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36 * @(#)rec_delete.c 8.7 (Berkeley) 7/14/94
37 * $DragonFly: src/lib/libcr/db/recno/Attic/rec_delete.c,v 1.2 2003/06/17 04:26:42 dillon Exp $
40 #include <sys/types.h>
49 static int rec_rdelete __P((BTREE *, recno_t));
52 * __REC_DELETE -- Delete the item(s) referenced by a key.
55 * dbp: pointer to access method
57 * flags: R_CURSOR if deleting what the cursor references
60 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
63 __rec_delete(dbp, key, flags)
74 /* Toss any page pinned across calls. */
75 if (t->bt_pinned != NULL) {
76 mpool_put(t->bt_mp, t->bt_pinned, 0);
82 if ((nrec = *(recno_t *)key->data) == 0)
84 if (nrec > t->bt_nrecs)
87 status = rec_rdelete(t, nrec);
90 if (!F_ISSET(&t->bt_cursor, CURS_INIT))
94 status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
95 if (status == RET_SUCCESS)
96 --t->bt_cursor.rcursor;
99 einval: errno = EINVAL;
103 if (status == RET_SUCCESS)
104 F_SET(t, B_MODIFIED | R_MODIFIED);
109 * REC_RDELETE -- Delete the data matching the specified key.
113 * nrec: record to delete
116 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
127 /* Find the record; __rec_search pins the page. */
128 if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
131 /* Delete the record. */
133 status = __rec_dleaf(t, h, e->index);
134 if (status != RET_SUCCESS) {
135 mpool_put(t->bt_mp, h, 0);
138 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
139 return (RET_SUCCESS);
143 * __REC_DLEAF -- Delete a single record from a recno leaf page.
147 * index: index on current page to delete
150 * RET_SUCCESS, RET_ERROR.
153 __rec_dleaf(t, h, index)
159 indx_t *ip, cnt, offset;
165 * Delete a record from a recno leaf page. Internal records are never
166 * deleted from internal pages, regardless of the records that caused
167 * them to be added being deleted. Pages made empty by deletion are
168 * not reclaimed. They are, however, made available for reuse.
170 * Pack the remaining entries at the end of the page, shift the indices
171 * down, overwriting the deleted record and its index. If the record
172 * uses overflow pages, make them available for reuse.
174 to = rl = GETRLEAF(h, index);
175 if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
180 * Compress the key/data pairs. Compress and adjust the [BR]LEAF
181 * offsets. Reset the headers.
183 from = (char *)h + h->upper;
184 memmove(from + nbytes, from, (char *)to - from);
187 offset = h->linp[index];
188 for (cnt = &h->linp[index] - (ip = &h->linp[0]); cnt--; ++ip)
191 for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip)
192 ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
193 h->lower -= sizeof(indx_t);
195 return (RET_SUCCESS);