ocaml/otherlibs/dbm/cldbm.c

167 lines
4.3 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Francois Rouaix, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../../LICENSE. */
/* */
/***********************************************************************/
/* $Id$ */
#include <string.h>
#include <fcntl.h>
#include <mlvalues.h>
#include <alloc.h>
#include <memory.h>
#include <fail.h>
#include <callback.h>
#ifdef DBM_USES_GDBM_NDBM
#include <gdbm-ndbm.h>
#else
#include <ndbm.h>
#endif
/* Quite close to sys_open_flags, but we need RDWR */
static int dbm_open_flags[] = {
O_RDONLY, O_WRONLY, O_RDWR, O_CREAT
};
static void raise_dbm (char *errmsg) Noreturn;
static void raise_dbm(char *errmsg)
{
static value * dbm_exn = NULL;
if (dbm_exn == NULL)
dbm_exn = caml_named_value("dbmerror");
raise_with_string(*dbm_exn, errmsg);
}
#define DBM_val(v) *((DBM **) &Field(v, 0))
static value alloc_dbm(DBM * db)
{
value res = alloc_small(1, Abstract_tag);
DBM_val(res) = db;
return res;
}
static DBM * extract_dbm(value vdb)
{
if (DBM_val(vdb) == NULL) raise_dbm("DBM has been closed");
return DBM_val(vdb);
}
/* Dbm.open : string -> Sys.open_flag list -> int -> t */
value caml_dbm_open(value vfile, value vflags, value vmode) /* ML */
{
char *file = String_val(vfile);
int flags = convert_flag_list(vflags, dbm_open_flags);
int mode = Int_val(vmode);
DBM *db = dbm_open(file,flags,mode);
if (db == NULL)
raise_dbm("Can't open file");
else
return (alloc_dbm(db));
}
/* Dbm.close: t -> unit */
value caml_dbm_close(value vdb) /* ML */
{
dbm_close(extract_dbm(vdb));
DBM_val(vdb) = NULL;
return Val_unit;
}
/* Dbm.fetch: t -> string -> string */
value caml_dbm_fetch(value vdb, value vkey) /* ML */
{
datum key,answer;
key.dptr = String_val(vkey);
key.dsize = string_length(vkey);
answer = dbm_fetch(extract_dbm(vdb), key);
if (answer.dptr) {
value res = alloc_string(answer.dsize);
memmove (String_val (res), answer.dptr, answer.dsize);
return res;
}
else raise_not_found();
}
value caml_dbm_insert(value vdb, value vkey, value vcontent) /* ML */
{
datum key, content;
key.dptr = String_val(vkey);
key.dsize = string_length(vkey);
content.dptr = String_val(vcontent);
content.dsize = string_length(vcontent);
switch(dbm_store(extract_dbm(vdb), key, content, DBM_INSERT)) {
case 0:
return Val_unit;
case 1: /* DBM_INSERT and already existing */
raise_dbm("Entry already exists");
default:
raise_dbm("dbm_store failed");
}
}
value caml_dbm_replace(value vdb, value vkey, value vcontent) /* ML */
{
datum key, content;
key.dptr = String_val(vkey);
key.dsize = string_length(vkey);
content.dptr = String_val(vcontent);
content.dsize = string_length(vcontent);
switch(dbm_store(extract_dbm(vdb), key, content, DBM_REPLACE)) {
case 0:
return Val_unit;
default:
raise_dbm("dbm_store failed");
}
}
value caml_dbm_delete(value vdb, value vkey) /* ML */
{
datum key;
key.dptr = String_val(vkey);
key.dsize = string_length(vkey);
if (dbm_delete(extract_dbm(vdb), key) < 0)
raise_dbm("dbm_delete");
else return Val_unit;
}
value caml_dbm_firstkey(value vdb) /* ML */
{
datum key = dbm_firstkey(extract_dbm(vdb));
if (key.dptr) {
value res = alloc_string(key.dsize);
memmove (String_val (res), key.dptr, key.dsize);
return res;
}
else raise_not_found();
}
value caml_dbm_nextkey(value vdb) /* ML */
{
datum key = dbm_nextkey(extract_dbm(vdb));
if (key.dptr) {
value res = alloc_string(key.dsize);
memmove (String_val (res), key.dptr, key.dsize);
return res;
}
else raise_not_found();
}