Package libcore.io

Class MemoryMappedFile

java.lang.Object

libcore.io.MemoryMappedFile

All Implemented Interfaces:

AutoCloseable

public final class MemoryMappedFile
extends Object
implements AutoCloseable

A memory-mapped file. Use #mmap to map a file, close() to unmap a file, and either bigEndianIterator() or littleEndianIterator() to get a seekable BufferIterator over the mapped data.

Constructor Summary

Constructors

Constructor	Description
MemoryMappedFile(long address, long size)	Use this if you've called mmap yourself.

Method Summary

Modifier and Type	Method	Description
BufferIterator	bigEndianIterator()	Returns a new iterator that treats the mapped data as big-endian.
void	close()	Unmaps this memory-mapped file using munmap(2).
BufferIterator	littleEndianIterator()	Returns a new iterator that treats the mapped data as little-endian.
static MemoryMappedFile	mmapRO(String path)	Use this to mmap the whole file read-only.
long	size()	Returns the size in bytes of the memory-mapped region.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

MemoryMappedFile

public MemoryMappedFile(long address,
long size)

Use this if you've called mmap yourself.

Method Details

mmapRO

public static MemoryMappedFile mmapRO(String path)
                               throws ErrnoException

Use this to mmap the whole file read-only.

Throws:

ErrnoException

close

public void close()
           throws ErrnoException

Unmaps this memory-mapped file using munmap(2). This is a no-op if close has already been called. Note that this class does not use finalization; you must call close yourself. Calling this method invalidates any iterators over this MemoryMappedFile. It is an error to use such an iterator after calling close.

Specified by:

close in interface AutoCloseable

Throws:

ErrnoException

bigEndianIterator

public BufferIterator bigEndianIterator()

Returns a new iterator that treats the mapped data as big-endian.

littleEndianIterator

public BufferIterator littleEndianIterator()

Returns a new iterator that treats the mapped data as little-endian.

size

public long size()

Returns the size in bytes of the memory-mapped region.