/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996, 1997, 1998, 1999, 2000 * Sleepycat Software. All rights reserved. */ /* * Copyright (c) 1990, 1993, 1994 * Margo Seltzer. All rights reserved. */ /* * 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 * Margo Seltzer. * * 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 "db_config.h" #ifndef lint static const char revid[] = "$Id: hash_page.c,v 11.46 2001/01/11 18:19:51 bostic Exp $"; #endif /* not lint */ /* * PACKAGE: hashing * * DESCRIPTION: * Page manipulation for hashing package. * * ROUTINES: * * External * __get_page * __add_ovflpage * __overflow_page * Internal * open_temp */ #ifndef NO_SYSTEM_INCLUDES #include #include #endif #include "db_int.h" #include "db_page.h" #include "db_shash.h" #include "hash.h" #include "lock.h" #include "txn.h" /* * PUBLIC: int __ham_item __P((DBC *, db_lockmode_t, db_pgno_t *)); */ int __ham_item(dbc, mode, pgnop) DBC *dbc; db_lockmode_t mode; db_pgno_t *pgnop; { DB *dbp; HASH_CURSOR *hcp; db_pgno_t next_pgno; int ret; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; if (F_ISSET(hcp, H_DELETED)) { __db_err(dbp->dbenv, "Attempt to return a deleted item"); return (EINVAL); } F_CLR(hcp, H_OK | H_NOMORE); /* Check if we need to get a page for this cursor. */ if ((ret = __ham_get_cpage(dbc, mode)) != 0) return (ret); recheck: /* Check if we are looking for space in which to insert an item. */ if (hcp->seek_size && hcp->seek_found_page == PGNO_INVALID && hcp->seek_size < P_FREESPACE(hcp->page)) hcp->seek_found_page = hcp->pgno; /* Check for off-page duplicates. */ if (hcp->indx < NUM_ENT(hcp->page) && HPAGE_TYPE(hcp->page, H_DATAINDEX(hcp->indx)) == H_OFFDUP) { memcpy(pgnop, HOFFDUP_PGNO(H_PAIRDATA(hcp->page, hcp->indx)), sizeof(db_pgno_t)); F_SET(hcp, H_OK); return (0); } /* Check if we need to go on to the next page. */ if (F_ISSET(hcp, H_ISDUP)) /* * ISDUP is set, and offset is at the beginning of the datum. * We need to grab the length of the datum, then set the datum * pointer to be the beginning of the datum. */ memcpy(&hcp->dup_len, HKEYDATA_DATA(H_PAIRDATA(hcp->page, hcp->indx)) + hcp->dup_off, sizeof(db_indx_t)); if (hcp->indx >= (db_indx_t)NUM_ENT(hcp->page)) { /* Fetch next page. */ if (NEXT_PGNO(hcp->page) == PGNO_INVALID) { F_SET(hcp, H_NOMORE); return (DB_NOTFOUND); } next_pgno = NEXT_PGNO(hcp->page); hcp->indx = 0; if ((ret = __ham_next_cpage(dbc, next_pgno, 0)) != 0) return (ret); goto recheck; } F_SET(hcp, H_OK); return (0); } /* * PUBLIC: int __ham_item_reset __P((DBC *)); */ int __ham_item_reset(dbc) DBC *dbc; { HASH_CURSOR *hcp; DB *dbp; int ret; ret = 0; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; if (hcp->page != NULL) ret = memp_fput(dbp->mpf, hcp->page, 0); __ham_item_init(dbc); return (ret); } /* * PUBLIC: void __ham_item_init __P((DBC *)); */ void __ham_item_init(dbc) DBC *dbc; { HASH_CURSOR *hcp; hcp = (HASH_CURSOR *)dbc->internal; /* * If this cursor still holds any locks, we must * release them if we are not running with transactions. */ if (hcp->lock.off != LOCK_INVALID && dbc->txn == NULL) (void)lock_put(dbc->dbp->dbenv, &hcp->lock); /* * The following fields must *not* be initialized here * because they may have meaning across inits. * hlock, hdr, split_buf, stats */ hcp->bucket = BUCKET_INVALID; hcp->lbucket = BUCKET_INVALID; hcp->lock.off = LOCK_INVALID; hcp->lock_mode = DB_LOCK_NG; hcp->dup_off = 0; hcp->dup_len = 0; hcp->dup_tlen = 0; hcp->seek_size = 0; hcp->seek_found_page = PGNO_INVALID; hcp->flags = 0; hcp->pgno = PGNO_INVALID; hcp->indx = NDX_INVALID; hcp->page = NULL; } /* * Returns the last item in a bucket. * * PUBLIC: int __ham_item_last __P((DBC *, db_lockmode_t, db_pgno_t *)); */ int __ham_item_last(dbc, mode, pgnop) DBC *dbc; db_lockmode_t mode; db_pgno_t *pgnop; { HASH_CURSOR *hcp; int ret; hcp = (HASH_CURSOR *)dbc->internal; if ((ret = __ham_item_reset(dbc)) != 0) return (ret); hcp->bucket = hcp->hdr->max_bucket; hcp->pgno = BUCKET_TO_PAGE(hcp, hcp->bucket); F_SET(hcp, H_OK); return (__ham_item_prev(dbc, mode, pgnop)); } /* * PUBLIC: int __ham_item_first __P((DBC *, db_lockmode_t, db_pgno_t *)); */ int __ham_item_first(dbc, mode, pgnop) DBC *dbc; db_lockmode_t mode; db_pgno_t *pgnop; { HASH_CURSOR *hcp; int ret; hcp = (HASH_CURSOR *)dbc->internal; if ((ret = __ham_item_reset(dbc)) != 0) return (ret); F_SET(hcp, H_OK); hcp->bucket = 0; hcp->pgno = BUCKET_TO_PAGE(hcp, hcp->bucket); return (__ham_item_next(dbc, mode, pgnop)); } /* * __ham_item_prev -- * Returns a pointer to key/data pair on a page. In the case of * bigkeys, just returns the page number and index of the bigkey * pointer pair. * * PUBLIC: int __ham_item_prev __P((DBC *, db_lockmode_t, db_pgno_t *)); */ int __ham_item_prev(dbc, mode, pgnop) DBC *dbc; db_lockmode_t mode; db_pgno_t *pgnop; { DB *dbp; HASH_CURSOR *hcp; db_pgno_t next_pgno; int ret; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; /* * There are 5 cases for backing up in a hash file. * Case 1: In the middle of a page, no duplicates, just dec the index. * Case 2: In the middle of a duplicate set, back up one. * Case 3: At the beginning of a duplicate set, get out of set and * back up to next key. * Case 4: At the beginning of a page; go to previous page. * Case 5: At the beginning of a bucket; go to prev bucket. */ F_CLR(hcp, H_OK | H_NOMORE | H_DELETED); if ((ret = __ham_get_cpage(dbc, mode)) != 0) return (ret); /* * First handle the duplicates. Either you'll get the key here * or you'll exit the duplicate set and drop into the code below * to handle backing up through keys. */ if (!F_ISSET(hcp, H_NEXT_NODUP) && F_ISSET(hcp, H_ISDUP)) { if (HPAGE_TYPE(hcp->page, H_DATAINDEX(hcp->indx)) == H_OFFDUP) { memcpy(pgnop, HOFFDUP_PGNO(H_PAIRDATA(hcp->page, hcp->indx)), sizeof(db_pgno_t)); F_SET(hcp, H_OK); return (0); } /* Duplicates are on-page. */ if (hcp->dup_off != 0) { memcpy(&hcp->dup_len, HKEYDATA_DATA( H_PAIRDATA(hcp->page, hcp->indx)) + hcp->dup_off - sizeof(db_indx_t), sizeof(db_indx_t)); hcp->dup_off -= DUP_SIZE(hcp->dup_len); return (__ham_item(dbc, mode, pgnop)); } } /* * If we get here, we are not in a duplicate set, and just need * to back up the cursor. There are still three cases: * midpage, beginning of page, beginning of bucket. */ if (F_ISSET(hcp, H_DUPONLY)) { F_CLR(hcp, H_OK); F_SET(hcp, H_NOMORE); return (0); } else /* * We are no longer in a dup set; flag this so the dup code * will reinitialize should we stumble upon another one. */ F_CLR(hcp, H_ISDUP); if (hcp->indx == 0) { /* Beginning of page. */ hcp->pgno = PREV_PGNO(hcp->page); if (hcp->pgno == PGNO_INVALID) { /* Beginning of bucket. */ F_SET(hcp, H_NOMORE); return (DB_NOTFOUND); } else if ((ret = __ham_next_cpage(dbc, hcp->pgno, 0)) != 0) return (ret); else hcp->indx = NUM_ENT(hcp->page); } /* * Either we've got the cursor set up to be decremented, or we * have to find the end of a bucket. */ if (hcp->indx == NDX_INVALID) { DB_ASSERT(hcp->page != NULL); hcp->indx = NUM_ENT(hcp->page); for (next_pgno = NEXT_PGNO(hcp->page); next_pgno != PGNO_INVALID; next_pgno = NEXT_PGNO(hcp->page)) { if ((ret = __ham_next_cpage(dbc, next_pgno, 0)) != 0) return (ret); hcp->indx = NUM_ENT(hcp->page); } if (hcp->indx == 0) { /* Bucket was empty. */ F_SET(hcp, H_NOMORE); return (DB_NOTFOUND); } } hcp->indx -= 2; return (__ham_item(dbc, mode, pgnop)); } /* * Sets the cursor to the next key/data pair on a page. * * PUBLIC: int __ham_item_next __P((DBC *, db_lockmode_t, db_pgno_t *)); */ int __ham_item_next(dbc, mode, pgnop) DBC *dbc; db_lockmode_t mode; db_pgno_t *pgnop; { HASH_CURSOR *hcp; int ret; hcp = (HASH_CURSOR *)dbc->internal; if ((ret = __ham_get_cpage(dbc, mode)) != 0) return (ret); /* * Deleted on-page duplicates are a weird case. If we delete the last * one, then our cursor is at the very end of a duplicate set and * we actually need to go on to the next key. */ if (F_ISSET(hcp, H_DELETED)) { if (hcp->indx != NDX_INVALID && F_ISSET(hcp, H_ISDUP) && HPAGE_TYPE(hcp->page, H_DATAINDEX(hcp->indx)) == H_DUPLICATE && hcp->dup_tlen == hcp->dup_off) { if (F_ISSET(hcp, H_DUPONLY)) { F_CLR(hcp, H_OK); F_SET(hcp, H_NOMORE); return (0); } else { F_CLR(hcp, H_ISDUP); hcp->indx += 2; } } else if (!F_ISSET(hcp, H_ISDUP) && F_ISSET(hcp, H_DUPONLY)) { F_CLR(hcp, H_OK); F_SET(hcp, H_NOMORE); return (0); } else if (F_ISSET(hcp, H_ISDUP) && F_ISSET(hcp, H_NEXT_NODUP)) { F_CLR(hcp, H_ISDUP); hcp->indx += 2; } F_CLR(hcp, H_DELETED); } else if (hcp->indx == NDX_INVALID) { hcp->indx = 0; F_CLR(hcp, H_ISDUP); } else if (F_ISSET(hcp, H_NEXT_NODUP)) { hcp->indx += 2; F_CLR(hcp, H_ISDUP); } else if (F_ISSET(hcp, H_ISDUP) && hcp->dup_tlen != 0) { if (hcp->dup_off + DUP_SIZE(hcp->dup_len) >= hcp->dup_tlen && F_ISSET(hcp, H_DUPONLY)) { F_CLR(hcp, H_OK); F_SET(hcp, H_NOMORE); return (0); } hcp->dup_off += DUP_SIZE(hcp->dup_len); if (hcp->dup_off >= hcp->dup_tlen) { F_CLR(hcp, H_ISDUP); hcp->indx += 2; } } else if (F_ISSET(hcp, H_DUPONLY)) { F_CLR(hcp, H_OK); F_SET(hcp, H_NOMORE); return (0); } else { hcp->indx += 2; F_CLR(hcp, H_ISDUP); } return (__ham_item(dbc, mode, pgnop)); } /* * PUBLIC: void __ham_putitem __P((PAGE *p, const DBT *, int)); * * This is a little bit sleazy in that we're overloading the meaning * of the H_OFFPAGE type here. When we recover deletes, we have the * entire entry instead of having only the DBT, so we'll pass type * H_OFFPAGE to mean, "copy the whole entry" as opposed to constructing * an H_KEYDATA around it. */ void __ham_putitem(p, dbt, type) PAGE *p; const DBT *dbt; int type; { u_int16_t n, off; n = NUM_ENT(p); /* Put the item element on the page. */ if (type == H_OFFPAGE) { off = HOFFSET(p) - dbt->size; HOFFSET(p) = p->inp[n] = off; memcpy(P_ENTRY(p, n), dbt->data, dbt->size); } else { off = HOFFSET(p) - HKEYDATA_SIZE(dbt->size); HOFFSET(p) = p->inp[n] = off; PUT_HKEYDATA(P_ENTRY(p, n), dbt->data, dbt->size, type); } /* Adjust page info. */ NUM_ENT(p) += 1; } /* * PUBLIC: void __ham_reputpair * PUBLIC: __P((PAGE *p, u_int32_t, u_int32_t, const DBT *, const DBT *)); * * This is a special case to restore a key/data pair to its original * location during recovery. We are guaranteed that the pair fits * on the page and is not the last pair on the page (because if it's * the last pair, the normal insert works). */ void __ham_reputpair(p, psize, ndx, key, data) PAGE *p; u_int32_t psize, ndx; const DBT *key, *data; { db_indx_t i, movebytes, newbytes; u_int8_t *from; /* First shuffle the existing items up on the page. */ movebytes = (ndx == 0 ? psize : p->inp[H_DATAINDEX(ndx - 2)]) - HOFFSET(p); newbytes = key->size + data->size; from = (u_int8_t *)p + HOFFSET(p); memmove(from - newbytes, from, movebytes); /* * Adjust the indices and move them up 2 spaces. Note that we * have to check the exit condition inside the loop just in case * we are dealing with index 0 (db_indx_t's are unsigned). */ for (i = NUM_ENT(p) - 1; ; i-- ) { p->inp[i + 2] = p->inp[i] - newbytes; if (i == H_KEYINDEX(ndx)) break; } /* Put the key and data on the page. */ p->inp[H_KEYINDEX(ndx)] = (ndx == 0 ? psize : p->inp[H_DATAINDEX(ndx - 2)]) - key->size; p->inp[H_DATAINDEX(ndx)] = p->inp[H_KEYINDEX(ndx)] - data->size; memcpy(P_ENTRY(p, H_KEYINDEX(ndx)), key->data, key->size); memcpy(P_ENTRY(p, H_DATAINDEX(ndx)), data->data, data->size); /* Adjust page info. */ HOFFSET(p) -= newbytes; NUM_ENT(p) += 2; } /* * PUBLIC: int __ham_del_pair __P((DBC *, int)); */ int __ham_del_pair(dbc, reclaim_page) DBC *dbc; int reclaim_page; { DB *dbp; HASH_CURSOR *hcp; DBT data_dbt, key_dbt; DB_ENV *dbenv; DB_LSN new_lsn, *n_lsn, tmp_lsn; PAGE *n_pagep, *nn_pagep, *p, *p_pagep; db_indx_t ndx; db_pgno_t chg_pgno, pgno, tmp_pgno; int ret, t_ret; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; dbenv = dbp->dbenv; ndx = hcp->indx; n_pagep = p_pagep = nn_pagep = NULL; if (hcp->page == NULL && (ret = memp_fget(dbp->mpf, &hcp->pgno, DB_MPOOL_CREATE, &hcp->page)) != 0) return (ret); p = hcp->page; /* * We optimize for the normal case which is when neither the key nor * the data are large. In this case, we write a single log record * and do the delete. If either is large, we'll call __big_delete * to remove the big item and then update the page to remove the * entry referring to the big item. */ ret = 0; if (HPAGE_PTYPE(H_PAIRKEY(p, ndx)) == H_OFFPAGE) { memcpy(&pgno, HOFFPAGE_PGNO(P_ENTRY(p, H_KEYINDEX(ndx))), sizeof(db_pgno_t)); ret = __db_doff(dbc, pgno); } if (ret == 0) switch (HPAGE_PTYPE(H_PAIRDATA(p, ndx))) { case H_OFFPAGE: memcpy(&pgno, HOFFPAGE_PGNO(P_ENTRY(p, H_DATAINDEX(ndx))), sizeof(db_pgno_t)); ret = __db_doff(dbc, pgno); break; case H_OFFDUP: case H_DUPLICATE: /* * If we delete a pair that is/was a duplicate, then * we had better clear the flag so that we update the * cursor appropriately. */ F_CLR(hcp, H_ISDUP); break; } if (ret) return (ret); /* Now log the delete off this page. */ if (DB_LOGGING(dbc)) { key_dbt.data = P_ENTRY(p, H_KEYINDEX(ndx)); key_dbt.size = LEN_HITEM(p, dbp->pgsize, H_KEYINDEX(ndx)); data_dbt.data = P_ENTRY(p, H_DATAINDEX(ndx)); data_dbt.size = LEN_HITEM(p, dbp->pgsize, H_DATAINDEX(ndx)); if ((ret = __ham_insdel_log(dbenv, dbc->txn, &new_lsn, 0, DELPAIR, dbp->log_fileid, PGNO(p), (u_int32_t)ndx, &LSN(p), &key_dbt, &data_dbt)) != 0) return (ret); /* Move lsn onto page. */ LSN(p) = new_lsn; } /* Do the delete. */ __ham_dpair(dbp, p, ndx); /* * Mark item deleted so that we don't try to return it, and * so that we update the cursor correctly on the next call * to next. */ F_SET(hcp, H_DELETED); F_CLR(hcp, H_OK); /* * Update cursors that are on the page where the delete happend. */ if ((ret = __ham_c_update(dbc, 0, 0, 0)) != 0) return (ret); /* * If we are locking, we will not maintain this, because it is * a hot spot. * * XXX * Perhaps we can retain incremental numbers and apply them later. */ if (!STD_LOCKING(dbc)) --hcp->hdr->nelem; /* * If we need to reclaim the page, then check if the page is empty. * There are two cases. If it's empty and it's not the first page * in the bucket (i.e., the bucket page) then we can simply remove * it. If it is the first chain in the bucket, then we need to copy * the second page into it and remove the second page. * If its the only page in the bucket we leave it alone. */ if (!reclaim_page || NUM_ENT(p) != 0 || (PREV_PGNO(p) == PGNO_INVALID && NEXT_PGNO(p) == PGNO_INVALID)) return (memp_fset(dbp->mpf, p, DB_MPOOL_DIRTY)); if (PREV_PGNO(p) == PGNO_INVALID) { /* * First page in chain is empty and we know that there * are more pages in the chain. */ if ((ret = memp_fget(dbp->mpf, &NEXT_PGNO(p), 0, &n_pagep)) != 0) return (ret); if (NEXT_PGNO(n_pagep) != PGNO_INVALID && (ret = memp_fget(dbp->mpf, &NEXT_PGNO(n_pagep), 0, &nn_pagep)) != 0) goto err; if (DB_LOGGING(dbc)) { key_dbt.data = n_pagep; key_dbt.size = dbp->pgsize; if ((ret = __ham_copypage_log(dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, PGNO(p), &LSN(p), PGNO(n_pagep), &LSN(n_pagep), NEXT_PGNO(n_pagep), nn_pagep == NULL ? NULL : &LSN(nn_pagep), &key_dbt)) != 0) goto err; /* Move lsn onto page. */ LSN(p) = new_lsn; /* Structure assignment. */ LSN(n_pagep) = new_lsn; if (NEXT_PGNO(n_pagep) != PGNO_INVALID) LSN(nn_pagep) = new_lsn; } if (nn_pagep != NULL) { PREV_PGNO(nn_pagep) = PGNO(p); if ((ret = memp_fput(dbp->mpf, nn_pagep, DB_MPOOL_DIRTY)) != 0) { nn_pagep = NULL; goto err; } } tmp_pgno = PGNO(p); tmp_lsn = LSN(p); memcpy(p, n_pagep, dbp->pgsize); PGNO(p) = tmp_pgno; LSN(p) = tmp_lsn; PREV_PGNO(p) = PGNO_INVALID; /* * Update cursors to reflect the fact that records * on the second page have moved to the first page. */ if ((ret = __ham_c_chgpg(dbc, PGNO(n_pagep), NDX_INVALID, PGNO(p), NDX_INVALID)) != 0) return (ret); /* * Update the cursor to reflect its new position. */ hcp->indx = 0; hcp->pgno = PGNO(p); if ((ret = memp_fset(dbp->mpf, p, DB_MPOOL_DIRTY)) != 0 || (ret = __db_free(dbc, n_pagep)) != 0) return (ret); } else { if ((ret = memp_fget(dbp->mpf, &PREV_PGNO(p), 0, &p_pagep)) != 0) goto err; if (NEXT_PGNO(p) != PGNO_INVALID) { if ((ret = memp_fget(dbp->mpf, &NEXT_PGNO(p), 0, &n_pagep)) != 0) goto err; n_lsn = &LSN(n_pagep); } else { n_pagep = NULL; n_lsn = NULL; } NEXT_PGNO(p_pagep) = NEXT_PGNO(p); if (n_pagep != NULL) PREV_PGNO(n_pagep) = PGNO(p_pagep); if (DB_LOGGING(dbc)) { if ((ret = __ham_newpage_log(dbenv, dbc->txn, &new_lsn, 0, DELOVFL, dbp->log_fileid, PREV_PGNO(p), &LSN(p_pagep), PGNO(p), &LSN(p), NEXT_PGNO(p), n_lsn)) != 0) goto err; /* Move lsn onto page. */ LSN(p_pagep) = new_lsn; /* Structure assignment. */ if (n_pagep) LSN(n_pagep) = new_lsn; LSN(p) = new_lsn; } if (NEXT_PGNO(p) == PGNO_INVALID) { /* * There is no next page; put the cursor on the * previous page as if we'd deleted the last item * on that page; index greater than number of * valid entries and H_DELETED set. */ hcp->pgno = PGNO(p_pagep); hcp->indx = NUM_ENT(p_pagep); F_SET(hcp, H_DELETED); } else { hcp->pgno = NEXT_PGNO(p); hcp->indx = 0; } /* * Since we are about to delete the cursor page and we have * just moved the cursor, we need to make sure that the * old page pointer isn't left hanging around in the cursor. */ hcp->page = NULL; chg_pgno = PGNO(p); ret = __db_free(dbc, p); if ((t_ret = memp_fput(dbp->mpf, p_pagep, DB_MPOOL_DIRTY)) != 0 && ret == 0) ret = t_ret; if (n_pagep != NULL && (t_ret = memp_fput(dbp->mpf, n_pagep, DB_MPOOL_DIRTY)) != 0 && ret == 0) ret = t_ret; if (ret != 0) return (ret); ret = __ham_c_chgpg(dbc, chg_pgno, 0, hcp->pgno, hcp->indx); } return (ret); err: /* Clean up any pages. */ if (n_pagep != NULL) (void)memp_fput(dbp->mpf, n_pagep, 0); if (nn_pagep != NULL) (void)memp_fput(dbp->mpf, nn_pagep, 0); if (p_pagep != NULL) (void)memp_fput(dbp->mpf, p_pagep, 0); return (ret); } /* * __ham_replpair -- * Given the key data indicated by the cursor, replace part/all of it * according to the fields in the dbt. * * PUBLIC: int __ham_replpair __P((DBC *, DBT *, u_int32_t)); */ int __ham_replpair(dbc, dbt, make_dup) DBC *dbc; DBT *dbt; u_int32_t make_dup; { DB *dbp; HASH_CURSOR *hcp; DBT old_dbt, tdata, tmp; DB_LSN new_lsn; int32_t change; /* XXX: Possible overflow. */ u_int32_t dup, len, memsize; int is_big, ret, type; u_int8_t *beg, *dest, *end, *hk, *src; void *memp; /* * Big item replacements are handled in generic code. * Items that fit on the current page fall into 4 classes. * 1. On-page element, same size * 2. On-page element, new is bigger (fits) * 3. On-page element, new is bigger (does not fit) * 4. On-page element, old is bigger * Numbers 1, 2, and 4 are essentially the same (and should * be the common case). We handle case 3 as a delete and * add. */ dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; /* * We need to compute the number of bytes that we are adding or * removing from the entry. Normally, we can simply substract * the number of bytes we are replacing (dbt->dlen) from the * number of bytes we are inserting (dbt->size). However, if * we are doing a partial put off the end of a record, then this * formula doesn't work, because we are essentially adding * new bytes. */ change = dbt->size - dbt->dlen; hk = H_PAIRDATA(hcp->page, hcp->indx); is_big = HPAGE_PTYPE(hk) == H_OFFPAGE; if (is_big) memcpy(&len, HOFFPAGE_TLEN(hk), sizeof(u_int32_t)); else len = LEN_HKEYDATA(hcp->page, dbp->pgsize, H_DATAINDEX(hcp->indx)); if (dbt->doff + dbt->dlen > len) change += dbt->doff + dbt->dlen - len; if (change > (int32_t)P_FREESPACE(hcp->page) || is_big) { /* * Case 3 -- two subcases. * A. This is not really a partial operation, but an overwrite. * Simple del and add works. * B. This is a partial and we need to construct the data that * we are really inserting (yuck). * In both cases, we need to grab the key off the page (in * some cases we could do this outside of this routine; for * cleanliness we do it here. If you happen to be on a big * key, this could be a performance hit). */ memset(&tmp, 0, sizeof(tmp)); if ((ret = __db_ret(dbp, hcp->page, H_KEYINDEX(hcp->indx), &tmp, &dbc->rkey.data, &dbc->rkey.ulen)) != 0) return (ret); /* Preserve duplicate info. */ dup = F_ISSET(hcp, H_ISDUP); if (dbt->doff == 0 && dbt->dlen == len) { ret = __ham_del_pair(dbc, 0); if (ret == 0) ret = __ham_add_el(dbc, &tmp, dbt, dup ? H_DUPLICATE : H_KEYDATA); } else { /* Case B */ type = HPAGE_PTYPE(hk) != H_OFFPAGE ? HPAGE_PTYPE(hk) : H_KEYDATA; memset(&tdata, 0, sizeof(tdata)); memp = NULL; memsize = 0; if ((ret = __db_ret(dbp, hcp->page, H_DATAINDEX(hcp->indx), &tdata, &memp, &memsize)) != 0) goto err; /* Now we can delete the item. */ if ((ret = __ham_del_pair(dbc, 0)) != 0) { __os_free(memp, memsize); goto err; } /* Now shift old data around to make room for new. */ if (change > 0) { if ((ret = __os_realloc(dbp->dbenv, tdata.size + change, NULL, &tdata.data)) != 0) return (ret); memp = tdata.data; memsize = tdata.size + change; memset((u_int8_t *)tdata.data + tdata.size, 0, change); } end = (u_int8_t *)tdata.data + tdata.size; src = (u_int8_t *)tdata.data + dbt->doff + dbt->dlen; if (src < end && tdata.size > dbt->doff + dbt->dlen) { len = tdata.size - dbt->doff - dbt->dlen; dest = src + change; memmove(dest, src, len); } memcpy((u_int8_t *)tdata.data + dbt->doff, dbt->data, dbt->size); tdata.size += change; /* Now add the pair. */ ret = __ham_add_el(dbc, &tmp, &tdata, type); __os_free(memp, memsize); } F_SET(hcp, dup); err: return (ret); } /* * Set up pointer into existing data. Do it before the log * message so we can use it inside of the log setup. */ beg = HKEYDATA_DATA(H_PAIRDATA(hcp->page, hcp->indx)); beg += dbt->doff; /* * If we are going to have to move bytes at all, figure out * all the parameters here. Then log the call before moving * anything around. */ if (DB_LOGGING(dbc)) { old_dbt.data = beg; old_dbt.size = dbt->dlen; if ((ret = __ham_replace_log(dbp->dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, PGNO(hcp->page), (u_int32_t)H_DATAINDEX(hcp->indx), &LSN(hcp->page), (u_int32_t)dbt->doff, &old_dbt, dbt, make_dup)) != 0) return (ret); LSN(hcp->page) = new_lsn; /* Structure assignment. */ } __ham_onpage_replace(hcp->page, dbp->pgsize, (u_int32_t)H_DATAINDEX(hcp->indx), (int32_t)dbt->doff, change, dbt); return (0); } /* * Replace data on a page with new data, possibly growing or shrinking what's * there. This is called on two different occasions. On one (from replpair) * we are interested in changing only the data. On the other (from recovery) * we are replacing the entire data (header and all) with a new element. In * the latter case, the off argument is negative. * pagep: the page that we're changing * ndx: page index of the element that is growing/shrinking. * off: Offset at which we are beginning the replacement. * change: the number of bytes (+ or -) that the element is growing/shrinking. * dbt: the new data that gets written at beg. * PUBLIC: void __ham_onpage_replace __P((PAGE *, size_t, u_int32_t, int32_t, * PUBLIC: int32_t, DBT *)); */ void __ham_onpage_replace(pagep, pgsize, ndx, off, change, dbt) PAGE *pagep; size_t pgsize; u_int32_t ndx; int32_t off; int32_t change; DBT *dbt; { db_indx_t i; int32_t len; u_int8_t *src, *dest; int zero_me; if (change != 0) { zero_me = 0; src = (u_int8_t *)(pagep) + HOFFSET(pagep); if (off < 0) len = pagep->inp[ndx] - HOFFSET(pagep); else if ((u_int32_t)off >= LEN_HKEYDATA(pagep, pgsize, ndx)) { len = HKEYDATA_DATA(P_ENTRY(pagep, ndx)) + LEN_HKEYDATA(pagep, pgsize, ndx) - src; zero_me = 1; } else len = (HKEYDATA_DATA(P_ENTRY(pagep, ndx)) + off) - src; dest = src - change; memmove(dest, src, len); if (zero_me) memset(dest + len, 0, change); /* Now update the indices. */ for (i = ndx; i < NUM_ENT(pagep); i++) pagep->inp[i] -= change; HOFFSET(pagep) -= change; } if (off >= 0) memcpy(HKEYDATA_DATA(P_ENTRY(pagep, ndx)) + off, dbt->data, dbt->size); else memcpy(P_ENTRY(pagep, ndx), dbt->data, dbt->size); } /* * PUBLIC: int __ham_split_page __P((DBC *, u_int32_t, u_int32_t)); */ int __ham_split_page(dbc, obucket, nbucket) DBC *dbc; u_int32_t obucket, nbucket; { DB *dbp; DBC **carray; HASH_CURSOR *hcp, *cp; DBT key, page_dbt; DB_ENV *dbenv; DB_LSN new_lsn; PAGE **pp, *old_pagep, *temp_pagep, *new_pagep; db_indx_t n; db_pgno_t bucket_pgno, npgno, next_pgno; u_int32_t big_len, len; int found, i, ret, t_ret; void *big_buf; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; dbenv = dbp->dbenv; temp_pagep = old_pagep = new_pagep = NULL; if ((ret = __ham_get_clist(dbp, obucket, NDX_INVALID, &carray)) != 0) return (ret); bucket_pgno = BUCKET_TO_PAGE(hcp, obucket); if ((ret = memp_fget(dbp->mpf, &bucket_pgno, DB_MPOOL_CREATE, &old_pagep)) != 0) goto err; /* Properly initialize the new bucket page. */ npgno = BUCKET_TO_PAGE(hcp, nbucket); if ((ret = memp_fget(dbp->mpf, &npgno, DB_MPOOL_CREATE, &new_pagep)) != 0) goto err; P_INIT(new_pagep, dbp->pgsize, npgno, PGNO_INVALID, PGNO_INVALID, 0, P_HASH); temp_pagep = hcp->split_buf; memcpy(temp_pagep, old_pagep, dbp->pgsize); if (DB_LOGGING(dbc)) { page_dbt.size = dbp->pgsize; page_dbt.data = old_pagep; if ((ret = __ham_splitdata_log(dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, SPLITOLD, PGNO(old_pagep), &page_dbt, &LSN(old_pagep))) != 0) goto err; } P_INIT(old_pagep, dbp->pgsize, PGNO(old_pagep), PGNO_INVALID, PGNO_INVALID, 0, P_HASH); if (DB_LOGGING(dbc)) LSN(old_pagep) = new_lsn; /* Structure assignment. */ big_len = 0; big_buf = NULL; key.flags = 0; while (temp_pagep != NULL) { for (n = 0; n < (db_indx_t)NUM_ENT(temp_pagep); n += 2) { if ((ret = __db_ret(dbp, temp_pagep, H_KEYINDEX(n), &key, &big_buf, &big_len)) != 0) goto err; if (__ham_call_hash(dbc, key.data, key.size) == obucket) pp = &old_pagep; else pp = &new_pagep; /* * Figure out how many bytes we need on the new * page to store the key/data pair. */ len = LEN_HITEM(temp_pagep, dbp->pgsize, H_DATAINDEX(n)) + LEN_HITEM(temp_pagep, dbp->pgsize, H_KEYINDEX(n)) + 2 * sizeof(db_indx_t); if (P_FREESPACE(*pp) < len) { if (DB_LOGGING(dbc)) { page_dbt.size = dbp->pgsize; page_dbt.data = *pp; if ((ret = __ham_splitdata_log( dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, SPLITNEW, PGNO(*pp), &page_dbt, &LSN(*pp))) != 0) goto err; LSN(*pp) = new_lsn; } if ((ret = __ham_add_ovflpage(dbc, *pp, 1, pp)) != 0) goto err; } /* Check if we need to update a cursor. */ if (carray != NULL) { found = 0; for (i = 0; carray[i] != NULL; i++) { cp = (HASH_CURSOR *)carray[i]->internal; if (cp->pgno == PGNO(temp_pagep) && cp->indx == n) { cp->pgno = PGNO(*pp); cp->indx = NUM_ENT(*pp); found = 1; } } if (found && DB_LOGGING(dbc) && IS_SUBTRANSACTION(dbc->txn)) { if ((ret = __ham_chgpg_log(dbp->dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, DB_HAM_SPLIT, PGNO(temp_pagep), PGNO(*pp), n, NUM_ENT(*pp))) != 0) goto err; } } __ham_copy_item(dbp->pgsize, temp_pagep, H_KEYINDEX(n), *pp); __ham_copy_item(dbp->pgsize, temp_pagep, H_DATAINDEX(n), *pp); } next_pgno = NEXT_PGNO(temp_pagep); /* Clear temp_page; if it's a link overflow page, free it. */ if (PGNO(temp_pagep) != bucket_pgno && (ret = __db_free(dbc, temp_pagep)) != 0) { temp_pagep = NULL; goto err; } if (next_pgno == PGNO_INVALID) temp_pagep = NULL; else if ((ret = memp_fget(dbp->mpf, &next_pgno, DB_MPOOL_CREATE, &temp_pagep)) != 0) goto err; if (temp_pagep != NULL && DB_LOGGING(dbc)) { page_dbt.size = dbp->pgsize; page_dbt.data = temp_pagep; if ((ret = __ham_splitdata_log(dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, SPLITOLD, PGNO(temp_pagep), &page_dbt, &LSN(temp_pagep))) != 0) goto err; LSN(temp_pagep) = new_lsn; } } if (big_buf != NULL) __os_free(big_buf, big_len); /* * If the original bucket spanned multiple pages, then we've got * a pointer to a page that used to be on the bucket chain. It * should be deleted. */ if (temp_pagep != NULL && PGNO(temp_pagep) != bucket_pgno && (ret = __db_free(dbc, temp_pagep)) != 0) { temp_pagep = NULL; goto err; } /* * Write new buckets out. */ if (DB_LOGGING(dbc)) { page_dbt.size = dbp->pgsize; page_dbt.data = old_pagep; if ((ret = __ham_splitdata_log(dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, SPLITNEW, PGNO(old_pagep), &page_dbt, &LSN(old_pagep))) != 0) goto err; LSN(old_pagep) = new_lsn; page_dbt.data = new_pagep; if ((ret = __ham_splitdata_log(dbenv, dbc->txn, &new_lsn, 0, dbp->log_fileid, SPLITNEW, PGNO(new_pagep), &page_dbt, &LSN(new_pagep))) != 0) goto err; LSN(new_pagep) = new_lsn; } ret = memp_fput(dbp->mpf, old_pagep, DB_MPOOL_DIRTY); if ((t_ret = memp_fput(dbp->mpf, new_pagep, DB_MPOOL_DIRTY)) != 0 && ret == 0) ret = t_ret; if (0) { err: if (old_pagep != NULL) (void)memp_fput(dbp->mpf, old_pagep, DB_MPOOL_DIRTY); if (new_pagep != NULL) (void)memp_fput(dbp->mpf, new_pagep, DB_MPOOL_DIRTY); if (temp_pagep != NULL && PGNO(temp_pagep) != bucket_pgno) (void)memp_fput(dbp->mpf, temp_pagep, DB_MPOOL_DIRTY); } if (carray != NULL) /* We never knew its size. */ __os_free(carray, 0); return (ret); } /* * Add the given pair to the page. The page in question may already be * held (i.e. it was already gotten). If it is, then the page is passed * in via the pagep parameter. On return, pagep will contain the page * to which we just added something. This allows us to link overflow * pages and return the new page having correctly put the last page. * * PUBLIC: int __ham_add_el __P((DBC *, const DBT *, const DBT *, int)); */ int __ham_add_el(dbc, key, val, type) DBC *dbc; const DBT *key, *val; int type; { DB *dbp; HASH_CURSOR *hcp; const DBT *pkey, *pdata; DBT key_dbt, data_dbt; DB_LSN new_lsn; HOFFPAGE doff, koff; db_pgno_t next_pgno, pgno; u_int32_t data_size, key_size, pairsize, rectype; int do_expand, is_keybig, is_databig, ret; int key_type, data_type; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; do_expand = 0; pgno = hcp->seek_found_page != PGNO_INVALID ? hcp->seek_found_page : hcp->pgno; if (hcp->page == NULL && (ret = memp_fget(dbp->mpf, &pgno, DB_MPOOL_CREATE, &hcp->page)) != 0) return (ret); key_size = HKEYDATA_PSIZE(key->size); data_size = HKEYDATA_PSIZE(val->size); is_keybig = ISBIG(hcp, key->size); is_databig = ISBIG(hcp, val->size); if (is_keybig) key_size = HOFFPAGE_PSIZE; if (is_databig) data_size = HOFFPAGE_PSIZE; pairsize = key_size + data_size; /* Advance to first page in chain with room for item. */ while (H_NUMPAIRS(hcp->page) && NEXT_PGNO(hcp->page) != PGNO_INVALID) { /* * This may not be the end of the chain, but the pair may fit * anyway. Check if it's a bigpair that fits or a regular * pair that fits. */ if (P_FREESPACE(hcp->page) >= pairsize) break; next_pgno = NEXT_PGNO(hcp->page); if ((ret = __ham_next_cpage(dbc, next_pgno, 0)) != 0) return (ret); } /* * Check if we need to allocate a new page. */ if (P_FREESPACE(hcp->page) < pairsize) { do_expand = 1; if ((ret = __ham_add_ovflpage(dbc, (PAGE *)hcp->page, 1, (PAGE **)&hcp->page)) != 0) return (ret); hcp->pgno = PGNO(hcp->page); } /* * Update cursor. */ hcp->indx = NUM_ENT(hcp->page); F_CLR(hcp, H_DELETED); if (is_keybig) { koff.type = H_OFFPAGE; UMRW_SET(koff.unused[0]); UMRW_SET(koff.unused[1]); UMRW_SET(koff.unused[2]); if ((ret = __db_poff(dbc, key, &koff.pgno)) != 0) return (ret); koff.tlen = key->size; key_dbt.data = &koff; key_dbt.size = sizeof(koff); pkey = &key_dbt; key_type = H_OFFPAGE; } else { pkey = key; key_type = H_KEYDATA; } if (is_databig) { doff.type = H_OFFPAGE; UMRW_SET(doff.unused[0]); UMRW_SET(doff.unused[1]); UMRW_SET(doff.unused[2]); if ((ret = __db_poff(dbc, val, &doff.pgno)) != 0) return (ret); doff.tlen = val->size; data_dbt.data = &doff; data_dbt.size = sizeof(doff); pdata = &data_dbt; data_type = H_OFFPAGE; } else { pdata = val; data_type = type; } if (DB_LOGGING(dbc)) { rectype = PUTPAIR; if (is_databig) rectype |= PAIR_DATAMASK; if (is_keybig) rectype |= PAIR_KEYMASK; if (type == H_DUPLICATE) rectype |= PAIR_DUPMASK; if ((ret = __ham_insdel_log(dbp->dbenv, dbc->txn, &new_lsn, 0, rectype, dbp->log_fileid, PGNO(hcp->page), (u_int32_t)NUM_ENT(hcp->page), &LSN(hcp->page), pkey, pdata)) != 0) return (ret); /* Move lsn onto page. */ LSN(hcp->page) = new_lsn; /* Structure assignment. */ } __ham_putitem(hcp->page, pkey, key_type); __ham_putitem(hcp->page, pdata, data_type); /* * For splits, we are going to update item_info's page number * field, so that we can easily return to the same page the * next time we come in here. For other operations, this shouldn't * matter, since odds are this is the last thing that happens before * we return to the user program. */ hcp->pgno = PGNO(hcp->page); /* * XXX * Maybe keep incremental numbers here. */ if (!STD_LOCKING(dbc)) hcp->hdr->nelem++; if (do_expand || (hcp->hdr->ffactor != 0 && (u_int32_t)H_NUMPAIRS(hcp->page) > hcp->hdr->ffactor)) F_SET(hcp, H_EXPAND); return (0); } /* * Special __putitem call used in splitting -- copies one entry to * another. Works for all types of hash entries (H_OFFPAGE, H_KEYDATA, * H_DUPLICATE, H_OFFDUP). Since we log splits at a high level, we * do not need to do any logging here. * * PUBLIC: void __ham_copy_item __P((size_t, PAGE *, u_int32_t, PAGE *)); */ void __ham_copy_item(pgsize, src_page, src_ndx, dest_page) size_t pgsize; PAGE *src_page; u_int32_t src_ndx; PAGE *dest_page; { u_int32_t len; void *src, *dest; /* * Copy the key and data entries onto this new page. */ src = P_ENTRY(src_page, src_ndx); /* Set up space on dest. */ len = LEN_HITEM(src_page, pgsize, src_ndx); HOFFSET(dest_page) -= len; dest_page->inp[NUM_ENT(dest_page)] = HOFFSET(dest_page); dest = P_ENTRY(dest_page, NUM_ENT(dest_page)); NUM_ENT(dest_page)++; memcpy(dest, src, len); } /* * * Returns: * pointer on success * NULL on error * * PUBLIC: int __ham_add_ovflpage __P((DBC *, PAGE *, int, PAGE **)); */ int __ham_add_ovflpage(dbc, pagep, release, pp) DBC *dbc; PAGE *pagep; int release; PAGE **pp; { DB *dbp; HASH_CURSOR *hcp; DB_LSN new_lsn; PAGE *new_pagep; int ret; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; if ((ret = __db_new(dbc, P_HASH, &new_pagep)) != 0) return (ret); if (DB_LOGGING(dbc)) { if ((ret = __ham_newpage_log(dbp->dbenv, dbc->txn, &new_lsn, 0, PUTOVFL, dbp->log_fileid, PGNO(pagep), &LSN(pagep), PGNO(new_pagep), &LSN(new_pagep), PGNO_INVALID, NULL)) != 0) return (ret); /* Move lsn onto page. */ LSN(pagep) = LSN(new_pagep) = new_lsn; } NEXT_PGNO(pagep) = PGNO(new_pagep); PREV_PGNO(new_pagep) = PGNO(pagep); if (release) ret = memp_fput(dbp->mpf, pagep, DB_MPOOL_DIRTY); *pp = new_pagep; return (ret); } /* * PUBLIC: int __ham_get_cpage __P((DBC *, db_lockmode_t)); */ int __ham_get_cpage(dbc, mode) DBC *dbc; db_lockmode_t mode; { DB *dbp; DB_LOCK tmp_lock; HASH_CURSOR *hcp; int ret; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; ret = 0; /* * There are four cases with respect to buckets and locks. * 1. If there is no lock held, then if we are locking, we should * get the lock. * 2. If there is a lock held, it's for the current bucket, and it's * for the right mode, we don't need to do anything. * 3. If there is a lock held for the current bucket but it's not * strong enough, we need to upgrade. * 4. If there is a lock, but it's for a different bucket, then we need * to release the existing lock and get a new lock. */ tmp_lock.off = LOCK_INVALID; if (STD_LOCKING(dbc)) { if (hcp->lock.off != LOCK_INVALID && hcp->lbucket != hcp->bucket) { /* Case 4 */ if (dbc->txn == NULL && (ret = lock_put(dbp->dbenv, &hcp->lock)) != 0) return (ret); hcp->lock.off = LOCK_INVALID; } if ((hcp->lock.off != LOCK_INVALID && (hcp->lock_mode == DB_LOCK_READ && mode == DB_LOCK_WRITE))) { /* Case 3. */ tmp_lock = hcp->lock; hcp->lock.off = LOCK_INVALID; } /* Acquire the lock. */ if (hcp->lock.off == LOCK_INVALID) /* Cases 1, 3, and 4. */ if ((ret = __ham_lock_bucket(dbc, mode)) != 0) return (ret); if (ret == 0) { hcp->lock_mode = mode; hcp->lbucket = hcp->bucket; if (tmp_lock.off != LOCK_INVALID) /* Case 3: release the original lock. */ ret = lock_put(dbp->dbenv, &tmp_lock); } else if (tmp_lock.off != LOCK_INVALID) hcp->lock = tmp_lock; } if (ret == 0 && hcp->page == NULL) { if (hcp->pgno == PGNO_INVALID) hcp->pgno = BUCKET_TO_PAGE(hcp, hcp->bucket); if ((ret = memp_fget(dbp->mpf, &hcp->pgno, DB_MPOOL_CREATE, &hcp->page)) != 0) return (ret); } return (0); } /* * Get a new page at the cursor, putting the last page if necessary. * If the flag is set to H_ISDUP, then we are talking about the * duplicate page, not the main page. * * PUBLIC: int __ham_next_cpage __P((DBC *, db_pgno_t, int)); */ int __ham_next_cpage(dbc, pgno, dirty) DBC *dbc; db_pgno_t pgno; int dirty; { DB *dbp; HASH_CURSOR *hcp; PAGE *p; int ret; dbp = dbc->dbp; hcp = (HASH_CURSOR *)dbc->internal; if (hcp->page != NULL && (ret = memp_fput(dbp->mpf, hcp->page, dirty ? DB_MPOOL_DIRTY : 0)) != 0) return (ret); if ((ret = memp_fget(dbp->mpf, &pgno, DB_MPOOL_CREATE, &p)) != 0) return (ret); hcp->page = p; hcp->pgno = pgno; hcp->indx = 0; return (0); } /* * __ham_lock_bucket -- * Get the lock on a particular bucket. * * PUBLIC: int __ham_lock_bucket __P((DBC *, db_lockmode_t)); */ int __ham_lock_bucket(dbc, mode) DBC *dbc; db_lockmode_t mode; { HASH_CURSOR *hcp; u_int32_t flags; int gotmeta, ret; hcp = (HASH_CURSOR *)dbc->internal; gotmeta = hcp->hdr == NULL ? 1 : 0; if (gotmeta) if ((ret = __ham_get_meta(dbc)) != 0) return (ret); dbc->lock.pgno = BUCKET_TO_PAGE(hcp, hcp->bucket); if (gotmeta) if ((ret = __ham_release_meta(dbc)) != 0) return (ret); flags = 0; if (DB_NONBLOCK(dbc)) LF_SET(DB_LOCK_NOWAIT); ret = lock_get(dbc->dbp->dbenv, dbc->locker, flags, &dbc->lock_dbt, mode, &hcp->lock); hcp->lock_mode = mode; return (ret); } /* * __ham_dpair -- * Delete a pair on a page, paying no attention to what the pair * represents. The caller is responsible for freeing up duplicates * or offpage entries that might be referenced by this pair. * * PUBLIC: void __ham_dpair __P((DB *, PAGE *, u_int32_t)); */ void __ham_dpair(dbp, p, indx) DB *dbp; PAGE *p; u_int32_t indx; { db_indx_t delta, n; u_int8_t *dest, *src; /* * Compute "delta", the amount we have to shift all of the * offsets. To find the delta, we just need to calculate * the size of the pair of elements we are removing. */ delta = H_PAIRSIZE(p, dbp->pgsize, indx); /* * The hard case: we want to remove something other than * the last item on the page. We need to shift data and * offsets down. */ if ((db_indx_t)indx != NUM_ENT(p) - 2) { /* * Move the data: src is the first occupied byte on * the page. (Length is delta.) */ src = (u_int8_t *)p + HOFFSET(p); /* * Destination is delta bytes beyond src. This might * be an overlapping copy, so we have to use memmove. */ dest = src + delta; memmove(dest, src, p->inp[H_DATAINDEX(indx)] - HOFFSET(p)); } /* Adjust page metadata. */ HOFFSET(p) = HOFFSET(p) + delta; NUM_ENT(p) = NUM_ENT(p) - 2; /* Adjust the offsets. */ for (n = (db_indx_t)indx; n < (db_indx_t)(NUM_ENT(p)); n++) p->inp[n] = p->inp[n + 2] + delta; }