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glibc/db2/btree/bt_recno.c

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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997
* Sleepycat Software. All rights reserved.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)bt_recno.c 10.12 (Sleepycat) 8/25/97";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#endif
#include "db_int.h"
#include "db_page.h"
#include "btree.h"
static int __ram_add __P((DB *, db_recno_t *, DBT *, int, int));
static int __ram_c_close __P((DBC *));
static int __ram_c_del __P((DBC *, int));
static int __ram_c_get __P((DBC *, DBT *, DBT *, int));
static int __ram_c_put __P((DBC *, DBT *, DBT *, int));
static int __ram_fmap __P((DB *, db_recno_t));
static int __ram_get __P((DB *, DB_TXN *, DBT *, DBT *, int));
static int __ram_put __P((DB *, DB_TXN *, DBT *, DBT *, int));
static int __ram_source __P((DB *, RECNO *, const char *));
static int __ram_sync __P((DB *, int));
static int __ram_update __P((DB *, db_recno_t, int));
static int __ram_vmap __P((DB *, db_recno_t));
static int __ram_writeback __P((DB *));
/*
* If we're renumbering records, then we have to detect in the cursor that a
* record was deleted, and adjust the cursor as necessary. If not renumbering
* records, then we can detect this by looking at the actual record, so we
* ignore the cursor delete flag.
*/
#define CD_SET(dbp, cp) { \
if (F_ISSET(dbp, DB_RE_RENUMBER)) \
F_SET(cp, CR_DELETED); \
}
#define CD_CLR(dbp, cp) { \
if (F_ISSET(dbp, DB_RE_RENUMBER)) \
F_CLR(cp, CR_DELETED); \
}
#define CD_ISSET(dbp, cp) \
(F_ISSET(dbp, DB_RE_RENUMBER) && F_ISSET(cp, CR_DELETED))
/*
* __ram_open --
* Recno open function.
*
* PUBLIC: int __ram_open __P((DB *, DBTYPE, DB_INFO *));
*/
int
__ram_open(dbp, type, dbinfo)
DB *dbp;
DBTYPE type;
DB_INFO *dbinfo;
{
BTREE *t;
RECNO *rp;
int ret;
ret = 0;
/* Allocate and initialize the private RECNO structure. */
if ((rp = (RECNO *)calloc(1, sizeof(*rp))) == NULL)
return (errno);
if (dbinfo != NULL) {
/*
* If the user specified a source tree, open it and map it in.
*
* !!!
* We don't complain if the user specified transactions or
* threads. It's possible to make it work, but you'd better
* know what you're doing!
*/
if (dbinfo->re_source == NULL) {
rp->re_fd = -1;
F_SET(rp, RECNO_EOF);
} else {
if ((ret =
__ram_source(dbp, rp, dbinfo->re_source)) != 0)
goto err;
}
/* Copy delimiter, length and padding values. */
rp->re_delim =
F_ISSET(dbp, DB_RE_DELIMITER) ? dbinfo->re_delim : '\n';
rp->re_pad = F_ISSET(dbp, DB_RE_PAD) ? dbinfo->re_pad : ' ';
if (F_ISSET(dbp, DB_RE_FIXEDLEN)) {
if ((rp->re_len = dbinfo->re_len) == 0) {
__db_err(dbp->dbenv,
"record length must be greater than 0");
ret = EINVAL;
goto err;
}
} else
rp->re_len = 0;
} else {
rp->re_delim = '\n';
rp->re_pad = ' ';
rp->re_fd = -1;
F_SET(rp, RECNO_EOF);
}
/* Open the underlying btree. */
if ((ret = __bam_open(dbp, DB_RECNO, dbinfo)) != 0)
goto err;
/* Set the routines necessary to make it look like a recno tree. */
dbp->cursor = __ram_cursor;
dbp->del = __ram_delete;
dbp->get = __ram_get;
dbp->put = __ram_put;
dbp->sync = __ram_sync;
/* Link in the private recno structure. */
((BTREE *)dbp->internal)->bt_recno = rp;
/* If we're snapshotting an underlying source file, do it now. */
if (dbinfo != NULL && F_ISSET(dbinfo, DB_SNAPSHOT))
if ((ret = __ram_snapshot(dbp)) != 0 && ret != DB_NOTFOUND)
goto err;
return (0);
err: /* If we mmap'd a source file, discard it. */
if (rp->re_smap != NULL)
(void)__db_munmap(rp->re_smap, rp->re_msize);
/* If we opened a source file, discard it. */
if (rp->re_fd != -1)
(void)__db_close(rp->re_fd);
if (rp->re_source != NULL)
FREES(rp->re_source);
/* If we allocated room for key/data return, discard it. */
t = dbp->internal;
if (t->bt_rkey.data != NULL)
free(t->bt_rkey.data);
FREE(rp, sizeof(*rp));
return (ret);
}
/*
* __ram_cursor --
* Recno db->cursor function.
*
* PUBLIC: int __ram_cursor __P((DB *, DB_TXN *, DBC **));
*/
int
__ram_cursor(dbp, txn, dbcp)
DB *dbp;
DB_TXN *txn;
DBC **dbcp;
{
RCURSOR *cp;
DBC *dbc;
DEBUG_LWRITE(dbp, txn, "ram_cursor", NULL, NULL, 0);
if ((dbc = (DBC *)calloc(1, sizeof(DBC))) == NULL)
return (ENOMEM);
if ((cp = (RCURSOR *)calloc(1, sizeof(RCURSOR))) == NULL) {
free(dbc);
return (ENOMEM);
}
cp->dbc = dbc;
cp->recno = RECNO_OOB;
dbc->dbp = dbp;
dbc->txn = txn;
dbc->internal = cp;
dbc->c_close = __ram_c_close;
dbc->c_del = __ram_c_del;
dbc->c_get = __ram_c_get;
dbc->c_put = __ram_c_put;
/* All cursor structures hang off the main DB structure. */
DB_THREAD_LOCK(dbp);
TAILQ_INSERT_HEAD(&dbp->curs_queue, dbc, links);
DB_THREAD_UNLOCK(dbp);
*dbcp = dbc;
return (0);
}
/*
* __ram_get --
* Recno db->get function.
*/
static int
__ram_get(argdbp, txn, key, data, flags)
DB *argdbp;
DB_TXN *txn;
DBT *key, *data;
int flags;
{
BTREE *t;
DB *dbp;
PAGE *h;
db_indx_t indx;
db_recno_t recno;
int exact, ret, stack;
stack = 0;
DEBUG_LWRITE(argdbp, txn, "ram_get", key, NULL, flags);
/* Check for invalid flags. */
if ((ret = __db_getchk(argdbp, key, data, flags)) != 0)
return (ret);
GETHANDLE(argdbp, txn, &dbp, ret);
t = dbp->internal;
/* Check the user's record number and fill in as necessary. */
if ((ret = __ram_getno(dbp, key, &recno, 0)) != 0)
goto done;
/* Search the tree for the record. */
if ((ret = __bam_rsearch(dbp, &recno, S_FIND, 1, &exact)) != 0)
goto done;
if (!exact)
return (DB_NOTFOUND);
stack = 1;
h = t->bt_csp->page;
indx = t->bt_csp->indx;
/* If the record has already been deleted, we couldn't have found it. */
if (GET_BKEYDATA(h, indx)->deleted) {
ret = DB_KEYEMPTY;
goto done;
}
/* Return the data item. */
ret = __db_ret(dbp,
h, indx, data, &t->bt_rdata.data, &t->bt_rdata.ulen);
++t->lstat.bt_get;
done: /* Discard the stack. */
if (stack)
__bam_stkrel(dbp);
PUTHANDLE(dbp);
return (ret);
}
/*
* __ram_put --
* Recno db->put function.
*/
static int
__ram_put(argdbp, txn, key, data, flags)
DB *argdbp;
DB_TXN *txn;
DBT *key, *data;
int flags;
{
BTREE *t;
DB *dbp;
db_recno_t recno;
int ret;
DEBUG_LWRITE(argdbp, txn, "ram_put", key, data, flags);
/* Check for invalid flags. */
if ((ret = __db_putchk(argdbp,
key, data, flags, F_ISSET(argdbp, DB_AM_RDONLY), 0)) != 0)
return (ret);
GETHANDLE(argdbp, txn, &dbp, ret);
/*
* If we're appending to the tree, make sure we've read in all of
* the backing source file. Otherwise, check the user's record
* number and fill in as necessary.
*/
ret = LF_ISSET(DB_APPEND) ?
__ram_snapshot(dbp) : __ram_getno(dbp, key, &recno, 1);
/* Add the record. */
if (ret == 0)
ret = __ram_add(dbp, &recno, data, flags, 0);
/* If we're appending to the tree, we have to return the record. */
if (ret == 0 && LF_ISSET(DB_APPEND)) {
t = dbp->internal;
ret = __db_retcopy(key, &recno, sizeof(recno),
&t->bt_rkey.data, &t->bt_rkey.ulen, dbp->db_malloc);
}
PUTHANDLE(dbp);
return (ret);
}
/*
* __ram_sync --
* Recno db->sync function.
*/
static int
__ram_sync(argdbp, flags)
DB *argdbp;
int flags;
{
DB *dbp;
int ret;
DEBUG_LWRITE(argdbp, NULL, "ram_sync", NULL, NULL, flags);
/* Sync the underlying btree. */
if ((ret = __bam_sync(argdbp, flags)) != 0)
return (ret);
/* Copy back the backing source file. */
GETHANDLE(argdbp, NULL, &dbp, ret);
ret = __ram_writeback(dbp);
PUTHANDLE(dbp);
return (ret);
}
/*
* __ram_close --
* Recno db->close function.
*
* PUBLIC: int __ram_close __P((DB *));
*/
int
__ram_close(argdbp)
DB *argdbp;
{
RECNO *rp;
DEBUG_LWRITE(argdbp, NULL, "ram_close", NULL, NULL, 0);
rp = ((BTREE *)argdbp->internal)->bt_recno;
/* Close any underlying mmap region. */
if (rp->re_smap != NULL)
(void)__db_munmap(rp->re_smap, rp->re_msize);
/* Close any backing source file descriptor. */
if (rp->re_fd != -1)
(void)__db_close(rp->re_fd);
/* Free any backing source file name. */
if (rp->re_source != NULL)
FREES(rp->re_source);
/* Free allocated memory. */
FREE(rp, sizeof(RECNO));
((BTREE *)argdbp->internal)->bt_recno = NULL;
/* Close the underlying btree. */
return (__bam_close(argdbp));
}
/*
* __ram_c_close --
* Recno cursor->close function.
*/
static int
__ram_c_close(dbc)
DBC *dbc;
{
DB *dbp;
DEBUG_LWRITE(dbc->dbp, dbc->txn, "ram_c_close", NULL, NULL, 0);
dbp = dbc->dbp;
/* Remove the cursor from the queue. */
DB_THREAD_LOCK(dbp);
TAILQ_REMOVE(&dbp->curs_queue, dbc, links);
DB_THREAD_UNLOCK(dbp);
/* Discard the structures. */
FREE(dbc->internal, sizeof(RCURSOR));
FREE(dbc, sizeof(DBC));
return (0);
}
/*
* __ram_c_del --
* Recno cursor->c_del function.
*/
static int
__ram_c_del(dbc, flags)
DBC *dbc;
int flags;
{
DBT key;
RCURSOR *cp;
int ret;
DEBUG_LWRITE(dbc->dbp, dbc->txn, "ram_c_del", NULL, NULL, flags);
cp = dbc->internal;
/* Check for invalid flags. */
if ((ret = __db_cdelchk(dbc->dbp, flags,
F_ISSET(dbc->dbp, DB_AM_RDONLY), cp->recno != RECNO_OOB)) != 0)
return (ret);
/* If already deleted, return failure. */
if (CD_ISSET(dbc->dbp, cp))
return (DB_KEYEMPTY);
/* Build a normal delete request. */
memset(&key, 0, sizeof(key));
key.data = &cp->recno;
key.size = sizeof(db_recno_t);
if ((ret = __ram_delete(dbc->dbp, dbc->txn, &key, 0)) == 0)
CD_SET(dbc->dbp, cp);
return (ret);
}
/*
* __ram_c_get --
* Recno cursor->c_get function.
*/
static int
__ram_c_get(dbc, key, data, flags)
DBC *dbc;
DBT *key, *data;
int flags;
{
BTREE *t;
DB *dbp;
RCURSOR *cp, copy;
int ret;
DEBUG_LREAD(dbc->dbp, dbc->txn, "ram_c_get",
flags == DB_SET || flags == DB_SET_RANGE ? key : NULL,
NULL, flags);
cp = dbc->internal;
dbp = dbc->dbp;
/* Check for invalid flags. */
if ((ret = __db_cgetchk(dbc->dbp,
key, data, flags, cp->recno != RECNO_OOB)) != 0)
return (ret);
GETHANDLE(dbc->dbp, dbc->txn, &dbp, ret);
t = dbp->internal;
/* Initialize the cursor for a new retrieval. */
copy = *cp;
retry: /* Update the record number. */
switch (flags) {
case DB_CURRENT:
if (CD_ISSET(dbp, cp)) {
PUTHANDLE(dbp);
return (DB_KEYEMPTY);
}
break;
case DB_NEXT:
if (CD_ISSET(dbp, cp))
break;
if (cp->recno != RECNO_OOB) {
++cp->recno;
break;
}
/* FALLTHROUGH */
case DB_FIRST:
flags = DB_NEXT;
cp->recno = 1;
break;
case DB_PREV:
if (cp->recno != RECNO_OOB) {
if (cp->recno == 1)
return (DB_NOTFOUND);
--cp->recno;
break;
}
/* FALLTHROUGH */
case DB_LAST:
flags = DB_PREV;
if (((ret = __ram_snapshot(dbp)) != 0) && ret != DB_NOTFOUND)
goto err;
if ((ret = __bam_nrecs(dbp, &cp->recno)) != 0)
goto err;
if (cp->recno == 0)
return (DB_NOTFOUND);
break;
case DB_SET:
case DB_SET_RANGE:
if ((ret = __ram_getno(dbp, key, &cp->recno, 0)) != 0)
goto err;
break;
}
/*
* Return the key if the user didn't give us one, and then pass it
* into __ram_get().
*/
if (flags != DB_SET && flags != DB_SET_RANGE &&
(ret = __db_retcopy(key, &cp->recno, sizeof(cp->recno),
&t->bt_rkey.data, &t->bt_rkey.ulen, dbp->db_malloc)) != 0)
return (ret);
/*
* The cursor was reset, so the delete adjustment is no
* longer necessary.
*/
CD_CLR(dbp, cp);
/*
* Retrieve the record.
*
* Skip any keys that don't really exist.
*/
if ((ret = __ram_get(dbp, dbc->txn, key, data, 0)) != 0)
if (ret == DB_KEYEMPTY &&
(flags == DB_NEXT || flags == DB_PREV))
goto retry;
err: if (ret != 0)
*cp = copy;
PUTHANDLE(dbp);
return (ret);
}
/*
* __ram_c_put --
* Recno cursor->c_put function.
*/
static int
__ram_c_put(dbc, key, data, flags)
DBC *dbc;
DBT *key, *data;
int flags;
{
BTREE *t;
RCURSOR *cp, copy;
DB *dbp;
int exact, ret;
void *arg;
DEBUG_LWRITE(dbc->dbp, dbc->txn, "ram_c_put", NULL, data, flags);
cp = dbc->internal;
if ((ret = __db_cputchk(dbc->dbp, key, data, flags,
F_ISSET(dbc->dbp, DB_AM_RDONLY), cp->recno != RECNO_OOB)) != 0)
return (ret);
GETHANDLE(dbc->dbp, dbc->txn, &dbp, ret);
t = dbp->internal;
/* Initialize the cursor for a new retrieval. */
copy = *cp;
/*
* To split, we need a valid key for the page. Since it's a cursor,
* we have to build one.
*
* The split code discards all short-term locks and stack pages.
*/
if (0) {
split: arg = &cp->recno;
if ((ret = __bam_split(dbp, arg)) != 0)
goto err;
}
if ((ret = __bam_rsearch(dbp, &cp->recno, S_INSERT, 1, &exact)) != 0)
goto err;
if (!exact) {
ret = DB_NOTFOUND;
goto err;
}
if ((ret = __bam_iitem(dbp, &t->bt_csp->page,
&t->bt_csp->indx, key, data, flags, 0)) == DB_NEEDSPLIT) {
if ((ret = __bam_stkrel(dbp)) != 0)
goto err;
goto split;
}
if ((ret = __bam_stkrel(dbp)) != 0)
goto err;
if (flags != DB_CURRENT) {
/* Adjust the counts. */
if ((ret = __bam_adjust(dbp, t, 1)) != 0)
goto err;
switch (flags) {
case DB_AFTER:
/* Adjust the cursors. */
__ram_ca(dbp, cp->recno, CA_IAFTER);
/* Set this cursor to reference the new record. */
cp->recno = copy.recno + 1;
break;
case DB_BEFORE:
/* Adjust the cursors. */
__ram_ca(dbp, cp->recno, CA_IBEFORE);
/* Set this cursor to reference the new record. */
cp->recno = copy.recno;
break;
}
}
/*
* The cursor was reset, so the delete adjustment is no
* longer necessary.
*/
CD_CLR(dbp, cp);
err: if (ret != 0)
*cp = copy;
PUTHANDLE(dbp);
return (ret);
}
/*
* __ram_ca --
* Adjust cursors.
*
* PUBLIC: void __ram_ca __P((DB *, db_recno_t, ca_recno_arg));
*/
void
__ram_ca(dbp, recno, op)
DB *dbp;
db_recno_t recno;
ca_recno_arg op;
{
DBC *dbc;
RCURSOR *cp;
/*
* Adjust the cursors. See the comment in __bam_ca_delete().
*/
DB_THREAD_LOCK(dbp);
for (dbc = TAILQ_FIRST(&dbp->curs_queue);
dbc != NULL; dbc = TAILQ_NEXT(dbc, links)) {
cp = (RCURSOR *)dbc->internal;
switch (op) {
case CA_DELETE:
if (recno > cp->recno)
--cp->recno;
break;
case CA_IAFTER:
if (recno > cp->recno)
++cp->recno;
break;
case CA_IBEFORE:
if (recno >= cp->recno)
++cp->recno;
break;
}
}
DB_THREAD_UNLOCK(dbp);
}
#ifdef DEBUG
/*
* __ram_cprint --
* Display the current recno cursor list.
*/
int
__ram_cprint(dbp)
DB *dbp;
{
DBC *dbc;
RCURSOR *cp;
DB_THREAD_LOCK(dbp);
for (dbc = TAILQ_FIRST(&dbp->curs_queue);
dbc != NULL; dbc = TAILQ_NEXT(dbc, links)) {
cp = (RCURSOR *)dbc->internal;
fprintf(stderr,
"%#0x: recno: %lu\n", (u_int)cp, (u_long)cp->recno);
}
DB_THREAD_UNLOCK(dbp);
return (0);
}
#endif /* DEBUG */
/*
* __ram_getno --
* Check the user's record number, and make sure we've seen it.
*
* PUBLIC: int __ram_getno __P((DB *, const DBT *, db_recno_t *, int));
*/
int
__ram_getno(dbp, key, rep, can_create)
DB *dbp;
const DBT *key;
db_recno_t *rep;
int can_create;
{
db_recno_t recno;
/* Check the user's record number. */
if ((recno = *(db_recno_t *)key->data) == 0) {
__db_err(dbp->dbenv, "illegal record number of 0");
return (EINVAL);
}
if (rep != NULL)
*rep = recno;
/*
* Btree can neither create records or read them in. Recno can
* do both, see if we can find the record.
*/
return (dbp->type == DB_RECNO ?
__ram_update(dbp, recno, can_create) : 0);
}
/*
* __ram_snapshot --
* Read in any remaining records from the backing input file.
*
* PUBLIC: int __ram_snapshot __P((DB *));
*/
int
__ram_snapshot(dbp)
DB *dbp;
{
return (__ram_update(dbp, DB_MAX_RECORDS, 0));
}
/*
* __ram_update --
* Ensure the tree has records up to and including the specified one.
*/
static int
__ram_update(dbp, recno, can_create)
DB *dbp;
db_recno_t recno;
int can_create;
{
BTREE *t;
RECNO *rp;
db_recno_t nrecs;
int ret;
t = dbp->internal;
rp = t->bt_recno;
/*
* If we can't create records and we've read the entire backing input
* file, we're done.
*/
if (!can_create && F_ISSET(rp, RECNO_EOF))
return (0);
/*
* If we haven't seen this record yet, try to get it from the original
* file.
*/
if ((ret = __bam_nrecs(dbp, &nrecs)) != 0)
return (ret);
if (!F_ISSET(rp, RECNO_EOF) && recno > nrecs) {
if ((ret = rp->re_irec(dbp, recno)) != 0)
return (ret);
if ((ret = __bam_nrecs(dbp, &nrecs)) != 0)
return (ret);
}
/*
* If we can create records, create empty ones up to the requested
* record.
*/
if (!can_create || recno <= nrecs + 1)
return (0);
t->bt_rdata.dlen = 0;
t->bt_rdata.doff = 0;
t->bt_rdata.flags = 0;
if (F_ISSET(dbp, DB_RE_FIXEDLEN)) {
if (t->bt_rdata.ulen < rp->re_len) {
t->bt_rdata.data = t->bt_rdata.data == NULL ?
(void *)malloc(rp->re_len) :
(void *)realloc(t->bt_rdata.data, rp->re_len);
if (t->bt_rdata.data == NULL) {
t->bt_rdata.ulen = 0;
return (ENOMEM);
}
t->bt_rdata.ulen = rp->re_len;
}
t->bt_rdata.size = rp->re_len;
memset(t->bt_rdata.data, rp->re_pad, rp->re_len);
} else
t->bt_rdata.size = 0;
while (recno > ++nrecs)
if ((ret = __ram_add(dbp,
&nrecs, &t->bt_rdata, 0, BI_DELETED)) != 0)
return (ret);
return (0);
}
/*
* __ram_source --
* Load information about the backing file.
*/
static int
__ram_source(dbp, rp, fname)
DB *dbp;
RECNO *rp;
const char *fname;
{
off_t size;
int oflags, ret;
if ((ret = __db_appname(dbp->dbenv,
DB_APP_DATA, NULL, fname, NULL, &rp->re_source)) != 0)
return (ret);
oflags = F_ISSET(dbp, DB_AM_RDONLY) ? DB_RDONLY : 0;
if ((ret =
__db_fdopen(rp->re_source, oflags, oflags, 0, &rp->re_fd)) != 0) {
__db_err(dbp->dbenv, "%s: %s", rp->re_source, strerror(ret));
goto err;
}
/*
* XXX
* We'd like to test to see if the file is too big to mmap. Since we
* don't know what size or type off_t's or size_t's are, or the largest
* unsigned integral type is, or what random insanity the local C
* compiler will perpetrate, doing the comparison in a portable way is
* flatly impossible. Hope that mmap fails if the file is too large.
*/
if ((ret =
__db_stat(dbp->dbenv, rp->re_source, rp->re_fd, &size, NULL)) != 0)
goto err;
if (size == 0) {
F_SET(rp, RECNO_EOF);
return (0);
}
if ((ret = __db_mmap(rp->re_fd, (size_t)size, 1, 1, &rp->re_smap)) != 0)
goto err;
rp->re_cmap = rp->re_smap;
rp->re_emap = (u_int8_t *)rp->re_smap + (rp->re_msize = size);
rp->re_irec = F_ISSET(dbp, DB_RE_FIXEDLEN) ? __ram_fmap : __ram_vmap;
return (0);
err: FREES(rp->re_source)
return (ret);
}
/*
* __ram_writeback --
* Rewrite the backing file.
*/
static int
__ram_writeback(dbp)
DB *dbp;
{
RECNO *rp;
DBT key, data;
db_recno_t keyno;
ssize_t nw;
int fd, ret, t_ret;
u_int8_t delim, *pad;
rp = ((BTREE *)dbp->internal)->bt_recno;
/* If the file wasn't modified, we're done. */
if (!F_ISSET(rp, RECNO_MODIFIED))
return (0);
/* If there's no backing source file, we're done. */
if (rp->re_source == NULL) {
F_CLR(rp, RECNO_MODIFIED);
return (0);
}
/*
* Read any remaining records into the tree.
*
* XXX
* This is why we can't support transactions when applications specify
* backing (re_source) files. At this point we have to read in the
* rest of the records from the file so that we can write all of the
* records back out again, which could modify a page for which we'd
* have to log changes and which we don't have locked. This could be
* partially fixed by taking a snapshot of the entire file during the
* db_open(), or, since db_open() isn't transaction protected, as part
* of the first DB operation. But, if a checkpoint occurs then, the
* part of the log holding the copy of the file could be discarded, and
* that would make it impossible to recover in the face of disaster.
* This could all probably be fixed, but it would require transaction
* protecting the backing source file, i.e. mpool would have to know
* about it, and we don't want to go there.
*/
if ((ret = __ram_snapshot(dbp)) != 0 && ret != DB_NOTFOUND)
return (ret);
/*
* !!!
* Close any underlying mmap region. This is required for Windows NT
* (4.0, Service Pack 2) -- if the file is still mapped, the following
* open will fail.
*/
if (rp->re_smap != NULL) {
(void)__db_munmap(rp->re_smap, rp->re_msize);
rp->re_smap = NULL;
}
/* Get rid of any backing file descriptor, just on GP's. */
if (rp->re_fd != -1) {
(void)__db_close(rp->re_fd);
rp->re_fd = -1;
}
/* Open the file, truncating it. */
if ((ret = __db_fdopen(rp->re_source,
DB_SEQUENTIAL | DB_TRUNCATE,
DB_SEQUENTIAL | DB_TRUNCATE, 0, &fd)) != 0) {
__db_err(dbp->dbenv, "%s: %s", rp->re_source, strerror(ret));
return (ret);
}
/*
* We step through the records, writing each one out. Use the record
* number and the dbp->get() function, instead of a cursor, so we find
* and write out "deleted" or non-existent records.
*/
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
key.size = sizeof(db_recno_t);
key.data = &keyno;
/*
* We'll need the delimiter if we're doing variable-length records,
* and the pad character if we're doing fixed-length records.
*/
delim = rp->re_delim;
if (F_ISSET(dbp, DB_RE_FIXEDLEN)) {
if ((pad = malloc(rp->re_len)) == NULL) {
ret = ENOMEM;
goto err;
}
memset(pad, rp->re_pad, rp->re_len);
} else
pad = NULL; /* XXX: Shut the compiler up. */
for (keyno = 1;; ++keyno) {
switch (ret = dbp->get(dbp, NULL, &key, &data, 0)) {
case 0:
if ((ret =
__db_write(fd, data.data, data.size, &nw)) != 0)
goto err;
if (nw != (ssize_t)data.size) {
ret = EIO;
goto err;
}
break;
case DB_KEYEMPTY:
if (F_ISSET(dbp, DB_RE_FIXEDLEN)) {
if ((ret =
__db_write(fd, pad, rp->re_len, &nw)) != 0)
goto err;
if (nw != (ssize_t) rp->re_len) {
ret = EIO;
goto err;
}
}
break;
case DB_NOTFOUND:
ret = 0;
goto done;
}
if (!F_ISSET(dbp, DB_RE_FIXEDLEN)) {
if ((ret = __db_write(fd, &delim, 1, &nw)) != 0)
goto err;
if (nw != 1) {
ret = EIO;
goto err;
}
}
}
err:
done: /* Close the file descriptor. */
if ((t_ret = __db_close(fd)) != 0 || ret == 0)
ret = t_ret;
if (ret == 0)
F_CLR(rp, RECNO_MODIFIED);
return (ret);
}
/*
* __ram_fmap --
* Get fixed length records from a file.
*/
static int
__ram_fmap(dbp, top)
DB *dbp;
db_recno_t top;
{
BTREE *t;
DBT data;
RECNO *rp;
db_recno_t recno;
u_int32_t len;
u_int8_t *sp, *ep, *p;
int ret;
if ((ret = __bam_nrecs(dbp, &recno)) != 0)
return (ret);
t = dbp->internal;
rp = t->bt_recno;
if (t->bt_rdata.ulen < rp->re_len) {
t->bt_rdata.data = t->bt_rdata.data == NULL ?
(void *)malloc(rp->re_len) :
(void *)realloc(t->bt_rdata.data, rp->re_len);
if (t->bt_rdata.data == NULL) {
t->bt_rdata.ulen = 0;
return (ENOMEM);
}
t->bt_rdata.ulen = rp->re_len;
}
memset(&data, 0, sizeof(data));
data.data = t->bt_rdata.data;
data.size = rp->re_len;
sp = (u_int8_t *)rp->re_cmap;
ep = (u_int8_t *)rp->re_emap;
while (recno <= top) {
if (sp >= ep) {
F_SET(rp, RECNO_EOF);
return (DB_NOTFOUND);
}
len = rp->re_len;
for (p = t->bt_rdata.data;
sp < ep && len > 0; *p++ = *sp++, --len);
/*
* Another process may have read some portion of the input
* file already, in which case we just want to discard the
* new record.
*
* XXX
* We should just do a seek, since the records are fixed
* length.
*/
if (rp->re_last >= recno) {
if (len != 0)
memset(p, rp->re_pad, len);
++recno;
if ((ret = __ram_add(dbp, &recno, &data, 0, 0)) != 0)
return (ret);
}
++rp->re_last;
}
rp->re_cmap = sp;
return (0);
}
/*
* __ram_vmap --
* Get variable length records from a file.
*/
static int
__ram_vmap(dbp, top)
DB *dbp;
db_recno_t top;
{
BTREE *t;
DBT data;
RECNO *rp;
db_recno_t recno;
u_int8_t *sp, *ep;
int delim, ret;
t = dbp->internal;
rp = t->bt_recno;
if ((ret = __bam_nrecs(dbp, &recno)) != 0)
return (ret);
memset(&data, 0, sizeof(data));
delim = rp->re_delim;
sp = (u_int8_t *)rp->re_cmap;
ep = (u_int8_t *)rp->re_emap;
while (recno <= top) {
if (sp >= ep) {
F_SET(rp, RECNO_EOF);
return (DB_NOTFOUND);
}
for (data.data = sp; sp < ep && *sp != delim; ++sp);
/*
* Another process may have read some portion of the input
* file already, in which case we just want to discard the
* new record.
*/
if (rp->re_last >= recno) {
data.size = sp - (u_int8_t *)data.data;
++recno;
if ((ret = __ram_add(dbp, &recno, &data, 0, 0)) != 0)
return (ret);
}
++rp->re_last;
++sp;
}
rp->re_cmap = sp;
return (0);
}
/*
* __ram_add --
* Add records into the tree.
*/
static int
__ram_add(dbp, recnop, data, flags, bi_flags)
DB *dbp;
db_recno_t *recnop;
DBT *data;
int flags, bi_flags;
{
BTREE *t;
PAGE *h;
db_indx_t indx;
int exact, ret, stack;
t = dbp->internal;
retry: /* Find the slot for insertion. */
if ((ret = __bam_rsearch(dbp, recnop,
S_INSERT | (LF_ISSET(DB_APPEND) ? S_APPEND : 0), 1, &exact)) != 0)
return (ret);
h = t->bt_csp->page;
indx = t->bt_csp->indx;
stack = 1;
/*
* The recno access method doesn't currently support duplicates, so
* if an identical key is already in the tree we're either overwriting
* it or an error is returned.
*/
if (exact && LF_ISSET(DB_NOOVERWRITE)) {
ret = DB_KEYEXIST;
goto err;
}
/*
* Select the arguments for __bam_iitem() and do the insert. If the
* key is an exact match, or we're replacing the data item with a
* new data item. If the key isn't an exact match, we're inserting
* a new key/data pair, before the search location.
*/
if ((ret = __bam_iitem(dbp, &h, &indx, NULL,
data, exact ? DB_CURRENT : DB_BEFORE, bi_flags)) == DB_NEEDSPLIT) {
(void)__bam_stkrel(dbp);
stack = 0;
if ((ret = __bam_split(dbp, recnop)) != 0)
goto err;
goto retry;
}
if (!exact && ret == 0)
__bam_adjust(dbp, t, 1);
err: if (stack)
__bam_stkrel(dbp);
return (ret);
}
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