H2 Database Engine 2.3.232 · org.h2.mvstore.MVStore · APIdia, the JavaDoc alternative

Modifier and Type	Class and Description
public static class	MVStore.Builder A builder for an MVStore.
public static class	MVStore.TxCounter Class TxCounter is a simple data structure to hold version of the store along with the counter of open transactions, which are still operating on this version.

Field Summary

Modifier and Type	Field and Description
private final int	autoCommitMemory
public final Thread.UncaughtExceptionHandler	backgroundExceptionHandler
private final int	compressionLevel The compression level for new pages (0 for disabled, 1 for fast, 2 for high).
private Compressor	compressorFast
private Compressor	compressorHigh
private volatile MVStore.TxCounter	currentTxCounter Counter of open transactions for the latest (current) store version
private volatile long	currentVersion
private final FileStore<?>	fileStore
private final boolean	fileStoreShallBeClosed
pack-priv static final long	INITIAL_VERSION This designates the "last stored" version for a store which was just open for the first time.
private final int	keysPerPage
private final AtomicInteger	lastMapId
private long	lastTimeAbsolute
private long	leafCount
private final ConcurrentHashMap<Integer, MVMap<?, ?>>	maps
private final MVMap<String, String>	meta The metadata map.
private volatile boolean	metaChanged
private long	nonLeafCount
private final AtomicLong	oldestVersionToKeep Oldest store version in use.
private volatile LongConsumer	oldestVersionTracker Callback for maintenance after some unused store versions were dropped
private volatile MVStoreException	panicException
private volatile boolean	saveNeeded
private volatile int	state
private static final int	STATE_CLOSED Store is closed.
private static final int	STATE_OPEN Store is open.
private static final int	STATE_STOPPING Store is about to close now, but is still operational.
private final ReentrantLock	storeLock Lock which governs access to major store operations: store(), close(), ...
private final AtomicBoolean	storeOperationInProgress Flag to refine the state under storeLock.
private int	unsavedMemory The estimated memory used by unsaved pages.
private long	updateAttemptCounter
private long	updateCounter
private final Deque<MVStore.TxCounter>	versions Ordered collection of all version usage counters for all versions starting from oldestVersionToKeep and up to current.
private int	versionsToKeep

Access	Constructor and Description
pack-priv	MVStore(Map<String, Object> the configuration to use config) Create and open the store.

Method Summary

Modifier and Type	Method and Description
pack-priv 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.
pack-priv void	adjustLastMapId(int mapId)
pack-priv void	beforeWrite(MVMap<?, ?> the map map) This method is called before writing to a map.
private boolean	canStartStoreOperation()
private void	checkNotClosed()
private void	checkOpen()
public void	close() Implements java.lang.AutoCloseable.close. Close the file and the store.
public void	close(int time (in milliseconds) allotted for file compaction activity, 0 means no compaction, -1 means unlimited time (full compaction) allowedCompactionTime) Close the store.
public void	closeImmediately() Close the file and the store, without writing anything.
private void	closeStore(boolean normalShutdown, int allowedCompactionTime)
private ArrayList<Page<?, ?>>	collectChangedMapRoots(long version)
public long	Returns: the new version (incremented if there were changes) or -1 if there were no commit commit() Commit the changes.
private long	commit(Predicate<MVStore> check)
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.
public void	compactFile(int the maximum time in milliseconds to compact maxCompactTime) Compact store file, that is, compact blocks that have a low fill rate, and move chunks next to each other.
public void	countNewPage(boolean leaf)
public boolean	Returns: true if counter reaches zero, which indicates that version is no longer in use, false otherwise. decrementVersionUsageCounter(MVStore.TxCounter to be decremented, obtained from registerVersionUsage() txCounter) De-register (close) completed operation (transaction).
pack-priv void	deregisterMapRoot(int to deregister mapId) Performs final stage of map removal - delete root location info from the layout table.
public void	deregisterVersionUsage(MVStore.TxCounter to be decremented, obtained from registerVersionUsage() txCounter) De-register (close) completed operation (transaction).
private void	dropUnusedVersions()
public void	executeFilestoreOperation(Runnable operation)
public int	Returns: the delay in milliseconds, or 0 if auto-commit is disabled. getAutoCommitDelay() Get the auto-commit delay.
public int	Returns: the memory in bytes getAutoCommitMemory() Get the maximum memory (in bytes) used for unsaved pages.
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.
pack-priv int	getCompressionLevel()
pack-priv Compressor	getCompressorFast()
pack-priv Compressor	getCompressorHigh()
public long	Returns: the version getCurrentVersion() Get the current version of the data.
public FileStore<?>	Returns: the file store getFileStore() Get the file store.
public int	getFillRate()
public int	getKeysPerPage()
pack-priv int	getLastMapId()
public Map<String, String>	Returns: the metadata map getLayoutMap() Get this store's layout map.
private int	getLeafRatio()
public < the key type K, the value type V> MVMap<K, V>	Returns: Map getMap(int map id id) Get map by id.
private int	getMapId(String name)
public String	Returns: the name, or null if not found getMapName(int the map id id) Get the name of the given map.
public Set<String>	Returns: the set of names getMapNames() Get the set of all map names.
public long	getMaxPageSize()
public MVMap<String, String>	Returns: the metadata map getMetaMap() Get the metadata map.
private int	getNextMapId()
pack-priv long	Returns: the version getOldestVersionToKeep() Get the oldest version to retain.
public MVStoreException	getPanicException()
public int	getRetentionTime()
private long	getRootPos(int mapId)
public Map<String, Object>	Returns: the store header getStoreHeader() Get the store header.
public int	Returns: the store version getStoreVersion() Get the store version.
public long	getTimeAbsolute()
public int	Returns: the memory in bytes getUnsavedMemory() Get the estimated memory (in bytes) of unsaved data.
private double	getUpdateFailureRatio()
public long	Returns: the version getVersionsToKeep() Get the oldest version to retain in memory (for in-memory stores).
pack-priv boolean	handleException(Throwable ex)
public boolean	Returns: true if it exists and has data. hasData(String the map name name) Check whether a given map exists and has data.
public boolean	Returns: true if it exists hasMap(String the map name name) Check whether a given map exists.
public boolean	Returns: if there are any changes hasUnsavedChanges() Check whether there are any unsaved changes.
public boolean	Returns: true if store is open, false otherwise isClosed() Determine that store is open, or wait for it to be closed (by other thread)
private boolean	Returns: true if all data can be read isKnownVersion(long the version version) Check whether all data can be read from this version.
pack-priv boolean	isOpen()
private boolean	isOpenOrStopping()
public boolean	Returns: true if persistent isPersistent() Indicates whether this MVStore is backed by FileStore, and therefore it's data will survive this store closure (but not necessary process termination in case of in-memory store).
public boolean	Returns: true if it is isReadOnly() Whether the store is read-only.
private boolean	isRegularMap(MVMap<?, ?> map)
public boolean	isSpaceReused()
public boolean	Returns: true if versions are rolling, false otherwise isVersioningRequired() Indicates whether store versions are rolling.
pack-priv void	markMetaChanged()
private boolean	needStore()
pack-priv void	onVersionChange(long version)
public static MVStore	Returns: the store open(String the file name (null for in-memory) fileName) Open a store in exclusive mode.
public < the key type K, the value type V> MVMap<K, V>	Returns: the map openMap(String the name of the map name) Open a map with the default settings.
public < the map type M extends MVMap<K, V>, the key type K, the value type V> M	Returns: the map openMap(String the name of the map name, MVMap.MapBuilder<M, K, V> the map builder builder) Open a map with the given builder.
public < the map type M extends MVMap<K, V>, the key type K, the value type V> M	Returns: the map openMap(int the map id id, MVMap.MapBuilder<M, K, V> the map builder builder) Open an existing map with the given builder.
public MVMap<String, String>	openMetaMap()
public void	panic(MVStoreException e)
public void	populateInfo(BiConsumer<String, String> consumer)
pack-priv < key type K, value type V> Page<K, V>	Returns: the page readPage(MVMap<K, V> the map map, long the page position pos) Read a page.
public void	registerUnsavedMemory(int adjustment memory) Adjust amount of "unsaved memory" meaning amount of RAM occupied by pages not saved yet to the file.
pack-priv void	registerUnsavedMemoryAndCommitIfNeeded(int memory)
public MVStore.TxCounter	Returns: TxCounter to be decremented when operation finishes (transaction closed). registerVersionUsage() Register opened operation (transaction).
public void	removeMap(MVMap<?, ?> the map to remove map) Remove a map from the current version of the store.
public void	removeMap(String the map name name) Remove map by name.
public void	renameMap(MVMap<?, ?> the map map, String the new name newName) Rename a map.
private boolean	requireStore()
pack-priv void	resetLastMapId(int mapId)
public void	rollback() Revert to the beginning of the current version, reverting all uncommitted changes.
public void	rollbackTo(long the version to revert to version) Revert to the beginning of the given version.
private void	scrubMetaMap()
public void	setAutoCommitDelay(int the maximum delay millis) Set the maximum delay in milliseconds to auto-commit changes.
public void	setCacheSize(int the maximum size in KB kb) Set the maximum memory to be used by the cache.
pack-priv void	setCurrentVersion(long curVersion)
private void	setOldestVersionToKeep(long version)
public void	setOldestVersionTracker(LongConsumer callback)
public 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 the new value reuseSpace) Whether empty space in the file should be re-used.
public void	setStoreVersion(int the new store version version) Update the store version.
public void	setVersionsToKeep(int the number of versions to keep count) How many versions to retain for in-memory stores.
private void	setWriteVersion(long version)
private long	store(boolean syncWrite)
pack-priv void	storeNow()
private void	storeNow(boolean syncWrite)
public void	sync() Force all stored changes to be written to the storage.
public long	Returns: the new version (incremented if there were changes) or -1 if there were no commit tryCommit() Unlike regular commit this method returns immediately if there is commit in progress on another thread, otherwise it acts as regular commit.
private long	tryCommit(Predicate<MVStore> check)
pack-priv <R> R	tryExecuteUnderStoreLock(Callable<R> operation)
private void	unlockAndCheckPanicCondition()

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

public final Class MVStore

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary