glibc/db/recno/rec_get.c

312 lines
7.2 KiB
C

/*-
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rec_get.c 8.9 (Berkeley) 8/18/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <db.h>
#include "recno.h"
/*
* __REC_GET -- Get a record from the btree.
*
* Parameters:
* dbp: pointer to access method
* key: key to find
* data: data to return
* flag: currently unused
*
* Returns:
* RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
*/
int
__rec_get(dbp, key, data, flags)
const DB *dbp;
const DBT *key;
DBT *data;
u_int flags;
{
BTREE *t;
EPG *e;
recno_t nrec;
int status;
t = dbp->internal;
/* Toss any page pinned across calls. */
if (t->bt_pinned != NULL) {
mpool_put(t->bt_mp, t->bt_pinned, 0);
t->bt_pinned = NULL;
}
/* Get currently doesn't take any flags, and keys of 0 are illegal. */
if (flags || (nrec = *(recno_t *)key->data) == 0) {
errno = EINVAL;
return (RET_ERROR);
}
/*
* If we haven't seen this record yet, try to find it in the
* original file.
*/
if (nrec > t->bt_nrecs) {
if (F_ISSET(t, R_EOF | R_INMEM))
return (RET_SPECIAL);
if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
return (status);
}
--nrec;
if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
return (RET_ERROR);
status = __rec_ret(t, e, 0, NULL, data);
if (F_ISSET(t, B_DB_LOCK))
mpool_put(t->bt_mp, e->page, 0);
else
t->bt_pinned = e->page;
return (status);
}
/*
* __REC_FPIPE -- Get fixed length records from a pipe.
*
* Parameters:
* t: tree
* cnt: records to read
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__rec_fpipe(t, top)
BTREE *t;
recno_t top;
{
DBT data;
recno_t nrec;
size_t len;
int ch;
u_char *p;
if (t->bt_rdata.size < t->bt_reclen) {
t->bt_rdata.data = t->bt_rdata.data == NULL ?
malloc(t->bt_reclen) :
realloc(t->bt_rdata.data, t->bt_reclen);
if (t->bt_rdata.data == NULL)
return (RET_ERROR);
t->bt_rdata.size = t->bt_reclen;
}
data.data = t->bt_rdata.data;
data.size = t->bt_reclen;
for (nrec = t->bt_nrecs; nrec < top;) {
len = t->bt_reclen;
for (p = t->bt_rdata.data;; *p++ = ch)
if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
if (ch != EOF)
*p = ch;
if (len != 0)
memset(p, t->bt_bval, len);
if (__rec_iput(t,
nrec, &data, 0) != RET_SUCCESS)
return (RET_ERROR);
++nrec;
break;
}
if (ch == EOF)
break;
}
if (nrec < top) {
F_SET(t, R_EOF);
return (RET_SPECIAL);
}
return (RET_SUCCESS);
}
/*
* __REC_VPIPE -- Get variable length records from a pipe.
*
* Parameters:
* t: tree
* cnt: records to read
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__rec_vpipe(t, top)
BTREE *t;
recno_t top;
{
DBT data;
recno_t nrec;
indx_t len;
size_t sz;
int bval, ch;
u_char *p;
bval = t->bt_bval;
for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
for (p = t->bt_rdata.data,
sz = t->bt_rdata.size;; *p++ = ch, --sz) {
if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
data.data = t->bt_rdata.data;
data.size = p - (u_char *)t->bt_rdata.data;
if (ch == EOF && data.size == 0)
break;
if (__rec_iput(t, nrec, &data, 0)
!= RET_SUCCESS)
return (RET_ERROR);
break;
}
if (sz == 0) {
len = p - (u_char *)t->bt_rdata.data;
t->bt_rdata.size += (sz = 256);
t->bt_rdata.data = t->bt_rdata.data == NULL ?
malloc(t->bt_rdata.size) :
realloc(t->bt_rdata.data, t->bt_rdata.size);
if (t->bt_rdata.data == NULL)
return (RET_ERROR);
p = (u_char *)t->bt_rdata.data + len;
}
}
if (ch == EOF)
break;
}
if (nrec < top) {
F_SET(t, R_EOF);
return (RET_SPECIAL);
}
return (RET_SUCCESS);
}
/*
* __REC_FMAP -- Get fixed length records from a file.
*
* Parameters:
* t: tree
* cnt: records to read
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__rec_fmap(t, top)
BTREE *t;
recno_t top;
{
DBT data;
recno_t nrec;
u_char *sp, *ep, *p;
size_t len;
if (t->bt_rdata.size < t->bt_reclen) {
t->bt_rdata.data = t->bt_rdata.data == NULL ?
malloc(t->bt_reclen) :
realloc(t->bt_rdata.data, t->bt_reclen);
if (t->bt_rdata.data == NULL)
return (RET_ERROR);
t->bt_rdata.size = t->bt_reclen;
}
data.data = t->bt_rdata.data;
data.size = t->bt_reclen;
sp = (u_char *)t->bt_cmap;
ep = (u_char *)t->bt_emap;
for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
if (sp >= ep) {
F_SET(t, R_EOF);
return (RET_SPECIAL);
}
len = t->bt_reclen;
for (p = t->bt_rdata.data;
sp < ep && len > 0; *p++ = *sp++, --len);
if (len != 0)
memset(p, t->bt_bval, len);
if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
return (RET_ERROR);
}
t->bt_cmap = (caddr_t)sp;
return (RET_SUCCESS);
}
/*
* __REC_VMAP -- Get variable length records from a file.
*
* Parameters:
* t: tree
* cnt: records to read
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__rec_vmap(t, top)
BTREE *t;
recno_t top;
{
DBT data;
u_char *sp, *ep;
recno_t nrec;
int bval;
sp = (u_char *)t->bt_cmap;
ep = (u_char *)t->bt_emap;
bval = t->bt_bval;
for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
if (sp >= ep) {
F_SET(t, R_EOF);
return (RET_SPECIAL);
}
for (data.data = sp; sp < ep && *sp != bval; ++sp);
data.size = sp - (u_char *)data.data;
if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
return (RET_ERROR);
++sp;
}
t->bt_cmap = (caddr_t)sp;
return (RET_SUCCESS);
}