150995Sbostic /*- 250995Sbostic * Copyright (c) 1991 The Regents of the University of California. 350995Sbostic * All rights reserved. 450995Sbostic * 550995Sbostic * %sccs.include.redist.c% 650995Sbostic */ 750995Sbostic 850995Sbostic #ifndef lint 9*56760Sbostic static char sccsid[] = "@(#)rec_seq.c 5.5 (Berkeley) 11/13/92"; 1050995Sbostic #endif /* not lint */ 1150995Sbostic 1250995Sbostic #include <sys/types.h> 1355316Sbostic 14*56760Sbostic #include <db.h> 1550995Sbostic #include <errno.h> 1650995Sbostic #include <limits.h> 1750995Sbostic #include <stdio.h> 1855316Sbostic #include <strings.h> 19*56760Sbostic 2051091Sbostic #include "recno.h" 2150995Sbostic 2250995Sbostic /* 2350995Sbostic * __REC_SEQ -- Recno sequential scan interface. 2450995Sbostic * 2550995Sbostic * Parameters: 2650995Sbostic * dbp: pointer to access method 2750995Sbostic * key: key for positioning and return value 2850995Sbostic * data: data return value 2950995Sbostic * flags: R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV. 3050995Sbostic * 3150995Sbostic * Returns: 3250995Sbostic * RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key. 3350995Sbostic */ 3450995Sbostic int 3550995Sbostic __rec_seq(dbp, key, data, flags) 3650995Sbostic const DB *dbp; 3750995Sbostic DBT *key, *data; 3850995Sbostic u_int flags; 3950995Sbostic { 4050995Sbostic BTREE *t; 4150995Sbostic EPG *e; 4250995Sbostic recno_t nrec; 4351091Sbostic int status; 4450995Sbostic 4550995Sbostic t = dbp->internal; 4650995Sbostic switch(flags) { 4750995Sbostic case R_CURSOR: 48*56760Sbostic if ((nrec = *(recno_t *)key->data) == 0) 49*56760Sbostic goto einval; 5050995Sbostic break; 5150995Sbostic case R_NEXT: 5250995Sbostic if (ISSET(t, BTF_SEQINIT)) { 5350995Sbostic nrec = t->bt_rcursor + 1; 5450995Sbostic break; 5550995Sbostic } 5650995Sbostic /* FALLTHROUGH */ 5750995Sbostic case R_FIRST: 5850995Sbostic nrec = 1; 5950995Sbostic break; 6050995Sbostic case R_PREV: 6150995Sbostic if (ISSET(t, BTF_SEQINIT)) { 62*56760Sbostic if ((nrec = t->bt_rcursor - 1) == 0) 63*56760Sbostic return (RET_SPECIAL); 6450995Sbostic break; 6550995Sbostic } 6650995Sbostic /* FALLTHROUGH */ 6750995Sbostic case R_LAST: 68*56760Sbostic if (!ISSET(t, BTF_RINMEM) && 69*56760Sbostic t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 7050995Sbostic return (RET_ERROR); 7150995Sbostic nrec = t->bt_nrecs; 7250995Sbostic break; 7350995Sbostic default: 74*56760Sbostic einval: errno = EINVAL; 7550995Sbostic return (RET_ERROR); 7650995Sbostic } 7750995Sbostic 7854283Sbostic if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) { 79*56760Sbostic if (!ISSET(t, BTF_RINMEM) && 80*56760Sbostic (status = t->bt_irec(t, nrec)) != RET_SUCCESS) 8151091Sbostic return (status); 8254283Sbostic if (t->bt_nrecs == 0 || nrec > t->bt_nrecs) 8351091Sbostic return (RET_SPECIAL); 8451091Sbostic } 8550995Sbostic 8651091Sbostic if ((e = __rec_search(t, nrec - 1, SEARCH)) == NULL) 8750995Sbostic return (RET_ERROR); 8850995Sbostic 89*56760Sbostic SET(t, BTF_SEQINIT); 90*56760Sbostic t->bt_rcursor = nrec; 91*56760Sbostic 92*56760Sbostic status = __rec_ret(t, e, nrec, key, data); 93*56760Sbostic 9450995Sbostic mpool_put(t->bt_mp, e->page, 0); 9550995Sbostic return (status); 9650995Sbostic } 97