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snappy-java: A fast compression/decompression library
/*--------------------------------------------------------------------------
* Copyright 2011 Taro L. Saito
*
* 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.
*--------------------------------------------------------------------------*/
//--------------------------------------
// snappy-java Project
//
// Snappy.java
// Since: 2011/03/29
//
// $URL$
// $Author$
//--------------------------------------
package org.xerial.snappy;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.Properties;
/**
* Snappy API for data compression/decompression
*
* Note: if the native libraries cannot be loaded, an ExceptionInInitializerError
* will be thrown at first use of this class.
*
* @author Taro L. Saito
*/
public class Snappy
{
static {
try {
impl = SnappyLoader.loadSnappyApi();
}
catch (Exception e) {
throw new ExceptionInInitializerError(e);
}
}
/**
* An instance of SnappyNative
*/
private static SnappyNative impl;
/**
* Clean up a temporary file (native lib) generated by snappy-java.
* General users do not need to call this method, since the native library extracted in snappy-java
* is deleted upon JVM termination (vie deleteOnExit()).
* This method is useful when using a J2EE container, which will restart servlet containers multiple times without
* restarting JVM.
*/
public static void cleanUp()
{
SnappyLoader.cleanUpExtractedNativeLib();
SnappyLoader.setSnappyApi(null);
}
/**
* Copy bytes from source to destination
*
* @param src pointer to the source array
* @param offset byte offset in the source array
* @param byteLength the number of bytes to copy
* @param dest pointer to the destination array
* @param dest_offset byte offset in the destination array
* @throws IOException
*/
public static void arrayCopy(Object src, int offset, int byteLength, Object dest, int dest_offset)
throws IOException
{
impl.arrayCopy(src, offset, byteLength, dest, dest_offset);
}
/**
* High-level API for compressing the input byte array. This method performs
* array copy to generate the result. If you want to reduce the memory copy
* cost, use {@link #compress(byte[], int, int, byte[], int)} or
* {@link #compress(ByteBuffer, ByteBuffer)}.
*
* @param input the input data
* @return the compressed byte array
* @throws IOException
*/
public static byte[] compress(byte[] input)
throws IOException
{
return rawCompress(input, input.length);
}
/**
* Compress the input buffer content in [inputOffset,
* ...inputOffset+inputLength) then output to the specified output buffer.
*
* @param input
* @param inputOffset
* @param inputLength
* @param output
* @param outputOffset
* @return byte size of the compressed data
* @throws IOException when failed to access the input/output buffer
*/
public static int compress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset)
throws IOException
{
return rawCompress(input, inputOffset, inputLength, output, outputOffset);
}
/**
* Compress the content in the given input buffer. After the compression,
* you can retrieve the compressed data from the output buffer [pos() ...
* limit()) (compressed data size = limit() - pos() = remaining())
*
* @param uncompressed buffer[pos() ... limit()) containing the input data
* @param compressed output of the compressed data. Uses range [pos()..].
* @return byte size of the compressed data.
* @throws SnappyError when the input is not a direct buffer
*/
public static int compress(ByteBuffer uncompressed, ByteBuffer compressed)
throws IOException
{
if (!uncompressed.isDirect()) {
throw new SnappyError(SnappyErrorCode.NOT_A_DIRECT_BUFFER, "input is not a direct buffer");
}
if (!compressed.isDirect()) {
throw new SnappyError(SnappyErrorCode.NOT_A_DIRECT_BUFFER, "destination is not a direct buffer");
}
// input: uncompressed[pos(), limit())
// output: compressed
int uPos = uncompressed.position();
int uLen = uncompressed.remaining();
int compressedSize = impl.rawCompress(uncompressed, uPos, uLen, compressed,
compressed.position());
// pos limit
// [ ......BBBBBBB.........]
compressed.limit(compressed.position() + compressedSize);
return compressedSize;
}
/**
* Compress the input char array
*
* @param input
* @return the compressed data
*/
public static byte[] compress(char[] input)
throws IOException
{
return rawCompress(input, input.length * 2); // char uses 2 bytes
}
/**
* Compress the input double array
*
* @param input
* @return the compressed data
*/
public static byte[] compress(double[] input)
throws IOException
{
return rawCompress(input, input.length * 8); // double uses 8 bytes
}
/**
* Compress the input float array
*
* @param input
* @return the compressed data
*/
public static byte[] compress(float[] input)
throws IOException
{
return rawCompress(input, input.length * 4); // float uses 4 bytes
}
/**
* Compress the input int array
*
* @param input
* @return the compressed data
*/
public static byte[] compress(int[] input)
throws IOException
{
return rawCompress(input, input.length * 4); // int uses 4 bytes
}
/**
* Compress the input long array
*
* @param input
* @return the compressed data
*/
public static byte[] compress(long[] input)
throws IOException
{
return rawCompress(input, input.length * 8); // long uses 8 bytes
}
/**
* Compress the input short array
*
* @param input
* @return the compressed data
*/
public static byte[] compress(short[] input)
throws IOException
{
return rawCompress(input, input.length * 2); // short uses 2 bytes
}
/**
* Compress the input String
*
* @param s
* @return the compressed data
* @throws IOException
*/
public static byte[] compress(String s)
throws IOException
{
try {
return compress(s, "UTF-8");
}
catch (UnsupportedEncodingException e) {
throw new IllegalStateException("UTF-8 encoder is not found");
}
}
/**
* Compress the input string using the given encoding
*
* @param s
* @param encoding
* @return the compressed data
* @throws UnsupportedEncodingException
* @throws IOException
*/
public static byte[] compress(String s, String encoding)
throws UnsupportedEncodingException, IOException
{
byte[] data = s.getBytes(encoding);
return compress(data);
}
/**
* Compress the input string using the given encoding
*
* @param s
* @param encoding
* @return the compressed data
* @throws UnsupportedEncodingException
* @throws IOException
*/
public static byte[] compress(String s, Charset encoding)
throws IOException
{
byte[] data = s.getBytes(encoding);
return compress(data);
}
/**
* Get the native library version of the snappy
*
* @return native library version
*/
public static String getNativeLibraryVersion()
{
URL versionFile = SnappyLoader.class.getResource("/org/xerial/snappy/VERSION");
String version = "unknown";
try {
if (versionFile != null) {
InputStream in = null;
try {
Properties versionData = new Properties();
in = versionFile.openStream();
versionData.load(in);
version = versionData.getProperty("version", version);
if (version.equals("unknown")) {
version = versionData.getProperty("SNAPPY_VERSION", version);
}
version = version.trim().replaceAll("[^0-9\\.]", "");
}
finally {
if(in != null) {
in.close();
}
}
}
}
catch (IOException e) {
e.printStackTrace();
}
return version;
}
/**
* Returns true iff the contents of compressed buffer [offset,
* offset+length) can be uncompressed successfully. Does not return the
* uncompressed data. Takes time proportional to the input length, but is
* usually at least a factor of four faster than actual decompression.
*/
public static boolean isValidCompressedBuffer(byte[] input, int offset, int length)
throws IOException
{
if (input == null) {
throw new NullPointerException("input is null");
}
return impl.isValidCompressedBuffer(input, offset, length);
}
/**
* Returns true iff the contents of compressed buffer [offset,
* offset+length) can be uncompressed successfully. Does not return the
* uncompressed data. Takes time proportional to the input length, but is
* usually at least a factor of four faster than actual decompression.
*/
public static boolean isValidCompressedBuffer(byte[] input)
throws IOException
{
return isValidCompressedBuffer(input, 0, input.length);
}
/**
* Returns true iff the contents of compressed buffer [pos() ... limit())
* can be uncompressed successfully. Does not return the uncompressed data.
* Takes time proportional to the input length, but is usually at least a
* factor of four faster than actual decompression.
*/
public static boolean isValidCompressedBuffer(ByteBuffer compressed)
throws IOException
{
return impl.isValidCompressedBuffer(compressed, compressed.position(),
compressed.remaining());
}
/**
* Returns true iff the contents of compressed buffer [offset,
* offset+length) can be uncompressed successfully. Does not return the
* uncompressed data. Takes time proportional to the input length, but is
* usually at least a factor of four faster than actual decompression.
*/
public static boolean isValidCompressedBuffer(long inputAddr, long offset, long length)
throws IOException
{
return impl.isValidCompressedBuffer(inputAddr, offset, length);
}
/**
* Get the maximum byte size needed for compressing data of the given byte
* size.
*
* @param byteSize byte size of the data to compress
* @return maximum byte size of the compressed data
*/
public static int maxCompressedLength(int byteSize)
{
return impl.maxCompressedLength(byteSize);
}
/**
* Zero-copy compress using memory addresses.
*
* @param inputAddr input memory address
* @param inputSize input byte size
* @param destAddr destination address of the compressed data
* @return the compressed data size
* @throws IOException
*/
public static long rawCompress(long inputAddr, long inputSize, long destAddr)
throws IOException
{
return impl.rawCompress(inputAddr, inputSize, destAddr);
}
/**
* Zero-copy decompress using memory addresses.
*
* @param inputAddr input memory address
* @param inputSize input byte size
* @param destAddr destination address of the uncompressed data
* @return the uncompressed data size
* @throws IOException
*/
public static long rawUncompress(long inputAddr, long inputSize, long destAddr)
throws IOException
{
return impl.rawUncompress(inputAddr, inputSize, destAddr);
}
/**
* Compress the input data and produce a byte array of the uncompressed data
*
* @param data input array. The input MUST be an array type
* @param byteSize the input byte size
* @return compressed data
*/
public static byte[] rawCompress(Object data, int byteSize)
throws IOException
{
byte[] buf = new byte[Snappy.maxCompressedLength(byteSize)];
int compressedByteSize = impl.rawCompress(data, 0, byteSize, buf, 0);
byte[] result = new byte[compressedByteSize];
System.arraycopy(buf, 0, result, 0, compressedByteSize);
return result;
}
/**
* Compress the input buffer [offset,... ,offset+length) contents, then
* write the compressed data to the output buffer[offset, ...)
*
* @param input input array. This MUST be a primitive array type
* @param inputOffset byte offset at the output array
* @param inputLength byte length of the input data
* @param output output array. This MUST be a primitive array type
* @param outputOffset byte offset at the output array
* @return byte size of the compressed data
* @throws IOException
*/
public static int rawCompress(Object input, int inputOffset, int inputLength, byte[] output, int outputOffset)
throws IOException
{
if (input == null || output == null) {
throw new NullPointerException("input or output is null");
}
int compressedSize = impl
.rawCompress(input, inputOffset, inputLength, output, outputOffset);
return compressedSize;
}
/**
* Uncompress the content in the input buffer. The uncompressed data is
* written to the output buffer.
*
* Note that if you pass the wrong data or the range [inputOffset,
* inputOffset + inputLength) that cannot be uncompressed, your JVM might
* crash due to the access violation exception issued in the native code
* written in C++. To avoid this type of crash, use
* {@link #isValidCompressedBuffer(byte[], int, int)} first.
*
* @param input input byte array
* @param inputOffset byte offset in the input byte array
* @param inputLength byte length of the input data
* @param output output buffer, MUST be a primitive type array
* @param outputOffset byte offset in the output buffer
* @return the byte size of the uncompressed data
* @throws IOException when failed to uncompress the input data
*/
public static int rawUncompress(byte[] input, int inputOffset, int inputLength, Object output, int outputOffset)
throws IOException
{
if (input == null || output == null) {
throw new NullPointerException("input or output is null");
}
return impl.rawUncompress(input, inputOffset, inputLength, output, outputOffset);
}
/**
* High-level API for uncompressing the input byte array.
*
* @param input
* @return the uncompressed byte array
* @throws IOException
*/
public static byte[] uncompress(byte[] input)
throws IOException
{
byte[] result = new byte[Snappy.uncompressedLength(input)];
Snappy.uncompress(input, 0, input.length, result, 0);
return result;
}
/**
* Uncompress the content in the input buffer. The uncompressed data is
* written to the output buffer.
*
* Note that if you pass the wrong data or the range [inputOffset,
* inputOffset + inputLength) that cannot be uncompressed, your JVM might
* crash due to the access violation exception issued in the native code
* written in C++. To avoid this type of crash, use
* {@link #isValidCompressedBuffer(byte[], int, int)} first.
*
* @param input
* @param inputOffset
* @param inputLength
* @param output
* @param outputOffset
* @return the byte size of the uncompressed data
* @throws IOException
*/
public static int uncompress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset)
throws IOException
{
return rawUncompress(input, inputOffset, inputLength, output, outputOffset);
}
/**
* Uncompress the content in the input buffer. The result is dumped to the
* specified output buffer.
*
* Note that if you pass the wrong data or the range [pos(), limit()) that
* cannot be uncompressed, your JVM might crash due to the access violation
* exception issued in the native code written in C++. To avoid this type of
* crash, use {@link #isValidCompressedBuffer(ByteBuffer)} first.
*
* @param compressed buffer[pos() ... limit()) containing the input data
* @param uncompressed output of the the uncompressed data. It uses buffer[pos()..]
* @return uncompressed data size
* @throws IOException when failed to uncompress the given input
* @throws SnappyError when the input is not a direct buffer
*/
public static int uncompress(ByteBuffer compressed, ByteBuffer uncompressed)
throws IOException
{
if (!compressed.isDirect()) {
throw new SnappyError(SnappyErrorCode.NOT_A_DIRECT_BUFFER, "input is not a direct buffer");
}
if (!uncompressed.isDirect()) {
throw new SnappyError(SnappyErrorCode.NOT_A_DIRECT_BUFFER, "destination is not a direct buffer");
}
int cPos = compressed.position();
int cLen = compressed.remaining();
// pos limit
// [ ......UUUUUU.........]
int decompressedSize = impl.rawUncompress(compressed, cPos, cLen, uncompressed,
uncompressed.position());
uncompressed.limit(uncompressed.position() + decompressedSize);
return decompressedSize;
}
/**
* Uncompress the input data as char array
*
* @param input
* @return the uncompressed data
* @throws IOException
*/
public static char[] uncompressCharArray(byte[] input)
throws IOException
{
return uncompressCharArray(input, 0, input.length);
}
/**
* Uncompress the input[offset, .., offset+length) as a char array
*
* @param input
* @param offset
* @param length
* @return the uncompressed data
* @throws IOException
*/
public static char[] uncompressCharArray(byte[] input, int offset, int length)
throws IOException
{
int uncompressedLength = Snappy.uncompressedLength(input, offset, length);
char[] result = new char[uncompressedLength / 2];
impl.rawUncompress(input, offset, length, result, 0);
return result;
}
/**
* Uncompress the input as a double array
*
* @param input
* @return the uncompressed data
* @throws IOException
*/
public static double[] uncompressDoubleArray(byte[] input)
throws IOException
{
int uncompressedLength = Snappy.uncompressedLength(input, 0, input.length);
double[] result = new double[uncompressedLength / 8];
impl.rawUncompress(input, 0, input.length, result, 0);
return result;
}
/**
* Get the uncompressed byte size of the given compressed input. This
* operation takes O(1) time.
*
* @param input
* @return uncompressed byte size of the the given input data
* @throws IOException when failed to uncompress the given input. The error code is
* {@link SnappyErrorCode#PARSING_ERROR}
*/
public static int uncompressedLength(byte[] input)
throws IOException
{
return impl.uncompressedLength(input, 0, input.length);
}
/**
* Get the uncompressed byte size of the given compressed input. This
* operation takes O(1) time.
*
* @param input
* @param offset
* @param length
* @return uncompressed byte size of the the given input data
* @throws IOException when failed to uncompress the given input. The error code is
* {@link SnappyErrorCode#PARSING_ERROR}
*/
public static int uncompressedLength(byte[] input, int offset, int length)
throws IOException
{
if (input == null) {
throw new NullPointerException("input is null");
}
return impl.uncompressedLength(input, offset, length);
}
/**
* Get the uncompressed byte size of the given compressed input. This
* operation takes O(1) time.
*
* @param compressed input data [pos() ... limit())
* @return uncompressed byte length of the given input
* @throws IOException when failed to uncompress the given input. The error code is
* {@link SnappyErrorCode#PARSING_ERROR}
* @throws SnappyError when the input is not a direct buffer
*/
public static int uncompressedLength(ByteBuffer compressed)
throws IOException
{
if (!compressed.isDirect()) {
throw new SnappyError(SnappyErrorCode.NOT_A_DIRECT_BUFFER, "input is not a direct buffer");
}
return impl.uncompressedLength(compressed, compressed.position(), compressed.remaining());
}
/**
* Get the uncompressed byte size of the given compressed input. This operation takes O(1) time.
*
* @param inputAddr compressed data address
* @param len byte length of the input
* @return uncompressed byte length of the given input
* @throws IOException when failed to uncompress the given input. The error code is
* {@link SnappyErrorCode#PARSING_ERROR}
*/
public static long uncompressedLength(long inputAddr, long len)
throws IOException
{
return impl.uncompressedLength(inputAddr, len);
}
/**
* Uncompress the input as a float array
*
* @param input
* @return the uncompressed data
* @throws IOException
*/
public static float[] uncompressFloatArray(byte[] input)
throws IOException
{
return uncompressFloatArray(input, 0, input.length);
}
/**
* Uncompress the input[offset, offset+length) as a float array
*
* @param input
* @param offset
* @param length
* @return the uncompressed data
* @throws IOException
*/
public static float[] uncompressFloatArray(byte[] input, int offset, int length)
throws IOException
{
int uncompressedLength = Snappy.uncompressedLength(input, offset, length);
float[] result = new float[uncompressedLength / 4];
impl.rawUncompress(input, offset, length, result, 0);
return result;
}
/**
* Uncompress the input data as an int array
*
* @param input
* @return the uncompressed data
* @throws IOException
*/
public static int[] uncompressIntArray(byte[] input)
throws IOException
{
return uncompressIntArray(input, 0, input.length);
}
/**
* Uncompress the input[offset, offset+length) as an int array
*
* @param input
* @param offset
* @param length
* @return the uncompressed data
* @throws IOException
*/
public static int[] uncompressIntArray(byte[] input, int offset, int length)
throws IOException
{
int uncompressedLength = Snappy.uncompressedLength(input, offset, length);
int[] result = new int[uncompressedLength / 4];
impl.rawUncompress(input, offset, length, result, 0);
return result;
}
/**
* Uncompress the input data as a long array
*
* @param input
* @return the uncompressed data
* @throws IOException
*/
public static long[] uncompressLongArray(byte[] input)
throws IOException
{
return uncompressLongArray(input, 0, input.length);
}
/**
* Uncompress the input[offset, offset+length) as a long array
*
* @param input
* @param offset
* @param length
* @return the uncompressed data
* @throws IOException
*/
public static long[] uncompressLongArray(byte[] input, int offset, int length)
throws IOException
{
int uncompressedLength = Snappy.uncompressedLength(input, offset, length);
long[] result = new long[uncompressedLength / 8];
impl.rawUncompress(input, offset, length, result, 0);
return result;
}
/**
* Uncompress the input as a short array
*
* @param input
* @return the uncompressed data
* @throws IOException
*/
public static short[] uncompressShortArray(byte[] input)
throws IOException
{
return uncompressShortArray(input, 0, input.length);
}
/**
* Uncompress the input[offset, offset+length) as a short array
*
* @param input
* @param offset
* @param length
* @return the uncompressed data
* @throws IOException
*/
public static short[] uncompressShortArray(byte[] input, int offset, int length)
throws IOException
{
int uncompressedLength = Snappy.uncompressedLength(input, offset, length);
short[] result = new short[uncompressedLength / 2];
impl.rawUncompress(input, offset, length, result, 0);
return result;
}
/**
* Uncompress the input as a String
*
* @param input
* @return the uncompressed dasta
* @throws IOException
*/
public static String uncompressString(byte[] input)
throws IOException
{
try {
return uncompressString(input, "UTF-8");
}
catch (UnsupportedEncodingException e) {
throw new IllegalStateException("UTF-8 decoder is not found");
}
}
/**
* Uncompress the input[offset, offset+length) as a String
*
* @param input
* @param offset
* @param length
* @return the uncompressed data
* @throws IOException
*/
public static String uncompressString(byte[] input, int offset, int length)
throws IOException
{
try {
return uncompressString(input, offset, length, "UTF-8");
}
catch (UnsupportedEncodingException e) {
throw new IllegalStateException("UTF-8 decoder is not found");
}
}
/**
* Uncompress the input[offset, offset+length) as a String of the given
* encoding
*
* @param input
* @param offset
* @param length
* @param encoding
* @return the uncompressed data
* @throws IOException
*/
public static String uncompressString(byte[] input, int offset, int length, String encoding)
throws IOException,
UnsupportedEncodingException
{
byte[] uncompressed = new byte[uncompressedLength(input, offset, length)];
uncompress(input, offset, length, uncompressed, 0);
return new String(uncompressed, encoding);
}
/**
* Uncompress the input[offset, offset+length) as a String of the given
* encoding
*
* @param input
* @param offset
* @param length
* @param encoding
* @return the uncompressed data
* @throws IOException
*/
public static String uncompressString(byte[] input, int offset, int length, Charset encoding)
throws IOException,
UnsupportedEncodingException
{
byte[] uncompressed = new byte[uncompressedLength(input, offset, length)];
uncompress(input, offset, length, uncompressed, 0);
return new String(uncompressed, encoding);
}
/**
* Uncompress the input as a String of the given encoding
*
* @param input
* @param encoding
* @return the uncompressed data
* @throws IOException
* @throws UnsupportedEncodingException
*/
public static String uncompressString(byte[] input, String encoding)
throws IOException,
UnsupportedEncodingException
{
byte[] uncompressed = uncompress(input);
return new String(uncompressed, encoding);
}
/**
* Uncompress the input as a String of the given encoding
*
* @param input
* @param encoding
* @return the uncompressed data
* @throws IOException
*/
public static String uncompressString(byte[] input, Charset encoding)
throws IOException,
UnsupportedEncodingException
{
byte[] uncompressed = uncompress(input);
return new String(uncompressed, encoding);
}
}
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