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32 * @(#)rec_delete.c 8.7 (Berkeley) 7/14/94
33 * $DragonFly: src/lib/libc/db/recno/rec_delete.c,v 1.4 2005/09/19 09:20:37 asmodai Exp $
36 #include <sys/types.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(dbp, key, flags)
70 /* Toss any page pinned across calls. */
71 if (t->bt_pinned != NULL) {
72 mpool_put(t->bt_mp, t->bt_pinned, 0);
78 if ((nrec = *(recno_t *)key->data) == 0)
80 if (nrec > t->bt_nrecs)
83 status = rec_rdelete(t, nrec);
86 if (!F_ISSET(&t->bt_cursor, CURS_INIT))
90 status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
91 if (status == RET_SUCCESS)
92 --t->bt_cursor.rcursor;
95 einval: errno = EINVAL;
99 if (status == RET_SUCCESS)
100 F_SET(t, B_MODIFIED | R_MODIFIED);
105 * REC_RDELETE -- Delete the data matching the specified key.
109 * nrec: record to delete
112 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
123 /* Find the record; __rec_search pins the page. */
124 if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
127 /* Delete the record. */
129 status = __rec_dleaf(t, h, e->index);
130 if (status != RET_SUCCESS) {
131 mpool_put(t->bt_mp, h, 0);
134 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
135 return (RET_SUCCESS);
139 * __REC_DLEAF -- Delete a single record from a recno leaf page.
143 * index: index on current page to delete
146 * RET_SUCCESS, RET_ERROR.
149 __rec_dleaf(t, h, index)
155 indx_t *ip, cnt, offset;
161 * Delete a record from a recno leaf page. Internal records are never
162 * deleted from internal pages, regardless of the records that caused
163 * them to be added being deleted. Pages made empty by deletion are
164 * not reclaimed. They are, however, made available for reuse.
166 * Pack the remaining entries at the end of the page, shift the indices
167 * down, overwriting the deleted record and its index. If the record
168 * uses overflow pages, make them available for reuse.
170 to = rl = GETRLEAF(h, index);
171 if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
176 * Compress the key/data pairs. Compress and adjust the [BR]LEAF
177 * offsets. Reset the headers.
179 from = (char *)h + h->upper;
180 memmove(from + nbytes, from, (char *)to - from);
183 offset = h->linp[index];
184 for (cnt = &h->linp[index] - (ip = &h->linp[0]); cnt--; ++ip)
187 for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip)
188 ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
189 h->lower -= sizeof(indx_t);
191 return (RET_SUCCESS);