Package org.eclipse.jgit.internal.storage.file

Class FileReftableStack

java.lang.Object

org.eclipse.jgit.internal.storage.file.FileReftableStack

All Implemented Interfaces:

java.lang.AutoCloseable

public class FileReftableStack
extends java.lang.Object
implements java.lang.AutoCloseable

A mutable stack of reftables on local filesystem storage. Not thread-safe. This is an AutoCloseable because this object owns the file handles to the open reftables.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	FileReftableStack.CompactionStats
static class	FileReftableStack.ReftableNumbersNotIncreasingException	Thrown if the update indices in the stack are not monotonic
(package private) static class	FileReftableStack.Segment	A segment is a consecutive list of reftables of the same approximate size.
private static class	FileReftableStack.StackEntry
static interface	FileReftableStack.Writer	Writer is a callable that writes data to a reftable under construction.

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.function.Supplier<Config>	configSupplier
private long	lastNextUpdateIndex
private MergedReftable	mergedReftable
private java.lang.Runnable	onChange
private static long	OVERHEAD
private java.security.SecureRandom	random
private java.io.File	reftableDir
private java.util.List<FileReftableStack.StackEntry>	stack
private java.io.File	stackPath
private FileReftableStack.CompactionStats	stats

Constructor Summary

Constructors

Constructor	Description
FileReftableStack(java.io.File stackPath, java.io.File reftableDir, java.lang.Runnable onChange, java.util.function.Supplier<Config> configSupplier)	Creates a stack corresponding to the list of reftables in the argument

Method Summary

Modifier and Type	Method	Description
boolean	addReftable(FileReftableStack.Writer w)	Tries to add a new reftable to the stack.
private void	autoCompact()	Heuristically tries to compact the stack if the stack has a suitable shape.
private static java.util.Optional<FileReftableStack.Segment>	autoCompactCandidate(long[] sizes)
void	close()
(package private) void	compactFully()
private java.io.File	compactLocked(int first, int last)	Write the reftable for the given range into a temp file.
(package private) boolean	compactRange(int first, int last)	Compacts a range of the stack, following the file locking protocol documented in the spec.
private java.lang.String	filename(long low, long high)
MergedReftable	getMergedReftable()
(package private) FileReftableStack.CompactionStats	getStats()
(package private) boolean	isUpToDate()
(package private) static int	log(long sz)	Calculate an approximate log2.
private long	nextUpdateIndex()
private java.util.List<java.lang.String>	readTableNames()
private ReftableConfig	reftableConfig()
(package private) void	reload()
private void	reloadOnce(java.util.List<java.lang.String> names)	Reloads the stack, potentially reusing opened reftableReaders.
(package private) static java.util.List<FileReftableStack.Segment>	segmentSizes(long[] sizes)
private long[]	tableSizes()

Methods inherited from class java.lang.Object

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

Field Detail

mergedReftable

private MergedReftable mergedReftable

stack

private java.util.List<FileReftableStack.StackEntry> stack

lastNextUpdateIndex

private long lastNextUpdateIndex

stackPath

private final java.io.File stackPath

reftableDir

private final java.io.File reftableDir

onChange

private final java.lang.Runnable onChange

random

private final java.security.SecureRandom random

configSupplier

private final java.util.function.Supplier<Config> configSupplier

stats

private final FileReftableStack.CompactionStats stats

OVERHEAD

private static long OVERHEAD

Constructor Detail

FileReftableStack

public FileReftableStack(java.io.File stackPath,
                         java.io.File reftableDir,
                         @Nullable
                         java.lang.Runnable onChange,
                         java.util.function.Supplier<Config> configSupplier)
                  throws java.io.IOException

Creates a stack corresponding to the list of reftables in the argument

Parameters:

stackPath - the filename for the stack.

reftableDir - the dir holding the tables.

onChange - hook to call if we notice a new write

configSupplier - Config supplier

Throws:

java.io.IOException - on I/O problems

Method Detail

getStats

FileReftableStack.CompactionStats getStats()

reloadOnce

private void reloadOnce(java.util.List<java.lang.String> names)
                 throws java.io.IOException,
                        java.io.FileNotFoundException

Reloads the stack, potentially reusing opened reftableReaders.

Parameters:

names - holds the names of the tables to load.

Throws:

java.io.FileNotFoundException - load must be retried.

java.io.IOException - on other IO errors.

reload

void reload()
     throws java.io.IOException

Throws:

java.io.IOException

getMergedReftable

public MergedReftable getMergedReftable()

Returns:

the merged reftable

readTableNames

private java.util.List<java.lang.String> readTableNames()
                                                 throws java.io.IOException

Throws:

java.io.IOException

isUpToDate

boolean isUpToDate()
            throws java.io.IOException

Returns:

true if the on-disk file corresponds to the in-memory data.

Throws:

java.io.IOException - on IO problem

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

nextUpdateIndex

private long nextUpdateIndex()
                      throws java.io.IOException

Throws:

java.io.IOException

filename

private java.lang.String filename(long low,
                                  long high)

addReftable

public boolean addReftable(FileReftableStack.Writer w)
                    throws java.io.IOException

Tries to add a new reftable to the stack. Returns true if it succeeded, or false if there was a lock failure, due to races with other processes. This is package private so FileReftableDatabase can call into here.

Parameters:

w - writer to write data to a reftable under construction

Returns:

true if the transaction was successful.

Throws:

java.io.IOException - on I/O problems

reftableConfig

private ReftableConfig reftableConfig()

compactLocked

private java.io.File compactLocked(int first,
                                   int last)
                            throws java.io.IOException

Write the reftable for the given range into a temp file.

Parameters:

first - index of first stack entry to be written

last - index of last stack entry to be written

Returns:

the file holding the replacement table.

Throws:

java.io.IOException - on I/O problem

compactRange

boolean compactRange(int first,
                     int last)
              throws java.io.IOException

Compacts a range of the stack, following the file locking protocol documented in the spec.

Parameters:

first - index of first stack entry to be considered in compaction

last - index of last stack entry to be considered in compaction

Returns:

true if a compaction was successfully applied.

Throws:

java.io.IOException - on I/O problem

log

static int log(long sz)

Calculate an approximate log2.

Parameters:

sz -

Returns:

log2

segmentSizes

static java.util.List<FileReftableStack.Segment> segmentSizes(long[] sizes)

autoCompactCandidate

private static java.util.Optional<FileReftableStack.Segment> autoCompactCandidate(long[] sizes)

autoCompact

private void autoCompact()
                  throws java.io.IOException

Heuristically tries to compact the stack if the stack has a suitable shape.

Throws:

java.io.IOException

tableSizes

private long[] tableSizes()
                   throws java.io.IOException

Throws:

java.io.IOException

compactFully

void compactFully()
           throws java.io.IOException

Throws:

java.io.IOException