mirror of
https://github.com/facebook/rocksdb.git
synced 2024-11-30 13:41:46 +00:00
98 lines
3.8 KiB
C++
98 lines
3.8 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under the BSD-style license found in the
|
|
// LICENSE file in the root directory of this source tree. An additional grant
|
|
// of patent rights can be found in the PATENTS file in the same directory.
|
|
|
|
#pragma once
|
|
#ifndef ROCKSDB_LITE
|
|
|
|
#include "rocksdb/slice.h"
|
|
#include "db/dbformat.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
class WritableFile;
|
|
struct ParsedInternalKey;
|
|
|
|
// Helper class to write out a key to an output file
|
|
// Actual data format of the key is documented in plain_table_factory.h
|
|
class PlainTableKeyEncoder {
|
|
public:
|
|
explicit PlainTableKeyEncoder(EncodingType encoding_type,
|
|
uint32_t user_key_len,
|
|
const SliceTransform* prefix_extractor,
|
|
size_t index_sparseness)
|
|
: encoding_type_((prefix_extractor != nullptr) ? encoding_type : kPlain),
|
|
fixed_user_key_len_(user_key_len),
|
|
prefix_extractor_(prefix_extractor),
|
|
index_sparseness_((index_sparseness > 1) ? index_sparseness : 1),
|
|
key_count_for_prefix_(0) {}
|
|
// key: the key to write out, in the format of internal key.
|
|
// file: the output file to write out
|
|
// offset: offset in the file. Needs to be updated after appending bytes
|
|
// for the key
|
|
// meta_bytes_buf: buffer for extra meta bytes
|
|
// meta_bytes_buf_size: offset to append extra meta bytes. Will be updated
|
|
// if meta_bytes_buf is updated.
|
|
Status AppendKey(const Slice& key, WritableFile* file, uint64_t* offset,
|
|
char* meta_bytes_buf, size_t* meta_bytes_buf_size);
|
|
|
|
// Return actual encoding type to be picked
|
|
EncodingType GetEncodingType() { return encoding_type_; }
|
|
|
|
private:
|
|
EncodingType encoding_type_;
|
|
uint32_t fixed_user_key_len_;
|
|
const SliceTransform* prefix_extractor_;
|
|
const size_t index_sparseness_;
|
|
size_t key_count_for_prefix_;
|
|
IterKey pre_prefix_;
|
|
};
|
|
|
|
// A helper class to decode keys from input buffer
|
|
// Actual data format of the key is documented in plain_table_factory.h
|
|
class PlainTableKeyDecoder {
|
|
public:
|
|
explicit PlainTableKeyDecoder(EncodingType encoding_type,
|
|
uint32_t user_key_len,
|
|
const SliceTransform* prefix_extractor)
|
|
: encoding_type_(encoding_type),
|
|
prefix_len_(0),
|
|
fixed_user_key_len_(user_key_len),
|
|
prefix_extractor_(prefix_extractor),
|
|
in_prefix_(false) {}
|
|
// Find the next key.
|
|
// start: char array where the key starts.
|
|
// limit: boundary of the char array
|
|
// parsed_key: the output of the result key
|
|
// internal_key: if not null, fill with the output of the result key in
|
|
// un-parsed format
|
|
// bytes_read: how many bytes read from start. Output
|
|
// seekable: whether key can be read from this place. Used when building
|
|
// indexes. Output.
|
|
Status NextKey(const char* start, const char* limit,
|
|
ParsedInternalKey* parsed_key, Slice* internal_key,
|
|
size_t* bytes_read, bool* seekable = nullptr);
|
|
EncodingType encoding_type_;
|
|
uint32_t prefix_len_;
|
|
uint32_t fixed_user_key_len_;
|
|
Slice saved_user_key_;
|
|
IterKey cur_key_;
|
|
const SliceTransform* prefix_extractor_;
|
|
bool in_prefix_;
|
|
|
|
private:
|
|
Status NextPlainEncodingKey(const char* start, const char* limit,
|
|
ParsedInternalKey* parsed_key,
|
|
Slice* internal_key, size_t* bytes_read,
|
|
bool* seekable = nullptr);
|
|
Status NextPrefixEncodingKey(const char* start, const char* limit,
|
|
ParsedInternalKey* parsed_key,
|
|
Slice* internal_key, size_t* bytes_read,
|
|
bool* seekable = nullptr);
|
|
};
|
|
|
|
} // namespace rocksdb
|
|
|
|
#endif // ROCKSDB_LITE
|