| java.lang.Object
 net.sf.jasperreports.engine.util.JRSwapFile
All known Subclasses: net.sf.jasperreports.engine.util.JRConcurrentSwapFile,
| JRSwapFile | | public class JRSwapFile (Code) | | Swap file implementation that can be used as a disk cache for arbitrary binary data.
Fixed-size blocks are allocated inside the swap file when a caller wants to write data.
The caller receives a handle to the allocated area based on which it can read the data
or free the area.
The implementation is thread-safe. I/O operations are performed in synchronized blocks,
only one thread would do a read or write at one moment.
author:
Lucian Chirita (lucianc@users.sourceforge.net)
version:
$Id: JRSwapFile.java 1744 2007-06-11 14:30:11Z teodord $ |
| Inner Class :protected static class LongQueue | |
| Inner Class :public static class SwapHandle | |
| Constructor Summary | |
| public | JRSwapFile(String directory, int blockSize, int minGrowCount)
Creates a swap file. |
| Method Summary | |
| public void | dispose()
Closes and deletes the swap file. | | protected void | finalize()
| | public void | free(SwapHandle handle)
Frees an allocated area. | | protected synchronized void | freeBlocks(long[] offsets)
| | public byte[] | read(SwapHandle handle, boolean free)
Reads all the data from an allocated area. | | protected void | read(byte[] data, int dataOffset, int dataLength, long fileOffset)
| | protected synchronized long[] | reserveFreeBlocks(int blockCount)
| | public SwapHandle | write(byte[] data)
Allocates an area in the swap file and writes data in it. | | protected void | write(byte[] data, int dataSize, int dataOffset, long fileOffset)
|
| JRSwapFile | | public JRSwapFile(String directory, int blockSize, int minGrowCount)(Code) | | Creates a swap file.
The file name is generated automatically.
Parameters:
directory - the directory where the file should be created.
Parameters:
blockSize - the size of the blocks allocated by the swap file
Parameters:
minGrowCount - the minimum number of blocks by which the swap file grows when full |
| dispose | | public void dispose()(Code) | | Closes and deletes the swap file.
|
| free | | public void free(SwapHandle handle)(Code) | | Frees an allocated area.
Parameters:
handle - the allocated area handle |
| freeBlocks | | protected synchronized void freeBlocks(long[] offsets)(Code) | | |
| read | | public byte[] read(SwapHandle handle, boolean free) throws IOException(Code) | | Reads all the data from an allocated area.
Parameters:
handle - the allocated area handle
Parameters:
free - whether to free the area after reading the whole data saved in an allocated area
throws:
IOException - |
| read | | protected void read(byte[] data, int dataOffset, int dataLength, long fileOffset) throws IOException(Code) | | |
| reserveFreeBlocks | | protected synchronized long[] reserveFreeBlocks(int blockCount) throws IOException(Code) | | |
| write | | public SwapHandle write(byte[] data) throws IOException(Code) | | Allocates an area in the swap file and writes data in it.
Parameters:
data - the data for which to allocate an area in the file a handle to the allocated area
throws:
IOException - |
| write | | protected void write(byte[] data, int dataSize, int dataOffset, long fileOffset) throws IOException(Code) | | |
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