nl.topicus.jdbc.shaded.io.netty.handler.stream.ChunkedStream Maven / Gradle / Ivy
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/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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 nl.topicus.jdbc.shaded.io.netty.handler.stream;
import nl.topicus.jdbc.shaded.io.netty.buffer.ByteBuf;
import nl.topicus.jdbc.shaded.io.netty.buffer.ByteBufAllocator;
import nl.topicus.jdbc.shaded.io.netty.channel.ChannelHandlerContext;
import java.io.InputStream;
import java.io.PushbackInputStream;
/**
* A {@link ChunkedInput} that fetches data from an {@link InputStream} chunk by
* chunk.
*
* Please note that the {@link InputStream} instance that feeds data into
* {@link ChunkedStream} must implement {@link InputStream#available()} as
* accurately as possible, rather than using the default implementation.
* Otherwise, {@link ChunkedStream} will generate many too small chunks or
* block unnecessarily often.
*/
public class ChunkedStream implements ChunkedInput {
static final int DEFAULT_CHUNK_SIZE = 8192;
private final PushbackInputStream in;
private final int chunkSize;
private long offset;
private boolean closed;
/**
* Creates a new instance that fetches data from the specified stream.
*/
public ChunkedStream(InputStream in) {
this(in, DEFAULT_CHUNK_SIZE);
}
/**
* Creates a new instance that fetches data from the specified stream.
*
* @param chunkSize the number of bytes to fetch on each
* {@link #readChunk(ChannelHandlerContext)} call
*/
public ChunkedStream(InputStream in, int chunkSize) {
if (in == null) {
throw new NullPointerException("in");
}
if (chunkSize <= 0) {
throw new IllegalArgumentException(
"chunkSize: " + chunkSize +
" (expected: a positive integer)");
}
if (in instanceof PushbackInputStream) {
this.in = (PushbackInputStream) in;
} else {
this.in = new PushbackInputStream(in);
}
this.chunkSize = chunkSize;
}
/**
* Returns the number of transferred bytes.
*/
public long transferredBytes() {
return offset;
}
@Override
public boolean isEndOfInput() throws Exception {
if (closed) {
return true;
}
int b = in.read();
if (b < 0) {
return true;
} else {
in.unread(b);
return false;
}
}
@Override
public void close() throws Exception {
closed = true;
in.close();
}
@Deprecated
@Override
public ByteBuf readChunk(ChannelHandlerContext ctx) throws Exception {
return readChunk(ctx.alloc());
}
@Override
public ByteBuf readChunk(ByteBufAllocator allocator) throws Exception {
if (isEndOfInput()) {
return null;
}
final int availableBytes = in.available();
final int chunkSize;
if (availableBytes <= 0) {
chunkSize = this.chunkSize;
} else {
chunkSize = Math.min(this.chunkSize, in.available());
}
boolean release = true;
ByteBuf buffer = allocator.buffer(chunkSize);
try {
// transfer to buffer
offset += buffer.writeBytes(in, chunkSize);
release = false;
return buffer;
} finally {
if (release) {
buffer.release();
}
}
}
@Override
public long length() {
return -1;
}
@Override
public long progress() {
return offset;
}
}