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/*
* Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.
* According to cos feature, we modify some class，comment, field name, etc.
*/
package com.qcloud.cos.model;
import java.io.IOException;
import java.io.InputStream;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.conn.EofSensorInputStream;
import com.qcloud.cos.internal.SdkFilterInputStream;
import com.qcloud.cos.utils.IOUtils;
/**
* Input stream representing the content of an {@link COSObject}. In addition to
* the methods supplied by the {@link InputStream} class,
* {@link COSObjectInputStream} supplies the abort() method, which will terminate
* an HTTP connection to the COS object.
*/
public class COSObjectInputStream extends SdkFilterInputStream {
private final HttpRequestBase httpRequest;
private boolean eof;
public COSObjectInputStream(
InputStream in,
HttpRequestBase httpRequest) {
super(in);
this.httpRequest = httpRequest;
}
/**
* {@inheritDoc}
*
* Aborts the underlying http request without reading any more data and
* closes the stream.
*
* By default Apache {@link HttpClient} tries to reuse http connections by
* reading to the end of an attached input stream on
* {@link InputStream#close()}. This is efficient from a socket pool
* management perspective, but for objects with large payloads can incur
* significant overhead while bytes are read from COS and discarded. It's up
* to clients to decide when to take the performance hit implicit in not
* reusing an http connection in order to not read unnecessary information
* from COS.
*
* @see EofSensorInputStream
*/
@Override
public void abort() {
doAbort();
}
/**
* To allow customers to override abort to just close. We can think about exposing this method
* as protected to allow customers to completely prevent the abort behavior if there is a need
*/
private void doAbort() {
if (httpRequest != null) {
httpRequest.abort();
}
IOUtils.closeQuietly(in, null);
}
/**
* Returns the http request from which this input stream is derived.
*/
public HttpRequestBase getHttpRequest() {
return httpRequest;
}
/**
* Returns super.available() if the value is not zero or else always returns
* 1. This is necessary to get around a GZIPInputStream bug which would
* mis-behave in some edge cases upon zero returned from available(),
* causing file truncation.
*
* http://bugs.java.com/bugdatabase/view_bug.do?bug_id=7036144
*
* Reference TT: 0034867351
*/
@Override
public int available() throws IOException {
int estimate = super.available();
return estimate == 0 ? 1 : estimate;
}
/**
* {@inheritDoc}
*/
@Override
public int read() throws IOException {
int value = super.read();
if (value == -1) {
eof = true;
}
return value;
}
/**
* {@inheritDoc}
*/
@Override
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
/**
* {@inheritDoc}
*/
@Override
public int read(byte[] b, int off, int len) throws IOException {
int value = super.read(b, off, len);
if (value == -1) {
eof = true;
}
return value;
}
/**
* {@inheritDoc}
*/
@Override
public void reset() throws IOException {
super.reset();
eof = false;
}
/**
* {@inheritDoc}
*
* Delegate to {@link COSObjectInputStream#abort()} if there is data remaining in the stream. If the stream has been
* read completely, with no data remaining, safely close the stream.
*
* @see {@link COSObjectInputStream#abort()}
*/
@Override
public void close() throws IOException {
if (eof) {
super.close();
httpRequest.releaseConnection();
} else {
doAbort();
}
}
}