H2 Database Engine 2.3.232 · org.h2.mvstore.FileStore

Modifier and Type	Class and Description
private static class	FileStore.BackgroundWriterThread A background writer thread to automatically store changes from time to time.
public class	FileStore.PageSerializationManager
private static class	FileStore.RemovedPageInfo

Field Summary

Modifier and Type	Field and Description
private int	autoCommitDelay The delay in milliseconds to automatically commit and write changes.
private final int	autoCompactFillRate
private long	autoCompactLastFileOpCount
private final AtomicReference<FileStore.BackgroundWriterThread>	backgroundWriterThread Reference to a background thread, which is expected to be running, if any.
pack-priv static final int	BLOCK_SIZE The block size (physical sector size) of the disk.
private ThreadPoolExecutor	bufferSaveExecutor Single-threaded executor for saving ByteBuffer as a new Chunk
private int	bufferSaveExecutorHWM
private final CacheLongKeyLIRS<Page<?, ?>>	cache The page cache.
pack-priv final ConcurrentHashMap<Integer, C>	chunks The map of chunks.
private final CacheLongKeyLIRS<long[]>	chunksToC Cache for chunks "Table of Content" used to translate page's sequential number within containing chunk into byte position within chunk's image.
private boolean	closed
private long	creationTime The time the store was created, in milliseconds since 1970.
private final Deque<C>	deadChunks
private String	fileName The file name.
private static final int	FORMAT_READ_MAX
private static final int	FORMAT_READ_MIN
private static final int	FORMAT_WRITE_MAX
private static final int	FORMAT_WRITE_MIN
pack-priv static final String	HDR_BLOCK
pack-priv static final String	HDR_BLOCK_SIZE
pack-priv static final String	HDR_CHUNK
pack-priv static final String	HDR_CLEAN
pack-priv static final String	HDR_CREATED
pack-priv static final String	HDR_FLETCHER
pack-priv static final String	HDR_FORMAT
pack-priv static final String	HDR_FORMAT_READ
pack-priv static final String	HDR_H
pack-priv static final String	HDR_VERSION
protected volatile C	lastChunk The newest chunk.
private int	lastChunkId
private long	lastCommitTime
private MVMap<String, String>	layout The layout map.
private final int	maxPageSize
public static final String	META_ID_KEY The key for the entry within "layout" map, which contains id of "meta" map.
pack-priv MVStore	mvStore
public static final int	PIPE_LENGTH
protected final AtomicLong	readBytes The number of read bytes.
protected final AtomicLong	readCount The number of read operations.
private boolean	readOnly Whether this store is read-only.
protected final boolean	recoveryMode
private final Queue<FileStore.RemovedPageInfo>	removedPages
private int	retentionTime For how long (in milliseconds) to retain a persisted chunk after it becomes irrelevant (not in use, because it only contains data from some old versions).
protected final ReentrantLock	saveChunkLock
private ThreadPoolExecutor	serializationExecutor Single-threaded executor for serialization of the store snapshot into ByteBuffer
private int	serializationExecutorHWM
private final ReentrantLock	serializationLock Lock guarding submission to serializationExecutor
private long	size The file size (cached).
protected final HashMap<String, Object>	storeHeader
private final Queue<WriteBuffer>	writeBufferPool
protected final AtomicLong	writeBytes The number of written bytes.
protected final AtomicLong	writeCount The number of write operations.

Access	Constructor and Description
protected	FileStore(Map<String, Object> config)

Method Summary

Modifier and Type	Method and Description
private void	acceptChunkOccupancyChanges(long time, long version) Apply the freed space to the chunk metadata.
public void	accountForRemovedPage(long the position of the page pos, long at which page was removed version, boolean whether page is considered pinned pinned, int sequential page number within chunk pageNo) Remove a page.
protected abstract void	adjustStoreToLastChunk() Make persistent changes after lastChunk was reset
protected abstract void	allocateChunkSpace(C to allocate space for chunk, WriteBuffer to allocate space for buff) Allocate logical space and assign position of the buffer within the store.
public abstract void	backup(ZipOutputStream out)
public final void	bind(MVStore mvStore)
pack-priv void	cachePage(Page<?, ?> the page page) Put the page in the cache.
pack-priv void	cacheToC(C chunk, long[] toc)
private int	calculatePageNo(long pos)
private static <C extends Chunk<C>> boolean	canOverwriteChunk(C c, long oldestVersionToKeep)
private long[]	cleanToCCache(C chunk)
public void	clear()
private void	clearCaches()
public void	close()
public boolean	Returns: if any chunk was re-written compact(int the minimum percentage of live entries targetFillRate, int the minimum number of bytes to write write) Try to increase the fill rate by re-writing partially full chunks.
private int	compactRewrite(Set<Integer> set)
public void	compactStore(long maxCompactTime)
protected abstract void	compactStore(int do not compact if store fill rate above this value (0-100) thresholdFillRate, long the maximum time in milliseconds to compact maxCompactTime, int the maximum amount of data to be written as part of this call maxWriteSize, MVStore that owns this FileStore mvStore) Compact store file, that is, compact blocks that have a low fill rate, and move chunks next to each other.
private C	createChunk(long time, long version)
protected abstract C	createChunk(int id)
public abstract C	Returns: the Chunk created createChunk(String the string s) Build a Chunk from the given string.
protected abstract C	createChunk(Map<String, String> map)
private C[]	createChunksArray(int sz)
private static <C extends Chunk<C>> HashSet<Integer>	createIdSet(Iterable<C> toCompact)
public final boolean	Returns: true if root was removed, false if it is not there deregisterMapRoot(int to deregister mapId) Performs final stage of map removal - delete root location info from the layout map.
protected final C	Returns: valid chunk or null if none found discoverChunk(long to start search from (found chunk footer should be no further than block-1) block) Discover a valid chunk, searching file backwards from the given block
protected abstract void	doHousekeeping(MVStore mvStore)
public final void	dropUnusedChunks()
public void	executeFileStoreOperation(Runnable operation)
protected final boolean	findLastChunkWithCompleteValidChunkSet(Comparator<C> chunkComparator, Map<Long, C> validChunksByLocation, boolean afterFullScan)
private int	findNewChunkId()
private Iterable<C>	findOldChunks(int writeLimit, int targetFillRate)
protected abstract void	freeChunkSpace(Iterable<C> chunks to be processed chunks) Mark the space occupied by specified chunks as free.
public final int	Returns: the delay in milliseconds, or 0 if auto-commit is disabled. getAutoCommitDelay() Get the auto-commit delay.
protected final int	getAutoCompactFillRate()
public int	getCacheHitRatio()
private static int	getCacheHitRatio(CacheLongKeyLIRS<?> cache)
public int	Returns: the cache size getCacheSize() Get the maximum cache size, in MB.
public int	Returns: the amount of memory used for caching getCacheSizeUsed() Get the amount of memory used for caching, in MB.
private C	Returns: the chunk getChunk(long the position pos) Get the chunk for the given position.
private int	Returns: number of existing chunks in store. getChunkCount() Get data chunks count.
private C	getChunkForVersion(long version)
protected final ConcurrentMap<Integer, C>	getChunks()
public int	Returns: the fill rate, in percent (100 is completely full) getChunksFillRate() Get the current fill rate (percentage of used space in the file).
private int	getChunksFillRate(boolean all)
protected Iterable<C>	getChunksFromLayoutMap()
private Iterable<C>	getChunksFromLayoutMap(MVMap<String, String> layoutMap)
public long	Returns: creation time getCreationTime() The time the store was created, in milliseconds since 1970.
public int	Returns: the retention time getDefaultRetentionTime() Get the default retention time for this store in milliseconds.
public String	Returns: the file name getFileName() Get the file name.
public abstract int	getFillRate()
public final Map<String, String>	Returns: the metadata map getLayoutMap() Get this store's layout map.
private MVMap<String, String>	getLayoutMap(long version)
private int	Returns: number of existing live pages in store. getLivePageCount() Get live data pages count.
public final long	getMaxPageSize()
public final int	getMetaMapId(IntSupplier nextIdSupplier)
protected final MVStore	getMvStore()
private int	Returns: number of existing pages in store. getPageCount() Get data pages count.
public long	Returns: the number of write operations getReadBytes() Get the number of read bytes since this store was opened.
public long	Returns: the number of read operations getReadCount() Get the number of read operations since this store was opened.
public final int	getRetentionTime()
pack-priv int	getRewritableChunksFillRate()
protected Collection<C>	getRewriteCandidates()
public final long	Returns: opaque "position" value, that should be used to read the page getRootPos(int to get root position for mapId) Get "position" of the root page for the specified map
public Map<String, Object>	Returns: the store header getStoreHeader() Get the store header.
private long	getTimeSinceCreation()
private long[]	getToC(C chunk)
public int	getTocCacheHitRatio()
private MVStoreException	getUnsupportedWriteFormatException(long format, int expectedFormat, String s)
public WriteBuffer	Returns: the buffer getWriteBuffer() Get a buffer for writing.
private long	Returns: the number of write operations getWriteBytes() Get the number of written bytes since this store was opened.
public long	Returns: the number of write operations getWriteCount() Get the number of write operations since this store was opened.
public final boolean	Returns: if there are any changes hasChangesSince(long version to take as a base for changes lastStoredVersion) Check whether there are any unsaved changes since specified version.
protected final boolean	hasPersistentData()
protected final void	init(String fileName, boolean readOnly)
protected final void	initializeCommonHeaderAttributes(long time)
protected abstract void	initializeStoreHeader(long time)
pack-priv boolean	isBackgroundThread()
protected final boolean	isIdle()
public final boolean	Returns: true if all data can be read isKnownVersion(long the version version) Check whether all data can be read from this version.
public boolean	isReadOnly()
public final boolean	isRegularMap(MVMap<?, ?> map)
private boolean	isRewritable(C chunk, long time)
private boolean	isSeasonedChunk(C chunk, long time)
public boolean	isSpaceReused()
private boolean	Returns: true if Chunk exists in the file and is valid, false otherwise isValidChunk(C to verify existence chunk) Read a chunk header and footer, and verify the stored data is consistent.
public final long	lastChunkVersion()
private int	lastMapId()
protected abstract void	markUsed(long the position in bytes pos, int the number of bytes length) Mark the space as in use.
public abstract void	open(String fileName, boolean readOnly, char[] encryptionKey)
public abstract FileStore<C>	open(String fileName, boolean readOnly)
public void	populateInfo(BiConsumer<String, String> consumer)
protected final void	processCommonHeaderAttributes()
protected final C	Returns: the chunk, or null if not successful readChunkFooter(long the index of the next block after the chunk block) Try to read a chunk footer.
private C	readChunkHeader(long block)
protected final C	Returns: the chunk, or null if the header or footer don't match or are not consistent readChunkHeaderAndFooter(long the block block, int of the chunk expectedId) Read a chunk header and footer, and verify the stored data is consistent.
protected final C	readChunkHeaderOptionally(long block, int expectedId)
protected final C	readChunkHeaderOptionally(long block)
public abstract ByteBuffer	Returns: the byte buffer with data requested readFully(C that owns data to be read chunk, long the read "position" pos, int the number of bytes to read len) Read data from the store.
protected final ByteBuffer	readFully(FileChannel file, long pos, int len)
pack-priv <K, V> Page<K, V>	Returns: the page readPage(MVMap<K, V> the map map, long the page position pos) Read a page.
private <K, V> Page<K, V>	readPageFromCache(long pos)
protected abstract void	readStoreHeader(boolean recoveryMode)
protected final void	registerDeadChunk(C chunk)
public void	releaseWriteBuffer(WriteBuffer the buffer than can be re-used buff) Release a buffer for writing.
protected boolean	rewriteChunks(int writeLimit, int targetFillRate)
private int	rewriteChunks(Set<Integer> set, boolean secondPass)
public final void	rollbackTo(long version)
public void	saveChunkMetadataChanges(C to save chunk) Store chunk's serialized metadata as an entry in a layout map.
private void	scrubLayoutMap(MVMap<String, String> meta)
private void	serializeAndStore(boolean syncRun, ArrayList<Page<?, ?>> changed, long time, long version)
private void	serializeToBuffer(WriteBuffer buff, ArrayList<Page<?, ?>> changed, C c, C previousChunk)
public final void	setAutoCommitDelay(int the maximum delay millis) Set the maximum delay in milliseconds to auto-commit changes.
public void	setCacheSize(int the cache size in MB. mb) Set the read cache size in MB.
protected final void	setLastChunk(C last)
public final void	setRetentionTime(int how many milliseconds to retain old chunks (0 to overwrite them as early as possible) ms) How long to retain old, persisted chunks, in milliseconds.
public void	setReuseSpace(boolean reuseSpace)
protected final void	setSize(long size)
public abstract boolean	Returns: true if commit should happen now shouldSaveNow(int amount of unsaved memory, so far unsavedMemory, int configured limit on amount of unsaved memory autoCommitMemory) Decision about autocommit is delegated to store
protected abstract void	shrinkStoreIfPossible(int the minimum percentage to save minPercent) Shrink store if possible, and if at least a given percentage can be saved.
private void	shutdownExecutors()
public long	Returns: the file size size() Get the file size.
public MVMap<String, String>	start()
public final void	stop(long allowedCompactionTime)
private void	stopBackgroundThread(boolean waitForIt)
protected final void	store()
private void	storeBuffer(C c, WriteBuffer buff)
pack-priv final void	storeIt(ArrayList<Page<?, ?>> changed, long version, boolean syncWrite)
private static int	submitOrRun(ThreadPoolExecutor executor, Runnable action, boolean syncRun, int threshold, int hwm)
public void	sync()
protected abstract boolean	validateFileLength(String msg)
protected abstract void	writeChunk(C chunk to write chunk, WriteBuffer to write buffer) Write buffer associated with chunk into store at chunk's allocated position
protected void	writeCleanShutdown()
protected abstract void	writeCleanShutdownMark() Performs final preparation before store is closed normally
protected abstract void	writeFully(C to write chunk, long the write position pos, ByteBuffer the source buffer src) Write to the file.
pack-priv void	writeInBackground() Commit and save all changes, if there are any, and compact the store if needed.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

public abstract Class FileStore<C extends Chunk<C>>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary