1 /* $Id: isamb.c,v 1.32 2004-06-01 14:51:00 heikki Exp $
2 Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
5 This file is part of the Zebra server.
7 Zebra is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with Zebra; see the file LICENSE.zebra. If not, write to the
19 Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include <yaz/xmalloc.h>
41 #define ISAMB_DATA_OFFSET 3
43 /* maximum size of encoded buffer */
44 #define DST_ITEM_MAX 256
46 #define ISAMB_MAX_LEVEL 10
47 /* approx 2*max page + max size of item */
48 #define DST_BUF_SIZE 16840
50 #define ISAMB_CACHE_ENTRY_SIZE 4096
52 /* CAT_MAX: _must_ be power of 2 */
54 #define CAT_MASK (CAT_MAX-1)
55 /* CAT_NO: <= CAT_MAX */
58 /* ISAMB_PTR_CODEC=1 var, =0 fixed */
59 #define ISAMB_PTR_CODEC 1
61 struct ISAMB_cache_entry {
66 struct ISAMB_cache_entry *next;
72 struct ISAMB_head head;
73 struct ISAMB_cache_entry *cache_entries;
80 struct ISAMB_file *file;
82 int cache; /* 0=no cache, 1=use cache, -1=dummy isam (for testing only) */
83 int log_io; /* log level for bf_read/bf_write calls */
84 int log_freelist; /* log level for freelist handling */
85 int skipped_numbers; /* on a leaf node */
87 int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
88 int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
101 void *decodeClientData;
109 int maxlevel; /* total depth */
112 int skipped_numbers; /* on a leaf node */
113 int returned_numbers;
114 int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
115 int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
116 struct ISAMB_block **block;
120 static void encode_ptr (char **dst, unsigned pos)
122 unsigned char *bp = (unsigned char*) *dst;
126 *bp++ = 128 | (pos & 127);
133 static void encode_ptr (char **dst, unsigned pos)
135 memcpy(*dst, &pos, sizeof(pos));
136 (*dst) += sizeof(pos);
141 static void decode_ptr (char **src1, int *pos)
143 unsigned char **src = (unsigned char **) src1;
148 while (((c = *(*src)++) & 128))
150 d += ((c & 127) << r);
157 static void decode_ptr (char **src, int *pos)
159 memcpy (pos, *src, sizeof(*pos));
160 (*src) += sizeof(*pos);
164 ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method,
167 ISAMB isamb = xmalloc (sizeof(*isamb));
171 isamb->method = (ISAMC_M *) xmalloc (sizeof(*method));
172 memcpy (isamb->method, method, sizeof(*method));
173 isamb->no_cat = CAT_NO;
175 isamb->log_freelist = 0;
176 isamb->cache = cache;
177 isamb->skipped_numbers=0;
178 isamb->returned_numbers=0;
179 for (i=0;i<ISAMB_MAX_LEVEL;i++)
180 isamb->skipped_nodes[i]= isamb->accessed_nodes[i]=0;
183 isamb->file = xmalloc (sizeof(*isamb->file) * isamb->no_cat);
184 for (i = 0; i<isamb->no_cat; i++)
186 char fname[DST_BUF_SIZE];
187 isamb->file[i].cache_entries = 0;
188 isamb->file[i].head_dirty = 0;
189 sprintf (fname, "%s%c", name, i+'A');
191 isamb->file[i].bf = bf_open (bfs, fname, ISAMB_CACHE_ENTRY_SIZE,
194 isamb->file[i].bf = bf_open (bfs, fname, b_size, writeflag);
197 if (!bf_read (isamb->file[i].bf, 0, 0, sizeof(struct ISAMB_head),
198 &isamb->file[i].head))
200 isamb->file[i].head.first_block = ISAMB_CACHE_ENTRY_SIZE/b_size+1;
201 isamb->file[i].head.last_block = isamb->file[i].head.first_block;
202 isamb->file[i].head.block_size = b_size;
203 isamb->file[i].head.block_max = b_size - ISAMB_DATA_OFFSET;
204 isamb->file[i].head.free_list = 0;
206 assert (isamb->file[i].head.block_size >= ISAMB_DATA_OFFSET);
207 isamb->file[i].head_dirty = 0;
208 assert(isamb->file[i].head.block_size == b_size);
214 static void flush_blocks (ISAMB b, int cat)
216 while (b->file[cat].cache_entries)
218 struct ISAMB_cache_entry *ce_this = b->file[cat].cache_entries;
219 b->file[cat].cache_entries = ce_this->next;
223 yaz_log (b->log_io, "bf_write: flush_blocks");
224 bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
226 xfree (ce_this->buf);
231 static int get_block (ISAMB b, ISAMC_P pos, char *userbuf, int wr)
233 int cat = pos&CAT_MASK;
234 int off = ((pos/CAT_MAX) &
235 (ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size - 1))
236 * b->file[cat].head.block_size;
237 int norm = pos / (CAT_MASK*ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size);
239 struct ISAMB_cache_entry **ce, *ce_this = 0, **ce_last = 0;
244 assert (ISAMB_CACHE_ENTRY_SIZE >= b->file[cat].head.block_size);
245 for (ce = &b->file[cat].cache_entries; *ce; ce = &(*ce)->next, no++)
248 if ((*ce)->pos == norm)
251 *ce = (*ce)->next; /* remove from list */
253 ce_this->next = b->file[cat].cache_entries; /* move to front */
254 b->file[cat].cache_entries = ce_this;
258 memcpy (ce_this->buf + off, userbuf,
259 b->file[cat].head.block_size);
263 memcpy (userbuf, ce_this->buf + off,
264 b->file[cat].head.block_size);
271 assert (ce_last && *ce_last);
273 *ce_last = 0; /* remove the last entry from list */
276 yaz_log (b->log_io, "bf_write: get_block");
277 bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
279 xfree (ce_this->buf);
282 ce_this = xmalloc (sizeof(*ce_this));
283 ce_this->next = b->file[cat].cache_entries;
284 b->file[cat].cache_entries = ce_this;
285 ce_this->buf = xmalloc (ISAMB_CACHE_ENTRY_SIZE);
287 yaz_log (b->log_io, "bf_read: get_block");
288 if (!bf_read (b->file[cat].bf, norm, 0, 0, ce_this->buf))
289 memset (ce_this->buf, 0, ISAMB_CACHE_ENTRY_SIZE);
292 memcpy (ce_this->buf + off, userbuf, b->file[cat].head.block_size);
298 memcpy (userbuf, ce_this->buf + off, b->file[cat].head.block_size);
304 void isamb_close (ISAMB isamb)
307 for (i=0;isamb->accessed_nodes[i];i++)
308 logf(LOG_DEBUG,"isamb_close level leaf-%d: %d read, %d skipped",
309 i, isamb->accessed_nodes[i], isamb->skipped_nodes[i]);
310 logf(LOG_DEBUG,"isamb_close returned %d values, skipped %d",
311 isamb->skipped_numbers, isamb->returned_numbers);
312 for (i = 0; i<isamb->no_cat; i++)
314 flush_blocks (isamb, i);
315 if (isamb->file[i].head_dirty)
316 bf_write (isamb->file[i].bf, 0, 0,
317 sizeof(struct ISAMB_head), &isamb->file[i].head);
319 bf_close (isamb->file[i].bf);
322 xfree (isamb->method);
327 struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
329 int cat = pos&CAT_MASK;
330 struct ISAMB_block *p;
333 p = xmalloc (sizeof(*p));
335 p->cat = pos & CAT_MASK;
336 p->buf = xmalloc (b->file[cat].head.block_size);
338 if (!get_block (b, pos, p->buf, 0))
340 yaz_log (b->log_io, "bf_read: open_block");
341 if (!bf_read (b->file[cat].bf, pos/CAT_MAX, 0, 0, p->buf))
343 yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
344 (long) pos, (long) pos/CAT_MAX);
348 p->bytes = p->buf + ISAMB_DATA_OFFSET;
350 p->size = (p->buf[1] + 256 * p->buf[2]) - ISAMB_DATA_OFFSET;
353 yaz_log (LOG_FATAL, "Bad block size %d in pos=%d\n", p->size, pos);
355 assert (p->size >= 0);
359 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
360 yaz_log (LOG_DEBUG, "isamb_open_block: Opened block %d ofs=%d",pos, p->offset);
364 struct ISAMB_block *new_block (ISAMB b, int leaf, int cat)
366 struct ISAMB_block *p;
368 p = xmalloc (sizeof(*p));
369 p->buf = xmalloc (b->file[cat].head.block_size);
371 if (!b->file[cat].head.free_list)
374 block_no = b->file[cat].head.last_block++;
375 p->pos = block_no * CAT_MAX + cat;
379 p->pos = b->file[cat].head.free_list;
380 assert((p->pos & CAT_MASK) == cat);
381 if (!get_block (b, p->pos, p->buf, 0))
383 yaz_log (b->log_io, "bf_read: new_block");
384 if (!bf_read (b->file[cat].bf, p->pos/CAT_MAX, 0, 0, p->buf))
386 yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
387 (long) p->pos/CAT_MAX, (long) p->pos/CAT_MAX);
391 yaz_log (b->log_freelist, "got block %d from freelist %d:%d", p->pos,
392 cat, p->pos/CAT_MAX);
393 memcpy (&b->file[cat].head.free_list, p->buf, sizeof(int));
396 b->file[cat].head_dirty = 1;
397 memset (p->buf, 0, b->file[cat].head.block_size);
398 p->bytes = p->buf + ISAMB_DATA_OFFSET;
404 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
408 struct ISAMB_block *new_leaf (ISAMB b, int cat)
410 return new_block (b, 1, cat);
414 struct ISAMB_block *new_int (ISAMB b, int cat)
416 return new_block (b, 0, cat);
419 static void check_block (ISAMB b, struct ISAMB_block *p)
428 char *startp = p->bytes;
430 char *endp = p->bytes + p->size;
433 decode_ptr (&src, &pos);
434 assert ((pos&CAT_MASK) == p->cat);
438 decode_ptr (&src, &item_len);
439 assert (item_len > 0 && item_len < 30);
441 decode_ptr (&src, &pos);
442 assert ((pos&CAT_MASK) == p->cat);
447 void close_block (ISAMB b, struct ISAMB_block *p)
453 yaz_log (b->log_freelist, "release block %d from freelist %d:%d",
454 p->pos, p->cat, p->pos/CAT_MAX);
455 memcpy (p->buf, &b->file[p->cat].head.free_list, sizeof(int));
456 b->file[p->cat].head.free_list = p->pos;
457 if (!get_block (b, p->pos, p->buf, 1))
459 yaz_log (b->log_io, "bf_write: close_block (deleted)");
460 bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
465 int size = p->size + ISAMB_DATA_OFFSET;
466 assert (p->size >= 0);
468 p->buf[1] = size & 255;
469 p->buf[2] = size >> 8;
471 if (!get_block (b, p->pos, p->buf, 1))
473 yaz_log (b->log_io, "bf_write: close_block");
474 bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
477 (*b->method->code_stop)(ISAMC_DECODE, p->decodeClientData);
482 int insert_sub (ISAMB b, struct ISAMB_block **p,
483 void *new_item, int *mode,
485 struct ISAMB_block **sp,
486 void *sub_item, int *sub_size,
489 int insert_int (ISAMB b, struct ISAMB_block *p, void *lookahead_item,
491 ISAMC_I *stream, struct ISAMB_block **sp,
492 void *split_item, int *split_size, void *last_max_item)
494 char *startp = p->bytes;
496 char *endp = p->bytes + p->size;
498 struct ISAMB_block *sub_p1 = 0, *sub_p2 = 0;
499 char sub_item[DST_ITEM_MAX];
505 assert(p->size >= 0);
506 decode_ptr (&src, &pos);
512 decode_ptr (&src, &item_len);
513 d = (*b->method->compare_item)(src, lookahead_item);
516 sub_p1 = open_block (b, pos);
518 more = insert_sub (b, &sub_p1, lookahead_item, mode,
520 sub_item, &sub_size, src);
525 decode_ptr (&src, &pos);
529 sub_p1 = open_block (b, pos);
531 more = insert_sub (b, &sub_p1, lookahead_item, mode, stream, &sub_p2,
532 sub_item, &sub_size, last_max_item);
536 /* there was a split - must insert pointer in this one */
537 char dst_buf[DST_BUF_SIZE];
540 assert (sub_size < 30 && sub_size > 1);
542 memcpy (dst, startp, src - startp);
546 encode_ptr (&dst, sub_size); /* sub length and item */
547 memcpy (dst, sub_item, sub_size);
550 encode_ptr (&dst, sub_p2->pos); /* pos */
552 if (endp - src) /* remaining data */
554 memcpy (dst, src, endp - src);
557 p->size = dst - dst_buf;
558 assert (p->size >= 0);
559 if (p->size <= b->file[p->cat].head.block_max)
561 memcpy (startp, dst_buf, dst - dst_buf);
570 half = src + b->file[p->cat].head.block_size/2;
571 decode_ptr (&src, &pos);
574 decode_ptr (&src, split_size);
576 decode_ptr (&src, &pos);
578 p_new_size = src - dst_buf;
579 memcpy (p->bytes, dst_buf, p_new_size);
581 decode_ptr (&src, split_size);
582 memcpy (split_item, src, *split_size);
585 *sp = new_int (b, p->cat);
586 (*sp)->size = endp - src;
587 memcpy ((*sp)->bytes, src, (*sp)->size);
589 p->size = p_new_size;
592 close_block (b, sub_p2);
594 close_block (b, sub_p1);
599 int insert_leaf (ISAMB b, struct ISAMB_block **sp1, void *lookahead_item,
600 int *lookahead_mode, ISAMC_I *stream,
601 struct ISAMB_block **sp2,
602 void *sub_item, int *sub_size,
605 struct ISAMB_block *p = *sp1;
606 char *src = 0, *endp = 0;
607 char dst_buf[DST_BUF_SIZE], *dst = dst_buf;
609 void *c1 = (*b->method->code_start)(ISAMC_DECODE);
610 void *c2 = (*b->method->code_start)(ISAMC_ENCODE);
612 int quater = b->file[b->no_cat-1].head.block_max / CAT_MAX;
613 char *cut = dst_buf + quater * 2;
614 char *maxp = dst_buf + b->file[b->no_cat-1].head.block_max;
617 char cut_item_buf[DST_ITEM_MAX];
618 int cut_item_size = 0;
622 char file_item_buf[DST_ITEM_MAX];
623 char *file_item = file_item_buf;
626 endp = p->bytes + p->size;
627 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
632 char *lookahead_next;
636 d = (*b->method->compare_item)(file_item_buf, lookahead_item);
640 dst_item = lookahead_item;
641 if (!*lookahead_mode)
643 yaz_log (LOG_WARN, "isamb: Inconsistent register (1)");
644 assert (*lookahead_mode);
648 dst_item = file_item_buf;
649 if (!*lookahead_mode && d == 0)
653 else if (!half1 && dst > cut)
655 char *dst_item_0 = dst_item;
656 half1 = dst; /* candidate for splitting */
658 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
660 cut_item_size = dst_item - dst_item_0;
661 memcpy (cut_item_buf, dst_item_0, cut_item_size);
666 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
676 lookahead_next = lookahead_item;
677 if (!(*stream->read_item)(stream->clientData,
684 if (lookahead_item && max_item &&
685 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
696 lookahead_next = lookahead_item;
697 if (!(*stream->read_item)(stream->clientData,
698 &lookahead_next, lookahead_mode))
705 file_item = file_item_buf;
706 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
712 file_item = file_item_buf;
713 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
717 maxp = dst_buf + b->file[b->no_cat-1].head.block_max + quater;
718 while (lookahead_item)
720 char *dst_item = lookahead_item;
724 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
729 if (!*lookahead_mode)
731 yaz_log (LOG_WARN, "isamb: Inconsistent register (2)");
734 else if (!half1 && dst > cut)
736 char *dst_item_0 = dst_item;
737 half1 = dst; /* candidate for splitting */
739 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
741 cut_item_size = dst_item - dst_item_0;
742 memcpy (cut_item_buf, dst_item_0, cut_item_size);
747 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
756 dst_item = lookahead_item;
757 if (!(*stream->read_item)(stream->clientData, &dst_item,
764 new_size = dst - dst_buf;
765 if (p && p->cat != b->no_cat-1 &&
766 new_size > b->file[p->cat].head.block_max)
768 /* non-btree block will be removed */
771 /* delete it too!! */
772 p = 0; /* make a new one anyway */
775 { /* must create a new one */
777 for (i = 0; i < b->no_cat; i++)
778 if (new_size <= b->file[i].head.block_max)
784 if (new_size > b->file[p->cat].head.block_max)
787 char *cut_item = cut_item_buf;
793 p->size = half1 - dst_buf;
794 memcpy (p->bytes, dst_buf, half1 - dst_buf);
797 *sp2 = new_leaf (b, p->cat);
799 (*b->method->code_reset)(c2);
801 first_dst = (*sp2)->bytes;
803 (*b->method->code_item)(ISAMC_ENCODE, c2, &first_dst, &cut_item);
805 memcpy (first_dst, half2, dst - half2);
807 (*sp2)->size = (first_dst - (*sp2)->bytes) + (dst - half2);
810 memcpy (sub_item, cut_item_buf, cut_item_size);
811 *sub_size = cut_item_size;
815 memcpy (p->bytes, dst_buf, dst - dst_buf);
818 (*b->method->code_stop)(ISAMC_DECODE, c1);
819 (*b->method->code_stop)(ISAMC_ENCODE, c2);
824 int insert_sub (ISAMB b, struct ISAMB_block **p, void *new_item,
827 struct ISAMB_block **sp,
828 void *sub_item, int *sub_size,
831 if (!*p || (*p)->leaf)
832 return insert_leaf (b, p, new_item, mode, stream, sp, sub_item,
835 return insert_int (b, *p, new_item, mode, stream, sp, sub_item,
839 int isamb_unlink (ISAMB b, ISAMC_P pos)
841 struct ISAMB_block *p1;
845 p1 = open_block(b, pos);
851 char *src = p1->bytes + p1->offset;
853 decode_ptr(&src, &sub_p);
854 isamb_unlink(b, sub_p);
856 while (src != p1->bytes + p1->size)
858 decode_ptr(&src, &item_len);
860 decode_ptr(&src, &sub_p);
861 isamb_unlink(b, sub_p);
868 int isamb_merge (ISAMB b, ISAMC_P pos, ISAMC_I *stream)
870 char item_buf[DST_ITEM_MAX];
882 (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
887 more = (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
890 struct ISAMB_block *p = 0, *sp = 0;
891 char sub_item[DST_ITEM_MAX];
895 p = open_block (b, pos);
896 more = insert_sub (b, &p, item_buf, &i_mode, stream, &sp,
897 sub_item, &sub_size, 0);
899 { /* increase level of tree by one */
900 struct ISAMB_block *p2 = new_int (b, p->cat);
901 char *dst = p2->bytes + p2->size;
903 encode_ptr (&dst, p->pos);
904 assert (sub_size < 20);
905 encode_ptr (&dst, sub_size);
906 memcpy (dst, sub_item, sub_size);
908 encode_ptr (&dst, sp->pos);
910 p2->size = dst - p2->bytes;
911 pos = p2->pos; /* return new super page */
916 pos = p->pos; /* return current one (again) */
922 ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
924 ISAMB_PP pp = xmalloc (sizeof(*pp));
928 pp->block = xmalloc (ISAMB_MAX_LEVEL * sizeof(*pp->block));
935 pp->skipped_numbers=0;
936 pp->returned_numbers=0;
937 for (i=0;i<ISAMB_MAX_LEVEL;i++)
938 pp->skipped_nodes[i] = pp->accessed_nodes[i]=0;
941 struct ISAMB_block *p = open_block (isamb, pos);
942 char *src = p->bytes + p->offset;
943 pp->block[pp->level] = p;
945 pp->total_size += p->size;
951 decode_ptr (&src, &pos);
952 p->offset = src - p->bytes;
954 pp->accessed_nodes[pp->level]++;
956 pp->block[pp->level+1] = 0;
957 pp->maxlevel=pp->level;
963 ISAMB_PP isamb_pp_open (ISAMB isamb, ISAMB_P pos)
965 return isamb_pp_open_x (isamb, pos, 0);
968 void isamb_pp_close_x (ISAMB_PP pp, int *size, int *blocks)
973 logf(LOG_DEBUG,"isamb_pp_close lev=%d returned %d values, skipped %d",
974 pp->maxlevel, pp->skipped_numbers, pp->returned_numbers);
975 for (i=pp->maxlevel;i>=0;i--)
976 if ( pp->skipped_nodes[i] || pp->accessed_nodes[i])
977 logf(LOG_DEBUG,"isamb_pp_close level leaf-%d: %d read, %d skipped", i,
978 pp->accessed_nodes[i], pp->skipped_nodes[i]);
979 pp->isamb->skipped_numbers += pp->skipped_numbers;
980 pp->isamb->returned_numbers += pp->returned_numbers;
981 for (i=pp->maxlevel;i>=0;i--)
983 pp->isamb->accessed_nodes[i] += pp->accessed_nodes[i];
984 pp->isamb->skipped_nodes[i] += pp->skipped_nodes[i];
987 *size = pp->total_size;
989 *blocks = pp->no_blocks;
990 for (i = 0; i <= pp->level; i++)
991 close_block (pp->isamb, pp->block[i]);
996 int isamb_block_info (ISAMB isamb, int cat)
998 if (cat >= 0 && cat < isamb->no_cat)
999 return isamb->file[cat].head.block_size;
1003 void isamb_pp_close (ISAMB_PP pp)
1005 isamb_pp_close_x (pp, 0, 0);
1010 /* Old isamb_pp_read that Adam wrote, kept as a reference in case we need to
1011 debug the more complex pp_read that also forwards. May be deleted near end
1012 of 2004, if it has not shown to be useful */
1014 int isamb_pp_read (ISAMB_PP pp, void *buf)
1018 struct ISAMB_block *p = pp->block[pp->level];
1022 while (p->offset == p->size)
1025 while (p->offset == p->size)
1029 close_block (pp->isamb, pp->block[pp->level]);
1030 pp->block[pp->level] = 0;
1032 p = pp->block[pp->level];
1035 src = p->bytes + p->offset;
1037 decode_ptr (&src, &item_len);
1039 decode_ptr (&src, &pos);
1041 p->offset = src - (char*) p->bytes;
1047 pp->block[pp->level] = p = open_block (pp->isamb, pos);
1049 pp->total_size += p->size;
1056 src = p->bytes + p->offset;
1057 decode_ptr (&src, &pos);
1058 p->offset = src - (char*) p->bytes;
1062 assert (p->offset < p->size);
1064 src = p->bytes + p->offset;
1065 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
1067 p->offset = src - (char*) p->bytes;
1068 /* key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1"); */
1073 int isamb_pp_read (ISAMB_PP pp, void *buf)
1075 return isamb_pp_forward(pp,buf,0);
1079 int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
1083 * while at end of node
1084 * climb higher. If out, return 0
1085 * while not on a leaf (and not at its end)
1094 * The upper nodes consist of a sequence of nodenumbers and keys
1095 * When opening a block, the first node number is read in, and
1096 * offset points to the first key, which is the upper limit of keys
1097 * in the node just read.
1101 struct ISAMB_block *p = pp->block[pp->level];
1106 int descending=0; /* used to prevent a border condition error */
1110 logf(LOG_DEBUG,"isamb_pp_forward starting [%p] p=%d",pp,p->pos);
1112 (*pp->isamb->method->log_item)(LOG_DEBUG, untilbuf, "until");
1113 (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "buf");
1118 while ( (p->offset == p->size) && !descending )
1119 { /* end of this block - climb higher */
1121 logf(LOG_DEBUG,"isamb_pp_forward climbing from l=%d",
1127 logf(LOG_DEBUG,"isamb_pp_forward returning 0 at root");
1129 return 0; /* at end of the root, nothing left */
1131 close_block(pp->isamb, pp->block[pp->level]);
1132 pp->block[pp->level]=0;
1134 p=pp->block[pp->level];
1136 logf(LOG_DEBUG,"isamb_pp_forward climbed to node %d off=%d",
1140 /* skip the child we have handled */
1141 if (p->offset != p->size)
1143 src = p->bytes + p->offset;
1144 decode_ptr(&src, &item_len);
1146 (*pp->isamb->method->log_item)(LOG_DEBUG, src,
1147 " isamb_pp_forward "
1148 "climb skipping old key");
1151 decode_ptr(&src,&pos);
1152 p->offset = src - (char*) p->bytes;
1153 break; /* even if this puts us at the end of the block, we need to */
1154 /* descend to the last pos. UGLY coding, clean up some */
1160 src = p->bytes + p->offset;
1161 if (p->offset == p->size)
1162 cmp=-2 ; /* descend to the last node, as we have no value to cmp */
1165 decode_ptr(&src, &item_len);
1167 logf(LOG_DEBUG,"isamb_pp_forward (B) on a high node. ofs=%d sz=%d nxtpos=%d ",
1168 p->offset,p->size,pos);
1169 (*pp->isamb->method->log_item)(LOG_DEBUG, src, "");
1172 cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
1176 decode_ptr(&src,&nxtpos);
1181 logf(LOG_DEBUG,"isambb_pp_forward descending l=%d p=%d ",
1184 descending=1; /* prevent climbing for a while */
1186 p = open_block(pp->isamb,pos);
1187 pp->block[pp->level] = p ;
1188 pp->total_size += p->size;
1189 (pp->accessed_nodes[pp->maxlevel - pp->level])++;
1192 { /* block starts with a pos */
1193 src = p->bytes + p->offset;
1194 decode_ptr(&src,&pos);
1195 p->offset=src-(char*) p->bytes;
1197 logf(LOG_DEBUG,"isamb_pp_forward: block %d starts with %d",
1201 } /* descend to the node */
1203 { /* skip the node */
1204 p->offset = src - (char*) p->bytes;
1206 (pp->skipped_nodes[pp->maxlevel - pp->level -1])++;
1209 "isamb_pp_forward: skipping block on level %d, noting on %d (%d)",
1210 pp->level, pp->maxlevel - pp->level-1 ,
1211 pp->skipped_nodes[pp->maxlevel - pp->level-1 ]);
1213 /* 0 is always leafs, 1 is one level above leafs etc, no
1214 * matter how high tree */
1216 } /* not on a leaf */
1219 src = p->bytes + p->offset;
1221 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
1223 p->offset = src - (char*) p->bytes;
1225 cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
1229 logf(LOG_DEBUG,"isamb_pp_forward on a leaf. cmp=%d",
1231 (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "");
1238 (*pp->isamb->method->log_item)(LOG_DEBUG, buf,
1239 "isamb_pp_forward returning 1");
1243 (*pp->isamb->method->log_item)(LOG_DEBUG, buf,
1244 "isamb_pp_read returning 1 (fwd)");
1247 pp->returned_numbers++;
1251 pp->skipped_numbers++;
1257 int isamb_pp_num (ISAMB_PP pp)