diff options
Diffstat (limited to 'db2/btree/bt_put.c')
| -rw-r--r-- | db2/btree/bt_put.c | 919 |
1 files changed, 919 insertions, 0 deletions
diff --git a/db2/btree/bt_put.c b/db2/btree/bt_put.c new file mode 100644 index 0000000000..632c3d185b --- /dev/null +++ b/db2/btree/bt_put.c @@ -0,0 +1,919 @@ +/*- + * 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_put.c 10.23 (Sleepycat) 8/22/97"; +#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 "btree.h" + +static int __bam_fixed __P((BTREE *, DBT *)); +static int __bam_lookup __P((DB *, DBT *, int *)); +static int __bam_ndup __P((DB *, PAGE *, u_int32_t)); +static int __bam_partial __P((DB *, DBT *, PAGE *, u_int32_t)); + +/* + * __bam_put -- + * Add a new key/data pair or replace an existing pair (btree). + * + * PUBLIC: int __bam_put __P((DB *, DB_TXN *, DBT *, DBT *, int)); + */ +int +__bam_put(argdbp, txn, key, data, flags) + DB *argdbp; + DB_TXN *txn; + DBT *key, *data; + int flags; +{ + BTREE *t; + CURSOR c; + DB *dbp; + PAGE *h; + db_indx_t indx; + int exact, iflags, newkey, replace, ret, stack; + + DEBUG_LWRITE(argdbp, txn, "bam_put", key, data, flags); + + /* Check flags. */ + if ((ret = __db_putchk(argdbp, key, data, flags, + F_ISSET(argdbp, DB_AM_RDONLY), F_ISSET(argdbp, DB_AM_DUP))) != 0) + return (ret); + + GETHANDLE(argdbp, txn, &dbp, ret); + t = dbp->internal; + +retry: /* + * Find the location at which to insert. The call to bt_lookup() + * leaves the returned page pinned. + */ + if ((ret = __bam_lookup(dbp, key, &exact)) != 0) { + PUTHANDLE(dbp); + return (ret); + } + h = t->bt_csp->page; + indx = t->bt_csp->indx; + stack = 1; + + /* + * If an identical key is already in the tree, and DB_NOOVERWRITE is + * set, an error is returned. If an identical key is already in the + * tree and DB_NOOVERWRITE is not set, the key is either added (when + * duplicates are permitted) or an error is returned. The exception + * is when the item located is referenced by a cursor and marked for + * deletion, in which case we permit the overwrite and flag the cursor. + */ + replace = 0; + if (exact && flags == DB_NOOVERWRITE) { + if (!GET_BKEYDATA(h, indx + O_INDX)->deleted) { + ret = DB_KEYEXIST; + goto err; + } + replace = 1; + __bam_ca_replace(dbp, h->pgno, indx, REPLACE_SETUP); + } + + /* + * If we're inserting into the first or last page of the tree, + * remember where we did it so we can do fast lookup next time. + * + * XXX + * Does reverse order still work (did it ever!?!?) + */ + t->bt_lpgno = + h->next_pgno == PGNO_INVALID || h->prev_pgno == PGNO_INVALID ? + h->pgno : PGNO_INVALID; + + /* + * Select the arguments for __bam_iitem() and do the insert. If the + * key is an exact match, we're either adding a new duplicate at the + * end of the duplicate set, 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. + */ + newkey = dbp->type == DB_BTREE && !exact; + if (exact) { + if (F_ISSET(dbp, DB_AM_DUP)) { + /* + * Make sure that we're not looking at a page of + * duplicates -- if so, move to the last entry on + * that page. + */ + c.page = h; + c.pgno = h->pgno; + c.indx = indx; + c.dpgno = PGNO_INVALID; + c.dindx = 0; + if ((ret = + __bam_ovfl_chk(dbp, &c, indx + O_INDX, 1)) != 0) + goto err; + if (c.dpgno != PGNO_INVALID) { + /* + * XXX + * The __bam_ovfl_chk() routine memp_fput() the + * current page and acquired a new one, but did + * not do anything about the lock we're holding. + */ + t->bt_csp->page = h = c.page; + indx = c.dindx; + } + iflags = DB_AFTER; + } else + iflags = DB_CURRENT; + } else + iflags = DB_BEFORE; + + /* + * The pages we're using may be modified by __bam_iitem(), so make + * sure we reset the stack. + */ + ret = __bam_iitem(dbp, + &h, &indx, key, data, iflags, newkey ? BI_NEWKEY : 0); + t->bt_csp->page = h; + t->bt_csp->indx = indx; + + switch (ret) { + case 0: + /* + * Done. Clean up the cursor, and, if we're doing record + * numbers, adjust the internal page counts. + */ + if (replace) + __bam_ca_replace(dbp, h->pgno, indx, REPLACE_SUCCESS); + + if (!replace && F_ISSET(dbp, DB_BT_RECNUM)) + ret = __bam_adjust(dbp, t, 1); + break; + case DB_NEEDSPLIT: + /* + * We have to split the page. Back out the cursor setup, + * discard the stack of pages, and do the split. + */ + if (replace) { + replace = 0; + __bam_ca_replace(dbp, h->pgno, indx, REPLACE_FAILED); + } + + (void)__bam_stkrel(dbp); + stack = 0; + + if ((ret = __bam_split(dbp, key)) != 0) + break; + + goto retry; + /* NOTREACHED */ + default: + if (replace) + __bam_ca_replace(dbp, h->pgno, indx, REPLACE_FAILED); + break; + } + +err: if (stack) + (void)__bam_stkrel(dbp); + + PUTHANDLE(dbp); + return (ret); +} + +/* + * __bam_lookup -- + * Find the right location in the tree for the key. + */ +static int +__bam_lookup(dbp, key, exactp) + DB *dbp; + DBT *key; + int *exactp; +{ + BTREE *t; + DB_LOCK lock; + EPG e; + PAGE *h; + db_indx_t indx; + int cmp, ret; + + t = dbp->internal; + h = NULL; + + /* + * Record numbers can't be fast-tracked, we have to lock the entire + * tree. + */ + if (F_ISSET(dbp, DB_BT_RECNUM)) + goto slow; + + /* Check to see if we've been seeing sorted input. */ + if (t->bt_lpgno == PGNO_INVALID) + goto slow; + + /* + * Retrieve the page on which we did the last insert. It's okay if + * it doesn't exist, or if it's not the page type we expect, it just + * means that the world changed. + */ + if (__bam_lget(dbp, 0, t->bt_lpgno, DB_LOCK_WRITE, &lock)) + goto miss; + if (__bam_pget(dbp, &h, &t->bt_lpgno, 0)) { + (void)__BT_LPUT(dbp, lock); + goto miss; + } + if (TYPE(h) != P_LBTREE) + goto miss; + if (NUM_ENT(h) == 0) + goto miss; + + /* + * We have to be at the end or beginning of the tree to know that + * we're inserting in a sort order. If that's the case and we're + * in the right order in comparison to the first/last key/data pair, + * we have the right position. + */ + if (h->next_pgno == PGNO_INVALID) { + e.page = h; + e.indx = NUM_ENT(h) - P_INDX; + if ((cmp = __bam_cmp(dbp, key, &e)) >= 0) { + if (cmp > 0) + e.indx += P_INDX; + goto fast; + } + } + if (h->prev_pgno == PGNO_INVALID) { + e.page = h; + e.indx = 0; + if ((cmp = __bam_cmp(dbp, key, &e)) <= 0) { + /* + * We're doing a put, so we want to insert as the last + * of any set of duplicates. + */ + if (cmp == 0) { + for (indx = 0; + indx < (db_indx_t)(NUM_ENT(h) - P_INDX) && + h->inp[indx] == h->inp[indx + P_INDX]; + indx += P_INDX); + e.indx = indx; + } + goto fast; + } + } + goto miss; + + /* Set the exact match flag in case we've already inserted this key. */ +fast: *exactp = cmp == 0; + + /* Enter the entry in the stack. */ + BT_STK_CLR(t); + BT_STK_ENTER(t, e.page, e.indx, lock, ret); + if (ret != 0) + return (ret); + + ++t->lstat.bt_cache_hit; + return (0); + +miss: ++t->lstat.bt_cache_miss; + if (h != NULL) { + (void)memp_fput(dbp->mpf, h, 0); + (void)__BT_LPUT(dbp, lock); + } + +slow: return (__bam_search(dbp, key, S_INSERT, 1, NULL, exactp)); +} + +/* + * OVPUT -- + * Copy an overflow item onto a page. + */ +#undef OVPUT +#define OVPUT(h, indx, bo) do { \ + DBT __hdr; \ + memset(&__hdr, 0, sizeof(__hdr)); \ + __hdr.data = &bo; \ + __hdr.size = BOVERFLOW_SIZE; \ + if ((ret = __db_pitem(dbp, \ + h, indx, BOVERFLOW_SIZE, &__hdr, NULL)) != 0) \ + return (ret); \ +} while (0) + +/* + * __bam_iitem -- + * Insert an item into the tree. + * + * PUBLIC: int __bam_iitem __P((DB *, + * PUBLIC: PAGE **, db_indx_t *, DBT *, DBT *, int, int)); + */ +int +__bam_iitem(dbp, hp, indxp, key, data, op, flags) + DB *dbp; + PAGE **hp; + db_indx_t *indxp; + DBT *key, *data; + int op, flags; +{ + BTREE *t; + BKEYDATA *bk; + BOVERFLOW kbo, dbo; + DBT tdbt; + PAGE *h; + db_indx_t indx; + u_int32_t have_bytes, need_bytes, needed; + int bigkey, bigdata, dcopy, dupadjust, ret; + + t = dbp->internal; + h = *hp; + indx = *indxp; + + dupadjust = 0; + bk = NULL; /* XXX: Shut the compiler up. */ + + /* + * If it's a page of duplicates, call the common code to do the work. + * + * !!! + * Here's where the hp and indxp are important. The duplicate code + * may decide to rework/rearrange the pages and indices we're using, + * so the caller must understand that the stack has to change. + */ + if (TYPE(h) == P_DUPLICATE) { + /* Adjust the index for the new item if it's a DB_AFTER op. */ + if (op == DB_AFTER) + ++*indxp; + + /* Remove the current item if it's a DB_CURRENT op. */ + if (op == DB_CURRENT && (ret = __db_ditem(dbp, *hp, *indxp, + BKEYDATA_SIZE(GET_BKEYDATA(*hp, *indxp)->len))) != 0) + return (ret); + + /* Put the new/replacement item onto the page. */ + return (__db_dput(dbp, data, hp, indxp, __bam_new)); + } + + /* + * XXX + * Handle partial puts. + * + * This is truly awful from a performance standput. We don't optimize + * for partial puts at all, we delete the record and add it back in, + * regardless of size or if we're simply overwriting current data. + * The hash access method does this a lot better than we do, and we're + * eventually going to have to fix it. + */ + if (F_ISSET(data, DB_DBT_PARTIAL)) { + tdbt = *data; + if ((ret = __bam_partial(dbp, &tdbt, h, indx)) != 0) + return (ret); + data = &tdbt; + } + + /* If it's a short fixed-length record, fix it up. */ + if (F_ISSET(dbp, DB_RE_FIXEDLEN) && data->size != t->bt_recno->re_len) { + tdbt = *data; + if ((ret = __bam_fixed(t, &tdbt)) != 0) + return (ret); + data = &tdbt; + } + + /* + * If the key or data item won't fit on a page, store it in the + * overflow pages. + * + * !!! + * From this point on, we have to recover the allocated overflow + * pages on error. + */ + bigkey = bigdata = 0; + if (LF_ISSET(BI_NEWKEY) && key->size > t->bt_ovflsize) { + kbo.deleted = 0; + kbo.type = B_OVERFLOW; + kbo.tlen = key->size; + if ((ret = __db_poff(dbp, key, &kbo.pgno, __bam_new)) != 0) + goto err; + bigkey = 1; + } + if (data->size > t->bt_ovflsize) { + dbo.deleted = 0; + dbo.type = B_OVERFLOW; + dbo.tlen = data->size; + if ((ret = __db_poff(dbp, data, &dbo.pgno, __bam_new)) != 0) + goto err; + bigdata = 1; + } + + dcopy = 0; + needed = 0; + if (LF_ISSET(BI_NEWKEY)) { + /* If BI_NEWKEY is set we're adding a new key and data pair. */ + if (bigkey) + needed += BOVERFLOW_PSIZE; + else + needed += BKEYDATA_PSIZE(key->size); + if (bigdata) + needed += BOVERFLOW_PSIZE; + else + needed += BKEYDATA_PSIZE(data->size); + } else { + /* + * We're either overwriting the data item of a key/data pair + * or we're adding the data item only, i.e. a new duplicate. + */ + if (op == DB_CURRENT) { + bk = GET_BKEYDATA(h, + indx + (TYPE(h) == P_LBTREE ? O_INDX : 0)); + if (bk->type == B_OVERFLOW) + have_bytes = BOVERFLOW_PSIZE; + else + have_bytes = BKEYDATA_PSIZE(bk->len); + need_bytes = 0; + } else { + have_bytes = 0; + need_bytes = sizeof(db_indx_t); + } + if (bigdata) + need_bytes += BOVERFLOW_PSIZE; + else + need_bytes += BKEYDATA_PSIZE(data->size); + + /* + * If we're overwriting a data item, we copy it if it's not a + * special record type and it's the same size (including any + * alignment) and do a delete/insert otherwise. + */ + if (op == DB_CURRENT && !bigdata && + bk->type == B_KEYDATA && have_bytes == need_bytes) + dcopy = 1; + if (have_bytes < need_bytes) + needed += need_bytes - have_bytes; + } + + /* + * If there's not enough room, or the user has put a ceiling on the + * number of keys permitted in the page, split the page. + * + * XXX + * The t->bt_maxkey test here may be insufficient -- do we have to + * check in the btree split code, so we don't undo it there!?!? + */ + if (P_FREESPACE(h) < needed || + (t->bt_maxkey != 0 && NUM_ENT(h) > t->bt_maxkey)) { + ret = DB_NEEDSPLIT; + goto err; + } + + /* + * The code breaks it up into six cases: + * + * 1. Append a new key/data pair. + * 2. Insert a new key/data pair. + * 3. Copy the data item. + * 4. Delete/insert the data item. + * 5. Append a new data item. + * 6. Insert a new data item. + */ + if (LF_ISSET(BI_NEWKEY)) { + switch (op) { + case DB_AFTER: /* 1. Append a new key/data pair. */ + indx += 2; + *indxp += 2; + break; + case DB_BEFORE: /* 2. Insert a new key/data pair. */ + break; + default: + abort(); + } + + /* Add the key. */ + if (bigkey) + OVPUT(h, indx, kbo); + else { + DBT __data; + memset(&__data, 0, sizeof(__data)); + __data.data = key->data; + __data.size = key->size; + if ((ret = __db_pitem(dbp, h, indx, + BKEYDATA_SIZE(key->size), NULL, &__data)) != 0) + goto err; + } + ++indx; + } else { + switch (op) { + case DB_CURRENT: /* 3. Copy the data item. */ + /* + * If we're not logging and it's possible, overwrite + * the current item. + * + * XXX + * We should add a separate logging message so that + * we can do this anytime it's possible, including + * for partial record puts. + */ + if (dcopy && !DB_LOGGING(dbp)) { + bk->len = data->size; + memcpy(bk->data, data->data, data->size); + goto done; + } + /* 4. Delete/insert the data item. */ + if (TYPE(h) == P_LBTREE) + ++indx; + if ((ret = __bam_ditem(dbp, h, indx)) != 0) + goto err; + break; + case DB_AFTER: /* 5. Append a new data item. */ + if (TYPE(h) == P_LBTREE) { + /* + * Adjust the cursor and copy in the key for + * the duplicate. + */ + if ((ret = __bam_adjindx(dbp, + h, indx + P_INDX, indx, 1)) != 0) + goto err; + + indx += 3; + dupadjust = 1; + + *indxp += 2; + } else { + ++indx; + __bam_ca_di(dbp, h->pgno, indx, 1); + + *indxp += 1; + } + break; + case DB_BEFORE: /* 6. Insert a new data item. */ + if (TYPE(h) == P_LBTREE) { + /* + * Adjust the cursor and copy in the key for + * the duplicate. + */ + if ((ret = + __bam_adjindx(dbp, h, indx, indx, 1)) != 0) + goto err; + + ++indx; + dupadjust = 1; + } else + __bam_ca_di(dbp, h->pgno, indx, 1); + break; + default: + abort(); + } + } + + /* Add the data. */ + if (bigdata) + OVPUT(h, indx, dbo); + else { + BKEYDATA __bk; + DBT __hdr, __data; + memset(&__data, 0, sizeof(__data)); + __data.data = data->data; + __data.size = data->size; + + if (LF_ISSET(BI_DELETED)) { + __bk.len = __data.size; + __bk.deleted = 1; + __bk.type = B_KEYDATA; + __hdr.data = &__bk; + __hdr.size = SSZA(BKEYDATA, data); + ret = __db_pitem(dbp, h, indx, + BKEYDATA_SIZE(__data.size), &__hdr, &__data); + } else + ret = __db_pitem(dbp, h, indx, + BKEYDATA_SIZE(data->size), NULL, &__data); + if (ret != 0) + goto err; + } + +done: ++t->lstat.bt_added; + + ret = memp_fset(dbp->mpf, h, DB_MPOOL_DIRTY); + + /* + * If the page is at least 50% full, and we added a duplicate, see if + * that set of duplicates takes up at least 25% of the space. If it + * does, move it off onto its own page. + */ + if (dupadjust && P_FREESPACE(h) <= dbp->pgsize / 2) { + --indx; + if ((ret = __bam_ndup(dbp, h, indx)) != 0) + goto err; + } + + if (t->bt_recno != NULL) + F_SET(t->bt_recno, RECNO_MODIFIED); + + if (0) { +err: if (bigkey) + (void)__db_doff(dbp, kbo.pgno, __bam_free); + if (bigdata) + (void)__db_doff(dbp, dbo.pgno, __bam_free); + } + return (ret); +} + +/* + * __bam_ndup -- + * Check to see if the duplicate set at indx should have its own page. + * If it should, create it. + */ +static int +__bam_ndup(dbp, h, indx) + DB *dbp; + PAGE *h; + u_int32_t indx; +{ + BKEYDATA *bk; + BOVERFLOW bo; + DBT hdr; + PAGE *cp; + db_indx_t cnt, cpindx, first, sz; + int ret; + + while (indx > 0 && h->inp[indx] == h->inp[indx - P_INDX]) + indx -= P_INDX; + for (cnt = 0, sz = 0, first = indx;; ++cnt, indx += P_INDX) { + if (indx >= NUM_ENT(h) || h->inp[first] != h->inp[indx]) + break; + bk = GET_BKEYDATA(h, indx); + sz += bk->type == B_KEYDATA ? + BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE; + bk = GET_BKEYDATA(h, indx + O_INDX); + sz += bk->type == B_KEYDATA ? + BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE; + } + + /* + * If this set of duplicates is using more than 25% of the page, move + * them off. The choice of 25% is a WAG, but it has to be small enough + * that we can always split regardless of the presence of duplicates. + */ + if (sz < dbp->pgsize / 4) + return (0); + + /* Get a new page. */ + if ((ret = __bam_new(dbp, P_DUPLICATE, &cp)) != 0) + return (ret); + + /* + * Move this set of duplicates off the page. First points to the first + * key of the first duplicate key/data pair, cnt is the number of pairs + * we're dealing with. + */ + memset(&hdr, 0, sizeof(hdr)); + for (indx = first + O_INDX, cpindx = 0;; ++cpindx) { + /* Copy the entry to the new page. */ + bk = GET_BKEYDATA(h, indx); + hdr.data = bk; + hdr.size = bk->type == B_KEYDATA ? + BKEYDATA_SIZE(bk->len) : BOVERFLOW_SIZE; + if ((ret = + __db_pitem(dbp, cp, cpindx, hdr.size, &hdr, NULL)) != 0) + goto err; + + /* + * Move cursors referencing the old entry to the new entry. + * Done after the page put because __db_pitem() adjusts + * cursors on the new page, and before the delete because + * __db_ditem adjusts cursors on the old page. + */ + __bam_ca_dup(dbp, + PGNO(h), first, indx - O_INDX, PGNO(cp), cpindx); + + /* Delete the data item. */ + if ((ret = __db_ditem(dbp, h, indx, hdr.size)) != 0) + goto err; + + /* Delete all but the first reference to the key. */ + if (--cnt == 0) + break; + if ((ret = __bam_adjindx(dbp, h, indx, first, 0)) != 0) + goto err; + } + + /* Put in a new data item that points to the duplicates page. */ + bo.deleted = 0; + bo.type = B_DUPLICATE; + bo.pgno = cp->pgno; + bo.tlen = 0; + + OVPUT(h, indx, bo); + + return (memp_fput(dbp->mpf, cp, DB_MPOOL_DIRTY)); + +err: (void)__bam_free(dbp, cp); + return (ret); +} + +/* + * __bam_fixed -- + * Build the real record for a fixed length put. + */ +static int +__bam_fixed(t, dbt) + BTREE *t; + DBT *dbt; +{ + RECNO *rp; + + rp = t->bt_recno; + + /* + * If using fixed-length records, and the record is long, return + * EINVAL. If it's short, pad it out. Use the record data return + * memory, it's only short-term. + */ + if (dbt->size > rp->re_len) + return (EINVAL); + 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; + } + memcpy(t->bt_rdata.data, dbt->data, dbt->size); + memset((u_int8_t *)t->bt_rdata.data + dbt->size, + rp->re_pad, rp->re_len - dbt->size); + + /* Set the DBT to reference our new record. */ + t->bt_rdata.size = rp->re_len; + t->bt_rdata.dlen = 0; + t->bt_rdata.doff = 0; + t->bt_rdata.flags = 0; + *dbt = t->bt_rdata; + return (0); +} + +/* + * __bam_partial -- + * Build the real record for a partial put. + */ +static int +__bam_partial(dbp, dbt, h, indx) + DB *dbp; + DBT *dbt; + PAGE *h; + u_int32_t indx; +{ + BTREE *t; + BKEYDATA *bk, tbk; + BOVERFLOW *bo; + DBT copy; + u_int32_t len, nbytes, tlen; + int ret; + u_int8_t *p; + + bo = NULL; /* XXX: Shut the compiler up. */ + t = dbp->internal; + + /* + * Figure out how much total space we'll need. Worst case is where + * the record is 0 bytes long, in which case doff causes the record + * to extend, and the put data is appended to it. + */ + if (indx < NUM_ENT(h)) { + bk = GET_BKEYDATA(h, indx + (TYPE(h) == P_LBTREE ? O_INDX : 0)); + if (bk->type == B_OVERFLOW) { + bo = (BOVERFLOW *)bk; + nbytes = bo->tlen; + } else + nbytes = bk->len; + } else { + bk = &tbk; + bk->type = B_KEYDATA; + nbytes = bk->len = 0; + } + nbytes += dbt->doff + dbt->size + dbt->dlen; + + /* Allocate the space. */ + if (t->bt_rdata.ulen < nbytes) { + t->bt_rdata.data = t->bt_rdata.data == NULL ? + (void *)malloc(nbytes) : + (void *)realloc(t->bt_rdata.data, nbytes); + if (t->bt_rdata.data == NULL) { + t->bt_rdata.ulen = 0; + return (ENOMEM); + } + t->bt_rdata.ulen = nbytes; + } + + /* We use nul bytes for extending the record, get it over with. */ + memset(t->bt_rdata.data, 0, nbytes); + + tlen = 0; + if (bk->type == B_OVERFLOW) { + /* Take up to doff bytes from the record. */ + memset(©, 0, sizeof(copy)); + if ((ret = __db_goff(dbp, ©, bo->tlen, + bo->pgno, &t->bt_rdata.data, &t->bt_rdata.ulen)) != 0) + return (ret); + tlen += dbt->doff; + + /* + * If the original record was larger than the offset: + * If dlen > size, shift the remaining data down. + * If dlen < size, shift the remaining data up. + * Use memmove(), the regions may overlap. + */ + p = t->bt_rdata.data; + if (bo->tlen > dbt->doff) + if (dbt->dlen > dbt->size) { + tlen += len = bo->tlen - + dbt->doff - (dbt->dlen - dbt->size); + memmove(p + dbt->doff + dbt->size, + p + dbt->doff + dbt->dlen, len); + } else if (dbt->dlen < dbt->size) { + tlen += len = bo->tlen - + dbt->doff - (dbt->size - dbt->dlen); + memmove(p + dbt->doff + dbt->dlen, + p + dbt->doff + dbt->size, len); + } else + tlen += bo->tlen - dbt->doff; + + /* Copy in the user's data. */ + memcpy((u_int8_t *)t->bt_rdata.data + dbt->doff, + dbt->data, dbt->size); + tlen += dbt->size; + } else { + /* Take up to doff bytes from the record. */ + memcpy(t->bt_rdata.data, + bk->data, dbt->doff > bk->len ? bk->len : dbt->doff); + tlen += dbt->doff; + + /* Copy in the user's data. */ + memcpy((u_int8_t *)t->bt_rdata.data + + dbt->doff, dbt->data, dbt->size); + tlen += dbt->size; + + /* Copy in any remaining data. */ + len = dbt->doff + dbt->dlen; + if (bk->len > len) { + memcpy((u_int8_t *)t->bt_rdata.data + dbt->doff + + dbt->size, bk->data + len, bk->len - len); + tlen += bk->len - len; + } + } + + /* Set the DBT to reference our new record. */ + t->bt_rdata.size = tlen; + t->bt_rdata.dlen = 0; + t->bt_rdata.doff = 0; + t->bt_rdata.flags = 0; + *dbt = t->bt_rdata; + return (0); +} |