YARN-7250. Update Shared cache client api to use URLs.

(cherry picked from commit c114da5e64d14b1d9e614081c4171ea0391cb1aa)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/SharedCacheClient.java

@@ -27,6 +27,7 @@ import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.service.AbstractService;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.URL;
 import org.apache.hadoop.yarn.client.api.impl.SharedCacheClientImpl;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 
@@ -58,34 +59,25 @@ public abstract class SharedCacheClient extends AbstractService {
    *
    * <p>
    * The <code>SharedCacheManager</code> responds with whether or not the
-   * resource exists in the cache. If the resource exists, a <code>Path</code>
-   * to the resource in the shared cache is returned. If the resource does not
+   * resource exists in the cache. If the resource exists, a <code>URL</code> to
+   * the resource in the shared cache is returned. If the resource does not
    * exist, null is returned instead.
    * </p>
    *
    * <p>
-   * Once a path has been returned for a resource, that path is safe to use for
+   * Once a URL has been returned for a resource, that URL is safe to use for
    * the lifetime of the application that corresponds to the provided
    * ApplicationId.
    * </p>
    *
-   * <p>
-   * Additionally, a name for the resource should be specified. A fragment will
-   * be added to the path with the desired name if the desired name is different
-   * than the name of the provided path from the shared cache. This ensures that
-   * if the returned path is used to create a LocalResource, then the symlink
-   * created during YARN localization will match the name specified.
-   * </p>
-   *
    * @param applicationId ApplicationId of the application using the resource
    * @param resourceKey the key (i.e. checksum) that identifies the resource
-   * @param resourceName the desired name of the resource
-   * @return Path to the resource, or null if it does not exist
+   * @return URL to the resource, or null if it does not exist
    */
   @Public
   @Unstable
-  public abstract Path use(ApplicationId applicationId, String resourceKey,
-      String resourceName) throws YarnException;
+  public abstract URL use(ApplicationId applicationId, String resourceKey)
+      throws YarnException;
 
   /**
    * <p>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/impl/SharedCacheClientImpl.java

@@ -21,8 +21,6 @@ package org.apache.hadoop.yarn.client.api.impl;
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
-import java.net.URI;
-import java.net.URISyntaxException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -38,6 +36,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReleaseSharedCacheResourceRequ
 import org.apache.hadoop.yarn.api.protocolrecords.UseSharedCacheResourceRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.UseSharedCacheResourceResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.URL;
 import org.apache.hadoop.yarn.client.api.SharedCacheClient;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
@@ -113,8 +112,8 @@ public class SharedCacheClientImpl extends SharedCacheClient {
   }
 
   @Override
-  public Path use(ApplicationId applicationId, String resourceKey,
-      String resourceName) throws YarnException {
+  public URL use(ApplicationId applicationId, String resourceKey)
+      throws YarnException {
     Path resourcePath = null;
     UseSharedCacheResourceRequest request = Records.newRecord(
         UseSharedCacheResourceRequest.class);
@@ -132,31 +131,12 @@ public class SharedCacheClientImpl extends SharedCacheClient {
       throw new YarnException(e);
     }
     if (resourcePath != null) {
-      if (resourcePath.getName().equals(resourceName)) {
-        // The preferred name is the same as the name of the item in the cache,
-        // so we skip generating the fragment to save space in the MRconfig.
-        return resourcePath;
-      } else {
-        // We are using the shared cache, and a preferred name has been
-        // specified that is different than the name of the resource in the
-        // shared cache. We need to set the fragment portion of the URI to
-        // preserve the desired name.
-        URI pathURI = resourcePath.toUri();
-        try {
-          // We assume that there is no existing fragment in the URI since the
-          // shared cache manager does not use fragments.
-          pathURI =
-              new URI(pathURI.getScheme(), pathURI.getSchemeSpecificPart(),
-                  resourceName);
-          resourcePath = new Path(pathURI);
-        } catch (URISyntaxException e) {
-          throw new YarnException(
-              "Could not create a new URI due to syntax errors: "
-                  + pathURI.toString(), e);
-        }
-      }
+      URL pathURL = URL.fromPath(resourcePath);
+      return pathURL;
+    } else {
+      // The resource was not in the cache.
+      return null;
     }
-    return resourcePath;
   }
 
   @Override

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/api/impl/TestSharedCacheClientImpl.java

@@ -27,7 +27,6 @@ import static org.mockito.Mockito.when;
 import java.io.DataOutputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.net.URI;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -40,6 +39,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.UseSharedCacheResourceRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.UseSharedCacheResourceResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.UseSharedCacheResourceResponsePBImpl;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.URL;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.junit.After;
 import org.junit.AfterClass;
@@ -114,36 +114,21 @@ public class TestSharedCacheClientImpl {
     response.setPath(null);
     when(cProtocol.use(isA(UseSharedCacheResourceRequest.class))).thenReturn(
         response);
-    Path newPath = client.use(mock(ApplicationId.class), "key", null);
-    assertNull("The path is not null!", newPath);
+    URL newURL = client.use(mock(ApplicationId.class), "key");
+    assertNull("The path is not null!", newURL);
   }
 
   @Test
-  public void testUseWithResourceName() throws Exception {
+  public void testUseCacheHit() throws Exception {
     Path file = new Path("viewfs://test/path");
-    URI useUri = new URI("viewfs://test/path#linkName");
-    Path usePath = new Path(useUri);
+    URL useUrl = URL.fromPath(new Path("viewfs://test/path"));
     UseSharedCacheResourceResponse response =
         new UseSharedCacheResourceResponsePBImpl();
     response.setPath(file.toString());
     when(cProtocol.use(isA(UseSharedCacheResourceRequest.class))).thenReturn(
         response);
-    Path newPath = client.use(mock(ApplicationId.class), "key", "linkName");
-    assertEquals("The paths are not equal!", usePath, newPath);
-  }
-
-  @Test
-  public void testUseWithSameResourceName() throws Exception {
-    Path file = new Path("viewfs://test/path");
-    URI useUri = new URI("viewfs://test/path");
-    Path usePath = new Path(useUri);
-    UseSharedCacheResourceResponse response =
-        new UseSharedCacheResourceResponsePBImpl();
-    response.setPath(file.toString());
-    when(cProtocol.use(isA(UseSharedCacheResourceRequest.class))).thenReturn(
-        response);
-    Path newPath = client.use(mock(ApplicationId.class), "key", "path");
-    assertEquals("The paths are not equal!", usePath, newPath);
+    URL newURL = client.use(mock(ApplicationId.class), "key");
+    assertEquals("The paths are not equal!", useUrl, newURL);
   }
 
   @Test(expected = YarnException.class)
@@ -151,7 +136,7 @@ public class TestSharedCacheClientImpl {
     String message = "Mock IOExcepiton!";
     when(cProtocol.use(isA(UseSharedCacheResourceRequest.class))).thenThrow(
         new IOException(message));
-    client.use(mock(ApplicationId.class), "key", null);
+    client.use(mock(ApplicationId.class), "key");
   }
 
   @Test