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-rw-r--r--src/rocksdb/table/plain/plain_table_reader.cc765
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diff --git a/src/rocksdb/table/plain/plain_table_reader.cc b/src/rocksdb/table/plain/plain_table_reader.cc
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+// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef ROCKSDB_LITE
+
+#include "table/plain/plain_table_reader.h"
+
+#include <string>
+#include <vector>
+
+#include "db/dbformat.h"
+#include "memory/arena.h"
+#include "monitoring/histogram.h"
+#include "monitoring/perf_context_imp.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/comparator.h"
+#include "rocksdb/env.h"
+#include "rocksdb/filter_policy.h"
+#include "rocksdb/options.h"
+#include "rocksdb/statistics.h"
+#include "table/block_based/block.h"
+#include "table/block_based/filter_block.h"
+#include "table/format.h"
+#include "table/get_context.h"
+#include "table/internal_iterator.h"
+#include "table/meta_blocks.h"
+#include "table/plain/plain_table_bloom.h"
+#include "table/plain/plain_table_factory.h"
+#include "table/plain/plain_table_key_coding.h"
+#include "table/two_level_iterator.h"
+#include "util/coding.h"
+#include "util/dynamic_bloom.h"
+#include "util/hash.h"
+#include "util/stop_watch.h"
+#include "util/string_util.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+namespace {
+
+// Safely getting a uint32_t element from a char array, where, starting from
+// `base`, every 4 bytes are considered as an fixed 32 bit integer.
+inline uint32_t GetFixed32Element(const char* base, size_t offset) {
+ return DecodeFixed32(base + offset * sizeof(uint32_t));
+}
+} // namespace
+
+// Iterator to iterate IndexedTable
+class PlainTableIterator : public InternalIterator {
+ public:
+ explicit PlainTableIterator(PlainTableReader* table, bool use_prefix_seek);
+ // No copying allowed
+ PlainTableIterator(const PlainTableIterator&) = delete;
+ void operator=(const Iterator&) = delete;
+
+ ~PlainTableIterator() override;
+
+ bool Valid() const override;
+
+ void SeekToFirst() override;
+
+ void SeekToLast() override;
+
+ void Seek(const Slice& target) override;
+
+ void SeekForPrev(const Slice& target) override;
+
+ void Next() override;
+
+ void Prev() override;
+
+ Slice key() const override;
+
+ Slice value() const override;
+
+ Status status() const override;
+
+ private:
+ PlainTableReader* table_;
+ PlainTableKeyDecoder decoder_;
+ bool use_prefix_seek_;
+ uint32_t offset_;
+ uint32_t next_offset_;
+ Slice key_;
+ Slice value_;
+ Status status_;
+};
+
+extern const uint64_t kPlainTableMagicNumber;
+PlainTableReader::PlainTableReader(
+ const ImmutableOptions& ioptions,
+ std::unique_ptr<RandomAccessFileReader>&& file,
+ const EnvOptions& storage_options, const InternalKeyComparator& icomparator,
+ EncodingType encoding_type, uint64_t file_size,
+ const TableProperties* table_properties,
+ const SliceTransform* prefix_extractor)
+ : internal_comparator_(icomparator),
+ encoding_type_(encoding_type),
+ full_scan_mode_(false),
+ user_key_len_(static_cast<uint32_t>(table_properties->fixed_key_len)),
+ prefix_extractor_(prefix_extractor),
+ enable_bloom_(false),
+ bloom_(6),
+ file_info_(std::move(file), storage_options,
+ static_cast<uint32_t>(table_properties->data_size)),
+ ioptions_(ioptions),
+ file_size_(file_size),
+ table_properties_(nullptr) {}
+
+PlainTableReader::~PlainTableReader() {
+ // Should fix?
+ status_.PermitUncheckedError();
+}
+
+Status PlainTableReader::Open(
+ const ImmutableOptions& ioptions, const EnvOptions& env_options,
+ const InternalKeyComparator& internal_comparator,
+ std::unique_ptr<RandomAccessFileReader>&& file, uint64_t file_size,
+ std::unique_ptr<TableReader>* table_reader, const int bloom_bits_per_key,
+ double hash_table_ratio, size_t index_sparseness, size_t huge_page_tlb_size,
+ bool full_scan_mode, const bool immortal_table,
+ const SliceTransform* prefix_extractor) {
+ if (file_size > PlainTableIndex::kMaxFileSize) {
+ return Status::NotSupported("File is too large for PlainTableReader!");
+ }
+
+ std::unique_ptr<TableProperties> props;
+ auto s = ReadTableProperties(file.get(), file_size, kPlainTableMagicNumber,
+ ioptions, &props);
+ if (!s.ok()) {
+ return s;
+ }
+
+ assert(hash_table_ratio >= 0.0);
+ auto& user_props = props->user_collected_properties;
+ auto prefix_extractor_in_file = props->prefix_extractor_name;
+
+ if (!full_scan_mode &&
+ !prefix_extractor_in_file.empty() /* old version sst file*/
+ && prefix_extractor_in_file != "nullptr") {
+ if (!prefix_extractor) {
+ return Status::InvalidArgument(
+ "Prefix extractor is missing when opening a PlainTable built "
+ "using a prefix extractor");
+ } else if (prefix_extractor_in_file != prefix_extractor->AsString()) {
+ return Status::InvalidArgument(
+ "Prefix extractor given doesn't match the one used to build "
+ "PlainTable");
+ }
+ }
+
+ EncodingType encoding_type = kPlain;
+ auto encoding_type_prop =
+ user_props.find(PlainTablePropertyNames::kEncodingType);
+ if (encoding_type_prop != user_props.end()) {
+ encoding_type = static_cast<EncodingType>(
+ DecodeFixed32(encoding_type_prop->second.c_str()));
+ }
+
+ std::unique_ptr<PlainTableReader> new_reader(new PlainTableReader(
+ ioptions, std::move(file), env_options, internal_comparator,
+ encoding_type, file_size, props.get(), prefix_extractor));
+
+ s = new_reader->MmapDataIfNeeded();
+ if (!s.ok()) {
+ return s;
+ }
+
+ if (!full_scan_mode) {
+ s = new_reader->PopulateIndex(props.get(), bloom_bits_per_key,
+ hash_table_ratio, index_sparseness,
+ huge_page_tlb_size);
+ if (!s.ok()) {
+ return s;
+ }
+ } else {
+ // Flag to indicate it is a full scan mode so that none of the indexes
+ // can be used.
+ new_reader->full_scan_mode_ = true;
+ }
+ // PopulateIndex can add to the props, so don't store them until now
+ new_reader->table_properties_ = std::move(props);
+
+ if (immortal_table && new_reader->file_info_.is_mmap_mode) {
+ new_reader->dummy_cleanable_.reset(new Cleanable());
+ }
+
+ *table_reader = std::move(new_reader);
+ return s;
+}
+
+void PlainTableReader::SetupForCompaction() {}
+
+InternalIterator* PlainTableReader::NewIterator(
+ const ReadOptions& options, const SliceTransform* /* prefix_extractor */,
+ Arena* arena, bool /*skip_filters*/, TableReaderCaller /*caller*/,
+ size_t /*compaction_readahead_size*/, bool /* allow_unprepared_value */) {
+ // Not necessarily used here, but make sure this has been initialized
+ assert(table_properties_);
+
+ // Auto prefix mode is not implemented in PlainTable.
+ bool use_prefix_seek = !IsTotalOrderMode() && !options.total_order_seek &&
+ !options.auto_prefix_mode;
+ if (arena == nullptr) {
+ return new PlainTableIterator(this, use_prefix_seek);
+ } else {
+ auto mem = arena->AllocateAligned(sizeof(PlainTableIterator));
+ return new (mem) PlainTableIterator(this, use_prefix_seek);
+ }
+}
+
+Status PlainTableReader::PopulateIndexRecordList(
+ PlainTableIndexBuilder* index_builder,
+ std::vector<uint32_t>* prefix_hashes) {
+ Slice prev_key_prefix_slice;
+ std::string prev_key_prefix_buf;
+ uint32_t pos = data_start_offset_;
+
+ bool is_first_record = true;
+ Slice key_prefix_slice;
+ PlainTableKeyDecoder decoder(&file_info_, encoding_type_, user_key_len_,
+ prefix_extractor_);
+ while (pos < file_info_.data_end_offset) {
+ uint32_t key_offset = pos;
+ ParsedInternalKey key;
+ Slice value_slice;
+ bool seekable = false;
+ Status s = Next(&decoder, &pos, &key, nullptr, &value_slice, &seekable);
+ if (!s.ok()) {
+ return s;
+ }
+
+ key_prefix_slice = GetPrefix(key);
+ if (enable_bloom_) {
+ bloom_.AddHash(GetSliceHash(key.user_key));
+ } else {
+ if (is_first_record || prev_key_prefix_slice != key_prefix_slice) {
+ if (!is_first_record) {
+ prefix_hashes->push_back(GetSliceHash(prev_key_prefix_slice));
+ }
+ if (file_info_.is_mmap_mode) {
+ prev_key_prefix_slice = key_prefix_slice;
+ } else {
+ prev_key_prefix_buf = key_prefix_slice.ToString();
+ prev_key_prefix_slice = prev_key_prefix_buf;
+ }
+ }
+ }
+
+ index_builder->AddKeyPrefix(GetPrefix(key), key_offset);
+
+ if (!seekable && is_first_record) {
+ return Status::Corruption("Key for a prefix is not seekable");
+ }
+
+ is_first_record = false;
+ }
+
+ prefix_hashes->push_back(GetSliceHash(key_prefix_slice));
+ auto s = index_.InitFromRawData(index_builder->Finish());
+ return s;
+}
+
+void PlainTableReader::AllocateBloom(int bloom_bits_per_key, int num_keys,
+ size_t huge_page_tlb_size) {
+ uint32_t bloom_total_bits = num_keys * bloom_bits_per_key;
+ if (bloom_total_bits > 0) {
+ enable_bloom_ = true;
+ bloom_.SetTotalBits(&arena_, bloom_total_bits, ioptions_.bloom_locality,
+ huge_page_tlb_size, ioptions_.logger);
+ }
+}
+
+void PlainTableReader::FillBloom(const std::vector<uint32_t>& prefix_hashes) {
+ assert(bloom_.IsInitialized());
+ for (const auto prefix_hash : prefix_hashes) {
+ bloom_.AddHash(prefix_hash);
+ }
+}
+
+Status PlainTableReader::MmapDataIfNeeded() {
+ if (file_info_.is_mmap_mode) {
+ // Get mmapped memory.
+ return file_info_.file->Read(
+ IOOptions(), 0, static_cast<size_t>(file_size_), &file_info_.file_data,
+ nullptr, nullptr, Env::IO_TOTAL /* rate_limiter_priority */);
+ }
+ return Status::OK();
+}
+
+Status PlainTableReader::PopulateIndex(TableProperties* props,
+ int bloom_bits_per_key,
+ double hash_table_ratio,
+ size_t index_sparseness,
+ size_t huge_page_tlb_size) {
+ assert(props != nullptr);
+
+ BlockContents index_block_contents;
+ Status s = ReadMetaBlock(file_info_.file.get(), nullptr /* prefetch_buffer */,
+ file_size_, kPlainTableMagicNumber, ioptions_,
+ PlainTableIndexBuilder::kPlainTableIndexBlock,
+ BlockType::kIndex, &index_block_contents);
+
+ bool index_in_file = s.ok();
+
+ BlockContents bloom_block_contents;
+ bool bloom_in_file = false;
+ // We only need to read the bloom block if index block is in file.
+ if (index_in_file) {
+ s = ReadMetaBlock(file_info_.file.get(), nullptr /* prefetch_buffer */,
+ file_size_, kPlainTableMagicNumber, ioptions_,
+ BloomBlockBuilder::kBloomBlock, BlockType::kFilter,
+ &bloom_block_contents);
+ bloom_in_file = s.ok() && bloom_block_contents.data.size() > 0;
+ }
+
+ Slice* bloom_block;
+ if (bloom_in_file) {
+ // If bloom_block_contents.allocation is not empty (which will be the case
+ // for non-mmap mode), it holds the alloated memory for the bloom block.
+ // It needs to be kept alive to keep `bloom_block` valid.
+ bloom_block_alloc_ = std::move(bloom_block_contents.allocation);
+ bloom_block = &bloom_block_contents.data;
+ } else {
+ bloom_block = nullptr;
+ }
+
+ Slice* index_block;
+ if (index_in_file) {
+ // If index_block_contents.allocation is not empty (which will be the case
+ // for non-mmap mode), it holds the alloated memory for the index block.
+ // It needs to be kept alive to keep `index_block` valid.
+ index_block_alloc_ = std::move(index_block_contents.allocation);
+ index_block = &index_block_contents.data;
+ } else {
+ index_block = nullptr;
+ }
+
+ if ((prefix_extractor_ == nullptr) && (hash_table_ratio != 0)) {
+ // moptions.prefix_extractor is requried for a hash-based look-up.
+ return Status::NotSupported(
+ "PlainTable requires a prefix extractor enable prefix hash mode.");
+ }
+
+ // First, read the whole file, for every kIndexIntervalForSamePrefixKeys 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.
+
+ if (!index_in_file) {
+ // Allocate bloom filter here for total order mode.
+ if (IsTotalOrderMode()) {
+ AllocateBloom(bloom_bits_per_key,
+ static_cast<uint32_t>(props->num_entries),
+ huge_page_tlb_size);
+ }
+ } else if (bloom_in_file) {
+ enable_bloom_ = true;
+ auto num_blocks_property = props->user_collected_properties.find(
+ PlainTablePropertyNames::kNumBloomBlocks);
+
+ uint32_t num_blocks = 0;
+ if (num_blocks_property != props->user_collected_properties.end()) {
+ Slice temp_slice(num_blocks_property->second);
+ if (!GetVarint32(&temp_slice, &num_blocks)) {
+ num_blocks = 0;
+ }
+ }
+ // cast away const qualifier, because bloom_ won't be changed
+ bloom_.SetRawData(const_cast<char*>(bloom_block->data()),
+ static_cast<uint32_t>(bloom_block->size()) * 8,
+ num_blocks);
+ } else {
+ // Index in file but no bloom in file. Disable bloom filter in this case.
+ enable_bloom_ = false;
+ bloom_bits_per_key = 0;
+ }
+
+ PlainTableIndexBuilder index_builder(&arena_, ioptions_, prefix_extractor_,
+ index_sparseness, hash_table_ratio,
+ huge_page_tlb_size);
+
+ std::vector<uint32_t> prefix_hashes;
+ if (!index_in_file) {
+ // Populates _bloom if enabled (total order mode)
+ s = PopulateIndexRecordList(&index_builder, &prefix_hashes);
+ if (!s.ok()) {
+ return s;
+ }
+ } else {
+ s = index_.InitFromRawData(*index_block);
+ if (!s.ok()) {
+ return s;
+ }
+ }
+
+ if (!index_in_file) {
+ if (!IsTotalOrderMode()) {
+ // Calculated bloom filter size and allocate memory for
+ // bloom filter based on the number of prefixes, then fill it.
+ AllocateBloom(bloom_bits_per_key, index_.GetNumPrefixes(),
+ huge_page_tlb_size);
+ if (enable_bloom_) {
+ FillBloom(prefix_hashes);
+ }
+ }
+ }
+
+ // Fill two table properties.
+ if (!index_in_file) {
+ props->user_collected_properties["plain_table_hash_table_size"] =
+ std::to_string(index_.GetIndexSize() * PlainTableIndex::kOffsetLen);
+ props->user_collected_properties["plain_table_sub_index_size"] =
+ std::to_string(index_.GetSubIndexSize());
+ } else {
+ props->user_collected_properties["plain_table_hash_table_size"] =
+ std::to_string(0);
+ props->user_collected_properties["plain_table_sub_index_size"] =
+ std::to_string(0);
+ }
+
+ return Status::OK();
+}
+
+Status PlainTableReader::GetOffset(PlainTableKeyDecoder* decoder,
+ const Slice& target, const Slice& prefix,
+ uint32_t prefix_hash, bool& prefix_matched,
+ uint32_t* offset) const {
+ prefix_matched = false;
+ uint32_t prefix_index_offset;
+ auto res = index_.GetOffset(prefix_hash, &prefix_index_offset);
+ if (res == PlainTableIndex::kNoPrefixForBucket) {
+ *offset = file_info_.data_end_offset;
+ return Status::OK();
+ } else if (res == PlainTableIndex::kDirectToFile) {
+ *offset = prefix_index_offset;
+ return Status::OK();
+ }
+
+ // point to sub-index, need to do a binary search
+ uint32_t upper_bound = 0;
+ const char* base_ptr =
+ index_.GetSubIndexBasePtrAndUpperBound(prefix_index_offset, &upper_bound);
+ uint32_t low = 0;
+ uint32_t high = upper_bound;
+ ParsedInternalKey mid_key;
+ ParsedInternalKey parsed_target;
+ Status s = ParseInternalKey(target, &parsed_target,
+ false /* log_err_key */); // TODO
+ if (!s.ok()) return s;
+
+ // The key is between [low, high). Do a binary search between it.
+ while (high - low > 1) {
+ uint32_t mid = (high + low) / 2;
+ uint32_t file_offset = GetFixed32Element(base_ptr, mid);
+ uint32_t tmp;
+ s = decoder->NextKeyNoValue(file_offset, &mid_key, nullptr, &tmp);
+ if (!s.ok()) {
+ return s;
+ }
+ int cmp_result = internal_comparator_.Compare(mid_key, parsed_target);
+ if (cmp_result < 0) {
+ low = mid;
+ } else {
+ if (cmp_result == 0) {
+ // Happen to have found the exact key or target is smaller than the
+ // first key after base_offset.
+ prefix_matched = true;
+ *offset = file_offset;
+ return Status::OK();
+ } else {
+ high = mid;
+ }
+ }
+ }
+ // 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.
+ ParsedInternalKey low_key;
+ uint32_t tmp;
+ uint32_t low_key_offset = GetFixed32Element(base_ptr, low);
+ s = decoder->NextKeyNoValue(low_key_offset, &low_key, nullptr, &tmp);
+ if (!s.ok()) {
+ return s;
+ }
+
+ if (GetPrefix(low_key) == prefix) {
+ prefix_matched = true;
+ *offset = low_key_offset;
+ } else if (low + 1 < upper_bound) {
+ // There is possible a next prefix, return it
+ prefix_matched = false;
+ *offset = GetFixed32Element(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.
+ *offset = file_info_.data_end_offset;
+ }
+ return Status::OK();
+}
+
+bool PlainTableReader::MatchBloom(uint32_t hash) const {
+ if (!enable_bloom_) {
+ return true;
+ }
+
+ if (bloom_.MayContainHash(hash)) {
+ PERF_COUNTER_ADD(bloom_sst_hit_count, 1);
+ return true;
+ } else {
+ PERF_COUNTER_ADD(bloom_sst_miss_count, 1);
+ return false;
+ }
+}
+
+Status PlainTableReader::Next(PlainTableKeyDecoder* decoder, uint32_t* offset,
+ ParsedInternalKey* parsed_key,
+ Slice* internal_key, Slice* value,
+ bool* seekable) const {
+ if (*offset == file_info_.data_end_offset) {
+ *offset = file_info_.data_end_offset;
+ return Status::OK();
+ }
+
+ if (*offset > file_info_.data_end_offset) {
+ return Status::Corruption("Offset is out of file size");
+ }
+
+ uint32_t bytes_read;
+ Status s = decoder->NextKey(*offset, parsed_key, internal_key, value,
+ &bytes_read, seekable);
+ if (!s.ok()) {
+ return s;
+ }
+ *offset = *offset + bytes_read;
+ return Status::OK();
+}
+
+void PlainTableReader::Prepare(const Slice& target) {
+ if (enable_bloom_) {
+ uint32_t prefix_hash = GetSliceHash(GetPrefix(target));
+ bloom_.Prefetch(prefix_hash);
+ }
+}
+
+Status PlainTableReader::Get(const ReadOptions& /*ro*/, const Slice& target,
+ GetContext* get_context,
+ const SliceTransform* /* prefix_extractor */,
+ bool /*skip_filters*/) {
+ // Check bloom filter first.
+ Slice prefix_slice;
+ uint32_t prefix_hash;
+ if (IsTotalOrderMode()) {
+ if (full_scan_mode_) {
+ status_ =
+ Status::InvalidArgument("Get() is not allowed in full scan mode.");
+ }
+ // Match whole user key for bloom filter check.
+ if (!MatchBloom(GetSliceHash(ExtractUserKey(target)))) {
+ return Status::OK();
+ }
+ // in total order mode, there is only one bucket 0, and we always use empty
+ // prefix.
+ prefix_slice = Slice();
+ prefix_hash = 0;
+ } else {
+ prefix_slice = GetPrefix(target);
+ prefix_hash = GetSliceHash(prefix_slice);
+ if (!MatchBloom(prefix_hash)) {
+ return Status::OK();
+ }
+ }
+ uint32_t offset;
+ bool prefix_match;
+ PlainTableKeyDecoder decoder(&file_info_, encoding_type_, user_key_len_,
+ prefix_extractor_);
+ Status s = GetOffset(&decoder, target, prefix_slice, prefix_hash,
+ prefix_match, &offset);
+
+ if (!s.ok()) {
+ return s;
+ }
+ ParsedInternalKey found_key;
+ ParsedInternalKey parsed_target;
+ s = ParseInternalKey(target, &parsed_target,
+ false /* log_err_key */); // TODO
+ if (!s.ok()) return s;
+
+ Slice found_value;
+ while (offset < file_info_.data_end_offset) {
+ s = Next(&decoder, &offset, &found_key, nullptr, &found_value);
+ if (!s.ok()) {
+ return s;
+ }
+ if (!prefix_match) {
+ // Need to verify prefix for the first key found if it is not yet
+ // checked.
+ if (GetPrefix(found_key) != prefix_slice) {
+ return Status::OK();
+ }
+ prefix_match = true;
+ }
+ // TODO(ljin): since we know the key comparison result here,
+ // can we enable the fast path?
+ if (internal_comparator_.Compare(found_key, parsed_target) >= 0) {
+ bool dont_care __attribute__((__unused__));
+ if (!get_context->SaveValue(found_key, found_value, &dont_care,
+ dummy_cleanable_.get())) {
+ break;
+ }
+ }
+ }
+ return Status::OK();
+}
+
+uint64_t PlainTableReader::ApproximateOffsetOf(const Slice& /*key*/,
+ TableReaderCaller /*caller*/) {
+ return 0;
+}
+
+uint64_t PlainTableReader::ApproximateSize(const Slice& /*start*/,
+ const Slice& /*end*/,
+ TableReaderCaller /*caller*/) {
+ return 0;
+}
+
+PlainTableIterator::PlainTableIterator(PlainTableReader* table,
+ bool use_prefix_seek)
+ : table_(table),
+ decoder_(&table_->file_info_, table_->encoding_type_,
+ table_->user_key_len_, table_->prefix_extractor_),
+ use_prefix_seek_(use_prefix_seek) {
+ next_offset_ = offset_ = table_->file_info_.data_end_offset;
+}
+
+PlainTableIterator::~PlainTableIterator() {}
+
+bool PlainTableIterator::Valid() const {
+ return offset_ < table_->file_info_.data_end_offset &&
+ offset_ >= table_->data_start_offset_;
+}
+
+void PlainTableIterator::SeekToFirst() {
+ status_ = Status::OK();
+ next_offset_ = table_->data_start_offset_;
+ if (next_offset_ >= table_->file_info_.data_end_offset) {
+ next_offset_ = offset_ = table_->file_info_.data_end_offset;
+ } else {
+ Next();
+ }
+}
+
+void PlainTableIterator::SeekToLast() {
+ assert(false);
+ status_ = Status::NotSupported("SeekToLast() is not supported in PlainTable");
+ next_offset_ = offset_ = table_->file_info_.data_end_offset;
+}
+
+void PlainTableIterator::Seek(const Slice& target) {
+ if (use_prefix_seek_ != !table_->IsTotalOrderMode()) {
+ // This check is done here instead of NewIterator() to permit creating an
+ // iterator with total_order_seek = true even if we won't be able to Seek()
+ // it. This is needed for compaction: it creates iterator with
+ // total_order_seek = true but usually never does Seek() on it,
+ // only SeekToFirst().
+ status_ = Status::InvalidArgument(
+ "total_order_seek not implemented for PlainTable.");
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ return;
+ }
+
+ // If the user doesn't set prefix seek option and we are not able to do a
+ // total Seek(). assert failure.
+ if (table_->IsTotalOrderMode()) {
+ if (table_->full_scan_mode_) {
+ status_ =
+ Status::InvalidArgument("Seek() is not allowed in full scan mode.");
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ return;
+ } else if (table_->GetIndexSize() > 1) {
+ assert(false);
+ status_ = Status::NotSupported(
+ "PlainTable cannot issue non-prefix seek unless in total order "
+ "mode.");
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ return;
+ }
+ }
+
+ Slice prefix_slice = table_->GetPrefix(target);
+ uint32_t prefix_hash = 0;
+ // Bloom filter is ignored in total-order mode.
+ if (!table_->IsTotalOrderMode()) {
+ prefix_hash = GetSliceHash(prefix_slice);
+ if (!table_->MatchBloom(prefix_hash)) {
+ status_ = Status::OK();
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ return;
+ }
+ }
+ bool prefix_match;
+ status_ = table_->GetOffset(&decoder_, target, prefix_slice, prefix_hash,
+ prefix_match, &next_offset_);
+ if (!status_.ok()) {
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ return;
+ }
+
+ if (next_offset_ < table_->file_info_.data_end_offset) {
+ for (Next(); status_.ok() && Valid(); Next()) {
+ if (!prefix_match) {
+ // Need to verify the first key's prefix
+ if (table_->GetPrefix(key()) != prefix_slice) {
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ break;
+ }
+ prefix_match = true;
+ }
+ if (table_->internal_comparator_.Compare(key(), target) >= 0) {
+ break;
+ }
+ }
+ } else {
+ offset_ = table_->file_info_.data_end_offset;
+ }
+}
+
+void PlainTableIterator::SeekForPrev(const Slice& /*target*/) {
+ assert(false);
+ status_ =
+ Status::NotSupported("SeekForPrev() is not supported in PlainTable");
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+}
+
+void PlainTableIterator::Next() {
+ offset_ = next_offset_;
+ if (offset_ < table_->file_info_.data_end_offset) {
+ Slice tmp_slice;
+ ParsedInternalKey parsed_key;
+ status_ =
+ table_->Next(&decoder_, &next_offset_, &parsed_key, &key_, &value_);
+ if (!status_.ok()) {
+ offset_ = next_offset_ = table_->file_info_.data_end_offset;
+ }
+ }
+}
+
+void PlainTableIterator::Prev() { assert(false); }
+
+Slice PlainTableIterator::key() const {
+ assert(Valid());
+ return key_;
+}
+
+Slice PlainTableIterator::value() const {
+ assert(Valid());
+ return value_;
+}
+
+Status PlainTableIterator::status() const { return status_; }
+
+} // namespace ROCKSDB_NAMESPACE
+#endif // ROCKSDB_LITE