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path: root/db2/btree/bt_recno.c
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Diffstat (limited to 'db2/btree/bt_recno.c')
-rw-r--r--db2/btree/bt_recno.c1195
1 files changed, 1195 insertions, 0 deletions
diff --git a/db2/btree/bt_recno.c b/db2/btree/bt_recno.c
new file mode 100644
index 0000000000..cd8872a064
--- /dev/null
+++ b/db2/btree/bt_recno.c
@@ -0,0 +1,1195 @@
+/*-
+ * 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);
+}