b4ad5e89ae
Summary: Rocksdb can now support a uncompressed block cache, or a compressed block cache or both. Lookups first look for a block in the uncompressed cache, if it is not found only then it is looked up in the compressed cache. If it is found in the compressed cache, then it is uncompressed and inserted into the uncompressed cache. It is possible that the same block resides in the compressed cache as well as the uncompressed cache at the same time. Both caches have their own individual LRU policy. Test Plan: Unit test case attached. Reviewers: kailiu, sdong, haobo, leveldb Reviewed By: haobo CC: xjin, haobo Differential Revision: https://reviews.facebook.net/D12675
760 lines
27 KiB
C++
760 lines
27 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "table/block_based_table_reader.h"
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#include "db/dbformat.h"
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#include "rocksdb/comparator.h"
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#include "rocksdb/env.h"
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#include "rocksdb/filter_policy.h"
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#include "rocksdb/options.h"
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#include "rocksdb/statistics.h"
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#include "rocksdb/table.h"
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#include "table/block.h"
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#include "table/filter_block.h"
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#include "table/format.h"
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#include "table/two_level_iterator.h"
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#include "util/coding.h"
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#include "util/perf_context_imp.h"
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#include "util/stop_watch.h"
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namespace rocksdb {
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// The longest the prefix of the cache key used to identify blocks can be.
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// We are using the fact that we know for Posix files the unique ID is three
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// varints.
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const size_t kMaxCacheKeyPrefixSize = kMaxVarint64Length*3+1;
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struct BlockBasedTable::Rep {
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~Rep() {
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delete filter;
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delete [] filter_data;
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delete index_block;
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}
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Rep(const EnvOptions& storage_options) :
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soptions(storage_options) {
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}
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Options options;
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const EnvOptions& soptions;
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Status status;
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unique_ptr<RandomAccessFile> file;
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char cache_key_prefix[kMaxCacheKeyPrefixSize];
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size_t cache_key_prefix_size;
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char compressed_cache_key_prefix[kMaxCacheKeyPrefixSize];
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size_t compressed_cache_key_prefix_size;
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FilterBlockReader* filter;
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const char* filter_data;
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BlockHandle metaindex_handle; // Handle to metaindex_block: saved from footer
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Block* index_block;
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TableStats table_stats;
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};
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BlockBasedTable::~BlockBasedTable() {
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delete rep_;
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}
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// Helper function to setup the cache key's prefix for the Table.
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void BlockBasedTable::SetupCacheKeyPrefix(Rep* rep) {
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assert(kMaxCacheKeyPrefixSize >= 10);
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rep->cache_key_prefix_size = 0;
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rep->compressed_cache_key_prefix_size = 0;
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if (rep->options.block_cache != nullptr) {
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GenerateCachePrefix(rep->options.block_cache, rep->file.get(),
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&rep->cache_key_prefix[0],
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&rep->cache_key_prefix_size);
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}
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if (rep->options.block_cache_compressed != nullptr) {
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GenerateCachePrefix(rep->options.block_cache_compressed, rep->file.get(),
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&rep->compressed_cache_key_prefix[0],
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&rep->compressed_cache_key_prefix_size);
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}
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}
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void BlockBasedTable::GenerateCachePrefix(shared_ptr<Cache> cc,
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RandomAccessFile* file, char* buffer, size_t* size) {
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// generate an id from the file
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*size = file->GetUniqueId(buffer, kMaxCacheKeyPrefixSize);
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// If the prefix wasn't generated or was too long,
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// create one from the cache.
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if (*size == 0) {
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char* end = EncodeVarint64(buffer, cc->NewId());
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*size = static_cast<size_t>(end - buffer);
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}
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}
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void BlockBasedTable::GenerateCachePrefix(shared_ptr<Cache> cc,
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WritableFile* file, char* buffer, size_t* size) {
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// generate an id from the file
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*size = file->GetUniqueId(buffer, kMaxCacheKeyPrefixSize);
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// If the prefix wasn't generated or was too long,
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// create one from the cache.
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if (*size == 0) {
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char* end = EncodeVarint64(buffer, cc->NewId());
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*size = static_cast<size_t>(end - buffer);
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}
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}
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namespace { // anonymous namespace, not visible externally
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// Read the block identified by "handle" from "file".
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// The only relevant option is options.verify_checksums for now.
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// Set *didIO to true if didIO is not null.
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// On failure return non-OK.
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// On success fill *result and return OK - caller owns *result
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Status ReadBlock(RandomAccessFile* file,
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const ReadOptions& options,
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const BlockHandle& handle,
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Block** result,
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Env* env,
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bool* didIO = nullptr,
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bool do_uncompress = true) {
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BlockContents contents;
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Status s = ReadBlockContents(file, options, handle, &contents,
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env, do_uncompress);
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if (s.ok()) {
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*result = new Block(contents);
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}
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if (didIO) {
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*didIO = true;
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}
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return s;
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}
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} // end of anonymous namespace
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Status BlockBasedTable::Open(const Options& options,
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const EnvOptions& soptions,
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unique_ptr<RandomAccessFile> && file,
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uint64_t size,
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unique_ptr<TableReader>* table_reader) {
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table_reader->reset();
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if (size < Footer::kEncodedLength) {
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return Status::InvalidArgument("file is too short to be an sstable");
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}
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char footer_space[Footer::kEncodedLength];
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Slice footer_input;
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Status s = file->Read(size - Footer::kEncodedLength, Footer::kEncodedLength,
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&footer_input, footer_space);
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if (!s.ok()) return s;
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// Check that we actually read the whole footer from the file. It may be
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// that size isn't correct.
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if (footer_input.size() != Footer::kEncodedLength) {
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return Status::InvalidArgument("file is too short to be an sstable");
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}
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Footer footer;
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s = footer.DecodeFrom(&footer_input);
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if (!s.ok()) return s;
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Block* index_block = nullptr;
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// TODO: we never really verify check sum for index block
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s = ReadBlock(file.get(), ReadOptions(), footer.index_handle(), &index_block,
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options.env);
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if (s.ok()) {
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// We've successfully read the footer and the index block: we're
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// ready to serve requests.
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assert(index_block->compressionType() == kNoCompression);
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BlockBasedTable::Rep* rep = new BlockBasedTable::Rep(soptions);
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rep->options = options;
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rep->file = std::move(file);
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rep->metaindex_handle = footer.metaindex_handle();
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rep->index_block = index_block;
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SetupCacheKeyPrefix(rep);
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rep->filter_data = nullptr;
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rep->filter = nullptr;
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table_reader->reset(new BlockBasedTable(rep));
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((BlockBasedTable*) (table_reader->get()))->ReadMeta(footer);
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} else {
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if (index_block) delete index_block;
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}
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return s;
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}
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void BlockBasedTable::SetupForCompaction() {
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switch (rep_->options.access_hint_on_compaction_start) {
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case Options::NONE:
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break;
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case Options::NORMAL:
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rep_->file->Hint(RandomAccessFile::NORMAL);
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break;
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case Options::SEQUENTIAL:
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rep_->file->Hint(RandomAccessFile::SEQUENTIAL);
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break;
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case Options::WILLNEED:
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rep_->file->Hint(RandomAccessFile::WILLNEED);
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break;
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default:
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assert(false);
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}
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compaction_optimized_ = true;
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}
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TableStats& BlockBasedTable::GetTableStats() {
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return rep_->table_stats;
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}
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void BlockBasedTable::ReadMeta(const Footer& footer) {
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// TODO(sanjay): Skip this if footer.metaindex_handle() size indicates
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// it is an empty block.
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// TODO: we never really verify check sum for meta index block
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Block* meta = nullptr;
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if (!ReadBlock(rep_->file.get(), ReadOptions(), footer.metaindex_handle(),
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&meta, rep_->options.env).ok()) {
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// Do not propagate errors since meta info is not needed for operation
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return;
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}
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assert(meta->compressionType() == kNoCompression);
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Iterator* iter = meta->NewIterator(BytewiseComparator());
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// read filter
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if (rep_->options.filter_policy) {
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std::string key = kFilterBlockPrefix;
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key.append(rep_->options.filter_policy->Name());
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iter->Seek(key);
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if (iter->Valid() && iter->key() == Slice(key)) {
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ReadFilter(iter->value());
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}
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}
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// read stats
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iter->Seek(kStatsBlock);
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if (iter->Valid() && iter->key() == Slice(kStatsBlock)) {
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auto s = iter->status();
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if (s.ok()) {
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s = ReadStats(iter->value(), rep_);
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}
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if (!s.ok()) {
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auto err_msg =
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"[Warning] Encountered error while reading data from stats block " +
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s.ToString();
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Log(rep_->options.info_log, err_msg.c_str());
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}
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}
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delete iter;
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delete meta;
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}
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void BlockBasedTable::ReadFilter(const Slice& filter_handle_value) {
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Slice v = filter_handle_value;
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BlockHandle filter_handle;
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if (!filter_handle.DecodeFrom(&v).ok()) {
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return;
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}
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// TODO: We might want to unify with ReadBlock() if we start
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// requiring checksum verification in BlockBasedTable::Open.
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ReadOptions opt;
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BlockContents block;
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if (!ReadBlockContents(rep_->file.get(), opt, filter_handle, &block,
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rep_->options.env, false).ok()) {
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return;
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}
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if (block.heap_allocated) {
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rep_->filter_data = block.data.data(); // Will need to delete later
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}
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rep_->filter = new FilterBlockReader(rep_->options, block.data);
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}
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Status BlockBasedTable::ReadStats(const Slice& handle_value, Rep* rep) {
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Slice v = handle_value;
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BlockHandle handle;
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if (!handle.DecodeFrom(&v).ok()) {
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return Status::InvalidArgument("Failed to decode stats block handle");
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}
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BlockContents block_contents;
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Status s = ReadBlockContents(
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rep->file.get(),
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ReadOptions(),
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handle,
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&block_contents,
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rep->options.env,
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false
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);
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if (!s.ok()) {
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return s;
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}
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Block stats_block(block_contents);
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std::unique_ptr<Iterator> iter(
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stats_block.NewIterator(BytewiseComparator())
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);
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auto& table_stats = rep->table_stats;
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// All pre-defined stats of type uint64_t
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std::unordered_map<std::string, uint64_t*> predefined_uint64_stats = {
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{ BlockBasedTableStatsNames::kDataSize, &table_stats.data_size },
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{ BlockBasedTableStatsNames::kIndexSize, &table_stats.index_size },
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{ BlockBasedTableStatsNames::kRawKeySize, &table_stats.raw_key_size },
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{ BlockBasedTableStatsNames::kRawValueSize, &table_stats.raw_value_size },
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{ BlockBasedTableStatsNames::kNumDataBlocks, &table_stats.num_data_blocks},
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{ BlockBasedTableStatsNames::kNumEntries, &table_stats.num_entries },
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};
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std::string last_key;
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for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
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s = iter->status();
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if (!s.ok()) {
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break;
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}
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auto key = iter->key().ToString();
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// stats block is strictly sorted with no duplicate key.
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assert(
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last_key.empty() ||
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BytewiseComparator()->Compare(key, last_key) > 0
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);
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last_key = key;
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auto raw_val = iter->value();
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auto pos = predefined_uint64_stats.find(key);
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if (pos != predefined_uint64_stats.end()) {
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// handle predefined rocksdb stats
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uint64_t val;
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if (!GetVarint64(&raw_val, &val)) {
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// skip malformed value
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auto error_msg =
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"[Warning] detect malformed value in stats meta-block:"
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"\tkey: " + key + "\tval: " + raw_val.ToString();
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Log(rep->options.info_log, error_msg.c_str());
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continue;
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}
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*(pos->second) = val;
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} else if (key == BlockBasedTableStatsNames::kFilterPolicy) {
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table_stats.filter_policy_name = raw_val.ToString();
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} else {
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// handle user-collected
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table_stats.user_collected_stats.insert(
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std::make_pair(iter->key().ToString(), raw_val.ToString())
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);
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}
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}
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return s;
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}
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static void DeleteBlock(void* arg, void* ignored) {
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delete reinterpret_cast<Block*>(arg);
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}
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static void DeleteCachedBlock(const Slice& key, void* value) {
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Block* block = reinterpret_cast<Block*>(value);
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delete block;
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}
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static void ReleaseBlock(void* arg, void* h) {
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Cache* cache = reinterpret_cast<Cache*>(arg);
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Cache::Handle* handle = reinterpret_cast<Cache::Handle*>(h);
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cache->Release(handle);
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}
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// Convert an index iterator value (i.e., an encoded BlockHandle)
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// into an iterator over the contents of the corresponding block.
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Iterator* BlockBasedTable::BlockReader(void* arg,
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const ReadOptions& options,
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const Slice& index_value,
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bool* didIO,
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bool for_compaction) {
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const bool no_io = (options.read_tier == kBlockCacheTier);
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BlockBasedTable* table = reinterpret_cast<BlockBasedTable*>(arg);
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Cache* block_cache = table->rep_->options.block_cache.get();
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Cache* block_cache_compressed = table->rep_->options.
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block_cache_compressed.get();
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std::shared_ptr<Statistics> statistics = table->rep_->options.statistics;
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Block* block = nullptr;
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Block* cblock = nullptr;
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Cache::Handle* cache_handle = nullptr;
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Cache::Handle* compressed_cache_handle = nullptr;
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BlockHandle handle;
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Slice input = index_value;
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Status s = handle.DecodeFrom(&input);
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// We intentionally allow extra stuff in index_value so that we
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// can add more features in the future.
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if (s.ok()) {
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if (block_cache != nullptr || block_cache_compressed != nullptr) {
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char cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
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char compressed_cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
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char* end = cache_key;
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// create key for block cache
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if (block_cache != nullptr) {
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assert(table->rep_->cache_key_prefix_size != 0);
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assert(table->rep_->cache_key_prefix_size <= kMaxCacheKeyPrefixSize);
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memcpy(cache_key, table->rep_->cache_key_prefix,
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table->rep_->cache_key_prefix_size);
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end = EncodeVarint64(cache_key + table->rep_->cache_key_prefix_size,
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handle.offset());
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}
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Slice key(cache_key, static_cast<size_t>(end - cache_key));
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// create key for compressed block cache
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end = compressed_cache_key;
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if (block_cache_compressed != nullptr) {
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assert(table->rep_->compressed_cache_key_prefix_size != 0);
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assert(table->rep_->compressed_cache_key_prefix_size <=
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kMaxCacheKeyPrefixSize);
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memcpy(compressed_cache_key, table->rep_->compressed_cache_key_prefix,
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table->rep_->compressed_cache_key_prefix_size);
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end = EncodeVarint64(compressed_cache_key +
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table->rep_->compressed_cache_key_prefix_size,
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handle.offset());
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}
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Slice ckey(compressed_cache_key, static_cast<size_t>
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(end - compressed_cache_key));
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// Lookup uncompressed cache first
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if (block_cache != nullptr) {
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cache_handle = block_cache->Lookup(key);
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if (cache_handle != nullptr) {
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block = reinterpret_cast<Block*>(block_cache->Value(cache_handle));
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RecordTick(statistics, BLOCK_CACHE_HIT);
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}
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}
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// If not found in uncompressed cache, lookup compressed cache
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if (block == nullptr && block_cache_compressed != nullptr) {
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compressed_cache_handle = block_cache_compressed->Lookup(ckey);
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// if we found in the compressed cache, then uncompress and
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// insert into uncompressed cache
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if (compressed_cache_handle != nullptr) {
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// found compressed block
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cblock = reinterpret_cast<Block*>(block_cache_compressed->
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Value(compressed_cache_handle));
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assert(cblock->compressionType() != kNoCompression);
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// Retrieve the uncompressed contents into a new buffer
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BlockContents contents;
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s = UncompressBlockContents(cblock->data(), cblock->size(),
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&contents);
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// Insert uncompressed block into block cache
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if (s.ok()) {
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block = new Block(contents); // uncompressed block
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assert(block->compressionType() == kNoCompression);
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if (block_cache != nullptr && block->isCachable() &&
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options.fill_cache) {
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cache_handle = block_cache->Insert(key, block, block->size(),
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&DeleteCachedBlock);
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assert(reinterpret_cast<Block*>(block_cache->Value(cache_handle))
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== block);
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}
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}
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// Release hold on compressed cache entry
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block_cache_compressed->Release(compressed_cache_handle);
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RecordTick(statistics, BLOCK_CACHE_COMPRESSED_HIT);
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}
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}
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if (block != nullptr) {
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BumpPerfCount(&perf_context.block_cache_hit_count);
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} else if (no_io) {
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// Did not find in block_cache and can't do IO
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return NewErrorIterator(Status::Incomplete("no blocking io"));
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} else {
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Histograms histogram = for_compaction ?
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READ_BLOCK_COMPACTION_MICROS : READ_BLOCK_GET_MICROS;
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{ // block for stop watch
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StopWatch sw(table->rep_->options.env, statistics, histogram);
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s = ReadBlock(
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table->rep_->file.get(),
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options,
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handle,
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&cblock,
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table->rep_->options.env,
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didIO,
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block_cache_compressed == nullptr
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);
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}
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if (s.ok()) {
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assert(cblock->compressionType() == kNoCompression ||
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block_cache_compressed != nullptr);
|
|
|
|
// Retrieve the uncompressed contents into a new buffer
|
|
BlockContents contents;
|
|
if (cblock->compressionType() != kNoCompression) {
|
|
s = UncompressBlockContents(cblock->data(), cblock->size(),
|
|
&contents);
|
|
}
|
|
if (s.ok()) {
|
|
if (cblock->compressionType() != kNoCompression) {
|
|
block = new Block(contents); // uncompressed block
|
|
} else {
|
|
block = cblock;
|
|
cblock = nullptr;
|
|
}
|
|
if (block->isCachable() && options.fill_cache) {
|
|
// Insert compressed block into compressed block cache.
|
|
// Release the hold on the compressed cache entry immediately.
|
|
if (block_cache_compressed != nullptr && cblock != nullptr) {
|
|
compressed_cache_handle = block_cache_compressed->Insert(
|
|
ckey, cblock, cblock->size(), &DeleteCachedBlock);
|
|
block_cache_compressed->Release(compressed_cache_handle);
|
|
RecordTick(statistics, BLOCK_CACHE_COMPRESSED_MISS);
|
|
cblock = nullptr;
|
|
}
|
|
// insert into uncompressed block cache
|
|
assert((block->compressionType() == kNoCompression));
|
|
if (block_cache != nullptr) {
|
|
cache_handle = block_cache->Insert(
|
|
key, block, block->size(), &DeleteCachedBlock);
|
|
RecordTick(statistics, BLOCK_CACHE_MISS);
|
|
assert(reinterpret_cast<Block*>(block_cache->Value(
|
|
cache_handle))== block);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (cblock != nullptr) {
|
|
delete cblock;
|
|
}
|
|
}
|
|
} else if (no_io) {
|
|
// Could not read from block_cache and can't do IO
|
|
return NewErrorIterator(Status::Incomplete("no blocking io"));
|
|
} else {
|
|
s = ReadBlock(table->rep_->file.get(), options, handle, &block,
|
|
table->rep_->options.env, didIO);
|
|
}
|
|
}
|
|
|
|
Iterator* iter;
|
|
if (block != nullptr) {
|
|
iter = block->NewIterator(table->rep_->options.comparator);
|
|
if (cache_handle != nullptr) {
|
|
iter->RegisterCleanup(&ReleaseBlock, block_cache, cache_handle);
|
|
} else {
|
|
iter->RegisterCleanup(&DeleteBlock, block, nullptr);
|
|
}
|
|
} else {
|
|
iter = NewErrorIterator(s);
|
|
}
|
|
return iter;
|
|
}
|
|
|
|
Iterator* BlockBasedTable::BlockReader(void* arg,
|
|
const ReadOptions& options,
|
|
const EnvOptions& soptions,
|
|
const Slice& index_value,
|
|
bool for_compaction) {
|
|
return BlockReader(arg, options, index_value, nullptr, for_compaction);
|
|
}
|
|
|
|
// This will be broken if the user specifies an unusual implementation
|
|
// of Options.comparator, or if the user specifies an unusual
|
|
// definition of prefixes in Options.filter_policy. In particular, we
|
|
// require the following three properties:
|
|
//
|
|
// 1) key.starts_with(prefix(key))
|
|
// 2) Compare(prefix(key), key) <= 0.
|
|
// 3) If Compare(key1, key2) <= 0, then Compare(prefix(key1), prefix(key2)) <= 0
|
|
//
|
|
// TODO(tylerharter): right now, this won't cause I/O since blooms are
|
|
// in memory. When blooms may need to be paged in, we should refactor so that
|
|
// this is only ever called lazily. In particular, this shouldn't be called
|
|
// while the DB lock is held like it is now.
|
|
bool BlockBasedTable::PrefixMayMatch(const Slice& internal_prefix) {
|
|
FilterBlockReader* filter = rep_->filter;
|
|
bool may_match = true;
|
|
Status s;
|
|
|
|
if (filter == nullptr) {
|
|
return true;
|
|
}
|
|
|
|
std::unique_ptr<Iterator> iiter(rep_->index_block->NewIterator(
|
|
rep_->options.comparator));
|
|
iiter->Seek(internal_prefix);
|
|
if (!iiter->Valid()) {
|
|
// we're past end of file
|
|
may_match = false;
|
|
} else if (ExtractUserKey(iiter->key()).starts_with(
|
|
ExtractUserKey(internal_prefix))) {
|
|
// we need to check for this subtle case because our only
|
|
// guarantee is that "the key is a string >= last key in that data
|
|
// block" according to the doc/table_format.txt spec.
|
|
//
|
|
// Suppose iiter->key() starts with the desired prefix; it is not
|
|
// necessarily the case that the corresponding data block will
|
|
// contain the prefix, since iiter->key() need not be in the
|
|
// block. However, the next data block may contain the prefix, so
|
|
// we return true to play it safe.
|
|
may_match = true;
|
|
} else {
|
|
// iiter->key() does NOT start with the desired prefix. Because
|
|
// Seek() finds the first key that is >= the seek target, this
|
|
// means that iiter->key() > prefix. Thus, any data blocks coming
|
|
// after the data block corresponding to iiter->key() cannot
|
|
// possibly contain the key. Thus, the corresponding data block
|
|
// is the only one which could potentially contain the prefix.
|
|
Slice handle_value = iiter->value();
|
|
BlockHandle handle;
|
|
s = handle.DecodeFrom(&handle_value);
|
|
assert(s.ok());
|
|
may_match = filter->PrefixMayMatch(handle.offset(), internal_prefix);
|
|
}
|
|
|
|
RecordTick(rep_->options.statistics, BLOOM_FILTER_PREFIX_CHECKED);
|
|
if (!may_match) {
|
|
RecordTick(rep_->options.statistics, BLOOM_FILTER_PREFIX_USEFUL);
|
|
}
|
|
|
|
return may_match;
|
|
}
|
|
|
|
Iterator* BlockBasedTable::NewIterator(const ReadOptions& options) {
|
|
if (options.prefix) {
|
|
InternalKey internal_prefix(*options.prefix, 0, kTypeValue);
|
|
if (!PrefixMayMatch(internal_prefix.Encode())) {
|
|
// nothing in this file can match the prefix, so we should not
|
|
// bother doing I/O to this file when iterating.
|
|
return NewEmptyIterator();
|
|
}
|
|
}
|
|
|
|
return NewTwoLevelIterator(
|
|
rep_->index_block->NewIterator(rep_->options.comparator),
|
|
&BlockBasedTable::BlockReader, const_cast<BlockBasedTable*>(this),
|
|
options, rep_->soptions);
|
|
}
|
|
|
|
Status BlockBasedTable::Get(
|
|
const ReadOptions& readOptions,
|
|
const Slice& key,
|
|
void* handle_context,
|
|
bool (*result_handler)(void* handle_context, const Slice& k,
|
|
const Slice& v, bool didIO),
|
|
void (*mark_key_may_exist_handler)(void* handle_context)) {
|
|
Status s;
|
|
Iterator* iiter = rep_->index_block->NewIterator(rep_->options.comparator);
|
|
bool done = false;
|
|
for (iiter->Seek(key); iiter->Valid() && !done; iiter->Next()) {
|
|
Slice handle_value = iiter->value();
|
|
FilterBlockReader* filter = rep_->filter;
|
|
BlockHandle handle;
|
|
if (filter != nullptr &&
|
|
handle.DecodeFrom(&handle_value).ok() &&
|
|
!filter->KeyMayMatch(handle.offset(), key)) {
|
|
// Not found
|
|
// TODO: think about interaction with Merge. If a user key cannot
|
|
// cross one data block, we should be fine.
|
|
RecordTick(rep_->options.statistics, BLOOM_FILTER_USEFUL);
|
|
break;
|
|
} else {
|
|
bool didIO = false;
|
|
std::unique_ptr<Iterator> block_iter(
|
|
BlockReader(this, readOptions, iiter->value(), &didIO));
|
|
|
|
if (readOptions.read_tier && block_iter->status().IsIncomplete()) {
|
|
// couldn't get block from block_cache
|
|
// Update Saver.state to Found because we are only looking for whether
|
|
// we can guarantee the key is not there when "no_io" is set
|
|
(*mark_key_may_exist_handler)(handle_context);
|
|
break;
|
|
}
|
|
|
|
// Call the *saver function on each entry/block until it returns false
|
|
for (block_iter->Seek(key); block_iter->Valid(); block_iter->Next()) {
|
|
if (!(*result_handler)(handle_context, block_iter->key(),
|
|
block_iter->value(), didIO)) {
|
|
done = true;
|
|
break;
|
|
}
|
|
}
|
|
s = block_iter->status();
|
|
}
|
|
}
|
|
if (s.ok()) {
|
|
s = iiter->status();
|
|
}
|
|
delete iiter;
|
|
return s;
|
|
}
|
|
|
|
bool SaveDidIO(void* arg, const Slice& key, const Slice& value, bool didIO) {
|
|
*reinterpret_cast<bool*>(arg) = didIO;
|
|
return false;
|
|
}
|
|
bool BlockBasedTable::TEST_KeyInCache(const ReadOptions& options,
|
|
const Slice& key) {
|
|
// We use Get() as it has logic that checks whether we read the
|
|
// block from the disk or not.
|
|
bool didIO = false;
|
|
Status s = Get(options, key, &didIO, SaveDidIO);
|
|
assert(s.ok());
|
|
return !didIO;
|
|
}
|
|
|
|
uint64_t BlockBasedTable::ApproximateOffsetOf(const Slice& key) {
|
|
Iterator* index_iter =
|
|
rep_->index_block->NewIterator(rep_->options.comparator);
|
|
index_iter->Seek(key);
|
|
uint64_t result;
|
|
if (index_iter->Valid()) {
|
|
BlockHandle handle;
|
|
Slice input = index_iter->value();
|
|
Status s = handle.DecodeFrom(&input);
|
|
if (s.ok()) {
|
|
result = handle.offset();
|
|
} else {
|
|
// Strange: we can't decode the block handle in the index block.
|
|
// We'll just return the offset of the metaindex block, which is
|
|
// close to the whole file size for this case.
|
|
result = rep_->metaindex_handle.offset();
|
|
}
|
|
} else {
|
|
// key is past the last key in the file. Approximate the offset
|
|
// by returning the offset of the metaindex block (which is
|
|
// right near the end of the file).
|
|
result = rep_->metaindex_handle.offset();
|
|
}
|
|
delete index_iter;
|
|
return result;
|
|
}
|
|
|
|
const std::string BlockBasedTable::kFilterBlockPrefix = "filter.";
|
|
const std::string BlockBasedTable::kStatsBlock = "rocksdb.stats";
|
|
|
|
const std::string BlockBasedTableStatsNames::kDataSize = "rocksdb.data.size";
|
|
const std::string BlockBasedTableStatsNames::kIndexSize = "rocksdb.index.size";
|
|
const std::string BlockBasedTableStatsNames::kRawKeySize =
|
|
"rocksdb.raw.key.size";
|
|
const std::string BlockBasedTableStatsNames::kRawValueSize =
|
|
"rocksdb.raw.value.size";
|
|
const std::string BlockBasedTableStatsNames::kNumDataBlocks =
|
|
"rocksdb.num.data.blocks";
|
|
const std::string BlockBasedTableStatsNames::kNumEntries =
|
|
"rocksdb.num.entries";
|
|
const std::string BlockBasedTableStatsNames::kFilterPolicy =
|
|
"rocksdb.filter.policy";
|
|
|
|
} // namespace rocksdb
|