1 files changed, 383 insertions, 0 deletions
diff --git a/db2/db/db_overflow.c b/db2/db/db_overflow.c
new file mode 100644
index 0000000000..2340e9e358
--- /dev/null
+++ b/db2/db/db_overflow.c
@@ -0,0 +1,383 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ *	Sleepycat Software.  All rights reserved.
+ */
+/*
+ * Copyright (c) 1990, 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ */
+/*
+ * Copyright (c) 1990, 1993, 1994, 1995
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * 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.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)db_overflow.c	10.4 (Sleepycat) 7/2/97";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#endif
+
+#include "db_int.h"
+#include "db_page.h"
+#include "db_am.h"
+#include "common_ext.h"
+
+/*
+ * Big key/data code.
+ *
+ * Big key and data entries are stored on linked lists of pages.  The initial
+ * reference is a structure with the total length of the item and the page
+ * number where it begins.  Each entry in the linked list contains a pointer
+ * to the next page of data, and so on.
+ */
+
+/*
+ * __db_goff --
+ *	Get an offpage item.
+ *
+ * PUBLIC: int __db_goff __P((DB *, DBT *,
+ * PUBLIC:     u_int32_t, db_pgno_t, void **, u_int32_t *));
+ */
+int
+__db_goff(dbp, dbt, tlen, pgno, bpp, bpsz)
+	DB *dbp;
+	DBT *dbt;
+	u_int32_t tlen;
+	db_pgno_t pgno;
+	void **bpp;
+	u_int32_t *bpsz;
+{
+	PAGE *h;
+	db_indx_t bytes;
+	int ret;
+	u_int32_t curoff, needed, start;
+	u_int8_t *p, *src;
+
+	/*
+	 * Check if the buffer is big enough; if it is not and we are
+	 * allowed to malloc space, then we'll malloc it.  If we are
+	 * not (DB_DBT_USERMEM), then we'll set the dbt and return
+	 * appropriately.
+	 */
+	if (F_ISSET(dbt, DB_DBT_PARTIAL)) {
+		start = dbt->doff;
+		needed = dbt->dlen;
+	} else {
+		start = 0;
+		needed = tlen;
+	}
+
+	/*
+	 * Allocate any necessary memory.
+	 *
+	 * XXX: Never allocate 0 bytes;
+	 */
+	if (F_ISSET(dbt, DB_DBT_USERMEM)) {
+		if (needed > dbt->ulen) {
+			dbt->size = needed;
+			return (ENOMEM);
+		}
+	} else if (F_ISSET(dbt, DB_DBT_MALLOC)) {
+		dbt->data = dbp->db_malloc == NULL ?
+		    (void *)malloc(needed + 1) :
+		    (void *)dbp->db_malloc(needed + 1);
+		if (dbt->data == NULL)
+			return (ENOMEM);
+	} else if (*bpsz == 0 || *bpsz < needed) {
+		*bpp = (*bpp == NULL ?
+		    (void *)malloc(needed + 1) :
+		    (void *)realloc(*bpp, needed + 1));
+		if (*bpp == NULL)
+			return (ENOMEM);
+		*bpsz = needed + 1;
+		dbt->data = *bpp;
+	} else
+		dbt->data = *bpp;
+
+	/*
+	 * Step through the linked list of pages, copying the data on each
+	 * one into the buffer.  Never copy more than the total data length.
+	 */
+	dbt->size = needed;
+	for (curoff = 0, p = dbt->data; pgno != P_INVALID && needed > 0;) {
+		if ((ret = memp_fget(dbp->mpf, &pgno, 0, &h)) != 0) {
+			(void)__db_pgerr(dbp, pgno);
+			return (ret);
+		}
+		/* Check if we need any bytes from this page. */
+		if (curoff + OV_LEN(h) >= start) {
+			src = (u_int8_t *)h + P_OVERHEAD;
+			bytes = OV_LEN(h);
+			if (start > curoff) {
+				src += start - curoff;
+				bytes -= start - curoff;
+			}
+			if (bytes > needed)
+				bytes = needed;
+			memcpy(p, src, bytes);
+			p += bytes;
+			needed -= bytes;
+		}
+		curoff += OV_LEN(h);
+		pgno = h->next_pgno;
+		memp_fput(dbp->mpf, h, 0);
+	}
+	return (0);
+}
+
+/*
+ * __db_poff --
+ *	Put an offpage item.
+ *
+ * PUBLIC: int __db_poff __P((DB *, const DBT *, db_pgno_t *,
+ * PUBLIC:     int (*)(DB *, u_int32_t, PAGE **)));
+ */
+int
+__db_poff(dbp, dbt, pgnop, newfunc)
+	DB *dbp;
+	const DBT *dbt;
+	db_pgno_t *pgnop;
+	int (*newfunc) __P((DB *, u_int32_t, PAGE **));
+{
+	PAGE *pagep, *lastp;
+	DB_LSN new_lsn, null_lsn;
+	DBT tmp_dbt;
+	db_indx_t pagespace;
+	u_int32_t sz;
+	u_int8_t *p;
+	int ret;
+
+	/*
+	 * Allocate pages and copy the key/data item into them.  Calculate the
+	 * number of bytes we get for pages we fill completely with a single
+	 * item.
+	 */
+	pagespace = P_MAXSPACE(dbp->pgsize);
+
+	lastp = NULL;
+	for (p = dbt->data,
+	    sz = dbt->size; sz > 0; p += pagespace, sz -= pagespace) {
+		/*
+		 * Reduce pagespace so we terminate the loop correctly and
+		 * don't copy too much data.
+		 */
+		if (sz < pagespace)
+			pagespace = sz;
+
+		/*
+		 * Allocate and initialize a new page and copy all or part of
+		 * the item onto the page.  If sz is less than pagespace, we
+		 * have a partial record.
+		 */
+		if ((ret = newfunc(dbp, P_OVERFLOW, &pagep)) != 0)
+			return (ret);
+		if (DB_LOGGING(dbp)) {
+			tmp_dbt.data = p;
+			tmp_dbt.size = pagespace;
+			ZERO_LSN(null_lsn);
+			if ((ret = __db_big_log(dbp->dbenv->lg_info, dbp->txn,
+			    &new_lsn, 0, DB_ADD_BIG, dbp->log_fileid,
+			    PGNO(pagep), lastp ? PGNO(lastp) : PGNO_INVALID,
+			    PGNO_INVALID, &tmp_dbt, &LSN(pagep),
+			    lastp == NULL ? &null_lsn : &LSN(lastp),
+			    &null_lsn)) != 0)
+				return (ret);
+
+			/* Move lsn onto page. */
+			if (lastp)
+				LSN(lastp) = new_lsn;
+			LSN(pagep) = new_lsn;
+		}
+
+		P_INIT(pagep, dbp->pgsize,
+		    PGNO(pagep), PGNO_INVALID, PGNO_INVALID, 0, P_OVERFLOW);
+		OV_LEN(pagep) = pagespace;
+		OV_REF(pagep) = 1;
+		memcpy((u_int8_t *)pagep + P_OVERHEAD, p, pagespace);
+
+		/*
+		 * If this is the first entry, update the user's info.
+		 * Otherwise, update the entry on the last page filled
+		 * in and release that page.
+		 */
+		if (lastp == NULL)
+			*pgnop = PGNO(pagep);
+		else {
+			lastp->next_pgno = PGNO(pagep);
+			pagep->prev_pgno = PGNO(lastp);
+			(void)memp_fput(dbp->mpf, lastp, DB_MPOOL_DIRTY);
+		}
+		lastp = pagep;
+	}
+	(void)memp_fput(dbp->mpf, lastp, DB_MPOOL_DIRTY);
+	return (0);
+}
+
+/*
+ * __db_ioff --
+ *	Increment the reference count on an overflow page.
+ *
+ * PUBLIC: int __db_ioff __P((DB *, db_pgno_t));
+ */
+int
+__db_ioff(dbp, pgno)
+	DB *dbp;
+	db_pgno_t pgno;
+{
+	PAGE *h;
+	int ret;
+
+	if ((ret = memp_fget(dbp->mpf, &pgno, 0, &h)) != 0) {
+		(void)__db_pgerr(dbp, pgno);
+		return (ret);
+	}
+
+	++OV_REF(h);
+	if (DB_LOGGING(dbp) && (ret = __db_ovref_log(dbp->dbenv->lg_info,
+	    dbp->txn, &LSN(h), 0, dbp->log_fileid, h->pgno, &LSN(h))) != 0)
+		return (ret);
+
+	(void)memp_fput(dbp->mpf, h, DB_MPOOL_DIRTY);
+	return (0);
+}
+
+/*
+ * __db_doff --
+ *	Delete an offpage chain of overflow pages.
+ *
+ * PUBLIC: int __db_doff __P((DB *, db_pgno_t, int (*)(DB *, PAGE *)));
+ */
+int
+__db_doff(dbp, pgno, freefunc)
+	DB *dbp;
+	db_pgno_t pgno;
+	int (*freefunc) __P((DB *, PAGE *));
+{
+	PAGE *pagep;
+	DB_LSN null_lsn;
+	DBT tmp_dbt;
+	int ret;
+
+	do {
+		if ((ret = memp_fget(dbp->mpf, &pgno, 0, &pagep)) != 0) {
+			(void)__db_pgerr(dbp, pgno);
+			return (ret);
+		}
+
+		/*
+		 * If it's an overflow page and it's referenced by more than
+		 * one key/data item, decrement the reference count and return.
+		 */
+		if (TYPE(pagep) == P_OVERFLOW && OV_REF(pagep) > 1) {
+			--OV_REF(pagep);
+			(void)memp_fput(dbp->mpf, pagep, DB_MPOOL_DIRTY);
+			return (0);
+		}
+
+		if (DB_LOGGING(dbp)) {
+			tmp_dbt.data = (u_int8_t *)pagep + P_OVERHEAD;
+			tmp_dbt.size = OV_LEN(pagep);
+			ZERO_LSN(null_lsn);
+			if ((ret = __db_big_log(dbp->dbenv->lg_info, dbp->txn,
+			    &LSN(pagep), 0, DB_REM_BIG, dbp->log_fileid,
+			    PGNO(pagep), PREV_PGNO(pagep), NEXT_PGNO(pagep),
+			    &tmp_dbt, &LSN(pagep), &null_lsn, &null_lsn)) != 0)
+				return (ret);
+		}
+		pgno = pagep->next_pgno;
+		if ((ret = freefunc(dbp, pagep)) != 0)
+			return (ret);
+	} while (pgno != PGNO_INVALID);
+
+	return (0);
+}
+
+/*
+ * __db_moff --
+ *	Match on overflow pages.
+ *
+ * Given a starting page number and a key, return <0, 0, >0 to indicate if the
+ * key on the page is less than, equal to or greater than the key specified.
+ *
+ * PUBLIC: int __db_moff __P((DB *, const DBT *, db_pgno_t));
+ */
+int
+__db_moff(dbp, dbt, pgno)
+	DB *dbp;
+	const DBT *dbt;
+	db_pgno_t pgno;
+{
+	PAGE *pagep;
+	u_int32_t cmp_bytes, key_left;
+	int ret;
+	u_int8_t *p1, *p2;
+
+	/* While there are both keys to compare. */
+	for (ret = 0, p1 = dbt->data,
+	    key_left = dbt->size; key_left > 0 && pgno != PGNO_INVALID;) {
+		if (memp_fget(dbp->mpf, &pgno, 0, &pagep) != 0) {
+			(void)__db_pgerr(dbp, pgno);
+			return (0);	/* No system error return. */
+		}
+
+		cmp_bytes = OV_LEN(pagep) < key_left ? OV_LEN(pagep) : key_left;
+		key_left -= cmp_bytes;
+		for (p2 =
+		    (u_int8_t *)pagep + P_OVERHEAD; cmp_bytes-- > 0; ++p1, ++p2)
+			if (*p1 != *p2) {
+				ret = (long)*p1 - (long)*p2;
+				break;
+			}
+		pgno = NEXT_PGNO(pagep);
+		(void)memp_fput(dbp->mpf, pagep, 0);
+		if (ret != 0)
+			return (ret);
+	}
+	if (key_left > 0)		/* DBT is longer than page key. */
+		return (-1);
+	if (pgno != PGNO_INVALID)	/* DBT is shorter than page key. */
+		return (1);
+	return (0);
+}