Temporarily disable caching index/filter blocks

Summary:
Mixing index/filter blocks with data blocks resulted in some known
issues.  To make sure in next release our users won't be affected,
we added a new option in BlockBasedTableFactory::TableOption to
conceal this functionality for now.

This patch also introduced a BlockBasedTableReader::OpenOptions,
which avoids the "infinite" growth of parameters in
BlockBasedTableReader::Open().

Test Plan: make check

Reviewers: haobo, sdong, igor, dhruba

Reviewed By: igor

CC: leveldb, tnovak

Differential Revision: https://reviews.facebook.net/D15327

Author: liukai

db/db_test.cc

@@ -17,6 +17,7 @@
 #include "db/filename.h"
 #include "db/version_set.h"
 #include "db/write_batch_internal.h"
+#include "table/block_based_table_factory.h"
 #include "rocksdb/cache.h"
 #include "rocksdb/compaction_filter.h"
 #include "rocksdb/env.h"
@@ -732,6 +733,9 @@ TEST(DBTest, IndexAndFilterBlocksOfNewTableAddedToCache) {
   options.filter_policy = filter_policy.get();
   options.create_if_missing = true;
   options.statistics = rocksdb::CreateDBStatistics();
+  BlockBasedTableOptions table_options;
+  table_options.cache_index_and_filter_blocks = true;
+  options.table_factory.reset(new BlockBasedTableFactory(table_options));
   DestroyAndReopen(&options);
 
   ASSERT_OK(db_->Put(WriteOptions(), "key", "val"));

table/block_based_table_factory.cc

@@ -20,10 +20,10 @@ namespace rocksdb {
 
 Status BlockBasedTableFactory::GetTableReader(
     const Options& options, const EnvOptions& soptions,
-    unique_ptr<RandomAccessFile> && file, uint64_t file_size,
+    unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
     unique_ptr<TableReader>* table_reader) const {
-  return BlockBasedTable::Open(options, soptions, std::move(file), file_size,
-                               table_reader);
+  return BlockBasedTable::Open(options, soptions, table_options_,
+                               std::move(file), file_size, table_reader);
 }
 
 TableBuilder* BlockBasedTableFactory::GetTableBuilder(

table/block_based_table_factory.h

@@ -14,6 +14,7 @@
 #include "rocksdb/flush_block_policy.h"
 #include "rocksdb/options.h"
 #include "rocksdb/table.h"
+#include "table/block_based_table_options.h"
 
 namespace rocksdb {
 
@@ -30,40 +31,25 @@ class BlockBasedTable;
 class BlockBasedTableBuilder;
 
 class BlockBasedTableFactory: public TableFactory {
-public:
-  struct TableOptions {
-    // @flush_block_policy_factory creates the instances of flush block policy.
-    // which provides a configurable way to determine when to flush a block in
-    // the block based tables.  If not set, table builder will use the default
-    // block flush policy, which cut blocks by block size (please refer to
-    // `FlushBlockBySizePolicy`).
-    std::shared_ptr<FlushBlockPolicyFactory> flush_block_policy_factory;
-  };
+ public:
+  BlockBasedTableFactory() : BlockBasedTableFactory(BlockBasedTableOptions()) {}
+  explicit BlockBasedTableFactory(const BlockBasedTableOptions& table_options)
+      : table_options_(table_options) {}
 
-  BlockBasedTableFactory() : BlockBasedTableFactory(TableOptions()) { }
-  BlockBasedTableFactory(const TableOptions& table_options): 
-      table_options_(table_options) { 
-  }
+  ~BlockBasedTableFactory() {}
 
-  ~BlockBasedTableFactory() {
-  }
-
-  const char* Name() const override {
-    return "BlockBasedTable";
-  }
+  const char* Name() const override { return "BlockBasedTable"; }
 
   Status GetTableReader(const Options& options, const EnvOptions& soptions,
-                        unique_ptr<RandomAccessFile> && file,
-                        uint64_t file_size,
+                        unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
                         unique_ptr<TableReader>* table_reader) const override;
 
   TableBuilder* GetTableBuilder(const Options& options, WritableFile* file,
-                                CompressionType compression_type) const
-                                    override;
+                                CompressionType compression_type)
+      const override;
 
  private:
-  TableOptions table_options_;
+  BlockBasedTableOptions table_options_;
 };
 
-
 }  // namespace rocksdb

table/block_based_table_options.h

@@ -0,0 +1,31 @@
+//  Copyright (c) 2013, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+
+#pragma once
+#include <memory>
+
+namespace rocksdb {
+
+class FlushBlockPolicyFactory;
+
+struct BlockBasedTableOptions {
+  // @flush_block_policy_factory creates the instances of flush block policy.
+  // which provides a configurable way to determine when to flush a block in
+  // the block based tables.  If not set, table builder will use the default
+  // block flush policy, which cut blocks by block size (please refer to
+  // `FlushBlockBySizePolicy`).
+  std::shared_ptr<FlushBlockPolicyFactory> flush_block_policy_factory;
+
+  // TODO(kailiu) Temporarily disable this feature by making the default value
+  // to be false. Also in master branch, this file is non-public so no user
+  // will be able to change the value of `cache_index_and_filter_blocks`.
+  //
+  // Indicating if we'd put index/filter blocks to the block cache.
+  // If not specified, each "table reader" object will pre-load index/filter
+  // block during table initialization.
+  bool cache_index_and_filter_blocks = false;
+};
+
+}  // namespace rocksdb

table/block_based_table_reader.cc

@@ -26,6 +26,7 @@
 #include "util/coding.h"
 #include "util/perf_context_imp.h"
 #include "util/stop_watch.h"
+#include "table/block_based_table_options.h"
 
 namespace rocksdb {
 
@@ -45,9 +46,9 @@ struct BlockBasedTable::Rep {
   Status status;
   unique_ptr<RandomAccessFile> file;
   char cache_key_prefix[kMaxCacheKeyPrefixSize];
-  size_t cache_key_prefix_size;
+  size_t cache_key_prefix_size = 0;
   char compressed_cache_key_prefix[kMaxCacheKeyPrefixSize];
-  size_t compressed_cache_key_prefix_size;
+  size_t compressed_cache_key_prefix_size = 0;
 
   // Handle to metaindex_block: saved from footer
   BlockHandle metaindex_handle;
@@ -220,20 +221,21 @@ Cache::Handle* GetFromBlockCache(
 
 } // end of anonymous namespace
 
-Status BlockBasedTable::Open(const Options& options,
-                             const EnvOptions& soptions,
-                             unique_ptr<RandomAccessFile> && file,
-                             uint64_t size,
+Status BlockBasedTable::Open(const Options& options, const EnvOptions& soptions,
+                             const BlockBasedTableOptions& table_options,
+                             unique_ptr<RandomAccessFile>&& file,
+                             uint64_t file_size,
                              unique_ptr<TableReader>* table_reader) {
   table_reader->reset();
-  if (size < Footer::kEncodedLength) {
+
+  if (file_size < Footer::kEncodedLength) {
     return Status::InvalidArgument("file is too short to be an sstable");
   }
 
   char footer_space[Footer::kEncodedLength];
   Slice footer_input;
-  Status s = file->Read(size - Footer::kEncodedLength, Footer::kEncodedLength,
-                        &footer_input, footer_space);
+  Status s = file->Read(file_size - Footer::kEncodedLength,
+                        Footer::kEncodedLength, &footer_input, footer_space);
   if (!s.ok()) return s;
 
   // Check that we actually read the whole footer from the file. It may be
@@ -277,11 +279,21 @@ Status BlockBasedTable::Open(const Options& options,
     }
   }
 
-  // Initialize index/filter blocks. If block cache is not specified,
-  // these blocks will be kept in member variables in Rep, which will
-  // reside in the memory as long as this table object is alive; otherwise
-  // they will be added to block cache.
-  if (!options.block_cache) {
+  // Will use block cache for index/filter blocks access?
+  if (options.block_cache && table_options.cache_index_and_filter_blocks) {
+    // Call IndexBlockReader() to implicitly add index to the block_cache
+    unique_ptr<Iterator> iter(new_table->IndexBlockReader(ReadOptions()));
+    s = iter->status();
+
+    if (s.ok()) {
+      // Call GetFilter() to implicitly add filter to the block_cache
+      auto filter_entry = new_table->GetFilter();
+      filter_entry.Release(options.block_cache.get());
+    }
+  } else {
+    // If we don't use block cache for index/filter blocks access, we'll
+    // pre-load these blocks, which will kept in member variables in Rep
+    // and with a same life-time as this table object.
     Block* index_block = nullptr;
     // TODO: we never really verify check sum for index block
     s = ReadBlockFromFile(
@@ -309,18 +321,7 @@ Status BlockBasedTable::Open(const Options& options,
     } else {
       delete index_block;
     }
-  } else {
-    // Call IndexBlockReader() to implicitly add index to the block_cache
-    unique_ptr<Iterator> iter(
-        new_table->IndexBlockReader(ReadOptions())
-    );
-    s = iter->status();
 
-    if (s.ok()) {
-      // Call GetFilter() to implicitly add filter to the block_cache
-      auto filter_entry = new_table->GetFilter();
-      filter_entry.Release(options.block_cache.get());
-    }
   }
 
   if (s.ok()) {
@@ -836,7 +837,6 @@ BlockBasedTable::GetFilter(bool no_io) const {
 // Get the iterator from the index block.
 Iterator* BlockBasedTable::IndexBlockReader(const ReadOptions& options) const {
   if (rep_->index_block) {
-    assert (!rep_->options.block_cache);
     return rep_->index_block->NewIterator(rep_->options.comparator);
   }
 

table/block_based_table_reader.h

@@ -29,6 +29,7 @@ struct ReadOptions;
 class TableCache;
 class TableReader;
 class FilterBlockReader;
+struct BlockBasedTableOptions;
 
 using std::unique_ptr;
 
@@ -50,10 +51,9 @@ class BlockBasedTable : public TableReader {
   // to nullptr and returns a non-ok status.
   //
   // *file must remain live while this Table is in use.
-  static Status Open(const Options& options,
-                     const EnvOptions& soptions,
-                     unique_ptr<RandomAccessFile>&& file,
-                     uint64_t file_size,
+  static Status Open(const Options& db_options, const EnvOptions& env_options,
+                     const BlockBasedTableOptions& table_options,
+                     unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
                      unique_ptr<TableReader>* table_reader);
 
   bool PrefixMayMatch(const Slice& internal_prefix) override;

table/table_test.cc

@@ -243,13 +243,12 @@ class BlockConstructor: public Constructor {
 
 class BlockBasedTableConstructor: public Constructor {
  public:
-  explicit BlockBasedTableConstructor(
-      const Comparator* cmp)
-      : Constructor(cmp) {
-  }
+  explicit BlockBasedTableConstructor(const Comparator* cmp)
+      : Constructor(cmp) {}
   ~BlockBasedTableConstructor() {
     Reset();
   }
+
   virtual Status FinishImpl(const Options& options, const KVMap& data) {
     Reset();
     sink_.reset(new StringSink());
@@ -277,7 +276,6 @@ class BlockBasedTableConstructor: public Constructor {
     // Open the table
     uniq_id_ = cur_uniq_id_++;
     source_.reset(new StringSource(sink_->contents(), uniq_id_));
-    unique_ptr<TableFactory> table_factory;
     return options.table_factory->GetTableReader(options, soptions,
                                                  std::move(source_),
                                                  sink_->contents().size(),
@@ -979,6 +977,11 @@ TEST(TableTest, BlockCacheTest) {
   options.create_if_missing = true;
   options.statistics = CreateDBStatistics();
   options.block_cache = NewLRUCache(1024);
+
+  // Enable the cache for index/filter blocks
+  BlockBasedTableOptions table_options;
+  table_options.cache_index_and_filter_blocks = true;
+  options.table_factory.reset(new BlockBasedTableFactory(table_options));
   std::vector<std::string> keys;
   KVMap kvmap;
 
@@ -1292,7 +1295,6 @@ TEST(MemTableTest, Simple) {
   delete memtable->Unref();
 }
 
-
 }  // namespace rocksdb
 
 int main(int argc, char** argv) {