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32 * @(#)rec_delete.c 8.7 (Berkeley) 7/14/94
33 * $FreeBSD: head/lib/libc/db/recno/rec_delete.c 189292 2009-03-03 02:16:12Z delphij $
36 #include <sys/param.h>
45 static int rec_rdelete(BTREE *, recno_t);
48 * __REC_DELETE -- Delete the item(s) referenced by a key.
51 * dbp: pointer to access method
53 * flags: R_CURSOR if deleting what the cursor references
56 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
59 __rec_delete(const DB *dbp, const DBT *key, unsigned int flags)
67 /* Toss any page pinned across calls. */
68 if (t->bt_pinned != NULL) {
69 mpool_put(t->bt_mp, t->bt_pinned, 0);
75 if ((nrec = *(recno_t *)key->data) == 0)
77 if (nrec > t->bt_nrecs)
80 status = rec_rdelete(t, nrec);
83 if (!F_ISSET(&t->bt_cursor, CURS_INIT))
87 status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
88 if (status == RET_SUCCESS)
89 --t->bt_cursor.rcursor;
92 einval: errno = EINVAL;
96 if (status == RET_SUCCESS)
97 F_SET(t, B_MODIFIED | R_MODIFIED);
102 * REC_RDELETE -- Delete the data matching the specified key.
106 * nrec: record to delete
109 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
112 rec_rdelete(BTREE *t, recno_t nrec)
118 /* Find the record; __rec_search pins the page. */
119 if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
122 /* Delete the record. */
124 status = __rec_dleaf(t, h, e->index);
125 if (status != RET_SUCCESS) {
126 mpool_put(t->bt_mp, h, 0);
129 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
130 return (RET_SUCCESS);
134 * __REC_DLEAF -- Delete a single record from a recno leaf page.
138 * idx: index on current page to delete
141 * RET_SUCCESS, RET_ERROR.
144 __rec_dleaf(BTREE *t, PAGE *h, uint32_t idx)
147 indx_t *ip, cnt, offset;
153 * Delete a record from a recno leaf page. Internal records are never
154 * deleted from internal pages, regardless of the records that caused
155 * them to be added being deleted. Pages made empty by deletion are
156 * not reclaimed. They are, however, made available for reuse.
158 * Pack the remaining entries at the end of the page, shift the indices
159 * down, overwriting the deleted record and its index. If the record
160 * uses overflow pages, make them available for reuse.
162 to = rl = GETRLEAF(h, idx);
163 if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
168 * Compress the key/data pairs. Compress and adjust the [BR]LEAF
169 * offsets. Reset the headers.
171 from = (char *)h + h->upper;
172 memmove(from + nbytes, from, (char *)to - from);
175 offset = h->linp[idx];
176 for (cnt = &h->linp[idx] - (ip = &h->linp[0]); cnt--; ++ip)
179 for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip)
180 ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
181 h->lower -= sizeof(indx_t);
183 return (RET_SUCCESS);