rocksdb/table/meta_blocks.cc
Siying Dong 666a005f9b Support prefetch last 512KB with direct I/O in block based file reader
Summary:
Right now, if direct I/O is enabled, prefetching the last 512KB cannot be applied, except compaction inputs or readahead is enabled for iterators. This can create a lot of I/O for HDD cases. To solve the problem, the 512KB is prefetched in block based table if direct I/O is enabled. The prefetched buffer is passed in totegher with random access file reader, so that we try to read from the buffer before reading from the file. This can be extended in the future to support flexible user iterator readahead too.
Closes https://github.com/facebook/rocksdb/pull/2708

Differential Revision: D5593091

Pulled By: siying

fbshipit-source-id: ee36ff6d8af11c312a2622272b21957a7b5c81e7
2017-08-11 12:16:45 -07:00

412 lines
14 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "table/meta_blocks.h"
#include <map>
#include <string>
#include "db/table_properties_collector.h"
#include "rocksdb/table.h"
#include "rocksdb/table_properties.h"
#include "table/block.h"
#include "table/format.h"
#include "table/internal_iterator.h"
#include "table/persistent_cache_helper.h"
#include "table/table_properties_internal.h"
#include "util/coding.h"
#include "util/file_reader_writer.h"
namespace rocksdb {
MetaIndexBuilder::MetaIndexBuilder()
: meta_index_block_(new BlockBuilder(1 /* restart interval */)) {}
void MetaIndexBuilder::Add(const std::string& key,
const BlockHandle& handle) {
std::string handle_encoding;
handle.EncodeTo(&handle_encoding);
meta_block_handles_.insert({key, handle_encoding});
}
Slice MetaIndexBuilder::Finish() {
for (const auto& metablock : meta_block_handles_) {
meta_index_block_->Add(metablock.first, metablock.second);
}
return meta_index_block_->Finish();
}
PropertyBlockBuilder::PropertyBlockBuilder()
: properties_block_(new BlockBuilder(1 /* restart interval */)) {}
void PropertyBlockBuilder::Add(const std::string& name,
const std::string& val) {
props_.insert({name, val});
}
void PropertyBlockBuilder::Add(const std::string& name, uint64_t val) {
assert(props_.find(name) == props_.end());
std::string dst;
PutVarint64(&dst, val);
Add(name, dst);
}
void PropertyBlockBuilder::Add(
const UserCollectedProperties& user_collected_properties) {
for (const auto& prop : user_collected_properties) {
Add(prop.first, prop.second);
}
}
void PropertyBlockBuilder::AddTableProperty(const TableProperties& props) {
Add(TablePropertiesNames::kRawKeySize, props.raw_key_size);
Add(TablePropertiesNames::kRawValueSize, props.raw_value_size);
Add(TablePropertiesNames::kDataSize, props.data_size);
Add(TablePropertiesNames::kIndexSize, props.index_size);
if (props.index_partitions != 0) {
Add(TablePropertiesNames::kIndexPartitions, props.index_partitions);
Add(TablePropertiesNames::kTopLevelIndexSize, props.top_level_index_size);
}
Add(TablePropertiesNames::kNumEntries, props.num_entries);
Add(TablePropertiesNames::kNumDataBlocks, props.num_data_blocks);
Add(TablePropertiesNames::kFilterSize, props.filter_size);
Add(TablePropertiesNames::kFormatVersion, props.format_version);
Add(TablePropertiesNames::kFixedKeyLen, props.fixed_key_len);
Add(TablePropertiesNames::kColumnFamilyId, props.column_family_id);
Add(TablePropertiesNames::kCreationTime, props.creation_time);
if (!props.filter_policy_name.empty()) {
Add(TablePropertiesNames::kFilterPolicy, props.filter_policy_name);
}
if (!props.comparator_name.empty()) {
Add(TablePropertiesNames::kComparator, props.comparator_name);
}
if (!props.merge_operator_name.empty()) {
Add(TablePropertiesNames::kMergeOperator, props.merge_operator_name);
}
if (!props.prefix_extractor_name.empty()) {
Add(TablePropertiesNames::kPrefixExtractorName,
props.prefix_extractor_name);
}
if (!props.property_collectors_names.empty()) {
Add(TablePropertiesNames::kPropertyCollectors,
props.property_collectors_names);
}
if (!props.column_family_name.empty()) {
Add(TablePropertiesNames::kColumnFamilyName, props.column_family_name);
}
if (!props.compression_name.empty()) {
Add(TablePropertiesNames::kCompression, props.compression_name);
}
}
Slice PropertyBlockBuilder::Finish() {
for (const auto& prop : props_) {
properties_block_->Add(prop.first, prop.second);
}
return properties_block_->Finish();
}
void LogPropertiesCollectionError(
Logger* info_log, const std::string& method, const std::string& name) {
assert(method == "Add" || method == "Finish");
std::string msg =
"Encountered error when calling TablePropertiesCollector::" +
method + "() with collector name: " + name;
ROCKS_LOG_ERROR(info_log, "%s", msg.c_str());
}
bool NotifyCollectTableCollectorsOnAdd(
const Slice& key, const Slice& value, uint64_t file_size,
const std::vector<std::unique_ptr<IntTblPropCollector>>& collectors,
Logger* info_log) {
bool all_succeeded = true;
for (auto& collector : collectors) {
Status s = collector->InternalAdd(key, value, file_size);
all_succeeded = all_succeeded && s.ok();
if (!s.ok()) {
LogPropertiesCollectionError(info_log, "Add" /* method */,
collector->Name());
}
}
return all_succeeded;
}
bool NotifyCollectTableCollectorsOnFinish(
const std::vector<std::unique_ptr<IntTblPropCollector>>& collectors,
Logger* info_log, PropertyBlockBuilder* builder) {
bool all_succeeded = true;
for (auto& collector : collectors) {
UserCollectedProperties user_collected_properties;
Status s = collector->Finish(&user_collected_properties);
all_succeeded = all_succeeded && s.ok();
if (!s.ok()) {
LogPropertiesCollectionError(info_log, "Finish" /* method */,
collector->Name());
} else {
builder->Add(user_collected_properties);
}
}
return all_succeeded;
}
Status ReadProperties(const Slice& handle_value, RandomAccessFileReader* file,
FilePrefetchBuffer* prefetch_buffer, const Footer& footer,
const ImmutableCFOptions& ioptions,
TableProperties** table_properties) {
assert(table_properties);
Slice v = handle_value;
BlockHandle handle;
if (!handle.DecodeFrom(&v).ok()) {
return Status::InvalidArgument("Failed to decode properties block handle");
}
BlockContents block_contents;
ReadOptions read_options;
read_options.verify_checksums = false;
Status s;
s = ReadBlockContents(file, prefetch_buffer, footer, read_options, handle,
&block_contents, ioptions, false /* decompress */);
if (!s.ok()) {
return s;
}
Block properties_block(std::move(block_contents),
kDisableGlobalSequenceNumber);
BlockIter iter;
properties_block.NewIterator(BytewiseComparator(), &iter);
auto new_table_properties = new TableProperties();
// All pre-defined properties of type uint64_t
std::unordered_map<std::string, uint64_t*> predefined_uint64_properties = {
{TablePropertiesNames::kDataSize, &new_table_properties->data_size},
{TablePropertiesNames::kIndexSize, &new_table_properties->index_size},
{TablePropertiesNames::kIndexPartitions,
&new_table_properties->index_partitions},
{TablePropertiesNames::kTopLevelIndexSize,
&new_table_properties->top_level_index_size},
{TablePropertiesNames::kFilterSize, &new_table_properties->filter_size},
{TablePropertiesNames::kRawKeySize, &new_table_properties->raw_key_size},
{TablePropertiesNames::kRawValueSize,
&new_table_properties->raw_value_size},
{TablePropertiesNames::kNumDataBlocks,
&new_table_properties->num_data_blocks},
{TablePropertiesNames::kNumEntries, &new_table_properties->num_entries},
{TablePropertiesNames::kFormatVersion,
&new_table_properties->format_version},
{TablePropertiesNames::kFixedKeyLen,
&new_table_properties->fixed_key_len},
{TablePropertiesNames::kColumnFamilyId,
&new_table_properties->column_family_id},
{TablePropertiesNames::kCreationTime,
&new_table_properties->creation_time},
};
std::string last_key;
for (iter.SeekToFirst(); iter.Valid(); iter.Next()) {
s = iter.status();
if (!s.ok()) {
break;
}
auto key = iter.key().ToString();
// properties block is strictly sorted with no duplicate key.
assert(last_key.empty() ||
BytewiseComparator()->Compare(key, last_key) > 0);
last_key = key;
auto raw_val = iter.value();
auto pos = predefined_uint64_properties.find(key);
new_table_properties->properties_offsets.insert(
{key, handle.offset() + iter.ValueOffset()});
if (pos != predefined_uint64_properties.end()) {
// handle predefined rocksdb properties
uint64_t val;
if (!GetVarint64(&raw_val, &val)) {
// skip malformed value
auto error_msg =
"Detect malformed value in properties meta-block:"
"\tkey: " + key + "\tval: " + raw_val.ToString();
ROCKS_LOG_ERROR(ioptions.info_log, "%s", error_msg.c_str());
continue;
}
*(pos->second) = val;
} else if (key == TablePropertiesNames::kFilterPolicy) {
new_table_properties->filter_policy_name = raw_val.ToString();
} else if (key == TablePropertiesNames::kColumnFamilyName) {
new_table_properties->column_family_name = raw_val.ToString();
} else if (key == TablePropertiesNames::kComparator) {
new_table_properties->comparator_name = raw_val.ToString();
} else if (key == TablePropertiesNames::kMergeOperator) {
new_table_properties->merge_operator_name = raw_val.ToString();
} else if (key == TablePropertiesNames::kPrefixExtractorName) {
new_table_properties->prefix_extractor_name = raw_val.ToString();
} else if (key == TablePropertiesNames::kPropertyCollectors) {
new_table_properties->property_collectors_names = raw_val.ToString();
} else if (key == TablePropertiesNames::kCompression) {
new_table_properties->compression_name = raw_val.ToString();
} else {
// handle user-collected properties
new_table_properties->user_collected_properties.insert(
{key, raw_val.ToString()});
}
}
if (s.ok()) {
*table_properties = new_table_properties;
} else {
delete new_table_properties;
}
return s;
}
Status ReadTableProperties(RandomAccessFileReader* file, uint64_t file_size,
uint64_t table_magic_number,
const ImmutableCFOptions &ioptions,
TableProperties** properties) {
// -- Read metaindex block
Footer footer;
auto s = ReadFooterFromFile(file, nullptr /* prefetch_buffer */, file_size,
&footer, table_magic_number);
if (!s.ok()) {
return s;
}
auto metaindex_handle = footer.metaindex_handle();
BlockContents metaindex_contents;
ReadOptions read_options;
read_options.verify_checksums = false;
s = ReadBlockContents(file, nullptr /* prefetch_buffer */, footer,
read_options, metaindex_handle, &metaindex_contents,
ioptions, false /* decompress */);
if (!s.ok()) {
return s;
}
Block metaindex_block(std::move(metaindex_contents),
kDisableGlobalSequenceNumber);
std::unique_ptr<InternalIterator> meta_iter(
metaindex_block.NewIterator(BytewiseComparator()));
// -- Read property block
bool found_properties_block = true;
s = SeekToPropertiesBlock(meta_iter.get(), &found_properties_block);
if (!s.ok()) {
return s;
}
TableProperties table_properties;
if (found_properties_block == true) {
s = ReadProperties(meta_iter->value(), file, nullptr /* prefetch_buffer */,
footer, ioptions, properties);
} else {
s = Status::NotFound();
}
return s;
}
Status FindMetaBlock(InternalIterator* meta_index_iter,
const std::string& meta_block_name,
BlockHandle* block_handle) {
meta_index_iter->Seek(meta_block_name);
if (meta_index_iter->status().ok() && meta_index_iter->Valid() &&
meta_index_iter->key() == meta_block_name) {
Slice v = meta_index_iter->value();
return block_handle->DecodeFrom(&v);
} else {
return Status::Corruption("Cannot find the meta block", meta_block_name);
}
}
Status FindMetaBlock(RandomAccessFileReader* file, uint64_t file_size,
uint64_t table_magic_number,
const ImmutableCFOptions &ioptions,
const std::string& meta_block_name,
BlockHandle* block_handle) {
Footer footer;
auto s = ReadFooterFromFile(file, nullptr /* prefetch_buffer */, file_size,
&footer, table_magic_number);
if (!s.ok()) {
return s;
}
auto metaindex_handle = footer.metaindex_handle();
BlockContents metaindex_contents;
ReadOptions read_options;
read_options.verify_checksums = false;
s = ReadBlockContents(file, nullptr /* prefetch_buffer */, footer,
read_options, metaindex_handle, &metaindex_contents,
ioptions, false /* do decompression */);
if (!s.ok()) {
return s;
}
Block metaindex_block(std::move(metaindex_contents),
kDisableGlobalSequenceNumber);
std::unique_ptr<InternalIterator> meta_iter;
meta_iter.reset(metaindex_block.NewIterator(BytewiseComparator()));
return FindMetaBlock(meta_iter.get(), meta_block_name, block_handle);
}
Status ReadMetaBlock(RandomAccessFileReader* file,
FilePrefetchBuffer* prefetch_buffer, uint64_t file_size,
uint64_t table_magic_number,
const ImmutableCFOptions& ioptions,
const std::string& meta_block_name,
BlockContents* contents) {
Status status;
Footer footer;
status = ReadFooterFromFile(file, prefetch_buffer, file_size, &footer,
table_magic_number);
if (!status.ok()) {
return status;
}
// Reading metaindex block
auto metaindex_handle = footer.metaindex_handle();
BlockContents metaindex_contents;
ReadOptions read_options;
read_options.verify_checksums = false;
status = ReadBlockContents(file, prefetch_buffer, footer, read_options,
metaindex_handle, &metaindex_contents, ioptions,
false /* decompress */);
if (!status.ok()) {
return status;
}
// Finding metablock
Block metaindex_block(std::move(metaindex_contents),
kDisableGlobalSequenceNumber);
std::unique_ptr<InternalIterator> meta_iter;
meta_iter.reset(metaindex_block.NewIterator(BytewiseComparator()));
BlockHandle block_handle;
status = FindMetaBlock(meta_iter.get(), meta_block_name, &block_handle);
if (!status.ok()) {
return status;
}
// Reading metablock
return ReadBlockContents(file, prefetch_buffer, footer, read_options,
block_handle, contents, ioptions,
false /* decompress */);
}
} // namespace rocksdb