[RocksDB] [Performance Branch] Some Changes to PlainTable format

Summary:
Some changes to PlainTable format:
(1) support variable key length
(2) use user defined slice transformer to extract prefixes
(3) Run some test cases against PlainTable in db_test and table_test

Test Plan: test db_test

Reviewers: haobo, kailiu

CC: dhruba, igor, leveldb, nkg-

Differential Revision: https://reviews.facebook.net/D14457
This commit is contained in:
Siying Dong 2013-12-20 09:35:24 -08:00
parent 28c24de8be
commit abaf26266d
15 changed files with 736 additions and 378 deletions

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@ -23,6 +23,7 @@
#include "rocksdb/env.h"
#include "rocksdb/table.h"
#include "rocksdb/perf_context.h"
#include "rocksdb/plain_table_factory.h"
#include "util/hash.h"
#include "util/logging.h"
#include "util/mutexlock.h"
@ -244,6 +245,8 @@ class DBTest {
// Sequence of option configurations to try
enum OptionConfig {
kDefault,
kPlainTableFirstBytePrefix,
kPlainTableAllBytesPrefix,
kVectorRep,
kMergePut,
kFilter,
@ -275,7 +278,8 @@ class DBTest {
kNoSkip = 0,
kSkipDeletesFilterFirst = 1,
kSkipUniversalCompaction = 2,
kSkipMergePut = 4
kSkipMergePut = 4,
kSkipPlainTable = 8
};
DBTest() : option_config_(kDefault),
@ -297,20 +301,27 @@ class DBTest {
// Switch to a fresh database with the next option configuration to
// test. Return false if there are no more configurations to test.
bool ChangeOptions(int skip_mask = kNoSkip) {
option_config_++;
// skip some options
if (skip_mask & kSkipDeletesFilterFirst &&
option_config_ == kDeletesFilterFirst) {
option_config_++;
}
if (skip_mask & kSkipUniversalCompaction &&
option_config_ == kUniversalCompaction) {
option_config_++;
}
if (skip_mask & kSkipMergePut && option_config_ == kMergePut) {
option_config_++;
for(option_config_++; option_config_ < kEnd; option_config_++) {
if ((skip_mask & kSkipDeletesFilterFirst) &&
option_config_ == kDeletesFilterFirst) {
continue;
}
if ((skip_mask & kSkipUniversalCompaction) &&
option_config_ == kUniversalCompaction) {
continue;
}
if ((skip_mask & kSkipMergePut) && option_config_ == kMergePut) {
continue;
}
if ((skip_mask & kSkipPlainTable)
&& (option_config_ == kPlainTableAllBytesPrefix
|| option_config_ == kPlainTableFirstBytePrefix)) {
continue;
}
break;
}
if (option_config_ >= kEnd) {
Destroy(&last_options_);
return false;
@ -343,6 +354,18 @@ class DBTest {
options.memtable_factory.reset(
NewHashSkipListRepFactory(NewFixedPrefixTransform(1)));
break;
case kPlainTableFirstBytePrefix:
options.table_factory.reset(new PlainTableFactory());
options.prefix_extractor = NewFixedPrefixTransform(1);
options.allow_mmap_reads = true;
options.max_sequential_skip_in_iterations = 999999;
break;
case kPlainTableAllBytesPrefix:
options.table_factory.reset(new PlainTableFactory());
options.prefix_extractor = NewNoopTransform();
options.allow_mmap_reads = true;
options.max_sequential_skip_in_iterations = 999999;
break;
case kMergePut:
options.merge_operator = MergeOperators::CreatePutOperator();
break;
@ -1009,7 +1032,10 @@ TEST(DBTest, KeyMayExist) {
options.statistics.get()->getTickerCount(BLOCK_CACHE_ADD));
delete options.filter_policy;
} while (ChangeOptions());
// KeyMayExist function only checks data in block caches, which is not used
// by plain table format.
} while (ChangeOptions(kSkipPlainTable));
}
TEST(DBTest, NonBlockingIteration) {
@ -1073,7 +1099,9 @@ TEST(DBTest, NonBlockingIteration) {
options.statistics.get()->getTickerCount(BLOCK_CACHE_ADD));
delete iter;
} while (ChangeOptions());
// This test verifies block cache behaviors, which is not used by plain
// table format.
} while (ChangeOptions(kSkipPlainTable));
}
// A delete is skipped for key if KeyMayExist(key) returns False
@ -2932,7 +2960,8 @@ TEST(DBTest, ApproximateSizes) {
ASSERT_EQ(NumTableFilesAtLevel(0), 0);
ASSERT_GT(NumTableFilesAtLevel(1), 0);
}
} while (ChangeOptions(kSkipUniversalCompaction));
// ApproximateOffsetOf() is not yet implemented in plain table format.
} while (ChangeOptions(kSkipUniversalCompaction | kSkipPlainTable));
}
TEST(DBTest, ApproximateSizes_MixOfSmallAndLarge) {
@ -2970,7 +2999,8 @@ TEST(DBTest, ApproximateSizes_MixOfSmallAndLarge) {
dbfull()->TEST_CompactRange(0, nullptr, nullptr);
}
} while (ChangeOptions());
// ApproximateOffsetOf() is not yet implemented in plain table format.
} while (ChangeOptions(kSkipPlainTable));
}
TEST(DBTest, IteratorPinsRef) {
@ -3054,7 +3084,9 @@ TEST(DBTest, HiddenValuesAreRemoved) {
ASSERT_EQ(AllEntriesFor("foo"), "[ tiny ]");
ASSERT_TRUE(Between(Size("", "pastfoo"), 0, 1000));
} while (ChangeOptions(kSkipUniversalCompaction));
// ApproximateOffsetOf() is not yet implemented in plain table format,
// which is used by Size().
} while (ChangeOptions(kSkipUniversalCompaction | kSkipPlainTable));
}
TEST(DBTest, CompactBetweenSnapshots) {
@ -4626,7 +4658,8 @@ TEST(DBTest, Randomized) {
// TODO(sanjay): Test Get() works
int p = rnd.Uniform(100);
int minimum = 0;
if (option_config_ == kHashSkipList) {
if (option_config_ == kHashSkipList ||
option_config_ == kPlainTableFirstBytePrefix) {
minimum = 1;
}
if (p < 45) { // Put

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@ -59,7 +59,8 @@ public:
// Return the current option configuration.
Options CurrentOptions() {
Options options;
options.table_factory.reset(new PlainTableFactory(16, 8, 2, 0.8));
options.table_factory.reset(new PlainTableFactory(16, 2, 0.8));
options.prefix_extractor = NewFixedPrefixTransform(8);
options.allow_mmap_reads = true;
return options;
}

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@ -23,41 +23,37 @@ class TableBuilder;
// IndexedTable requires fixed length key, configured as a constructor
// parameter of the factory class. Output file format:
// +-------------+
// | version |
// +-------------+------------------------------+ <= key1 offset
// | key1 | value_size (4 bytes) | |
// +----------------------------------------+ |
// +-------------+-----------------+
// | version | user_key_length |
// +------------++------------------------------+ <= key1 offset
// | [key_size] | key1 | value_size | |
// +------------+-------------+-------------+ |
// | value1 |
// | |
// +----------------------------------------+---+ <= key2 offset
// | key2 | value_size (4 bytes) | |
// +----------------------------------------+ |
// | [key_size] | key2 | value_size | |
// +------------+-------------+-------------+ |
// | value2 |
// | |
// | ...... |
// +-----------------+--------------------------+ <= index_block_offset
// | key1 | key1 offset (8 bytes) |
// +-----------------+--------------------------+
// | key2 | key2 offset (8 bytes) |
// +-----------------+--------------------------+
// | key3 | key3 offset (8 bytes) |
// +-----------------+--------------------------+
// | ...... |
// +-----------------+------------+-------------+
// If user_key_length = kVariableLength, it means the key is variable length,
// there will be an extra field for key size encoded before every key.
class PlainTableFactory: public TableFactory {
public:
~PlainTableFactory() {
}
// user_key_size is the length of the user key. key_prefix_len is the
// length of the prefix used for in-memory indexes. bloom_num_bits is
// user_key_size is the length of the user key. If it is set to be
// kVariableLength, then it means variable length. Otherwise, all the
// keys need to have the fix length of this value. bloom_num_bits is
// number of bits used for bloom filer per key. hash_table_ratio is
// the desired ultilization of the hash table used for prefix hashing.
// the desired utilization of the hash table used for prefix hashing.
// hash_table_ratio = number of prefixes / #buckets in the hash table
PlainTableFactory(int user_key_size, int key_prefix_len,
int bloom_num_bits = 0, double hash_table_ratio = 0.75) :
user_key_size_(user_key_size), key_prefix_len_(key_prefix_len),
bloom_num_bits_(bloom_num_bits), hash_table_ratio_(hash_table_ratio) {
explicit PlainTableFactory(uint32_t user_key_len = kVariableLength,
int bloom_num_bits = 0,
double hash_table_ratio = 0.75) :
user_key_len_(user_key_len), bloom_num_bits_(bloom_num_bits),
hash_table_ratio_(hash_table_ratio) {
}
const char* Name() const override {
return "PlainTable";
@ -70,9 +66,10 @@ public:
TableBuilder* GetTableBuilder(const Options& options, WritableFile* file,
CompressionType compression_type) const
override;
static const uint32_t kVariableLength = 0;
private:
int user_key_size_;
int key_prefix_len_;
uint32_t user_key_len_;
int bloom_num_bits_;
double hash_table_ratio_;
};

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@ -37,6 +37,10 @@ struct TableProperties {
uint64_t num_data_blocks = 0;
// the number of entries in this table
uint64_t num_entries = 0;
// format version, reserved for backward compatibility
uint64_t format_version = 0;
// If 0, key is variable length. Otherwise number of bytes for each key.
uint64_t fixed_key_len = 0;
// The name of the filter policy used in this table.
// If no filter policy is used, `filter_policy_name` will be an empty string.
@ -61,6 +65,8 @@ struct TablePropertiesNames {
static const std::string kRawValueSize;
static const std::string kNumDataBlocks;
static const std::string kNumEntries;
static const std::string kFormatVersion;
static const std::string kFixedKeyLen;
static const std::string kFilterPolicy;
};

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@ -67,6 +67,8 @@ void PropertyBlockBuilder::AddTableProperty(const TableProperties& props) {
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);
if (!props.filter_policy_name.empty()) {
Add(TablePropertiesNames::kFilterPolicy,
@ -175,6 +177,8 @@ Status ReadProperties(
{ TablePropertiesNames::kNumDataBlocks,
&table_properties->num_data_blocks },
{ TablePropertiesNames::kNumEntries, &table_properties->num_entries },
{ TablePropertiesNames::kFormatVersion, &table_properties->format_version },
{ TablePropertiesNames::kFixedKeyLen, &table_properties->fixed_key_len },
};
std::string last_key;

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@ -50,12 +50,9 @@ extern const uint64_t kPlainTableMagicNumber = 0x4f3418eb7a8f13b8ull;
PlainTableBuilder::PlainTableBuilder(const Options& options,
WritableFile* file,
int user_key_size, int key_prefix_len) :
options_(options), file_(file), user_key_size_(user_key_size) {
std::string version;
PutFixed32(&version, 1 | 0x80000000);
file_->Append(Slice(version));
offset_ = 4;
uint32_t user_key_len) :
options_(options), file_(file), user_key_len_(user_key_len) {
properties_.fixed_key_len = user_key_len;
// for plain table, we put all the data in a big chuck.
properties_.num_data_blocks = 1;
@ -63,25 +60,37 @@ PlainTableBuilder::PlainTableBuilder(const Options& options,
// filter block.
properties_.index_size = 0;
properties_.filter_size = 0;
properties_.format_version = 0;
}
PlainTableBuilder::~PlainTableBuilder() {
}
void PlainTableBuilder::Add(const Slice& key, const Slice& value) {
assert((int) key.size() == GetInternalKeyLength());
assert(user_key_len_ == 0 || key.size() == user_key_len_ + 8);
// Write key-value pair
if (!IsFixedLength()) {
// Write key length
int key_size = key.size();
key_size_str_.clear();
PutVarint32(&key_size_str_, key_size);
file_->Append(key_size_str_);
offset_ += key_size_str_.length();
}
// Write key
file_->Append(key);
offset_ += GetInternalKeyLength();
offset_ += key.size();
std::string size;
// Write value length
value_size_str_.clear();
int value_size = value.size();
PutVarint32(&size, value_size);
Slice sizeSlice(size);
file_->Append(sizeSlice);
PutVarint32(&value_size_str_, value_size);
file_->Append(value_size_str_);
// Write value
file_->Append(value);
offset_ += value_size + size.length();
offset_ += value_size + value_size_str_.length();
properties_.num_entries++;
properties_.raw_key_size += key.size();

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@ -27,7 +27,7 @@ public:
// will be part of level specified by 'level'. A value of -1 means
// that the caller does not know which level the output file will reside.
PlainTableBuilder(const Options& options, WritableFile* file,
int user_key_size, int key_prefix_len);
uint32_t user_key_size);
// REQUIRES: Either Finish() or Abandon() has been called.
~PlainTableBuilder();
@ -66,11 +66,14 @@ private:
Status status_;
TableProperties properties_;
const size_t user_key_size_;
const size_t user_key_len_;
bool closed_ = false; // Either Finish() or Abandon() has been called.
int GetInternalKeyLength() {
return user_key_size_ + 8;
std::string key_size_str_;
std::string value_size_str_;
bool IsFixedLength() const {
return user_key_len_ > 0;
}
// No copying allowed

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@ -19,13 +19,12 @@ Status PlainTableFactory::GetTableReader(const Options& options,
unique_ptr<TableReader>* table)
const {
return PlainTableReader::Open(options, soptions, std::move(file), file_size,
table, user_key_size_, key_prefix_len_,
bloom_num_bits_, hash_table_ratio_);
table, bloom_num_bits_, hash_table_ratio_);
}
TableBuilder* PlainTableFactory::GetTableBuilder(
const Options& options, WritableFile* file,
CompressionType compression_type) const {
return new PlainTableBuilder(options, file, user_key_size_, key_prefix_len_);
return new PlainTableBuilder(options, file, user_key_len_);
}
} // namespace rocksdb

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@ -15,6 +15,7 @@
#include "rocksdb/filter_policy.h"
#include "rocksdb/options.h"
#include "rocksdb/statistics.h"
#include "rocksdb/plain_table_factory.h"
#include "table/block.h"
#include "table/filter_block.h"
@ -23,6 +24,7 @@
#include "table/two_level_iterator.h"
#include "util/coding.h"
#include "util/dynamic_bloom.h"
#include "util/hash.h"
#include "util/histogram.h"
#include "util/murmurhash.h"
@ -30,46 +32,36 @@
#include "util/stop_watch.h"
namespace std {
template<>
struct hash<rocksdb::Slice> {
public:
std::size_t operator()(rocksdb::Slice const& s) const {
return MurmurHash(s.data(), s.size(), 397);
}
};
}
namespace rocksdb {
extern const uint64_t kPlainTableMagicNumber;
static uint32_t getBucketId(Slice const& s, size_t prefix_len,
uint32_t num_buckets) {
return MurmurHash(s.data(), prefix_len, 397) % num_buckets;
static uint32_t GetSliceHash(Slice const& s) {
return Hash(s.data(), s.size(), 397) ;
}
static uint32_t getBucketIdFromHash(uint32_t hash, uint32_t num_buckets) {
return hash % num_buckets;
}
PlainTableReader::PlainTableReader(const EnvOptions& storage_options,
uint64_t file_size, int user_key_size,
int key_prefix_len, int bloom_bits_per_key,
uint64_t file_size, int bloom_bits_per_key,
double hash_table_ratio,
const TableProperties& table_properties) :
hash_table_size_(0), soptions_(storage_options), file_size_(file_size),
user_key_size_(user_key_size), key_prefix_len_(key_prefix_len),
hash_table_ratio_(hash_table_ratio),
filter_policy_(bloom_bits_per_key > 0 ?
NewBloomFilterPolicy(bloom_bits_per_key) : nullptr),
table_properties_(table_properties),
data_start_offset_(0),
data_end_offset_(table_properties_.data_size) {
bloom_bits_per_key_(bloom_bits_per_key),
table_properties_(table_properties), data_start_offset_(0),
data_end_offset_(table_properties_.data_size),
user_key_len_(table_properties.fixed_key_len) {
hash_table_ = nullptr;
bloom_ = nullptr;
sub_index_ = nullptr;
}
PlainTableReader::~PlainTableReader() {
if (hash_table_ != nullptr) {
delete[] hash_table_;
}
if (filter_policy_ != nullptr) {
delete filter_policy_;
}
delete[] hash_table_;
delete[] sub_index_;
delete bloom_;
}
Status PlainTableReader::Open(const Options& options,
@ -77,8 +69,6 @@ Status PlainTableReader::Open(const Options& options,
unique_ptr<RandomAccessFile> && file,
uint64_t file_size,
unique_ptr<TableReader>* table_reader,
const int user_key_size,
const int key_prefix_len,
const int bloom_num_bits,
double hash_table_ratio) {
assert(options.allow_mmap_reads);
@ -103,8 +93,6 @@ Status PlainTableReader::Open(const Options& options,
std::unique_ptr<PlainTableReader> new_reader(new PlainTableReader(
soptions,
file_size,
user_key_size,
key_prefix_len,
bloom_num_bits,
hash_table_ratio,
table_properties
@ -133,22 +121,69 @@ Iterator* PlainTableReader::NewIterator(const ReadOptions& options) {
return new PlainTableIterator(this);
}
Status PlainTableReader::PopulateIndex() {
// Get mmapped memory to file_data_.
Status s = file_->Read(0, file_size_, &file_data_, nullptr);
if (!s.ok()) {
return s;
}
version_ = DecodeFixed32(file_data_.data());
version_ ^= 0x80000000;
assert(version_ == 1);
data_start_offset_ = 4;
struct PlainTableReader::IndexRecord {
uint32_t hash; // hash of the prefix
uint32_t offset; // offset of a row
IndexRecord* next;
};
// Helper class to track all the index records
class PlainTableReader::IndexRecordList {
public:
explicit IndexRecordList(size_t num_records_per_group) :
num_records_per_group_(num_records_per_group),
current_group_(nullptr),
num_records_in_current_group_(num_records_per_group) {
}
~IndexRecordList() {
for (size_t i = 0; i < groups_.size(); i++) {
delete[] groups_[i];
}
}
void AddRecord(murmur_t hash, uint32_t offset) {
if (num_records_in_current_group_ == num_records_per_group_) {
current_group_ = AllocateNewGroup();
num_records_in_current_group_ = 0;
}
auto& new_record = current_group_[num_records_in_current_group_];
new_record.hash = hash;
new_record.offset = offset;
new_record.next = nullptr;
num_records_in_current_group_++;
}
size_t GetNumRecords() {
return (groups_.size() - 1) * num_records_per_group_
+ num_records_in_current_group_;
}
IndexRecord* At(size_t index) {
return &(groups_[index / num_records_per_group_]
[index % num_records_per_group_]);
}
IndexRecord* AllocateNewGroup() {
IndexRecord* result = new IndexRecord[num_records_per_group_];
groups_.push_back(result);
return result;
}
private:
const size_t num_records_per_group_;
IndexRecord* current_group_;
// List of arrays allocated
std::vector<IndexRecord*> groups_;
size_t num_records_in_current_group_;
};
int PlainTableReader::PopulateIndexRecordList(
IndexRecordList& record_list) {
Slice key_slice;
Slice key_prefix_slice;
Slice key_suffix_slice;
Slice value_slice;
Slice prev_key_prefix_slice;
uint32_t prev_key_prefix_hash = 0;
uint32_t pos = data_start_offset_;
int key_index_within_prefix = 0;
bool first = true;
@ -156,72 +191,104 @@ Status PlainTableReader::PopulateIndex() {
HistogramImpl keys_per_prefix_hist;
// Need map to be ordered to make sure sub indexes generated
// are in order.
std::vector<std::pair<Slice, std::string>> prefix_index_pairs;
std::string current_prefix_index;
int num_prefixes = 0;
while (pos < data_end_offset_) {
uint32_t key_offset = pos;
status_ = Next(pos, &key_slice, &value_slice, pos);
key_prefix_slice = Slice(key_slice.data(), key_prefix_len_);
key_prefix_slice = GetPrefix(key_slice);
if (first || prev_key_prefix_slice != key_prefix_slice) {
num_prefixes++;
if (!first) {
keys_per_prefix_hist.Add(key_index_within_prefix);
prefix_index_pairs.push_back(
std::make_pair<Slice, std::string>(
std::move(prev_key_prefix_slice),
std::move(current_prefix_index)));
current_prefix_index.clear();
}
key_index_within_prefix = 0;
prev_key_prefix_slice = key_prefix_slice;
prev_key_prefix_hash = GetSliceHash(key_prefix_slice);
}
if (key_index_within_prefix++ % 8 == 0) {
// Add an index key for every 8 keys
PutFixed32(&current_prefix_index, key_offset);
if (key_index_within_prefix++ % 16 == 0) {
// Add an index key for every 16 keys
record_list.AddRecord(prev_key_prefix_hash, key_offset);
}
first = false;
}
prefix_index_pairs.push_back(
std::make_pair<Slice, std::string>(std::move(prev_key_prefix_slice),
std::move(current_prefix_index)));
keys_per_prefix_hist.Add(key_index_within_prefix);
Log(options_.info_log, "Number of Keys per prefix Histogram: %s",
keys_per_prefix_hist.ToString().c_str());
return num_prefixes;
}
void PlainTableReader::Allocate(int num_prefixes) {
if (hash_table_ != nullptr) {
delete[] hash_table_;
}
std::vector<Slice> filter_entries(0); // for creating bloom filter;
if (filter_policy_ != nullptr) {
filter_entries.reserve(prefix_index_pairs.size());
if (bloom_bits_per_key_ > 0) {
bloom_ = new DynamicBloom(num_prefixes * bloom_bits_per_key_);
}
double hash_table_size_multipier =
(hash_table_ratio_ > 1.0) ? 1.0 : 1.0 / hash_table_ratio_;
hash_table_size_ = prefix_index_pairs.size() * hash_table_size_multipier + 1;
hash_table_size_ = num_prefixes * hash_table_size_multipier + 1;
hash_table_ = new uint32_t[hash_table_size_];
std::vector<std::string> hash2map(hash_table_size_);
}
size_t PlainTableReader::BucketizeIndexesAndFillBloom(
IndexRecordList& record_list, int num_prefixes,
std::vector<IndexRecord*>& hash2offsets,
std::vector<uint32_t>& bucket_count) {
size_t sub_index_size_needed = 0;
for (auto& p: prefix_index_pairs) {
auto& sub_index = hash2map[getBucketId(p.first, key_prefix_len_,
hash_table_size_)];
if (sub_index.length() > 0 || p.second.length() > kOffsetLen) {
if (sub_index.length() <= kOffsetLen) {
sub_index_size_needed += sub_index.length() + 4;
bool first = true;
uint32_t prev_hash = 0;
size_t num_records = record_list.GetNumRecords();
for (size_t i = 0; i < num_records; i++) {
IndexRecord* index_record = record_list.At(i);
uint32_t cur_hash = index_record->hash;
if (first || prev_hash != cur_hash) {
prev_hash = cur_hash;
first = false;
if (bloom_) {
bloom_->AddHash(cur_hash);
}
sub_index_size_needed += p.second.length();
}
sub_index.append(p.second);
if (filter_policy_ != nullptr) {
filter_entries.push_back(p.first);
uint32_t bucket = getBucketIdFromHash(cur_hash, hash_table_size_);
IndexRecord* prev_bucket_head = hash2offsets[bucket];
index_record->next = prev_bucket_head;
hash2offsets[bucket] = index_record;
if (bucket_count[bucket] > 0) {
if (bucket_count[bucket] == 1) {
sub_index_size_needed += kOffsetLen + 1;
}
if (bucket_count[bucket] == 127) {
// Need more than one byte for length
sub_index_size_needed++;
}
sub_index_size_needed += kOffsetLen;
}
bucket_count[bucket]++;
}
return sub_index_size_needed;
}
sub_index_.clear();
void PlainTableReader::FillIndexes(size_t sub_index_size_needed,
std::vector<IndexRecord*>& hash2offsets,
std::vector<uint32_t>& bucket_count) {
Log(options_.info_log, "Reserving %zu bytes for sub index",
sub_index_size_needed);
sub_index_.reserve(sub_index_size_needed);
// 4 bytes buffer for variable length size
size_t buffer_size = 64;
size_t buffer_used = 0;
sub_index_size_needed += buffer_size;
sub_index_ = new char[sub_index_size_needed];
size_t sub_index_offset = 0;
char* prev_ptr;
char* cur_ptr;
uint32_t* sub_index_ptr;
IndexRecord* record;
for (int i = 0; i < hash_table_size_; i++) {
uint32_t num_keys_for_bucket = hash2map[i].length() / kOffsetLen;
uint32_t num_keys_for_bucket = bucket_count[i];
switch (num_keys_for_bucket) {
case 0:
// No key for bucket
@ -229,58 +296,131 @@ Status PlainTableReader::PopulateIndex() {
break;
case 1:
// point directly to the file offset
hash_table_[i] = DecodeFixed32(hash2map[i].data());
hash_table_[i] = hash2offsets[i]->offset;
break;
default:
// point to index block
hash_table_[i] = sub_index_.length() | kSubIndexMask;
PutFixed32(&sub_index_, num_keys_for_bucket);
sub_index_.append(hash2map[i]);
// point to second level indexes.
hash_table_[i] = sub_index_offset | kSubIndexMask;
prev_ptr = sub_index_ + sub_index_offset;
cur_ptr = EncodeVarint32(prev_ptr, num_keys_for_bucket);
sub_index_offset += cur_ptr - prev_ptr;
if (cur_ptr - prev_ptr > 2
|| (cur_ptr - prev_ptr == 2 && num_keys_for_bucket <= 127)) {
// Need to resize sub_index. Exponentially grow buffer.
buffer_used += cur_ptr - prev_ptr - 1;
if (buffer_used + 4 > buffer_size) {
Log(options_.info_log, "Recalculate suffix_map length to %zu",
sub_index_size_needed);
sub_index_size_needed += buffer_size;
buffer_size *= 2;
char* new_sub_index = new char[sub_index_size_needed];
memcpy(new_sub_index, sub_index_, sub_index_offset);
delete[] sub_index_;
sub_index_ = new_sub_index;
}
}
sub_index_ptr = (uint32_t*) (sub_index_ + sub_index_offset);
record = hash2offsets[i];
int j;
for (j = num_keys_for_bucket - 1;
j >= 0 && record; j--, record = record->next) {
sub_index_ptr[j] = record->offset;
}
assert(j == -1 && record == nullptr);
sub_index_offset += kOffsetLen * num_keys_for_bucket;
break;
}
}
if (filter_policy_ != nullptr) {
filter_str_.clear();
filter_policy_->CreateFilter(&filter_entries[0], filter_entries.size(),
&filter_str_);
filter_slice_ = Slice(filter_str_.data(), filter_str_.size());
}
Log(options_.info_log, "hash table size: %d, suffix_map length %zu",
hash_table_size_, sub_index_.length());
Log(options_.info_log, "Number of Keys per prefix Histogram: %s",
keys_per_prefix_hist.ToString().c_str());
hash_table_size_, sub_index_size_needed);
}
// PopulateIndex() builds index of keys.
// hash_table_ contains buckets size of hash_table_size_, each is a 32-bit
// integer. The lower 31 bits contain an offset value (explained below) and
// the first bit of the integer indicates type of the offset:
//
// 0 indicates that the bucket contains only one prefix (no conflict when
// hashing this prefix), whose first row starts from this offset of the file.
// 1 indicates that the bucket contains more than one prefixes, or there
// are too many rows for one prefix so we need a binary search for it. In
// this case, the offset indicates the offset of sub_index_ holding the
// binary search indexes of keys for those rows. Those binary search indexes
// are organized in this way:
//
// The first 4 bytes, indicates how many indexes (N) are stored after it. After
// it, there are N 32-bit integers, each points of an offset of the file, which
// points to starting of a row. Those offsets need to be guaranteed to be in
// ascending order so the keys they are pointing to are also in ascending order
// to make sure we can use them to do binary searches.
Status PlainTableReader::PopulateIndex() {
// Get mmapped memory to file_data_.
Status s = file_->Read(0, file_size_, &file_data_, nullptr);
if (!s.ok()) {
return s;
}
IndexRecordList record_list(256);
// First, read the whole file, for every 16 rows for a prefix (starting from
// the first one), generate a record of (hash, offset) and append it to
// IndexRecordList, which is a data structure created to store them.
int num_prefixes = PopulateIndexRecordList(record_list);
// Calculated hash table and bloom filter size and allocate memory for indexes
// and bloom filter based on the number of prefixes.
Allocate(num_prefixes);
// Bucketize all the index records to a temp data structure, in which for
// each bucket, we generate a linked list of IndexRecord, in reversed order.
std::vector<IndexRecord*> hash2offsets(hash_table_size_, nullptr);
std::vector<uint32_t> bucket_count(hash_table_size_, 0);
size_t sub_index_size_needed = BucketizeIndexesAndFillBloom(record_list,
num_prefixes,
hash2offsets,
bucket_count);
// From the temp data structure, populate indexes.
FillIndexes(sub_index_size_needed, hash2offsets, bucket_count);
return Status::OK();
}
uint32_t PlainTableReader::GetOffset(const Slice& target,
bool& prefix_matched) {
Status PlainTableReader::GetOffset(const Slice& target, const Slice& prefix,
uint32_t prefix_hash, bool& prefix_matched,
uint32_t& ret_offset) {
prefix_matched = false;
int bucket = getBucketId(target, key_prefix_len_, hash_table_size_);
int bucket = getBucketIdFromHash(prefix_hash, hash_table_size_);
uint32_t bucket_value = hash_table_[bucket];
if (bucket_value == data_end_offset_) {
return data_end_offset_;
ret_offset = data_end_offset_;
return Status::OK();
} else if ((bucket_value & kSubIndexMask) == 0) {
// point directly to the file
return bucket_value;
ret_offset = bucket_value;
return Status::OK();
}
// point to sub-index, need to do a binary search
// point to sub-index, need to do a binary search
uint32_t low = 0;
uint64_t prefix_index_offset = bucket_value ^ kSubIndexMask;
uint32_t upper_bound = DecodeFixed32(sub_index_.data() + prefix_index_offset);
const char* index_ptr = sub_index_ + prefix_index_offset;
uint32_t upper_bound;
const uint32_t* base_ptr = (const uint32_t*) GetVarint32Ptr(index_ptr,
index_ptr + 4,
&upper_bound);
uint32_t high = upper_bound;
uint64_t base_offset = prefix_index_offset + 4;
Slice mid_key;
// The key is between [low, high). Do a binary search between it.
while (high - low > 1) {
uint32_t mid = (high + low) / 2;
const char* index_offset = sub_index_.data() + base_offset
+ kOffsetLen * mid;
uint32_t file_offset = DecodeFixed32(index_offset);
mid_key = Slice(file_data_.data() + file_offset, GetInternalKeyLength());
uint32_t file_offset = base_ptr[mid];
size_t tmp;
Status s = ReadKey(file_data_.data() + file_offset, &mid_key, tmp);
if (!s.ok()) {
return s;
}
int cmp_result = options_.comparator->Compare(target, mid_key);
if (cmp_result > 0) {
low = mid;
@ -289,38 +429,61 @@ uint32_t PlainTableReader::GetOffset(const Slice& target,
// Happen to have found the exact key or target is smaller than the
// first key after base_offset.
prefix_matched = true;
return file_offset;
ret_offset = file_offset;
return Status::OK();
} else {
high = mid;
}
}
}
// The key is between low and low+1 (if exists). Both of them can have the
// correct prefix. Need to rule out at least one, to avoid to miss the
// correct one.
uint32_t low_key_offset = DecodeFixed32(
sub_index_.data() + base_offset + kOffsetLen * low);
if (low + 1 < upper_bound) {
if (Slice(file_data_.data() + low_key_offset, key_prefix_len_)
== Slice(target.data(), key_prefix_len_)) {
prefix_matched = true;
} else {
prefix_matched = false;
return DecodeFixed32(
sub_index_.data() + base_offset + kOffsetLen * (low + 1));
}
} else {
// Both of the key at the position low or low+1 could share the same
// prefix as target. We need to rule out one of them to avoid to go
// to the wrong prefix.
Slice low_key;
size_t tmp;
uint32_t low_key_offset = base_ptr[low];
Status s = ReadKey(file_data_.data() + low_key_offset, &low_key, tmp);
if (GetPrefix(low_key) == prefix) {
prefix_matched = true;
ret_offset = low_key_offset;
} else if (low + 1 < upper_bound) {
// There is possible a next prefix, return it
prefix_matched = false;
ret_offset = base_ptr[low + 1];
} else {
// target is larger than a key of the last prefix in this bucket
// but with a different prefix. Key does not exist.
ret_offset = data_end_offset_;
}
return low_key_offset;
return Status::OK();
}
bool PlainTableReader::MayHavePrefix(const Slice& target_prefix) {
return filter_policy_ == nullptr
|| filter_policy_->KeyMayMatch(target_prefix, filter_slice_);
bool PlainTableReader::MayHavePrefix(uint32_t hash) {
return bloom_ == nullptr || bloom_->MayContainHash(hash);
}
Status PlainTableReader::ReadKey(const char* row_ptr, Slice* key,
size_t& bytes_read) {
const char* key_ptr;
bytes_read = 0;
size_t internal_key_size;
if (IsFixedLength()) {
internal_key_size = GetFixedInternalKeyLength();
key_ptr = row_ptr;
} else {
uint32_t key_size;
key_ptr = GetVarint32Ptr(row_ptr, file_data_.data() + data_end_offset_,
&key_size);
internal_key_size = (size_t) key_size;
bytes_read = key_ptr - row_ptr;
}
if (row_ptr + internal_key_size >= file_data_.data() + data_end_offset_) {
return Status::Corruption("Unable to read the next key");
}
*key = Slice(key_ptr, internal_key_size);
bytes_read += internal_key_size;
return Status::OK();
}
Status PlainTableReader::Next(uint32_t offset, Slice* key, Slice* value,
uint32_t& next_offset) {
@ -333,22 +496,17 @@ Status PlainTableReader::Next(uint32_t offset, Slice* key, Slice* value,
return Status::Corruption("Offset is out of file size");
}
int internal_key_size = GetInternalKeyLength();
if (offset + internal_key_size >= data_end_offset_) {
return Status::Corruption("Un able to read the next key");
}
const char* key_ptr = file_data_.data() + offset;
*key = Slice(key_ptr, internal_key_size);
const char* row_ptr = file_data_.data() + offset;
size_t bytes_for_key;
Status s = ReadKey(row_ptr, key, bytes_for_key);
uint32_t value_size;
const char* value_ptr = GetVarint32Ptr(key_ptr + internal_key_size,
const char* value_ptr = GetVarint32Ptr(row_ptr + bytes_for_key,
file_data_.data() + data_end_offset_,
&value_size);
if (value_ptr == nullptr) {
return Status::Corruption("Error reading value length.");
}
next_offset = offset + (value_ptr - key_ptr) + value_size;
next_offset = offset + (value_ptr - row_ptr) + value_size;
if (next_offset > data_end_offset_) {
return Status::Corruption("Reach end of file when reading value");
}
@ -362,13 +520,17 @@ Status PlainTableReader::Get(
bool (*saver)(void*, const Slice&, const Slice&, bool),
void (*mark_key_may_exist)(void*)) {
// Check bloom filter first.
if (!MayHavePrefix(Slice(target.data(), key_prefix_len_))) {
Slice prefix_slice = GetPrefix(target);
uint32_t prefix_hash = GetSliceHash(prefix_slice);
if (!MayHavePrefix(prefix_hash)) {
return Status::OK();
}
uint32_t offset;
bool prefix_match;
offset = GetOffset(target, prefix_match);
Status s = GetOffset(target, prefix_slice, prefix_hash, prefix_match, offset);
if (!s.ok()) {
return s;
}
Slice found_key;
Slice found_value;
while (offset < data_end_offset_) {
@ -379,8 +541,8 @@ Status PlainTableReader::Get(
if (!prefix_match) {
// Need to verify prefix for the first key found if it is not yet
// checked.
if (!target.starts_with(Slice(found_key.data(), key_prefix_len_))) {
break;
if (GetPrefix(found_key) != prefix_slice) {
return Status::OK();
}
prefix_match = true;
}
@ -403,7 +565,7 @@ uint64_t PlainTableReader::ApproximateOffsetOf(const Slice& key) {
PlainTableIterator::PlainTableIterator(PlainTableReader* table) :
table_(table) {
SeekToFirst();
next_offset_ = offset_ = table_->data_end_offset_;
}
PlainTableIterator::~PlainTableIterator() {
@ -416,7 +578,11 @@ bool PlainTableIterator::Valid() const {
void PlainTableIterator::SeekToFirst() {
next_offset_ = table_->data_start_offset_;
Next();
if (next_offset_ >= table_->data_end_offset_) {
next_offset_ = offset_ = table_->data_end_offset_;
} else {
Next();
}
}
void PlainTableIterator::SeekToLast() {
@ -424,18 +590,25 @@ void PlainTableIterator::SeekToLast() {
}
void PlainTableIterator::Seek(const Slice& target) {
if (!table_->MayHavePrefix(Slice(target.data(), table_->key_prefix_len_))) {
Slice prefix_slice = table_->GetPrefix(target);
uint32_t prefix_hash = GetSliceHash(prefix_slice);
if (!table_->MayHavePrefix(prefix_hash)) {
offset_ = next_offset_ = table_->data_end_offset_;
return;
}
bool prefix_match;
next_offset_ = table_->GetOffset(target, prefix_match);
status_ = table_->GetOffset(target, prefix_slice, prefix_hash, prefix_match,
next_offset_);
if (!status_.ok()) {
offset_ = next_offset_ = table_->data_end_offset_;
return;
}
if (next_offset_ < table_-> data_end_offset_) {
for (Next(); status_.ok() && Valid(); Next()) {
if (!prefix_match) {
// Need to verify the first key's prefix
if (!target.starts_with(Slice(key().data(), table_->key_prefix_len_))) {
if (table_->GetPrefix(key()) != prefix_slice) {
offset_ = next_offset_ = table_->data_end_offset_;
break;
}

View File

@ -9,6 +9,7 @@
#include "rocksdb/env.h"
#include "rocksdb/iterator.h"
#include "rocksdb/table.h"
#include "rocksdb/plain_table_factory.h"
namespace rocksdb {
@ -20,33 +21,12 @@ class RandomAccessFile;
struct ReadOptions;
class TableCache;
class TableReader;
class DynamicBloom;
using std::unique_ptr;
using std::unordered_map;
// Based on following output file format:
// +-------------+
// | version |
// +-------------+------------------------------+ <= key1_data_offset
// | key1 | value_size (4 bytes) | |
// +----------------------------------------+ |
// | value1 |
// | |
// +----------------------------------------+---+ <= key2_data_offset
// | key2 | value_size (4 bytes) | |
// +----------------------------------------+ |
// | value2 |
// | |
// | ...... |
// +-----------------+--------------------------+ <= index_block_offset
// | key1 | key1 offset (8 bytes) |
// +-----------------+--------------------------+ <= key2_index_offset
// | key2 | key2 offset (8 bytes) |
// +-----------------+--------------------------+ <= key3_index_offset
// | key3 | key3 offset (8 bytes) |
// +-----------------+--------------------------+ <= key4_index_offset
// | ...... |
// +-----------------+------------+-------------+
// Based on following output file format shown in plain_table_factory.h
// When opening the output file, IndexedTableReader creates a hash table
// from key prefixes to offset of the output file. IndexedTable will decide
// whether it points to the data offset of the first key with the key prefix
@ -58,8 +38,7 @@ class PlainTableReader: public TableReader {
public:
static Status Open(const Options& options, const EnvOptions& soptions,
unique_ptr<RandomAccessFile> && file, uint64_t file_size,
unique_ptr<TableReader>* table, const int user_key_size,
const int key_prefix_len, const int bloom_num_bits,
unique_ptr<TableReader>* table, const int bloom_num_bits,
double hash_table_ratio);
bool PrefixMayMatch(const Slice& internal_prefix);
@ -81,20 +60,18 @@ public:
return table_properties_;
}
PlainTableReader(
const EnvOptions& storage_options,
uint64_t file_size,
int user_key_size,
int key_prefix_len,
int bloom_num_bits,
double hash_table_ratio,
const TableProperties& table_properties);
PlainTableReader(const EnvOptions& storage_options, uint64_t file_size,
int bloom_num_bits, double hash_table_ratio,
const TableProperties& table_properties);
~PlainTableReader();
private:
struct IndexRecord;
class IndexRecordList;
uint32_t* hash_table_ = nullptr;
int hash_table_size_;
std::string sub_index_;
char* sub_index_ = nullptr;
Options options_;
const EnvOptions& soptions_;
@ -104,37 +81,67 @@ private:
Slice file_data_;
uint32_t version_;
uint32_t file_size_;
const size_t user_key_size_;
const size_t key_prefix_len_;
const double hash_table_ratio_;
const FilterPolicy* filter_policy_;
std::string filter_str_;
Slice filter_slice_;
const int bloom_bits_per_key_;
DynamicBloom* bloom_;
TableProperties table_properties_;
uint32_t data_start_offset_;
uint32_t data_end_offset_;
const uint32_t data_start_offset_;
const uint32_t data_end_offset_;
const size_t user_key_len_;
static const size_t kNumInternalBytes = 8;
static const uint32_t kSubIndexMask = 0x80000000;
static const size_t kOffsetLen = sizeof(uint32_t);
inline size_t GetInternalKeyLength() {
return user_key_size_ + kNumInternalBytes;
bool IsFixedLength() {
return user_key_len_ != PlainTableFactory::kVariableLength;
}
size_t GetFixedInternalKeyLength() {
return user_key_len_ + kNumInternalBytes;
}
friend class TableCache;
friend class PlainTableIterator;
// Internal helper function to generate an IndexRecordList object from all
// the rows, which contains index records as a list.
int PopulateIndexRecordList(IndexRecordList& record_list);
// Internal helper function to allocate memory for indexes and bloom filters
void Allocate(int num_prefixes);
// Internal helper function to bucket index record list to hash buckets.
// hash2offsets is sized of of hash_table_size_, each contains a linked list
// of offsets for the hash, in reversed order.
// bucket_count is sized of hash_table_size_. The value is how many index
// records are there in hash2offsets for the same bucket.
size_t BucketizeIndexesAndFillBloom(
IndexRecordList& record_list, int num_prefixes,
std::vector<IndexRecord*>& hash2offsets,
std::vector<uint32_t>& bucket_count);
// Internal helper class to fill the indexes and bloom filters to internal
// data structures. hash2offsets and bucket_count are bucketized indexes and
// counts generated by BucketizeIndexesAndFillBloom().
void FillIndexes(size_t sub_index_size_needed,
std::vector<IndexRecord*>& hash2offsets,
std::vector<uint32_t>& bucket_count);
// Populate the internal indexes. It must be called before
// any query to the table.
// This query will populate the hash table hash_table_, the second
// level of indexes sub_index_ and bloom filter filter_slice_ if enabled.
Status PopulateIndex();
// Check bloom filter to see whether it might contain this prefix
bool MayHavePrefix(const Slice& target_prefix);
// Check bloom filter to see whether it might contain this prefix.
// The hash of the prefix is given, since it can be reused for index lookup
// too.
bool MayHavePrefix(uint32_t hash);
Status ReadKey(const char* row_ptr, Slice* key, size_t& bytes_read);
// Read the key and value at offset to key and value.
// tmp_slice is a tmp slice.
// return next_offset as the offset for the next key.
@ -142,7 +149,15 @@ private:
// Get file offset for key target.
// return value prefix_matched is set to true if the offset is confirmed
// for a key with the same prefix as target.
uint32_t GetOffset(const Slice& target, bool& prefix_matched);
Status GetOffset(const Slice& target, const Slice& prefix,
uint32_t prefix_hash, bool& prefix_matched,
uint32_t& ret_offset);
Slice GetPrefix(const Slice& target) {
assert(target.size() >= 8); // target is internal key
return options_.prefix_extractor->Transform(
Slice(target.data(), target.size() - 8));
}
// No copying allowed
explicit PlainTableReader(const TableReader&) = delete;

View File

@ -104,6 +104,10 @@ const std::string TablePropertiesNames::kNumEntries =
"rocksdb.num.entries";
const std::string TablePropertiesNames::kFilterPolicy =
"rocksdb.filter.policy";
const std::string TablePropertiesNames::kFormatVersion =
"rocksdb.format.version";
const std::string TablePropertiesNames::kFixedKeyLen =
"rocksdb.fixed.key.length";
extern const std::string kPropertiesBlock = "rocksdb.properties";

View File

@ -8,7 +8,6 @@
#include "rocksdb/db.h"
#include "rocksdb/slice_transform.h"
#include "rocksdb/table.h"
#include "rocksdb/slice_transform.h"
#include "db/db_impl.h"
#include "db/dbformat.h"
#include "port/atomic_pointer.h"
@ -242,9 +241,10 @@ int main(int argc, char** argv) {
if (FLAGS_plain_table) {
options.allow_mmap_reads = true;
env_options.use_mmap_reads = true;
tf = new rocksdb::PlainTableFactory(16, FLAGS_prefix_len,
(FLAGS_prefix_len == 16) ? 0 : 8,
tf = new rocksdb::PlainTableFactory(16, (FLAGS_prefix_len == 16) ? 0 : 8,
0.75);
options.prefix_extractor = rocksdb::NewFixedPrefixTransform(
FLAGS_prefix_len);
} else {
tf = new rocksdb::BlockBasedTableFactory();
}

View File

@ -22,8 +22,8 @@
#include "rocksdb/env.h"
#include "rocksdb/iterator.h"
#include "rocksdb/memtablerep.h"
#include "table/meta_blocks.h"
#include "rocksdb/plain_table_factory.h"
#include "table/block_based_table_builder.h"
#include "table/block_based_table_factory.h"
#include "table/block_based_table_reader.h"
@ -124,8 +124,9 @@ class StringSink: public WritableFile {
class StringSource: public RandomAccessFile {
public:
StringSource(const Slice& contents, uint64_t uniq_id)
: contents_(contents.data(), contents.size()), uniq_id_(uniq_id) {
StringSource(const Slice& contents, uint64_t uniq_id, bool mmap)
: contents_(contents.data(), contents.size()), uniq_id_(uniq_id),
mmap_(mmap) {
}
virtual ~StringSource() { }
@ -140,8 +141,12 @@ class StringSource: public RandomAccessFile {
if (offset + n > contents_.size()) {
n = contents_.size() - offset;
}
memcpy(scratch, &contents_[offset], n);
*result = Slice(scratch, n);
if (!mmap_) {
memcpy(scratch, &contents_[offset], n);
*result = Slice(scratch, n);
} else {
*result = Slice(&contents_[offset], n);
}
return Status::OK();
}
@ -159,6 +164,7 @@ class StringSource: public RandomAccessFile {
private:
std::string contents_;
uint64_t uniq_id_;
bool mmap_;
};
typedef std::map<std::string, std::string, anon::STLLessThan> KVMap;
@ -245,89 +251,6 @@ class BlockConstructor: public Constructor {
BlockConstructor();
};
class BlockBasedTableConstructor: public Constructor {
public:
explicit BlockBasedTableConstructor(
const Comparator* cmp)
: Constructor(cmp) {
}
~BlockBasedTableConstructor() {
Reset();
}
virtual Status FinishImpl(const Options& options, const KVMap& data) {
Reset();
sink_.reset(new StringSink());
std::unique_ptr<FlushBlockBySizePolicyFactory> flush_policy_factory(
new FlushBlockBySizePolicyFactory(options.block_size,
options.block_size_deviation));
BlockBasedTableBuilder builder(
options,
sink_.get(),
flush_policy_factory.get(),
options.compression);
for (KVMap::const_iterator it = data.begin();
it != data.end();
++it) {
builder.Add(it->first, it->second);
ASSERT_TRUE(builder.status().ok());
}
Status s = builder.Finish();
ASSERT_TRUE(s.ok()) << s.ToString();
ASSERT_EQ(sink_->contents().size(), builder.FileSize());
// 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(),
&table_reader_);
}
virtual Iterator* NewIterator() const {
return table_reader_->NewIterator(ReadOptions());
}
uint64_t ApproximateOffsetOf(const Slice& key) const {
return table_reader_->ApproximateOffsetOf(key);
}
virtual Status Reopen(const Options& options) {
source_.reset(new StringSource(sink_->contents(), uniq_id_));
return options.table_factory->GetTableReader(options, soptions,
std::move(source_),
sink_->contents().size(),
&table_reader_);
}
virtual TableReader* table_reader() {
return table_reader_.get();
}
private:
void Reset() {
uniq_id_ = 0;
table_reader_.reset();
sink_.reset();
source_.reset();
}
uint64_t uniq_id_;
unique_ptr<StringSink> sink_;
unique_ptr<StringSource> source_;
unique_ptr<TableReader> table_reader_;
BlockBasedTableConstructor();
static uint64_t cur_uniq_id_;
const EnvOptions soptions;
};
uint64_t BlockBasedTableConstructor::cur_uniq_id_ = 1;
// A helper class that converts internal format keys into user keys
class KeyConvertingIterator: public Iterator {
public:
@ -369,6 +292,102 @@ class KeyConvertingIterator: public Iterator {
void operator=(const KeyConvertingIterator&);
};
class TableConstructor: public Constructor {
public:
explicit TableConstructor(
const Comparator* cmp, bool convert_to_internal_key = false)
: Constructor(cmp),
convert_to_internal_key_(convert_to_internal_key) {
}
~TableConstructor() {
Reset();
}
virtual Status FinishImpl(const Options& options, const KVMap& data) {
Reset();
sink_.reset(new StringSink());
unique_ptr<TableBuilder> builder;
builder.reset(
options.table_factory->GetTableBuilder(options, sink_.get(),
options.compression));
for (KVMap::const_iterator it = data.begin();
it != data.end();
++it) {
if (convert_to_internal_key_) {
ParsedInternalKey ikey(it->first, kMaxSequenceNumber, kTypeValue);
std::string encoded;
AppendInternalKey(&encoded, ikey);
builder->Add(encoded, it->second);
} else {
builder->Add(it->first, it->second);
}
ASSERT_TRUE(builder->status().ok());
}
Status s = builder->Finish();
ASSERT_TRUE(s.ok()) << s.ToString();
ASSERT_EQ(sink_->contents().size(), builder->FileSize());
// Open the table
uniq_id_ = cur_uniq_id_++;
source_.reset(
new StringSource(sink_->contents(), uniq_id_,
options.allow_mmap_reads));
unique_ptr<TableFactory> table_factory;
return options.table_factory->GetTableReader(options, soptions,
std::move(source_),
sink_->contents().size(),
&table_reader_);
}
virtual Iterator* NewIterator() const {
Iterator* iter = table_reader_->NewIterator(ReadOptions());
if (convert_to_internal_key_) {
return new KeyConvertingIterator(iter);
} else {
return iter;
}
}
uint64_t ApproximateOffsetOf(const Slice& key) const {
return table_reader_->ApproximateOffsetOf(key);
}
virtual Status Reopen(const Options& options) {
source_.reset(
new StringSource(sink_->contents(), uniq_id_,
options.allow_mmap_reads));
return options.table_factory->GetTableReader(options, soptions,
std::move(source_),
sink_->contents().size(),
&table_reader_);
}
virtual TableReader* table_reader() {
return table_reader_.get();
}
private:
void Reset() {
uniq_id_ = 0;
table_reader_.reset();
sink_.reset();
source_.reset();
}
bool convert_to_internal_key_;
uint64_t uniq_id_;
unique_ptr<StringSink> sink_;
unique_ptr<StringSource> source_;
unique_ptr<TableReader> table_reader_;
TableConstructor();
static uint64_t cur_uniq_id_;
const EnvOptions soptions;
};
uint64_t TableConstructor::cur_uniq_id_ = 1;
class MemTableConstructor: public Constructor {
public:
explicit MemTableConstructor(const Comparator* cmp)
@ -481,7 +500,9 @@ static bool BZip2CompressionSupported() {
#endif
enum TestType {
TABLE_TEST,
BLOCK_BASED_TABLE_TEST,
PLAIN_TABLE_SEMI_FIXED_PREFIX,
PLAIN_TABLE_FULL_STR_PREFIX,
BLOCK_TEST,
MEMTABLE_TEST,
DB_TEST
@ -497,8 +518,10 @@ struct TestArgs {
static std::vector<TestArgs> GenerateArgList() {
std::vector<TestArgs> ret;
TestType test_type[4] = {TABLE_TEST, BLOCK_TEST, MEMTABLE_TEST, DB_TEST};
int test_type_len = 4;
TestType test_type[6] = { BLOCK_BASED_TABLE_TEST,
PLAIN_TABLE_SEMI_FIXED_PREFIX, PLAIN_TABLE_FULL_STR_PREFIX, BLOCK_TEST,
MEMTABLE_TEST, DB_TEST };
int test_type_len = 6;
bool reverse_compare[2] = {false, true};
int reverse_compare_len = 2;
int restart_interval[3] = {16, 1, 1024};
@ -523,20 +546,66 @@ static std::vector<TestArgs> GenerateArgList() {
#endif
for(int i =0; i < test_type_len; i++)
for (int j =0; j < reverse_compare_len; j++)
for (int k =0; k < restart_interval_len; k++)
for (unsigned int n =0; n < compression_types.size(); n++) {
TestArgs one_arg;
one_arg.type = test_type[i];
one_arg.reverse_compare = reverse_compare[j];
one_arg.restart_interval = restart_interval[k];
one_arg.compression = compression_types[n];
ret.push_back(one_arg);
}
for (int j =0; j < reverse_compare_len; j++) {
if (test_type[i] == PLAIN_TABLE_SEMI_FIXED_PREFIX
|| test_type[i] == PLAIN_TABLE_FULL_STR_PREFIX) {
// Plain table doesn't use restart index or compression.
TestArgs one_arg;
one_arg.type = test_type[i];
one_arg.reverse_compare = reverse_compare[0];
one_arg.restart_interval = restart_interval[0];
one_arg.compression = compression_types[0];
ret.push_back(one_arg);
continue;
}
for (int k = 0; k < restart_interval_len; k++)
for (unsigned int n = 0; n < compression_types.size(); n++) {
TestArgs one_arg;
one_arg.type = test_type[i];
one_arg.reverse_compare = reverse_compare[j];
one_arg.restart_interval = restart_interval[k];
one_arg.compression = compression_types[n];
ret.push_back(one_arg);
}
}
return ret;
}
// In order to make all tests run for plain table format, including
// those operating on empty keys, create a new prefix transformer which
// return fixed prefix if the slice is not shorter than the prefix length,
// and the full slice if it is shorter.
class FixedOrLessPrefixTransform : public SliceTransform {
private:
const size_t prefix_len_;
public:
explicit FixedOrLessPrefixTransform(size_t prefix_len) :
prefix_len_(prefix_len) {
}
virtual const char* Name() const {
return "rocksdb.FixedPrefix";
}
virtual Slice Transform(const Slice& src) const {
assert(InDomain(src));
if (src.size() < prefix_len_) {
return src;
}
return Slice(src.data(), prefix_len_);
}
virtual bool InDomain(const Slice& src) const {
return true;
}
virtual bool InRange(const Slice& dst) const {
return (dst.size() <= prefix_len_);
}
};
class Harness {
public:
Harness() : constructor_(nullptr) { }
@ -554,9 +623,35 @@ class Harness {
if (args.reverse_compare) {
options_.comparator = &reverse_key_comparator;
}
internal_comparator_.reset(new InternalKeyComparator(options_.comparator));
support_prev_ = true;
only_support_prefix_seek_ = false;
BlockBasedTableFactory::TableOptions table_options;
switch (args.type) {
case TABLE_TEST:
constructor_ = new BlockBasedTableConstructor(options_.comparator);
case BLOCK_BASED_TABLE_TEST:
table_options.flush_block_policy_factory.reset(
new FlushBlockBySizePolicyFactory(options_.block_size,
options_.block_size_deviation));
options_.table_factory.reset(new BlockBasedTableFactory(table_options));
constructor_ = new TableConstructor(options_.comparator);
break;
case PLAIN_TABLE_SEMI_FIXED_PREFIX:
support_prev_ = false;
only_support_prefix_seek_ = true;
options_.prefix_extractor = new FixedOrLessPrefixTransform(2);
options_.allow_mmap_reads = true;
options_.table_factory.reset(new PlainTableFactory());
constructor_ = new TableConstructor(options_.comparator, true);
options_.comparator = internal_comparator_.get();
break;
case PLAIN_TABLE_FULL_STR_PREFIX:
support_prev_ = false;
only_support_prefix_seek_ = true;
options_.prefix_extractor = NewNoopTransform();
options_.allow_mmap_reads = true;
options_.table_factory.reset(new PlainTableFactory());
constructor_ = new TableConstructor(options_.comparator, true);
options_.comparator = internal_comparator_.get();
break;
case BLOCK_TEST:
constructor_ = new BlockConstructor(options_.comparator);
@ -584,7 +679,9 @@ class Harness {
constructor_->Finish(options_, &keys, &data);
TestForwardScan(keys, data);
TestBackwardScan(keys, data);
if (support_prev_) {
TestBackwardScan(keys, data);
}
TestRandomAccess(rnd, keys, data);
}
@ -627,7 +724,7 @@ class Harness {
KVMap::const_iterator model_iter = data.begin();
if (kVerbose) fprintf(stderr, "---\n");
for (int i = 0; i < 200; i++) {
const int toss = rnd->Uniform(5);
const int toss = rnd->Uniform(support_prev_ ? 5 : 3);
switch (toss) {
case 0: {
if (iter->Valid()) {
@ -719,17 +816,20 @@ class Harness {
} else {
const int index = rnd->Uniform(keys.size());
std::string result = keys[index];
switch (rnd->Uniform(3)) {
switch (rnd->Uniform(support_prev_ ? 3 : 1)) {
case 0:
// Return an existing key
break;
case 1: {
// Attempt to return something smaller than an existing key
if (result.size() > 0 && result[result.size()-1] > '\0') {
result[result.size()-1]--;
if (result.size() > 0 && result[result.size() - 1] > '\0'
&& (!only_support_prefix_seek_
|| options_.prefix_extractor->Transform(result).size()
< result.size())) {
result[result.size() - 1]--;
}
break;
}
}
case 2: {
// Return something larger than an existing key
Increment(options_.comparator, &result);
@ -746,6 +846,9 @@ class Harness {
private:
Options options_ = Options();
Constructor* constructor_;
bool support_prev_;
bool only_support_prefix_seek_;
shared_ptr<Comparator> internal_comparator_;
};
static bool Between(uint64_t val, uint64_t low, uint64_t high) {
@ -763,8 +866,8 @@ class TableTest { };
// This test include all the basic checks except those for index size and block
// size, which will be conducted in separated unit tests.
TEST(TableTest, BasicBlockedBasedTableProperties) {
BlockBasedTableConstructor c(BytewiseComparator());
TEST(TableTest, BasicTableProperties) {
TableConstructor c(BytewiseComparator());
c.Add("a1", "val1");
c.Add("b2", "val2");
@ -824,7 +927,7 @@ TEST(TableTest, BasicPlainTableProperties) {
}
ASSERT_OK(builder->Finish());
StringSource source(sink.contents(), 72242);
StringSource source(sink.contents(), 72242, true);
TableProperties props;
auto s = ReadTableProperties(
@ -849,7 +952,7 @@ TEST(TableTest, BasicPlainTableProperties) {
}
TEST(TableTest, FilterPolicyNameProperties) {
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
c.Add("a1", "val1");
std::vector<std::string> keys;
KVMap kvmap;
@ -889,7 +992,7 @@ TEST(TableTest, IndexSizeStat) {
// Each time we load one more key to the table. the table index block
// size is expected to be larger than last time's.
for (size_t i = 1; i < keys.size(); ++i) {
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
for (size_t j = 0; j < i; ++j) {
c.Add(keys[j], "val");
}
@ -910,7 +1013,7 @@ TEST(TableTest, IndexSizeStat) {
TEST(TableTest, NumBlockStat) {
Random rnd(test::RandomSeed());
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
Options options;
options.compression = kNoCompression;
options.block_restart_interval = 1;
@ -986,7 +1089,7 @@ TEST(TableTest, BlockCacheTest) {
std::vector<std::string> keys;
KVMap kvmap;
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
c.Add("key", "value");
c.Finish(options, &keys, &kvmap);
@ -1107,7 +1210,7 @@ TEST(TableTest, BlockCacheTest) {
}
TEST(TableTest, ApproximateOffsetOfPlain) {
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
c.Add("k01", "hello");
c.Add("k02", "hello2");
c.Add("k03", std::string(10000, 'x'));
@ -1138,7 +1241,7 @@ TEST(TableTest, ApproximateOffsetOfPlain) {
static void Do_Compression_Test(CompressionType comp) {
Random rnd(301);
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
std::string tmp;
c.Add("k01", "hello");
c.Add("k02", test::CompressibleString(&rnd, 0.25, 10000, &tmp));
@ -1156,7 +1259,7 @@ static void Do_Compression_Test(CompressionType comp) {
ASSERT_TRUE(Between(c.ApproximateOffsetOf("k02"), 0, 0));
ASSERT_TRUE(Between(c.ApproximateOffsetOf("k03"), 2000, 3000));
ASSERT_TRUE(Between(c.ApproximateOffsetOf("k04"), 2000, 3000));
ASSERT_TRUE(Between(c.ApproximateOffsetOf("xyz"), 4000, 6000));
ASSERT_TRUE(Between(c.ApproximateOffsetOf("xyz"), 4000, 6100));
}
TEST(TableTest, ApproximateOffsetOfCompressed) {
@ -1194,7 +1297,7 @@ TEST(TableTest, BlockCacheLeak) {
opt.block_cache = NewLRUCache(16*1024*1024); // big enough so we don't ever
// lose cached values.
BlockBasedTableConstructor c(BytewiseComparator());
TableConstructor c(BytewiseComparator());
c.Add("k01", "hello");
c.Add("k02", "hello2");
c.Add("k03", std::string(10000, 'x'));

View File

@ -39,7 +39,10 @@ DynamicBloom::DynamicBloom(uint32_t total_bits,
}
void DynamicBloom::Add(const Slice& key) {
uint32_t h = hash_func_(key);
AddHash(hash_func_(key));
}
void DynamicBloom::AddHash(uint32_t h) {
const uint32_t delta = (h >> 17) | (h << 15); // Rotate right 17 bits
for (uint32_t i = 0; i < num_probes_; i++) {
const uint32_t bitpos = h % total_bits_;
@ -49,7 +52,10 @@ void DynamicBloom::Add(const Slice& key) {
}
bool DynamicBloom::MayContain(const Slice& key) {
uint32_t h = hash_func_(key);
return (MayContainHash(hash_func_(key)));
}
bool DynamicBloom::MayContainHash(uint32_t h) {
const uint32_t delta = (h >> 17) | (h << 15); // Rotate right 17 bits
for (uint32_t i = 0; i < num_probes_; i++) {
const uint32_t bitpos = h % total_bits_;

View File

@ -28,9 +28,14 @@ class DynamicBloom {
// Assuming single threaded access to Add
void Add(const Slice& key);
// Assuming single threaded access to Add
void AddHash(uint32_t hash);
// Multithreaded access to MayContain is OK
bool MayContain(const Slice& key);
// Multithreaded access to MayContain is OK
bool MayContainHash(uint32_t hash);
private:
uint32_t (*hash_func_)(const Slice& key);