/* * Assume that hashp has been set in wrapper routine. */ static int hash_access(HTAB *hashp, ACTION action, DBT *key, DBT *val) { BUFHEAD *rbufp; BUFHEAD *bufp, *save_bufp; u_int16_t *bp; int n, ndx, off, size; char *kp; u_int16_t pageno; #ifdef HASH_STATISTICS hash_accesses++; #endif off = hashp->BSIZE; size = key->size; kp = (char *)key->data; rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0); if (!rbufp) return (ERROR); save_bufp = rbufp; /* Pin the bucket chain */ rbufp->flags |= BUF_PIN; for (bp = (u_int16_t *)rbufp->page, n = *bp++, ndx = 1; ndx < n;) if (bp[1] >= REAL_KEY) { /* Real key/data pair */ if (size == off - *bp && memcmp(kp, rbufp->page + *bp, size) == 0) goto found; off = bp[1]; #ifdef HASH_STATISTICS hash_collisions++; #endif bp += 2; ndx += 2; } else if (bp[1] == OVFLPAGE) { rbufp = __get_buf(hashp, *bp, rbufp, 0); if (!rbufp) { save_bufp->flags &= ~BUF_PIN; return (ERROR); } /* FOR LOOP INIT */ bp = (u_int16_t *)rbufp->page; n = *bp++; ndx = 1; off = hashp->BSIZE; } else if (bp[1] < REAL_KEY) { if ((ndx = __find_bigpair(hashp, rbufp, ndx, kp, size)) > 0) goto found; if (ndx == -2) { bufp = rbufp; if (!(pageno = __find_last_page(hashp, &bufp))) { ndx = 0; rbufp = bufp; break; /* FOR */ } rbufp = __get_buf(hashp, pageno, bufp, 0); if (!rbufp) { save_bufp->flags &= ~BUF_PIN; return (ERROR); } /* FOR LOOP INIT */ bp = (u_int16_t *)rbufp->page; n = *bp++; ndx = 1; off = hashp->BSIZE; } else { save_bufp->flags &= ~BUF_PIN; return (ERROR); } } /* Not found */ switch (action) { case HASH_PUT: case HASH_PUTNEW: if (__addel(hashp, rbufp, key, val)) { save_bufp->flags &= ~BUF_PIN; return (ERROR); } else { save_bufp->flags &= ~BUF_PIN; return (SUCCESS); } case HASH_GET: case HASH_DELETE: default: save_bufp->flags &= ~BUF_PIN; return (ABNORMAL); } found: switch (action) { case HASH_PUTNEW: save_bufp->flags &= ~BUF_PIN; return (ABNORMAL); case HASH_GET: bp = (u_int16_t *)rbufp->page; if (bp[ndx + 1] < REAL_KEY) { if (__big_return(hashp, rbufp, ndx, val, 0)) return (ERROR); } else { val->data = (u_char *)rbufp->page + (int)bp[ndx + 1]; val->size = bp[ndx] - bp[ndx + 1]; } break; case HASH_PUT: if ((__delpair(hashp, rbufp, ndx)) || (__addel(hashp, rbufp, key, val))) { save_bufp->flags &= ~BUF_PIN; return (ERROR); } break; case HASH_DELETE: if (__delpair(hashp, rbufp, ndx)) return (ERROR); break; default: abort(); } save_bufp->flags &= ~BUF_PIN; return (SUCCESS); }
/* * Assume that hashp has been set in wrapper routine. */ static int hash_access( HTAB *hashp, ACTION action, DBT *key, DBT *val) { register BUFHEAD *rbufp; BUFHEAD *bufp, *save_bufp; register uint16 *bp; register long n, ndx, off; register size_t size; register char *kp; uint16 pageno; uint32 ovfl_loop_count=0; int32 last_overflow_page_no = -1; #ifdef HASH_STATISTICS hash_accesses++; #endif off = hashp->BSIZE; size = key->size; kp = (char *)key->data; rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0); if (!rbufp) return (DATABASE_CORRUPTED_ERROR); save_bufp = rbufp; /* Pin the bucket chain */ rbufp->flags |= BUF_PIN; for (bp = (uint16 *)rbufp->page, n = *bp++, ndx = 1; ndx < n;) { if (bp[1] >= REAL_KEY) { /* Real key/data pair */ if (size == (unsigned long)(off - *bp) && memcmp(kp, rbufp->page + *bp, size) == 0) goto found; off = bp[1]; #ifdef HASH_STATISTICS hash_collisions++; #endif bp += 2; ndx += 2; } else if (bp[1] == OVFLPAGE) { /* database corruption: overflow loop detection */ if(last_overflow_page_no == (int32)*bp) return (DATABASE_CORRUPTED_ERROR); last_overflow_page_no = *bp; rbufp = __get_buf(hashp, *bp, rbufp, 0); if (!rbufp) { save_bufp->flags &= ~BUF_PIN; return (DBM_ERROR); } ovfl_loop_count++; if(ovfl_loop_count > MAX_OVERFLOW_HASH_ACCESS_LOOPS) return (DATABASE_CORRUPTED_ERROR); /* FOR LOOP INIT */ bp = (uint16 *)rbufp->page; n = *bp++; ndx = 1; off = hashp->BSIZE; } else if (bp[1] < REAL_KEY) { if ((ndx = __find_bigpair(hashp, rbufp, ndx, kp, (int)size)) > 0) goto found; if (ndx == -2) { bufp = rbufp; if (!(pageno = __find_last_page(hashp, &bufp))) { ndx = 0; rbufp = bufp; break; /* FOR */ } rbufp = __get_buf(hashp, pageno, bufp, 0); if (!rbufp) { save_bufp->flags &= ~BUF_PIN; return (DBM_ERROR); } /* FOR LOOP INIT */ bp = (uint16 *)rbufp->page; n = *bp++; ndx = 1; off = hashp->BSIZE; } else { save_bufp->flags &= ~BUF_PIN; return (DBM_ERROR); } } } /* Not found */ switch (action) { case HASH_PUT: case HASH_PUTNEW: if (__addel(hashp, rbufp, key, val)) { save_bufp->flags &= ~BUF_PIN; return (DBM_ERROR); } else { save_bufp->flags &= ~BUF_PIN; return (SUCCESS); } case HASH_GET: case HASH_DELETE: default: save_bufp->flags &= ~BUF_PIN; return (ABNORMAL); } found: switch (action) { case HASH_PUTNEW: save_bufp->flags &= ~BUF_PIN; return (ABNORMAL); case HASH_GET: bp = (uint16 *)rbufp->page; if (bp[ndx + 1] < REAL_KEY) { if (__big_return(hashp, rbufp, ndx, val, 0)) return (DBM_ERROR); } else { val->data = (uint8 *)rbufp->page + (int)bp[ndx + 1]; val->size = bp[ndx] - bp[ndx + 1]; } break; case HASH_PUT: if ((__delpair(hashp, rbufp, ndx)) || (__addel(hashp, rbufp, key, val))) { save_bufp->flags &= ~BUF_PIN; return (DBM_ERROR); } break; case HASH_DELETE: if (__delpair(hashp, rbufp, ndx)) return (DBM_ERROR); break; default: abort(); } save_bufp->flags &= ~BUF_PIN; return (SUCCESS); }