Package org.eclipse.jgit.internal.storage.reftable

Class ReftableReader

java.lang.Object

org.eclipse.jgit.internal.storage.reftable.Reftable

org.eclipse.jgit.internal.storage.reftable.ReftableReader

All Implemented Interfaces:

java.lang.AutoCloseable

public class ReftableReader
extends Reftable
implements java.lang.AutoCloseable

Reads a reftable formatted file.

ReftableReader is not thread-safe. Concurrent readers need their own instance to read from the same file.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	ReftableReader.LogCursorImpl
private class	ReftableReader.ObjCursorImpl
private class	ReftableReader.RefCursorImpl

Field Summary

Fields

Modifier and Type	Field	Description
private int	blockSize
(package private) static LongList	EMPTY_LONG_LIST
private LongMap<BlockReader>	indexCache
private long	logEnd
private BlockReader	logIndex
private long	logIndexPosition
private long	logPosition
private long	maxUpdateIndex
private long	minUpdateIndex
private long	objEnd
private int	objIdLen
private BlockReader	objIndex
private long	objIndexPosition
private long	objPosition
private long	refEnd
private BlockReader	refIndex
private long	refIndexPosition
private BlockSource	src

Fields inherited from class org.eclipse.jgit.internal.storage.reftable.Reftable

includeDeletes

Constructor Summary

Constructors

Constructor	Description
ReftableReader(BlockSource src)	Initialize a new reftable reader.

Method Summary

Modifier and Type	Method	Description
LogCursor	allLogs()	Seek reader to read log records.
RefCursor	allRefs()	Seek to the first reference, to iterate in order.
private BlockReader	binarySearch(byte blockType, byte[] key, long startPos, long endPos)
private int	blocksIn(long pos, long end)
int	blockSize()	Get the block size in bytes chosen for this file by the writer.
RefCursor	byObjectId(AnyObjectId id)	Match references pointing to a specific object.
void	close()
boolean	hasObjectMap()
private void	initLogIndex()
private void	initObjIndex()
private void	initRefIndex()
long	maxUpdateIndex()	Get the maximum update index for ref entries that appear in this reftable.
long	minUpdateIndex()	Get the minimum update index for ref entries that appear in this reftable.
private BlockReader	readBlock(long pos, long end)
private int	readBlockLen(long pos)
private void	readFileFooter()
private void	readFileHeader()
private byte[]	readHeaderOrFooter(long pos, int len)
private BlockReader	readIndex(long pos)
private BlockReader	seek(byte blockType, byte[] key, BlockReader idx, long startPos, long endPos)
LogCursor	seekLog(java.lang.String refName, long updateIndex)	Seek to an update index in a reference's log.
RefCursor	seekRef(java.lang.String refName)	Seek to a reference.
RefCursor	seekRefsWithPrefix(java.lang.String prefix)	Seek references with prefix.
long	size()	Get size of the reftable, in bytes.

Methods inherited from class org.eclipse.jgit.internal.storage.reftable.Reftable

exactRef, from, hasId, hasRef, hasRefsWithPrefix, resolve, seekLog, setIncludeDeletes

Methods inherited from class java.lang.Object

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

Field Detail

src

private final BlockSource src

blockSize

private int blockSize

minUpdateIndex

private long minUpdateIndex

maxUpdateIndex

private long maxUpdateIndex

refEnd

private long refEnd

objPosition

private long objPosition

objEnd

private long objEnd

logPosition

private long logPosition

logEnd

private long logEnd

objIdLen

private int objIdLen

refIndexPosition

private long refIndexPosition

objIndexPosition

private long objIndexPosition

logIndexPosition

private long logIndexPosition

refIndex

private BlockReader refIndex

objIndex

private BlockReader objIndex

logIndex

private BlockReader logIndex

indexCache

private LongMap<BlockReader> indexCache

EMPTY_LONG_LIST

static final LongList EMPTY_LONG_LIST

Constructor Detail

ReftableReader

public ReftableReader(BlockSource src)

Initialize a new reftable reader.

Parameters:

src - the file content to read.

Method Detail

blockSize

public int blockSize()
              throws java.io.IOException

Get the block size in bytes chosen for this file by the writer.

Returns:

the block size in bytes chosen for this file by the writer. Most reads from the BlockSource will be aligned to the block size.

Throws:

java.io.IOException - file cannot be read.

hasObjectMap

public boolean hasObjectMap()
                     throws java.io.IOException

Specified by:

hasObjectMap in class Reftable

Returns:

whether this reftable can do a fast SHA1 => ref lookup.

Throws:

java.io.IOException - on I/O problems.

minUpdateIndex

public long minUpdateIndex()
                    throws java.io.IOException

Get the minimum update index for ref entries that appear in this reftable.

Specified by:

minUpdateIndex in class Reftable

Returns:

the minimum update index for ref entries that appear in this reftable.

Throws:

java.io.IOException - file cannot be read.

maxUpdateIndex

public long maxUpdateIndex()
                    throws java.io.IOException

Get the maximum update index for ref entries that appear in this reftable.

Specified by:

maxUpdateIndex in class Reftable

Returns:

the maximum update index for ref entries that appear in this reftable.

Throws:

java.io.IOException - file cannot be read.

allRefs

public RefCursor allRefs()
                  throws java.io.IOException

Seek to the first reference, to iterate in order.

Specified by:

allRefs in class Reftable

Returns:

cursor to iterate.

Throws:

java.io.IOException - if references cannot be read.

seekRef

public RefCursor seekRef(java.lang.String refName)
                  throws java.io.IOException

Seek to a reference.

This method will seek to the reference refName. If present, the returned cursor will iterate exactly one entry. If not found, an empty cursor is returned.

Specified by:

seekRef in class Reftable

Parameters:

refName - reference name.

Returns:

cursor to iterate; empty cursor if no references match.

Throws:

java.io.IOException - if references cannot be read.

seekRefsWithPrefix

public RefCursor seekRefsWithPrefix(java.lang.String prefix)
                             throws java.io.IOException

Seek references with prefix.

The method will seek all the references starting with prefix as a prefix. If no references start with this prefix, an empty cursor is returned.

Specified by:

seekRefsWithPrefix in class Reftable

Parameters:

prefix - prefix to find.

Returns:

cursor to iterate; empty cursor if no references match.

Throws:

java.io.IOException - if references cannot be read.

byObjectId

public RefCursor byObjectId(AnyObjectId id)
                     throws java.io.IOException

Match references pointing to a specific object.

Specified by:

byObjectId in class Reftable

Parameters:

id - object to find.

Returns:

cursor to iterate; empty cursor if no references match.

Throws:

java.io.IOException - if references cannot be read.

allLogs

public LogCursor allLogs()
                  throws java.io.IOException

Seek reader to read log records.

Specified by:

allLogs in class Reftable

Returns:

cursor to iterate; empty cursor if no logs are present.

Throws:

java.io.IOException - if logs cannot be read.

seekLog

public LogCursor seekLog(java.lang.String refName,
                         long updateIndex)
                  throws java.io.IOException

Seek to an update index in a reference's log.

Specified by:

seekLog in class Reftable

Parameters:

refName - exact name of the reference whose log to read.

updateIndex - most recent index to return first in the log cursor. Log records at or before updateIndex will be returned.

Returns:

cursor to iterate; empty cursor if no logs match.

Throws:

java.io.IOException - if logs cannot be read.

seek

private BlockReader seek(byte blockType,
                         byte[] key,
                         BlockReader idx,
                         long startPos,
                         long endPos)
                  throws java.io.IOException

Throws:

java.io.IOException

binarySearch

private BlockReader binarySearch(byte blockType,
                                 byte[] key,
                                 long startPos,
                                 long endPos)
                          throws java.io.IOException

Throws:

java.io.IOException

readFileHeader

private void readFileHeader()
                     throws java.io.IOException

Throws:

java.io.IOException

readFileFooter

private void readFileFooter()
                     throws java.io.IOException

Throws:

java.io.IOException

readHeaderOrFooter

private byte[] readHeaderOrFooter(long pos,
                                  int len)
                           throws java.io.IOException

Throws:

java.io.IOException

initRefIndex

private void initRefIndex()
                   throws java.io.IOException

Throws:

java.io.IOException

initObjIndex

private void initObjIndex()
                   throws java.io.IOException

Throws:

java.io.IOException

initLogIndex

private void initLogIndex()
                   throws java.io.IOException

Throws:

java.io.IOException

readIndex

private BlockReader readIndex(long pos)
                       throws java.io.IOException

Throws:

java.io.IOException

readBlockLen

private int readBlockLen(long pos)
                  throws java.io.IOException

Throws:

java.io.IOException

readBlock

private BlockReader readBlock(long pos,
                              long end)
                       throws java.io.IOException

Throws:

java.io.IOException

blocksIn

private int blocksIn(long pos,
                     long end)

size

public long size()
          throws java.io.IOException

Get size of the reftable, in bytes.

Returns:

size of the reftable, in bytes.

Throws:

java.io.IOException - size cannot be obtained.

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException