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authorUlrich Drepper <drepper@redhat.com>1997-08-27 20:26:10 +0000
committerUlrich Drepper <drepper@redhat.com>1997-08-27 20:26:10 +0000
commit92f1da4da04a7a86ddee91be5eaf0b10c333ac64 (patch)
tree2a10ce9e4e407e7e5b5ca092ca0947d234b5ff60 /db2/btree/bt_delete.c
parent22be878ecbc66606371bd33258f56e6711e6ba7a (diff)
1997-08-10 19:17 Philip Blundell <Philip.Blundell@pobox.com> * nss/nss_db/db-XXX.c: Include <db_185.h> not <db.h>. Somebody should update this to use the new db API. * nss/nss_db/db-netgrp.c: Likewise. * nss/nss_db/db-alias.c: Likewise. * db2/Makefile: Makefile for db-2.x in glibc. 1997-08-27 21:20 Ulrich Drepper <drepper@cygnus.com> * csu/Makefile (before-compile): New goal. Make sure abi-tag.h is generated. [$(elf)=yes] (asm-CPPFLAGS): Make sure abi-tag.h file can be found. * Makeconfig [$(build-omitfp)=yes] (CFLAGS-.o): Add -D__USE_STRING_INLINES. * string/string.f: Move strnlen optimization after inclusion of <bits/string.h>. Include <bits/string.h> only if __USE_STRING_INLINES is defined. * sysdeps/generic/memcpy.c: Undef memcpy to allow macro of this name in <bits/string.h>. * sysdeps/generic/memset.c: Likewise. * sysdeps/i386/string.h: i386 optimized string functions. * sysdeps/i386/i486string.h: i486+ optimized string functions. * Makefile (subdirs): Change db to db2. * shlib-versions: Bump libdb verion number to 3. * include/db.h: Include from db2 directory. * include/db_185.h: New file. * sysdeps/i386/Makefile [$(subdirs)=db2] (CPPFLAGS): Add macros to provide spinlock information for db2. * sysdeps/m68k/m68020/Makefile: New file. Likewise. * sysdeps/sparc/Makefile: New file. Likewise. * sysdeps/unix/sysv/linux/Makefile [$(subdirs)=db2] (CPPFLAGS): Add -DHAVE_LLSEEK. * db2/config.h: Hand-edited config file for db2 in glibc. * db2/compat.h: New file from db-2.3.4. * db2/db.h: Likewise. * db2/db_185.h: Likewise. * db2/db_int.h: Likewise. * db2/makedb.c: Likewise. * db2/btree/bt_close.c: Likewise. * db2/btree/bt_compare.c: Likewise. * db2/btree/bt_conv.c: Likewise. * db2/btree/bt_cursor.c: Likewise. * db2/btree/bt_delete.c: Likewise. * db2/btree/bt_open.c: Likewise. * db2/btree/bt_page.c: Likewise. * db2/btree/bt_put.c: Likewise. * db2/btree/bt_rec.c: Likewise. * db2/btree/bt_recno.c: Likewise. * db2/btree/btree_auto.c: Likewise. * db2/btree/bt_rsearch.c: Likewise. * db2/btree/bt_search.c: Likewise. * db2/btree/bt_split.c: Likewise. * db2/btree/bt_stat.c: Likewise. * db2/btree/btree.src: Likewise. * db2/common/db_appinit.c: Likewise. * db2/common/db_err.c: Likewise. * db2/common/db_byteorder.c: Likewise. * db2/common/db_apprec.c: Likewise. * db2/common/db_salloc.c: Likewise. * db2/common/db_log2.c: Likewise. * db2/common/db_region.c: Likewise. * db2/common/db_shash.c: Likewise. * db2/db/db.c: Likewise. * db2/db/db.src: Likewise. * db2/db/db_conv.c: Likewise. * db2/db/db_dispatch.c: Likewise. * db2/db/db_dup.c: Likewise. * db2/db/db_overflow.c: Likewise. * db2/db/db_pr.c: Likewise. * db2/db/db_rec.c: Likewise. * db2/db/db_ret.c: Likewise. * db2/db/db_thread.c: Likewise. * db2/db/db_auto.c: Likewise. * db2/db185/db185.c: Likewise. * db2/db185/db185_int.h: Likewise. * db2/dbm/dbm.c: Likewise. * db2/hash/hash.c: Likewise. * db2/hash/hash.src: Likewise. * db2/hash/hash_page.c: Likewise. * db2/hash/hash_conv.c: Likewise. * db2/hash/hash_debug.c: Likewise. * db2/hash/hash_stat.c: Likewise. * db2/hash/hash_rec.c: Likewise. * db2/hash/hash_dup.c: Likewise. * db2/hash/hash_func.c: Likewise. * db2/hash/hash_auto.c: Likewise. * db2/include/mp.h: Likewise. * db2/include/btree.h: Likewise. * db2/include/db.h.src: Likewise. * db2/include/db_int.h.src: Likewise. * db2/include/db_shash.h: Likewise. * db2/include/db_swap.h: Likewise. * db2/include/db_185.h.src: Likewise. * db2/include/txn.h: Likewise. * db2/include/db_am.h: Likewise. * db2/include/shqueue.h: Likewise. * db2/include/hash.h: Likewise. * db2/include/db_dispatch.h: Likewise. * db2/include/lock.h: Likewise. * db2/include/db_page.h: Likewise. * db2/include/log.h: Likewise. * db2/include/db_auto.h: Likewise. * db2/include/btree_auto.h: Likewise. * db2/include/hash_auto.h: Likewise. * db2/include/log_auto.h: Likewise. * db2/include/txn_auto.h: Likewise. * db2/include/db_ext.h: Likewise. * db2/include/btree_ext.h: Likewise. * db2/include/clib_ext.h: Likewise. * db2/include/common_ext.h: Likewise. * db2/include/hash_ext.h: Likewise. * db2/include/lock_ext.h: Likewise. * db2/include/log_ext.h: Likewise. * db2/include/mp_ext.h: Likewise. * db2/include/mutex_ext.h: Likewise. * db2/include/os_ext.h: Likewise. * db2/include/txn_ext.h: Likewise. * db2/include/cxx_int.h: Likewise. * db2/include/db_cxx.h: Likewise. * db2/include/queue.h: Likewise. * db2/lock/lock.c: Likewise. * db2/lock/lock_conflict.c: Likewise. * db2/lock/lock_util.c: Likewise. * db2/lock/lock_deadlock.c: Likewise. * db2/log/log.c: Likewise. * db2/log/log_get.c: Likewise. * db2/log/log.src: Likewise. * db2/log/log_compare.c: Likewise. * db2/log/log_put.c: Likewise. * db2/log/log_rec.c: Likewise. * db2/log/log_archive.c: Likewise. * db2/log/log_register.c: Likewise. * db2/log/log_auto.c: Likewise. * db2/log/log_findckp.c: Likewise. * db2/mp/mp_bh.c: Likewise. * db2/mp/mp_fget.c: Likewise. * db2/mp/mp_fopen.c: Likewise. * db2/mp/mp_fput.c: Likewise. * db2/mp/mp_fset.c: Likewise. * db2/mp/mp_open.c: Likewise. * db2/mp/mp_region.c: Likewise. * db2/mp/mp_pr.c: Likewise. * db2/mp/mp_sync.c: Likewise. * db2/mutex/68020.gcc: Likewise. * db2/mutex/mutex.c: Likewise. * db2/mutex/README: Likewise. * db2/mutex/x86.gcc: Likewise. * db2/mutex/sparc.gcc: Likewise. * db2/mutex/uts4.cc.s: Likewise. * db2/mutex/alpha.dec: Likewise. * db2/mutex/alpha.gcc: Likewise. * db2/mutex/parisc.gcc: Likewise. * db2/mutex/parisc.hp: Likewise. * db2/os/db_os_abs.c: Likewise. * db2/os/db_os_dir.c: Likewise. * db2/os/db_os_fid.c: Likewise. * db2/os/db_os_lseek.c: Likewise. * db2/os/db_os_mmap.c: Likewise. * db2/os/db_os_open.c: Likewise. * db2/os/db_os_rw.c: Likewise. * db2/os/db_os_sleep.c: Likewise. * db2/os/db_os_stat.c: Likewise. * db2/os/db_os_unlink.c: Likewise. * db2/txn/txn.c: Likewise. * db2/txn/txn.src: Likewise. * db2/txn/txn_rec.c: Likewise. * db2/txn/txn_auto.c: Likewise. * db2/clib/getlong.c: Likewise. * db2/progs/db_archive/db_archive.c: Likewise. * db2/progs/db_checkpoint/db_checkpoint.c: Likewise. * db2/progs/db_deadlock/db_deadlock.c: Likewise. * db2/progs/db_dump/db_dump.c: Likewise. * db2/progs/db_dump185/db_dump185.c: Likewise. * db2/progs/db_load/db_load.c: Likewise. * db2/progs/db_printlog/db_printlog.c: Likewise. * db2/progs/db_recover/db_recover.c: Likewise. * db2/progs/db_stat/db_stat.c: Likewise. * libio/stdio.h [__cplusplus] (__STDIO_INLINE): Define as inline. * po/de.po, po/sv.po: Update from 2.0.5 translations. * sysdeps/unix/sysv/linux/netinet/tcp.h: Pretty print. * sunrpc/rpc/xdr.h (XDR): Don't define argument of x_destroy callback as const. * sunrpc/xdr_mem.c (xdrmem_destroy): Don't define argument as const. * sunrpx/xdr_rec.c (xdrrec_destroy): Likewise. * sunrpx/xdr_stdio.c (xdrstdio_destroy): Likewise. 1997-08-27 18:47 Ulrich Drepper <drepper@cygnus.com> * sysdeps/unix/sysv/linux/if_index.c: Include <errno.h>. Reported by Benjamin Kosnik <bkoz@cygnus.com>. 1997-08-27 02:27 Roland McGrath <roland@baalperazim.frob.com> * abi-tags: New file. * csu/Makefile (distribute): Remove abi-tag.h. ($(objpfx)abi-tag.h): New target. * Makefile (distribute): Add abi-tags. * sysdeps/unix/sysv/linux/abi-tag.h: File removed. * sysdeps/mach/hurd/abi-tag.h: File removed. * sysdeps/stub/abi-tag.h: File removed. 1997-08-25 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/unix/make-syscalls.sh: Change output so that it generates compilation rules only for the currently selected object suffixes. 1997-08-25 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/m68k/dl-machine.h (RTLD_START): Switch back to previous section to avoid confusing the compiler. * sysdeps/alpha/dl-machine.h (RTLD_START): Likewise. * sysdeps/i386/dl-machine.h (RTLD_START): Likewise. * sysdeps/mips/dl-machine.h (RTLD_START): Likewise. * sysdeps/mips/mips64/dl-machine.h (RTLD_START): Likewise. * sysdeps/sparc/sparc32/dl-machine.h (RTLD_START): Likewise. * sysdeps/m68k/dl-machine.h (elf_machine_load_address): Use a GOT relocation instead of a constant to avoid text relocation. (ELF_MACHINE_BEFORE_RTLD_RELOC): Removed. (RTLD_START): Declare global labels as functions and add size directive. 1997-08-25 17:01 Ulrich Drepper <drepper@cygnus.com> * sysdeps/i386/bits/select.h: Correct assembler versions to work even for descriptors >= 32. * stdlib/alloca.h: Don't define alloca to __alloca since if gcc is used __alloca is not defined to __builtin_alloca and so might not be available. Reported by Uwe Ohse <uwe@ohse.de>. * sysdeps/unix/sysv/linux/sys/sysmacros.h: Define macros in a special way if gcc is not used and so dev_t is an array. Reported by Uwe Ohse <uwe@ohse.de>. 1997-08-23 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * manual/libc.texinfo: Reorder chapters to match logical order. 1997-08-25 12:22 Ulrich Drepper <drepper@cygnus.com> * sunrpc/rpc/xdr.h: Change name of parameters in prototypes of xdr_reference, xdrmem_create, and xdrstdio_create because of clash with g++ internal symbols. Patch by Sudish Joseph <sj@eng.mindspring.net>. * elf/dl-deps.c: Implement handling of DT_FILTER.
Diffstat (limited to 'db2/btree/bt_delete.c')
-rw-r--r--db2/btree/bt_delete.c607
1 files changed, 607 insertions, 0 deletions
diff --git a/db2/btree/bt_delete.c b/db2/btree/bt_delete.c
new file mode 100644
index 0000000000..e7ec4dfe3e
--- /dev/null
+++ b/db2/btree/bt_delete.c
@@ -0,0 +1,607 @@
+/*-
+ * 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[] = "@(#)bt_delete.c 10.18 (Sleepycat) 8/24/97";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <string.h>
+#endif
+
+#include "db_int.h"
+#include "db_page.h"
+#include "btree.h"
+
+static int __bam_dpages __P((DB *, BTREE *));
+
+/*
+ * __bam_delete --
+ * Delete the items referenced by a key.
+ *
+ * PUBLIC: int __bam_delete __P((DB *, DB_TXN *, DBT *, int));
+ */
+int
+__bam_delete(argdbp, txn, key, flags)
+ DB *argdbp;
+ DB_TXN *txn;
+ DBT *key;
+ int flags;
+{
+ BTREE *t;
+ DB *dbp;
+ PAGE *h;
+ db_indx_t cnt, i, indx;
+ int dpage, exact, ret, stack;
+
+ DEBUG_LWRITE(argdbp, txn, "bam_delete", key, NULL, flags);
+
+ stack = 0;
+
+ /* Check for invalid flags. */
+ if ((ret =
+ __db_delchk(argdbp, flags, F_ISSET(argdbp, DB_AM_RDONLY))) != 0)
+ return (ret);
+
+ GETHANDLE(argdbp, txn, &dbp, ret);
+ t = dbp->internal;
+
+ /* Search the tree for the key; delete only deletes exact matches. */
+ if ((ret = __bam_search(dbp, key, S_DELETE, 1, NULL, &exact)) != 0)
+ goto err;
+ stack = 1;
+ h = t->bt_csp->page;
+ indx = t->bt_csp->indx;
+
+ /* Delete the key/data pair, including any duplicates. */
+ for (cnt = 1, i = indx;; ++cnt)
+ if ((i += P_INDX) >= NUM_ENT(h) || h->inp[i] != h->inp[indx])
+ break;
+ for (; cnt > 0; --cnt, ++t->lstat.bt_deleted)
+ if (__bam_ca_delete(dbp, h->pgno, indx, NULL) != 0) {
+ GET_BKEYDATA(h, indx + O_INDX)->deleted = 1;
+ indx += P_INDX;
+ } else if ((ret = __bam_ditem(dbp, h, indx)) != 0 ||
+ (ret = __bam_ditem(dbp, h, indx)) != 0)
+ goto err;
+
+ /* If we're using record numbers, update internal page record counts. */
+ if (F_ISSET(dbp, DB_BT_RECNUM) && (ret = __bam_adjust(dbp, t, -1)) != 0)
+ goto err;
+
+ /* If the page is now empty, delete it. */
+ dpage = NUM_ENT(h) == 0 && h->pgno != PGNO_ROOT;
+
+ __bam_stkrel(dbp);
+ stack = 0;
+
+ ret = dpage ? __bam_dpage(dbp, key) : 0;
+
+err: if (stack)
+ __bam_stkrel(dbp);
+ PUTHANDLE(dbp);
+ return (ret);
+}
+
+/*
+ * __ram_delete --
+ * Delete the items referenced by a key.
+ *
+ * PUBLIC: int __ram_delete __P((DB *, DB_TXN *, DBT *, int));
+ */
+int
+__ram_delete(argdbp, txn, key, flags)
+ DB *argdbp;
+ DB_TXN *txn;
+ DBT *key;
+ int flags;
+{
+ BKEYDATA bk;
+ BTREE *t;
+ DB *dbp;
+ DBT hdr, data;
+ PAGE *h;
+ db_indx_t indx;
+ db_recno_t recno;
+ int exact, ret, stack;
+
+ stack = 0;
+
+ /* Check for invalid flags. */
+ if ((ret =
+ __db_delchk(argdbp, flags, F_ISSET(argdbp, DB_AM_RDONLY))) != 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(argdbp, key, &recno, 0)) != 0)
+ goto err;
+
+ /* Search the tree for the key; delete only deletes exact matches. */
+ if ((ret = __bam_rsearch(dbp, &recno, S_DELETE, 1, &exact)) != 0)
+ goto err;
+ if (!exact) {
+ ret = DB_NOTFOUND;
+ goto err;
+ }
+
+ h = t->bt_csp->page;
+ indx = t->bt_csp->indx;
+ stack = 1;
+
+ /* If the record has already been deleted, we couldn't have found it. */
+ if (GET_BKEYDATA(h, indx)->deleted) {
+ ret = DB_KEYEMPTY;
+ goto done;
+ }
+
+ /*
+ * If we're not renumbering records, replace the record with a marker
+ * and return.
+ */
+ if (!F_ISSET(dbp, DB_RE_RENUMBER)) {
+ if ((ret = __bam_ditem(dbp, h, indx)) != 0)
+ goto err;
+
+ bk.deleted = 1;
+ bk.type = B_KEYDATA;
+ bk.len = 0;
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.data = &bk;
+ hdr.size = SSZA(BKEYDATA, data);
+ memset(&data, 0, sizeof(data));
+ data.data = (char *) "";
+ data.size = 0;
+ if ((ret = __db_pitem(dbp,
+ h, indx, BKEYDATA_SIZE(0), &hdr, &data)) != 0)
+ goto err;
+
+ ++t->lstat.bt_deleted;
+ goto done;
+ }
+
+ /* Delete the item. */
+ if ((ret = __bam_ditem(dbp, h, indx)) != 0)
+ goto err;
+
+ ++t->lstat.bt_deleted;
+ if (t->bt_recno != NULL)
+ F_SET(t->bt_recno, RECNO_MODIFIED);
+
+ /* Adjust the counts. */
+ __bam_adjust(dbp, t, -1);
+
+ /* Adjust the cursors. */
+ __ram_ca(dbp, recno, CA_DELETE);
+
+ /*
+ * If the page is now empty, delete it -- we have the whole tree
+ * locked, so there are no preparations to make. Else, release
+ * the pages.
+ */
+ if (NUM_ENT(h) == 0 && h->pgno != PGNO_ROOT) {
+ stack = 0;
+ ret = __bam_dpages(dbp, t);
+ }
+
+done:
+err: if (stack)
+ __bam_stkrel(dbp);
+
+ PUTHANDLE(dbp);
+ return (ret);
+}
+
+/*
+ * __bam_ditem --
+ * Delete one or more entries from a page.
+ *
+ * PUBLIC: int __bam_ditem __P((DB *, PAGE *, u_int32_t));
+ */
+int
+__bam_ditem(dbp, h, indx)
+ DB *dbp;
+ PAGE *h;
+ u_int32_t indx;
+{
+ BINTERNAL *bi;
+ BKEYDATA *bk;
+ BOVERFLOW *bo;
+ u_int32_t nbytes;
+ int ret;
+
+ switch (TYPE(h)) {
+ case P_IBTREE:
+ bi = GET_BINTERNAL(h, indx);
+ switch (bi->type) {
+ case B_DUPLICATE:
+ case B_OVERFLOW:
+ nbytes = BINTERNAL_SIZE(bi->len);
+ goto offpage;
+ case B_KEYDATA:
+ nbytes = BKEYDATA_SIZE(bi->len);
+ break;
+ default:
+ return (__db_pgfmt(dbp, h->pgno));
+ }
+ break;
+ case P_IRECNO:
+ nbytes = RINTERNAL_SIZE;
+ break;
+ case P_LBTREE:
+ /*
+ * If it's a duplicate key, discard the index and don't touch
+ * the actual page item. This works because no data item can
+ * have an index that matches any other index so even if the
+ * data item is in an index "slot", it won't match any other
+ * index.
+ */
+ if (!(indx % 2)) {
+ if (indx > 0 && h->inp[indx] == h->inp[indx - P_INDX])
+ return (__bam_adjindx(dbp,
+ h, indx, indx - P_INDX, 0));
+ if (indx < (u_int32_t)(NUM_ENT(h) - P_INDX) &&
+ h->inp[indx] == h->inp[indx + P_INDX])
+ return (__bam_adjindx(dbp,
+ h, indx, indx + O_INDX, 0));
+ }
+ /* FALLTHROUGH */
+ case P_LRECNO:
+ bk = GET_BKEYDATA(h, indx);
+ switch (bk->type) {
+ case B_DUPLICATE:
+ case B_OVERFLOW:
+ nbytes = BOVERFLOW_SIZE;
+
+offpage: /* Delete duplicate/offpage chains. */
+ bo = GET_BOVERFLOW(h, indx);
+ if (bo->type == B_DUPLICATE) {
+ if ((ret =
+ __db_ddup(dbp, bo->pgno, __bam_free)) != 0)
+ return (ret);
+ } else
+ if ((ret =
+ __db_doff(dbp, bo->pgno, __bam_free)) != 0)
+ return (ret);
+ break;
+ case B_KEYDATA:
+ nbytes = BKEYDATA_SIZE(bk->len);
+ break;
+ default:
+ return (__db_pgfmt(dbp, h->pgno));
+ }
+ break;
+ default:
+ return (__db_pgfmt(dbp, h->pgno));
+ }
+
+ /* Delete the item. */
+ if ((ret = __db_ditem(dbp, h, indx, nbytes)) != 0)
+ return (ret);
+
+ /* Mark the page dirty. */
+ return (memp_fset(dbp->mpf, h, DB_MPOOL_DIRTY));
+}
+
+/*
+ * __bam_adjindx --
+ * Adjust an index on the page.
+ *
+ * PUBLIC: int __bam_adjindx __P((DB *, PAGE *, u_int32_t, u_int32_t, int));
+ */
+int
+__bam_adjindx(dbp, h, indx, indx_copy, is_insert)
+ DB *dbp;
+ PAGE *h;
+ u_int32_t indx, indx_copy;
+ int is_insert;
+{
+ db_indx_t copy;
+ int ret;
+
+ /* Log the change. */
+ if (DB_LOGGING(dbp) &&
+ (ret = __bam_adj_log(dbp->dbenv->lg_info, dbp->txn, &LSN(h),
+ 0, dbp->log_fileid, PGNO(h), &LSN(h), indx, indx_copy,
+ (u_int32_t)is_insert)) != 0)
+ return (ret);
+
+ if (is_insert) {
+ copy = h->inp[indx_copy];
+ if (indx != NUM_ENT(h))
+ memmove(&h->inp[indx + O_INDX], &h->inp[indx],
+ sizeof(db_indx_t) * (NUM_ENT(h) - indx));
+ h->inp[indx] = copy;
+ ++NUM_ENT(h);
+ } else {
+ --NUM_ENT(h);
+ if (indx != NUM_ENT(h))
+ memmove(&h->inp[indx], &h->inp[indx + O_INDX],
+ sizeof(db_indx_t) * (NUM_ENT(h) - indx));
+ }
+
+ /* Mark the page dirty. */
+ ret = memp_fset(dbp->mpf, h, DB_MPOOL_DIRTY);
+
+ /* Adjust the cursors. */
+ __bam_ca_di(dbp, h->pgno, indx, is_insert ? 1 : -1);
+ return (0);
+}
+
+/*
+ * __bam_dpage --
+ * Delete a page from the tree.
+ *
+ * PUBLIC: int __bam_dpage __P((DB *, const DBT *));
+ */
+int
+__bam_dpage(dbp, key)
+ DB *dbp;
+ const DBT *key;
+{
+ BTREE *t;
+ DB_LOCK lock;
+ PAGE *h;
+ db_pgno_t pgno;
+ int exact, level, ret;
+
+ ret = 0;
+ t = dbp->internal;
+
+ /*
+ * The locking protocol is that we acquire locks by walking down the
+ * tree, to avoid the obvious deadlocks.
+ *
+ * Call __bam_search to reacquire the empty leaf page, but this time
+ * get both the leaf page and it's parent, locked. Walk back up the
+ * tree, until we have the top pair of pages that we want to delete.
+ * Once we have the top page that we want to delete locked, lock the
+ * underlying pages and check to make sure they're still empty. If
+ * they are, delete them.
+ */
+ for (level = LEAFLEVEL;; ++level) {
+ /* Acquire a page and its parent, locked. */
+ if ((ret =
+ __bam_search(dbp, key, S_WRPAIR, level, NULL, &exact)) != 0)
+ return (ret);
+
+ /*
+ * If we reach the root or the page isn't going to be empty
+ * when we delete one record, quit.
+ */
+ h = t->bt_csp[-1].page;
+ if (h->pgno == PGNO_ROOT || NUM_ENT(h) != 1)
+ break;
+
+ /* Release the two locked pages. */
+ (void)memp_fput(dbp->mpf, t->bt_csp[-1].page, 0);
+ (void)__BT_TLPUT(dbp, t->bt_csp[-1].lock);
+ (void)memp_fput(dbp->mpf, t->bt_csp[0].page, 0);
+ (void)__BT_TLPUT(dbp, t->bt_csp[0].lock);
+ }
+
+ /*
+ * Leave the stack pointer one after the last entry, we may be about
+ * to push more items on the stack.
+ */
+ ++t->bt_csp;
+
+ /*
+ * t->bt_csp[-2].page is the top page, which we're not going to delete,
+ * and t->bt_csp[-1].page is the first page we are going to delete.
+ *
+ * Walk down the chain, acquiring the rest of the pages until we've
+ * retrieved the leaf page. If we find any pages that aren't going
+ * to be emptied by the delete, someone else added something while we
+ * were walking the tree, and we discontinue the delete.
+ */
+ for (h = t->bt_csp[-1].page;;) {
+ if (ISLEAF(h)) {
+ if (NUM_ENT(h) != 0)
+ goto release;
+ break;
+ } else
+ if (NUM_ENT(h) != 1)
+ goto release;
+
+ /*
+ * Get the next page, write lock it and push it onto the stack.
+ * We know it's index 0, because it can only have one element.
+ */
+ pgno = TYPE(h) == P_IBTREE ?
+ GET_BINTERNAL(h, 0)->pgno : GET_RINTERNAL(h, 0)->pgno;
+
+ if ((ret = __bam_lget(dbp, 0, pgno, DB_LOCK_WRITE, &lock)) != 0)
+ goto release;
+ if ((ret = __bam_pget(dbp, &h, &pgno, 0)) != 0)
+ goto release;
+ BT_STK_PUSH(t, h, 0, lock, ret);
+ if (ret != 0)
+ goto release;
+ }
+
+ BT_STK_POP(t);
+ return (__bam_dpages(dbp, t));
+
+release:
+ /* Discard any locked pages and return. */
+ BT_STK_POP(t);
+ __bam_stkrel(dbp);
+ return (ret);
+}
+
+/*
+ * __bam_dpages --
+ * Delete a set of locked pages.
+ */
+static int
+__bam_dpages(dbp, t)
+ DB *dbp;
+ BTREE *t;
+{
+ DBT a, b;
+ DB_LOCK lock;
+ EPG *epg;
+ PAGE *h;
+ db_pgno_t pgno;
+ db_recno_t rcnt;
+ int ret;
+
+ rcnt = 0; /* XXX: Shut the compiler up. */
+ epg = t->bt_sp;
+
+ /*
+ * !!!
+ * There is an interesting deadlock situation here. We have to relink
+ * the leaf page chain around the leaf page being deleted. Consider
+ * a cursor walking through the leaf pages, that has the previous page
+ * read-locked and is waiting on a lock for the page we're deleting.
+ * It will deadlock here. This is a problem, because if our process is
+ * selected to resolve the deadlock, we'll leave an empty leaf page
+ * that we can never again access by walking down the tree. So, before
+ * we unlink the subtree, we relink the leaf page chain.
+ */
+ if ((ret = __db_relink(dbp, t->bt_csp->page, NULL, 1)) != 0)
+ goto release;
+
+ /*
+ * We have the entire stack of deletable pages locked. Start from the
+ * top of the tree and move to the bottom, as it's better to release
+ * the inner pages as soon as possible.
+ */
+ if ((ret = __bam_ditem(dbp, epg->page, epg->indx)) != 0)
+ goto release;
+
+ /*
+ * If we deleted the next-to-last item from the root page, the tree
+ * has collapsed a level. Try and write lock the remaining root + 1
+ * page and copy it onto the root page. If we can't get the lock,
+ * that's okay, the tree just stays a level deeper than we'd like.
+ */
+ h = epg->page;
+ if (h->pgno == PGNO_ROOT && NUM_ENT(h) == 1) {
+ pgno = TYPE(epg->page) == P_IBTREE ?
+ GET_BINTERNAL(epg->page, 0)->pgno :
+ GET_RINTERNAL(epg->page, 0)->pgno;
+ if ((ret = __bam_lget(dbp, 0, pgno, DB_LOCK_WRITE, &lock)) != 0)
+ goto release;
+ if ((ret = __bam_pget(dbp, &h, &pgno, 0)) != 0)
+ goto release;
+
+ /* Log the change. */
+ if (DB_LOGGING(dbp)) {
+ memset(&a, 0, sizeof(a));
+ a.data = h;
+ a.size = dbp->pgsize;
+ memset(&b, 0, sizeof(b));
+ b.data = P_ENTRY(epg->page, 0);
+ b.size = BINTERNAL_SIZE(((BINTERNAL *)b.data)->len);
+ __bam_rsplit_log(dbp->dbenv->lg_info, dbp->txn,
+ &h->lsn, 0, dbp->log_fileid, h->pgno, &a, &b,
+ &epg->page->lsn);
+ }
+
+ /*
+ * Make the switch.
+ *
+ * One fixup -- if the tree has record numbers and we're not
+ * converting to a leaf page, we have to preserve the total
+ * record count.
+ */
+ if (TYPE(h) == P_IRECNO ||
+ (TYPE(h) == P_IBTREE && F_ISSET(dbp, DB_BT_RECNUM)))
+ rcnt = RE_NREC(epg->page);
+ memcpy(epg->page, h, dbp->pgsize);
+ epg->page->pgno = PGNO_ROOT;
+ if (TYPE(h) == P_IRECNO ||
+ (TYPE(h) == P_IBTREE && F_ISSET(dbp, DB_BT_RECNUM)))
+ RE_NREC_SET(epg->page, rcnt);
+
+ /* Free the last page in that level of the btree. */
+ ++t->lstat.bt_freed;
+ (void)__bam_free(dbp, h);
+
+ /* Adjust the cursors. */
+ __bam_ca_move(dbp, t, h->pgno, PGNO_ROOT);
+
+ (void)__BT_TLPUT(dbp, lock);
+ }
+
+ /* Release the top page in the subtree. */
+ (void)memp_fput(dbp->mpf, epg->page, 0);
+ (void)__BT_TLPUT(dbp, epg->lock);
+
+ /*
+ * Free the rest of the pages.
+ *
+ * XXX
+ * Don't bother checking for errors. We've unlinked the subtree from
+ * the tree, and there's no possibility of recovery.
+ */
+ for (; ++epg <= t->bt_csp; ++t->lstat.bt_freed) {
+ if (NUM_ENT(epg->page) != 0)
+ (void)__bam_ditem(dbp, epg->page, epg->indx);
+
+ (void)__bam_free(dbp, epg->page);
+ (void)__BT_TLPUT(dbp, epg->lock);
+ }
+ return (0);
+
+release:
+ /* Discard any remaining pages and return. */
+ for (; epg <= t->bt_csp; ++epg) {
+ (void)memp_fput(dbp->mpf, epg->page, 0);
+ (void)__BT_TLPUT(dbp, epg->lock);
+ }
+ return (ret);
+}