org.apache.ignite.internal.processors.cache.persistence.wal

Class AbstractWalRecordsIterator

java.lang.Object

org.apache.ignite.internal.util.lang.GridIteratorAdapter<T>

org.apache.ignite.internal.util.GridCloseableIteratorAdapter<IgniteBiTuple<WALPointer,WALRecord>>

org.apache.ignite.internal.processors.cache.persistence.wal.AbstractWalRecordsIterator

All Implemented Interfaces:

Serializable, AutoCloseable, Iterable<IgniteBiTuple<WALPointer,WALRecord>>, Iterator<IgniteBiTuple<WALPointer,WALRecord>>, WALIterator, GridSerializableIterator<IgniteBiTuple<WALPointer,WALRecord>>, GridCloseableIterator<IgniteBiTuple<WALPointer,WALRecord>>, GridIterator<IgniteBiTuple<WALPointer,WALRecord>>, IgniteSpiCloseableIterator<IgniteBiTuple<WALPointer,WALRecord>>

Direct Known Subclasses:

SingleSegmentLogicalRecordsIterator

public abstract class AbstractWalRecordsIterator
extends GridCloseableIteratorAdapter<IgniteBiTuple<WALPointer,WALRecord>>
implements WALIterator

Iterator over WAL segments. This abstract class provides most functionality for reading records in log. Subclasses are to override segment switching functionality

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static interface	AbstractWalRecordsIterator.AbstractFileDescriptor
protected static interface	AbstractWalRecordsIterator.AbstractReadFileHandle

Field Summary

Fields

Modifier and Type	Field and Description
protected IgniteBiTuple<WALPointer,WALRecord>	curRec Current record preloaded, to be returned on next() Normally this should be not null because advance() method should already prepare some value
protected long	curWalSegmIdx Current WAL segment absolute index.
protected FileIOFactory	ioFactory Factory to provide I/O interfaces for read/write operations with files
protected IgniteLogger	log Logger
protected GridCacheSharedContext	sharedCtx Shared context for creating serializer of required version and grid name access.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractWalRecordsIterator(IgniteLogger log, GridCacheSharedContext sharedCtx, RecordSerializerFactory serializerFactory, FileIOFactory ioFactory, int bufSize)

Method Summary

Modifier and Type	Method and Description
protected void	advance() Switches records iterator to the next record.
protected abstract AbstractWalRecordsIterator.AbstractReadFileHandle	advanceSegment(AbstractWalRecordsIterator.AbstractReadFileHandle curWalSegment) Switches records iterator to the next WAL segment as result of this method, new reference to segment should be returned.
protected AbstractWalRecordsIterator.AbstractReadFileHandle	closeCurrentWalSegment() Closes and returns WAL segment (if any)
protected abstract AbstractWalRecordsIterator.AbstractReadFileHandle	createReadFileHandle(FileIO fileIO, long idx, RecordSerializer ser, FileInput in)
protected void	handleRecordException(Exception e, FileWALPointer ptr) Handler for record deserialization exception
protected AbstractWalRecordsIterator.AbstractReadFileHandle	initReadHandle(AbstractWalRecordsIterator.AbstractFileDescriptor desc, FileWALPointer start)
protected void	onClose() Invoked on iterator close.
protected boolean	onHasNext()
protected IgniteBiTuple<WALPointer,WALRecord>	onNext()
protected WALRecord	postProcessRecord(WALRecord rec) Performs final conversions with record loaded from WAL.

Methods inherited from class org.apache.ignite.internal.util.GridCloseableIteratorAdapter

checkClosed, close, hasNextX, isClosed, nextX, onRemove, removeX

Methods inherited from class org.apache.ignite.internal.util.lang.GridIteratorAdapter

hasNext, iterator, next, remove

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ignite.internal.util.lang.GridCloseableIterator

close, isClosed

Methods inherited from interface org.apache.ignite.internal.util.lang.GridIterator

hasNextX, nextX, removeX

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Methods inherited from interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Field Detail

curRec

protected IgniteBiTuple<WALPointer,WALRecord> curRec

Current record preloaded, to be returned on next()
Normally this should be not null because advance() method should already prepare some value

curWalSegmIdx

protected long curWalSegmIdx

Current WAL segment absolute index.
Determined as lowest number of file at start, is changed during advance segment

log

@NotNull
protected final IgniteLogger log

Logger

sharedCtx

@NotNull
protected final GridCacheSharedContext sharedCtx

Shared context for creating serializer of required version and grid name access. Also cacheObjects processor from this context may be used to covert Data entry key and value from its binary representation into objects.

ioFactory

@NotNull
protected final FileIOFactory ioFactory

Factory to provide I/O interfaces for read/write operations with files

Constructor Detail

AbstractWalRecordsIterator

protected AbstractWalRecordsIterator(@NotNull
                                     IgniteLogger log,
                                     @NotNull
                                     GridCacheSharedContext sharedCtx,
                                     @NotNull
                                     RecordSerializerFactory serializerFactory,
                                     @NotNull
                                     FileIOFactory ioFactory,
                                     int bufSize)

Parameters:

log - Logger.

sharedCtx - Shared context.

serializerFactory - Serializer of current version to read headers.

ioFactory - ioFactory for file IO access.

bufSize - buffer for reading records size.

Method Detail

onNext

protected IgniteBiTuple<WALPointer,WALRecord> onNext()
                                              throws IgniteCheckedException

Specified by:

onNext in class GridCloseableIteratorAdapter<IgniteBiTuple<WALPointer,WALRecord>>

Returns:

Next element.

Throws:

IgniteCheckedException - If failed.

onHasNext

protected boolean onHasNext()
                     throws IgniteCheckedException

Specified by:

onHasNext in class GridCloseableIteratorAdapter<IgniteBiTuple<WALPointer,WALRecord>>

Returns:

True if iterator has next element.

Throws:

IgniteCheckedException - If failed.

onClose

protected void onClose()
                throws IgniteCheckedException

Invoked on iterator close.

Overrides:

onClose in class GridCloseableIteratorAdapter<IgniteBiTuple<WALPointer,WALRecord>>

Throws:

IgniteCheckedException - If closing failed.

advance

protected void advance()
                throws IgniteCheckedException

Switches records iterator to the next record.

• curRec will be updated.
• If end of segment reached, switch to new segment is called. currWalSegment will be updated.

advance() runs a step ahead GridIteratorAdapter.next()

Throws:

IgniteCheckedException - If failed.

closeCurrentWalSegment

@Nullable
protected AbstractWalRecordsIterator.AbstractReadFileHandle closeCurrentWalSegment()
                                                                                      throws IgniteCheckedException

Closes and returns WAL segment (if any)

Returns:

closed handle

Throws:

IgniteCheckedException - if IO failed

advanceSegment

protected abstract AbstractWalRecordsIterator.AbstractReadFileHandle advanceSegment(@Nullable
                                                                                    AbstractWalRecordsIterator.AbstractReadFileHandle curWalSegment)
                                                                             throws IgniteCheckedException

Switches records iterator to the next WAL segment as result of this method, new reference to segment should be returned. Null for current handle means stop of iteration

Parameters:

curWalSegment - current open WAL segment or null if there is no open segment yet

Returns:

new WAL segment to read or null for stop iteration

Throws:

IgniteCheckedException - if reading failed

postProcessRecord

@NotNull
protected WALRecord postProcessRecord(@NotNull
                                               WALRecord rec)

Performs final conversions with record loaded from WAL. To be overridden by subclasses if any processing required.

Parameters:

rec - record to post process.

Returns:

post processed record.

handleRecordException

protected void handleRecordException(@NotNull
                                     Exception e,
                                     @Nullable
                                     FileWALPointer ptr)

Handler for record deserialization exception

Parameters:

e - problem from records reading

ptr - file pointer was accessed

initReadHandle

protected AbstractWalRecordsIterator.AbstractReadFileHandle initReadHandle(@NotNull
                                                                           AbstractWalRecordsIterator.AbstractFileDescriptor desc,
                                                                           @Nullable
                                                                           FileWALPointer start)
                                                                    throws IgniteCheckedException,
                                                                           FileNotFoundException

Parameters:

desc - File descriptor.

start - Optional start pointer. Null means read from the beginning

Returns:

Initialized file handle.

Throws:

FileNotFoundException - If segment file is missing.

IgniteCheckedException - If initialized failed due to another unexpected error.

createReadFileHandle

protected abstract AbstractWalRecordsIterator.AbstractReadFileHandle createReadFileHandle(FileIO fileIO,
                                                                                          long idx,
                                                                                          RecordSerializer ser,
                                                                                          FileInput in)