org.apache.synapse.commons.util.TemporaryData Maven / Gradle / Ivy
/*
* 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.synapse.commons.util;
import org.apache.commons.io.IOUtils;
import org.apache.commons.io.FileUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.*;
/**
* Class representing some temporary data in the form of a byte stream.
*
* Data is stored by writing to the output stream obtained using
* {@link #getOutputStream()}. It can then be read back using
* the input stream obtained from {@link #getInputStream()}.
* The data is first stored into a fixed size buffer. Once this
* buffer overflows, it is transferred to a temporary file. The buffer
* is divided into a given number of fixed size chunks that are allocated
* on demand. Since a temporary file may be created it is mandatory to
* call {@link #release()} to discard the temporary data.
*
* @deprecated this class is deprecated and will be removed from the next release,
* please use the {@link org.apache.axiom.util.blob.OverflowBlob} from axiom instead
*/
@Deprecated
public class TemporaryData {
private static final Log log = LogFactory.getLog(TemporaryData.class);
class OutputStreamImpl extends OutputStream {
private FileOutputStream fileOutputStream;
public void write(byte[] b, int off, int len) throws IOException {
if (fileOutputStream != null) {
fileOutputStream.write(b, off, len);
} else if (len > (chunks.length-chunkIndex)*chunkSize - chunkOffset) {
// The buffer will overflow. Switch to a temporary file.
fileOutputStream = switchToTempFile();
// Write the new data to the temporary file.
fileOutputStream.write(b, off, len);
} else {
// The data will fit into the buffer.
while (len > 0) {
byte[] chunk = getCurrentChunk();
// Determine number of bytes that can be copied to the current chunk.
int c = Math.min(len, chunkSize-chunkOffset);
// Copy data to the chunk.
System.arraycopy(b, off, chunk, chunkOffset, c);
// Update variables.
len -= c;
off += c;
chunkOffset += c;
if (chunkOffset == chunkSize) {
chunkIndex++;
chunkOffset = 0;
}
}
}
}
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
public void write(int b) throws IOException {
write(new byte[] { (byte)b }, 0, 1);
}
public void flush() throws IOException {
if (fileOutputStream != null) {
fileOutputStream.flush();
}
}
public void close() throws IOException {
if (fileOutputStream != null) {
fileOutputStream.close();
}
}
}
class InputStreamImpl extends InputStream {
private int currentChunkIndex;
private int currentChunkOffset;
private int markChunkIndex;
private int markChunkOffset;
public int available() throws IOException {
return (chunkIndex-currentChunkIndex)*chunkSize + chunkOffset - currentChunkOffset;
}
public int read(byte[] b, int off, int len) throws IOException {
if (len == 0) {
return 0;
}
int read = 0;
while (len > 0 && !(currentChunkIndex == chunkIndex
&& currentChunkOffset == chunkOffset)) {
int c;
if (currentChunkIndex == chunkIndex) {
// The current chunk is the last one => take into account the offset
c = Math.min(len, chunkOffset-currentChunkOffset);
} else {
c = Math.min(len, chunkSize-currentChunkOffset);
}
// Copy the data.
System.arraycopy(chunks[currentChunkIndex], currentChunkOffset, b, off, c);
// Update variables
len -= c;
off += c;
currentChunkOffset += c;
read += c;
if (currentChunkOffset == chunkSize) {
currentChunkIndex++;
currentChunkOffset = 0;
}
}
if (read == 0) {
// We didn't read anything (and the len argument was not 0) => we reached the end of the buffer.
return -1;
} else {
return read;
}
}
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
public int read() throws IOException {
byte[] b = new byte[1];
return read(b) == -1 ? -1 : (int)b[0] & 0xFF;
}
public boolean markSupported() {
return true;
}
public void mark(int readlimit) {
markChunkIndex = currentChunkIndex;
markChunkOffset = currentChunkOffset;
}
public void reset() throws IOException {
currentChunkIndex = markChunkIndex;
currentChunkOffset = markChunkOffset;
}
public long skip(long n) throws IOException {
int available = available();
int c = n < available ? (int)n : available;
int newOffset = currentChunkOffset + c;
int chunkDelta = newOffset/chunkSize;
currentChunkIndex += chunkDelta;
currentChunkOffset = newOffset - (chunkDelta*chunkSize);
return c;
}
public void close() throws IOException {
}
}
/**
* Size of the chunks that will be allocated in the buffer.
*/
final int chunkSize;
/**
* The prefix to be used in generating the name of the temporary file.
*/
final String tempPrefix;
/**
* The suffix to be used in generating the name of the temporary file.
*/
final String tempSuffix;
/**
* Array of byte[] representing the chunks of the buffer.
* A chunk is only allocated when the first byte is written to it.
* This attribute is set to null when the buffer overflows and
* is written out to a temporary file.
*/
byte[][] chunks;
/**
* Index of the chunk the next byte will be written to.
*/
int chunkIndex;
/**
* Offset into the chunk where the next byte will be written.
*/
int chunkOffset;
/**
* The handle of the temporary file. This is only set when the memory buffer
* overflows and is written out to a temporary file.
*/
File temporaryFile;
public TemporaryData(int numberOfChunks, int chunkSize, String tempPrefix, String tempSuffix) {
this.chunkSize = chunkSize;
this.tempPrefix = tempPrefix;
this.tempSuffix = tempSuffix;
chunks = new byte[numberOfChunks][];
}
/**
* Get the current chunk to write to, allocating it if necessary.
*
* @return the current chunk to write to (never null)
*/
byte[] getCurrentChunk() {
if (chunkOffset == 0) {
// We will write the first byte to the current chunk. Allocate it.
byte[] chunk = new byte[chunkSize];
chunks[chunkIndex] = chunk;
return chunk;
} else {
// The chunk has already been allocated.
return chunks[chunkIndex];
}
}
/**
* Create a temporary file and write the existing in memory data to it.
*
* @return an open FileOutputStream to the temporary file
* @throws IOException in case of an error in switching to the temp file
*/
FileOutputStream switchToTempFile() throws IOException {
temporaryFile = File.createTempFile(tempPrefix, tempSuffix);
if (log.isDebugEnabled()) {
log.debug("Using temporary file " + temporaryFile);
}
temporaryFile.deleteOnExit();
FileOutputStream fileOutputStream = new FileOutputStream(temporaryFile);
// Write the buffer to the temporary file.
for (int i=0; i 0) {
fileOutputStream.write(chunks[chunkIndex], 0, chunkOffset);
}
// Release references to the buffer so that it can be garbage collected.
chunks = null;
return fileOutputStream;
}
public OutputStream getOutputStream() {
return new OutputStreamImpl();
}
/**
* Fill this object with data read from a given InputStream.
*
* A call tmp.readFrom(in) has the same effect as the
* following code:
*
* OutputStream out = tmp.getOutputStream();
* IOUtils.copy(in, out);
* out.close();
*
* However it does so in a more efficient way.
*
* @param in An InputStream to read data from. This method will not
* close the stream.
* @throws IOException in case of an error in reading from InputStream
*/
public void readFrom(InputStream in) throws IOException {
while (true) {
int c = in.read(getCurrentChunk(), chunkOffset, chunkSize-chunkOffset);
if (c == -1) {
break;
}
chunkOffset += c;
if (chunkOffset == chunkSize) {
chunkIndex++;
chunkOffset = 0;
if (chunkIndex == chunks.length) {
FileOutputStream fileOutputStream = switchToTempFile();
IOUtils.copy(in, fileOutputStream);
fileOutputStream.close();
break;
}
}
}
}
public InputStream getInputStream() throws IOException {
if (temporaryFile != null) {
return new FileInputStream(temporaryFile);
} else {
return new InputStreamImpl();
}
}
/**
* Write the data to a given output stream.
*
* @param out The output stream to write the data to. This method will
* not close the stream.
* @throws IOException in case of an error in writing to the OutputStream
*/
public void writeTo(OutputStream out) throws IOException {
if (temporaryFile != null) {
FileInputStream in = new FileInputStream(temporaryFile);
try {
IOUtils.copy(in, out);
} finally {
in.close();
}
} else {
for (int i=0; i 0) {
out.write(chunks[chunkIndex], 0, chunkOffset);
}
}
}
public long getLength() {
if (temporaryFile != null) {
return temporaryFile.length();
} else {
return chunkIndex*chunkSize + chunkOffset;
}
}
@SuppressWarnings({"ResultOfMethodCallIgnored"})
public void release() {
if (temporaryFile != null) {
if (log.isDebugEnabled()) {
log.debug("Deleting temporary file " + temporaryFile);
}
FileUtils.deleteQuietly(temporaryFile);
temporaryFile = null;
}
}
@SuppressWarnings({"FinalizeDoesntCallSuperFinalize", "ResultOfMethodCallIgnored"})
@Override
protected void finalize() throws Throwable {
if (temporaryFile != null) {
log.warn("Cleaning up unreleased temporary file " + temporaryFile);
FileUtils.deleteQuietly(temporaryFile);
}
}
}