/// <summary> /// Merge some number of blocks, how many is decided by mergeFactor, into a single sorted block. This is done by opening <seealso cref="BlockEntryReader"/> on each /// block that we want to merge and give them to a <seealso cref="MergingBlockEntryReader"/>. The <seealso cref="BlockEntryReader"/>s are pulled from a <seealso cref="BlockReader"/> /// that iterate over Blocks in file in sequential order. /// /// <seealso cref="MergingBlockEntryReader"/> pull head from each <seealso cref="BlockEntryReader"/> and hand them out in sorted order, making the multiple entry readers look /// like a single large and sorted entry reader. /// /// The large block resulting from the merge is written down to targetChannel by calling /// <seealso cref="writeBlock(StoreChannel, BlockEntryCursor, long, long, Cancellation, IntConsumer, ByteBuffer)"/>. /// </summary> /// <param name="mergeFactor"> How many blocks to merge at the same time. Influence how much memory will be used because each merge block will have it's own /// <seealso cref="ByteBuffer"/> that they read from. </param> /// <param name="reader"> The <seealso cref="BlockReader"/> to pull blocks / <seealso cref="BlockEntryReader"/>s from. </param> /// <param name="targetChannel"> The <seealso cref="StoreChannel"/> to write the merge result to. Result will be appended to current position. </param> /// <param name="cancellation"> Injected so that this merge can be cancelled, if an external request to do that comes in. </param> /// <param name="readBuffers"> buffers for all block readers. </param> /// <param name="writeBuffer"> buffer for writing merged blocks. </param> /// <returns> The number of blocks that where merged, most often this will be equal to mergeFactor but can be less if there are fewer blocks left in source. </returns> /// <exception cref="IOException"> If something goes wrong when reading from file. </exception> //JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#: //ORIGINAL LINE: private int performSingleMerge(int mergeFactor, BlockReader<KEY,VALUE> reader, org.neo4j.io.fs.StoreChannel targetChannel, Cancellation cancellation, ByteBuffer[] readBuffers, ByteBuffer writeBuffer) throws java.io.IOException private int PerformSingleMerge(int mergeFactor, BlockReader <KEY, VALUE> reader, StoreChannel targetChannel, Cancellation cancellation, ByteBuffer[] readBuffers, ByteBuffer writeBuffer) { using (MergingBlockEntryReader <KEY, VALUE> merger = new MergingBlockEntryReader <KEY, VALUE>(_layout)) { long blockSize = 0; long entryCount = 0; int blocksMerged = 0; for (int i = 0; i < mergeFactor; i++) { readBuffers[i].clear(); BlockEntryReader <KEY, VALUE> source = reader.NextBlock(readBuffers[i]); if (source != null) { blockSize += source.BlockSize(); entryCount += source.EntryCount(); blocksMerged++; merger.AddSource(source); } else { break; } } writeBuffer.clear(); WriteBlock(targetChannel, merger, blockSize, entryCount, cancellation, _monitor.entriesMerged, writeBuffer); _monitor.mergedBlocks(blockSize, entryCount, blocksMerged); return(blocksMerged); } }
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#: //ORIGINAL LINE: private void writeScanUpdatesToTree(RecordingConflictDetector<KEY,VALUE> recordingConflictDetector, org.neo4j.kernel.impl.index.schema.ByteBufferFactory.Allocator allocator, int bufferSize) throws java.io.IOException, org.neo4j.kernel.api.exceptions.index.IndexEntryConflictException private void WriteScanUpdatesToTree(RecordingConflictDetector <KEY, VALUE> recordingConflictDetector, Allocator allocator, int bufferSize) { using (MergingBlockEntryReader <KEY, VALUE> allEntries = new MergingBlockEntryReader <KEY, VALUE>(layout)) { ByteBuffer singleBlockAssertionBuffer = allocator.Allocate(( int )kibiBytes(8)); foreach (ThreadLocalBlockStorage part in _allScanUpdates) { using (BlockReader <KEY, VALUE> reader = part.BlockStorage.reader()) { BlockEntryReader <KEY, VALUE> singleMergedBlock = reader.NextBlock(allocator.Allocate(bufferSize)); if (singleMergedBlock != null) { allEntries.AddSource(singleMergedBlock); // Pass in some sort of ByteBuffer here. The point is that there should be no more data to read, // if there is then it's due to a bug in the code and must be fixed. if (reader.NextBlock(singleBlockAssertionBuffer) != null) { throw new System.InvalidOperationException("Final BlockStorage had multiple blocks"); } } } } int asMuchAsPossibleToTheLeft = 1; using (Writer <KEY, VALUE> writer = tree.writer(asMuchAsPossibleToTheLeft)) { while (allEntries.Next() && !_cancellation.cancelled()) { WriteToTree(writer, recordingConflictDetector, allEntries.Key(), allEntries.Value()); _numberOfAppliedScanUpdates++; } } } }
/// <summary> /// There are two files: sourceFile and targetFile. Blocks are merged, mergeFactor at the time, from source to target. When all blocks from source have /// been merged into a larger block one merge iteration is done and source and target are flipped. As long as source contain more than a single block more /// merge iterations are needed and we start over again. /// When source only contain a single block we are finished and the extra file is deleted and <seealso cref="blockFile"/> contains the result with a single sorted /// block. /// /// See <seealso cref="performSingleMerge(int, BlockReader, StoreChannel, Cancellation, ByteBuffer[], ByteBuffer)"/> for further details. /// </summary> /// <param name="mergeFactor"> See <seealso cref="performSingleMerge(int, BlockReader, StoreChannel, Cancellation, ByteBuffer[], ByteBuffer)"/>. </param> /// <param name="cancellation"> Injected so that this merge can be cancelled, if an external request to do that comes in. /// A cancelled merge will leave the same end state file/channel-wise, just not quite completed, which is fine because the merge /// was cancelled meaning that the result will not be used for anything other than deletion. </param> /// <exception cref="IOException"> If something goes wrong when reading from file. </exception> //JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#: //ORIGINAL LINE: public void merge(int mergeFactor, Cancellation cancellation) throws java.io.IOException public virtual void Merge(int mergeFactor, Cancellation cancellation) { _monitor.mergeStarted(_entryCount, CalculateNumberOfEntriesWrittenDuringMerges(_entryCount, _numberOfBlocksInCurrentFile, mergeFactor)); File sourceFile = _blockFile; File tempFile = new File(_blockFile.Parent, _blockFile.Name + ".b"); try { using (Allocator mergeBufferAllocator = _bufferFactory.newLocalAllocator()) { File targetFile = tempFile; // Allocate all buffers that will be used and reused for all merge iterations ByteBuffer writeBuffer = mergeBufferAllocator.Allocate(_bufferFactory.bufferSize()); ByteBuffer[] readBuffers = new ByteBuffer[mergeFactor]; for (int i = 0; i < readBuffers.Length; i++) { readBuffers[i] = mergeBufferAllocator.Allocate(_bufferFactory.bufferSize()); } while (_numberOfBlocksInCurrentFile > 1) { // Perform one complete merge iteration, merging all blocks from source into target. // After this step, target will contain fewer blocks than source, but may need another merge iteration. using (BlockReader <KEY, VALUE> reader = reader(sourceFile), StoreChannel targetChannel = _fs.open(targetFile, OpenMode.READ_WRITE)) { long blocksMergedSoFar = 0; long blocksInMergedFile = 0; while (!cancellation.Cancelled() && blocksMergedSoFar < _numberOfBlocksInCurrentFile) { blocksMergedSoFar += PerformSingleMerge(mergeFactor, reader, targetChannel, cancellation, readBuffers, writeBuffer); blocksInMergedFile++; } _numberOfBlocksInCurrentFile = blocksInMergedFile; _monitor.mergeIterationFinished(blocksMergedSoFar, blocksInMergedFile); } // Flip and restore the channels File tmpSourceFile = sourceFile; sourceFile = targetFile; targetFile = tmpSourceFile; } } } finally { if (sourceFile == _blockFile) { _fs.deleteFile(tempFile); } else { _fs.deleteFile(_blockFile); _fs.renameFile(tempFile, _blockFile); } } }
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#: //ORIGINAL LINE: private void assertContents(org.neo4j.index.internal.gbptree.SimpleLongLayout layout, BlockStorage<org.apache.commons.lang3.mutable.MutableLong,org.apache.commons.lang3.mutable.MutableLong> storage, Iterable<java.util.List<BlockEntry<org.apache.commons.lang3.mutable.MutableLong,org.apache.commons.lang3.mutable.MutableLong>>> expectedBlocks) throws java.io.IOException private void AssertContents(SimpleLongLayout layout, BlockStorage <MutableLong, MutableLong> storage, IEnumerable <IList <BlockEntry <MutableLong, MutableLong> > > expectedBlocks) { using (BlockReader <MutableLong, MutableLong> reader = storage.Reader()) { foreach (IList <BlockEntry <MutableLong, MutableLong> > expectedBlock in expectedBlocks) { using (BlockEntryReader <MutableLong, MutableLong> block = reader.NextBlock(HEAP_ALLOCATOR.allocate(1024))) { assertNotNull(block); assertEquals(expectedBlock.Count, block.EntryCount()); foreach (BlockEntry <MutableLong, MutableLong> expectedEntry in expectedBlock) { assertTrue(block.Next()); assertEquals(0, layout.Compare(expectedEntry.Key(), block.Key())); assertEquals(expectedEntry.Value(), block.Value()); } } } } }