You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
290 lines
9.6 KiB
290 lines
9.6 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 |
|
. 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); |
|
|
|
/* Return the major version number for this release. */ |
|
extern int leveldb_major_version(); |
|
|
|
/* Return the minor version number for this release. */ |
|
extern int leveldb_minor_version(); |
|
|
|
#ifdef __cplusplus |
|
} /* end extern "C" */ |
|
#endif |
|
|
|
#endif /* STORAGE_LEVELDB_INCLUDE_C_H_ */
|
|
|