From 38e876d964346d3e4b88c52732b7ce5966d796a5 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Thu, 1 Nov 2018 13:35:40 +0100 Subject: import original 1.85 implementation from openbsd libc --- _db1.85/btree/bt_put.c | 310 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 310 insertions(+) create mode 100644 _db1.85/btree/bt_put.c (limited to '_db1.85/btree/bt_put.c') diff --git a/_db1.85/btree/bt_put.c b/_db1.85/btree/bt_put.c new file mode 100644 index 0000000..435ff18 --- /dev/null +++ b/_db1.85/btree/bt_put.c @@ -0,0 +1,310 @@ +/* $OpenBSD: bt_put.c,v 1.13 2005/08/05 13:02:59 espie Exp $ */ + +/*- + * Copyright (c) 1990, 1993, 1994 + * 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. 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 + +#include +#include +#include +#include + +#include +#include "btree.h" + +static EPG *bt_fast(BTREE *, const DBT *, const DBT *, int *); + +/* + * __BT_PUT -- Add a btree item to the tree. + * + * Parameters: + * dbp: pointer to access method + * key: key + * data: data + * flag: R_NOOVERWRITE + * + * Returns: + * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the + * tree and R_NOOVERWRITE specified. + */ +int +__bt_put(const DB *dbp, DBT *key, const DBT *data, u_int flags) +{ + BTREE *t; + DBT tkey, tdata; + EPG *e; + PAGE *h; + indx_t idx, nxtindex; + pgno_t pg; + u_int32_t nbytes, size32; + int dflags, exact, status; + char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; + + 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; + } + + /* Check for change to a read-only tree. */ + if (F_ISSET(t, B_RDONLY)) { + errno = EPERM; + return (RET_ERROR); + } + + switch (flags) { + case 0: + case R_NOOVERWRITE: + break; + case R_CURSOR: + /* + * If flags is R_CURSOR, put the cursor. Must already + * have started a scan and not have already deleted it. + */ + if (F_ISSET(&t->bt_cursor, CURS_INIT) && + !F_ISSET(&t->bt_cursor, + CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) + break; + /* FALLTHROUGH */ + default: + errno = EINVAL; + return (RET_ERROR); + } + + /* + * If the key/data pair won't fit on a page, store it on overflow + * pages. Only put the key on the overflow page if the pair are + * still too big after moving the data to an overflow page. + * + * XXX + * If the insert fails later on, the overflow pages aren't recovered. + */ + dflags = 0; + if (key->size + data->size > t->bt_ovflsize) { + if (key->size > t->bt_ovflsize) { +storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) + return (RET_ERROR); + tkey.data = kb; + tkey.size = NOVFLSIZE; + memmove(kb, &pg, sizeof(pgno_t)); + size32 = key->size; + memmove(kb + sizeof(pgno_t), + &size32, sizeof(u_int32_t)); + dflags |= P_BIGKEY; + key = &tkey; + } + if (key->size + data->size > t->bt_ovflsize) { + if (__ovfl_put(t, data, &pg) == RET_ERROR) + return (RET_ERROR); + tdata.data = db; + tdata.size = NOVFLSIZE; + memmove(db, &pg, sizeof(pgno_t)); + size32 = data->size; + memmove(db + sizeof(pgno_t), + &size32, sizeof(u_int32_t)); + dflags |= P_BIGDATA; + data = &tdata; + } + if (key->size + data->size > t->bt_ovflsize) + goto storekey; + } + + /* Replace the cursor. */ + if (flags == R_CURSOR) { + if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) + return (RET_ERROR); + idx = t->bt_cursor.pg.index; + goto delete; + } + + /* + * Find the key to delete, or, the location at which to insert. + * Bt_fast and __bt_search both pin the returned page. + */ + if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) + if ((e = __bt_search(t, key, &exact)) == NULL) + return (RET_ERROR); + h = e->page; + idx = e->index; + + /* + * Add the key/data pair to the tree. If an identical key is already + * in the tree, and R_NOOVERWRITE is set, an error is returned. If + * R_NOOVERWRITE is not set, the key is either added (if duplicates are + * permitted) or an error is returned. + */ + switch (flags) { + case R_NOOVERWRITE: + if (!exact) + break; + mpool_put(t->bt_mp, h, 0); + return (RET_SPECIAL); + default: + if (!exact || !F_ISSET(t, B_NODUPS)) + break; + /* + * !!! + * Note, the delete may empty the page, so we need to put a + * new entry into the page immediately. + */ +delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { + mpool_put(t->bt_mp, h, 0); + return (RET_ERROR); + } + break; + } + + /* + * If not enough room, or the user has put a ceiling on the number of + * keys permitted in the page, split the page. The split code will + * insert the key and data and unpin the current page. If inserting + * into the offset array, shift the pointers up. + */ + nbytes = NBLEAFDBT(key->size, data->size); + if (h->upper - h->lower < nbytes + sizeof(indx_t)) { + if ((status = __bt_split(t, h, key, + data, dflags, nbytes, idx)) != RET_SUCCESS) + return (status); + goto success; + } + + if (idx < (nxtindex = NEXTINDEX(h))) + memmove(h->linp + idx + 1, h->linp + idx, + (nxtindex - idx) * sizeof(indx_t)); + h->lower += sizeof(indx_t); + + h->linp[idx] = h->upper -= nbytes; + dest = (char *)h + h->upper; + WR_BLEAF(dest, key, data, dflags); + + /* If the cursor is on this page, adjust it as necessary. */ + if (F_ISSET(&t->bt_cursor, CURS_INIT) && + !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && + t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) + ++t->bt_cursor.pg.index; + + if (t->bt_order == NOT) { + if (h->nextpg == P_INVALID) { + if (idx == NEXTINDEX(h) - 1) { + t->bt_order = FORWARD; + t->bt_last.index = idx; + t->bt_last.pgno = h->pgno; + } + } else if (h->prevpg == P_INVALID) { + if (idx == 0) { + t->bt_order = BACK; + t->bt_last.index = 0; + t->bt_last.pgno = h->pgno; + } + } + } + + mpool_put(t->bt_mp, h, MPOOL_DIRTY); + +success: + if (flags == R_SETCURSOR) + __bt_setcur(t, e->page->pgno, e->index); + + F_SET(t, B_MODIFIED); + return (RET_SUCCESS); +} + +#ifdef STATISTICS +u_long bt_cache_hit, bt_cache_miss; +#endif + +/* + * BT_FAST -- Do a quick check for sorted data. + * + * Parameters: + * t: tree + * key: key to insert + * + * Returns: + * EPG for new record or NULL if not found. + */ +static EPG * +bt_fast(BTREE *t, const DBT *key, const DBT *data, int *exactp) +{ + PAGE *h; + u_int32_t nbytes; + int cmp; + + if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { + t->bt_order = NOT; + return (NULL); + } + t->bt_cur.page = h; + t->bt_cur.index = t->bt_last.index; + + /* + * If won't fit in this page or have too many keys in this page, + * have to search to get split stack. + */ + nbytes = NBLEAFDBT(key->size, data->size); + if (h->upper - h->lower < nbytes + sizeof(indx_t)) + goto miss; + + if (t->bt_order == FORWARD) { + if (t->bt_cur.page->nextpg != P_INVALID) + goto miss; + if (t->bt_cur.index != NEXTINDEX(h) - 1) + goto miss; + if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) + goto miss; + t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; + } else { + if (t->bt_cur.page->prevpg != P_INVALID) + goto miss; + if (t->bt_cur.index != 0) + goto miss; + if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) + goto miss; + t->bt_last.index = 0; + } + *exactp = cmp == 0; +#ifdef STATISTICS + ++bt_cache_hit; +#endif + return (&t->bt_cur); + +miss: +#ifdef STATISTICS + ++bt_cache_miss; +#endif + t->bt_order = NOT; + mpool_put(t->bt_mp, h, 0); + return (NULL); +} -- cgit v1.2.3