBuffer buffer);
-void freeResponse(Response resp);
-
-Response launchMKDIR(char *url);
-Response launchRENAME(char *url);
-Response launchCHMOD(char *url);
-Response launchGFS(char *url);
-Response launchLS(char *url);
-Response launchDELETE(char *url);
-Response launchCHOWN(char *url);
-Response launchOPEN(char *url, Response resp);
-Response launchUTIMES(char *url);
-Response launchNnWRITE(char *url);
-
-Response launchDnWRITE(const char *url, webhdfsBuffer *buffer);
-Response launchNnAPPEND(char *url);
-Response launchSETREPLICATION(char *url);
-Response launchDnAPPEND(const char *url, webhdfsBuffer *buffer);
+struct Response {
+    struct ResponseBuffer *body;
+    struct ResponseBuffer *header;
+};
+
+/**
+ * Create and initialize a ResponseBuffer
+ *
+ * @param buffer Pointer pointing to new created ResponseBuffer handle
+ * @return 0 for success, non-zero value to indicate error
+ */
+int initResponseBuffer(struct ResponseBuffer **buffer) __attribute__ ((warn_unused_result));
+
+/**
+ * Free the given ResponseBuffer
+ *
+ * @param buffer The ResponseBuffer to free
+ */
+void freeResponseBuffer(struct ResponseBuffer *buffer);
+
+/**
+ * Free the given Response
+ *
+ * @param resp The Response to free
+ */
+void freeResponse(struct Response *resp);
+
+/**
+ * Send the MKDIR request to NameNode using the given URL. 
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for MKDIR operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchMKDIR(const char *url,
+                struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the RENAME request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for RENAME operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchRENAME(const char *url,
+                 struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the CHMOD request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for CHMOD operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchCHMOD(const char *url,
+                struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the GetFileStatus request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for GetFileStatus operation
+ * @param response Response handle to store response returned from the NameNode,
+ *                 containing either file status or exception information
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchGFS(const char *url,
+              struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the LS (LISTSTATUS) request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for LISTSTATUS operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchLS(const char *url,
+             struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the DELETE request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for DELETE operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchDELETE(const char *url,
+                 struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the CHOWN request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for CHOWN operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchCHOWN(const char *url,
+                struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the OPEN request to NameNode using the given URL, 
+ * asking for reading a file (within a range). 
+ * The NameNode first redirects the request to the datanode
+ * that holds the corresponding first block of the file (within a range),
+ * and the datanode returns the content of the file through the HTTP connection.
+ *
+ * @param url The URL for OPEN operation
+ * @param resp The response holding user's buffer. 
+               The file content will be written into the buffer.
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchOPEN(const char *url,
+               struct Response* resp) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the SETTIMES request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for SETTIMES operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchUTIMES(const char *url,
+                 struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the WRITE/CREATE request to NameNode using the given URL.
+ * The NameNode will choose the writing target datanodes 
+ * and return the first datanode in the pipeline as response
+ *
+ * @param url The URL for WRITE/CREATE operation connecting to NameNode
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchNnWRITE(const char *url,
+                  struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the WRITE request along with to-write content to 
+ * the corresponding DataNode using the given URL. 
+ * The DataNode will write the data and return the response.
+ *
+ * @param url The URL for WRITE operation connecting to DataNode
+ * @param buffer The webhdfsBuffer containing data to be written to hdfs
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchDnWRITE(const char *url, struct webhdfsBuffer *buffer,
+                  struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the WRITE (APPEND) request to NameNode using the given URL. 
+ * The NameNode determines the DataNode for appending and 
+ * sends its URL back as response.
+ *
+ * @param url The URL for APPEND operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchNnAPPEND(const char *url, struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the SETREPLICATION request to NameNode using the given URL.
+ * The NameNode will execute the operation and return the result as response.
+ *
+ * @param url The URL for SETREPLICATION operation
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchSETREPLICATION(const char *url,
+                         struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Send the APPEND request along with the content to DataNode.
+ * The DataNode will do the appending and return the result as response.
+ *
+ * @param url The URL for APPEND operation connecting to DataNode
+ * @param buffer The webhdfsBuffer containing data to be appended
+ * @param response Response handle to store response returned from the NameNode
+ * @return 0 for success, non-zero value to indicate error
+ */
+int launchDnAPPEND(const char *url, struct webhdfsBuffer *buffer,
+                   struct Response **response) __attribute__ ((warn_unused_result));
+
+/**
+ * Call sys_errlist to get the error message string for the given error code
+ *
+ * @param errnoval  The error code value
+ * @return          The error message string mapped to the given error code
+ */
+const char *hdfs_strerror(int errnoval);
 
 #endif //_HDFS_HTTP_CLIENT_H_

hadoop-hdfs-project/hadoop-hdfs/src/contrib/libwebhdfs/src/hdfs_http_query.c

@@ -22,233 +22,381 @@
 #include <stdio.h>
 #include <errno.h>
 
-#define NUM_OF_PERMISSION_BITS 4
-#define NUM_OF_PORT_BITS 6
-#define NUM_OF_REPLICATION_BITS 6
-
-static char *prepareQUERY(const char *host, int nnPort, const char *srcpath, const char *OP, const char *user) {
-    size_t length;
-    char *url;
-    const char *const protocol = "http://";
-    const char *const prefix = "/webhdfs/v1";
-    char *temp;
-    char *port;
-    port= (char*) malloc(NUM_OF_PORT_BITS);
-    if (!port) {
-        return NULL;
-    }
-    sprintf(port,"%d",nnPort);
-    if (user != NULL) {
-        length = strlen(protocol) + strlen(host) + strlen(":") + strlen(port) + strlen(prefix) + strlen(srcpath) + strlen ("?op=") + strlen(OP) + strlen("&user.name=") + strlen(user);
-    } else {
-        length = strlen(protocol) + strlen(host) + strlen(":") + strlen(port) + strlen(prefix) + strlen(srcpath) +  strlen ("?op=") + strlen(OP);
-    }
-    
-    temp = (char*) malloc(length + 1);
-    if (!temp) {
-        return NULL;
-    }
-    strcpy(temp,protocol);
-    temp = strcat(temp,host);
-    temp = strcat(temp,":");
-    temp = strcat(temp,port);
-    temp = strcat(temp,prefix);
-    temp = strcat(temp,srcpath);
-    temp = strcat(temp,"?op=");
-    temp = strcat(temp,OP);
-    if (user) {
-        temp = strcat(temp,"&user.name=");
-        temp = strcat(temp,user);
-    }
-    url = temp;
-    return url;
-}
-
+#define PERM_STR_LEN 4  // "644" + one byte for NUL
+#define SHORT_STR_LEN 6 // 65535 + NUL
+#define LONG_STR_LEN 21 // 2^64-1 = 18446744073709551615 + NUL
 
-static int decToOctal(int decNo) {
-    int octNo=0;
-    int expo =0;
-    while (decNo != 0)  {
-        octNo = ((decNo % 8) * pow(10,expo)) + octNo;
-        decNo = decNo / 8;
-        expo++;
+/**
+ * Create query based on NameNode hostname,
+ * NameNode port, path, operation and other parameters
+ *
+ * @param host          NameNode hostName
+ * @param nnPort        Port of NameNode
+ * @param path          Absolute path for the corresponding file
+ * @param op            Operations
+ * @param paraNum       Number of remaining parameters
+ * @param paraNames     Names of remaining parameters
+ * @param paraValues    Values of remaining parameters
+ * @param url           Holding the created URL
+ * @return 0 on success and non-zero value to indicate error
+ */
+static int createQueryURL(const char *host, unsigned int nnPort,
+                          const char *path, const char *op, int paraNum,
+                          const char **paraNames, const char **paraValues,
+                          char **queryUrl)
+{
+    size_t length = 0;
+    int i = 0, offset = 0, ret = 0;
+    char *url = NULL;
+    const char *protocol = "http://";
+    const char *prefix = "/webhdfs/v1";
+    
+    if (!paraNames || !paraValues) {
+        return EINVAL;
+    }
+    length = strlen(protocol) + strlen(host) + strlen(":") +
+                SHORT_STR_LEN + strlen(prefix) + strlen(path) +
+                strlen ("?op=") + strlen(op);
+    for (i = 0; i < paraNum; i++) {
+        if (paraNames[i] && paraValues[i]) {
+            length += 2 + strlen(paraNames[i]) + strlen(paraValues[i]);
+        }
+    }
+    url = malloc(length);   // The '\0' has already been included
+                            // when using SHORT_STR_LEN
+    if (!url) {
+        return ENOMEM;
+    }
+    
+    offset = snprintf(url, length, "%s%s:%d%s%s?op=%s",
+                      protocol, host, nnPort, prefix, path, op);
+    if (offset >= length || offset < 0) {
+        ret = EIO;
+        goto done;
+    }
+    for (i = 0; i < paraNum; i++) {
+        if (!paraNames[i] || !paraValues[i] || paraNames[i][0] == '\0' ||
+            paraValues[i][0] == '\0') {
+            continue;
+        }
+        offset += snprintf(url + offset, length - offset,
+                           "&%s=%s", paraNames[i], paraValues[i]);
+        if (offset >= length || offset < 0) {
+            ret = EIO;
+            goto done;
+        }
     }
-    return octNo;
+done:
+    if (ret) {
+        free(url);
+        return ret;
+    }
+    *queryUrl = url;
+    return 0;
 }
 
-
-char *prepareMKDIR(const char *host, int nnPort, const char *dirsubpath, const char *user) {
-    return prepareQUERY(host, nnPort, dirsubpath, "MKDIRS", user);
+int createUrlForMKDIR(const char *host, int nnPort,
+                      const char *path, const char *user, char **url)
+{
+    const char *userPara = "user.name";
+    return createQueryURL(host, nnPort, path, "MKDIRS", 1,
+                          &userPara, &user, url);
 }
 
-
-char *prepareMKDIRwithMode(const char *host, int nnPort, const char *dirsubpath, int mode, const char *user) {
-    char *url;
-    char *permission;
-    permission = (char*) malloc(NUM_OF_PERMISSION_BITS);
-    if (!permission) {
-        return NULL;
-    }
-    mode = decToOctal(mode);
-    sprintf(permission,"%d",mode);
-    url = prepareMKDIR(host, nnPort, dirsubpath, user);
-    url = realloc(url,(strlen(url) + strlen("&permission=") + strlen(permission) + 1));
-    if (!url) {
-        return NULL;
-    }
-    url = strcat(url,"&permission=");
-    url = strcat(url,permission);
-    return url;
+int createUrlForGetFileStatus(const char *host, int nnPort, const char *path,
+                              const char *user, char **url)
+{
+    const char *userPara = "user.name";
+    return createQueryURL(host, nnPort, path, "GETFILESTATUS", 1,
+                          &userPara, &user, url);
 }
 
+int createUrlForLS(const char *host, int nnPort, const char *path,
+                   const char *user, char **url)
+{
+    const char *userPara = "user.name";
+    return createQueryURL(host, nnPort, path, "LISTSTATUS",
+                          1, &userPara, &user, url);
+}
 
-char *prepareRENAME(const char *host, int nnPort, const char *srcpath, const char *destpath, const char *user) {
-    char *url;
-    url = prepareQUERY(host, nnPort, srcpath, "RENAME", user);
-    url = realloc(url,(strlen(url) + strlen("&destination=") + strlen(destpath) + 1));
-    if (!url) {
-        return NULL;
-    }
-    url = strcat(url,"&destination=");
-    url = strcat(url,destpath);
-    return url;
+int createUrlForNnAPPEND(const char *host, int nnPort, const char *path,
+                         const char *user, char **url)
+{
+    const char *userPara = "user.name";
+    return createQueryURL(host, nnPort, path, "APPEND",
+                          1, &userPara, &user, url);
 }
 
-char *prepareGFS(const char *host, int nnPort, const char *dirsubpath, const char *user) {
-    return (prepareQUERY(host, nnPort, dirsubpath, "GETFILESTATUS", user));
+int createUrlForMKDIRwithMode(const char *host, int nnPort, const char *path,
+                              int mode, const char *user, char **url)
+{
+    int strlength;
+    char permission[PERM_STR_LEN];
+    const char *paraNames[2], *paraValues[2];
+    
+    paraNames[0] = "permission";
+    paraNames[1] = "user.name";
+    memset(permission, 0, PERM_STR_LEN);
+    strlength = snprintf(permission, PERM_STR_LEN, "%o", mode);
+    if (strlength < 0 || strlength >= PERM_STR_LEN) {
+        return EIO;
+    }
+    paraValues[0] = permission;
+    paraValues[1] = user;
+    
+    return createQueryURL(host, nnPort, path, "MKDIRS", 2,
+                          paraNames, paraValues, url);
 }
 
-char *prepareLS(const char *host, int nnPort, const char *dirsubpath, const char *user) {
-    return (prepareQUERY(host, nnPort, dirsubpath, "LISTSTATUS", user));
+int createUrlForRENAME(const char *host, int nnPort, const char *srcpath,
+                         const char *destpath, const char *user, char **url)
+{
+    const char *paraNames[2], *paraValues[2];
+    paraNames[0] = "destination";
+    paraNames[1] = "user.name";
+    paraValues[0] = destpath;
+    paraValues[1] = user;
+    
+    return createQueryURL(host, nnPort, srcpath,
+                          "RENAME", 2, paraNames, paraValues, url);
 }
 
-char *prepareCHMOD(const char *host, int nnPort, const char *dirsubpath, int mode, const char *user) {
-    char *url;
-    char *permission;
-    permission = (char*) malloc(NUM_OF_PERMISSION_BITS);
-    if (!permission) {
-        return NULL;
-    }
-    mode &= 0x3FFF;
-    mode = decToOctal(mode);
-    sprintf(permission,"%d",mode);
-    url = prepareQUERY(host, nnPort, dirsubpath, "SETPERMISSION", user);
-    url = realloc(url,(strlen(url) + strlen("&permission=") + strlen(permission) + 1));
-    if (!url) {
-        return NULL;
+int createUrlForCHMOD(const char *host, int nnPort, const char *path,
+                      int mode, const char *user, char **url)
+{
+    int strlength;
+    char permission[PERM_STR_LEN];
+    const char *paraNames[2], *paraValues[2];
+    
+    paraNames[0] = "permission";
+    paraNames[1] = "user.name";
+    memset(permission, 0, PERM_STR_LEN);
+    strlength = snprintf(permission, PERM_STR_LEN, "%o", mode);
+    if (strlength < 0 || strlength >= PERM_STR_LEN) {
+        return EIO;
     }
-    url = strcat(url,"&permission=");
-    url = strcat(url,permission);
-    return url;
+    paraValues[0] = permission;
+    paraValues[1] = user;
+    
+    return createQueryURL(host, nnPort, path, "SETPERMISSION",
+                          2, paraNames, paraValues, url);
 }
 
-char *prepareDELETE(const char *host, int nnPort, const char *dirsubpath, int recursive, const char *user) {
-    char *url = (prepareQUERY(host, nnPort, dirsubpath, "DELETE", user));
-    char *recursiveFlag = (char *)malloc(6);
-    if (!recursive) {
-        strcpy(recursiveFlag, "false");
+int createUrlForDELETE(const char *host, int nnPort, const char *path,
+                       int recursive, const char *user, char **url)
+{
+    const char *paraNames[2], *paraValues[2];
+    paraNames[0] = "recursive";
+    paraNames[1] = "user.name";
+    if (recursive) {
+        paraValues[0] = "true";
     } else {
-        strcpy(recursiveFlag, "true");
-    }
-    url = (char *) realloc(url, strlen(url) + strlen("&recursive=") + strlen(recursiveFlag) + 1);
-    if (!url) {
-        return NULL;
+        paraValues[0] = "false";
     }
+    paraValues[1] = user;
     
-    strcat(url, "&recursive=");
-    strcat(url, recursiveFlag);
-    return url;
+    return createQueryURL(host, nnPort, path, "DELETE",
+                          2, paraNames, paraValues, url);
 }
 
-char *prepareCHOWN(const char *host, int nnPort, const char *dirsubpath, const char *owner, const char *group, const char *user) {
-    char *url;
-    url = prepareQUERY(host, nnPort, dirsubpath, "SETOWNER", user);
-    if (!url) {
-        return NULL;
-    }
-    if(owner != NULL) {
-        url = realloc(url,(strlen(url) + strlen("&owner=") + strlen(owner) + 1));
-        url = strcat(url,"&owner=");
-        url = strcat(url,owner);
-    }
-    if (group != NULL) {
-        url = realloc(url,(strlen(url) + strlen("&group=") + strlen(group) + 1));
-        url = strcat(url,"&group=");
-        url = strcat(url,group);
-    }
-    return url;
+int createUrlForCHOWN(const char *host, int nnPort, const char *path,
+                      const char *owner, const char *group,
+                      const char *user, char **url)
+{
+    const char *paraNames[3], *paraValues[3];
+    paraNames[0] = "owner";
+    paraNames[1] = "group";
+    paraNames[2] = "user.name";
+    paraValues[0] = owner;
+    paraValues[1] = group;
+    paraValues[2] = user;
+    
+    return createQueryURL(host, nnPort, path, "SETOWNER",
+                          3, paraNames, paraValues, url);
 }
 
-char *prepareOPEN(const char *host, int nnPort, const char *dirsubpath, const char *user, size_t offset, size_t length) {
-    char *base_url = prepareQUERY(host, nnPort, dirsubpath, "OPEN", user);
-    char *url = (char *) malloc(strlen(base_url) + strlen("&offset=") + 15 + strlen("&length=") + 15);
-    if (!url) {
-        return NULL;
+int createUrlForOPEN(const char *host, int nnPort, const char *path,
+                     const char *user, size_t offset, size_t length, char **url)
+{
+    int strlength;
+    char offsetStr[LONG_STR_LEN], lengthStr[LONG_STR_LEN];
+    const char *paraNames[3], *paraValues[3];
+    
+    paraNames[0] = "offset";
+    paraNames[1] = "length";
+    paraNames[2] = "user.name";
+    memset(offsetStr, 0, LONG_STR_LEN);
+    memset(lengthStr, 0, LONG_STR_LEN);
+    strlength = snprintf(offsetStr, LONG_STR_LEN, "%lu", offset);
+    if (strlength < 0 || strlength >= LONG_STR_LEN) {
+        return EIO;
     }
-    sprintf(url, "%s&offset=%ld&length=%ld", base_url, offset, length);
-    return url;
+    strlength = snprintf(lengthStr, LONG_STR_LEN, "%lu", length);
+    if (strlength < 0 || strlength >= LONG_STR_LEN) {
+        return EIO;
+    }
+    paraValues[0] = offsetStr;
+    paraValues[1] = lengthStr;
+    paraValues[2] = user;
+    
+    return createQueryURL(host, nnPort, path, "OPEN",
+                          3, paraNames, paraValues, url);
 }
 
-char *prepareUTIMES(const char *host, int nnPort, const char *dirsubpath, long unsigned mTime, long unsigned aTime, const char *user) {
-    char *url;
-    char *modTime;
-    char *acsTime;
-    modTime = (char*) malloc(12);
-    acsTime = (char*) malloc(12);
-    url = prepareQUERY(host, nnPort, dirsubpath, "SETTIMES", user);
-    sprintf(modTime,"%lu",mTime);
-    sprintf(acsTime,"%lu",aTime);
-    url = realloc(url,(strlen(url) + strlen("&modificationtime=") + strlen(modTime) + strlen("&accesstime=") + strlen(acsTime) + 1));
-    if (!url) {
-        return NULL;
+int createUrlForUTIMES(const char *host, int nnPort, const char *path,
+                       long unsigned mTime, long unsigned aTime,
+                       const char *user, char **url)
+{
+    int strlength;
+    char modTime[LONG_STR_LEN], acsTime[LONG_STR_LEN];
+    const char *paraNames[3], *paraValues[3];
+    
+    memset(modTime, 0, LONG_STR_LEN);
+    memset(acsTime, 0, LONG_STR_LEN);
+    strlength = snprintf(modTime, LONG_STR_LEN, "%lu", mTime);
+    if (strlength < 0 || strlength >= LONG_STR_LEN) {
+        return EIO;
     }
-    url = strcat(url, "&modificationtime=");
-    url = strcat(url, modTime);
-    url = strcat(url,"&accesstime=");
-    url = strcat(url, acsTime);
-    return url;
+    strlength = snprintf(acsTime, LONG_STR_LEN, "%lu", aTime);
+    if (strlength < 0 || strlength >= LONG_STR_LEN) {
+        return EIO;
+    }
+    paraNames[0] = "modificationtime";
+    paraNames[1] = "accesstime";
+    paraNames[2] = "user.name";
+    paraValues[0] = modTime;
+    paraValues[1] = acsTime;
+    paraValues[2] = user;
+    
+    return createQueryURL(host, nnPort, path, "SETTIMES",
+                          3, paraNames, paraValues, url);
 }
 
-char *prepareNnWRITE(const char *host, int nnPort, const char *dirsubpath, const char *user, int16_t replication, size_t blockSize) {
-    char *url;
-    url = prepareQUERY(host, nnPort, dirsubpath, "CREATE", user);
-    url = realloc(url, (strlen(url) + strlen("&overwrite=true") + 1));
-    if (!url) {
-        return NULL;
-    }
-    url = strcat(url, "&overwrite=true");
+int createUrlForNnWRITE(const char *host, int nnPort,
+                        const char *path, const char *user,
+                        int16_t replication, size_t blockSize, char **url)
+{
+    int strlength;
+    char repStr[SHORT_STR_LEN], blockSizeStr[LONG_STR_LEN];
+    const char *paraNames[4], *paraValues[4];
+    
+    memset(repStr, 0, SHORT_STR_LEN);
+    memset(blockSizeStr, 0, LONG_STR_LEN);
     if (replication > 0) {
-        url = realloc(url, (strlen(url) + strlen("&replication=") + 6));
-        if (!url) {
-            return NULL;
+        strlength = snprintf(repStr, SHORT_STR_LEN, "%u", replication);
+        if (strlength < 0 || strlength >= SHORT_STR_LEN) {
+            return EIO;
         }
-        sprintf(url, "%s&replication=%d", url, replication);
     }
     if (blockSize > 0) {
-        url = realloc(url, (strlen(url) + strlen("&blocksize=") + 16));
-        if (!url) {
-            return NULL;
+        strlength = snprintf(blockSizeStr, LONG_STR_LEN, "%lu", blockSize);
+        if (strlength < 0 || strlength >= LONG_STR_LEN) {
+            return EIO;
+        }
+    }
+    paraNames[0] = "overwrite";
+    paraNames[1] = "replication";
+    paraNames[2] = "blocksize";
+    paraNames[3] = "user.name";
+    paraValues[0] = "true";
+    paraValues[1] = repStr;
+    paraValues[2] = blockSizeStr;
+    paraValues[3] = user;
+    
+    return createQueryURL(host, nnPort, path, "CREATE",
+                          4, paraNames, paraValues, url);
+}
+
+int createUrlForSETREPLICATION(const char *host, int nnPort,
+                               const char *path, int16_t replication,
+                               const char *user, char **url)
+{
+    char repStr[SHORT_STR_LEN];
+    const char *paraNames[2], *paraValues[2];
+    int strlength;
+
+    memset(repStr, 0, SHORT_STR_LEN);
+    if (replication > 0) {
+        strlength = snprintf(repStr, SHORT_STR_LEN, "%u", replication);
+        if (strlength < 0 || strlength >= SHORT_STR_LEN) {
+            return EIO;
         }
-        sprintf(url, "%s&blocksize=%ld", url, blockSize);
     }
-    return url;
+    paraNames[0] = "replication";
+    paraNames[1] = "user.name";
+    paraValues[0] = repStr;
+    paraValues[1] = user;
+    
+    return createQueryURL(host, nnPort, path, "SETREPLICATION",
+                          2, paraNames, paraValues, url);
 }
 
-char *prepareNnAPPEND(const char *host, int nnPort, const char *dirsubpath, const char *user) {
-    return (prepareQUERY(host, nnPort, dirsubpath, "APPEND", user));
+int createUrlForGetBlockLocations(const char *host, int nnPort,
+                                  const char *path, size_t offset,
+                                  size_t length, const char *user, char **url)
+{
+    char offsetStr[LONG_STR_LEN], lengthStr[LONG_STR_LEN];
+    const char *paraNames[3], *paraValues[3];
+    int strlength;
+    
+    memset(offsetStr, 0, LONG_STR_LEN);
+    memset(lengthStr, 0, LONG_STR_LEN);
+    if (offset > 0) {
+        strlength = snprintf(offsetStr, LONG_STR_LEN, "%lu", offset);
+        if (strlength < 0 || strlength >= LONG_STR_LEN) {
+            return EIO;
+        }
+    }
+    if (length > 0) {
+        strlength = snprintf(lengthStr, LONG_STR_LEN, "%lu", length);
+        if (strlength < 0 || strlength >= LONG_STR_LEN) {
+            return EIO;
+        }
+    }
+    paraNames[0] = "offset";
+    paraNames[1] = "length";
+    paraNames[2] = "user.name";
+    paraValues[0] = offsetStr;
+    paraValues[1] = lengthStr;
+    paraValues[2] = user;
+    
+    return createQueryURL(host, nnPort, path, "GET_BLOCK_LOCATIONS",
+                          3, paraNames, paraValues, url);
 }
 
-char *prepareSETREPLICATION(const char *host, int nnPort, const char *path, int16_t replication, const char *user)
+int createUrlForReadFromDatanode(const char *dnHost, int dnPort,
+                                 const char *path, size_t offset,
+                                 size_t length, const char *user,
+                                 const char *namenodeRpcAddr, char **url)
 {
-    char *url = prepareQUERY(host, nnPort, path, "SETREPLICATION", user);
-    char *replicationNum = (char *) malloc(NUM_OF_REPLICATION_BITS);
-    sprintf(replicationNum, "%u", replication);
-    url = realloc(url, strlen(url) + strlen("&replication=") + strlen(replicationNum)+ 1);
-    if (!url) {
-        return NULL;
+    char offsetStr[LONG_STR_LEN], lengthStr[LONG_STR_LEN];
+    const char *paraNames[4], *paraValues[4];
+    int strlength;
+    
+    memset(offsetStr, 0, LONG_STR_LEN);
+    memset(lengthStr, 0, LONG_STR_LEN);
+    if (offset > 0) {
+        strlength = snprintf(offsetStr, LONG_STR_LEN, "%lu", offset);
+        if (strlength < 0 || strlength >= LONG_STR_LEN) {
+            return EIO;
+        }
     }
+    if (length > 0) {
+        strlength = snprintf(lengthStr, LONG_STR_LEN, "%lu", length);
+        if (strlength < 0 || strlength >= LONG_STR_LEN) {
+            return EIO;
+        }
+    }
+    
+    paraNames[0] = "offset";
+    paraNames[1] = "length";
+    paraNames[2] = "user.name";
+    paraNames[3] = "namenoderpcaddress";
+    paraValues[0] = offsetStr;
+    paraValues[1] = lengthStr;
+    paraValues[2] = user;
+    paraValues[3] = namenodeRpcAddr;
     
-    url = strcat(url, "&replication=");
-    url = strcat(url, replicationNum);
-    return url;
+    return createQueryURL(dnHost, dnPort, path, "OPEN",
+                          4, paraNames, paraValues, url);
 }

hadoop-hdfs-project/hadoop-hdfs/src/contrib/libwebhdfs/src/hdfs_http_query.h

@@ -20,22 +20,221 @@
 #ifndef _HDFS_HTTP_QUERY_H_
 #define _HDFS_HTTP_QUERY_H_
 
-#include <stdint.h>
-#include <stdio.h>
-
-char *prepareMKDIR(const char *host, int nnPort, const char *dirsubpath, const char *user);
-char *prepareMKDIRwithMode(const char *host, int nnPort, const char *dirsubpath, int mode, const char *user);
-char *prepareRENAME(const char *host, int nnPort, const char *srcpath, const char *destpath, const char *user);
-char *prepareCHMOD(const char *host, int nnPort, const char *dirsubpath, int mode, const char *user);
-char *prepareGFS(const char *host, int nnPort, const char *dirsubpath, const char *user);
-char *prepareLS(const char *host, int nnPort, const char *dirsubpath, const char *user);
-char *prepareDELETE(const char *host, int nnPort, const char *dirsubpath, int recursive, const char *user);
-char *prepareCHOWN(const char *host, int nnPort, const char *dirsubpath, const char *owner, const char *group, const char *user);
-char *prepareOPEN(const char *host, int nnPort, const char *dirsubpath, const char *user, size_t offset, size_t length);
-char *prepareUTIMES(const char *host, int nnPort, const char *dirsubpath, long unsigned mTime, long unsigned aTime, const char *user);
-char *prepareNnWRITE(const char *host, int nnPort, const char *dirsubpath, const char *user, int16_t replication, size_t blockSize);
-char *prepareNnAPPEND(const char *host, int nnPort, const char *dirsubpath, const char *user);
-char *prepareSETREPLICATION(const char *host, int nnPort, const char *path, int16_t replication, const char *user);
+#include <unistd.h> /* for size_t */
+#include <inttypes.h> /* for int16_t */
+
+/**
+ * Create the URL for a MKDIR request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the dir to create
+ * @param user User name
+ * @param url Holding the generated URL for MKDIR request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForMKDIR(const char *host, int nnPort,
+                      const char *path, const char *user,
+                      char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a MKDIR (with mode) request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the dir to create
+ * @param mode Mode of MKDIR
+ * @param user User name
+ * @param url Holding the generated URL for MKDIR request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForMKDIRwithMode(const char *host, int nnPort, const char *path,
+                              int mode, const char *user,
+                              char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a RENAME request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param srcpath Source path
+ * @param dstpath Destination path
+ * @param user User name
+ * @param url Holding the generated URL for RENAME request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForRENAME(const char *host, int nnPort, const char *srcpath,
+                       const char *dstpath, const char *user,
+                       char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a CHMOD request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Target path
+ * @param mode New mode for the file
+ * @param user User name
+ * @param url Holding the generated URL for CHMOD request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForCHMOD(const char *host, int nnPort, const char *path,
+                      int mode, const char *user,
+                      char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a GETFILESTATUS request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the target file
+ * @param user User name
+ * @param url Holding the generated URL for GETFILESTATUS request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForGetFileStatus(const char *host, int nnPort,
+                              const char *path, const char *user,
+                              char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a LISTSTATUS request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the directory for listing
+ * @param user User name
+ * @param url Holding the generated URL for LISTSTATUS request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForLS(const char *host, int nnPort,
+                   const char *path, const char *user,
+                   char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a DELETE request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the file to be deletected
+ * @param recursive Whether or not to delete in a recursive way
+ * @param user User name
+ * @param url Holding the generated URL for DELETE request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForDELETE(const char *host, int nnPort, const char *path,
+                       int recursive, const char *user,
+                       char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a CHOWN request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the target
+ * @param owner New owner
+ * @param group New group
+ * @param user User name
+ * @param url Holding the generated URL for CHOWN request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForCHOWN(const char *host, int nnPort, const char *path,
+                      const char *owner, const char *group, const char *user,
+                      char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a OPEN/READ request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the file to read
+ * @param user User name
+ * @param offset Offset for reading (the start position for this read)
+ * @param length Length of the file to read
+ * @param url Holding the generated URL for OPEN/READ request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForOPEN(const char *host, int nnPort, const char *path,
+                     const char *user, size_t offset, size_t length,
+                     char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a UTIMES (update time) request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the file for updating time
+ * @param mTime Modified time to set
+ * @param aTime Access time to set
+ * @param user User name
+ * @param url Holding the generated URL for UTIMES request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForUTIMES(const char *host, int nnPort, const char *path,
+                       long unsigned mTime, long unsigned aTime,
+                       const char *user,
+                       char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a WRITE/CREATE request (sent to NameNode)
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the dir to create
+ * @param user User name
+ * @param replication Number of replication of the file
+ * @param blockSize Size of the block for the file
+ * @param url Holding the generated URL for WRITE request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForNnWRITE(const char *host, int nnPort, const char *path,
+                        const char *user, int16_t replication, size_t blockSize,
+                        char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for an APPEND request (sent to NameNode)
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the file for appending
+ * @param user User name
+ * @param url Holding the generated URL for APPEND request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForNnAPPEND(const char *host, int nnPort,
+                         const char *path, const char *user,
+                         char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a SETREPLICATION request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the target file
+ * @param replication New replication number
+ * @param user User name
+ * @param url Holding the generated URL for SETREPLICATION request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForSETREPLICATION(const char *host, int nnPort, const char *path,
+                               int16_t replication, const char *user,
+                               char **url) __attribute__ ((warn_unused_result));
+
+/**
+ * Create the URL for a GET_BLOCK_LOCATIONS request
+ *
+ * @param host The hostname of the NameNode
+ * @param nnPort Port of the NameNode
+ * @param path Path of the target file
+ * @param offset The offset in the file
+ * @param length Length of the file content
+ * @param user User name
+ * @param url Holding the generated URL for GET_BLOCK_LOCATIONS request
+ * @return 0 on success and non-zero value on errors
+ */
+int createUrlForGetBlockLocations(const char *host, int nnPort,
+                            const char *path, size_t offset,
+                            size_t length, const char *user,
+                            char **url) __attribute__ ((warn_unused_result));
 
 
 #endif  //_HDFS_HTTP_QUERY_H_

hadoop-hdfs-project/hadoop-hdfs/src/contrib/libwebhdfs/src/hdfs_json_parser.c

@@ -25,6 +25,11 @@
 #include <ctype.h>
 #include <jansson.h>
 
+static const char * const temporaryRedirectCode = "307 TEMPORARY_REDIRECT";
+static const char * const twoHundredOKCode = "200 OK";
+static const char * const twoHundredOneCreatedCode = "201 Created";
+static const char * const httpHeaderString = "HTTP/1.1";
+
 /**
  * Exception information after calling JSON operations
  */
@@ -34,9 +39,6 @@ struct jsonException {
   const char *message;
 };
 
-static hdfsFileInfo *parseJsonGFS(json_t *jobj, hdfsFileInfo *fileStat,
-                           int *numEntries, const char *operation);
-
 static void dotsToSlashes(char *str)
 {
     for (; *str != '\0'; str++) {
@@ -45,8 +47,9 @@ static void dotsToSlashes(char *str)
     }
 }
 
-int printJsonExceptionV(struct jsonException *exc, int noPrintFlags,
-                        const char *fmt, va_list ap)
+/** Print out the JSON exception information */
+static int printJsonExceptionV(struct jsonException *exc, int noPrintFlags,
+                               const char *fmt, va_list ap)
 {
     char *javaClassName = NULL;
     int excErrno = EINTERNAL, shouldPrint = 0;
@@ -74,11 +77,23 @@ int printJsonExceptionV(struct jsonException *exc, int noPrintFlags,
     return excErrno;
 }
 
-int printJsonException(struct jsonException *exc, int noPrintFlags,
-                       const char *fmt, ...)
+/**
+ * Print out JSON exception information.
+ *
+ * @param exc             The exception information to print and free
+ * @param noPrintFlags    Flags which determine which exceptions we should NOT
+ *                        print.
+ * @param fmt             Printf-style format list
+ * @param ...             Printf-style varargs
+ *
+ * @return                The POSIX error number associated with the exception
+ *                        object.
+ */
+static int printJsonException(struct jsonException *exc, int noPrintFlags,
+                              const char *fmt, ...)
 {
     va_list ap;
-    int ret;
+    int ret = 0;
     
     va_start(ap, fmt);
     ret = printJsonExceptionV(exc, noPrintFlags, fmt, ap);
@@ -86,81 +101,20 @@ int printJsonException(struct jsonException *exc, int noPrintFlags,
     return ret;
 }
 
-static hdfsFileInfo *json_parse_array(json_t *jobj, char *key, hdfsFileInfo *fileStat, int *numEntries, const char *operation) {
-    int arraylen = json_array_size(jobj);                      //Getting the length of the array
-    *numEntries = arraylen;
-    if (!key) {
-        return NULL;
-    }
-    if(arraylen > 0) {
-        fileStat = (hdfsFileInfo *)realloc(fileStat,sizeof(hdfsFileInfo)*arraylen);
-    }
-    json_t *jvalue;
-    int i;
-    for (i=0; i< arraylen; i++) {
-        jvalue = json_array_get(jobj, i);            //Getting the array element at position i
-        if (json_is_array(jvalue)) {                 // array within an array - program should never come here for now
-            json_parse_array(jvalue, NULL, &fileStat[i], numEntries, operation);
-        }
-        else if (json_is_object(jvalue)) {           // program will definitely come over here
-            parseJsonGFS(jvalue, &fileStat[i], numEntries, operation);
-        }
-        else {
-            return NULL;                               // program will never come over here for now
-        }
-    }
-    *numEntries = arraylen;
-    return fileStat;
-}
-
-int parseBoolean(char *response) {
-    json_t *root;
-    json_error_t error;
-    size_t flags = 0;
-    int result = 0;
-    const char *key;
-    json_t *value;
-    root = json_loads(response, flags, &error);
-    void *iter = json_object_iter(root);
-    while(iter)  {
-        key = json_object_iter_key(iter);
-        value = json_object_iter_value(iter);
-        switch (json_typeof(value))  {
-            case JSON_TRUE:
-                result = 1;
-                break;
-            default:
-                result = 0;
-                break;
-        }
-        iter = json_object_iter_next(root, iter);
-    }
-    return result;
-}
-
-int parseMKDIR(char *response) {
-    return (parseBoolean(response));
-}
-
-int parseRENAME(char *response) {
-    return (parseBoolean(response));
-}
-
-int parseDELETE(char *response) {
-    return (parseBoolean(response));
-}
-
-struct jsonException *parseJsonException(json_t *jobj) {
-    const char *key;
-    json_t *value;
+/** Parse the exception information from JSON */
+static struct jsonException *parseJsonException(json_t *jobj)
+{
+    const char *key = NULL;
+    json_t *value = NULL;
     struct jsonException *exception = NULL;
+    void *iter = NULL;
     
     exception = calloc(1, sizeof(*exception));
     if (!exception) {
         return NULL;
     }
     
-    void *iter = json_object_iter(jobj);
+    iter = json_object_iter(jobj);
     while (iter) {
         key = json_object_iter_key(iter);
         value = json_object_iter_value(iter);
@@ -175,23 +129,31 @@ struct jsonException *parseJsonException(json_t *jobj) {
         
         iter = json_object_iter_next(jobj, iter);
     }
-    
     return exception;
 }
 
-struct jsonException *parseException(const char *content) {
-    if (!content) {
-        return NULL;
-    }
-    
+/** 
+ * Parse the exception information which is presented in JSON
+ * 
+ * @param content   Exception information in JSON
+ * @return          jsonException for printing out
+ */
+static struct jsonException *parseException(const char *content)
+{
     json_error_t error;
     size_t flags = 0;
-    const char *key;
+    const char *key = NULL;
     json_t *value;
-    json_t *jobj = json_loads(content, flags, &error);
+    json_t *jobj;
+    struct jsonException *exception = NULL;
     
+    if (!content) {
+        return NULL;
+    }
+    jobj = json_loads(content, flags, &error);
     if (!jobj) {
-        fprintf(stderr, "JSon parsing failed\n");
+        fprintf(stderr, "JSon parsing error: on line %d: %s\n",
+                error.line, error.text);
         return NULL;
     }
     void *iter = json_object_iter(jobj);
@@ -199,254 +161,503 @@ struct jsonException *parseException(const char *content) {
         key = json_object_iter_key(iter);
         value = json_object_iter_value(iter);
         
-        if (!strcmp(key, "RemoteException") && json_typeof(value) == JSON_OBJECT) {
-            return parseJsonException(value);
+        if (!strcmp(key, "RemoteException") &&
+                    json_typeof(value) == JSON_OBJECT) {
+            exception = parseJsonException(value);
+            break;
         }
         iter = json_object_iter_next(jobj, iter);
     }
-    return NULL;
+    
+    json_decref(jobj);
+    return exception;
 }
 
-static hdfsFileInfo *parseJsonGFS(json_t *jobj, hdfsFileInfo *fileStat,
-                                  int *numEntries, const char *operation)
+/**
+ * Parse the response information which uses TRUE/FALSE 
+ * to indicate whether the operation succeeded
+ *
+ * @param response  Response information
+ * @return          0 to indicate success
+ */
+static int parseBoolean(const char *response)
 {
-    const char *tempstr;
-    const char *key;
-    json_t *value;
-    void *iter = json_object_iter(jobj);
-    while(iter)  {
-        key = json_object_iter_key(iter);
-        value = json_object_iter_value(iter);
-        
-        switch (json_typeof(value)) {
-            case JSON_INTEGER:
-                if(!strcmp(key,"accessTime")) {
-                    fileStat->mLastAccess = (time_t)(json_integer_value(value)/1000);
-                } else if (!strcmp(key,"blockSize")) {
-                    fileStat->mBlockSize = (tOffset)json_integer_value(value);
-                } else if (!strcmp(key,"length")) {
-                    fileStat->mSize = (tOffset)json_integer_value(value);
-                } else if(!strcmp(key,"modificationTime")) {
-                    fileStat->mLastMod = (time_t)(json_integer_value(value)/1000);
-                } else if (!strcmp(key,"replication")) {
-                    fileStat->mReplication = (short)json_integer_value(value);
-                }
-                break;
-                
-            case JSON_STRING:
-                if(!strcmp(key,"group")) {
-                    fileStat->mGroup=(char *)json_string_value(value);
-                } else if (!strcmp(key,"owner")) {
-                    fileStat->mOwner=(char *)json_string_value(value);
-                } else if (!strcmp(key,"pathSuffix")) {
-                    fileStat->mName=(char *)json_string_value(value);
-                } else if (!strcmp(key,"permission")) {
-                    tempstr=(char *)json_string_value(value);
-                    fileStat->mPermissions = (short)strtol(tempstr,(char **)NULL,8);
-                } else if (!strcmp(key,"type")) {
-                    char *cvalue = (char *)json_string_value(value);
-                    if (!strcmp(cvalue, "DIRECTORY")) {
-                        fileStat->mKind = kObjectKindDirectory;
-                    } else {
-                        fileStat->mKind = kObjectKindFile;
-                    }
-                }
-                break;
-                
-            case JSON_OBJECT:
-                if(!strcmp(key,"FileStatus")) {
-                    parseJsonGFS(value, fileStat, numEntries, operation);
-                } else if (!strcmp(key,"FileStatuses")) {
-                    fileStat = parseJsonGFS(value, &fileStat[0], numEntries, operation);
-                } else if (!strcmp(key,"RemoteException")) {
-                    //Besides returning NULL, we also need to print the exception information
-                    struct jsonException *exception = parseJsonException(value);
-                    if (exception) {
-                        errno = printJsonException(exception, PRINT_EXC_ALL, "Calling WEBHDFS (%s)", operation);
-                    }
-                    
-                    if(fileStat != NULL) {
-                        free(fileStat);
-                        fileStat = NULL;
-                    }
-                }
-                break;
-                
-            case JSON_ARRAY:
-                if (!strcmp(key,"FileStatus")) {
-                    fileStat = json_parse_array(value,(char *) key,fileStat,numEntries, operation);
-                }
-                break;
-                
-            default:
-                if(fileStat != NULL) {
-                    free(fileStat);
-                    fileStat = NULL;
-                }
-        }
-        iter = json_object_iter_next(jobj, iter);
+    json_t *root, *value;
+    json_error_t error;
+    size_t flags = 0;
+    int result = 0;
+    
+    root = json_loads(response, flags, &error);
+    if (!root) {
+        fprintf(stderr, "JSon parsing error: on line %d: %s\n",
+                error.line, error.text);
+        return EIO;
+    }
+    void *iter = json_object_iter(root);
+    value = json_object_iter_value(iter);
+    if (json_typeof(value) == JSON_TRUE)  {
+        result = 0;
+    } else {
+        result = EIO;  // FALSE means error in remote NN/DN
     }
-    return fileStat;
+    json_decref(root);
+    return result;
 }
 
+int parseMKDIR(const char *response)
+{
+    return parseBoolean(response);
+}
+
+int parseRENAME(const char *response)
+{
+    return parseBoolean(response);
+}
+
+int parseDELETE(const char *response)
+{
+    return parseBoolean(response);
+}
 
-int checkHeader(char *header, const char *content, const char *operation) {
+int parseSETREPLICATION(const char *response)
+{
+    return parseBoolean(response);
+}
+
+/**
+ * Check the header of response to see if it's 200 OK
+ * 
+ * @param header    Header information for checking
+ * @param content   Stores exception information if there are errors
+ * @param operation Indicate the operation for exception printing
+ * @return 0 for success
+ */
+static int checkHeader(const char *header, const char *content,
+                       const char *operation)
+{
     char *result = NULL;
-    char delims[] = ":";
-    char *responseCode= "200 OK";
-    if(header == '\0' || strncmp(header, "HTTP/", strlen("HTTP/"))) {
-        return 0;
+    const char delims[] = ":";
+    char *savepter;
+    int ret = 0;
+    
+    if (!header || strncmp(header, "HTTP/", strlen("HTTP/"))) {
+        return EINVAL;
     }
-    if(!(strstr(header, responseCode)) || !(header = strstr(header, "Content-Length"))) {
+    if (!(strstr(header, twoHundredOKCode)) ||
+       !(result = strstr(header, "Content-Length"))) {
         struct jsonException *exc = parseException(content);
         if (exc) {
-            errno = printJsonException(exc, PRINT_EXC_ALL, "Calling WEBHDFS (%s)", operation);
+            ret = printJsonException(exc, PRINT_EXC_ALL,
+                                       "Calling WEBHDFS (%s)", operation);
+        } else {
+            ret = EIO;
         }
-        return 0;
+        return ret;
     }
-    result = strtok(header, delims);
-    result = strtok(NULL,delims);
+    result = strtok_r(result, delims, &savepter);
+    result = strtok_r(NULL, delims, &savepter);
     while (isspace(*result)) {
         result++;
     }
-    if(strcmp(result,"0")) {                 //Content-Length should be equal to 0
-        return 1;
-    } else {
-        return 0;
+    // Content-Length should be equal to 0,
+    // and the string should be "0\r\nServer"
+    if (strncmp(result, "0\r\n", 3)) {
+        ret = EIO;
     }
+    return ret;
 }
 
-int parseOPEN(const char *header, const char *content) {
-    const char *responseCode1 = "307 TEMPORARY_REDIRECT";
-    const char *responseCode2 = "200 OK";
-    if(header == '\0' || strncmp(header,"HTTP/",strlen("HTTP/"))) {
-        return -1;
-    }
-    if(!(strstr(header,responseCode1) && strstr(header, responseCode2))) {
-        struct jsonException *exc = parseException(content);
-        if (exc) {
-            //if the exception is an IOException and it is because the offset is out of the range
-            //do not print out the exception
-            if (!strcasecmp(exc->exception, "IOException") && strstr(exc->message, "out of the range")) {
-                return 0;
-            }
-            errno = printJsonException(exc, PRINT_EXC_ALL, "Calling WEBHDFS (OPEN)");
-        }
-        return -1;
-    }
-    
-    return 1;
-}
-
-int parseCHMOD(char *header, const char *content) {
+int parseCHMOD(const char *header, const char *content)
+{
     return checkHeader(header, content, "CHMOD");
 }
 
-
-int parseCHOWN(char *header, const char *content) {
+int parseCHOWN(const char *header, const char *content)
+{
     return checkHeader(header, content, "CHOWN");
 }
 
-int parseUTIMES(char *header, const char *content) {
-    return checkHeader(header, content, "UTIMES");
+int parseUTIMES(const char *header, const char *content)
+{
+    return checkHeader(header, content, "SETTIMES");
 }
 
-
-int checkIfRedirect(const char *const headerstr, const char *content, const char *operation) {
-    char *responseCode = "307 TEMPORARY_REDIRECT";
-    char * locTag = "Location";
-    char * tempHeader;
-    if(headerstr == '\0' || strncmp(headerstr,"HTTP/", 5)) {
-        return 0;
-    }
-    if(!(tempHeader = strstr(headerstr,responseCode))) {
-        //process possible exception information
+/**
+ * Check if the header contains correct information
+ * ("307 TEMPORARY_REDIRECT" and "Location")
+ * 
+ * @param header    Header for parsing
+ * @param content   Contains exception information 
+ *                  if the remote operation failed
+ * @param operation Specify the remote operation when printing out exception
+ * @return 0 for success
+ */
+static int checkRedirect(const char *header,
+                         const char *content, const char *operation)
+{
+    const char *locTag = "Location";
+    int ret = 0, offset = 0;
+    
+    // The header must start with "HTTP/1.1"
+    if (!header || strncmp(header, httpHeaderString,
+                           strlen(httpHeaderString))) {
+        return EINVAL;
+    }
+    
+    offset += strlen(httpHeaderString);
+    while (isspace(header[offset])) {
+        offset++;
+    }
+    // Looking for "307 TEMPORARY_REDIRECT" in header
+    if (strncmp(header + offset, temporaryRedirectCode,
+                strlen(temporaryRedirectCode))) {
+        // Process possible exception information
         struct jsonException *exc = parseException(content);
         if (exc) {
-            errno = printJsonException(exc, PRINT_EXC_ALL, "Calling WEBHDFS (%s)", operation);
+            ret = printJsonException(exc, PRINT_EXC_ALL,
+                                     "Calling WEBHDFS (%s)", operation);
+        } else {
+            ret = EIO;
         }
-        return 0;
+        return ret;
     }
-    if(!(strstr(tempHeader,locTag))) {
-        return 0;
+    // Here we just simply check if header contains "Location" tag,
+    // detailed processing is in parseDnLoc
+    if (!(strstr(header, locTag))) {
+        ret = EIO;
     }
-    return 1;
+    return ret;
 }
 
-
-int parseNnWRITE(const char *header, const char *content) {
-    return checkIfRedirect(header, content, "Write(NameNode)");
+int parseNnWRITE(const char *header, const char *content)
+{
+    return checkRedirect(header, content, "Write(NameNode)");
 }
 
+int parseNnAPPEND(const char *header, const char *content)
+{
+    return checkRedirect(header, content, "Append(NameNode)");
+}
 
-int parseNnAPPEND(const char *header, const char *content) {
-    return checkIfRedirect(header, content, "Append(NameNode)");
+/** 0 for success , -1 for out of range, other values for error */
+int parseOPEN(const char *header, const char *content)
+{
+    int ret = 0, offset = 0;
+    
+    if (!header || strncmp(header, httpHeaderString,
+                           strlen(httpHeaderString))) {
+        return EINVAL;
+    }
+    
+    offset += strlen(httpHeaderString);
+    while (isspace(header[offset])) {
+        offset++;
+    }
+    if (strncmp(header + offset, temporaryRedirectCode,
+                strlen(temporaryRedirectCode)) ||
+        !strstr(header, twoHundredOKCode)) {
+        struct jsonException *exc = parseException(content);
+        if (exc) {
+            // If the exception is an IOException and it is because
+            // the offset is out of the range, do not print out the exception
+            if (!strcasecmp(exc->exception, "IOException") &&
+                    strstr(exc->message, "out of the range")) {
+                ret = -1;
+            } else {
+                ret = printJsonException(exc, PRINT_EXC_ALL,
+                                       "Calling WEBHDFS (OPEN)");
+            }
+        } else {
+            ret = EIO;
+        }
+    }
+    return ret;
 }
 
-char *parseDnLoc(char *content) {
-    char delims[] = "\r\n";
-    char *url = NULL;
-    char *DnLocation = NULL;
-    char *savepter;
-    DnLocation = strtok_r(content, delims, &savepter);
-    while (DnLocation && strncmp(DnLocation, "Location:", strlen("Location:"))) {
-        DnLocation = strtok_r(NULL, delims, &savepter);
+int parseDnLoc(char *content, char **dn)
+{
+    char *url = NULL, *dnLocation = NULL, *savepter, *tempContent;
+    const char *prefix = "Location: http://";
+    const char *prefixToRemove = "Location: ";
+    const char *delims = "\r\n";
+    
+    tempContent = strdup(content);
+    if (!tempContent) {
+        return ENOMEM;
     }
-    if (!DnLocation) {
-        return NULL;
+    
+    dnLocation = strtok_r(tempContent, delims, &savepter);
+    while (dnLocation && strncmp(dnLocation, "Location:",
+                                 strlen("Location:"))) {
+        dnLocation = strtok_r(NULL, delims, &savepter);
     }
-    DnLocation = strstr(DnLocation, "http");
-    if (!DnLocation) {
-        return NULL;
+    if (!dnLocation) {
+        return EIO;
     }
-    url = malloc(strlen(DnLocation) + 1);
+    
+    while (isspace(*dnLocation)) {
+        dnLocation++;
+    }
+    if (strncmp(dnLocation, prefix, strlen(prefix))) {
+        return EIO;
+    }
+    url = strdup(dnLocation + strlen(prefixToRemove));
     if (!url) {
-        return NULL;
+        return ENOMEM;
     }
-    strcpy(url, DnLocation);
-    return url;
+    *dn = url;
+    return 0;
 }
 
-int parseDnWRITE(const char *header, const char *content) {
-    char *responseCode = "201 Created";
-    fprintf(stderr, "\nheaderstr is: %s\n", header);
-    if(header == '\0' || strncmp(header,"HTTP/",strlen("HTTP/"))) {
-        return 0;
+int parseDnWRITE(const char *header, const char *content)
+{
+    int ret = 0;
+    if (header == NULL || header[0] == '\0' ||
+                         strncmp(header, "HTTP/", strlen("HTTP/"))) {
+        return EINVAL;
     }
-    if(!(strstr(header,responseCode))) {
+    if (!(strstr(header, twoHundredOneCreatedCode))) {
         struct jsonException *exc = parseException(content);
         if (exc) {
-            errno = printJsonException(exc, PRINT_EXC_ALL, "Calling WEBHDFS (WRITE(DataNode))");
+            ret = printJsonException(exc, PRINT_EXC_ALL,
+                                     "Calling WEBHDFS (WRITE(DataNode))");
+        } else {
+            ret = EIO;
         }
-        return 0;
     }
-    return 1;
+    return ret;
 }
 
-int parseDnAPPEND(const char *header, const char *content) {
-    char *responseCode = "200 OK";
-    if(header == '\0' || strncmp(header, "HTTP/", strlen("HTTP/"))) {
-        return 0;
+int parseDnAPPEND(const char *header, const char *content)
+{
+    int ret = 0;
+    
+    if (header == NULL || header[0] == '\0' ||
+                         strncmp(header, "HTTP/", strlen("HTTP/"))) {
+        return EINVAL;
     }
-    if(!(strstr(header, responseCode))) {
+    if (!(strstr(header, twoHundredOKCode))) {
         struct jsonException *exc = parseException(content);
         if (exc) {
-            errno = printJsonException(exc, PRINT_EXC_ALL, "Calling WEBHDFS (APPEND(DataNode))");
+            ret = printJsonException(exc, PRINT_EXC_ALL,
+                                     "Calling WEBHDFS (APPEND(DataNode))");
+        } else {
+            ret = EIO;
+        }
+    }
+    return ret;
+}
+
+/**
+ * Retrieve file status from the JSON object 
+ *
+ * @param jobj          JSON object for parsing, which contains 
+ *                      file status information
+ * @param fileStat      hdfsFileInfo handle to hold file status information
+ * @return 0 on success
+ */
+static int parseJsonForFileStatus(json_t *jobj, hdfsFileInfo *fileStat)
+{
+    const char *key, *tempstr;
+    json_t *value;
+    void *iter = NULL;
+    
+    iter = json_object_iter(jobj);
+    while (iter) {
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+        
+        if (!strcmp(key, "accessTime")) {
+            // json field contains time in milliseconds,
+            // hdfsFileInfo is counted in seconds
+            fileStat->mLastAccess = json_integer_value(value) / 1000;
+        } else if (!strcmp(key, "blockSize")) {
+            fileStat->mBlockSize = json_integer_value(value);
+        } else if (!strcmp(key, "length")) {
+            fileStat->mSize = json_integer_value(value);
+        } else if (!strcmp(key, "modificationTime")) {
+            fileStat->mLastMod = json_integer_value(value) / 1000;
+        } else if (!strcmp(key, "replication")) {
+            fileStat->mReplication = json_integer_value(value);
+        } else if (!strcmp(key, "group")) {
+            fileStat->mGroup = strdup(json_string_value(value));
+            if (!fileStat->mGroup) {
+                return ENOMEM;
+            }
+        } else if (!strcmp(key, "owner")) {
+            fileStat->mOwner = strdup(json_string_value(value));
+            if (!fileStat->mOwner) {
+                return ENOMEM;
+            }
+        } else if (!strcmp(key, "pathSuffix")) {
+            fileStat->mName = strdup(json_string_value(value));
+            if (!fileStat->mName) {
+                return ENOMEM;
+            }
+        } else if (!strcmp(key, "permission")) {
+            tempstr = json_string_value(value);
+            fileStat->mPermissions = (short) strtol(tempstr, NULL, 8);
+        } else if (!strcmp(key, "type")) {
+            tempstr = json_string_value(value);
+            if (!strcmp(tempstr, "DIRECTORY")) {
+                fileStat->mKind = kObjectKindDirectory;
+            } else {
+                fileStat->mKind = kObjectKindFile;
+            }
         }
-        return 0;
+        // Go to the next key-value pair in the json object
+        iter = json_object_iter_next(jobj, iter);
     }
-    return 1;
+    return 0;
 }
 
-hdfsFileInfo *parseGFS(char *str, hdfsFileInfo *fileStat, int *numEntries) {
+int parseGFS(const char *response, hdfsFileInfo *fileStat, int printError)
+{
+    int ret = 0, printFlag;
     json_error_t error;
     size_t flags = 0;
-    json_t *jobj = json_loads(str, flags, &error);
-    fileStat = parseJsonGFS(jobj, fileStat, numEntries, "GETPATHSTATUS/LISTSTATUS");
-    return fileStat;
+    json_t *jobj, *value;
+    const char *key;
+    void *iter = NULL;
+    
+    if (!response || !fileStat) {
+        return EIO;
+    }
+    jobj = json_loads(response, flags, &error);
+    if (!jobj) {
+        fprintf(stderr, "error while parsing json: on line %d: %s\n",
+                error.line, error.text);
+        return EIO;
+    }
+    iter = json_object_iter(jobj);
+    key = json_object_iter_key(iter);
+    value = json_object_iter_value(iter);
+    if (json_typeof(value) == JSON_OBJECT) {
+        if (!strcmp(key, "RemoteException")) {
+            struct jsonException *exception = parseJsonException(value);
+            if (exception) {
+                if (printError) {
+                    printFlag = PRINT_EXC_ALL;
+                } else {
+                    printFlag = NOPRINT_EXC_FILE_NOT_FOUND |
+                                NOPRINT_EXC_ACCESS_CONTROL |
+                                NOPRINT_EXC_PARENT_NOT_DIRECTORY;
+                }
+                ret = printJsonException(exception, printFlag,
+                                         "Calling WEBHDFS GETFILESTATUS");
+            } else {
+                ret = EIO;
+            }
+        } else if (!strcmp(key, "FileStatus")) {
+            ret = parseJsonForFileStatus(value, fileStat);
+        } else {
+            ret = EIO;
+        }
+        
+    } else {
+        ret = EIO;
+    }
+    
+    json_decref(jobj);
+    return ret;
 }
 
-int parseSETREPLICATION(char *response) {
-    return (parseBoolean(response));
+/**
+ * Parse the JSON array. Called to parse the result of 
+ * the LISTSTATUS operation. Thus each element of the JSON array is 
+ * a JSON object with the information of a file entry contained 
+ * in the folder.
+ *
+ * @param jobj          The JSON array to be parsed
+ * @param fileStat      The hdfsFileInfo handle used to 
+ *                      store a group of file information
+ * @param numEntries    Capture the number of files in the folder
+ * @return              0 for success
+ */
+static int parseJsonArrayForFileStatuses(json_t *jobj, hdfsFileInfo **fileStat,
+                                         int *numEntries)
+{
+    json_t *jvalue = NULL;
+    int i = 0, ret = 0, arraylen = 0;
+    hdfsFileInfo *fileInfo = NULL;
+    
+    arraylen = (int) json_array_size(jobj);
+    if (arraylen > 0) {
+        fileInfo = calloc(arraylen, sizeof(hdfsFileInfo));
+        if (!fileInfo) {
+            return ENOMEM;
+        }
+    }
+    for (i = 0; i < arraylen; i++) {
+        //Getting the array element at position i
+        jvalue = json_array_get(jobj, i);
+        if (json_is_object(jvalue)) {
+            ret = parseJsonForFileStatus(jvalue, &fileInfo[i]);
+            if (ret) {
+                goto done;
+            }
+        } else {
+            ret = EIO;
+            goto done;
+        }
+    }
+done:
+    if (ret) {
+        free(fileInfo);
+    } else {
+        *numEntries = arraylen;
+        *fileStat = fileInfo;
+    }
+    return ret;
 }
 
+int parseLS(const char *response, hdfsFileInfo **fileStats, int *numOfEntries)
+{
+    int ret = 0;
+    json_error_t error;
+    size_t flags = 0;
+    json_t *jobj, *value;
+    const char *key;
+    void *iter = NULL;
+    
+    if (!response || response[0] == '\0' || !fileStats) {
+        return EIO;
+    }
+    jobj = json_loads(response, flags, &error);
+    if (!jobj) {
+        fprintf(stderr, "error while parsing json: on line %d: %s\n",
+                error.line, error.text);
+        return EIO;
+    }
+    
+    iter = json_object_iter(jobj);
+    key = json_object_iter_key(iter);
+    value = json_object_iter_value(iter);
+    if (json_typeof(value) == JSON_OBJECT) {
+        if (!strcmp(key, "RemoteException")) {
+            struct jsonException *exception = parseJsonException(value);
+            if (exception) {
+                ret = printJsonException(exception, PRINT_EXC_ALL,
+                                         "Calling WEBHDFS GETFILESTATUS");
+            } else {
+                ret = EIO;
+            }
+        } else if (!strcmp(key, "FileStatuses")) {
+            iter = json_object_iter(value);
+            value = json_object_iter_value(iter);
+            if (json_is_array(value)) {
+                ret = parseJsonArrayForFileStatuses(value, fileStats,
+                                                    numOfEntries);
+            } else {
+                ret = EIO;
+            }
+        } else {
+            ret = EIO;
+        }
+    } else {
+        ret = EIO;
+    }
+    
+    json_decref(jobj);
+    return ret;
+}

hadoop-hdfs-project/hadoop-hdfs/src/contrib/libwebhdfs/src/hdfs_json_parser.h

@@ -18,41 +18,161 @@
 #ifndef _HDFS_JSON_PARSER_H_
 #define _HDFS_JSON_PARSER_H_
 
-struct jsonException;
+/**
+ * Parse the response for MKDIR request. The response uses TRUE/FALSE 
+ * to indicate whether the operation succeeded.
+ *
+ * @param response  The response information to parse.
+ * @return 0 for success
+ */
+int parseMKDIR(const char *response);
 
 /**
- * Print out JSON exception information.
+ * Parse the response for RENAME request. The response uses TRUE/FALSE
+ * to indicate whether the operation succeeded.
  *
- * @param exc             The exception information to print and free
- * @param noPrintFlags    Flags which determine which exceptions we should NOT
- *                        print.
- * @param fmt             Printf-style format list
- * @param ...             Printf-style varargs
+ * @param response  The response information to parse.
+ * @return 0 for success
+ */
+int parseRENAME(const char *response);
+
+/**
+ * Parse the response for DELETE request. The response uses TRUE/FALSE
+ * to indicate whether the operation succeeded.
  *
- * @return                The POSIX error number associated with the exception
- *                        object.
+ * @param response  The response information to parse.
+ * @return 0 for success
  */
-int printJsonException(struct jsonException *exc, int noPrintFlags,
-                       const char *fmt, ...);
+int parseDELETE(const char *response);
 
-int parseMKDIR(char *response);
-int parseRENAME(char *response);
-int parseDELETE (char *response);
-int parseSETREPLICATION(char *response);
+/**
+ * Parse the response for SETREPLICATION request. The response uses TRUE/FALSE
+ * to indicate whether the operation succeeded.
+ *
+ * @param response  The response information to parse.
+ * @return 0 for success
+ */
+int parseSETREPLICATION(const char *response);
 
+/**
+ * Parse the response for OPEN (read) request. A successful operation 
+ * will return "200 OK".
+ *
+ * @param response  The response information for parsing
+ * @return          0 for success , -1 for out of range, other values for error
+ */
 int parseOPEN(const char *header, const char *content);
 
+/**
+ * Parse the response for WRITE (from NameNode) request. 
+ * A successful operation should return "307 TEMPORARY_REDIRECT" in its header.
+ *
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message 
+ *                  sent from NameNode is stored in content
+ * @return          0 for success
+ */
 int parseNnWRITE(const char *header, const char *content);
+
+/**
+ * Parse the response for WRITE (from DataNode) request. 
+ * A successful operation should return "201 Created" in its header.
+ * 
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message
+ *                  sent from DataNode is stored in content
+ * @return          0 for success
+ */
 int parseDnWRITE(const char *header, const char *content);
+
+/**
+ * Parse the response for APPEND (sent from NameNode) request.
+ * A successful operation should return "307 TEMPORARY_REDIRECT" in its header.
+ *
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message
+ *                  sent from NameNode is stored in content
+ * @return          0 for success
+ */
 int parseNnAPPEND(const char *header, const char *content);
+
+/**
+ * Parse the response for APPEND (from DataNode) request.
+ * A successful operation should return "200 OK" in its header.
+ *
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message
+ *                  sent from DataNode is stored in content
+ * @return          0 for success
+ */
 int parseDnAPPEND(const char *header, const char *content);
 
-char* parseDnLoc(char *content);
+/**
+ * Parse the response (from NameNode) to get the location information 
+ * of the DataNode that should be contacted for the following write operation.
+ *
+ * @param content   Content of the http header
+ * @param dn        To store the location of the DataNode for writing
+ * @return          0 for success
+ */
+int parseDnLoc(char *content, char **dn) __attribute__ ((warn_unused_result));
+
+/**
+ * Parse the response for GETFILESTATUS operation.
+ *
+ * @param response      Response to parse. Its detailed format is specified in 
+ *            "http://hadoop.apache.org/docs/stable/webhdfs.html#GETFILESTATUS"
+ * @param fileStat      A hdfsFileInfo handle for holding file information
+ * @param printError    Whether or not print out exception 
+ *                      when file does not exist
+ * @return 0 for success, non-zero value to indicate error
+ */
+int parseGFS(const char *response, hdfsFileInfo *fileStat, int printError);
 
-hdfsFileInfo *parseGFS(char *response, hdfsFileInfo *fileStat, int *numEntries);
+/**
+ * Parse the response for LISTSTATUS operation.
+ *
+ * @param response      Response to parse. Its detailed format is specified in
+ *            "http://hadoop.apache.org/docs/r1.0.3/webhdfs.html#LISTSTATUS"
+ * @param fileStats     Pointer pointing to a list of hdfsFileInfo handles 
+ *                      holding file/dir information in the directory
+ * @param numEntries    After parsing, the value of this parameter indicates
+ *                      the number of file entries.
+ * @return 0 for success, non-zero value to indicate error
+ */
+int parseLS(const char *response, hdfsFileInfo **fileStats, int *numOfEntries);
 
-int parseCHOWN (char *header, const char *content);
-int parseCHMOD (char *header, const char *content);
-int parseUTIMES(char *header, const char *content);
+/**
+ * Parse the response for CHOWN request.
+ * A successful operation should contains "200 OK" in its header, 
+ * and the Content-Length should be 0.
+ *
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message is stored in content
+ * @return          0 for success
+ */
+int parseCHOWN(const char *header, const char *content);
+
+/**
+ * Parse the response for CHMOD request.
+ * A successful operation should contains "200 OK" in its header,
+ * and the Content-Length should be 0.
+ *
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message is stored in content
+ * @return          0 for success
+ */
+int parseCHMOD(const char *header, const char *content);
+
+/**
+ * Parse the response for SETTIMES request.
+ * A successful operation should contains "200 OK" in its header,
+ * and the Content-Length should be 0.
+ *
+ * @param header    The header of the http response
+ * @param content   If failing, the exception message is stored in content
+ * @return          0 for success
+ */
+int parseUTIMES(const char *header, const char *content);
 
-#endif //_FUSE_JSON_PARSER_H
+#endif //_HDFS_JSON_PARSER_H_

hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/jni_helper.c

@@ -146,6 +146,7 @@ static int hashTableInit(void)
             if (hcreate(MAX_HASH_TABLE_ELEM) == 0) {
                 fprintf(stderr, "error creating hashtable, <%d>: %s\n",
                         errno, strerror(errno));
+                UNLOCK_HASH_TABLE();
                 return 0;
             } 
             hashTableInited = 1;