HDFS-10494: libhdfs++: Implement snapshot operations and GetFsStats. Contributed by Anatoli Shein.

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs-tests/test_libhdfs_threaded.c

@@ -197,7 +197,7 @@ static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs,
     }
     if (ret != expected) {
         fprintf(stderr, "hdfsWrite was supposed to write %d bytes, but "
-                "it wrote %d\n", ret, expected);
+                "it wrote %d\n", expected, ret);
         return EIO;
     }
     EXPECT_ZERO(hdfsFlush(fs, file));

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/include/hdfspp/fsinfo.h

@@ -0,0 +1,52 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef HDFSPP_FSINFO_H_
+#define HDFSPP_FSINFO_H_
+
+namespace hdfs {
+
+/**
+ * Information that is assumed to be unchanging about a file system for the duration of
+ * the operations.
+ */
+struct FsInfo {
+
+  unsigned long int     capacity;
+  unsigned long int     used;
+  unsigned long int     remaining;
+  unsigned long int     under_replicated;
+  unsigned long int     corrupt_blocks;
+  unsigned long int     missing_blocks;
+  unsigned long int     missing_repl_one_blocks;
+  unsigned long int     blocks_in_future;
+
+  FsInfo()
+      : capacity(0),
+        used(0),
+        remaining(0),
+        under_replicated(0),
+        corrupt_blocks(0),
+        missing_blocks(0),
+        missing_repl_one_blocks(0),
+        blocks_in_future(0) {
+  }
+};
+
+}
+
+#endif

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/include/hdfspp/hdfs_ext.h

@@ -275,6 +275,49 @@ LIBHDFS_EXTERNAL
 int hdfsPreAttachFileMonitor(libhdfspp_file_event_callback handler, int64_t cookie);
 
 
+/*****************************************************************************
+ *                    HDFS SNAPSHOT FUNCTIONS
+ ****************************************************************************/
+
+/**
+ * Creates a snapshot of a snapshottable directory specified by path
+ *
+ *  @param fs      The filesystem (required)
+ *  @param path    Path to the directory to be snapshotted (must be non-blank)
+ *  @param name    Name to be given to the created snapshot (may be NULL)
+ *  @return        0 on success, corresponding errno on failure
+ **/
+int hdfsCreateSnapshot(hdfsFS fs, const char* path, const char* name);
+
+/**
+ * Deletes the directory snapshot specified by path and name
+ *
+ *  @param fs      The filesystem (required)
+ *  @param path    Path to the snapshotted directory (must be non-blank)
+ *  @param name    Name of the snapshot to be deleted (must be non-blank)
+ *  @return        0 on success, corresponding errno on failure
+ **/
+int hdfsDeleteSnapshot(hdfsFS fs, const char* path, const char* name);
+
+/**
+ * Allows snapshots to be made on the specified directory
+ *
+ *  @param fs      The filesystem (required)
+ *  @param path    Path to the directory to be made snapshottable (must be non-blank)
+ *  @return        0 on success, corresponding errno on failure
+ **/
+int hdfsAllowSnapshot(hdfsFS fs, const char* path);
+
+/**
+ * Disallows snapshots to be made on the specified directory
+ *
+ *  @param fs      The filesystem (required)
+ *  @param path    Path to the directory to be made non-snapshottable (must be non-blank)
+ *  @return        0 on success, corresponding errno on failure
+ **/
+int hdfsDisallowSnapshot(hdfsFS fs, const char* path);
+
+
 #ifdef __cplusplus
 } /* end extern "C" */
 #endif

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/include/hdfspp/hdfspp.h

@@ -23,7 +23,7 @@
 #include "hdfspp/events.h"
 #include "hdfspp/block_location.h"
 #include "hdfspp/statinfo.h"
-
+#include "hdfspp/fsinfo.h"
 
 #include <functional>
 #include <memory>
@@ -179,6 +179,16 @@ class FileSystem {
                   const std::function<void(const Status &, const StatInfo &)> &handler) = 0;
   virtual Status GetFileInfo(const std::string &path, StatInfo & stat_info) = 0;
 
+  /**
+   * Retrieves the file system information as a whole, such as the total raw size of all files in the filesystem
+   * and the raw capacity of the filesystem
+   *
+   *  @param FsInfo      struct to be populated by GetFsStats
+   **/
+  virtual void GetFsStats(
+      const std::function<void(const Status &, const FsInfo &)> &handler) = 0;
+  virtual Status GetFsStats(FsInfo & fs_info) = 0;
+
   /**
    * Retrieves the files contained in a directory and returns the metadata
    * for each of them.
@@ -207,6 +217,50 @@ class FileSystem {
   virtual Status GetBlockLocations(const std::string & path,
     std::shared_ptr<FileBlockLocation> * locations) = 0;
 
+  /*****************************************************************************
+   *                    FILE SYSTEM SNAPSHOT FUNCTIONS
+   ****************************************************************************/
+
+  /**
+   * Creates a snapshot of a snapshottable directory specified by path
+   *
+   *  @param path    Path to the directory to be snapshotted (must be non-empty)
+   *  @param name    Name to be given to the created snapshot (may be empty)
+   **/
+  virtual void CreateSnapshot(const std::string &path, const std::string &name,
+      const std::function<void(const Status &)> &handler) = 0;
+  virtual Status CreateSnapshot(const std::string &path,
+      const std::string &name) = 0;
+
+  /**
+   * Deletes the directory snapshot specified by path and name
+   *
+   *  @param path    Path to the snapshotted directory (must be non-empty)
+   *  @param name    Name of the snapshot to be deleted (must be non-empty)
+   **/
+  virtual void DeleteSnapshot(const std::string &path, const std::string &name,
+      const std::function<void(const Status &)> &handler) = 0;
+  virtual Status DeleteSnapshot(const std::string &path,
+      const std::string &name) = 0;
+
+  /**
+   * Allows snapshots to be made on the specified directory
+   *
+   *  @param path    Path to the directory to be made snapshottable (must be non-empty)
+   **/
+  virtual void AllowSnapshot(const std::string &path,
+      const std::function<void(const Status &)> &handler) = 0;
+  virtual Status AllowSnapshot(const std::string &path) = 0;
+
+  /**
+   * Disallows snapshots to be made on the specified directory
+   *
+   *  @param path    Path to the directory to be made non-snapshottable (must be non-empty)
+   **/
+  virtual void DisallowSnapshot(const std::string &path,
+      const std::function<void(const Status &)> &handler) = 0;
+  virtual Status DisallowSnapshot(const std::string &path) = 0;
+
   /**
    * Note that it is an error to destroy the filesystem from within a filesystem
    * callback.  It will lead to a deadlock and the termination of the process.

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/include/hdfspp/status.h

@@ -58,6 +58,7 @@ class Status {
     kOperationCanceled = static_cast<unsigned>(std::errc::operation_canceled),
     kPermissionDenied = static_cast<unsigned>(std::errc::permission_denied),
     kPathNotFound = static_cast<unsigned>(std::errc::no_such_file_or_directory),
+    kNotADirectory = static_cast<unsigned>(std::errc::not_a_directory),
     kException = 256,
     kAuthenticationFailed = 257,
   };

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/bindings/c/hdfs.cc

@@ -153,6 +153,10 @@ static int Error(const Status &stat) {
       errnum = ENOENT;
       default_message = "No such file or directory";
       break;
+    case Status::Code::kNotADirectory:
+      errnum = ENOTDIR;
+      default_message = "Not a directory";
+      break;
     default:
       errnum = ENOSYS;
       default_message = "Error: unrecognised code";
@@ -323,6 +327,52 @@ int hdfsCloseFile(hdfsFS fs, hdfsFile file) {
   }
 }
 
+tOffset hdfsGetCapacity(hdfsFS fs) {
+  try {
+    errno = 0;
+    if (!CheckSystem(fs)) {
+       return -1;
+    }
+
+    hdfs::FsInfo fs_info;
+    Status stat = fs->get_impl()->GetFsStats(fs_info);
+    if (!stat.ok()) {
+      Error(stat);
+      return -1;
+    }
+    return fs_info.capacity;
+  } catch (const std::exception & e) {
+    ReportException(e);
+    return -1;
+  } catch (...) {
+    ReportCaughtNonException();
+    return -1;
+  }
+}
+
+tOffset hdfsGetUsed(hdfsFS fs) {
+  try {
+    errno = 0;
+    if (!CheckSystem(fs)) {
+       return -1;
+    }
+
+    hdfs::FsInfo fs_info;
+    Status stat = fs->get_impl()->GetFsStats(fs_info);
+    if (!stat.ok()) {
+      Error(stat);
+      return -1;
+    }
+    return fs_info.used;
+  } catch (const std::exception & e) {
+    ReportException(e);
+    return -1;
+  } catch (...) {
+    ReportCaughtNonException();
+    return -1;
+  }
+}
+
 void StatInfoToHdfsFileInfo(hdfsFileInfo * file_info,
                             const hdfs::StatInfo & stat_info) {
   /* file or directory */
@@ -365,10 +415,10 @@ void StatInfoToHdfsFileInfo(hdfsFileInfo * file_info,
   file_info->mGroup = new char[stat_info.group.size() + 1];
   strncpy(file_info->mGroup, stat_info.group.c_str(), stat_info.group.size() + 1);
 
-  /* the permissions associated with the file */
+  /* the permissions associated with the file encoded as an octal number (0777)*/
   file_info->mPermissions = (short) stat_info.permissions;
 
-  /* the last access time for the file in seconds */
+  /* the last access time for the file in seconds since the epoch*/
   file_info->mLastAccess = stat_info.access_time;
 }
 
@@ -444,6 +494,101 @@ void hdfsFreeFileInfo(hdfsFileInfo *hdfsFileInfo, int numEntries)
     delete[] hdfsFileInfo;
 }
 
+int hdfsCreateSnapshot(hdfsFS fs, const char* path, const char* name) {
+  try {
+    errno = 0;
+    if (!CheckSystem(fs)) {
+      return -1;
+    }
+    if (!path) {
+      return Error(Status::InvalidArgument("Argument 'path' cannot be NULL"));
+    }
+    Status stat;
+    if(!name){
+      stat = fs->get_impl()->CreateSnapshot(path, "");
+    } else {
+      stat = fs->get_impl()->CreateSnapshot(path, name);
+    }
+    if (!stat.ok()) {
+      return Error(stat);
+    }
+    return 0;
+  } catch (const std::exception & e) {
+    return ReportException(e);
+  } catch (...) {
+    return ReportCaughtNonException();
+  }
+}
+
+int hdfsDeleteSnapshot(hdfsFS fs, const char* path, const char* name) {
+  try {
+    errno = 0;
+    if (!CheckSystem(fs)) {
+      return -1;
+    }
+    if (!path) {
+      return Error(Status::InvalidArgument("Argument 'path' cannot be NULL"));
+    }
+    if (!name) {
+      return Error(Status::InvalidArgument("Argument 'name' cannot be NULL"));
+    }
+    Status stat;
+    stat = fs->get_impl()->DeleteSnapshot(path, name);
+    if (!stat.ok()) {
+      return Error(stat);
+    }
+    return 0;
+  } catch (const std::exception & e) {
+    return ReportException(e);
+  } catch (...) {
+    return ReportCaughtNonException();
+  }
+}
+
+int hdfsAllowSnapshot(hdfsFS fs, const char* path) {
+  try {
+    errno = 0;
+    if (!CheckSystem(fs)) {
+      return -1;
+    }
+    if (!path) {
+      return Error(Status::InvalidArgument("Argument 'path' cannot be NULL"));
+    }
+    Status stat;
+    stat = fs->get_impl()->AllowSnapshot(path);
+    if (!stat.ok()) {
+      return Error(stat);
+    }
+    return 0;
+  } catch (const std::exception & e) {
+    return ReportException(e);
+  } catch (...) {
+    return ReportCaughtNonException();
+  }
+}
+
+int hdfsDisallowSnapshot(hdfsFS fs, const char* path) {
+  try {
+    errno = 0;
+    if (!CheckSystem(fs)) {
+      return -1;
+    }
+    if (!path) {
+      return Error(Status::InvalidArgument("Argument 'path' cannot be NULL"));
+    }
+    Status stat;
+    stat = fs->get_impl()->DisallowSnapshot(path);
+    if (!stat.ok()) {
+      return Error(stat);
+    }
+    return 0;
+  } catch (const std::exception & e) {
+    return ReportException(e);
+  } catch (...) {
+    return ReportCaughtNonException();
+  }
+}
+
 tSize hdfsPread(hdfsFS fs, hdfsFile file, tOffset position, void *buffer,
                 tSize length) {
   try

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/base64.cc

@@ -25,47 +25,49 @@
 namespace hdfs {
 
 std::string Base64Encode(const std::string &src) {
-  static const char kDictionary[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-                                    "abcdefghijklmnopqrstuvwxyz"
-                                    "0123456789+/";
+  //encoded size is (sizeof(buf) + 2) / 3 * 4
+  static const std::string base64_chars =
+               "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+               "abcdefghijklmnopqrstuvwxyz"
+               "0123456789+/";
+  std::string ret;
+  int i = 0;
+  int j = 0;
+  unsigned char char_array_3[3];
+  unsigned char char_array_4[4];
+  unsigned const char *bytes_to_encode = reinterpret_cast<unsigned const char *>(&src[i]);
+  unsigned int in_len = src.size();
 
-  int encoded_size = (src.size() + 2) / 3 * 4;
-  std::string dst;
-  dst.reserve(encoded_size);
+  while (in_len--) {
+    char_array_3[i++] = *(bytes_to_encode++);
+    if (i == 3) {
+      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+      char_array_4[3] = char_array_3[2] & 0x3f;
 
-  size_t i = 0;
-  while (i + 3 < src.length()) {
-    const char *s = &src[i];
-    const int32_t r[4] = {s[0] >> 2, ((s[0] << 4) | (s[1] >> 4)) & 0x3f,
-                      ((s[1] << 2) | (s[2] >> 6)) & 0x3f, s[2] & 0x3f};
-
-    std::transform(r, r + sizeof(r) / sizeof(int32_t), std::back_inserter(dst),
-                   [&r](unsigned char v) { return kDictionary[v]; });
-    i += 3;
+      for(i = 0; (i <4) ; i++)
+        ret += base64_chars[char_array_4[i]];
+      i = 0;
+    }
   }
 
-  size_t remained = src.length() - i;
-  const char *s = &src[i];
+  if (i)  {
+    for(j = i; j < 3; j++)
+      char_array_3[j] = '\0';
+
+    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+    char_array_4[3] = char_array_3[2] & 0x3f;
+
+    for (j = 0; (j < i + 1); j++)
+      ret += base64_chars[char_array_4[j]];
 
-  switch (remained) {
-  case 0:
-    break;
-  case 1: {
-    char padding[4] = {kDictionary[s[0] >> 2], kDictionary[(s[0] << 4) & 0x3f],
-                       '=', '='};
-    dst.append(padding, sizeof(padding));
-  } break;
-  case 2: {
-    char padding[4] = {kDictionary[src[i] >> 2],
-                       kDictionary[((s[0] << 4) | (s[1] >> 4)) & 0x3f],
-                       kDictionary[(s[1] << 2) & 0x3f], '='};
-    dst.append(padding, sizeof(padding));
-  } break;
-  default:
-    assert("Unreachable");
-    break;
+    while((i++ < 3))
+      ret += '=';
   }
-  return dst;
+  return ret;
 }
 
 }

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/status.cc

@@ -28,6 +28,8 @@ const char * kStatusAccessControlException = "org.apache.hadoop.security.AccessC
 const char * kStatusSaslException = "javax.security.sasl.SaslException";
 const char * kPathNotFoundException = "org.apache.hadoop.fs.InvalidPathException";
 const char * kPathNotFoundException2 = "java.io.FileNotFoundException";
+const char * kPathIsNotDirectoryException = "org.apache.hadoop.fs.PathIsNotDirectoryException";
+const char * kSnapshotException = "org.apache.hadoop.hdfs.protocol.SnapshotException";
 
 Status::Status(int code, const char *msg1) : code_(code) {
   if(msg1) {
@@ -76,6 +78,10 @@ Status Status::Exception(const char *exception_class_name, const char *error_mes
     return Status(kPathNotFound, error_message);
   else if (exception_class_name && (strcmp(exception_class_name, kPathNotFoundException2) == 0))
     return Status(kPathNotFound, error_message);
+  else if (exception_class_name && (strcmp(exception_class_name, kPathIsNotDirectoryException) == 0))
+      return Status(kNotADirectory, error_message);
+  else if (exception_class_name && (strcmp(exception_class_name, kSnapshotException) == 0))
+        return Status(kInvalidArgument, error_message);
   else
     return Status(kException, exception_class_name, error_message);
 }

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/util.cc

@@ -55,13 +55,24 @@ std::string SerializeDelimitedProtobufMessage(const ::google::protobuf::MessageL
 
 
 std::string GetRandomClientName() {
-  unsigned char buf[6];
-
+  /**
+   *  The server is requesting a 16-byte UUID:
+   *  https://github.com/c9n/hadoop/blob/master/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ClientId.java
+   *
+   *  This function generates a 16-byte UUID (version 4):
+   *  https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
+   **/
+  unsigned char buf[16];
   RAND_pseudo_bytes(buf, sizeof(buf));
 
+  //clear the first four bits of byte 6 then set the second bit
+  buf[6] = (buf[6] & 0x0f) | 0x40;
+
+  //clear the second bit of byte 8 and set the first bit
+  buf[8] = (buf[8] & 0xbf) | 0x80;
+
   std::stringstream ss;
-  ss << "libhdfs++_"
-     << Base64Encode(std::string(reinterpret_cast<char *>(buf), sizeof(buf)));
+  ss << std::string(reinterpret_cast<char *>(buf), sizeof(buf));
   return ss.str();
 }
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/filesystem.cc

@@ -79,16 +79,16 @@ const std::string get_effective_user_name(const std::string &user_name) {
   return "unknown_user";
 }
 
-FileSystemImpl::FileSystemImpl(IoService *&io_service, const std::string &user_name,
-                               const Options &options)
-  :   options_(options),
-      io_service_(static_cast<IoServiceImpl *>(io_service)),
-      nn_(&io_service_->io_service(), options,
-      GetRandomClientName(), get_effective_user_name(user_name), kNamenodeProtocol,
-      kNamenodeProtocolVersion), client_name_(GetRandomClientName()),
-      bad_node_tracker_(std::make_shared<BadDataNodeTracker>()),
-      event_handlers_(std::make_shared<LibhdfsEvents>())
-{
+FileSystemImpl::FileSystemImpl(IoService *&io_service, const std::string &user_name, const Options &options) :
+    options_(options), client_name_(GetRandomClientName()), io_service_(
+        static_cast<IoServiceImpl *>(io_service)),
+        nn_(
+          &io_service_->io_service(), options, client_name_,
+          get_effective_user_name(user_name), kNamenodeProtocol,
+          kNamenodeProtocolVersion
+        ), bad_node_tracker_(std::make_shared<BadDataNodeTracker>()),
+        event_handlers_(std::make_shared<LibhdfsEvents>()) {
+
   LOG_TRACE(kFileSystem, << "FileSystemImpl::FileSystemImpl("
                          << FMT_THIS_ADDR << ") called");
 
@@ -396,6 +396,43 @@ Status FileSystemImpl::GetFileInfo(const std::string &path,
   return stat;
 }
 
+void FileSystemImpl::GetFsStats(
+    const std::function<void(const Status &, const FsInfo &)> &handler) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::GetFsStats(" << FMT_THIS_ADDR << ") called");
+
+  nn_.GetFsStats([handler](const Status &stat, const FsInfo &fs_info) {
+    handler(stat, fs_info);
+  });
+}
+
+Status FileSystemImpl::GetFsStats(FsInfo & fs_info) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::[sync]GetFsStats(" << FMT_THIS_ADDR << ") called");
+
+  auto callstate = std::make_shared<std::promise<std::tuple<Status, FsInfo>>>();
+  std::future<std::tuple<Status, FsInfo>> future(callstate->get_future());
+
+  /* wrap async FileSystem::GetFsStats with promise to make it a blocking call */
+  auto h = [callstate](const Status &s, const FsInfo &si) {
+    callstate->set_value(std::make_tuple(s, si));
+  };
+
+  GetFsStats(h);
+
+  /* block until promise is set */
+  auto returnstate = future.get();
+  Status stat = std::get<0>(returnstate);
+  FsInfo info = std::get<1>(returnstate);
+
+  if (!stat.ok()) {
+    return stat;
+  }
+
+  fs_info = info;
+  return stat;
+}
+
 /**
  * Helper function for recursive GetListing calls.
  *
@@ -475,6 +512,157 @@ Status FileSystemImpl::GetListing(const std::string &path, std::shared_ptr<std::
   return stat;
 }
 
+void FileSystemImpl::CreateSnapshot(const std::string &path,
+    const std::string &name,
+    const std::function<void(const Status &)> &handler) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::CreateSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ", name=" << name << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+
+  nn_.CreateSnapshot(path, name, [handler](const Status &stat) {
+    handler(stat);
+  });
+}
+
+Status FileSystemImpl::CreateSnapshot(const std::string &path,
+    const std::string &name) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::[sync]CreateSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ", name=" << name << ") called");
+
+  auto callstate = std::make_shared<std::promise<std::tuple<Status>>>();
+  std::future<std::tuple<Status>> future(callstate->get_future());
+
+  /* wrap async FileSystem::CreateSnapshot with promise to make it a blocking call */
+  auto h = [callstate](const Status &s) {
+    callstate->set_value(std::make_tuple(s));
+  };
+
+  CreateSnapshot(path, name, h);
+
+  /* block until promise is set */
+  auto returnstate = future.get();
+  Status stat = std::get<0>(returnstate);
+
+  return stat;
+}
+
+void FileSystemImpl::DeleteSnapshot(const std::string &path,
+    const std::string &name,
+    const std::function<void(const Status &)> &handler) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::DeleteSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ", name=" << name << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+  if (name.empty()) {
+    handler(Status::InvalidArgument("Argument 'name' cannot be empty"));
+    return;
+  }
+
+  nn_.DeleteSnapshot(path, name, [handler](const Status &stat) {
+    handler(stat);
+  });
+}
+
+Status FileSystemImpl::DeleteSnapshot(const std::string &path,
+    const std::string &name) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::[sync]DeleteSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ", name=" << name << ") called");
+
+  auto callstate = std::make_shared<std::promise<std::tuple<Status>>>();
+  std::future<std::tuple<Status>> future(callstate->get_future());
+
+  /* wrap async FileSystem::DeleteSnapshot with promise to make it a blocking call */
+  auto h = [callstate](const Status &s) {
+    callstate->set_value(std::make_tuple(s));
+  };
+
+  DeleteSnapshot(path, name, h);
+
+  /* block until promise is set */
+  auto returnstate = future.get();
+  Status stat = std::get<0>(returnstate);
+
+  return stat;
+}
+
+void FileSystemImpl::AllowSnapshot(const std::string &path,
+    const std::function<void(const Status &)> &handler) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::AllowSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+
+  nn_.AllowSnapshot(path, [handler](const Status &stat) {
+    handler(stat);
+  });
+}
+
+Status FileSystemImpl::AllowSnapshot(const std::string &path) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::[sync]AllowSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ") called");
+
+  auto callstate = std::make_shared<std::promise<std::tuple<Status>>>();
+  std::future<std::tuple<Status>> future(callstate->get_future());
+
+  /* wrap async FileSystem::AllowSnapshot with promise to make it a blocking call */
+  auto h = [callstate](const Status &s) {
+    callstate->set_value(std::make_tuple(s));
+  };
+
+  AllowSnapshot(path, h);
+
+  /* block until promise is set */
+  auto returnstate = future.get();
+  Status stat = std::get<0>(returnstate);
+
+  return stat;
+}
+
+void FileSystemImpl::DisallowSnapshot(const std::string &path,
+    const std::function<void(const Status &)> &handler) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::DisallowSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+
+  nn_.DisallowSnapshot(path, [handler](const Status &stat) {
+    handler(stat);
+  });
+}
+
+Status FileSystemImpl::DisallowSnapshot(const std::string &path) {
+  LOG_DEBUG(kFileSystem,
+      << "FileSystemImpl::[sync]DisallowSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ") called");
+
+  auto callstate = std::make_shared<std::promise<std::tuple<Status>>>();
+  std::future<std::tuple<Status>> future(callstate->get_future());
+
+  /* wrap async FileSystem::DisallowSnapshot with promise to make it a blocking call */
+  auto h = [callstate](const Status &s) {
+    callstate->set_value(std::make_tuple(s));
+  };
+
+  DisallowSnapshot(path, h);
+
+  /* block until promise is set */
+  auto returnstate = future.get();
+  Status stat = std::get<0>(returnstate);
+
+  return stat;
+}
 
 void FileSystemImpl::WorkerDeleter::operator()(std::thread *t) {
   // It is far too easy to destroy the filesystem (and thus the threadpool)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/filesystem.h

@@ -71,6 +71,17 @@ public:
 
   Status GetFileInfo(const std::string &path, StatInfo & stat_info) override;
 
+  /**
+   * Retrieves the file system information such as the total raw size of all files in the filesystem
+   * and the raw capacity of the filesystem
+   *
+   *  @param FsInfo      struct to be populated by GetFsStats
+   **/
+  void GetFsStats(
+      const std::function<void(const Status &, const FsInfo &)> &handler) override;
+
+  Status GetFsStats(FsInfo & fs_info) override;
+
   void GetListing(
         const std::string &path,
         const std::function<bool(const Status &, std::shared_ptr<std::vector<StatInfo>> &, bool)> &handler) override;
@@ -83,6 +94,46 @@ public:
     std::shared_ptr<FileBlockLocation> * locations) override;
 
 
+  /*****************************************************************************
+   *                    FILE SYSTEM SNAPSHOT FUNCTIONS
+   ****************************************************************************/
+
+  /**
+   * Creates a snapshot of a snapshottable directory specified by path
+   *
+   *  @param path    Path to the directory to be snapshotted (must be non-empty)
+   *  @param name    Name to be given to the created snapshot (may be empty)
+   **/
+  void CreateSnapshot(const std::string &path, const std::string &name,
+      const std::function<void(const Status &)> &handler) override;
+  Status CreateSnapshot(const std::string &path, const std::string &name) override;
+
+  /**
+   * Deletes the directory snapshot specified by path and name
+   *
+   *  @param path    Path to the snapshotted directory (must be non-empty)
+   *  @param name    Name of the snapshot to be deleted (must be non-empty)
+   **/
+  void DeleteSnapshot(const std::string &path, const std::string &name,
+        const std::function<void(const Status &)> &handler) override;
+  Status DeleteSnapshot(const std::string &path, const std::string &name) override;
+
+  /**
+   * Allows snapshots to be made on the specified directory
+   *
+   *  @param path    Path to the directory to be made snapshottable (must be non-empty)
+   **/
+  void AllowSnapshot(const std::string &path, const std::function<void(const Status &)> &handler) override;
+  Status AllowSnapshot(const std::string &path) override;
+
+  /**
+   * Disallows snapshots to be made on the specified directory
+   *
+   *  @param path    Path to the directory to be made non-snapshottable (must be non-empty)
+   **/
+  void DisallowSnapshot(const std::string &path, const std::function<void(const Status &)> &handler) override;
+  Status DisallowSnapshot(const std::string &path) override;
+
   void SetFsEventCallback(fs_event_callback callback) override;
 
   /* add a new thread to handle asio requests, return number of threads in pool
@@ -97,7 +148,7 @@ public:
 
 private:
   const Options options_;
-
+  const std::string client_name_;
   std::string cluster_name_;
   /**
    *  The IoService must be the first member variable to ensure that it gets
@@ -106,7 +157,6 @@ private:
    **/
   std::unique_ptr<IoServiceImpl> io_service_;
   NameNodeOperations nn_;
-  const std::string client_name_;
   std::shared_ptr<BadDataNodeTracker> bad_node_tracker_;
 
   struct WorkerDeleter {

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/namenode_operations.cc

@@ -131,6 +131,28 @@ void NameNodeOperations::GetFileInfo(const std::string & path,
   });
 }
 
+void NameNodeOperations::GetFsStats(
+    std::function<void(const Status &, const FsInfo &)> handler) {
+  using ::hadoop::hdfs::GetFsStatusRequestProto;
+  using ::hadoop::hdfs::GetFsStatsResponseProto;
+
+  LOG_TRACE(kFileSystem,
+      << "NameNodeOperations::GetFsStats(" << FMT_THIS_ADDR << ") called");
+
+  GetFsStatusRequestProto req;
+  auto resp = std::make_shared<GetFsStatsResponseProto>();
+
+  namenode_.GetFsStats(&req, resp, [resp, handler](const Status &stat) {
+    if (stat.ok()) {
+      struct FsInfo fs_info;
+      GetFsStatsResponseProtoToFsInfo(fs_info, resp);
+      handler(stat, fs_info);
+    } else {
+      handler(stat, FsInfo());
+    }
+  });
+}
+
 void NameNodeOperations::GetListing(
     const std::string & path,
     std::function<void(const Status &, std::shared_ptr<std::vector<StatInfo>> &, bool)> handler,
@@ -176,6 +198,108 @@ void NameNodeOperations::GetListing(
       });
 }
 
+void NameNodeOperations::CreateSnapshot(const std::string & path,
+    const std::string & name, std::function<void(const Status &)> handler) {
+  using ::hadoop::hdfs::CreateSnapshotRequestProto;
+  using ::hadoop::hdfs::CreateSnapshotResponseProto;
+
+  LOG_TRACE(kFileSystem,
+      << "NameNodeOperations::CreateSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ", name=" << name << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+
+  CreateSnapshotRequestProto req;
+  req.set_snapshotroot(path);
+  if (!name.empty()) {
+    req.set_snapshotname(name);
+  }
+
+  auto resp = std::make_shared<CreateSnapshotResponseProto>();
+
+  namenode_.CreateSnapshot(&req, resp,
+      [resp, handler, path](const Status &stat) {
+        handler(stat);
+      });
+}
+
+void NameNodeOperations::DeleteSnapshot(const std::string & path,
+    const std::string & name, std::function<void(const Status &)> handler) {
+  using ::hadoop::hdfs::DeleteSnapshotRequestProto;
+  using ::hadoop::hdfs::DeleteSnapshotResponseProto;
+
+  LOG_TRACE(kFileSystem,
+      << "NameNodeOperations::DeleteSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ", name=" << name << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+  if (name.empty()) {
+    handler(Status::InvalidArgument("Argument 'name' cannot be empty"));
+    return;
+  }
+
+  DeleteSnapshotRequestProto req;
+  req.set_snapshotroot(path);
+  req.set_snapshotname(name);
+
+  auto resp = std::make_shared<DeleteSnapshotResponseProto>();
+
+  namenode_.DeleteSnapshot(&req, resp,
+      [resp, handler, path](const Status &stat) {
+        handler(stat);
+      });
+}
+
+void NameNodeOperations::AllowSnapshot(const std::string & path, std::function<void(const Status &)> handler) {
+  using ::hadoop::hdfs::AllowSnapshotRequestProto;
+  using ::hadoop::hdfs::AllowSnapshotResponseProto;
+
+  LOG_TRACE(kFileSystem,
+      << "NameNodeOperations::AllowSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+
+  AllowSnapshotRequestProto req;
+  req.set_snapshotroot(path);
+
+  auto resp = std::make_shared<AllowSnapshotResponseProto>();
+
+  namenode_.AllowSnapshot(&req, resp,
+      [resp, handler, path](const Status &stat) {
+        handler(stat);
+      });
+}
+
+void NameNodeOperations::DisallowSnapshot(const std::string & path, std::function<void(const Status &)> handler) {
+  using ::hadoop::hdfs::DisallowSnapshotRequestProto;
+  using ::hadoop::hdfs::DisallowSnapshotResponseProto;
+
+  LOG_TRACE(kFileSystem,
+      << "NameNodeOperations::DisallowSnapshot(" << FMT_THIS_ADDR << ", path=" << path << ") called");
+
+  if (path.empty()) {
+    handler(Status::InvalidArgument("Argument 'path' cannot be empty"));
+    return;
+  }
+
+  DisallowSnapshotRequestProto req;
+  req.set_snapshotroot(path);
+
+  auto resp = std::make_shared<DisallowSnapshotResponseProto>();
+
+  namenode_.DisallowSnapshot(&req, resp,
+      [resp, handler, path](const Status &stat) {
+        handler(stat);
+      });
+}
+
 void NameNodeOperations::SetFsEventCallback(fs_event_callback callback) {
   engine_.SetFsEventCallback(callback);
 }
@@ -197,4 +321,19 @@ void NameNodeOperations::HdfsFileStatusProtoToStatInfo(
   stat_info.children_num = fs.childrennum();
 }
 
+void NameNodeOperations::GetFsStatsResponseProtoToFsInfo(
+    hdfs::FsInfo & fs_info,
+    const std::shared_ptr<::hadoop::hdfs::GetFsStatsResponseProto> & fs) {
+  fs_info.capacity = fs->capacity();
+  fs_info.used = fs->used();
+  fs_info.remaining = fs->remaining();
+  fs_info.under_replicated = fs->under_replicated();
+  fs_info.corrupt_blocks = fs->corrupt_blocks();
+  fs_info.missing_blocks = fs->missing_blocks();
+  fs_info.missing_repl_one_blocks = fs->missing_repl_one_blocks();
+  if(fs->has_blocks_in_future()){
+    fs_info.blocks_in_future = fs->blocks_in_future();
+  }
+}
+
 }

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/namenode_operations.h

@@ -20,6 +20,7 @@
 
 #include "rpc/rpc_engine.h"
 #include "hdfspp/statinfo.h"
+#include "hdfspp/fsinfo.h"
 #include "ClientNamenodeProtocol.pb.h"
 #include "ClientNamenodeProtocol.hrpc.inl"
 
@@ -35,6 +36,7 @@ namespace hdfs {
 * Threading model: thread-safe; all operations can be called concurrently
 * Lifetime: owned by a FileSystemImpl
 */
+
 class NameNodeOperations {
 public:
   MEMCHECKED_CLASS(NameNodeOperations);
@@ -56,16 +58,31 @@ public:
   void GetFileInfo(const std::string & path,
       std::function<void(const Status &, const StatInfo &)> handler);
 
+  void GetFsStats(std::function<void(const Status &, const FsInfo &)> handler);
+
   // start_after="" for initial call
   void GetListing(const std::string & path,
         std::function<void(const Status &, std::shared_ptr<std::vector<StatInfo>>&, bool)> handler,
         const std::string & start_after = "");
 
+  void CreateSnapshot(const std::string & path, const std::string & name,
+      std::function<void(const Status &)> handler);
+
+  void DeleteSnapshot(const std::string & path, const std::string & name,
+      std::function<void(const Status &)> handler);
+
+  void AllowSnapshot(const std::string & path,
+      std::function<void(const Status &)> handler);
+
+  void DisallowSnapshot(const std::string & path,
+      std::function<void(const Status &)> handler);
+
   void SetFsEventCallback(fs_event_callback callback);
 
 private:
   static void HdfsFileStatusProtoToStatInfo(hdfs::StatInfo & si, const ::hadoop::hdfs::HdfsFileStatusProto & fs);
   static void DirectoryListingProtoToStatInfo(std::shared_ptr<std::vector<StatInfo>> stat_infos, const ::hadoop::hdfs::DirectoryListingProto & dl);
+  static void GetFsStatsResponseProtoToFsInfo(hdfs::FsInfo & fs_info, const std::shared_ptr<::hadoop::hdfs::GetFsStatsResponseProto> & fs);
 
   ::asio::io_service * io_service_;
   RpcEngine engine_;

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/hdfs_ext_test.cc

@@ -20,7 +20,7 @@
 
 #include "hdfspp_mini_dfs.h"
 #include "hdfspp/hdfs_ext.h"
-
+#include <chrono>
 
 namespace hdfs {
 
@@ -66,6 +66,113 @@ TEST_F(HdfsExtTest, TestGetBlockLocations) {
 }
 
 
+// Writing a file to the filesystem and checking the used space
+TEST_F(HdfsExtTest, TestGetUsed) {
+  using namespace std::chrono;
+
+  HdfsHandle connection = cluster.connect_c();
+  hdfsFS fs = connection.handle();
+  EXPECT_NE(nullptr, fs);
+
+  // File system's used space before writing
+  tOffset used_before_write;
+  EXPECT_GE(used_before_write = hdfsGetUsed(fs), 0);
+
+  // Write to a file
+  tOffset fileSize = 1024;
+  std::string filename = connection.newFile(fileSize);
+
+  //Need to run hdfsGetUsed() in a loop until the refreshInterval
+  //is passed on the filesystem and the used space is updated
+  //Time-out is 3 minutes
+  tOffset used_after_write;
+  tOffset difference;
+  minutes beginTime = duration_cast<minutes>(
+      system_clock::now().time_since_epoch());
+  minutes currentTime;
+  do{
+    EXPECT_GE(used_after_write = hdfsGetUsed(fs), 0);
+    difference = used_after_write - used_before_write;
+    currentTime = duration_cast<minutes>(
+          system_clock::now().time_since_epoch());
+  } while (difference == 0 && currentTime.count() - beginTime.count() < 3);
+
+  //There should be at least fileSize bytes added to the used space
+  EXPECT_GT(difference, fileSize);
+  //There could be additional metadata added to the used space,
+  //but no more than double the fileSize
+  EXPECT_LT(difference, fileSize * 2);
+
+}
+
+
+//Testing allow, disallow, create, and delete snapshot
+TEST_F(HdfsExtTest, TestSnapshotOperations) {
+  HdfsHandle connection = cluster.connect_c();
+  hdfsFS fs = connection.handle();
+  EXPECT_NE(nullptr, fs);
+
+  //argument 'path' is NULL
+  EXPECT_EQ(-1, hdfsAllowSnapshot(fs, nullptr));
+  EXPECT_EQ((int) std::errc::invalid_argument, errno);
+  EXPECT_EQ(-1, hdfsCreateSnapshot(fs, nullptr, "Bad"));
+  EXPECT_EQ((int) std::errc::invalid_argument, errno);
+  EXPECT_EQ(-1, hdfsDeleteSnapshot(fs, nullptr, "Bad"));
+  EXPECT_EQ((int) std::errc::invalid_argument, errno);
+  EXPECT_EQ(-1, hdfsDisallowSnapshot(fs, nullptr));
+  EXPECT_EQ((int) std::errc::invalid_argument, errno);
+
+  //argument 'name' is NULL for deletion
+  EXPECT_EQ(-1, hdfsDeleteSnapshot(fs, "/dir/", nullptr));
+  EXPECT_EQ((int) std::errc::invalid_argument, errno);
+
+  //Path not found
+  std::string path = "/wrong/dir/";
+  EXPECT_EQ(-1, hdfsAllowSnapshot(fs, path.c_str()));
+  EXPECT_EQ((int) std::errc::no_such_file_or_directory, errno);
+  EXPECT_EQ(-1, hdfsCreateSnapshot(fs, path.c_str(), "Bad"));
+  EXPECT_EQ((int) std::errc::no_such_file_or_directory, errno);
+  EXPECT_EQ(-1, hdfsDeleteSnapshot(fs, path.c_str(), "Bad"));
+  EXPECT_EQ((int) std::errc::no_such_file_or_directory, errno);
+  EXPECT_EQ(-1, hdfsDisallowSnapshot(fs, path.c_str()));
+  EXPECT_EQ((int) std::errc::no_such_file_or_directory, errno);
+
+  //Not a directory
+  path = connection.newFile(1024); //1024 byte file
+  EXPECT_EQ(-1, hdfsAllowSnapshot(fs, path.c_str()));
+  EXPECT_EQ((int) std::errc::not_a_directory, errno);
+  EXPECT_EQ(-1, hdfsCreateSnapshot(fs, path.c_str(), "Bad"));
+  EXPECT_EQ((int) std::errc::not_a_directory, errno);
+  EXPECT_EQ(-1, hdfsDeleteSnapshot(fs, path.c_str(), "Bad"));
+  EXPECT_EQ((int) std::errc::not_a_directory, errno);
+  EXPECT_EQ(-1, hdfsDisallowSnapshot(fs, path.c_str()));
+  EXPECT_EQ((int) std::errc::not_a_directory, errno);
+
+  //Not snapshottable directory
+  std::string dirName = connection.newDir();
+  EXPECT_EQ(0, hdfsDisallowSnapshot(fs, dirName.c_str()));
+  EXPECT_EQ(-1, hdfsCreateSnapshot(fs, dirName.c_str(), "Bad"));
+  EXPECT_EQ((int) std::errc::invalid_argument, errno);
+
+  //Verify snapshot created
+  EXPECT_EQ(0, hdfsAllowSnapshot(fs, dirName.c_str()));
+  EXPECT_EQ(0, hdfsCreateSnapshot(fs, dirName.c_str(), "Good"));
+  std::string snapDir = dirName + ".snapshot/";
+  int size;
+  hdfsFileInfo *file_infos;
+  EXPECT_NE(nullptr, file_infos = hdfsListDirectory(fs, snapDir.c_str(), &size));
+  EXPECT_EQ(1, size);
+  EXPECT_STREQ("Good", file_infos[0].mName);
+  hdfsFreeFileInfo(file_infos, 1);
+
+  //Verify snapshot deleted
+  EXPECT_EQ(0, hdfsDeleteSnapshot(fs, dirName.c_str(), "Good"));
+  EXPECT_EQ(nullptr, file_infos = hdfsListDirectory(fs, snapDir.c_str(), &size));
+  EXPECT_EQ(0, size);
+  hdfsFreeFileInfo(file_infos, 0);
+}
+
+
 }
 
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/hdfs_shim.c

@@ -328,11 +328,11 @@ tOffset hdfsGetDefaultBlockSizeAtPath(hdfsFS fs, const char *path) {
 }
 
 tOffset hdfsGetCapacity(hdfsFS fs) {
-  return libhdfs_hdfsGetCapacity(fs->libhdfsRep);
+  return libhdfspp_hdfsGetCapacity(fs->libhdfsppRep);
 }
 
 tOffset hdfsGetUsed(hdfsFS fs) {
-  return libhdfs_hdfsGetUsed(fs->libhdfsRep);
+  return libhdfspp_hdfsGetUsed(fs->libhdfsppRep);
 }
 
 int hdfsChown(hdfsFS fs, const char* path, const char *owner,
@@ -404,3 +404,19 @@ int hdfsGetBlockLocations(hdfsFS fs, const char *path, struct hdfsBlockLocations
 int hdfsFreeBlockLocations(struct hdfsBlockLocations * locations) {
   return libhdfspp_hdfsFreeBlockLocations(locations);
 }
+
+int hdfsCreateSnapshot(hdfsFS fs, const char* path, const char* name) {
+  return libhdfspp_hdfsCreateSnapshot(fs->libhdfsppRep, path, name);
+}
+
+int hdfsDeleteSnapshot(hdfsFS fs, const char* path, const char* name) {
+  return libhdfspp_hdfsDeleteSnapshot(fs->libhdfsppRep, path, name);
+}
+
+int hdfsAllowSnapshot(hdfsFS fs, const char* path) {
+  return libhdfspp_hdfsAllowSnapshot(fs->libhdfsppRep, path);
+}
+
+int hdfsDisallowSnapshot(hdfsFS fs, const char* path) {
+  return libhdfspp_hdfsDisallowSnapshot(fs->libhdfsppRep, path);
+}

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/libhdfs_wrapper_undefs.h

@@ -94,3 +94,7 @@
 #undef hdfsCancel
 #undef hdfsGetBlockLocations
 #undef hdfsFreeBlockLocations
+#undef hdfsCreateSnapshot
+#undef hdfsDeleteSnapshot
+#undef hdfsAllowSnapshot
+#undef hdfsDisallowSnapshot

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/libhdfspp_wrapper_defines.h

@@ -94,3 +94,7 @@
 #define hdfsCancel libhdfspp_hdfsCancel
 #define hdfsGetBlockLocations libhdfspp_hdfsGetBlockLocations
 #define hdfsFreeBlockLocations libhdfspp_hdfsFreeBlockLocations
+#define hdfsCreateSnapshot libhdfspp_hdfsCreateSnapshot
+#define hdfsDeleteSnapshot libhdfspp_hdfsDeleteSnapshot
+#define hdfsAllowSnapshot libhdfspp_hdfsAllowSnapshot
+#define hdfsDisallowSnapshot libhdfspp_hdfsDisallowSnapshot