您最多选择25个主题
主题必须以字母或数字开头，可以包含连字符 (-)，并且长度不得超过35个字符
285 行
9.5 KiB
285 行
9.5 KiB
/* 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.
|
|
|
|
C bindings for leveldb. May be useful as a stable ABI that can be
|
|
used by programs that keep leveldb in a shared library, or for
|
|
a JNI api.
|
|
|
|
Does not support:
|
|
. getters for the option types
|
|
. custom comparators that implement key shortening
|
|
. capturing post-write-snapshot
|
|
. custom iter, db, env, cache implementations using just the C bindings
|
|
|
|
Some conventions:
|
|
|
|
(1) We expose just opaque struct pointers and functions to clients.
|
|
This allows us to change internal representations without having to
|
|
recompile clients.
|
|
|
|
(2) For simplicity, there is no equivalent to the Slice type. Instead,
|
|
the caller has to pass the pointer and length as separate
|
|
arguments.
|
|
|
|
(3) Errors are represented by a null-terminated c string. NULL
|
|
means no error. All operations that can raise an error are passed
|
|
a "char** errptr" as the last argument. One of the following must
|
|
be true on entry:
|
|
*errptr == NULL
|
|
*errptr points to a malloc()ed null-terminated error message
|
|
(On Windows, *errptr must have been malloc()-ed by this library.)
|
|
On success, a leveldb routine leaves *errptr unchanged.
|
|
On failure, leveldb frees the old value of *errptr and
|
|
set *errptr to a malloc()ed error message.
|
|
|
|
(4) Bools have the type unsigned char (0 == false; rest == true)
|
|
|
|
(5) All of the pointer arguments must be non-NULL.
|
|
*/
|
|
|
|
#ifndef STORAGE_LEVELDB_INCLUDE_C_H_
|
|
#define STORAGE_LEVELDB_INCLUDE_C_H_
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#include <stdarg.h>
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
/* Exported types */
|
|
|
|
typedef struct leveldb_t leveldb_t;
|
|
typedef struct leveldb_cache_t leveldb_cache_t;
|
|
typedef struct leveldb_comparator_t leveldb_comparator_t;
|
|
typedef struct leveldb_env_t leveldb_env_t;
|
|
typedef struct leveldb_filelock_t leveldb_filelock_t;
|
|
typedef struct leveldb_filterpolicy_t leveldb_filterpolicy_t;
|
|
typedef struct leveldb_iterator_t leveldb_iterator_t;
|
|
typedef struct leveldb_logger_t leveldb_logger_t;
|
|
typedef struct leveldb_options_t leveldb_options_t;
|
|
typedef struct leveldb_randomfile_t leveldb_randomfile_t;
|
|
typedef struct leveldb_readoptions_t leveldb_readoptions_t;
|
|
typedef struct leveldb_seqfile_t leveldb_seqfile_t;
|
|
typedef struct leveldb_snapshot_t leveldb_snapshot_t;
|
|
typedef struct leveldb_writablefile_t leveldb_writablefile_t;
|
|
typedef struct leveldb_writebatch_t leveldb_writebatch_t;
|
|
typedef struct leveldb_writeoptions_t leveldb_writeoptions_t;
|
|
|
|
/* DB operations */
|
|
|
|
extern leveldb_t* leveldb_open(
|
|
const leveldb_options_t* options,
|
|
const char* name,
|
|
char** errptr);
|
|
|
|
extern void leveldb_close(leveldb_t* db);
|
|
|
|
extern void leveldb_put(
|
|
leveldb_t* db,
|
|
const leveldb_writeoptions_t* options,
|
|
const char* key, size_t keylen,
|
|
const char* val, size_t vallen,
|
|
char** errptr);
|
|
|
|
extern void leveldb_delete(
|
|
leveldb_t* db,
|
|
const leveldb_writeoptions_t* options,
|
|
const char* key, size_t keylen,
|
|
char** errptr);
|
|
|
|
extern void leveldb_write(
|
|
leveldb_t* db,
|
|
const leveldb_writeoptions_t* options,
|
|
leveldb_writebatch_t* batch,
|
|
char** errptr);
|
|
|
|
/* Returns NULL if not found. A malloc()ed array otherwise.
|
|
Stores the length of the array in *vallen. */
|
|
extern char* leveldb_get(
|
|
leveldb_t* db,
|
|
const leveldb_readoptions_t* options,
|
|
const char* key, size_t keylen,
|
|
size_t* vallen,
|
|
char** errptr);
|
|
|
|
extern leveldb_iterator_t* leveldb_create_iterator(
|
|
leveldb_t* db,
|
|
const leveldb_readoptions_t* options);
|
|
|
|
extern const leveldb_snapshot_t* leveldb_create_snapshot(
|
|
leveldb_t* db);
|
|
|
|
extern void leveldb_release_snapshot(
|
|
leveldb_t* db,
|
|
const leveldb_snapshot_t* snapshot);
|
|
|
|
/* Returns NULL if property name is unknown.
|
|
Else returns a pointer to a malloc()-ed null-terminated value. */
|
|
extern char* leveldb_property_value(
|
|
leveldb_t* db,
|
|
const char* propname);
|
|
|
|
extern void leveldb_approximate_sizes(
|
|
leveldb_t* db,
|
|
int num_ranges,
|
|
const char* const* range_start_key, const size_t* range_start_key_len,
|
|
const char* const* range_limit_key, const size_t* range_limit_key_len,
|
|
uint64_t* sizes);
|
|
|
|
extern void leveldb_compact_range(
|
|
leveldb_t* db,
|
|
const char* start_key, size_t start_key_len,
|
|
const char* limit_key, size_t limit_key_len);
|
|
|
|
/* Management operations */
|
|
|
|
extern void leveldb_destroy_db(
|
|
const leveldb_options_t* options,
|
|
const char* name,
|
|
char** errptr);
|
|
|
|
extern void leveldb_repair_db(
|
|
const leveldb_options_t* options,
|
|
const char* name,
|
|
char** errptr);
|
|
|
|
/* Iterator */
|
|
|
|
extern void leveldb_iter_destroy(leveldb_iterator_t*);
|
|
extern unsigned char leveldb_iter_valid(const leveldb_iterator_t*);
|
|
extern void leveldb_iter_seek_to_first(leveldb_iterator_t*);
|
|
extern void leveldb_iter_seek_to_last(leveldb_iterator_t*);
|
|
extern void leveldb_iter_seek(leveldb_iterator_t*, const char* k, size_t klen);
|
|
extern void leveldb_iter_next(leveldb_iterator_t*);
|
|
extern void leveldb_iter_prev(leveldb_iterator_t*);
|
|
extern const char* leveldb_iter_key(const leveldb_iterator_t*, size_t* klen);
|
|
extern const char* leveldb_iter_value(const leveldb_iterator_t*, size_t* vlen);
|
|
extern void leveldb_iter_get_error(const leveldb_iterator_t*, char** errptr);
|
|
|
|
/* Write batch */
|
|
|
|
extern leveldb_writebatch_t* leveldb_writebatch_create();
|
|
extern void leveldb_writebatch_destroy(leveldb_writebatch_t*);
|
|
extern void leveldb_writebatch_clear(leveldb_writebatch_t*);
|
|
extern void leveldb_writebatch_put(
|
|
leveldb_writebatch_t*,
|
|
const char* key, size_t klen,
|
|
const char* val, size_t vlen);
|
|
extern void leveldb_writebatch_delete(
|
|
leveldb_writebatch_t*,
|
|
const char* key, size_t klen);
|
|
extern void leveldb_writebatch_iterate(
|
|
leveldb_writebatch_t*,
|
|
void* state,
|
|
void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
|
|
void (*deleted)(void*, const char* k, size_t klen));
|
|
|
|
/* Options */
|
|
|
|
extern leveldb_options_t* leveldb_options_create();
|
|
extern void leveldb_options_destroy(leveldb_options_t*);
|
|
extern void leveldb_options_set_comparator(
|
|
leveldb_options_t*,
|
|
leveldb_comparator_t*);
|
|
extern void leveldb_options_set_filter_policy(
|
|
leveldb_options_t*,
|
|
leveldb_filterpolicy_t*);
|
|
extern void leveldb_options_set_create_if_missing(
|
|
leveldb_options_t*, unsigned char);
|
|
extern void leveldb_options_set_error_if_exists(
|
|
leveldb_options_t*, unsigned char);
|
|
extern void leveldb_options_set_paranoid_checks(
|
|
leveldb_options_t*, unsigned char);
|
|
extern void leveldb_options_set_env(leveldb_options_t*, leveldb_env_t*);
|
|
extern void leveldb_options_set_info_log(leveldb_options_t*, leveldb_logger_t*);
|
|
extern void leveldb_options_set_write_buffer_size(leveldb_options_t*, size_t);
|
|
extern void leveldb_options_set_max_open_files(leveldb_options_t*, int);
|
|
extern void leveldb_options_set_cache(leveldb_options_t*, leveldb_cache_t*);
|
|
extern void leveldb_options_set_block_size(leveldb_options_t*, size_t);
|
|
extern void leveldb_options_set_block_restart_interval(leveldb_options_t*, int);
|
|
|
|
enum {
|
|
leveldb_no_compression = 0,
|
|
leveldb_snappy_compression = 1
|
|
};
|
|
extern void leveldb_options_set_compression(leveldb_options_t*, int);
|
|
|
|
/* Comparator */
|
|
|
|
extern leveldb_comparator_t* leveldb_comparator_create(
|
|
void* state,
|
|
void (*destructor)(void*),
|
|
int (*compare)(
|
|
void*,
|
|
const char* a, size_t alen,
|
|
const char* b, size_t blen),
|
|
const char* (*name)(void*));
|
|
extern void leveldb_comparator_destroy(leveldb_comparator_t*);
|
|
|
|
/* Filter policy */
|
|
|
|
extern leveldb_filterpolicy_t* leveldb_filterpolicy_create(
|
|
void* state,
|
|
void (*destructor)(void*),
|
|
char* (*create_filter)(
|
|
void*,
|
|
const char* const* key_array, const size_t* key_length_array,
|
|
int num_keys,
|
|
size_t* filter_length),
|
|
unsigned char (*key_may_match)(
|
|
void*,
|
|
const char* key, size_t length,
|
|
const char* filter, size_t filter_length),
|
|
const char* (*name)(void*));
|
|
extern void leveldb_filterpolicy_destroy(leveldb_filterpolicy_t*);
|
|
|
|
extern leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(
|
|
int bits_per_key);
|
|
|
|
/* Read options */
|
|
|
|
extern leveldb_readoptions_t* leveldb_readoptions_create();
|
|
extern void leveldb_readoptions_destroy(leveldb_readoptions_t*);
|
|
extern void leveldb_readoptions_set_verify_checksums(
|
|
leveldb_readoptions_t*,
|
|
unsigned char);
|
|
extern void leveldb_readoptions_set_fill_cache(
|
|
leveldb_readoptions_t*, unsigned char);
|
|
extern void leveldb_readoptions_set_snapshot(
|
|
leveldb_readoptions_t*,
|
|
const leveldb_snapshot_t*);
|
|
|
|
/* Write options */
|
|
|
|
extern leveldb_writeoptions_t* leveldb_writeoptions_create();
|
|
extern void leveldb_writeoptions_destroy(leveldb_writeoptions_t*);
|
|
extern void leveldb_writeoptions_set_sync(
|
|
leveldb_writeoptions_t*, unsigned char);
|
|
|
|
/* Cache */
|
|
|
|
extern leveldb_cache_t* leveldb_cache_create_lru(size_t capacity);
|
|
extern void leveldb_cache_destroy(leveldb_cache_t* cache);
|
|
|
|
/* Env */
|
|
|
|
extern leveldb_env_t* leveldb_create_default_env();
|
|
extern void leveldb_env_destroy(leveldb_env_t*);
|
|
|
|
/* Utility */
|
|
|
|
/* Calls free(ptr).
|
|
REQUIRES: ptr was malloc()-ed and returned by one of the routines
|
|
in this file. Note that in certain cases (typically on Windows), you
|
|
may need to call this routine instead of free(ptr) to dispose of
|
|
malloc()-ed memory returned by this library. */
|
|
extern void leveldb_free(void* ptr);
|
|
|
|
#ifdef __cplusplus
|
|
} /* end extern "C" */
|
|
#endif
|
|
|
|
#endif /* STORAGE_LEVELDB_INCLUDE_C_H_ */
|