| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed 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.harmony.luni.internal.net.www.protocol.http; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.net.CacheRequest; |
| |
| /** |
| * An input stream for the body of an HTTP response. |
| * |
| * <p>Since a single socket's input stream may be used to read multiple HTTP |
| * responses from the same server, subclasses shouldn't close the socket stream. |
| * |
| * <p>A side effect of reading an HTTP response is that the response cache |
| * is populated. If the stream is closed early, that cache entry will be |
| * invalidated. |
| */ |
| abstract class AbstractHttpInputStream extends InputStream { |
| protected final InputStream in; |
| protected final HttpURLConnectionImpl httpURLConnection; |
| protected final CacheRequest cacheRequest; |
| protected final OutputStream cacheOut; |
| protected boolean closed; |
| private byte[] skipBuffer; |
| |
| AbstractHttpInputStream(InputStream in, HttpURLConnectionImpl httpURLConnection, |
| CacheRequest cacheRequest) throws IOException { |
| this.in = in; |
| this.httpURLConnection = httpURLConnection; |
| this.cacheRequest = cacheRequest; |
| this.cacheOut = cacheRequest != null ? cacheRequest.getBody() : null; |
| } |
| |
| /** |
| * read() is implemented using read(byte[], int, int) so subclasses only |
| * need to override the latter. |
| */ |
| @Override public final int read() throws IOException { |
| byte[] buffer = new byte[1]; |
| int count = read(buffer, 0, 1); |
| return count == -1 ? -1 : buffer[0] & 0xff; |
| } |
| |
| /** |
| * skip(long) is implemented using read(byte[], int, int) so subclasses |
| * only need to override the latter. |
| */ |
| @Override public final long skip(long n) throws IOException { |
| if (skipBuffer == null) { |
| skipBuffer = new byte[4096]; |
| } |
| long total = 0; |
| while (total < n) { |
| // Calling read() ensures the skipped bytes make it into the response cache. |
| int count = read(skipBuffer, 0, (int) Math.min(n - total, skipBuffer.length)); |
| if (count == -1) { |
| break; |
| } |
| total += count; |
| } |
| return total; |
| } |
| |
| protected final void checkBounds(byte[] buffer, int offset, int count) { |
| if (offset < 0 || offset > buffer.length || count < 0 || buffer.length - offset < count) { |
| throw new ArrayIndexOutOfBoundsException( |
| "offset=" + offset + ", buffer.length=" + buffer.length + ", count=" + count); |
| } |
| } |
| |
| protected final void checkNotClosed() throws IOException { |
| if (closed) { |
| throw new IOException("stream closed"); |
| } |
| } |
| |
| protected final void cacheWrite(byte[] buffer, int offset, int count) throws IOException { |
| if (cacheOut != null) { |
| cacheOut.write(buffer, offset, count); |
| } |
| } |
| |
| /** |
| * Closes the cache entry and makes the socket available for reuse. This |
| * should be invoked when the end of the body has been reached. |
| */ |
| protected final void endOfInput(boolean reuseSocket) throws IOException { |
| if (cacheRequest != null) { |
| cacheOut.close(); |
| } |
| httpURLConnection.releaseSocket(reuseSocket); |
| } |
| |
| /** |
| * Calls abort on the cache entry and disconnects the socket. This |
| * should be invoked when the connection is closed unexpectedly to |
| * invalidate the cache entry and to prevent the HTTP connection from |
| * being reused. HTTP messages are sent in serial so whenever a message |
| * cannot be read to completion, subsequent messages cannot be read |
| * either and the connection must be discarded. |
| * |
| * <p>An earlier implementation skipped the remaining bytes, but this |
| * requires that the entire transfer be completed. If the intention was |
| * to cancel the transfer, closing the connection is the only solution. |
| */ |
| protected final void unexpectedEndOfInput() { |
| if (cacheRequest != null) { |
| cacheRequest.abort(); |
| } |
| httpURLConnection.releaseSocket(false); |
| } |
| } |