/*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Mike Olson. * * %sccs.include.redist.c% */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)bt_put.c 5.15 (Berkeley) 05/16/93"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #include #include "btree.h" static EPG *bt_fast __P((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(dbp, key, data, flags) const DB *dbp; DBT *key; const DBT *data; u_int flags; { BTREE *t; DBT tkey, tdata; EPG *e; PAGE *h; indx_t index, nxtindex; pgno_t pg; size_t nbytes; int dflags, exact, status; char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; t = dbp->internal; switch (flags) { case R_CURSOR: if (!ISSET(t, B_SEQINIT)) goto einval; if (ISSET(t, B_DELCRSR)) goto einval; break; case 0: case R_NOOVERWRITE: break; default: einval: errno = EINVAL; return (RET_ERROR); } if (ISSET(t, B_RDONLY)) { errno = EPERM; return (RET_ERROR); } /* * If the key/data won't fit on a page, store it on indirect pages. * Only store the key on the overflow page if it's too big after the * data is on an overflow page. * * XXX * If the insert fails later on, these 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)); memmove(kb + sizeof(pgno_t), &key->size, sizeof(size_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)); memmove(db + sizeof(pgno_t), &data->size, sizeof(size_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_bcursor.pgno, 0)) == NULL) return (RET_ERROR); index = t->bt_bcursor.index; goto delete; } /* * Find the key to delete, or, the location at which to insert. Bt_fast * and __bt_search 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; index = e->index; /* * Add the specified 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. * * Pages are split as required. */ switch (flags) { case R_NOOVERWRITE: if (!exact) break; /* * One special case is if the cursor references the record and * it's been flagged for deletion. Then, we delete the record, * leaving the cursor there -- this means that the inserted * record will not be seen in a cursor scan. */ if (ISSET(t, B_DELCRSR) && t->bt_bcursor.pgno == h->pgno && t->bt_bcursor.index == index) { CLR(t, B_DELCRSR); goto delete; } mpool_put(t->bt_mp, h, 0); return (RET_SPECIAL); default: if (!exact || !ISSET(t, B_NODUPS)) break; delete: if (__bt_dleaf(t, h, index) == 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, index)) != RET_SUCCESS) return (status); goto success; } if (index < (nxtindex = NEXTINDEX(h))) memmove(h->linp + index + 1, h->linp + index, (nxtindex - index) * sizeof(indx_t)); h->lower += sizeof(indx_t); h->linp[index] = h->upper -= nbytes; dest = (char *)h + h->upper; WR_BLEAF(dest, key, data, dflags); if (t->bt_order == NOT) if (h->nextpg == P_INVALID) { if (index == NEXTINDEX(h) - 1) { t->bt_order = FORWARD; t->bt_last.index = index; t->bt_last.pgno = h->pgno; } } else if (h->prevpg == P_INVALID) { if (index == 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) { t->bt_bcursor.pgno = e->page->pgno; t->bt_bcursor.index = e->index; } 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(t, key, data, exactp) BTREE *t; const DBT *key, *data; int *exactp; { EPG e; PAGE *h; size_t nbytes; int cmp; if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { t->bt_order = NOT; return (NULL); } e.page = h; e.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 (e.page->nextpg != P_INVALID) goto miss; if (e.index != NEXTINDEX(h) - 1) goto miss; if ((cmp = __bt_cmp(t, key, &e)) < 0) goto miss; t->bt_last.index = cmp ? ++e.index : e.index; } else { if (e.page->prevpg != P_INVALID) goto miss; if (e.index != 0) goto miss; if ((cmp = __bt_cmp(t, key, &e)) > 0) goto miss; t->bt_last.index = 0; } *exactp = cmp == 0; #ifdef STATISTICS ++bt_cache_hit; #endif return (&e); miss: #ifdef STATISTICS ++bt_cache_miss; #endif t->bt_order = NOT; mpool_put(t->bt_mp, h, 0); return (NULL); }