com::cosylab::logging::client::cache::LogBufferedFileCache Class Reference

Inheritance diagram for com::cosylab::logging::client::cache::LogBufferedFileCache:

Collaboration diagram for com::cosylab::logging::client::cache::LogBufferedFileCache:

Classes
class	BufferedCacheItem
Public Member Functions
	LogBufferedFileCache (int writeBufferSize) throws LogCacheException
	LogBufferedFileCache () throws LogCacheException
synchronized void	clear () throws LogCacheException
synchronized ILogEntry	getLog (Integer key) throws LogCacheException
synchronized void	deleteLog (Integer key) throws LogCacheException
synchronized void	deleteLogs (Collection< Integer > keys) throws LogCacheException
synchronized int	add (ILogEntry log) throws LogCacheException
void	flushBuffer () throws LogCacheException
synchronized int	getSize ()
long	getFileSize () throws IOException
synchronized final int	getBufferSize ()
Integer	getFirstLog ()
int	getFirstLogs (int n, Collection< Integer > keys)
Integer	getLastLog ()
Set< Integer >	keySet ()
Iterator< ILogEntry >	iterator ()
synchronized void	replaceLog (Integer key, ILogEntry log) throws LogCacheException
Static Public Attributes
static final String	WRITEBUFFERSIZE_PROPERTY_NAME = "jlog.cache.writebuffersize"
static final int	DEFAULT_WRITEBUFFERSIZE = 8192
Static Private Member Functions
static int	getDefaultWriteCacheSize ()
Private Attributes
TreeMap< Integer, BufferedCacheItem >	buffer = new TreeMap<Integer,BufferedCacheItem>()
int	size
volatile long	bufferFileSize = 0

Detailed Description

This class extends the LogFileCache adding the buffering of the logs that must be written on disk.

It uses a WriteBuffer to store the logs to write on disk. The purpose of this class is to write several logs at once reducing the write operations on disk.

The buffer stores the logs when they are added. It flushes the buffer on disk when the number of logs in memory exceeds the maximum size. This means that the number of chars written on the file cache at once is not fixed but depends on the lengths of the logs stored in this buffer. To enhance performance and to have the size of the file always available, the buffer stores the log together with other info in Map of BufferedCacheItem

Author:: acaproni

Constructor & Destructor Documentation

com::cosylab::logging::client::cache::LogBufferedFileCache::LogBufferedFileCache ( int writeBufferSize ) throws LogCacheException [inline]

Build a LogBufferedFileCache with the given size for the cache and the write buffer. If there isn't enough memory for the cache, tries with a smmaller size.

Parameters:

	cacheSize	The size of the cache
	writeBufferSize	The size of the write buffer

Exceptions:

LogCacheException

If there is'nt enough memory for a buffer of at least 32 logs

References size.

com::cosylab::logging::client::cache::LogBufferedFileCache::LogBufferedFileCache ( ) throws LogCacheException [inline]

Build a LogBufferedFileCache with the default sizes for the write buffer

Exceptions:

LogCacheException

See also:: LogBufferedFileCache.getDefaultWriteCacheSize

References getDefaultWriteCacheSize().

Member Function Documentation

synchronized int com::cosylab::logging::client::cache::LogBufferedFileCache::add ( ILogEntry log ) throws LogCacheException [inline]

Append a log to the cache

Parameters:

log

The log to append in the cache

Returns:: The key of the added log

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer, bufferFileSize, flushBuffer(), com::cosylab::logging::client::cache::LogBufferedFileCache::BufferedCacheItem::getLogCacheString(), com::cosylab::logging::client::cache::LogFileCache::logID, size, and com::cosylab::logging::client::cache::LogFileCache::toCacheString().

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::addLog(), alma::acs::jlog::test::DeleteLogTest::testDeleteLogsFromLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetFirstLogLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetLastLogLogBufferedFileCache(), and alma::acs::jlog::test::DeleteLogTest::testLogBufferedFileCacheDelete().

synchronized void com::cosylab::logging::client::cache::LogBufferedFileCache::clear ( ) throws LogCacheException [inline]

Empty the cache

Exceptions:

IOException

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer, and bufferFileSize.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::clear(), and alma::acs::jlog::test::DeleteLogTest::testDeleteLogsFromLogBufferedFileCache().

synchronized void com::cosylab::logging::client::cache::LogBufferedFileCache::deleteLog ( Integer key ) throws LogCacheException [inline]

Delete a log with the given key

Parameters:

pos

The key of the log to delete

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer, bufferFileSize, and com::cosylab::logging::client::cache::LogBufferedFileCache::BufferedCacheItem::getLogCacheString().

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::deleteLog(), alma::acs::jlog::test::DeleteLogTest::testGetFirstLogLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetLastLogLogBufferedFileCache(), and alma::acs::jlog::test::DeleteLogTest::testLogBufferedFileCacheDelete().

synchronized void com::cosylab::logging::client::cache::LogBufferedFileCache::deleteLogs ( Collection< Integer > keys ) throws LogCacheException [inline]

Delete a collection of logs

Parameters:

keys

The keys of the logs to remove from the cache

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer, bufferFileSize, and com::cosylab::logging::client::cache::LogBufferedFileCache::BufferedCacheItem::getLogCacheString().

Referenced by alma::acs::jlog::test::DeleteLogTest::testDeleteLogsFromLogBufferedFileCache().

void com::cosylab::logging::client::cache::LogBufferedFileCache::flushBuffer ( ) throws LogCacheException [inline]

Flush all the logs on file

References buffer, bufferFileSize, com::cosylab::logging::client::cache::LogFileCache::file, com::cosylab::logging::client::cache::LogBufferedFileCache::BufferedCacheItem::getLogCacheString(), com::cosylab::logging::client::cache::LogFileCache::index, and com::cosylab::logging::client::cache::LogFileCache::initCache().

Referenced by add(), and com::cosylab::logging::client::cache::MultiFileTableRecord::flushBuffer().

synchronized final int com::cosylab::logging::client::cache::LogBufferedFileCache::getBufferSize ( ) [inline]

Returns:: The number of logs actually in the buffer

References buffer.

Referenced by alma::acs::jlog::test::DeleteLogTest::testGetFirstLogLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetLastLogLogBufferedFileCache(), and alma::acs::jlog::test::DeleteLogTest::testLogBufferedFileCacheDelete().

static int com::cosylab::logging::client::cache::LogBufferedFileCache::getDefaultWriteCacheSize ( ) [inline, static, private]

Gets the default size ot the write buffer, which comes either from the system property jlog.cache.writebuffersize (see WRITEBUFFERSIZE_PROPERTY_NAME) or, if this property is undefined or invalid, from the fixed size given by DEFAULT_WRITEBUFFERSIZE.

Returns:: the default size of the write buffer to be used if none is given in the constructor

References DEFAULT_WRITEBUFFERSIZE, and WRITEBUFFERSIZE_PROPERTY_NAME.

Referenced by LogBufferedFileCache().

long com::cosylab::logging::client::cache::LogBufferedFileCache::getFileSize ( ) throws IOException [inline]

Return the length of the file on disk taking into account the length of the string to write on the disk for the logs in the buffer.

Returns:: The size of the file cache

Exceptions:

IOException

in case of I/O error

See also:: java.io.RandomAccessFile

Reimplemented from com::cosylab::logging::client::cache::LogFileCache.

References bufferFileSize.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::getFileSize().

Integer com::cosylab::logging::client::cache::LogBufferedFileCache::getFirstLog ( ) [inline]

Return the key of the first valid log (FIFO). The key of the first log is 0 but it can change if the log 0 has been deleted.

Returns:: The key of the first log null if the cache is empty

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::getFirstLog(), alma::acs::jlog::test::DeleteLogTest::testDeleteLogsFromLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetFirstLogLogBufferedFileCache(), and alma::acs::jlog::test::DeleteLogTest::testGetLastLogLogBufferedFileCache().

int com::cosylab::logging::client::cache::LogBufferedFileCache::getFirstLogs	(	int	n,
		Collection< Integer >	keys
	)			`[inline]`

Append at most n keys from the first valid logs to the collection. First here means first in the FIFO policy.

The number of added keys can be less then n if the cache doesn't contain enough logs.

Parameters:

	n	The desired number of keys of first logs
	keys	The collection to add they keys to

Returns:: The number of keys effectively added

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::getFirstLogs().

Integer com::cosylab::logging::client::cache::LogBufferedFileCache::getLastLog ( ) [inline]

Return the key of the last valid log (FIFO) The key of the last log is the key of the last inserted log but it can cheang if such log has been deleted

Returns:: The key of the last inserted log null if th cache is empty

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::getLastLog(), and alma::acs::jlog::test::DeleteLogTest::testGetLastLogLogBufferedFileCache().

synchronized ILogEntry com::cosylab::logging::client::cache::LogBufferedFileCache::getLog ( Integer key ) throws LogCacheException [inline]

Return the log with the given key

Parameters:

key

The key of the log

Returns:: The LogEntryXML or null in case of error

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer, and com::cosylab::logging::client::cache::LogBufferedFileCache::BufferedCacheItem::getLogEntry().

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::getLog(), alma::acs::jlog::test::DeleteLogTest::testDeleteLogsFromLogBufferedFileCache(), and alma::acs::jlog::test::DeleteLogTest::testLogBufferedFileCacheDelete().

synchronized int com::cosylab::logging::client::cache::LogBufferedFileCache::getSize ( ) [inline]

Return the number of logs in cache

Returns:: The number of logs in cache

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::getNumOfLogs(), com::cosylab::logging::client::cache::MultiFileTableRecord::isEmpty(), alma::acs::jlog::test::DeleteLogTest::testDeleteLogsFromLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetFirstLogLogBufferedFileCache(), alma::acs::jlog::test::DeleteLogTest::testGetLastLogLogBufferedFileCache(), and alma::acs::jlog::test::DeleteLogTest::testLogBufferedFileCacheDelete().

Iterator<ILogEntry> com::cosylab::logging::client::cache::LogBufferedFileCache::iterator ( ) [inline]

Return an iterator over the logs in cache

Implements com::cosylab::logging::client::cache::ILogMap.

Set<Integer> com::cosylab::logging::client::cache::LogBufferedFileCache::keySet ( ) [inline]

Return a set with all the keys of the logs in cache

Returns:: The keys of the logs in cache

Implements com::cosylab::logging::client::cache::ILogMap.

References buffer.

Referenced by com::cosylab::logging::client::cache::MultiFileTableRecord::keySet().

synchronized void com::cosylab::logging::client::cache::LogBufferedFileCache::replaceLog	(	Integer	key,
		ILogEntry	log
	)			throws LogCacheException `[inline]`