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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 static org.apache.hadoop.hbase.io.ByteBuffAllocator.HEAP;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.fs.HFileSystem;
import org.apache.hadoop.hbase.io.ByteArrayOutputStream;
import org.apache.hadoop.hbase.io.ByteBuffAllocator;
import org.apache.hadoop.hbase.io.ByteBuffInputStream;
import org.apache.hadoop.hbase.io.ByteBufferWriterDataOutputStream;
import org.apache.hadoop.hbase.io.FSDataInputStreamWrapper;
import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
import org.apache.hadoop.hbase.io.encoding.EncodingState;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDecodingContext;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultDecodingContext;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultEncodingContext;
import org.apache.hadoop.hbase.io.encoding.HFileBlockEncodingContext;
import org.apache.hadoop.hbase.io.util.BlockIOUtils;
import org.apache.hadoop.hbase.nio.ByteBuff;
import org.apache.hadoop.hbase.nio.MultiByteBuff;
import org.apache.hadoop.hbase.nio.SingleByteBuff;
import org.apache.hadoop.hbase.regionserver.ShipperListener;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.ChecksumType;
import org.apache.hadoop.hbase.util.ClassSize;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
/**
* Cacheable Blocks of an {@link HFile} version 2 file.
* Version 2 was introduced in hbase-0.92.0.
*
* Version 1 was the original file block. Version 2 was introduced when we changed the hbase file
* format to support multi-level block indexes and compound bloom filters (HBASE-3857). Support
* for Version 1 was removed in hbase-1.3.0.
*
*
HFileBlock: Version 2
* In version 2, a block is structured as follows:
*
* - Header: See Writer#putHeader() for where header is written; header total size is
* HFILEBLOCK_HEADER_SIZE
*
* - 0. blockType: Magic record identifying the {@link BlockType} (8 bytes):
* e.g.
DATABLK*
* - 1. onDiskSizeWithoutHeader: Compressed -- a.k.a 'on disk' -- block size, excluding header,
* but including tailing checksum bytes (4 bytes)
*
- 2. uncompressedSizeWithoutHeader: Uncompressed block size, excluding header, and excluding
* checksum bytes (4 bytes)
*
- 3. prevBlockOffset: The offset of the previous block of the same type (8 bytes). This is
* used to navigate to the previous block without having to go to the block index
*
- 4: For minorVersions >=1, the ordinal describing checksum type (1 byte)
*
- 5: For minorVersions >=1, the number of data bytes/checksum chunk (4 bytes)
*
- 6: onDiskDataSizeWithHeader: For minorVersions >=1, the size of data 'on disk', including
* header, excluding checksums (4 bytes)
*
*
* - Raw/Compressed/Encrypted/Encoded data: The compression
* algorithm is the same for all the blocks in an {@link HFile}. If compression is NONE, this is
* just raw, serialized Cells.
*
- Tail: For minorVersions >=1, a series of 4 byte checksums, one each for
* the number of bytes specified by bytesPerChecksum.
*
*
* Caching
* Caches cache whole blocks with trailing checksums if any. We then tag on some metadata, the
* content of BLOCK_METADATA_SPACE which will be flag on if we are doing 'hbase'
* checksums and then the offset into the file which is needed when we re-make a cache key
* when we return the block to the cache as 'done'.
* See {@link Cacheable#serialize(ByteBuffer, boolean)} and {@link Cacheable#getDeserializer()}.
*
* TODO: Should we cache the checksums? Down in Writer#getBlockForCaching(CacheConfig) where
* we make a block to cache-on-write, there is an attempt at turning off checksums. This is not the
* only place we get blocks to cache. We also will cache the raw return from an hdfs read. In this
* case, the checksums may be present. If the cache is backed by something that doesn't do ECC,
* say an SSD, we might want to preserve checksums. For now this is open question.
*
TODO: Over in BucketCache, we save a block allocation by doing a custom serialization.
* Be sure to change it if serialization changes in here. Could we add a method here that takes an
* IOEngine and that then serializes to it rather than expose our internals over in BucketCache?
* IOEngine is in the bucket subpackage. Pull it up? Then this class knows about bucketcache. Ugh.
*/
@InterfaceAudience.Private
public class HFileBlock implements Cacheable {
private static final Logger LOG = LoggerFactory.getLogger(HFileBlock.class);
public static final long FIXED_OVERHEAD = ClassSize.estimateBase(HFileBlock.class, false);
// Block Header fields.
// TODO: encapsulate Header related logic in this inner class.
static class Header {
// Format of header is:
// 8 bytes - block magic
// 4 bytes int - onDiskSizeWithoutHeader
// 4 bytes int - uncompressedSizeWithoutHeader
// 8 bytes long - prevBlockOffset
// The following 3 are only present if header contains checksum information
// 1 byte - checksum type
// 4 byte int - bytes per checksum
// 4 byte int - onDiskDataSizeWithHeader
static int BLOCK_MAGIC_INDEX = 0;
static int ON_DISK_SIZE_WITHOUT_HEADER_INDEX = 8;
static int UNCOMPRESSED_SIZE_WITHOUT_HEADER_INDEX = 12;
static int PREV_BLOCK_OFFSET_INDEX = 16;
static int CHECKSUM_TYPE_INDEX = 24;
static int BYTES_PER_CHECKSUM_INDEX = 25;
static int ON_DISK_DATA_SIZE_WITH_HEADER_INDEX = 29;
}
/** Type of block. Header field 0. */
private BlockType blockType;
/**
* Size on disk excluding header, including checksum. Header field 1.
* @see Writer#putHeader(byte[], int, int, int, int)
*/
private int onDiskSizeWithoutHeader;
/**
* Size of pure data. Does not include header or checksums. Header field 2.
* @see Writer#putHeader(byte[], int, int, int, int)
*/
private int uncompressedSizeWithoutHeader;
/**
* The offset of the previous block on disk. Header field 3.
* @see Writer#putHeader(byte[], int, int, int, int)
*/
private long prevBlockOffset;
/**
* Size on disk of header + data. Excludes checksum. Header field 6,
* OR calculated from {@link #onDiskSizeWithoutHeader} when using HDFS checksum.
* @see Writer#putHeader(byte[], int, int, int, int)
*/
private int onDiskDataSizeWithHeader;
// End of Block Header fields.
/**
* The in-memory representation of the hfile block. Can be on or offheap. Can be backed by
* a single ByteBuffer or by many. Make no assumptions.
*
*
Be careful reading from this buf. Duplicate and work on the duplicate or if
* not, be sure to reset position and limit else trouble down the road.
*
*
TODO: Make this read-only once made.
*
*
We are using the ByteBuff type. ByteBuffer is not extensible yet we need to be able to have
* a ByteBuffer-like API across multiple ByteBuffers reading from a cache such as BucketCache.
* So, we have this ByteBuff type. Unfortunately, it is spread all about HFileBlock. Would be
* good if could be confined to cache-use only but hard-to-do.
*/
private ByteBuff buf;
/** Meta data that holds meta information on the hfileblock.
*/
private HFileContext fileContext;
/**
* The offset of this block in the file. Populated by the reader for
* convenience of access. This offset is not part of the block header.
*/
private long offset = UNSET;
/**
* The on-disk size of the next block, including the header and checksums if present.
* UNSET if unknown.
*
* Blocks try to carry the size of the next block to read in this data member. Usually
* we get block sizes from the hfile index but sometimes the index is not available:
* e.g. when we read the indexes themselves (indexes are stored in blocks, we do not
* have an index for the indexes). Saves seeks especially around file open when
* there is a flurry of reading in hfile metadata.
*/
private int nextBlockOnDiskSize = UNSET;
private ByteBuffAllocator allocator;
/**
* On a checksum failure, do these many succeeding read requests using hdfs checksums before
* auto-reenabling hbase checksum verification.
*/
static final int CHECKSUM_VERIFICATION_NUM_IO_THRESHOLD = 3;
private static int UNSET = -1;
public static final boolean FILL_HEADER = true;
public static final boolean DONT_FILL_HEADER = false;
// How to get the estimate correctly? if it is a singleBB?
public static final int MULTI_BYTE_BUFFER_HEAP_SIZE =
(int)ClassSize.estimateBase(MultiByteBuff.class, false);
/**
* Space for metadata on a block that gets stored along with the block when we cache it.
* There are a few bytes stuck on the end of the HFileBlock that we pull in from HDFS.
* 8 bytes are for the offset of this block (long) in the file. Offset is important because is is
* used when we remake the CacheKey when we return block to the cache when done. There is also
* a flag on whether checksumming is being done by hbase or not. See class comment for note on
* uncertain state of checksumming of blocks that come out of cache (should we or should we not?).
* Finally there are 4 bytes to hold the length of the next block which can save a seek on
* occasion if available.
* (This EXTRA info came in with original commit of the bucketcache, HBASE-7404. It was
* formerly known as EXTRA_SERIALIZATION_SPACE).
*/
static final int BLOCK_METADATA_SPACE = Bytes.SIZEOF_BYTE + Bytes.SIZEOF_LONG + Bytes.SIZEOF_INT;
/**
* Each checksum value is an integer that can be stored in 4 bytes.
*/
static final int CHECKSUM_SIZE = Bytes.SIZEOF_INT;
static final byte[] DUMMY_HEADER_NO_CHECKSUM =
new byte[HConstants.HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM];
/**
* Used deserializing blocks from Cache.
*
*
* ++++++++++++++
* + HFileBlock +
* ++++++++++++++
* + Checksums + <= Optional
* ++++++++++++++
* + Metadata! + <= See note on BLOCK_METADATA_SPACE above.
* ++++++++++++++
*
* @see #serialize(ByteBuffer, boolean)
*/
public static final CacheableDeserializer BLOCK_DESERIALIZER = new BlockDeserializer();
public static final class BlockDeserializer implements CacheableDeserializer {
private BlockDeserializer() {
}
@Override
public HFileBlock deserialize(ByteBuff buf, ByteBuffAllocator alloc)
throws IOException {
// The buf has the file block followed by block metadata.
// Set limit to just before the BLOCK_METADATA_SPACE then rewind.
buf.limit(buf.limit() - BLOCK_METADATA_SPACE).rewind();
// Get a new buffer to pass the HFileBlock for it to 'own'.
ByteBuff newByteBuff = buf.slice();
// Read out the BLOCK_METADATA_SPACE content and shove into our HFileBlock.
buf.position(buf.limit());
buf.limit(buf.limit() + HFileBlock.BLOCK_METADATA_SPACE);
boolean usesChecksum = buf.get() == (byte) 1;
long offset = buf.getLong();
int nextBlockOnDiskSize = buf.getInt();
return createFromBuff(newByteBuff, usesChecksum, offset, nextBlockOnDiskSize, null, alloc);
}
@Override
public int getDeserializerIdentifier() {
return DESERIALIZER_IDENTIFIER;
}
}
private static final int DESERIALIZER_IDENTIFIER;
static {
DESERIALIZER_IDENTIFIER =
CacheableDeserializerIdManager.registerDeserializer(BLOCK_DESERIALIZER);
}
/**
* Creates a new {@link HFile} block from the given fields. This constructor
* is used only while writing blocks and caching,
* and is sitting in a byte buffer and we want to stuff the block into cache.
* See {@link Writer#getBlockForCaching(CacheConfig)}.
*
* TODO: The caller presumes no checksumming
*
TODO: HFile block writer can also off-heap ?
* required of this block instance since going into cache; checksum already verified on
* underlying block data pulled in from filesystem. Is that correct? What if cache is SSD?
*
* @param blockType the type of this block, see {@link BlockType}
* @param onDiskSizeWithoutHeader see {@link #onDiskSizeWithoutHeader}
* @param uncompressedSizeWithoutHeader see {@link #uncompressedSizeWithoutHeader}
* @param prevBlockOffset see {@link #prevBlockOffset}
* @param buf block buffer with header ({@link HConstants#HFILEBLOCK_HEADER_SIZE} bytes)
* @param fillHeader when true, write the first 4 header fields into passed buffer.
* @param offset the file offset the block was read from
* @param onDiskDataSizeWithHeader see {@link #onDiskDataSizeWithHeader}
* @param fileContext HFile meta data
*/
public HFileBlock(BlockType blockType, int onDiskSizeWithoutHeader,
int uncompressedSizeWithoutHeader, long prevBlockOffset, ByteBuff buf, boolean fillHeader,
long offset, int nextBlockOnDiskSize, int onDiskDataSizeWithHeader, HFileContext fileContext,
ByteBuffAllocator allocator) {
this.blockType = blockType;
this.onDiskSizeWithoutHeader = onDiskSizeWithoutHeader;
this.uncompressedSizeWithoutHeader = uncompressedSizeWithoutHeader;
this.prevBlockOffset = prevBlockOffset;
this.offset = offset;
this.onDiskDataSizeWithHeader = onDiskDataSizeWithHeader;
this.nextBlockOnDiskSize = nextBlockOnDiskSize;
this.fileContext = fileContext;
this.allocator = allocator;
this.buf = buf;
if (fillHeader) {
overwriteHeader();
}
this.buf.rewind();
}
/**
* Creates a block from an existing buffer starting with a header. Rewinds
* and takes ownership of the buffer. By definition of rewind, ignores the
* buffer position, but if you slice the buffer beforehand, it will rewind
* to that point.
* @param buf Has header, content, and trailing checksums if present.
*/
static HFileBlock createFromBuff(ByteBuff buf, boolean usesHBaseChecksum, final long offset,
final int nextBlockOnDiskSize, HFileContext fileContext, ByteBuffAllocator allocator)
throws IOException {
buf.rewind();
final BlockType blockType = BlockType.read(buf);
final int onDiskSizeWithoutHeader = buf.getInt(Header.ON_DISK_SIZE_WITHOUT_HEADER_INDEX);
final int uncompressedSizeWithoutHeader =
buf.getInt(Header.UNCOMPRESSED_SIZE_WITHOUT_HEADER_INDEX);
final long prevBlockOffset = buf.getLong(Header.PREV_BLOCK_OFFSET_INDEX);
// This constructor is called when we deserialize a block from cache and when we read a block in
// from the fs. fileCache is null when deserialized from cache so need to make up one.
HFileContextBuilder fileContextBuilder = fileContext != null ?
new HFileContextBuilder(fileContext) : new HFileContextBuilder();
fileContextBuilder.withHBaseCheckSum(usesHBaseChecksum);
int onDiskDataSizeWithHeader;
if (usesHBaseChecksum) {
byte checksumType = buf.get(Header.CHECKSUM_TYPE_INDEX);
int bytesPerChecksum = buf.getInt(Header.BYTES_PER_CHECKSUM_INDEX);
onDiskDataSizeWithHeader = buf.getInt(Header.ON_DISK_DATA_SIZE_WITH_HEADER_INDEX);
// Use the checksum type and bytes per checksum from header, not from fileContext.
fileContextBuilder.withChecksumType(ChecksumType.codeToType(checksumType));
fileContextBuilder.withBytesPerCheckSum(bytesPerChecksum);
} else {
fileContextBuilder.withChecksumType(ChecksumType.NULL);
fileContextBuilder.withBytesPerCheckSum(0);
// Need to fix onDiskDataSizeWithHeader; there are not checksums after-block-data
onDiskDataSizeWithHeader = onDiskSizeWithoutHeader + headerSize(usesHBaseChecksum);
}
fileContext = fileContextBuilder.build();
assert usesHBaseChecksum == fileContext.isUseHBaseChecksum();
return new HFileBlockBuilder()
.withBlockType(blockType)
.withOnDiskSizeWithoutHeader(onDiskSizeWithoutHeader)
.withUncompressedSizeWithoutHeader(uncompressedSizeWithoutHeader)
.withPrevBlockOffset(prevBlockOffset)
.withOffset(offset)
.withOnDiskDataSizeWithHeader(onDiskDataSizeWithHeader)
.withNextBlockOnDiskSize(nextBlockOnDiskSize)
.withHFileContext(fileContext)
.withByteBuffAllocator(allocator)
.withByteBuff(buf.rewind())
.withShared(!buf.hasArray())
.build();
}
/**
* Parse total on disk size including header and checksum.
* @param headerBuf Header ByteBuffer. Presumed exact size of header.
* @param verifyChecksum true if checksum verification is in use.
* @return Size of the block with header included.
*/
private static int getOnDiskSizeWithHeader(final ByteBuff headerBuf,
boolean verifyChecksum) {
return headerBuf.getInt(Header.ON_DISK_SIZE_WITHOUT_HEADER_INDEX) + headerSize(verifyChecksum);
}
/**
* @return the on-disk size of the next block (including the header size and any checksums if
* present) read by peeking into the next block's header; use as a hint when doing
* a read of the next block when scanning or running over a file.
*/
int getNextBlockOnDiskSize() {
return nextBlockOnDiskSize;
}
@Override
public BlockType getBlockType() {
return blockType;
}
@Override
public int refCnt() {
return buf.refCnt();
}
@Override
public HFileBlock retain() {
buf.retain();
return this;
}
/**
* Call {@link ByteBuff#release()} to decrease the reference count, if no other reference, it will
* return back the {@link ByteBuffer} to {@link org.apache.hadoop.hbase.io.ByteBuffAllocator}
*/
@Override
public boolean release() {
return buf.release();
}
/** @return get data block encoding id that was used to encode this block */
short getDataBlockEncodingId() {
if (blockType != BlockType.ENCODED_DATA) {
throw new IllegalArgumentException("Querying encoder ID of a block " +
"of type other than " + BlockType.ENCODED_DATA + ": " + blockType);
}
return buf.getShort(headerSize());
}
/**
* @return the on-disk size of header + data part + checksum.
*/
public int getOnDiskSizeWithHeader() {
return onDiskSizeWithoutHeader + headerSize();
}
/**
* @return the on-disk size of the data part + checksum (header excluded).
*/
int getOnDiskSizeWithoutHeader() {
return onDiskSizeWithoutHeader;
}
/**
* @return the uncompressed size of data part (header and checksum excluded).
*/
int getUncompressedSizeWithoutHeader() {
return uncompressedSizeWithoutHeader;
}
/**
* @return the offset of the previous block of the same type in the file, or
* -1 if unknown
*/
long getPrevBlockOffset() {
return prevBlockOffset;
}
/**
* Rewinds {@code buf} and writes first 4 header fields. {@code buf} position
* is modified as side-effect.
*/
private void overwriteHeader() {
buf.rewind();
blockType.write(buf);
buf.putInt(onDiskSizeWithoutHeader);
buf.putInt(uncompressedSizeWithoutHeader);
buf.putLong(prevBlockOffset);
if (this.fileContext.isUseHBaseChecksum()) {
buf.put(fileContext.getChecksumType().getCode());
buf.putInt(fileContext.getBytesPerChecksum());
buf.putInt(onDiskDataSizeWithHeader);
}
}
/**
* Returns a buffer that does not include the header and checksum.
* @return the buffer with header skipped and checksum omitted.
*/
public ByteBuff getBufferWithoutHeader() {
return this.getBufferWithoutHeader(false);
}
/**
* Returns a buffer that does not include the header or checksum.
* @param withChecksum to indicate whether include the checksum or not.
* @return the buffer with header skipped and checksum omitted.
*/
public ByteBuff getBufferWithoutHeader(boolean withChecksum) {
ByteBuff dup = getBufferReadOnly();
int delta = withChecksum ? 0 : totalChecksumBytes();
return dup.position(headerSize()).limit(buf.limit() - delta).slice();
}
/**
* Returns a read-only duplicate of the buffer this block stores internally ready to be read.
* Clients must not modify the buffer object though they may set position and limit on the
* returned buffer since we pass back a duplicate. This method has to be public because it is used
* in {@link CompoundBloomFilter} to avoid object creation on every Bloom
* filter lookup, but has to be used with caution. Buffer holds header, block content,
* and any follow-on checksums if present.
*
* @return the buffer of this block for read-only operations
*/
public ByteBuff getBufferReadOnly() {
// TODO: ByteBuf does not support asReadOnlyBuffer(). Fix.
ByteBuff dup = this.buf.duplicate();
assert dup.position() == 0;
return dup;
}
public ByteBuffAllocator getByteBuffAllocator() {
return this.allocator;
}
private void sanityCheckAssertion(long valueFromBuf, long valueFromField,
String fieldName) throws IOException {
if (valueFromBuf != valueFromField) {
throw new AssertionError(fieldName + " in the buffer (" + valueFromBuf
+ ") is different from that in the field (" + valueFromField + ")");
}
}
private void sanityCheckAssertion(BlockType valueFromBuf, BlockType valueFromField)
throws IOException {
if (valueFromBuf != valueFromField) {
throw new IOException("Block type stored in the buffer: " +
valueFromBuf + ", block type field: " + valueFromField);
}
}
/**
* Checks if the block is internally consistent, i.e. the first
* {@link HConstants#HFILEBLOCK_HEADER_SIZE} bytes of the buffer contain a
* valid header consistent with the fields. Assumes a packed block structure.
* This function is primary for testing and debugging, and is not
* thread-safe, because it alters the internal buffer pointer.
* Used by tests only.
*/
void sanityCheck() throws IOException {
// Duplicate so no side-effects
ByteBuff dup = this.buf.duplicate().rewind();
sanityCheckAssertion(BlockType.read(dup), blockType);
sanityCheckAssertion(dup.getInt(), onDiskSizeWithoutHeader, "onDiskSizeWithoutHeader");
sanityCheckAssertion(dup.getInt(), uncompressedSizeWithoutHeader,
"uncompressedSizeWithoutHeader");
sanityCheckAssertion(dup.getLong(), prevBlockOffset, "prevBlockOffset");
if (this.fileContext.isUseHBaseChecksum()) {
sanityCheckAssertion(dup.get(), this.fileContext.getChecksumType().getCode(), "checksumType");
sanityCheckAssertion(dup.getInt(), this.fileContext.getBytesPerChecksum(),
"bytesPerChecksum");
sanityCheckAssertion(dup.getInt(), onDiskDataSizeWithHeader, "onDiskDataSizeWithHeader");
}
int cksumBytes = totalChecksumBytes();
int expectedBufLimit = onDiskDataSizeWithHeader + cksumBytes;
if (dup.limit() != expectedBufLimit) {
throw new AssertionError("Expected limit " + expectedBufLimit + ", got " + dup.limit());
}
// We might optionally allocate HFILEBLOCK_HEADER_SIZE more bytes to read the next
// block's header, so there are two sensible values for buffer capacity.
int hdrSize = headerSize();
dup.rewind();
if (dup.remaining() != expectedBufLimit && dup.remaining() != expectedBufLimit + hdrSize) {
throw new AssertionError("Invalid buffer capacity: " + dup.remaining() +
", expected " + expectedBufLimit + " or " + (expectedBufLimit + hdrSize));
}
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder()
.append("[")
.append("blockType=").append(blockType)
.append(", fileOffset=").append(offset)
.append(", headerSize=").append(headerSize())
.append(", onDiskSizeWithoutHeader=").append(onDiskSizeWithoutHeader)
.append(", uncompressedSizeWithoutHeader=").append(uncompressedSizeWithoutHeader)
.append(", prevBlockOffset=").append(prevBlockOffset)
.append(", isUseHBaseChecksum=").append(fileContext.isUseHBaseChecksum());
if (fileContext.isUseHBaseChecksum()) {
sb.append(", checksumType=").append(ChecksumType.codeToType(this.buf.get(24)))
.append(", bytesPerChecksum=").append(this.buf.getInt(24 + 1))
.append(", onDiskDataSizeWithHeader=").append(onDiskDataSizeWithHeader);
} else {
sb.append(", onDiskDataSizeWithHeader=").append(onDiskDataSizeWithHeader)
.append("(").append(onDiskSizeWithoutHeader)
.append("+").append(HConstants.HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM).append(")");
}
String dataBegin;
if (buf.hasArray()) {
dataBegin = Bytes.toStringBinary(buf.array(), buf.arrayOffset() + headerSize(),
Math.min(32, buf.limit() - buf.arrayOffset() - headerSize()));
} else {
ByteBuff bufWithoutHeader = getBufferWithoutHeader();
byte[] dataBeginBytes = new byte[Math.min(32,
bufWithoutHeader.limit() - bufWithoutHeader.position())];
bufWithoutHeader.get(dataBeginBytes);
dataBegin = Bytes.toStringBinary(dataBeginBytes);
}
sb.append(", getOnDiskSizeWithHeader=").append(getOnDiskSizeWithHeader())
.append(", totalChecksumBytes=").append(totalChecksumBytes())
.append(", isUnpacked=").append(isUnpacked())
.append(", buf=[").append(buf).append("]")
.append(", dataBeginsWith=").append(dataBegin)
.append(", fileContext=").append(fileContext)
.append(", nextBlockOnDiskSize=").append(nextBlockOnDiskSize)
.append("]");
return sb.toString();
}
/**
* Retrieves the decompressed/decrypted view of this block. An encoded block remains in its
* encoded structure. Internal structures are shared between instances where applicable.
*/
HFileBlock unpack(HFileContext fileContext, FSReader reader) throws IOException {
if (!fileContext.isCompressedOrEncrypted()) {
// TODO: cannot use our own fileContext here because HFileBlock(ByteBuffer, boolean),
// which is used for block serialization to L2 cache, does not preserve encoding and
// encryption details.
return this;
}
HFileBlock unpacked = shallowClone(this);
unpacked.allocateBuffer(); // allocates space for the decompressed block
boolean succ = false;
try {
HFileBlockDecodingContext ctx = blockType == BlockType.ENCODED_DATA
? reader.getBlockDecodingContext() : reader.getDefaultBlockDecodingContext();
// Create a duplicated buffer without the header part.
ByteBuff dup = this.buf.duplicate();
dup.position(this.headerSize());
dup = dup.slice();
// Decode the dup into unpacked#buf
ctx.prepareDecoding(unpacked.getOnDiskSizeWithoutHeader(),
unpacked.getUncompressedSizeWithoutHeader(), unpacked.getBufferWithoutHeader(true), dup);
succ = true;
return unpacked;
} finally {
if (!succ) {
unpacked.release();
}
}
}
/**
* Always allocates a new buffer of the correct size. Copies header bytes
* from the existing buffer. Does not change header fields.
* Reserve room to keep checksum bytes too.
*/
private void allocateBuffer() {
int cksumBytes = totalChecksumBytes();
int headerSize = headerSize();
int capacityNeeded = headerSize + uncompressedSizeWithoutHeader + cksumBytes;
ByteBuff newBuf = allocator.allocate(capacityNeeded);
// Copy header bytes into newBuf.
buf.position(0);
newBuf.put(0, buf, 0, headerSize);
buf = newBuf;
// set limit to exclude next block's header
buf.limit(capacityNeeded);
}
/**
* Return true when this block's buffer has been unpacked, false otherwise. Note this is a
* calculated heuristic, not tracked attribute of the block.
*/
public boolean isUnpacked() {
final int cksumBytes = totalChecksumBytes();
final int headerSize = headerSize();
final int expectedCapacity = headerSize + uncompressedSizeWithoutHeader + cksumBytes;
final int bufCapacity = buf.remaining();
return bufCapacity == expectedCapacity || bufCapacity == expectedCapacity + headerSize;
}
/**
* Cannot be {@link #UNSET}. Must be a legitimate value. Used re-making the {@link BlockCacheKey}
* when block is returned to the cache.
* @return the offset of this block in the file it was read from
*/
long getOffset() {
if (offset < 0) {
throw new IllegalStateException("HFile block offset not initialized properly");
}
return offset;
}
/**
* @return a byte stream reading the data + checksum of this block
*/
DataInputStream getByteStream() {
ByteBuff dup = this.buf.duplicate();
dup.position(this.headerSize());
return new DataInputStream(new ByteBuffInputStream(dup));
}
@Override
public long heapSize() {
long size = FIXED_OVERHEAD;
size += fileContext.heapSize();
if (buf != null) {
// Deep overhead of the byte buffer. Needs to be aligned separately.
size += ClassSize.align(buf.capacity() + MULTI_BYTE_BUFFER_HEAP_SIZE);
}
return ClassSize.align(size);
}
/**
* Will be override by {@link SharedMemHFileBlock} or {@link ExclusiveMemHFileBlock}. Return true
* by default.
*/
public boolean isSharedMem() {
if (this instanceof SharedMemHFileBlock) {
return true;
} else if (this instanceof ExclusiveMemHFileBlock) {
return false;
}
return true;
}
/**
* Unified version 2 {@link HFile} block writer. The intended usage pattern
* is as follows:
*
* - Construct an {@link HFileBlock.Writer}, providing a compression algorithm.
*
- Call {@link Writer#startWriting} and get a data stream to write to.
*
- Write your data into the stream.
*
- Call Writer#writeHeaderAndData(FSDataOutputStream) as many times as you need to.
* store the serialized block into an external stream.
*
- Repeat to write more blocks.
*
*
*/
static class Writer implements ShipperListener {
private enum State {
INIT,
WRITING,
BLOCK_READY
};
/** Writer state. Used to ensure the correct usage protocol. */
private State state = State.INIT;
/** Data block encoder used for data blocks */
private final HFileDataBlockEncoder dataBlockEncoder;
private HFileBlockEncodingContext dataBlockEncodingCtx;
/** block encoding context for non-data blocks*/
private HFileBlockDefaultEncodingContext defaultBlockEncodingCtx;
/**
* The stream we use to accumulate data into a block in an uncompressed format.
* We reset this stream at the end of each block and reuse it. The
* header is written as the first {@link HConstants#HFILEBLOCK_HEADER_SIZE} bytes into this
* stream.
*/
private ByteArrayOutputStream baosInMemory;
/**
* Current block type. Set in {@link #startWriting(BlockType)}. Could be
* changed in {@link #finishBlock()} from {@link BlockType#DATA}
* to {@link BlockType#ENCODED_DATA}.
*/
private BlockType blockType;
/**
* A stream that we write uncompressed bytes to, which compresses them and
* writes them to {@link #baosInMemory}.
*/
private DataOutputStream userDataStream;
/**
* Bytes to be written to the file system, including the header. Compressed
* if compression is turned on. It also includes the checksum data that
* immediately follows the block data. (header + data + checksums)
*/
private ByteArrayOutputStream onDiskBlockBytesWithHeader;
/**
* The size of the checksum data on disk. It is used only if data is
* not compressed. If data is compressed, then the checksums are already
* part of onDiskBytesWithHeader. If data is uncompressed, then this
* variable stores the checksum data for this block.
*/
private byte[] onDiskChecksum = HConstants.EMPTY_BYTE_ARRAY;
/**
* Current block's start offset in the {@link HFile}. Set in
* {@link #writeHeaderAndData(FSDataOutputStream)}.
*/
private long startOffset;
/**
* Offset of previous block by block type. Updated when the next block is
* started.
*/
private long[] prevOffsetByType;
/** The offset of the previous block of the same type */
private long prevOffset;
/** Meta data that holds information about the hfileblock**/
private HFileContext fileContext;
private final ByteBuffAllocator allocator;
@Override
public void beforeShipped() {
if (getEncodingState() != null) {
getEncodingState().beforeShipped();
}
}
EncodingState getEncodingState() {
return dataBlockEncodingCtx.getEncodingState();
}
/**
* @param dataBlockEncoder data block encoding algorithm to use
*/
public Writer(HFileDataBlockEncoder dataBlockEncoder, HFileContext fileContext) {
this(dataBlockEncoder, fileContext, ByteBuffAllocator.HEAP);
}
public Writer(HFileDataBlockEncoder dataBlockEncoder, HFileContext fileContext,
ByteBuffAllocator allocator) {
if (fileContext.getBytesPerChecksum() < HConstants.HFILEBLOCK_HEADER_SIZE) {
throw new RuntimeException("Unsupported value of bytesPerChecksum. " +
" Minimum is " + HConstants.HFILEBLOCK_HEADER_SIZE + " but the configured value is " +
fileContext.getBytesPerChecksum());
}
this.allocator = allocator;
this.dataBlockEncoder = dataBlockEncoder != null?
dataBlockEncoder: NoOpDataBlockEncoder.INSTANCE;
this.dataBlockEncodingCtx = this.dataBlockEncoder.
newDataBlockEncodingContext(HConstants.HFILEBLOCK_DUMMY_HEADER, fileContext);
// TODO: This should be lazily instantiated since we usually do NOT need this default encoder
this.defaultBlockEncodingCtx = new HFileBlockDefaultEncodingContext(null,
HConstants.HFILEBLOCK_DUMMY_HEADER, fileContext);
// TODO: Set BAOS initial size. Use fileContext.getBlocksize() and add for header/checksum
baosInMemory = new ByteArrayOutputStream();
prevOffsetByType = new long[BlockType.values().length];
for (int i = 0; i < prevOffsetByType.length; ++i) {
prevOffsetByType[i] = UNSET;
}
// TODO: Why fileContext saved away when we have dataBlockEncoder and/or
// defaultDataBlockEncoder?
this.fileContext = fileContext;
}
/**
* Starts writing into the block. The previous block's data is discarded.
*
* @return the stream the user can write their data into
*/
DataOutputStream startWriting(BlockType newBlockType)
throws IOException {
if (state == State.BLOCK_READY && startOffset != -1) {
// We had a previous block that was written to a stream at a specific
// offset. Save that offset as the last offset of a block of that type.
prevOffsetByType[blockType.getId()] = startOffset;
}
startOffset = -1;
blockType = newBlockType;
baosInMemory.reset();
baosInMemory.write(HConstants.HFILEBLOCK_DUMMY_HEADER);
state = State.WRITING;
// We will compress it later in finishBlock()
userDataStream = new ByteBufferWriterDataOutputStream(baosInMemory);
if (newBlockType == BlockType.DATA) {
this.dataBlockEncoder.startBlockEncoding(dataBlockEncodingCtx, userDataStream);
}
return userDataStream;
}
/**
* Writes the Cell to this block
*/
void write(Cell cell) throws IOException{
expectState(State.WRITING);
this.dataBlockEncoder.encode(cell, dataBlockEncodingCtx, this.userDataStream);
}
/**
* Transitions the block writer from the "writing" state to the "block
* ready" state. Does nothing if a block is already finished.
*/
void ensureBlockReady() throws IOException {
Preconditions.checkState(state != State.INIT,
"Unexpected state: " + state);
if (state == State.BLOCK_READY) {
return;
}
// This will set state to BLOCK_READY.
finishBlock();
}
/**
* Finish up writing of the block.
* Flushes the compressing stream (if using compression), fills out the header,
* does any compression/encryption of bytes to flush out to disk, and manages
* the cache on write content, if applicable. Sets block write state to "block ready".
*/
private void finishBlock() throws IOException {
if (blockType == BlockType.DATA) {
this.dataBlockEncoder.endBlockEncoding(dataBlockEncodingCtx, userDataStream,
baosInMemory.getBuffer(), blockType);
blockType = dataBlockEncodingCtx.getBlockType();
}
userDataStream.flush();
prevOffset = prevOffsetByType[blockType.getId()];
// We need to set state before we can package the block up for cache-on-write. In a way, the
// block is ready, but not yet encoded or compressed.
state = State.BLOCK_READY;
Bytes compressAndEncryptDat;
if (blockType == BlockType.DATA || blockType == BlockType.ENCODED_DATA) {
compressAndEncryptDat = dataBlockEncodingCtx.
compressAndEncrypt(baosInMemory.getBuffer(), 0, baosInMemory.size());
} else {
compressAndEncryptDat = defaultBlockEncodingCtx.
compressAndEncrypt(baosInMemory.getBuffer(), 0, baosInMemory.size());
}
if (compressAndEncryptDat == null) {
compressAndEncryptDat = new Bytes(baosInMemory.getBuffer(), 0, baosInMemory.size());
}
if (onDiskBlockBytesWithHeader == null) {
onDiskBlockBytesWithHeader = new ByteArrayOutputStream(compressAndEncryptDat.getLength());
}
onDiskBlockBytesWithHeader.reset();
onDiskBlockBytesWithHeader.write(compressAndEncryptDat.get(),
compressAndEncryptDat.getOffset(), compressAndEncryptDat.getLength());
// Calculate how many bytes we need for checksum on the tail of the block.
int numBytes = (int) ChecksumUtil.numBytes(
onDiskBlockBytesWithHeader.size(),
fileContext.getBytesPerChecksum());
// Put the header for the on disk bytes; header currently is unfilled-out
putHeader(onDiskBlockBytesWithHeader,
onDiskBlockBytesWithHeader.size() + numBytes,
baosInMemory.size(), onDiskBlockBytesWithHeader.size());
if (onDiskChecksum.length != numBytes) {
onDiskChecksum = new byte[numBytes];
}
ChecksumUtil.generateChecksums(
onDiskBlockBytesWithHeader.getBuffer(), 0,onDiskBlockBytesWithHeader.size(),
onDiskChecksum, 0, fileContext.getChecksumType(), fileContext.getBytesPerChecksum());
}
/**
* Put the header into the given byte array at the given offset.
* @param onDiskSize size of the block on disk header + data + checksum
* @param uncompressedSize size of the block after decompression (but
* before optional data block decoding) including header
* @param onDiskDataSize size of the block on disk with header
* and data but not including the checksums
*/
private void putHeader(byte[] dest, int offset, int onDiskSize,
int uncompressedSize, int onDiskDataSize) {
offset = blockType.put(dest, offset);
offset = Bytes.putInt(dest, offset, onDiskSize - HConstants.HFILEBLOCK_HEADER_SIZE);
offset = Bytes.putInt(dest, offset, uncompressedSize - HConstants.HFILEBLOCK_HEADER_SIZE);
offset = Bytes.putLong(dest, offset, prevOffset);
offset = Bytes.putByte(dest, offset, fileContext.getChecksumType().getCode());
offset = Bytes.putInt(dest, offset, fileContext.getBytesPerChecksum());
Bytes.putInt(dest, offset, onDiskDataSize);
}
private void putHeader(ByteBuff buff, int onDiskSize,
int uncompressedSize, int onDiskDataSize) {
buff.rewind();
blockType.write(buff);
buff.putInt(onDiskSize - HConstants.HFILEBLOCK_HEADER_SIZE);
buff.putInt(uncompressedSize - HConstants.HFILEBLOCK_HEADER_SIZE);
buff.putLong(prevOffset);
buff.put(fileContext.getChecksumType().getCode());
buff.putInt(fileContext.getBytesPerChecksum());
buff.putInt(onDiskDataSize);
}
private void putHeader(ByteArrayOutputStream dest, int onDiskSize,
int uncompressedSize, int onDiskDataSize) {
putHeader(dest.getBuffer(),0, onDiskSize, uncompressedSize, onDiskDataSize);
}
/**
* Similar to {@link #writeHeaderAndData(FSDataOutputStream)}, but records
* the offset of this block so that it can be referenced in the next block
* of the same type.
*/
void writeHeaderAndData(FSDataOutputStream out) throws IOException {
long offset = out.getPos();
if (startOffset != UNSET && offset != startOffset) {
throw new IOException("A " + blockType + " block written to a "
+ "stream twice, first at offset " + startOffset + ", then at "
+ offset);
}
startOffset = offset;
finishBlockAndWriteHeaderAndData(out);
}
/**
* Writes the header and the compressed data of this block (or uncompressed
* data when not using compression) into the given stream. Can be called in
* the "writing" state or in the "block ready" state. If called in the
* "writing" state, transitions the writer to the "block ready" state.
* @param out the output stream to write the
*/
protected void finishBlockAndWriteHeaderAndData(DataOutputStream out)
throws IOException {
ensureBlockReady();
long startTime = System.currentTimeMillis();
out.write(onDiskBlockBytesWithHeader.getBuffer(), 0, onDiskBlockBytesWithHeader.size());
out.write(onDiskChecksum);
HFile.updateWriteLatency(System.currentTimeMillis() - startTime);
}
/**
* Returns the header or the compressed data (or uncompressed data when not
* using compression) as a byte array. Can be called in the "writing" state
* or in the "block ready" state. If called in the "writing" state,
* transitions the writer to the "block ready" state. This returns
* the header + data + checksums stored on disk.
*
* @return header and data as they would be stored on disk in a byte array
*/
byte[] getHeaderAndDataForTest() throws IOException {
ensureBlockReady();
// This is not very optimal, because we are doing an extra copy.
// But this method is used only by unit tests.
byte[] output =
new byte[onDiskBlockBytesWithHeader.size()
+ onDiskChecksum.length];
System.arraycopy(onDiskBlockBytesWithHeader.getBuffer(), 0, output, 0,
onDiskBlockBytesWithHeader.size());
System.arraycopy(onDiskChecksum, 0, output,
onDiskBlockBytesWithHeader.size(), onDiskChecksum.length);
return output;
}
/**
* Releases resources used by this writer.
*/
void release() {
if (dataBlockEncodingCtx != null) {
dataBlockEncodingCtx.close();
dataBlockEncodingCtx = null;
}
if (defaultBlockEncodingCtx != null) {
defaultBlockEncodingCtx.close();
defaultBlockEncodingCtx = null;
}
}
/**
* Returns the on-disk size of the data portion of the block. This is the
* compressed size if compression is enabled. Can only be called in the
* "block ready" state. Header is not compressed, and its size is not
* included in the return value.
*
* @return the on-disk size of the block, not including the header.
*/
int getOnDiskSizeWithoutHeader() {
expectState(State.BLOCK_READY);
return onDiskBlockBytesWithHeader.size() +
onDiskChecksum.length - HConstants.HFILEBLOCK_HEADER_SIZE;
}
/**
* Returns the on-disk size of the block. Can only be called in the
* "block ready" state.
*
* @return the on-disk size of the block ready to be written, including the
* header size, the data and the checksum data.
*/
int getOnDiskSizeWithHeader() {
expectState(State.BLOCK_READY);
return onDiskBlockBytesWithHeader.size() + onDiskChecksum.length;
}
/**
* The uncompressed size of the block data. Does not include header size.
*/
int getUncompressedSizeWithoutHeader() {
expectState(State.BLOCK_READY);
return baosInMemory.size() - HConstants.HFILEBLOCK_HEADER_SIZE;
}
/**
* The uncompressed size of the block data, including header size.
*/
int getUncompressedSizeWithHeader() {
expectState(State.BLOCK_READY);
return baosInMemory.size();
}
/** @return true if a block is being written */
boolean isWriting() {
return state == State.WRITING;
}
/**
* Returns the number of bytes written into the current block so far, or
* zero if not writing the block at the moment. Note that this will return
* zero in the "block ready" state as well.
*
* @return the number of bytes written
*/
public int encodedBlockSizeWritten() {
return state != State.WRITING ? 0 : this.getEncodingState().getEncodedDataSizeWritten();
}
/**
* Returns the number of bytes written into the current block so far, or
* zero if not writing the block at the moment. Note that this will return
* zero in the "block ready" state as well.
*
* @return the number of bytes written
*/
int blockSizeWritten() {
return state != State.WRITING ? 0 : this.getEncodingState().getUnencodedDataSizeWritten();
}
/**
* Clones the header followed by the uncompressed data, even if using
* compression. This is needed for storing uncompressed blocks in the block
* cache. Can be called in the "writing" state or the "block ready" state.
* Returns only the header and data, does not include checksum data.
*
* @return Returns an uncompressed block ByteBuff for caching on write
*/
ByteBuff cloneUncompressedBufferWithHeader() {
expectState(State.BLOCK_READY);
ByteBuff bytebuff = allocator.allocate(baosInMemory.size());
baosInMemory.toByteBuff(bytebuff);
int numBytes = (int) ChecksumUtil.numBytes(
onDiskBlockBytesWithHeader.size(),
fileContext.getBytesPerChecksum());
putHeader(bytebuff, onDiskBlockBytesWithHeader.size() + numBytes,
baosInMemory.size(), onDiskBlockBytesWithHeader.size());
bytebuff.rewind();
return bytebuff;
}
/**
* Clones the header followed by the on-disk (compressed/encoded/encrypted) data. This is needed
* for storing packed blocks in the block cache. Returns only the header and data, Does not
* include checksum data.
* @return Returns a copy of block bytes for caching on write
*/
private ByteBuff cloneOnDiskBufferWithHeader() {
expectState(State.BLOCK_READY);
ByteBuff bytebuff = allocator.allocate(onDiskBlockBytesWithHeader.size());
onDiskBlockBytesWithHeader.toByteBuff(bytebuff);
bytebuff.rewind();
return bytebuff;
}
private void expectState(State expectedState) {
if (state != expectedState) {
throw new IllegalStateException("Expected state: " + expectedState +
", actual state: " + state);
}
}
/**
* Takes the given {@link BlockWritable} instance, creates a new block of
* its appropriate type, writes the writable into this block, and flushes
* the block into the output stream. The writer is instructed not to buffer
* uncompressed bytes for cache-on-write.
*
* @param bw the block-writable object to write as a block
* @param out the file system output stream
*/
void writeBlock(BlockWritable bw, FSDataOutputStream out)
throws IOException {
bw.writeToBlock(startWriting(bw.getBlockType()));
writeHeaderAndData(out);
}
/**
* Creates a new HFileBlock. Checksums have already been validated, so
* the byte buffer passed into the constructor of this newly created
* block does not have checksum data even though the header minor
* version is MINOR_VERSION_WITH_CHECKSUM. This is indicated by setting a
* 0 value in bytesPerChecksum. This method copies the on-disk or
* uncompressed data to build the HFileBlock which is used only
* while writing blocks and caching.
*
*
TODO: Should there be an option where a cache can ask that hbase preserve block
* checksums for checking after a block comes out of the cache? Otehrwise, cache is responsible
* for blocks being wholesome (ECC memory or if file-backed, it does checksumming).
*/
HFileBlock getBlockForCaching(CacheConfig cacheConf) {
HFileContext newContext = new HFileContextBuilder()
.withBlockSize(fileContext.getBlocksize())
.withBytesPerCheckSum(0)
.withChecksumType(ChecksumType.NULL) // no checksums in cached data
.withCompression(fileContext.getCompression())
.withDataBlockEncoding(fileContext.getDataBlockEncoding())
.withHBaseCheckSum(fileContext.isUseHBaseChecksum())
.withCompressTags(fileContext.isCompressTags())
.withIncludesMvcc(fileContext.isIncludesMvcc())
.withIncludesTags(fileContext.isIncludesTags())
.withColumnFamily(fileContext.getColumnFamily())
.withTableName(fileContext.getTableName())
.build();
// Build the HFileBlock.
HFileBlockBuilder builder = new HFileBlockBuilder();
ByteBuff buff;
if (cacheConf.shouldCacheCompressed(blockType.getCategory())) {
buff = cloneOnDiskBufferWithHeader();
} else {
buff = cloneUncompressedBufferWithHeader();
}
return builder.withBlockType(blockType)
.withOnDiskSizeWithoutHeader(getOnDiskSizeWithoutHeader())
.withUncompressedSizeWithoutHeader(getUncompressedSizeWithoutHeader())
.withPrevBlockOffset(prevOffset)
.withByteBuff(buff)
.withFillHeader(FILL_HEADER)
.withOffset(startOffset)
.withNextBlockOnDiskSize(UNSET)
.withOnDiskDataSizeWithHeader(onDiskBlockBytesWithHeader.size() + onDiskChecksum.length)
.withHFileContext(newContext)
.withByteBuffAllocator(cacheConf.getByteBuffAllocator())
.withShared(!buff.hasArray())
.build();
}
}
/** Something that can be written into a block. */
interface BlockWritable {
/** The type of block this data should use. */
BlockType getBlockType();
/**
* Writes the block to the provided stream. Must not write any magic
* records.
*
* @param out a stream to write uncompressed data into
*/
void writeToBlock(DataOutput out) throws IOException;
}
/**
* Iterator for reading {@link HFileBlock}s in load-on-open-section, such as root data index
* block, meta index block, file info block etc.
*/
interface BlockIterator {
/**
* Get the next block, or null if there are no more blocks to iterate.
*/
HFileBlock nextBlock() throws IOException;
/**
* Similar to {@link #nextBlock()} but checks block type, throws an exception if incorrect, and
* returns the HFile block
*/
HFileBlock nextBlockWithBlockType(BlockType blockType) throws IOException;
/**
* Now we use the {@link ByteBuffAllocator} to manage the nio ByteBuffers for HFileBlocks, so we
* must deallocate all of the ByteBuffers in the end life. the BlockIterator's life cycle is
* starting from opening an HFileReader and stopped when the HFileReader#close, so we will keep
* track all the read blocks until we call {@link BlockIterator#freeBlocks()} when closing the
* HFileReader. Sum bytes of those blocks in load-on-open section should be quite small, so
* tracking them should be OK.
*/
void freeBlocks();
}
/** An HFile block reader with iteration ability. */
interface FSReader {
/**
* Reads the block at the given offset in the file with the given on-disk size and uncompressed
* size.
* @param offset of the file to read
* @param onDiskSize the on-disk size of the entire block, including all applicable headers, or
* -1 if unknown
* @param pread true to use pread, otherwise use the stream read.
* @param updateMetrics update the metrics or not.
* @param intoHeap allocate the block's ByteBuff by {@link ByteBuffAllocator} or JVM heap. For
* LRUBlockCache, we must ensure that the block to cache is an heap one, because the
* memory occupation is based on heap now, also for {@link CombinedBlockCache}, we use
* the heap LRUBlockCache as L1 cache to cache small blocks such as IndexBlock or
* MetaBlock for faster access. So introduce an flag here to decide whether allocate
* from JVM heap or not so that we can avoid an extra off-heap to heap memory copy when
* using LRUBlockCache. For most cases, we known what's the expected block type we'll
* read, while for some special case (Example: HFileReaderImpl#readNextDataBlock()), we
* cannot pre-decide what's the expected block type, then we can only allocate block's
* ByteBuff from {@link ByteBuffAllocator} firstly, and then when caching it in
* {@link LruBlockCache} we'll check whether the ByteBuff is from heap or not, if not
* then we'll clone it to an heap one and cache it.
* @return the newly read block
*/
HFileBlock readBlockData(long offset, long onDiskSize, boolean pread, boolean updateMetrics,
boolean intoHeap) throws IOException;
/**
* Creates a block iterator over the given portion of the {@link HFile}.
* The iterator returns blocks starting with offset such that offset <=
* startOffset < endOffset. Returned blocks are always unpacked.
* Used when no hfile index available; e.g. reading in the hfile index
* blocks themselves on file open.
*
* @param startOffset the offset of the block to start iteration with
* @param endOffset the offset to end iteration at (exclusive)
* @return an iterator of blocks between the two given offsets
*/
BlockIterator blockRange(long startOffset, long endOffset);
/** Closes the backing streams */
void closeStreams() throws IOException;
/** Get a decoder for {@link BlockType#ENCODED_DATA} blocks from this file. */
HFileBlockDecodingContext getBlockDecodingContext();
/** Get the default decoder for blocks from this file. */
HFileBlockDecodingContext getDefaultBlockDecodingContext();
void setIncludesMemStoreTS(boolean includesMemstoreTS);
void setDataBlockEncoder(HFileDataBlockEncoder encoder);
/**
* To close the stream's socket. Note: This can be concurrently called from multiple threads and
* implementation should take care of thread safety.
*/
void unbufferStream();
}
/**
* Data-structure to use caching the header of the NEXT block. Only works if next read
* that comes in here is next in sequence in this block.
*
* When we read, we read current block and the next blocks' header. We do this so we have
* the length of the next block to read if the hfile index is not available (rare, at
* hfile open only).
*/
private static class PrefetchedHeader {
long offset = -1;
byte[] header = new byte[HConstants.HFILEBLOCK_HEADER_SIZE];
final ByteBuff buf = new SingleByteBuff(ByteBuffer.wrap(header, 0, header.length));
@Override
public String toString() {
return "offset=" + this.offset + ", header=" + Bytes.toStringBinary(header);
}
}
/**
* Reads version 2 HFile blocks from the filesystem.
*/
static class FSReaderImpl implements FSReader {
/** The file system stream of the underlying {@link HFile} that
* does or doesn't do checksum validations in the filesystem */
private FSDataInputStreamWrapper streamWrapper;
private HFileBlockDecodingContext encodedBlockDecodingCtx;
/** Default context used when BlockType != {@link BlockType#ENCODED_DATA}. */
private final HFileBlockDefaultDecodingContext defaultDecodingCtx;
/**
* Cache of the NEXT header after this. Check it is indeed next blocks header
* before using it. TODO: Review. This overread into next block to fetch
* next blocks header seems unnecessary given we usually get the block size
* from the hfile index. Review!
*/
private AtomicReference prefetchedHeader =
new AtomicReference<>(new PrefetchedHeader());
/** The size of the file we are reading from, or -1 if unknown. */
private long fileSize;
/** The size of the header */
protected final int hdrSize;
/** The filesystem used to access data */
private HFileSystem hfs;
private HFileContext fileContext;
// Cache the fileName
private String pathName;
private final ByteBuffAllocator allocator;
private final Lock streamLock = new ReentrantLock();
FSReaderImpl(ReaderContext readerContext, HFileContext fileContext,
ByteBuffAllocator allocator) throws IOException {
this.fileSize = readerContext.getFileSize();
this.hfs = readerContext.getFileSystem();
if (readerContext.getFilePath() != null) {
this.pathName = readerContext.getFilePath().toString();
}
this.fileContext = fileContext;
this.hdrSize = headerSize(fileContext.isUseHBaseChecksum());
this.allocator = allocator;
this.streamWrapper = readerContext.getInputStreamWrapper();
// Older versions of HBase didn't support checksum.
this.streamWrapper.prepareForBlockReader(!fileContext.isUseHBaseChecksum());
defaultDecodingCtx = new HFileBlockDefaultDecodingContext(fileContext);
encodedBlockDecodingCtx = defaultDecodingCtx;
}
@Override
public BlockIterator blockRange(final long startOffset, final long endOffset) {
final FSReader owner = this; // handle for inner class
return new BlockIterator() {
private volatile boolean freed = false;
// Tracking all read blocks until we call freeBlocks.
private List blockTracker = new ArrayList<>();
private long offset = startOffset;
// Cache length of next block. Current block has the length of next block in it.
private long length = -1;
@Override
public HFileBlock nextBlock() throws IOException {
if (offset >= endOffset) {
return null;
}
HFileBlock b = readBlockData(offset, length, false, false, true);
offset += b.getOnDiskSizeWithHeader();
length = b.getNextBlockOnDiskSize();
HFileBlock uncompressed = b.unpack(fileContext, owner);
if (uncompressed != b) {
b.release(); // Need to release the compressed Block now.
}
blockTracker.add(uncompressed);
return uncompressed;
}
@Override
public HFileBlock nextBlockWithBlockType(BlockType blockType) throws IOException {
HFileBlock blk = nextBlock();
if (blk.getBlockType() != blockType) {
throw new IOException(
"Expected block of type " + blockType + " but found " + blk.getBlockType());
}
return blk;
}
@Override
public void freeBlocks() {
if (freed) {
return;
}
blockTracker.forEach(HFileBlock::release);
blockTracker = null;
freed = true;
}
};
}
/**
* Does a positional read or a seek and read into the given byte buffer. We need take care that
* we will call the {@link ByteBuff#release()} for every exit to deallocate the ByteBuffers,
* otherwise the memory leak may happen.
* @param dest destination buffer
* @param size size of read
* @param peekIntoNextBlock whether to read the next block's on-disk size
* @param fileOffset position in the stream to read at
* @param pread whether we should do a positional read
* @param istream The input source of data
* @return true to indicate the destination buffer include the next block header, otherwise only
* include the current block data without the next block header.
* @throws IOException if any IO error happen.
*/
protected boolean readAtOffset(FSDataInputStream istream, ByteBuff dest, int size,
boolean peekIntoNextBlock, long fileOffset, boolean pread) throws IOException {
if (!pread) {
// Seek + read. Better for scanning.
HFileUtil.seekOnMultipleSources(istream, fileOffset);
long realOffset = istream.getPos();
if (realOffset != fileOffset) {
throw new IOException("Tried to seek to " + fileOffset + " to read " + size
+ " bytes, but pos=" + realOffset + " after seek");
}
if (!peekIntoNextBlock) {
BlockIOUtils.readFully(dest, istream, size);
return false;
}
// Try to read the next block header
if (!BlockIOUtils.readWithExtra(dest, istream, size, hdrSize)) {
// did not read the next block header.
return false;
}
} else {
// Positional read. Better for random reads; or when the streamLock is already locked.
int extraSize = peekIntoNextBlock ? hdrSize : 0;
if (!BlockIOUtils.preadWithExtra(dest, istream, fileOffset, size, extraSize)) {
// did not read the next block header.
return false;
}
}
assert peekIntoNextBlock;
return true;
}
/**
* Reads a version 2 block (version 1 blocks not supported and not expected). Tries to do as
* little memory allocation as possible, using the provided on-disk size.
* @param offset the offset in the stream to read at
* @param onDiskSizeWithHeaderL the on-disk size of the block, including the header, or -1 if
* unknown; i.e. when iterating over blocks reading in the file metadata info.
* @param pread whether to use a positional read
* @param updateMetrics whether to update the metrics
* @param intoHeap allocate ByteBuff of block from heap or off-heap.
* @see FSReader#readBlockData(long, long, boolean, boolean, boolean) for more details about the
* useHeap.
*/
@Override
public HFileBlock readBlockData(long offset, long onDiskSizeWithHeaderL, boolean pread,
boolean updateMetrics, boolean intoHeap) throws IOException {
// Get a copy of the current state of whether to validate
// hbase checksums or not for this read call. This is not
// thread-safe but the one constaint is that if we decide
// to skip hbase checksum verification then we are
// guaranteed to use hdfs checksum verification.
boolean doVerificationThruHBaseChecksum = streamWrapper.shouldUseHBaseChecksum();
FSDataInputStream is = streamWrapper.getStream(doVerificationThruHBaseChecksum);
HFileBlock blk = readBlockDataInternal(is, offset, onDiskSizeWithHeaderL, pread,
doVerificationThruHBaseChecksum, updateMetrics, intoHeap);
if (blk == null) {
HFile.LOG.warn("HBase checksum verification failed for file " +
pathName + " at offset " +
offset + " filesize " + fileSize +
". Retrying read with HDFS checksums turned on...");
if (!doVerificationThruHBaseChecksum) {
String msg = "HBase checksum verification failed for file " +
pathName + " at offset " +
offset + " filesize " + fileSize +
" but this cannot happen because doVerify is " +
doVerificationThruHBaseChecksum;
HFile.LOG.warn(msg);
throw new IOException(msg); // cannot happen case here
}
HFile.CHECKSUM_FAILURES.increment(); // update metrics
// If we have a checksum failure, we fall back into a mode where
// the next few reads use HDFS level checksums. We aim to make the
// next CHECKSUM_VERIFICATION_NUM_IO_THRESHOLD reads avoid
// hbase checksum verification, but since this value is set without
// holding any locks, it can so happen that we might actually do
// a few more than precisely this number.
is = this.streamWrapper.fallbackToFsChecksum(CHECKSUM_VERIFICATION_NUM_IO_THRESHOLD);
doVerificationThruHBaseChecksum = false;
blk = readBlockDataInternal(is, offset, onDiskSizeWithHeaderL, pread,
doVerificationThruHBaseChecksum, updateMetrics, intoHeap);
if (blk != null) {
HFile.LOG.warn("HDFS checksum verification succeeded for file " +
pathName + " at offset " +
offset + " filesize " + fileSize);
}
}
if (blk == null && !doVerificationThruHBaseChecksum) {
String msg = "readBlockData failed, possibly due to " +
"checksum verification failed for file " + pathName +
" at offset " + offset + " filesize " + fileSize;
HFile.LOG.warn(msg);
throw new IOException(msg);
}
// If there is a checksum mismatch earlier, then retry with
// HBase checksums switched off and use HDFS checksum verification.
// This triggers HDFS to detect and fix corrupt replicas. The
// next checksumOffCount read requests will use HDFS checksums.
// The decrementing of this.checksumOffCount is not thread-safe,
// but it is harmless because eventually checksumOffCount will be
// a negative number.
streamWrapper.checksumOk();
return blk;
}
/**
* @return Check onDiskSizeWithHeaderL size is healthy and then return it as an int
*/
private static int checkAndGetSizeAsInt(final long onDiskSizeWithHeaderL, final int hdrSize)
throws IOException {
if ((onDiskSizeWithHeaderL < hdrSize && onDiskSizeWithHeaderL != -1)
|| onDiskSizeWithHeaderL >= Integer.MAX_VALUE) {
throw new IOException("Invalid onDisksize=" + onDiskSizeWithHeaderL
+ ": expected to be at least " + hdrSize
+ " and at most " + Integer.MAX_VALUE + ", or -1");
}
return (int)onDiskSizeWithHeaderL;
}
/**
* Verify the passed in onDiskSizeWithHeader aligns with what is in the header else something
* is not right.
*/
private void verifyOnDiskSizeMatchesHeader(final int passedIn, final ByteBuff headerBuf,
final long offset, boolean verifyChecksum)
throws IOException {
// Assert size provided aligns with what is in the header
int fromHeader = getOnDiskSizeWithHeader(headerBuf, verifyChecksum);
if (passedIn != fromHeader) {
throw new IOException("Passed in onDiskSizeWithHeader=" + passedIn + " != " + fromHeader +
", offset=" + offset + ", fileContext=" + this.fileContext);
}
}
/**
* Check atomic reference cache for this block's header. Cache only good if next
* read coming through is next in sequence in the block. We read next block's
* header on the tail of reading the previous block to save a seek. Otherwise,
* we have to do a seek to read the header before we can pull in the block OR
* we have to backup the stream because we over-read (the next block's header).
* @see PrefetchedHeader
* @return The cached block header or null if not found.
* @see #cacheNextBlockHeader(long, ByteBuff, int, int)
*/
private ByteBuff getCachedHeader(final long offset) {
PrefetchedHeader ph = this.prefetchedHeader.get();
return ph != null && ph.offset == offset ? ph.buf : null;
}
/**
* Save away the next blocks header in atomic reference.
* @see #getCachedHeader(long)
* @see PrefetchedHeader
*/
private void cacheNextBlockHeader(final long offset,
ByteBuff onDiskBlock, int onDiskSizeWithHeader, int headerLength) {
PrefetchedHeader ph = new PrefetchedHeader();
ph.offset = offset;
onDiskBlock.get(onDiskSizeWithHeader, ph.header, 0, headerLength);
this.prefetchedHeader.set(ph);
}
private int getNextBlockOnDiskSize(boolean readNextHeader, ByteBuff onDiskBlock,
int onDiskSizeWithHeader) {
int nextBlockOnDiskSize = -1;
if (readNextHeader) {
nextBlockOnDiskSize =
onDiskBlock.getIntAfterPosition(onDiskSizeWithHeader + BlockType.MAGIC_LENGTH)
+ hdrSize;
}
return nextBlockOnDiskSize;
}
private ByteBuff allocate(int size, boolean intoHeap) {
return intoHeap ? HEAP.allocate(size) : allocator.allocate(size);
}
/**
* Reads a version 2 block.
* @param offset the offset in the stream to read at.
* @param onDiskSizeWithHeaderL the on-disk size of the block, including the header and
* checksums if present or -1 if unknown (as a long). Can be -1 if we are doing raw
* iteration of blocks as when loading up file metadata; i.e. the first read of a new
* file. Usually non-null gotten from the file index.
* @param pread whether to use a positional read
* @param verifyChecksum Whether to use HBase checksums. If HBase checksum is switched off, then
* use HDFS checksum. Can also flip on/off reading same file if we hit a troublesome
* patch in an hfile.
* @param updateMetrics whether need to update the metrics.
* @param intoHeap allocate the ByteBuff of block from heap or off-heap.
* @return the HFileBlock or null if there is a HBase checksum mismatch
*/
protected HFileBlock readBlockDataInternal(FSDataInputStream is, long offset,
long onDiskSizeWithHeaderL, boolean pread, boolean verifyChecksum, boolean updateMetrics,
boolean intoHeap) throws IOException {
if (offset < 0) {
throw new IOException("Invalid offset=" + offset + " trying to read "
+ "block (onDiskSize=" + onDiskSizeWithHeaderL + ")");
}
int onDiskSizeWithHeader = checkAndGetSizeAsInt(onDiskSizeWithHeaderL, hdrSize);
// Try and get cached header. Will serve us in rare case where onDiskSizeWithHeaderL is -1
// and will save us having to seek the stream backwards to reread the header we
// read the last time through here.
ByteBuff headerBuf = getCachedHeader(offset);
LOG.trace("Reading {} at offset={}, pread={}, verifyChecksum={}, cachedHeader={}, " +
"onDiskSizeWithHeader={}", this.fileContext.getHFileName(), offset, pread,
verifyChecksum, headerBuf, onDiskSizeWithHeader);
// This is NOT same as verifyChecksum. This latter is whether to do hbase
// checksums. Can change with circumstances. The below flag is whether the
// file has support for checksums (version 2+).
boolean checksumSupport = this.fileContext.isUseHBaseChecksum();
long startTime = System.currentTimeMillis();
if (onDiskSizeWithHeader <= 0) {
// We were not passed the block size. Need to get it from the header. If header was
// not cached (see getCachedHeader above), need to seek to pull it in. This is costly
// and should happen very rarely. Currently happens on open of a hfile reader where we
// read the trailer blocks to pull in the indices. Otherwise, we are reading block sizes
// out of the hfile index. To check, enable TRACE in this file and you'll get an exception
// in a LOG every time we seek. See HBASE-17072 for more detail.
if (headerBuf == null) {
if (LOG.isTraceEnabled()) {
LOG.trace("Extra see to get block size!", new RuntimeException());
}
headerBuf = HEAP.allocate(hdrSize);
readAtOffset(is, headerBuf, hdrSize, false, offset, pread);
headerBuf.rewind();
}
onDiskSizeWithHeader = getOnDiskSizeWithHeader(headerBuf, checksumSupport);
}
int preReadHeaderSize = headerBuf == null? 0 : hdrSize;
// Allocate enough space to fit the next block's header too; saves a seek next time through.
// onDiskBlock is whole block + header + checksums then extra hdrSize to read next header;
// onDiskSizeWithHeader is header, body, and any checksums if present. preReadHeaderSize
// says where to start reading. If we have the header cached, then we don't need to read
// it again and we can likely read from last place we left off w/o need to backup and reread
// the header we read last time through here.
ByteBuff onDiskBlock = this.allocate(onDiskSizeWithHeader + hdrSize, intoHeap);
boolean initHFileBlockSuccess = false;
try {
if (headerBuf != null) {
onDiskBlock.put(0, headerBuf, 0, hdrSize).position(hdrSize);
}
boolean readNextHeader = readAtOffset(is, onDiskBlock,
onDiskSizeWithHeader - preReadHeaderSize, true, offset + preReadHeaderSize, pread);
onDiskBlock.rewind(); // in case of moving position when copying a cached header
int nextBlockOnDiskSize =
getNextBlockOnDiskSize(readNextHeader, onDiskBlock, onDiskSizeWithHeader);
if (headerBuf == null) {
headerBuf = onDiskBlock.duplicate().position(0).limit(hdrSize);
}
// Do a few checks before we go instantiate HFileBlock.
assert onDiskSizeWithHeader > this.hdrSize;
verifyOnDiskSizeMatchesHeader(onDiskSizeWithHeader, headerBuf, offset, checksumSupport);
ByteBuff curBlock = onDiskBlock.duplicate().position(0).limit(onDiskSizeWithHeader);
// Verify checksum of the data before using it for building HFileBlock.
if (verifyChecksum && !validateChecksum(offset, curBlock, hdrSize)) {
return null;
}
long duration = System.currentTimeMillis() - startTime;
if (updateMetrics) {
HFile.updateReadLatency(duration, pread);
}
// The onDiskBlock will become the headerAndDataBuffer for this block.
// If nextBlockOnDiskSizeWithHeader is not zero, the onDiskBlock already
// contains the header of next block, so no need to set next block's header in it.
HFileBlock hFileBlock = createFromBuff(curBlock, checksumSupport, offset,
nextBlockOnDiskSize, fileContext, intoHeap ? HEAP : allocator);
// Run check on uncompressed sizings.
if (!fileContext.isCompressedOrEncrypted()) {
hFileBlock.sanityCheckUncompressed();
}
LOG.trace("Read {} in {} ns", hFileBlock, duration);
// Cache next block header if we read it for the next time through here.
if (nextBlockOnDiskSize != -1) {
cacheNextBlockHeader(offset + hFileBlock.getOnDiskSizeWithHeader(), onDiskBlock,
onDiskSizeWithHeader, hdrSize);
}
initHFileBlockSuccess = true;
return hFileBlock;
} finally {
if (!initHFileBlockSuccess) {
onDiskBlock.release();
}
}
}
@Override
public void setIncludesMemStoreTS(boolean includesMemstoreTS) {
this.fileContext = new HFileContextBuilder(this.fileContext)
.withIncludesMvcc(includesMemstoreTS).build();
}
@Override
public void setDataBlockEncoder(HFileDataBlockEncoder encoder) {
encodedBlockDecodingCtx = encoder.newDataBlockDecodingContext(this.fileContext);
}
@Override
public HFileBlockDecodingContext getBlockDecodingContext() {
return this.encodedBlockDecodingCtx;
}
@Override
public HFileBlockDecodingContext getDefaultBlockDecodingContext() {
return this.defaultDecodingCtx;
}
/**
* Generates the checksum for the header as well as the data and then validates it.
* If the block doesn't uses checksum, returns false.
* @return True if checksum matches, else false.
*/
private boolean validateChecksum(long offset, ByteBuff data, int hdrSize) {
// If this is an older version of the block that does not have checksums, then return false
// indicating that checksum verification did not succeed. Actually, this method should never
// be called when the minorVersion is 0, thus this is a defensive check for a cannot-happen
// case. Since this is a cannot-happen case, it is better to return false to indicate a
// checksum validation failure.
if (!fileContext.isUseHBaseChecksum()) {
return false;
}
return ChecksumUtil.validateChecksum(data, pathName, offset, hdrSize);
}
@Override
public void closeStreams() throws IOException {
streamWrapper.close();
}
@Override
public void unbufferStream() {
// To handle concurrent reads, ensure that no other client is accessing the streams while we
// unbuffer it.
if (streamLock.tryLock()) {
try {
this.streamWrapper.unbuffer();
} finally {
streamLock.unlock();
}
}
}
@Override
public String toString() {
return "hfs=" + hfs + ", path=" + pathName + ", fileContext=" + fileContext;
}
}
/** An additional sanity-check in case no compression or encryption is being used. */
void sanityCheckUncompressed() throws IOException {
if (onDiskSizeWithoutHeader != uncompressedSizeWithoutHeader +
totalChecksumBytes()) {
throw new IOException("Using no compression but "
+ "onDiskSizeWithoutHeader=" + onDiskSizeWithoutHeader + ", "
+ "uncompressedSizeWithoutHeader=" + uncompressedSizeWithoutHeader
+ ", numChecksumbytes=" + totalChecksumBytes());
}
}
// Cacheable implementation
@Override
public int getSerializedLength() {
if (buf != null) {
// Include extra bytes for block metadata.
return this.buf.limit() + BLOCK_METADATA_SPACE;
}
return 0;
}
// Cacheable implementation
@Override
public void serialize(ByteBuffer destination, boolean includeNextBlockMetadata) {
this.buf.get(destination, 0, getSerializedLength() - BLOCK_METADATA_SPACE);
destination = addMetaData(destination, includeNextBlockMetadata);
// Make it ready for reading. flip sets position to zero and limit to current position which
// is what we want if we do not want to serialize the block plus checksums if present plus
// metadata.
destination.flip();
}
/**
* For use by bucketcache. This exposes internals.
*/
public ByteBuffer getMetaData() {
ByteBuffer bb = ByteBuffer.allocate(BLOCK_METADATA_SPACE);
bb = addMetaData(bb, true);
bb.flip();
return bb;
}
/**
* Adds metadata at current position (position is moved forward). Does not flip or reset.
* @return The passed destination with metadata added.
*/
private ByteBuffer addMetaData(final ByteBuffer destination, boolean includeNextBlockMetadata) {
destination.put(this.fileContext.isUseHBaseChecksum() ? (byte) 1 : (byte) 0);
destination.putLong(this.offset);
if (includeNextBlockMetadata) {
destination.putInt(this.nextBlockOnDiskSize);
}
return destination;
}
// Cacheable implementation
@Override
public CacheableDeserializer getDeserializer() {
return HFileBlock.BLOCK_DESERIALIZER;
}
@Override
public int hashCode() {
int result = 1;
result = result * 31 + blockType.hashCode();
result = result * 31 + nextBlockOnDiskSize;
result = result * 31 + (int) (offset ^ (offset >>> 32));
result = result * 31 + onDiskSizeWithoutHeader;
result = result * 31 + (int) (prevBlockOffset ^ (prevBlockOffset >>> 32));
result = result * 31 + uncompressedSizeWithoutHeader;
result = result * 31 + buf.hashCode();
return result;
}
@Override
public boolean equals(Object comparison) {
if (this == comparison) {
return true;
}
if (comparison == null) {
return false;
}
if (!(comparison instanceof HFileBlock)) {
return false;
}
HFileBlock castedComparison = (HFileBlock) comparison;
if (castedComparison.blockType != this.blockType) {
return false;
}
if (castedComparison.nextBlockOnDiskSize != this.nextBlockOnDiskSize) {
return false;
}
// Offset is important. Needed when we have to remake cachekey when block is returned to cache.
if (castedComparison.offset != this.offset) {
return false;
}
if (castedComparison.onDiskSizeWithoutHeader != this.onDiskSizeWithoutHeader) {
return false;
}
if (castedComparison.prevBlockOffset != this.prevBlockOffset) {
return false;
}
if (castedComparison.uncompressedSizeWithoutHeader != this.uncompressedSizeWithoutHeader) {
return false;
}
if (ByteBuff.compareTo(this.buf, 0, this.buf.limit(), castedComparison.buf, 0,
castedComparison.buf.limit()) != 0) {
return false;
}
return true;
}
DataBlockEncoding getDataBlockEncoding() {
if (blockType == BlockType.ENCODED_DATA) {
return DataBlockEncoding.getEncodingById(getDataBlockEncodingId());
}
return DataBlockEncoding.NONE;
}
byte getChecksumType() {
return this.fileContext.getChecksumType().getCode();
}
int getBytesPerChecksum() {
return this.fileContext.getBytesPerChecksum();
}
/** @return the size of data on disk + header. Excludes checksum. */
int getOnDiskDataSizeWithHeader() {
return this.onDiskDataSizeWithHeader;
}
/**
* Calculate the number of bytes required to store all the checksums
* for this block. Each checksum value is a 4 byte integer.
*/
int totalChecksumBytes() {
// If the hfile block has minorVersion 0, then there are no checksum
// data to validate. Similarly, a zero value in this.bytesPerChecksum
// indicates that cached blocks do not have checksum data because
// checksums were already validated when the block was read from disk.
if (!fileContext.isUseHBaseChecksum() || this.fileContext.getBytesPerChecksum() == 0) {
return 0;
}
return (int) ChecksumUtil.numBytes(onDiskDataSizeWithHeader,
this.fileContext.getBytesPerChecksum());
}
/**
* Returns the size of this block header.
*/
public int headerSize() {
return headerSize(this.fileContext.isUseHBaseChecksum());
}
/**
* Maps a minor version to the size of the header.
*/
public static int headerSize(boolean usesHBaseChecksum) {
return usesHBaseChecksum?
HConstants.HFILEBLOCK_HEADER_SIZE: HConstants.HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM;
}
/**
* Return the appropriate DUMMY_HEADER for the minor version
*/
// TODO: Why is this in here?
byte[] getDummyHeaderForVersion() {
return getDummyHeaderForVersion(this.fileContext.isUseHBaseChecksum());
}
/**
* Return the appropriate DUMMY_HEADER for the minor version
*/
static private byte[] getDummyHeaderForVersion(boolean usesHBaseChecksum) {
return usesHBaseChecksum? HConstants.HFILEBLOCK_DUMMY_HEADER: DUMMY_HEADER_NO_CHECKSUM;
}
/**
* @return This HFileBlocks fileContext which will a derivative of the
* fileContext for the file from which this block's data was originally read.
*/
HFileContext getHFileContext() {
return this.fileContext;
}
/**
* Convert the contents of the block header into a human readable string.
* This is mostly helpful for debugging. This assumes that the block
* has minor version > 0.
*/
static String toStringHeader(ByteBuff buf) throws IOException {
byte[] magicBuf = new byte[Math.min(buf.limit() - buf.position(), BlockType.MAGIC_LENGTH)];
buf.get(magicBuf);
BlockType bt = BlockType.parse(magicBuf, 0, BlockType.MAGIC_LENGTH);
int compressedBlockSizeNoHeader = buf.getInt();
int uncompressedBlockSizeNoHeader = buf.getInt();
long prevBlockOffset = buf.getLong();
byte cksumtype = buf.get();
long bytesPerChecksum = buf.getInt();
long onDiskDataSizeWithHeader = buf.getInt();
return " Header dump: magic: " + Bytes.toString(magicBuf) +
" blockType " + bt +
" compressedBlockSizeNoHeader " +
compressedBlockSizeNoHeader +
" uncompressedBlockSizeNoHeader " +
uncompressedBlockSizeNoHeader +
" prevBlockOffset " + prevBlockOffset +
" checksumType " + ChecksumType.codeToType(cksumtype) +
" bytesPerChecksum " + bytesPerChecksum +
" onDiskDataSizeWithHeader " + onDiskDataSizeWithHeader;
}
private static HFileBlockBuilder createBuilder(HFileBlock blk){
return new HFileBlockBuilder()
.withBlockType(blk.blockType)
.withOnDiskSizeWithoutHeader(blk.onDiskSizeWithoutHeader)
.withUncompressedSizeWithoutHeader(blk.uncompressedSizeWithoutHeader)
.withPrevBlockOffset(blk.prevBlockOffset)
.withByteBuff(blk.buf.duplicate()) // Duplicate the buffer.
.withOffset(blk.offset)
.withOnDiskDataSizeWithHeader(blk.onDiskDataSizeWithHeader)
.withNextBlockOnDiskSize(blk.nextBlockOnDiskSize)
.withHFileContext(blk.fileContext)
.withByteBuffAllocator(blk.allocator)
.withShared(blk.isSharedMem());
}
static HFileBlock shallowClone(HFileBlock blk) {
return createBuilder(blk).build();
}
static HFileBlock deepCloneOnHeap(HFileBlock blk) {
ByteBuff deepCloned = ByteBuff.wrap(ByteBuffer.wrap(blk.buf.toBytes(0, blk.buf.limit())));
return createBuilder(blk).withByteBuff(deepCloned).withShared(false).build();
}
}