| /* |
| * 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. |
| */ |
| |
| package org.apache.hadoop.fs.swift.http; |
| |
| import org.apache.hadoop.fs.swift.exceptions.SwiftConnectionClosedException; |
| import org.apache.hadoop.fs.swift.util.SwiftUtils; |
| import org.apache.http.HttpResponse; |
| import org.apache.http.client.methods.HttpRequestBase; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.net.URI; |
| |
| /** |
| * This replaces the input stream release class from JetS3t and AWS; |
| * # Failures in the constructor are relayed up instead of simply logged. |
| * # it is set up to be more robust at teardown |
| * # release logic is thread safe |
| * Note that the thread safety of the inner stream contains no thread |
| * safety guarantees -this stream is not to be read across streams. |
| * The thread safety logic here is to ensure that even if somebody ignores |
| * that rule, the release code does not get entered twice -and that |
| * any release in one thread is picked up by read operations in all others. |
| */ |
| public class HttpInputStreamWithRelease extends InputStream { |
| |
| private static final Logger LOG = |
| LoggerFactory.getLogger(HttpInputStreamWithRelease.class); |
| private final URI uri; |
| private HttpRequestBase req; |
| private HttpResponse resp; |
| //flag to say the stream is released -volatile so that read operations |
| //pick it up even while unsynchronized. |
| private volatile boolean released; |
| //volatile flag to verify that data is consumed. |
| private volatile boolean dataConsumed; |
| private InputStream inStream; |
| /** |
| * In debug builds, this is filled in with the construction-time |
| * stack, which is then included in logs from the finalize(), method. |
| */ |
| private final Exception constructionStack; |
| |
| /** |
| * Why the stream is closed |
| */ |
| private String reasonClosed = "unopened"; |
| |
| public HttpInputStreamWithRelease(URI uri, HttpRequestBase req, |
| HttpResponse resp) throws IOException { |
| this.uri = uri; |
| this.req = req; |
| this.resp = resp; |
| constructionStack = LOG.isDebugEnabled() ? new Exception("stack") : null; |
| if (req == null) { |
| throw new IllegalArgumentException("Null 'request' parameter "); |
| } |
| try { |
| inStream = resp.getEntity().getContent(); |
| } catch (IOException e) { |
| inStream = new ByteArrayInputStream(new byte[]{}); |
| throw releaseAndRethrow("getResponseBodyAsStream() in constructor -" + e, e); |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| release("close()", null); |
| } |
| |
| /** |
| * Release logic |
| * @param reason reason for release (used in debug messages) |
| * @param ex exception that is a cause -null for non-exceptional releases |
| * @return true if the release took place here |
| * @throws IOException if the abort or close operations failed. |
| */ |
| private synchronized boolean release(String reason, Exception ex) throws |
| IOException { |
| if (!released) { |
| reasonClosed = reason; |
| try { |
| LOG.debug("Releasing connection to {}: {}", uri, reason, ex); |
| if (req != null) { |
| if (!dataConsumed) { |
| req.abort(); |
| } |
| req.releaseConnection(); |
| } |
| if (inStream != null) { |
| //this guard may seem un-needed, but a stack trace seen |
| //on the JetS3t predecessor implied that it |
| //is useful |
| inStream.close(); |
| } |
| return true; |
| } finally { |
| //if something went wrong here, we do not want the release() operation |
| //to try and do anything in advance. |
| released = true; |
| dataConsumed = true; |
| } |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * Release the method, using the exception as a cause |
| * @param operation operation that failed |
| * @param ex the exception which triggered it. |
| * @return the exception to throw |
| */ |
| private IOException releaseAndRethrow(String operation, IOException ex) { |
| try { |
| release(operation, ex); |
| } catch (IOException ioe) { |
| LOG.debug("Exception during release: {}", operation, ioe); |
| //make this the exception if there was none before |
| if (ex == null) { |
| ex = ioe; |
| } |
| } |
| return ex; |
| } |
| |
| /** |
| * Assume that the connection is not released: throws an exception if it is |
| * @throws SwiftConnectionClosedException |
| */ |
| private synchronized void assumeNotReleased() throws SwiftConnectionClosedException { |
| if (released || inStream == null) { |
| throw new SwiftConnectionClosedException(reasonClosed); |
| } |
| } |
| |
| @Override |
| public int available() throws IOException { |
| assumeNotReleased(); |
| try { |
| return inStream.available(); |
| } catch (IOException e) { |
| throw releaseAndRethrow("available() failed -" + e, e); |
| } |
| } |
| |
| @Override |
| public int read() throws IOException { |
| assumeNotReleased(); |
| int read = 0; |
| try { |
| read = inStream.read(); |
| } catch (EOFException e) { |
| LOG.debug("EOF exception", e); |
| read = -1; |
| } catch (IOException e) { |
| throw releaseAndRethrow("read()", e); |
| } |
| if (read < 0) { |
| dataConsumed = true; |
| release("read() -all data consumed", null); |
| } |
| return read; |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| SwiftUtils.validateReadArgs(b, off, len); |
| if (len == 0) { |
| return 0; |
| } |
| //if the stream is already closed, then report an exception. |
| assumeNotReleased(); |
| //now read in a buffer, reacting differently to different operations |
| int read; |
| try { |
| read = inStream.read(b, off, len); |
| } catch (EOFException e) { |
| LOG.debug("EOF exception", e); |
| read = -1; |
| } catch (IOException e) { |
| throw releaseAndRethrow("read(b, off, " + len + ")", e); |
| } |
| if (read < 0) { |
| dataConsumed = true; |
| release("read() -all data consumed", null); |
| } |
| return read; |
| } |
| |
| /** |
| * Finalizer does release the stream, but also logs at WARN level |
| * including the URI at fault |
| */ |
| @Override |
| protected void finalize() { |
| try { |
| if (release("finalize()", constructionStack)) { |
| LOG.warn("input stream of {}" + |
| " not closed properly -cleaned up in finalize()", uri); |
| } |
| } catch (Exception e) { |
| //swallow anything that failed here |
| LOG.warn("Exception while releasing {} in finalizer", uri, e); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "HttpInputStreamWithRelease working with " + uri |
| +" released=" + released |
| +" dataConsumed=" + dataConsumed; |
| } |
| } |