tcadb.h

Tokyo Cabinet的Tokyo Cabinet 是一个DBM的实现。这里的数据库由一系列key-value对的记录构成。key和value都可以是任意长度的字节序列,既可以是二进制也可以是字符

/*************************************************************************************************
 * The abstract database API of Tokyo Cabinet
 *                                                      Copyright (C) 2006-2009 Mikio Hirabayashi
 * This file is part of Tokyo Cabinet.
 * Tokyo Cabinet is free software; you can redistribute it and/or modify it under the terms of
 * the GNU Lesser General Public License as published by the Free Software Foundation; either
 * version 2.1 of the License or any later version.  Tokyo Cabinet is distributed in the hope
 * that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * You should have received a copy of the GNU Lesser General Public License along with Tokyo
 * Cabinet; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA.
 *************************************************************************************************/


#ifndef _TCADB_H                         /* duplication check */
#define _TCADB_H

#if defined(__cplusplus)
#define __TCADB_CLINKAGEBEGIN extern "C" {
#define __TCADB_CLINKAGEEND }
#else
#define __TCADB_CLINKAGEBEGIN
#define __TCADB_CLINKAGEEND
#endif
__TCADB_CLINKAGEBEGIN


#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <time.h>
#include <math.h>
#include <tcutil.h>
#include <tchdb.h>
#include <tcbdb.h>
#include <tcfdb.h>
#include <tctdb.h>



/*************************************************************************************************
 * API
 *************************************************************************************************/


typedef struct {                         /* type of structure for an abstract database */
  char *name;                            /* name of the database */
  int omode;                             /* open mode */
  TCMDB *mdb;                            /* on-memory hash database object */
  TCNDB *ndb;                            /* on-memory tree database object */
  TCHDB *hdb;                            /* hash database object */
  TCBDB *bdb;                            /* B+ tree database object */
  TCFDB *fdb;                            /* fixed-length databae object */
  TCTDB *tdb;                            /* table database object */
  int64_t capnum;                        /* capacity number of records */
  int64_t capsiz;                        /* capacity size of using memory */
  uint32_t capcnt;                       /* count for capacity check */
  BDBCUR *cur;                           /* cursor of B+ tree */
} TCADB;

enum {                                   /* enumeration for open modes */
  ADBOVOID,                              /* not opened */
  ADBOMDB,                               /* on-memory hash database */
  ADBONDB,                               /* on-memory tree database */
  ADBOHDB,                               /* hash database */
  ADBOBDB,                               /* B+ tree database */
  ADBOFDB,                               /* fixed-length database */
  ADBOTDB                                /* table database */
};


/* Create an abstract database object.
   The return value is the new abstract database object. */
TCADB *tcadbnew(void);


/* Delete an abstract database object.
   `adb' specifies the abstract database object. */
void tcadbdel(TCADB *adb);


/* Open an abstract database.
   `adb' specifies the abstract database object.
   `name' specifies the name of the database.  If it is "*", the database will be an on-memory
   hash database.  If it is "+", the database will be an on-memory tree database.  If its suffix
   is ".tch", the database will be a hash database.  If its suffix is ".tcb", the database will
   be a B+ tree database.  If its suffix is ".tcf", the database will be a fixed-length database.
   If its suffix is ".tct", the database will be a table database.  Otherwise, this function
   fails.  Tuning parameters can trail the name, separated by "#".  Each parameter is composed of
   the name and the value, separated by "=".  On-memory hash database supports "bnum", "capnum",
   and "capsiz".  On-memory tree database supports "capnum" and "capsiz".  Hash database supports
   "mode", "bnum", "apow", "fpow", "opts", "rcnum", and "xmsiz".  B+ tree database supports
   "mode", "lmemb", "nmemb", "bnum", "apow", "fpow", "opts", "lcnum", "ncnum", and "xmsiz".
   Fixed-length database supports "mode", "width", and "limsiz".  Table database supports "mode",
   "bnum", "apow", "fpow", "opts", "rcnum", "lcnum", "ncnum", "xmsiz", and "idx".
   If successful, the return value is true, else, it is false.
   The tuning parameter "capnum" specifies the capacity number of records.  "capsiz" specifies
   the capacity size of using memory.  Records spilled the capacity are removed by the storing
   order.  "mode" can contain "w" of writer, "r" of reader, "c" of creating, "t" of truncating,
   "e" of no locking, and "f" of non-blocking lock.  The default mode is relevant to "wc".
   "opts" can contains "l" of large option, "d" of Deflate option, "b" of BZIP2 option, and "t"
   of TCBS option.  "idx" specifies the column name of an index and its type separated by ":".
   For example, "casket.tch#bnum=1000000#opts=ld" means that the name of the database file is
   "casket.tch", and the bucket number is 1000000, and the options are large and Deflate. */
bool tcadbopen(TCADB *adb, const char *name);


/* Close an abstract database object.
   `adb' specifies the abstract database object.
   If successful, the return value is true, else, it is false.
   Update of a database is assured to be written when the database is closed.  If a writer opens
   a database but does not close it appropriately, the database will be broken. */
bool tcadbclose(TCADB *adb);


/* Store a record into an abstract database object.
   `adb' specifies the abstract database object.
   `kbuf' specifies the pointer to the region of the key.
   `ksiz' specifies the size of the region of the key.
   `vbuf' specifies the pointer to the region of the value.
   `vsiz' specifies the size of the region of the value.
   If successful, the return value is true, else, it is false.
   If a record with the same key exists in the database, it is overwritten. */
bool tcadbput(TCADB *adb, const void *kbuf, int ksiz, const void *vbuf, int vsiz);


/* Store a string record into an abstract object.
   `adb' specifies the abstract database object.
   `kstr' specifies the string of the key.
   `vstr' specifies the string of the value.
   If successful, the return value is true, else, it is false.
   If a record with the same key exists in the database, it is overwritten. */
bool tcadbput2(TCADB *adb, const char *kstr, const char *vstr);


/* Store a new record into an abstract database object.
   `adb' specifies the abstract database object.
   `kbuf' specifies the pointer to the region of the key.
   `ksiz' specifies the size of the region of the key.
   `vbuf' specifies the pointer to the region of the value.
   `vsiz' specifies the size of the region of the value.
   If successful, the return value is true, else, it is false.
   If a record with the same key exists in the database, this function has no effect. */
bool tcadbputkeep(TCADB *adb, const void *kbuf, int ksiz, const void *vbuf, int vsiz);


/* Store a new string record into an abstract database object.
   `adb' specifies the abstract database object.
   `kstr' specifies the string of the key.
   `vstr' specifies the string of the value.
   If successful, the return value is true, else, it is false.
   If a record with the same key exists in the database, this function has no effect. */
bool tcadbputkeep2(TCADB *adb, const char *kstr, const char *vstr);


/* Concatenate a value at the end of the existing record in an abstract database object.
   `adb' specifies the abstract database object.
   `kbuf' specifies the pointer to the region of the key.
   `ksiz' specifies the size of the region of the key.
   `vbuf' specifies the pointer to the region of the value.
   `vsiz' specifies the size of the region of the value.
   If successful, the return value is true, else, it is false.
   If there is no corresponding record, a new record is created. */
bool tcadbputcat(TCADB *adb, const void *kbuf, int ksiz, const void *vbuf, int vsiz);


/* Concatenate a string value at the end of the existing record in an abstract database object.
   `adb' specifies the abstract database object.
   `kstr' specifies the string of the key.
   `vstr' specifies the string of the value.
   If successful, the return value is true, else, it is false.
   If there is no corresponding record, a new record is created. */
bool tcadbputcat2(TCADB *adb, const char *kstr, const char *vstr);


/* Remove a record of an abstract database object.
   `adb' specifies the abstract database object.
   `kbuf' specifies the pointer to the region of the key.
   `ksiz' specifies the size of the region of the key.
   If successful, the return value is true, else, it is false. */
bool tcadbout(TCADB *adb, const void *kbuf, int ksiz);


/* Remove a string record of an abstract database object.
   `adb' specifies the abstract database object.
   `kstr' specifies the string of the key.
   If successful, the return value is true, else, it is false. */
bool tcadbout2(TCADB *adb, const char *kstr);


/* Retrieve a record in an abstract database object.
   `adb' specifies the abstract database object.
   `kbuf' specifies the pointer to the region of the key.
   `ksiz' specifies the size of the region of the key.
   `sp' specifies the pointer to the variable into which the size of the region of the return
   value is assigned.
   If successful, the return value is the pointer to the region of the value of the corresponding
   record.  `NULL' is returned if no record corresponds.
   Because an additional zero code is appended at the end of the region of the return value,
   the return value can be treated as a character string.  Because the region of the return
   value is allocated with the `malloc' call, it should be released with the `free' call when
   it is no longer in use. */
void *tcadbget(TCADB *adb, const void *kbuf, int ksiz, int *sp);


/* Retrieve a string record in an abstract database object.
   `adb' specifies the abstract database object.
   `kstr' specifies the string of the key.
   If successful, the return value is the string of the value of the corresponding record.
   `NULL' is returned if no record corresponds.
   Because the region of the return value is allocated with the `malloc' call, it should be
   released with the `free' call when it is no longer in use. */
char *tcadbget2(TCADB *adb, const char *kstr);


/* Get the size of the value of a record in an abstract database object.
   `adb' specifies the abstract database object.
   `kbuf' specifies the pointer to the region of the key.
   `ksiz' specifies the size of the region of the key.
   If successful, the return value is the size of the value of the corresponding record, else,
   it is -1. */
int tcadbvsiz(TCADB *adb, const void *kbuf, int ksiz);


/* Get the size of the value of a string record in an abstract database object.
   `adb' specifies the abstract database object.
   `kstr' specifies the string of the key.
   If successful, the return value is the size of the value of the corresponding record, else,
   it is -1. */
int tcadbvsiz2(TCADB *adb, const char *kstr);


/* Initialize the iterator of an abstract database object.
   `adb' specifies the abstract database object.
   If successful, the return value is true, else, it is false.
   The iterator is used in order to access the key of every record stored in a database. */
bool tcadbiterinit(TCADB *adb);


/* Get the next key of the iterator of an abstract database object.
   `adb' specifies the abstract database object.
   `sp' specifies the pointer to the variable into which the size of the region of the return
   value is assigned.
   If successful, the return value is the pointer to the region of the next key, else, it is
   `NULL'.  `NULL' is returned when no record is to be get out of the iterator.
   Because an additional zero code is appended at the end of the region of the return value, the
   return value can be treated as a character string.  Because the region of the return value is
   allocated with the `malloc' call, it should be released with the `free' call when it is no
   longer in use.  It is possible to access every record by iteration of calling this function.
   It is allowed to update or remove records whose keys are fetched while the iteration.
   However, it is not assured if updating the database is occurred while the iteration.  Besides,