H2 Database Engine 2.3.232 · org.h2.store.fs.zip.FileZip

Modifier and Type	Field and Description
private final ZipEntry	entry
private final ZipFile	file
private InputStream	in
private long	inPos
private final long	length
private long	pos
private static final byte[]	SKIP_BUFFER
private boolean	skipUsingRead

Access	Constructor and Description
pack-priv	FileZip(ZipFile file, ZipEntry entry)

Method Summary

Modifier and Type	Method and Description
public void	force(boolean If `true` then this method is required to force changes to both the file's content and metadata to be written to storage; otherwise, it need only force content changes to be written metaData) Overrides org.h2.store.fs.FileBase.force. Forces any updates to this channel's file to be written to the storage device that contains it.
protected void	implCloseChannel() Overrides org.h2.store.fs.FileBase.implCloseChannel. Closes this channel.
public long	position() Implements abstract java.nio.channels.FileChannel.position. Implements java.nio.channels.SeekableByteChannel.position. Returns this channel's file position.
public FileChannel	position(long The new position, a non-negative integer counting the number of bytes from the beginning of the file newPos) Implements abstract java.nio.channels.FileChannel.position. Implements java.nio.channels.SeekableByteChannel.position. Sets this channel's file position.
public int	read(ByteBuffer The buffer into which bytes are to be transferred dst) Implements abstract java.nio.channels.FileChannel.read. Implements java.nio.channels.SeekableByteChannel.read, java.nio.channels.ReadableByteChannel.read. Reads a sequence of bytes from this channel into the given buffer.
private void	seek()
public long	size() Implements abstract java.nio.channels.FileChannel.size. Implements java.nio.channels.SeekableByteChannel.size. Returns the current size of this channel's file.
public FileChannel	truncate(long The new size, a non-negative byte count newLength) Implements abstract java.nio.channels.FileChannel.truncate. Implements java.nio.channels.SeekableByteChannel.truncate. Truncates this channel's file to the given size.
public synchronized FileLock	tryLock(long The position at which the locked region is to start; must be non-negative position, long The size of the locked region; must be non-negative, and the sum `position` + `size` must be non-negative. A value of zero means to lock all bytes from the specified starting position to the end of the file, regardless of whether the file is subsequently extended or truncated size, boolean `true` to request a shared lock, `false` to request an exclusive lock shared) Overrides org.h2.store.fs.FileBase.tryLock. Attempts to acquire a lock on the given region of this channel's file.
public int	write(ByteBuffer The buffer from which bytes are to be retrieved src) Implements abstract java.nio.channels.FileChannel.write. Implements java.nio.channels.SeekableByteChannel.write, java.nio.channels.WritableByteChannel.write. Writes a sequence of bytes to this channel from the given buffer.

Inherited from org.h2.store.fs.FileBase:: lock map read read transferFrom transferTo write write

entry	back to summary
private final ZipEntry entry

file	back to summary
private final ZipFile file

in	back to summary
private InputStream in

inPos	back to summary
private long inPos

length	back to summary
private final long length

pos	back to summary
private long pos

SKIP_BUFFER	back to summary
private static final byte[] SKIP_BUFFER

skipUsingRead	back to summary
private boolean skipUsingRead

FileZip	back to summary
pack-priv FileZip(ZipFile file, ZipEntry entry)

Method Detail

force back to summary

force	back to summary
public void force(boolean metaData) throws IOException Overrides org.h2.store.fs.FileBase.force. Doc from java.nio.channels.FileChannel.force. Forces any updates to this channel's file to be written to the storage device that contains it. If this channel's file resides on a local storage device then when this method returns it is guaranteed that all changes made to the file since this channel was created, or since this method was last invoked, will have been written to that device. This is useful for ensuring that critical information is not lost in the event of a system crash. If the file does not reside on a local device then no such guarantee is made. The `metaData` parameter can be used to limit the number of I/O operations that this method is required to perform. Passing `false` for this parameter indicates that only updates to the file's content need be written to storage; passing `true` indicates that updates to both the file's content and metadata must be written, which generally requires at least one more I/O operation. Whether this parameter actually has any effect is dependent upon the underlying operating system and is therefore unspecified. Invoking this method may cause an I/O operation to occur even if the channel was only opened for reading. Some operating systems, for example, maintain a last-access time as part of a file's metadata, and this time is updated whenever the file is read. Whether or not this is actually done is system-dependent and is therefore unspecified. This method is only guaranteed to force changes that were made to this channel's file via the methods defined in this class, or the methods defined by `java.io.FileOutputStream` or `java.io.RandomAccessFile` when the channel was obtained with the `getChannel` method. It may or may not force changes that were made by modifying the content of a `mapped byte buffer` obtained by invoking the `map` method. Invoking the `force` method of the mapped byte buffer will force changes made to the buffer's content to be written. Parameters metaData:boolean If `true` then this method is required to force changes to both the file's content and metadata to be written to storage; otherwise, it need only force content changes to be written Annotations @Override Exceptions IOException: If some other I/O error occurs

public void force(boolean metaData) throws IOException

Overrides org.h2.store.fs.FileBase.force.

Doc from java.nio.channels.FileChannel.force.

Forces any updates to this channel's file to be written to the storage device that contains it.

If this channel's file resides on a local storage device then when this method returns it is guaranteed that all changes made to the file since this channel was created, or since this method was last invoked, will have been written to that device. This is useful for ensuring that critical information is not lost in the event of a system crash.

If the file does not reside on a local device then no such guarantee is made.

The metaData parameter can be used to limit the number of I/O operations that this method is required to perform. Passing false for this parameter indicates that only updates to the file's content need be written to storage; passing true indicates that updates to both the file's content and metadata must be written, which generally requires at least one more I/O operation. Whether this parameter actually has any effect is dependent upon the underlying operating system and is therefore unspecified.

Invoking this method may cause an I/O operation to occur even if the channel was only opened for reading. Some operating systems, for example, maintain a last-access time as part of a file's metadata, and this time is updated whenever the file is read. Whether or not this is actually done is system-dependent and is therefore unspecified.

This method is only guaranteed to force changes that were made to this channel's file via the methods defined in this class, or the methods defined by java.io.FileOutputStream or java.io.RandomAccessFile when the channel was obtained with the getChannel method. It may or may not force changes that were made by modifying the content of a mapped byte buffer obtained by invoking the map method. Invoking the force method of the mapped byte buffer will force changes made to the buffer's content to be written.

Parameters

metaData:boolean: If true then this method is required to force changes to both the file's content and metadata to be written to storage; otherwise, it need only force content changes to be written

Annotations

@Override

Exceptions

IOException:: If some other I/O error occurs

implCloseChannel back to summary

implCloseChannel	back to summary
protected void implCloseChannel() throws IOException Overrides org.h2.store.fs.FileBase.implCloseChannel. Doc from java.nio.channels.spi.AbstractInterruptibleChannel.implCloseChannel. Closes this channel. This method is invoked by the `close` method in order to perform the actual work of closing the channel. This method is only invoked if the channel has not yet been closed, and it is never invoked more than once. An implementation of this method must arrange for any other thread that is blocked in an I/O operation upon this channel to return immediately, either by throwing an exception or by returning normally. Annotations @Override Exceptions IOException: If an I/O error occurs while closing the channel

protected void implCloseChannel() throws IOException

Overrides org.h2.store.fs.FileBase.implCloseChannel.

Doc from java.nio.channels.spi.AbstractInterruptibleChannel.implCloseChannel.

Closes this channel.

This method is invoked by the close method in order to perform the actual work of closing the channel. This method is only invoked if the channel has not yet been closed, and it is never invoked more than once.

An implementation of this method must arrange for any other thread that is blocked in an I/O operation upon this channel to return immediately, either by throwing an exception or by returning normally.

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs while closing the channel

position	back to summary
public long position() Implements abstract java.nio.channels.FileChannel.position. Implements java.nio.channels.SeekableByteChannel.position. Doc from java.nio.channels.FileChannel.position. Returns this channel's file position. Returns:long This channel's file position, a non-negative integer counting the number of bytes from the beginning of the file to the current position Annotations @Override

position

back to summary

public long position()

Implements abstract java.nio.channels.FileChannel.position.

Implements java.nio.channels.SeekableByteChannel.position.

Doc from java.nio.channels.FileChannel.position.

Returns this channel's file position.

Returns:long

This channel's file position, a non-negative integer counting the number of bytes from the beginning of the file to the current position

Annotations

@Override

position	back to summary
public FileChannel position(long newPos) Implements abstract java.nio.channels.FileChannel.position. Implements java.nio.channels.SeekableByteChannel.position. Doc from java.nio.channels.FileChannel.position. Sets this channel's file position. Setting the position to a value that is greater than the file's current size is legal but does not change the size of the file. A later attempt to read bytes at such a position will immediately return an end-of-file indication. A later attempt to write bytes at such a position will cause the file to be grown to accommodate the new bytes; the values of any bytes between the previous end-of-file and the newly-written bytes are unspecified. Parameters newPos:long The new position, a non-negative integer counting the number of bytes from the beginning of the file Returns:FileChannel This file channel Annotations @Override

position

back to summary

public FileChannel position(long newPos)

Implements abstract java.nio.channels.FileChannel.position.

Implements java.nio.channels.SeekableByteChannel.position.

Doc from java.nio.channels.FileChannel.position.

Sets this channel's file position.

Setting the position to a value that is greater than the file's current size is legal but does not change the size of the file. A later attempt to read bytes at such a position will immediately return an end-of-file indication. A later attempt to write bytes at such a position will cause the file to be grown to accommodate the new bytes; the values of any bytes between the previous end-of-file and the newly-written bytes are unspecified.

Parameters

newPos:long: The new position, a non-negative integer counting the number of bytes from the beginning of the file

Returns:FileChannel

This file channel

Annotations

@Override

read back to summary

read	back to summary
public int read(ByteBuffer dst) throws IOException Implements abstract java.nio.channels.FileChannel.read. Implements java.nio.channels.SeekableByteChannel.read, java.nio.channels.ReadableByteChannel.read. Doc from java.nio.channels.FileChannel.read. Reads a sequence of bytes from this channel into the given buffer. Bytes are read starting at this channel's current file position, and then the file position is updated with the number of bytes actually read. Otherwise this method behaves exactly as specified in the `ReadableByteChannel` interface. Parameters dst:ByteBuffer Doc from java.nio.channels.ReadableByteChannel.read. The buffer into which bytes are to be transferred Returns:int Doc from java.nio.channels.ReadableByteChannel.read. The number of bytes read, possibly zero, or `-1` if the channel has reached end-of-stream Annotations @Override Exceptions IOException: Doc from java.nio.channels.ReadableByteChannel.read. If some other I/O error occurs

public int read(ByteBuffer dst) throws IOException

Implements abstract java.nio.channels.FileChannel.read.

Implements java.nio.channels.SeekableByteChannel.read, java.nio.channels.ReadableByteChannel.read.

Doc from java.nio.channels.FileChannel.read.

Reads a sequence of bytes from this channel into the given buffer.

Bytes are read starting at this channel's current file position, and then the file position is updated with the number of bytes actually read. Otherwise this method behaves exactly as specified in the ReadableByteChannel interface.

Parameters

dst:ByteBuffer

Doc from java.nio.channels.ReadableByteChannel.read.

The buffer into which bytes are to be transferred

Returns:int

Doc from java.nio.channels.ReadableByteChannel.read.

The number of bytes read, possibly zero, or -1 if the channel has reached end-of-stream

Annotations

@Override

Exceptions

IOException:

Doc from java.nio.channels.ReadableByteChannel.read.

If some other I/O error occurs

seek	back to summary
private void seek() throws IOException

size	back to summary
public long size() Implements abstract java.nio.channels.FileChannel.size. Implements java.nio.channels.SeekableByteChannel.size. Doc from java.nio.channels.FileChannel.size. Returns the current size of this channel's file. Returns:long The current size of this channel's file, measured in bytes Annotations @Override

size

back to summary

public long size()

Implements abstract java.nio.channels.FileChannel.size.

Implements java.nio.channels.SeekableByteChannel.size.

Doc from java.nio.channels.FileChannel.size.

Returns the current size of this channel's file.

Returns:long

The current size of this channel's file, measured in bytes

Annotations

@Override

truncate	back to summary
public FileChannel truncate(long newLength) throws IOException Implements abstract java.nio.channels.FileChannel.truncate. Implements java.nio.channels.SeekableByteChannel.truncate. Doc from java.nio.channels.FileChannel.truncate. Truncates this channel's file to the given size. If the given size is less than the file's current size then the file is truncated, discarding any bytes beyond the new end of the file. If the given size is greater than or equal to the file's current size then the file is not modified. In either case, if this channel's file position is greater than the given size then it is set to that size. Parameters newLength:long The new size, a non-negative byte count Returns:FileChannel This file channel Annotations @Override Exceptions IOException: If some other I/O error occurs

truncate

back to summary

public FileChannel truncate(long newLength) throws IOException

Implements abstract java.nio.channels.FileChannel.truncate.

Implements java.nio.channels.SeekableByteChannel.truncate.

Doc from java.nio.channels.FileChannel.truncate.

Truncates this channel's file to the given size.

If the given size is less than the file's current size then the file is truncated, discarding any bytes beyond the new end of the file. If the given size is greater than or equal to the file's current size then the file is not modified. In either case, if this channel's file position is greater than the given size then it is set to that size.

Parameters

newLength:long: The new size, a non-negative byte count

Returns:FileChannel

This file channel

Annotations

@Override

Exceptions

IOException:: If some other I/O error occurs

tryLock back to summary

tryLock	back to summary
public synchronized FileLock tryLock(long position, long size, boolean shared) throws IOException Overrides org.h2.store.fs.FileBase.tryLock. Doc from java.nio.channels.FileChannel.tryLock. Attempts to acquire a lock on the given region of this channel's file. This method does not block. An invocation always returns immediately, either having acquired a lock on the requested region or having failed to do so. If it fails to acquire a lock because an overlapping lock is held by another program then it returns `null`. If it fails to acquire a lock for any other reason then an appropriate exception is thrown. The region specified by the `position` and `size` parameters need not be contained within, or even overlap, the actual underlying file. Lock regions are fixed in size; if a locked region initially contains the end of the file and the file grows beyond the region then the new portion of the file will not be covered by the lock. If a file is expected to grow in size and a lock on the entire file is required then a region starting at zero, and no smaller than the expected maximum size of the file, should be locked. The zero-argument `tryLock()` method simply locks a region of size `Long#MAX_VALUE`. If the `position` is non-negative and the `size` is zero, then a lock of size `Long.MAX_VALUE - position` is returned. Some operating systems do not support shared locks, in which case a request for a shared lock is automatically converted into a request for an exclusive lock. Whether the newly-acquired lock is shared or exclusive may be tested by invoking the resulting lock object's `isShared` method. File locks are held on behalf of the entire Java virtual machine. They are not suitable for controlling access to a file by multiple threads within the same virtual machine. Parameters position:long The position at which the locked region is to start; must be non-negative size:long The size of the locked region; must be non-negative, and the sum `position` + `size` must be non-negative. A value of zero means to lock all bytes from the specified starting position to the end of the file, regardless of whether the file is subsequently extended or truncated shared:boolean `true` to request a shared lock, `false` to request an exclusive lock Returns:FileLock A lock object representing the newly-acquired lock, or `null` if the lock could not be acquired because another program holds an overlapping lock Annotations @Override Exceptions IOException: If some other I/O error occurs

public synchronized FileLock tryLock(long position, long size, boolean shared) throws IOException

Overrides org.h2.store.fs.FileBase.tryLock.

Doc from java.nio.channels.FileChannel.tryLock.

Attempts to acquire a lock on the given region of this channel's file.

This method does not block. An invocation always returns immediately, either having acquired a lock on the requested region or having failed to do so. If it fails to acquire a lock because an overlapping lock is held by another program then it returns null. If it fails to acquire a lock for any other reason then an appropriate exception is thrown.

The region specified by the position and size parameters need not be contained within, or even overlap, the actual underlying file. Lock regions are fixed in size; if a locked region initially contains the end of the file and the file grows beyond the region then the new portion of the file will not be covered by the lock. If a file is expected to grow in size and a lock on the entire file is required then a region starting at zero, and no smaller than the expected maximum size of the file, should be locked. The zero-argument tryLock() method simply locks a region of size Long#MAX_VALUE. If the position is non-negative and the size is zero, then a lock of size Long.MAX_VALUE - position is returned.

Some operating systems do not support shared locks, in which case a request for a shared lock is automatically converted into a request for an exclusive lock. Whether the newly-acquired lock is shared or exclusive may be tested by invoking the resulting lock object's isShared method.

File locks are held on behalf of the entire Java virtual machine. They are not suitable for controlling access to a file by multiple threads within the same virtual machine.

Parameters

position:long: The position at which the locked region is to start; must be non-negative
size:long: The size of the locked region; must be non-negative, and the sum position + size must be non-negative. A value of zero means to lock all bytes from the specified starting position to the end of the file, regardless of whether the file is subsequently extended or truncated
shared:boolean: true to request a shared lock, false to request an exclusive lock

Returns:FileLock

A lock object representing the newly-acquired lock, or null if the lock could not be acquired because another program holds an overlapping lock

Annotations

@Override

Exceptions

IOException:: If some other I/O error occurs

write back to summary

write	back to summary
public int write(ByteBuffer src) throws IOException Implements abstract java.nio.channels.FileChannel.write. Implements java.nio.channels.SeekableByteChannel.write, java.nio.channels.WritableByteChannel.write. Doc from java.nio.channels.FileChannel.write. Writes a sequence of bytes to this channel from the given buffer. Bytes are written starting at this channel's current file position unless the channel is in append mode, in which case the position is first advanced to the end of the file. The file is grown, if necessary, to accommodate the written bytes, and then the file position is updated with the number of bytes actually written. Otherwise this method behaves exactly as specified by the `WritableByteChannel` interface. Parameters src:ByteBuffer Doc from java.nio.channels.WritableByteChannel.write. The buffer from which bytes are to be retrieved Returns:int Doc from java.nio.channels.WritableByteChannel.write. The number of bytes written, possibly zero Annotations @Override Exceptions IOException: Doc from java.nio.channels.WritableByteChannel.write. If some other I/O error occurs

public int write(ByteBuffer src) throws IOException

Implements abstract java.nio.channels.FileChannel.write.

Implements java.nio.channels.SeekableByteChannel.write, java.nio.channels.WritableByteChannel.write.

Doc from java.nio.channels.FileChannel.write.

Writes a sequence of bytes to this channel from the given buffer.

Bytes are written starting at this channel's current file position unless the channel is in append mode, in which case the position is first advanced to the end of the file. The file is grown, if necessary, to accommodate the written bytes, and then the file position is updated with the number of bytes actually written. Otherwise this method behaves exactly as specified by the WritableByteChannel interface.

Parameters

src:ByteBuffer

Doc from java.nio.channels.WritableByteChannel.write.

The buffer from which bytes are to be retrieved

Returns:int