/*
Trivial Database 2: traverse function.
Copyright (C) Rusty Russell 2010
This library 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 3 of the License, or (at your option) any later version.
This library 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 this library; if not, see .
*/
#include "private.h"
#include
static int64_t traverse(struct tdb_context *tdb, int ltype,
tdb_traverse_func fn, void *p)
{
int ret;
struct traverse_info tinfo;
struct tdb_data k, d;
int64_t count = 0;
for (ret = first_in_hash(tdb, ltype, &tinfo, &k, &d.dsize);
ret == 1;
ret = next_in_hash(tdb, ltype, &tinfo, &k, &d.dsize)) {
d.dptr = k.dptr + k.dsize;
count++;
if (fn && fn(tdb, k, d, p))
break;
}
if (ret < 0)
return -1;
return count;
}
int64_t tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *p)
{
return traverse(tdb, F_WRLCK, fn, p);
}
int64_t tdb_traverse_read(struct tdb_context *tdb,
tdb_traverse_func fn, void *p)
{
int64_t ret;
bool was_ro = tdb->read_only;
tdb->read_only = true;
ret = traverse(tdb, F_RDLCK, fn, p);
tdb->read_only = was_ro;
return ret;
}
TDB_DATA tdb_firstkey(struct tdb_context *tdb)
{
struct traverse_info tinfo;
struct tdb_data k;
switch (first_in_hash(tdb, F_RDLCK, &tinfo, &k, NULL)) {
case 1:
return k;
case 0:
tdb->ecode = TDB_SUCCESS;
/* Fall thru... */
default:
return tdb_null;
}
}
/* We lock twice, not very efficient. We could keep last key & tinfo cached. */
TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA key)
{
struct traverse_info tinfo;
struct hash_info h;
struct tdb_used_record rec;
tinfo.prev = find_and_lock(tdb, key, F_RDLCK, &h, &rec, &tinfo);
if (unlikely(tinfo.prev == TDB_OFF_ERR))
return tdb_null;
tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
switch (next_in_hash(tdb, F_RDLCK, &tinfo, &key, NULL)) {
case 1:
return key;
case 0:
tdb->ecode = TDB_SUCCESS;
/* Fall thru... */
default:
return tdb_null;
}
}