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apache / hbase / 6cdc4b1f0574cc424480ec2f2e3129f280fa8472 / . / hbase-server / src / main / java / org / apache / hadoop / hbase / io / hfile / HFileReaderImpl.java
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.io.hfile;
import java.io.DataInput;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Optional;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.ByteBufferKeyOnlyKeyValue;
import org.apache.hadoop.hbase.ByteBufferKeyValue;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellComparator;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.NoTagsByteBufferKeyValue;
import org.apache.hadoop.hbase.PrivateCellUtil;
import org.apache.hadoop.hbase.SizeCachedKeyValue;
import org.apache.hadoop.hbase.SizeCachedNoTagsKeyValue;
import org.apache.hadoop.hbase.io.compress.Compression;
import org.apache.hadoop.hbase.io.encoding.DataBlockEncoder;
import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDecodingContext;
import org.apache.hadoop.hbase.nio.ByteBuff;
import org.apache.hadoop.hbase.regionserver.KeyValueScanner;
import org.apache.hadoop.hbase.trace.TraceUtil;
import org.apache.hadoop.hbase.util.ByteBufferUtils;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.IdLock;
import org.apache.hadoop.hbase.util.ObjectIntPair;
import org.apache.hadoop.io.WritableUtils;
import org.apache.htrace.core.TraceScope;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;
/**
* Implementation that can handle all hfile versions of {@link HFile.Reader}.
*/
@InterfaceAudience.Private
@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
public abstract class HFileReaderImpl implements HFile.Reader, Configurable {
// This class is HFileReaderV3 + HFileReaderV2 + AbstractHFileReader all squashed together into
// one file. Ditto for all the HFileReader.ScannerV? implementations. I was running up against
// the MaxInlineLevel limit because too many tiers involved reading from an hfile. Was also hard
// to navigate the source code when so many classes participating in read.
private static final Logger LOG = LoggerFactory.getLogger(HFileReaderImpl.class);
/** Data block index reader keeping the root data index in memory */
protected HFileBlockIndex.CellBasedKeyBlockIndexReader dataBlockIndexReader;
/** Meta block index reader -- always single level */
protected HFileBlockIndex.ByteArrayKeyBlockIndexReader metaBlockIndexReader;
protected FixedFileTrailer trailer;
private final boolean primaryReplicaReader;
/**
* What kind of data block encoding should be used while reading, writing,
* and handling cache.
*/
protected HFileDataBlockEncoder dataBlockEncoder = NoOpDataBlockEncoder.INSTANCE;
/** Block cache configuration. */
protected final CacheConfig cacheConf;
protected ReaderContext context;
protected final HFileInfo fileInfo;
/** Path of file */
protected final Path path;
/** File name to be used for block names */
protected final String name;
private Configuration conf;
protected HFileContext hfileContext;
/** Filesystem-level block reader. */
protected HFileBlock.FSReader fsBlockReader;
/**
* A "sparse lock" implementation allowing to lock on a particular block
* identified by offset. The purpose of this is to avoid two clients loading
* the same block, and have all but one client wait to get the block from the
* cache.
*/
private IdLock offsetLock = new IdLock();
/** Minimum minor version supported by this HFile format */
static final int MIN_MINOR_VERSION = 0;
/** Maximum minor version supported by this HFile format */
// We went to version 2 when we moved to pb'ing fileinfo and the trailer on
// the file. This version can read Writables version 1.
static final int MAX_MINOR_VERSION = 3;
/** Minor versions starting with this number have faked index key */
static final int MINOR_VERSION_WITH_FAKED_KEY = 3;
/**
* Opens a HFile.
* @param context Reader context info
* @param fileInfo HFile info
* @param cacheConf Cache configuration.
* @param conf Configuration
*/
@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
public HFileReaderImpl(ReaderContext context, HFileInfo fileInfo, CacheConfig cacheConf,
Configuration conf) throws IOException {
this.cacheConf = cacheConf;
this.context = context;
this.path = context.getFilePath();
this.name = path.getName();
this.conf = conf;
this.primaryReplicaReader = context.isPrimaryReplicaReader();
this.fileInfo = fileInfo;
this.trailer = fileInfo.getTrailer();
this.hfileContext = fileInfo.getHFileContext();
this.fsBlockReader = new HFileBlock.FSReaderImpl(context, hfileContext,
cacheConf.getByteBuffAllocator());
this.dataBlockEncoder = HFileDataBlockEncoderImpl.createFromFileInfo(fileInfo);
fsBlockReader.setDataBlockEncoder(dataBlockEncoder);
dataBlockIndexReader = fileInfo.getDataBlockIndexReader();
metaBlockIndexReader = fileInfo.getMetaBlockIndexReader();
}
@SuppressWarnings("serial")
public static class BlockIndexNotLoadedException extends IllegalStateException {
public BlockIndexNotLoadedException(Path path) {
// Add a message in case anyone relies on it as opposed to class name.
super(path + " block index not loaded");
}
}
private Optional<String> toStringFirstKey() {
return getFirstKey().map(CellUtil::getCellKeyAsString);
}
private Optional<String> toStringLastKey() {
return getLastKey().map(CellUtil::getCellKeyAsString);
}
@Override
public String toString() {
return "reader=" + path.toString() +
(!isFileInfoLoaded()? "":
", compression=" + trailer.getCompressionCodec().getName() +
", cacheConf=" + cacheConf +
", firstKey=" + toStringFirstKey() +
", lastKey=" + toStringLastKey()) +
", avgKeyLen=" + fileInfo.getAvgKeyLen() +
", avgValueLen=" + fileInfo.getAvgValueLen() +
", entries=" + trailer.getEntryCount() +
", length=" + context.getFileSize();
}
@Override
public long length() {
return context.getFileSize();
}
/**
* @return the first key in the file. May be null if file has no entries. Note
* that this is not the first row key, but rather the byte form of the
* first KeyValue.
*/
@Override
public Optional<Cell> getFirstKey() {
if (dataBlockIndexReader == null) {
throw new BlockIndexNotLoadedException(path);
}
return dataBlockIndexReader.isEmpty() ? Optional.empty()
: Optional.of(dataBlockIndexReader.getRootBlockKey(0));
}
/**
* TODO left from {@link HFile} version 1: move this to StoreFile after Ryan's
* patch goes in to eliminate {@link KeyValue} here.
*
* @return the first row key, or null if the file is empty.
*/
@Override
public Optional<byte[]> getFirstRowKey() {
// We have to copy the row part to form the row key alone
return getFirstKey().map(CellUtil::cloneRow);
}
/**
* TODO left from {@link HFile} version 1: move this to StoreFile after
* Ryan's patch goes in to eliminate {@link KeyValue} here.
*
* @return the last row key, or null if the file is empty.
*/
@Override
public Optional<byte[]> getLastRowKey() {
// We have to copy the row part to form the row key alone
return getLastKey().map(CellUtil::cloneRow);
}
/** @return number of KV entries in this HFile */
@Override
public long getEntries() {
return trailer.getEntryCount();
}
/** @return comparator */
@Override
public CellComparator getComparator() {
return this.hfileContext.getCellComparator();
}
@VisibleForTesting
public Compression.Algorithm getCompressionAlgorithm() {
return trailer.getCompressionCodec();
}
/**
* @return the total heap size of data and meta block indexes in bytes. Does
* not take into account non-root blocks of a multilevel data index.
*/
@Override
public long indexSize() {
return (dataBlockIndexReader != null ? dataBlockIndexReader.heapSize() : 0)
+ ((metaBlockIndexReader != null) ? metaBlockIndexReader.heapSize()
: 0);
}
@Override
public String getName() {
return name;
}
@Override
public void setDataBlockEncoder(HFileDataBlockEncoder dataBlockEncoder) {
this.dataBlockEncoder = dataBlockEncoder;
this.fsBlockReader.setDataBlockEncoder(dataBlockEncoder);
}
@Override
public void setDataBlockIndexReader(HFileBlockIndex.CellBasedKeyBlockIndexReader reader) {
this.dataBlockIndexReader = reader;
}
@Override
public HFileBlockIndex.CellBasedKeyBlockIndexReader getDataBlockIndexReader() {
return dataBlockIndexReader;
}
@Override
public void setMetaBlockIndexReader(HFileBlockIndex.ByteArrayKeyBlockIndexReader reader) {
this.metaBlockIndexReader = reader;
}
@Override
public HFileBlockIndex.ByteArrayKeyBlockIndexReader getMetaBlockIndexReader() {
return metaBlockIndexReader;
}
@Override
public FixedFileTrailer getTrailer() {
return trailer;
}
@Override
public ReaderContext getContext() {
return this.context;
}
@Override
public HFileInfo getHFileInfo() {
return this.fileInfo;
}
@Override
public boolean isPrimaryReplicaReader() {
return primaryReplicaReader;
}
/**
* An exception thrown when an operation requiring a scanner to be seeked
* is invoked on a scanner that is not seeked.
*/
@SuppressWarnings("serial")
public static class NotSeekedException extends IllegalStateException {
public NotSeekedException(Path path) {
super(path + " not seeked to a key/value");
}
}
protected static class HFileScannerImpl implements HFileScanner {
private ByteBuff blockBuffer;
protected final boolean cacheBlocks;
protected final boolean pread;
protected final boolean isCompaction;
private int currKeyLen;
private int currValueLen;
private int currMemstoreTSLen;
private long currMemstoreTS;
protected final HFile.Reader reader;
private int currTagsLen;
// buffer backed keyonlyKV
private ByteBufferKeyOnlyKeyValue bufBackedKeyOnlyKv = new ByteBufferKeyOnlyKeyValue();
// A pair for reusing in blockSeek() so that we don't garbage lot of objects
final ObjectIntPair<ByteBuffer> pair = new ObjectIntPair<>();
/**
* The next indexed key is to keep track of the indexed key of the next data block.
* If the nextIndexedKey is HConstants.NO_NEXT_INDEXED_KEY, it means that the
* current data block is the last data block.
*
* If the nextIndexedKey is null, it means the nextIndexedKey has not been loaded yet.
*/
protected Cell nextIndexedKey;
// Current block being used. NOTICE: DON't release curBlock separately except in shipped() or
// close() methods. Because the shipped() or close() will do the release finally, even if any
// exception occur the curBlock will be released by the close() method (see
// RegionScannerImpl#handleException). Call the releaseIfNotCurBlock() to release the
// unreferenced block please.
protected HFileBlock curBlock;
// Previous blocks that were used in the course of the read
protected final ArrayList<HFileBlock> prevBlocks = new ArrayList<>();
public HFileScannerImpl(final HFile.Reader reader, final boolean cacheBlocks,
final boolean pread, final boolean isCompaction) {
this.reader = reader;
this.cacheBlocks = cacheBlocks;
this.pread = pread;
this.isCompaction = isCompaction;
}
void updateCurrBlockRef(HFileBlock block) {
if (block != null && curBlock != null && block.getOffset() == curBlock.getOffset()) {
return;
}
if (this.curBlock != null && this.curBlock.isSharedMem()) {
prevBlocks.add(this.curBlock);
}
this.curBlock = block;
}
void reset() {
// We don't have to keep ref to heap block
if (this.curBlock != null && this.curBlock.isSharedMem()) {
this.prevBlocks.add(this.curBlock);
}
this.curBlock = null;
}
private void returnBlocks(boolean returnAll) {
this.prevBlocks.forEach(HFileBlock::release);
this.prevBlocks.clear();
if (returnAll && this.curBlock != null) {
this.curBlock.release();
this.curBlock = null;
}
}
@Override
public boolean isSeeked(){
return blockBuffer != null;
}
@Override
public String toString() {
return "HFileScanner for reader " + String.valueOf(getReader());
}
protected void assertSeeked() {
if (!isSeeked()) {
throw new NotSeekedException(reader.getPath());
}
}
@Override
public HFile.Reader getReader() {
return reader;
}
// From non encoded HFiles, we always read back KeyValue or its descendant.(Note: When HFile
// block is in DBB, it will be OffheapKV). So all parts of the Cell is in a contiguous
// array/buffer. How many bytes we should wrap to make the KV is what this method returns.
private int getKVBufSize() {
int kvBufSize = KEY_VALUE_LEN_SIZE + currKeyLen + currValueLen;
if (currTagsLen > 0) {
kvBufSize += Bytes.SIZEOF_SHORT + currTagsLen;
}
return kvBufSize;
}
@Override
public void close() {
if (!pread) {
// For seek + pread stream socket should be closed when the scanner is closed. HBASE-9393
reader.unbufferStream();
}
this.returnBlocks(true);
}
// Returns the #bytes in HFile for the current cell. Used to skip these many bytes in current
// HFile block's buffer so as to position to the next cell.
private int getCurCellSerializedSize() {
int curCellSize = KEY_VALUE_LEN_SIZE + currKeyLen + currValueLen
+ currMemstoreTSLen;
if (this.reader.getFileContext().isIncludesTags()) {
curCellSize += Bytes.SIZEOF_SHORT + currTagsLen;
}
return curCellSize;
}
protected void readKeyValueLen() {
// This is a hot method. We go out of our way to make this method short so it can be
// inlined and is not too big to compile. We also manage position in ByteBuffer ourselves
// because it is faster than going via range-checked ByteBuffer methods or going through a
// byte buffer array a byte at a time.
// Get a long at a time rather than read two individual ints. In micro-benchmarking, even
// with the extra bit-fiddling, this is order-of-magnitude faster than getting two ints.
// Trying to imitate what was done - need to profile if this is better or
// earlier way is better by doing mark and reset?
// But ensure that you read long instead of two ints
long ll = blockBuffer.getLongAfterPosition(0);
// Read top half as an int of key length and bottom int as value length
this.currKeyLen = (int)(ll >> Integer.SIZE);
this.currValueLen = (int)(Bytes.MASK_FOR_LOWER_INT_IN_LONG ^ ll);
checkKeyValueLen();
// Move position past the key and value lengths and then beyond the key and value
int p = (Bytes.SIZEOF_LONG + currKeyLen + currValueLen);
if (reader.getFileContext().isIncludesTags()) {
// Tags length is a short.
this.currTagsLen = blockBuffer.getShortAfterPosition(p);
checkTagsLen();
p += (Bytes.SIZEOF_SHORT + currTagsLen);
}
readMvccVersion(p);
}
private final void checkTagsLen() {
if (checkLen(this.currTagsLen)) {
throw new IllegalStateException("Invalid currTagsLen " + this.currTagsLen +
". Block offset: " + curBlock.getOffset() + ", block length: " +
this.blockBuffer.limit() +
", position: " + this.blockBuffer.position() + " (without header)." +
" path=" + reader.getPath());
}
}
/**
* Read mvcc. Does checks to see if we even need to read the mvcc at all.
*/
protected void readMvccVersion(final int offsetFromPos) {
// See if we even need to decode mvcc.
if (!this.reader.getHFileInfo().shouldIncludeMemStoreTS()) {
return;
}
if (!this.reader.getHFileInfo().isDecodeMemstoreTS()) {
currMemstoreTS = 0;
currMemstoreTSLen = 1;
return;
}
_readMvccVersion(offsetFromPos);
}
/**
* Actually do the mvcc read. Does no checks.
*/
private void _readMvccVersion(int offsetFromPos) {
// This is Bytes#bytesToVint inlined so can save a few instructions in this hot method; i.e.
// previous if one-byte vint, we'd redo the vint call to find int size.
// Also the method is kept small so can be inlined.
byte firstByte = blockBuffer.getByteAfterPosition(offsetFromPos);
int len = WritableUtils.decodeVIntSize(firstByte);
if (len == 1) {
this.currMemstoreTS = firstByte;
} else {
int remaining = len -1;
long i = 0;
offsetFromPos++;
if (remaining >= Bytes.SIZEOF_INT) {
// The int read has to be converted to unsigned long so the & op
i = (blockBuffer.getIntAfterPosition(offsetFromPos) & 0x00000000ffffffffL);
remaining -= Bytes.SIZEOF_INT;
offsetFromPos += Bytes.SIZEOF_INT;
}
if (remaining >= Bytes.SIZEOF_SHORT) {
short s = blockBuffer.getShortAfterPosition(offsetFromPos);
i = i << 16;
i = i | (s & 0xFFFF);
remaining -= Bytes.SIZEOF_SHORT;
offsetFromPos += Bytes.SIZEOF_SHORT;
}
for (int idx = 0; idx < remaining; idx++) {
byte b = blockBuffer.getByteAfterPosition(offsetFromPos + idx);
i = i << 8;
i = i | (b & 0xFF);
}
currMemstoreTS = (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
}
this.currMemstoreTSLen = len;
}
/**
* Within a loaded block, seek looking for the last key that is smaller than
* (or equal to?) the key we are interested in.
* A note on the seekBefore: if you have seekBefore = true, AND the first
* key in the block = key, then you'll get thrown exceptions. The caller has
* to check for that case and load the previous block as appropriate.
* @param key
* the key to find
* @param seekBefore
* find the key before the given key in case of exact match.
* @return 0 in case of an exact key match, 1 in case of an inexact match,
* -2 in case of an inexact match and furthermore, the input key
* less than the first key of current block(e.g. using a faked index
* key)
*/
protected int blockSeek(Cell key, boolean seekBefore) {
int klen, vlen, tlen = 0;
int lastKeyValueSize = -1;
int offsetFromPos;
do {
offsetFromPos = 0;
// Better to ensure that we use the BB Utils here
long ll = blockBuffer.getLongAfterPosition(offsetFromPos);
klen = (int)(ll >> Integer.SIZE);
vlen = (int)(Bytes.MASK_FOR_LOWER_INT_IN_LONG ^ ll);
if (checkKeyLen(klen) || checkLen(vlen)) {
throw new IllegalStateException("Invalid klen " + klen + " or vlen "
+ vlen + ". Block offset: "
+ curBlock.getOffset() + ", block length: " + blockBuffer.limit() + ", position: "
+ blockBuffer.position() + " (without header)."
+ " path=" + reader.getPath());
}
offsetFromPos += Bytes.SIZEOF_LONG;
blockBuffer.asSubByteBuffer(blockBuffer.position() + offsetFromPos, klen, pair);
bufBackedKeyOnlyKv.setKey(pair.getFirst(), pair.getSecond(), klen);
int comp =
PrivateCellUtil.compareKeyIgnoresMvcc(reader.getComparator(), key, bufBackedKeyOnlyKv);
offsetFromPos += klen + vlen;
if (this.reader.getFileContext().isIncludesTags()) {
// Read short as unsigned, high byte first
tlen = ((blockBuffer.getByteAfterPosition(offsetFromPos) & 0xff) << 8)
^ (blockBuffer.getByteAfterPosition(offsetFromPos + 1) & 0xff);
if (checkLen(tlen)) {
throw new IllegalStateException("Invalid tlen " + tlen + ". Block offset: "
+ curBlock.getOffset() + ", block length: " + blockBuffer.limit() + ", position: "
+ blockBuffer.position() + " (without header)."
+ " path=" + reader.getPath());
}
// add the two bytes read for the tags.
offsetFromPos += tlen + (Bytes.SIZEOF_SHORT);
}
if (this.reader.getHFileInfo().shouldIncludeMemStoreTS()) {
// Directly read the mvcc based on current position
readMvccVersion(offsetFromPos);
}
if (comp == 0) {
if (seekBefore) {
if (lastKeyValueSize < 0) {
throw new IllegalStateException("blockSeek with seekBefore "
+ "at the first key of the block: key=" + CellUtil.getCellKeyAsString(key)
+ ", blockOffset=" + curBlock.getOffset() + ", onDiskSize="
+ curBlock.getOnDiskSizeWithHeader()
+ ", path=" + reader.getPath());
}
blockBuffer.moveBack(lastKeyValueSize);
readKeyValueLen();
return 1; // non exact match.
}
currKeyLen = klen;
currValueLen = vlen;
currTagsLen = tlen;
return 0; // indicate exact match
} else if (comp < 0) {
if (lastKeyValueSize > 0) {
blockBuffer.moveBack(lastKeyValueSize);
}
readKeyValueLen();
if (lastKeyValueSize == -1 && blockBuffer.position() == 0) {
return HConstants.INDEX_KEY_MAGIC;
}
return 1;
}
// The size of this key/value tuple, including key/value length fields.
lastKeyValueSize = klen + vlen + currMemstoreTSLen + KEY_VALUE_LEN_SIZE;
// include tag length also if tags included with KV
if (reader.getFileContext().isIncludesTags()) {
lastKeyValueSize += tlen + Bytes.SIZEOF_SHORT;
}
blockBuffer.skip(lastKeyValueSize);
} while (blockBuffer.hasRemaining());
// Seek to the last key we successfully read. This will happen if this is
// the last key/value pair in the file, in which case the following call
// to next() has to return false.
blockBuffer.moveBack(lastKeyValueSize);
readKeyValueLen();
return 1; // didn't exactly find it.
}
@Override
public Cell getNextIndexedKey() {
return nextIndexedKey;
}
@Override
public int seekTo(Cell key) throws IOException {
return seekTo(key, true);
}
@Override
public int reseekTo(Cell key) throws IOException {
int compared;
if (isSeeked()) {
compared = compareKey(reader.getComparator(), key);
if (compared < 1) {
// If the required key is less than or equal to current key, then
// don't do anything.
return compared;
} else {
// The comparison with no_next_index_key has to be checked
if (this.nextIndexedKey != null &&
(this.nextIndexedKey == KeyValueScanner.NO_NEXT_INDEXED_KEY || PrivateCellUtil
.compareKeyIgnoresMvcc(reader.getComparator(), key, nextIndexedKey) < 0)) {
// The reader shall continue to scan the current data block instead
// of querying the
// block index as long as it knows the target key is strictly
// smaller than
// the next indexed key or the current data block is the last data
// block.
return loadBlockAndSeekToKey(this.curBlock, nextIndexedKey, false, key,
false);
}
}
}
// Don't rewind on a reseek operation, because reseek implies that we are
// always going forward in the file.
return seekTo(key, false);
}
/**
* An internal API function. Seek to the given key, optionally rewinding to
* the first key of the block before doing the seek.
*
* @param key - a cell representing the key that we need to fetch
* @param rewind whether to rewind to the first key of the block before
* doing the seek. If this is false, we are assuming we never go
* back, otherwise the result is undefined.
* @return -1 if the key is earlier than the first key of the file,
* 0 if we are at the given key, 1 if we are past the given key
* -2 if the key is earlier than the first key of the file while
* using a faked index key
*/
public int seekTo(Cell key, boolean rewind) throws IOException {
HFileBlockIndex.BlockIndexReader indexReader = reader.getDataBlockIndexReader();
BlockWithScanInfo blockWithScanInfo = indexReader.loadDataBlockWithScanInfo(key, curBlock,
cacheBlocks, pread, isCompaction, getEffectiveDataBlockEncoding(), reader);
if (blockWithScanInfo == null || blockWithScanInfo.getHFileBlock() == null) {
// This happens if the key e.g. falls before the beginning of the file.
return -1;
}
return loadBlockAndSeekToKey(blockWithScanInfo.getHFileBlock(),
blockWithScanInfo.getNextIndexedKey(), rewind, key, false);
}
@Override
public boolean seekBefore(Cell key) throws IOException {
HFileBlock seekToBlock = reader.getDataBlockIndexReader().seekToDataBlock(key, curBlock,
cacheBlocks, pread, isCompaction, reader.getEffectiveEncodingInCache(isCompaction),
reader);
if (seekToBlock == null) {
return false;
}
Cell firstKey = getFirstKeyCellInBlock(seekToBlock);
if (PrivateCellUtil.compareKeyIgnoresMvcc(reader.getComparator(), firstKey, key) >= 0) {
long previousBlockOffset = seekToBlock.getPrevBlockOffset();
// The key we are interested in
if (previousBlockOffset == -1) {
// we have a 'problem', the key we want is the first of the file.
releaseIfNotCurBlock(seekToBlock);
return false;
}
// The first key in the current block 'seekToBlock' is greater than the given
// seekBefore key. We will go ahead by reading the next block that satisfies the
// given key. Return the current block before reading the next one.
releaseIfNotCurBlock(seekToBlock);
// It is important that we compute and pass onDiskSize to the block
// reader so that it does not have to read the header separately to
// figure out the size. Currently, we do not have a way to do this
// correctly in the general case however.
// TODO: See https://issues.apache.org/jira/browse/HBASE-14576
int prevBlockSize = -1;
seekToBlock = reader.readBlock(previousBlockOffset, prevBlockSize, cacheBlocks, pread,
isCompaction, true, BlockType.DATA, getEffectiveDataBlockEncoding());
// TODO shortcut: seek forward in this block to the last key of the
// block.
}
loadBlockAndSeekToKey(seekToBlock, firstKey, true, key, true);
return true;
}
/**
* The curBlock will be released by shipping or close method, so only need to consider releasing
* the block, which was read from HFile before and not referenced by curBlock.
*/
protected void releaseIfNotCurBlock(HFileBlock block) {
if (curBlock != block) {
block.release();
}
}
/**
* Scans blocks in the "scanned" section of the {@link HFile} until the next
* data block is found.
*
* @return the next block, or null if there are no more data blocks
*/
@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="NP_NULL_ON_SOME_PATH",
justification="Yeah, unnecessary null check; could do w/ clean up")
protected HFileBlock readNextDataBlock() throws IOException {
long lastDataBlockOffset = reader.getTrailer().getLastDataBlockOffset();
if (curBlock == null) {
return null;
}
HFileBlock block = this.curBlock;
do {
if (block.getOffset() >= lastDataBlockOffset) {
releaseIfNotCurBlock(block);
return null;
}
if (block.getOffset() < 0) {
releaseIfNotCurBlock(block);
throw new IOException("Invalid block offset: " + block + ", path=" + reader.getPath());
}
// We are reading the next block without block type validation, because
// it might turn out to be a non-data block.
block = reader.readBlock(block.getOffset() + block.getOnDiskSizeWithHeader(),
block.getNextBlockOnDiskSize(), cacheBlocks, pread, isCompaction, true, null,
getEffectiveDataBlockEncoding());
if (block != null && !block.getBlockType().isData()) {
// Whatever block we read we will be returning it unless
// it is a datablock. Just in case the blocks are non data blocks
block.release();
}
} while (!block.getBlockType().isData());
return block;
}
public DataBlockEncoding getEffectiveDataBlockEncoding() {
return this.reader.getEffectiveEncodingInCache(isCompaction);
}
@Override
public Cell getCell() {
if (!isSeeked()) {
return null;
}
Cell ret;
int cellBufSize = getKVBufSize();
long seqId = 0L;
if (this.reader.getHFileInfo().shouldIncludeMemStoreTS()) {
seqId = currMemstoreTS;
}
if (blockBuffer.hasArray()) {
// TODO : reduce the varieties of KV here. Check if based on a boolean
// we can handle the 'no tags' case.
if (currTagsLen > 0) {
ret = new SizeCachedKeyValue(blockBuffer.array(),
blockBuffer.arrayOffset() + blockBuffer.position(), cellBufSize, seqId);
} else {
ret = new SizeCachedNoTagsKeyValue(blockBuffer.array(),
blockBuffer.arrayOffset() + blockBuffer.position(), cellBufSize, seqId);
}
} else {
ByteBuffer buf = blockBuffer.asSubByteBuffer(cellBufSize);
if (buf.isDirect()) {
ret = currTagsLen > 0 ? new ByteBufferKeyValue(buf, buf.position(), cellBufSize, seqId)
: new NoTagsByteBufferKeyValue(buf, buf.position(), cellBufSize, seqId);
} else {
if (currTagsLen > 0) {
ret = new SizeCachedKeyValue(buf.array(), buf.arrayOffset() + buf.position(),
cellBufSize, seqId);
} else {
ret = new SizeCachedNoTagsKeyValue(buf.array(), buf.arrayOffset() + buf.position(),
cellBufSize, seqId);
}
}
}
return ret;
}
@Override
public Cell getKey() {
assertSeeked();
// Create a new object so that this getKey is cached as firstKey, lastKey
ObjectIntPair<ByteBuffer> keyPair = new ObjectIntPair<>();
blockBuffer.asSubByteBuffer(blockBuffer.position() + KEY_VALUE_LEN_SIZE, currKeyLen, keyPair);
ByteBuffer keyBuf = keyPair.getFirst();
if (keyBuf.hasArray()) {
return new KeyValue.KeyOnlyKeyValue(keyBuf.array(), keyBuf.arrayOffset()
+ keyPair.getSecond(), currKeyLen);
} else {
// Better to do a copy here instead of holding on to this BB so that
// we could release the blocks referring to this key. This key is specifically used
// in HalfStoreFileReader to get the firstkey and lastkey by creating a new scanner
// every time. So holding onto the BB (incase of DBB) is not advised here.
byte[] key = new byte[currKeyLen];
ByteBufferUtils.copyFromBufferToArray(key, keyBuf, keyPair.getSecond(), 0, currKeyLen);
return new KeyValue.KeyOnlyKeyValue(key, 0, currKeyLen);
}
}
@Override
public ByteBuffer getValue() {
assertSeeked();
// Okie to create new Pair. Not used in hot path
ObjectIntPair<ByteBuffer> valuePair = new ObjectIntPair<>();
this.blockBuffer.asSubByteBuffer(blockBuffer.position() + KEY_VALUE_LEN_SIZE + currKeyLen,
currValueLen, valuePair);
ByteBuffer valBuf = valuePair.getFirst().duplicate();
valBuf.position(valuePair.getSecond());
valBuf.limit(currValueLen + valuePair.getSecond());
return valBuf.slice();
}
protected void setNonSeekedState() {
reset();
blockBuffer = null;
currKeyLen = 0;
currValueLen = 0;
currMemstoreTS = 0;
currMemstoreTSLen = 0;
currTagsLen = 0;
}
/**
* Set the position on current backing blockBuffer.
*/
private void positionThisBlockBuffer() {
try {
blockBuffer.skip(getCurCellSerializedSize());
} catch (IllegalArgumentException e) {
LOG.error("Current pos = " + blockBuffer.position()
+ "; currKeyLen = " + currKeyLen + "; currValLen = "
+ currValueLen + "; block limit = " + blockBuffer.limit()
+ "; currBlock currBlockOffset = " + this.curBlock.getOffset()
+ "; path=" + reader.getPath());
throw e;
}
}
/**
* Set our selves up for the next 'next' invocation, set up next block.
* @return True is more to read else false if at the end.
*/
private boolean positionForNextBlock() throws IOException {
// Methods are small so they get inlined because they are 'hot'.
long lastDataBlockOffset = reader.getTrailer().getLastDataBlockOffset();
if (this.curBlock.getOffset() >= lastDataBlockOffset) {
setNonSeekedState();
return false;
}
return isNextBlock();
}
private boolean isNextBlock() throws IOException {
// Methods are small so they get inlined because they are 'hot'.
HFileBlock nextBlock = readNextDataBlock();
if (nextBlock == null) {
setNonSeekedState();
return false;
}
updateCurrentBlock(nextBlock);
return true;
}
private final boolean _next() throws IOException {
// Small method so can be inlined. It is a hot one.
if (blockBuffer.remaining() <= 0) {
return positionForNextBlock();
}
// We are still in the same block.
readKeyValueLen();
return true;
}
/**
* Go to the next key/value in the block section. Loads the next block if
* necessary. If successful, {@link #getKey()} and {@link #getValue()} can
* be called.
*
* @return true if successfully navigated to the next key/value
*/
@Override
public boolean next() throws IOException {
// This is a hot method so extreme measures taken to ensure it is small and inlineable.
// Checked by setting: -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlining -XX:+PrintCompilation
assertSeeked();
positionThisBlockBuffer();
return _next();
}
/**
* Positions this scanner at the start of the file.
*
* @return false if empty file; i.e. a call to next would return false and
* the current key and value are undefined.
*/
@Override
public boolean seekTo() throws IOException {
if (reader == null) {
return false;
}
if (reader.getTrailer().getEntryCount() == 0) {
// No data blocks.
return false;
}
long firstDataBlockOffset = reader.getTrailer().getFirstDataBlockOffset();
if (curBlock != null && curBlock.getOffset() == firstDataBlockOffset) {
return processFirstDataBlock();
}
readAndUpdateNewBlock(firstDataBlockOffset);
return true;
}
protected boolean processFirstDataBlock() throws IOException{
blockBuffer.rewind();
readKeyValueLen();
return true;
}
protected void readAndUpdateNewBlock(long firstDataBlockOffset) throws IOException {
HFileBlock newBlock = reader.readBlock(firstDataBlockOffset, -1, cacheBlocks, pread,
isCompaction, true, BlockType.DATA, getEffectiveDataBlockEncoding());
if (newBlock.getOffset() < 0) {
releaseIfNotCurBlock(newBlock);
throw new IOException("Invalid offset=" + newBlock.getOffset() +
", path=" + reader.getPath());
}
updateCurrentBlock(newBlock);
}
protected int loadBlockAndSeekToKey(HFileBlock seekToBlock, Cell nextIndexedKey, boolean rewind,
Cell key, boolean seekBefore) throws IOException {
if (this.curBlock == null || this.curBlock.getOffset() != seekToBlock.getOffset()) {
updateCurrentBlock(seekToBlock);
} else if (rewind) {
blockBuffer.rewind();
}
// Update the nextIndexedKey
this.nextIndexedKey = nextIndexedKey;
return blockSeek(key, seekBefore);
}
/**
* @return True if v &lt;= 0 or v &gt; current block buffer limit.
*/
protected final boolean checkKeyLen(final int v) {
return v <= 0 || v > this.blockBuffer.limit();
}
/**
* @return True if v &lt; 0 or v &gt; current block buffer limit.
*/
protected final boolean checkLen(final int v) {
return v < 0 || v > this.blockBuffer.limit();
}
/**
* Check key and value lengths are wholesome.
*/
protected final void checkKeyValueLen() {
if (checkKeyLen(this.currKeyLen) || checkLen(this.currValueLen)) {
throw new IllegalStateException("Invalid currKeyLen " + this.currKeyLen
+ " or currValueLen " + this.currValueLen + ". Block offset: "
+ this.curBlock.getOffset() + ", block length: "
+ this.blockBuffer.limit() + ", position: " + this.blockBuffer.position()
+ " (without header)." + ", path=" + reader.getPath());
}
}
/**
* Updates the current block to be the given {@link HFileBlock}. Seeks to the the first
* key/value pair.
* @param newBlock the block read by {@link HFileReaderImpl#readBlock}, it's a totally new block
* with new allocated {@link ByteBuff}, so if no further reference to this block, we
* should release it carefully.
*/
protected void updateCurrentBlock(HFileBlock newBlock) throws IOException {
try {
if (newBlock.getBlockType() != BlockType.DATA) {
throw new IllegalStateException(
"ScannerV2 works only on data blocks, got " + newBlock.getBlockType() + "; "
+ "HFileName=" + reader.getPath() + ", " + "dataBlockEncoder="
+ reader.getDataBlockEncoding() + ", " + "isCompaction=" + isCompaction);
}
updateCurrBlockRef(newBlock);
blockBuffer = newBlock.getBufferWithoutHeader();
readKeyValueLen();
} finally {
releaseIfNotCurBlock(newBlock);
}
// Reset the next indexed key
this.nextIndexedKey = null;
}
protected Cell getFirstKeyCellInBlock(HFileBlock curBlock) {
ByteBuff buffer = curBlock.getBufferWithoutHeader();
// It is safe to manipulate this buffer because we own the buffer object.
buffer.rewind();
int klen = buffer.getInt();
buffer.skip(Bytes.SIZEOF_INT);// Skip value len part
ByteBuffer keyBuff = buffer.asSubByteBuffer(klen);
if (keyBuff.hasArray()) {
return new KeyValue.KeyOnlyKeyValue(keyBuff.array(), keyBuff.arrayOffset()
+ keyBuff.position(), klen);
} else {
return new ByteBufferKeyOnlyKeyValue(keyBuff, keyBuff.position(), klen);
}
}
@Override
public String getKeyString() {
return CellUtil.toString(getKey(), false);
}
@Override
public String getValueString() {
return ByteBufferUtils.toStringBinary(getValue());
}
public int compareKey(CellComparator comparator, Cell key) {
blockBuffer.asSubByteBuffer(blockBuffer.position() + KEY_VALUE_LEN_SIZE, currKeyLen, pair);
this.bufBackedKeyOnlyKv.setKey(pair.getFirst(), pair.getSecond(), currKeyLen);
return PrivateCellUtil.compareKeyIgnoresMvcc(comparator, key, this.bufBackedKeyOnlyKv);
}
@Override
public void shipped() throws IOException {
this.returnBlocks(false);
}
}
@Override
public Path getPath() {
return path;
}
@Override
public DataBlockEncoding getDataBlockEncoding() {
return dataBlockEncoder.getDataBlockEncoding();
}
@Override
public Configuration getConf() {
return conf;
}
@Override
public void setConf(Configuration conf) {
this.conf = conf;
}
/** Minor versions in HFile starting with this number have hbase checksums */
public static final int MINOR_VERSION_WITH_CHECKSUM = 1;
/** In HFile minor version that does not support checksums */
public static final int MINOR_VERSION_NO_CHECKSUM = 0;
/** HFile minor version that introduced pbuf filetrailer */
public static final int PBUF_TRAILER_MINOR_VERSION = 2;
/**
* The size of a (key length, value length) tuple that prefixes each entry in
* a data block.
*/
public final static int KEY_VALUE_LEN_SIZE = 2 * Bytes.SIZEOF_INT;
/**
* Retrieve block from cache. Validates the retrieved block's type vs {@code expectedBlockType}
* and its encoding vs. {@code expectedDataBlockEncoding}. Unpacks the block as necessary.
*/
private HFileBlock getCachedBlock(BlockCacheKey cacheKey, boolean cacheBlock, boolean useLock,
boolean isCompaction, boolean updateCacheMetrics, BlockType expectedBlockType,
DataBlockEncoding expectedDataBlockEncoding) throws IOException {
// Check cache for block. If found return.
BlockCache cache = cacheConf.getBlockCache().orElse(null);
if (cache != null) {
HFileBlock cachedBlock =
(HFileBlock) cache.getBlock(cacheKey, cacheBlock, useLock, updateCacheMetrics);
if (cachedBlock != null) {
if (cacheConf.shouldCacheCompressed(cachedBlock.getBlockType().getCategory())) {
HFileBlock compressedBlock = cachedBlock;
cachedBlock = compressedBlock.unpack(hfileContext, fsBlockReader);
// In case of compressed block after unpacking we can release the compressed block
if (compressedBlock != cachedBlock) {
compressedBlock.release();
}
}
try {
validateBlockType(cachedBlock, expectedBlockType);
} catch (IOException e) {
returnAndEvictBlock(cache, cacheKey, cachedBlock);
throw e;
}
if (expectedDataBlockEncoding == null) {
return cachedBlock;
}
DataBlockEncoding actualDataBlockEncoding = cachedBlock.getDataBlockEncoding();
// Block types other than data blocks always have
// DataBlockEncoding.NONE. To avoid false negative cache misses, only
// perform this check if cached block is a data block.
if (cachedBlock.getBlockType().isData() &&
!actualDataBlockEncoding.equals(expectedDataBlockEncoding)) {
// This mismatch may happen if a Scanner, which is used for say a
// compaction, tries to read an encoded block from the block cache.
// The reverse might happen when an EncodedScanner tries to read
// un-encoded blocks which were cached earlier.
//
// Because returning a data block with an implicit BlockType mismatch
// will cause the requesting scanner to throw a disk read should be
// forced here. This will potentially cause a significant number of
// cache misses, so update so we should keep track of this as it might
// justify the work on a CompoundScanner.
if (!expectedDataBlockEncoding.equals(DataBlockEncoding.NONE) &&
!actualDataBlockEncoding.equals(DataBlockEncoding.NONE)) {
// If the block is encoded but the encoding does not match the
// expected encoding it is likely the encoding was changed but the
// block was not yet evicted. Evictions on file close happen async
// so blocks with the old encoding still linger in cache for some
// period of time. This event should be rare as it only happens on
// schema definition change.
LOG.info("Evicting cached block with key {} because data block encoding mismatch; " +
"expected {}, actual {}, path={}", cacheKey, actualDataBlockEncoding,
expectedDataBlockEncoding, path);
// This is an error scenario. so here we need to release the block.
returnAndEvictBlock(cache, cacheKey, cachedBlock);
}
return null;
}
return cachedBlock;
}
}
return null;
}
private void returnAndEvictBlock(BlockCache cache, BlockCacheKey cacheKey, Cacheable block) {
block.release();
cache.evictBlock(cacheKey);
}
/**
* @param cacheBlock Add block to cache, if found
* @return block wrapped in a ByteBuffer, with header skipped
*/
@Override
public HFileBlock getMetaBlock(String metaBlockName, boolean cacheBlock)
throws IOException {
if (trailer.getMetaIndexCount() == 0) {
return null; // there are no meta blocks
}
if (metaBlockIndexReader == null) {
throw new IOException(path + " meta index not loaded");
}
byte[] mbname = Bytes.toBytes(metaBlockName);
int block = metaBlockIndexReader.rootBlockContainingKey(mbname,
0, mbname.length);
if (block == -1) {
return null;
}
long blockSize = metaBlockIndexReader.getRootBlockDataSize(block);
// Per meta key from any given file, synchronize reads for said block. This
// is OK to do for meta blocks because the meta block index is always
// single-level.
synchronized (metaBlockIndexReader.getRootBlockKey(block)) {
// Check cache for block. If found return.
long metaBlockOffset = metaBlockIndexReader.getRootBlockOffset(block);
BlockCacheKey cacheKey =
new BlockCacheKey(name, metaBlockOffset, this.isPrimaryReplicaReader(), BlockType.META);
cacheBlock &= cacheConf.shouldCacheBlockOnRead(BlockType.META.getCategory());
HFileBlock cachedBlock =
getCachedBlock(cacheKey, cacheBlock, false, true, true, BlockType.META, null);
if (cachedBlock != null) {
assert cachedBlock.isUnpacked() : "Packed block leak.";
// Return a distinct 'shallow copy' of the block,
// so pos does not get messed by the scanner
return cachedBlock;
}
// Cache Miss, please load.
HFileBlock compressedBlock =
fsBlockReader.readBlockData(metaBlockOffset, blockSize, true, false, true);
HFileBlock uncompressedBlock = compressedBlock.unpack(hfileContext, fsBlockReader);
if (compressedBlock != uncompressedBlock) {
compressedBlock.release();
}
// Cache the block
if (cacheBlock) {
cacheConf.getBlockCache().ifPresent(
cache -> cache.cacheBlock(cacheKey, uncompressedBlock, cacheConf.isInMemory()));
}
return uncompressedBlock;
}
}
/**
* If expected block is data block, we'll allocate the ByteBuff of block from
* {@link org.apache.hadoop.hbase.io.ByteBuffAllocator} and it's usually an off-heap one,
* otherwise it will allocate from heap.
* @see org.apache.hadoop.hbase.io.hfile.HFileBlock.FSReader#readBlockData(long, long, boolean,
* boolean, boolean)
*/
private boolean shouldUseHeap(BlockType expectedBlockType) {
if (!cacheConf.getBlockCache().isPresent()) {
return false;
} else if (!cacheConf.isCombinedBlockCache()) {
// Block to cache in LruBlockCache must be an heap one. So just allocate block memory from
// heap for saving an extra off-heap to heap copying.
return true;
}
return expectedBlockType != null && !expectedBlockType.isData();
}
@Override
public HFileBlock readBlock(long dataBlockOffset, long onDiskBlockSize,
final boolean cacheBlock, boolean pread, final boolean isCompaction,
boolean updateCacheMetrics, BlockType expectedBlockType,
DataBlockEncoding expectedDataBlockEncoding)
throws IOException {
if (dataBlockIndexReader == null) {
throw new IOException(path + " block index not loaded");
}
long trailerOffset = trailer.getLoadOnOpenDataOffset();
if (dataBlockOffset < 0 || dataBlockOffset >= trailerOffset) {
throw new IOException("Requested block is out of range: " + dataBlockOffset +
", lastDataBlockOffset: " + trailer.getLastDataBlockOffset() +
", trailer.getLoadOnOpenDataOffset: " + trailerOffset +
", path=" + path);
}
// For any given block from any given file, synchronize reads for said
// block.
// Without a cache, this synchronizing is needless overhead, but really
// the other choice is to duplicate work (which the cache would prevent you
// from doing).
BlockCacheKey cacheKey = new BlockCacheKey(name, dataBlockOffset,
this.isPrimaryReplicaReader(), expectedBlockType);
boolean useLock = false;
IdLock.Entry lockEntry = null;
try (TraceScope traceScope = TraceUtil.createTrace("HFileReaderImpl.readBlock")) {
while (true) {
// Check cache for block. If found return.
if (cacheConf.shouldReadBlockFromCache(expectedBlockType)) {
if (useLock) {
lockEntry = offsetLock.getLockEntry(dataBlockOffset);
}
// Try and get the block from the block cache. If the useLock variable is true then this
// is the second time through the loop and it should not be counted as a block cache miss.
HFileBlock cachedBlock = getCachedBlock(cacheKey, cacheBlock, useLock, isCompaction,
updateCacheMetrics, expectedBlockType, expectedDataBlockEncoding);
if (cachedBlock != null) {
if (LOG.isTraceEnabled()) {
LOG.trace("From Cache " + cachedBlock);
}
TraceUtil.addTimelineAnnotation("blockCacheHit");
assert cachedBlock.isUnpacked() : "Packed block leak.";
if (cachedBlock.getBlockType().isData()) {
if (updateCacheMetrics) {
HFile.DATABLOCK_READ_COUNT.increment();
}
// Validate encoding type for data blocks. We include encoding
// type in the cache key, and we expect it to match on a cache hit.
if (cachedBlock.getDataBlockEncoding() != dataBlockEncoder.getDataBlockEncoding()) {
// Remember to release the block when in exceptional path.
cacheConf.getBlockCache().ifPresent(cache -> {
returnAndEvictBlock(cache, cacheKey, cachedBlock);
});
throw new IOException("Cached block under key " + cacheKey + " "
+ "has wrong encoding: " + cachedBlock.getDataBlockEncoding() + " (expected: "
+ dataBlockEncoder.getDataBlockEncoding() + "), path=" + path);
}
}
// Cache-hit. Return!
return cachedBlock;
}
if (!useLock && cacheBlock && cacheConf.shouldLockOnCacheMiss(expectedBlockType)) {
// check cache again with lock
useLock = true;
continue;
}
// Carry on, please load.
}
TraceUtil.addTimelineAnnotation("blockCacheMiss");
// Load block from filesystem.
HFileBlock hfileBlock = fsBlockReader.readBlockData(dataBlockOffset, onDiskBlockSize, pread,
!isCompaction, shouldUseHeap(expectedBlockType));
validateBlockType(hfileBlock, expectedBlockType);
HFileBlock unpacked = hfileBlock.unpack(hfileContext, fsBlockReader);
BlockType.BlockCategory category = hfileBlock.getBlockType().getCategory();
// Cache the block if necessary
cacheConf.getBlockCache().ifPresent(cache -> {
if (cacheBlock && cacheConf.shouldCacheBlockOnRead(category)) {
cache.cacheBlock(cacheKey,
cacheConf.shouldCacheCompressed(category) ? hfileBlock : unpacked,
cacheConf.isInMemory());
}
});
if (unpacked != hfileBlock) {
// End of life here if hfileBlock is an independent block.
hfileBlock.release();
}
if (updateCacheMetrics && hfileBlock.getBlockType().isData()) {
HFile.DATABLOCK_READ_COUNT.increment();
}
return unpacked;
}
} finally {
if (lockEntry != null) {
offsetLock.releaseLockEntry(lockEntry);
}
}
}
@Override
public boolean hasMVCCInfo() {
return fileInfo.shouldIncludeMemStoreTS() && fileInfo.isDecodeMemstoreTS();
}
/**
* Compares the actual type of a block retrieved from cache or disk with its
* expected type and throws an exception in case of a mismatch. Expected
* block type of {@link BlockType#DATA} is considered to match the actual
* block type [@link {@link BlockType#ENCODED_DATA} as well.
* @param block a block retrieved from cache or disk
* @param expectedBlockType the expected block type, or null to skip the
* check
*/
private void validateBlockType(HFileBlock block,
BlockType expectedBlockType) throws IOException {
if (expectedBlockType == null) {
return;
}
BlockType actualBlockType = block.getBlockType();
if (expectedBlockType.isData() && actualBlockType.isData()) {
// We consider DATA to match ENCODED_DATA for the purpose of this
// verification.
return;
}
if (actualBlockType != expectedBlockType) {
throw new IOException("Expected block type " + expectedBlockType + ", " +
"but got " + actualBlockType + ": " + block + ", path=" + path);
}
}
/**
* @return Last key as cell in the file. May be null if file has no entries. Note that
* this is not the last row key, but it is the Cell representation of the last
* key
*/
@Override
public Optional<Cell> getLastKey() {
return dataBlockIndexReader.isEmpty() ? Optional.empty() :
Optional.of(fileInfo.getLastKeyCell());
}
/**
* @return Midkey for this file. We work with block boundaries only so
* returned midkey is an approximation only.
*/
@Override
public Optional<Cell> midKey() throws IOException {
return Optional.ofNullable(dataBlockIndexReader.midkey(this));
}
@Override
public void close() throws IOException {
close(cacheConf.shouldEvictOnClose());
}
@Override
public DataBlockEncoding getEffectiveEncodingInCache(boolean isCompaction) {
return dataBlockEncoder.getEffectiveEncodingInCache(isCompaction);
}
/** For testing */
@Override
public HFileBlock.FSReader getUncachedBlockReader() {
return fsBlockReader;
}
/**
* Scanner that operates on encoded data blocks.
*/
protected static class EncodedScanner extends HFileScannerImpl {
private final HFileBlockDecodingContext decodingCtx;
private final DataBlockEncoder.EncodedSeeker seeker;
private final DataBlockEncoder dataBlockEncoder;
public EncodedScanner(HFile.Reader reader, boolean cacheBlocks,
boolean pread, boolean isCompaction, HFileContext meta) {
super(reader, cacheBlocks, pread, isCompaction);
DataBlockEncoding encoding = reader.getDataBlockEncoding();
dataBlockEncoder = encoding.getEncoder();
decodingCtx = dataBlockEncoder.newDataBlockDecodingContext(meta);
seeker = dataBlockEncoder.createSeeker(decodingCtx);
}
@Override
public boolean isSeeked(){
return curBlock != null;
}
@Override
public void setNonSeekedState() {
reset();
}
/**
* Updates the current block to be the given {@link HFileBlock}. Seeks to the the first
* key/value pair.
* @param newBlock the block to make current, and read by {@link HFileReaderImpl#readBlock},
* it's a totally new block with new allocated {@link ByteBuff}, so if no further
* reference to this block, we should release it carefully.
*/
@Override
protected void updateCurrentBlock(HFileBlock newBlock) throws CorruptHFileException {
try {
// sanity checks
if (newBlock.getBlockType() != BlockType.ENCODED_DATA) {
throw new IllegalStateException("EncodedScanner works only on encoded data blocks");
}
short dataBlockEncoderId = newBlock.getDataBlockEncodingId();
if (!DataBlockEncoding.isCorrectEncoder(dataBlockEncoder, dataBlockEncoderId)) {
String encoderCls = dataBlockEncoder.getClass().getName();
throw new CorruptHFileException("Encoder " + encoderCls +
" doesn't support data block encoding " +
DataBlockEncoding.getNameFromId(dataBlockEncoderId) + ",path=" + reader.getPath());
}
updateCurrBlockRef(newBlock);
ByteBuff encodedBuffer = getEncodedBuffer(newBlock);
seeker.setCurrentBuffer(encodedBuffer);
} finally {
releaseIfNotCurBlock(newBlock);
}
// Reset the next indexed key
this.nextIndexedKey = null;
}
private ByteBuff getEncodedBuffer(HFileBlock newBlock) {
ByteBuff origBlock = newBlock.getBufferReadOnly();
int pos = newBlock.headerSize() + DataBlockEncoding.ID_SIZE;
origBlock.position(pos);
origBlock
.limit(pos + newBlock.getUncompressedSizeWithoutHeader() - DataBlockEncoding.ID_SIZE);
return origBlock.slice();
}
@Override
protected boolean processFirstDataBlock() throws IOException {
seeker.rewind();
return true;
}
@Override
public boolean next() throws IOException {
boolean isValid = seeker.next();
if (!isValid) {
HFileBlock newBlock = readNextDataBlock();
isValid = newBlock != null;
if (isValid) {
updateCurrentBlock(newBlock);
} else {
setNonSeekedState();
}
}
return isValid;
}
@Override
public Cell getKey() {
assertValidSeek();
return seeker.getKey();
}
@Override
public ByteBuffer getValue() {
assertValidSeek();
return seeker.getValueShallowCopy();
}
@Override
public Cell getCell() {
if (this.curBlock == null) {
return null;
}
return seeker.getCell();
}
@Override
public String getKeyString() {
return CellUtil.toString(getKey(), true);
}
@Override
public String getValueString() {
ByteBuffer valueBuffer = getValue();
return ByteBufferUtils.toStringBinary(valueBuffer);
}
private void assertValidSeek() {
if (this.curBlock == null) {
throw new NotSeekedException(reader.getPath());
}
}
@Override
protected Cell getFirstKeyCellInBlock(HFileBlock curBlock) {
return dataBlockEncoder.getFirstKeyCellInBlock(getEncodedBuffer(curBlock));
}
@Override
protected int loadBlockAndSeekToKey(HFileBlock seekToBlock, Cell nextIndexedKey,
boolean rewind, Cell key, boolean seekBefore) throws IOException {
if (this.curBlock == null || this.curBlock.getOffset() != seekToBlock.getOffset()) {
updateCurrentBlock(seekToBlock);
} else if (rewind) {
seeker.rewind();
}
this.nextIndexedKey = nextIndexedKey;
return seeker.seekToKeyInBlock(key, seekBefore);
}
@Override
public int compareKey(CellComparator comparator, Cell key) {
return seeker.compareKey(comparator, key);
}
}
/**
* Returns a buffer with the Bloom filter metadata. The caller takes
* ownership of the buffer.
*/
@Override
public DataInput getGeneralBloomFilterMetadata() throws IOException {
return this.getBloomFilterMetadata(BlockType.GENERAL_BLOOM_META);
}
@Override
public DataInput getDeleteBloomFilterMetadata() throws IOException {
return this.getBloomFilterMetadata(BlockType.DELETE_FAMILY_BLOOM_META);
}
private DataInput getBloomFilterMetadata(BlockType blockType)
throws IOException {
if (blockType != BlockType.GENERAL_BLOOM_META &&
blockType != BlockType.DELETE_FAMILY_BLOOM_META) {
throw new RuntimeException("Block Type: " + blockType.toString() +
" is not supported, path=" + path) ;
}
for (HFileBlock b : fileInfo.getLoadOnOpenBlocks()) {
if (b.getBlockType() == blockType) {
return b.getByteStream();
}
}
return null;
}
public boolean isFileInfoLoaded() {
return true; // We load file info in constructor in version 2.
}
@Override
public HFileContext getFileContext() {
return hfileContext;
}
/**
* Returns false if block prefetching was requested for this file and has
* not completed, true otherwise
*/
@Override
@VisibleForTesting
public boolean prefetchComplete() {
return PrefetchExecutor.isCompleted(path);
}
/**
* Create a Scanner on this file. No seeks or reads are done on creation. Call
* {@link HFileScanner#seekTo(Cell)} to position an start the read. There is
* nothing to clean up in a Scanner. Letting go of your references to the
* scanner is sufficient. NOTE: Do not use this overload of getScanner for
* compactions. See {@link #getScanner(boolean, boolean, boolean)}
*
* @param cacheBlocks True if we should cache blocks read in by this scanner.
* @param pread Use positional read rather than seek+read if true (pread is
* better for random reads, seek+read is better scanning).
* @return Scanner on this file.
*/
@Override
@VisibleForTesting
public HFileScanner getScanner(boolean cacheBlocks, final boolean pread) {
return getScanner(cacheBlocks, pread, false);
}
/**
* Create a Scanner on this file. No seeks or reads are done on creation. Call
* {@link HFileScanner#seekTo(Cell)} to position an start the read. There is
* nothing to clean up in a Scanner. Letting go of your references to the
* scanner is sufficient.
* @param cacheBlocks
* True if we should cache blocks read in by this scanner.
* @param pread
* Use positional read rather than seek+read if true (pread is better
* for random reads, seek+read is better scanning).
* @param isCompaction
* is scanner being used for a compaction?
* @return Scanner on this file.
*/
@Override
public HFileScanner getScanner(boolean cacheBlocks, final boolean pread,
final boolean isCompaction) {
if (dataBlockEncoder.useEncodedScanner()) {
return new EncodedScanner(this, cacheBlocks, pread, isCompaction, this.hfileContext);
}
return new HFileScannerImpl(this, cacheBlocks, pread, isCompaction);
}
public int getMajorVersion() {
return 3;
}
@Override
public void unbufferStream() {
fsBlockReader.unbufferStream();
}
}