1 /* $Id: isamb.c,v 1.30 2004-06-01 12:56:38 adam 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>
37 #define ISAMB_DATA_OFFSET 3
39 /* maximum size of encoded buffer */
40 #define DST_ITEM_MAX 256
42 #define ISAMB_MAX_LEVEL 10
43 /* approx 2*max page + max size of item */
44 #define DST_BUF_SIZE 16840
46 #define ISAMB_CACHE_ENTRY_SIZE 4096
48 /* CAT_MAX: _must_ be power of 2 */
50 #define CAT_MASK (CAT_MAX-1)
51 /* CAT_NO: <= CAT_MAX */
54 /* ISAMB_PTR_CODEC=1 var, =0 fixed */
55 #define ISAMB_PTR_CODEC 1
57 struct ISAMB_cache_entry {
62 struct ISAMB_cache_entry *next;
68 struct ISAMB_head head;
69 struct ISAMB_cache_entry *cache_entries;
76 struct ISAMB_file *file;
78 int cache; /* 0=no cache, 1=use cache, -1=dummy isam (for testing only) */
79 int log_io; /* log level for bf_read/bf_write calls */
80 int log_freelist; /* log level for freelist handling */
81 int skipped_numbers; /* on a leaf node */
83 int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
84 int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
97 void *decodeClientData;
105 int maxlevel; /* total depth */
108 int skipped_numbers; /* on a leaf node */
109 int returned_numbers;
110 int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
111 int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
112 struct ISAMB_block **block;
116 static void encode_ptr (char **dst, unsigned pos)
118 unsigned char *bp = (unsigned char*) *dst;
122 *bp++ = 128 | (pos & 127);
129 static void encode_ptr (char **dst, unsigned pos)
131 memcpy(*dst, &pos, sizeof(pos));
132 (*dst) += sizeof(pos);
137 static void decode_ptr (char **src1, int *pos)
139 unsigned char **src = (unsigned char **) src1;
144 while (((c = *(*src)++) & 128))
146 d += ((c & 127) << r);
153 static void decode_ptr (char **src, int *pos)
155 memcpy (pos, *src, sizeof(*pos));
156 (*src) += sizeof(*pos);
160 ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method,
163 ISAMB isamb = xmalloc (sizeof(*isamb));
167 isamb->method = (ISAMC_M *) xmalloc (sizeof(*method));
168 memcpy (isamb->method, method, sizeof(*method));
169 isamb->no_cat = CAT_NO;
171 isamb->log_freelist = 0;
172 isamb->cache = cache;
173 isamb->skipped_numbers=0;
174 isamb->returned_numbers=0;
175 for (i=0;i<ISAMB_MAX_LEVEL;i++)
176 isamb->skipped_nodes[i]= isamb->accessed_nodes[i]=0;
179 isamb->file = xmalloc (sizeof(*isamb->file) * isamb->no_cat);
180 for (i = 0; i<isamb->no_cat; i++)
182 char fname[DST_BUF_SIZE];
183 isamb->file[i].cache_entries = 0;
184 isamb->file[i].head_dirty = 0;
185 sprintf (fname, "%s%c", name, i+'A');
187 isamb->file[i].bf = bf_open (bfs, fname, ISAMB_CACHE_ENTRY_SIZE,
190 isamb->file[i].bf = bf_open (bfs, fname, b_size, writeflag);
193 if (!bf_read (isamb->file[i].bf, 0, 0, sizeof(struct ISAMB_head),
194 &isamb->file[i].head))
196 isamb->file[i].head.first_block = ISAMB_CACHE_ENTRY_SIZE/b_size+1;
197 isamb->file[i].head.last_block = isamb->file[i].head.first_block;
198 isamb->file[i].head.block_size = b_size;
199 isamb->file[i].head.block_max = b_size - ISAMB_DATA_OFFSET;
200 isamb->file[i].head.free_list = 0;
202 assert (isamb->file[i].head.block_size >= ISAMB_DATA_OFFSET);
203 isamb->file[i].head_dirty = 0;
204 assert(isamb->file[i].head.block_size == b_size);
210 static void flush_blocks (ISAMB b, int cat)
212 while (b->file[cat].cache_entries)
214 struct ISAMB_cache_entry *ce_this = b->file[cat].cache_entries;
215 b->file[cat].cache_entries = ce_this->next;
219 yaz_log (b->log_io, "bf_write: flush_blocks");
220 bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
222 xfree (ce_this->buf);
227 static int get_block (ISAMB b, ISAMC_P pos, char *userbuf, int wr)
229 int cat = pos&CAT_MASK;
230 int off = ((pos/CAT_MAX) &
231 (ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size - 1))
232 * b->file[cat].head.block_size;
233 int norm = pos / (CAT_MASK*ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size);
235 struct ISAMB_cache_entry **ce, *ce_this = 0, **ce_last = 0;
240 assert (ISAMB_CACHE_ENTRY_SIZE >= b->file[cat].head.block_size);
241 for (ce = &b->file[cat].cache_entries; *ce; ce = &(*ce)->next, no++)
244 if ((*ce)->pos == norm)
247 *ce = (*ce)->next; /* remove from list */
249 ce_this->next = b->file[cat].cache_entries; /* move to front */
250 b->file[cat].cache_entries = ce_this;
254 memcpy (ce_this->buf + off, userbuf,
255 b->file[cat].head.block_size);
259 memcpy (userbuf, ce_this->buf + off,
260 b->file[cat].head.block_size);
267 assert (ce_last && *ce_last);
269 *ce_last = 0; /* remove the last entry from list */
272 yaz_log (b->log_io, "bf_write: get_block");
273 bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
275 xfree (ce_this->buf);
278 ce_this = xmalloc (sizeof(*ce_this));
279 ce_this->next = b->file[cat].cache_entries;
280 b->file[cat].cache_entries = ce_this;
281 ce_this->buf = xmalloc (ISAMB_CACHE_ENTRY_SIZE);
283 yaz_log (b->log_io, "bf_read: get_block");
284 if (!bf_read (b->file[cat].bf, norm, 0, 0, ce_this->buf))
285 memset (ce_this->buf, 0, ISAMB_CACHE_ENTRY_SIZE);
288 memcpy (ce_this->buf + off, userbuf, b->file[cat].head.block_size);
294 memcpy (userbuf, ce_this->buf + off, b->file[cat].head.block_size);
300 void isamb_close (ISAMB isamb)
303 for (i=0;isamb->accessed_nodes[i];i++)
304 logf(LOG_DEBUG,"isamb_close level leaf-%d: %d read, %d skipped",
305 i, isamb->accessed_nodes[i], isamb->skipped_nodes[i]);
306 logf(LOG_DEBUG,"isamb_close returned %d values, skipped %d",
307 isamb->skipped_numbers, isamb->returned_numbers);
308 for (i = 0; i<isamb->no_cat; i++)
310 flush_blocks (isamb, i);
311 if (isamb->file[i].head_dirty)
312 bf_write (isamb->file[i].bf, 0, 0,
313 sizeof(struct ISAMB_head), &isamb->file[i].head);
315 bf_close (isamb->file[i].bf);
318 xfree (isamb->method);
323 struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
325 int cat = pos&CAT_MASK;
326 struct ISAMB_block *p;
329 p = xmalloc (sizeof(*p));
331 p->cat = pos & CAT_MASK;
332 p->buf = xmalloc (b->file[cat].head.block_size);
334 if (!get_block (b, pos, p->buf, 0))
336 yaz_log (b->log_io, "bf_read: open_block");
337 if (!bf_read (b->file[cat].bf, pos/CAT_MAX, 0, 0, p->buf))
339 yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
340 (long) pos, (long) pos/CAT_MAX);
344 p->bytes = p->buf + ISAMB_DATA_OFFSET;
346 p->size = (p->buf[1] + 256 * p->buf[2]) - ISAMB_DATA_OFFSET;
349 yaz_log (LOG_FATAL, "Bad block size %d in pos=%d\n", p->size, pos);
351 assert (p->size >= 0);
355 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
356 yaz_log (LOG_DEBUG, "isamb_open_block: Opened block %d ofs=%d",pos, p->offset);
360 struct ISAMB_block *new_block (ISAMB b, int leaf, int cat)
362 struct ISAMB_block *p;
364 p = xmalloc (sizeof(*p));
365 p->buf = xmalloc (b->file[cat].head.block_size);
367 if (!b->file[cat].head.free_list)
370 block_no = b->file[cat].head.last_block++;
371 p->pos = block_no * CAT_MAX + cat;
375 p->pos = b->file[cat].head.free_list;
376 assert((p->pos & CAT_MASK) == cat);
377 if (!get_block (b, p->pos, p->buf, 0))
379 yaz_log (b->log_io, "bf_read: new_block");
380 if (!bf_read (b->file[cat].bf, p->pos/CAT_MAX, 0, 0, p->buf))
382 yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
383 (long) p->pos/CAT_MAX, (long) p->pos/CAT_MAX);
387 yaz_log (b->log_freelist, "got block %d from freelist %d:%d", p->pos,
388 cat, p->pos/CAT_MAX);
389 memcpy (&b->file[cat].head.free_list, p->buf, sizeof(int));
392 b->file[cat].head_dirty = 1;
393 memset (p->buf, 0, b->file[cat].head.block_size);
394 p->bytes = p->buf + ISAMB_DATA_OFFSET;
400 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
404 struct ISAMB_block *new_leaf (ISAMB b, int cat)
406 return new_block (b, 1, cat);
410 struct ISAMB_block *new_int (ISAMB b, int cat)
412 return new_block (b, 0, cat);
415 static void check_block (ISAMB b, struct ISAMB_block *p)
424 char *startp = p->bytes;
426 char *endp = p->bytes + p->size;
429 decode_ptr (&src, &pos);
430 assert ((pos&CAT_MASK) == p->cat);
434 decode_ptr (&src, &item_len);
435 assert (item_len > 0 && item_len < 30);
437 decode_ptr (&src, &pos);
438 assert ((pos&CAT_MASK) == p->cat);
443 void close_block (ISAMB b, struct ISAMB_block *p)
449 yaz_log (b->log_freelist, "release block %d from freelist %d:%d",
450 p->pos, p->cat, p->pos/CAT_MAX);
451 memcpy (p->buf, &b->file[p->cat].head.free_list, sizeof(int));
452 b->file[p->cat].head.free_list = p->pos;
453 if (!get_block (b, p->pos, p->buf, 1))
455 yaz_log (b->log_io, "bf_write: close_block (deleted)");
456 bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
461 int size = p->size + ISAMB_DATA_OFFSET;
462 assert (p->size >= 0);
464 p->buf[1] = size & 255;
465 p->buf[2] = size >> 8;
467 if (!get_block (b, p->pos, p->buf, 1))
469 yaz_log (b->log_io, "bf_write: close_block");
470 bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
473 (*b->method->code_stop)(ISAMC_DECODE, p->decodeClientData);
478 int insert_sub (ISAMB b, struct ISAMB_block **p,
479 void *new_item, int *mode,
481 struct ISAMB_block **sp,
482 void *sub_item, int *sub_size,
485 int insert_int (ISAMB b, struct ISAMB_block *p, void *lookahead_item,
487 ISAMC_I *stream, struct ISAMB_block **sp,
488 void *split_item, int *split_size, void *last_max_item)
490 char *startp = p->bytes;
492 char *endp = p->bytes + p->size;
494 struct ISAMB_block *sub_p1 = 0, *sub_p2 = 0;
495 char sub_item[DST_ITEM_MAX];
501 assert(p->size >= 0);
502 decode_ptr (&src, &pos);
508 decode_ptr (&src, &item_len);
509 d = (*b->method->compare_item)(src, lookahead_item);
512 sub_p1 = open_block (b, pos);
514 more = insert_sub (b, &sub_p1, lookahead_item, mode,
516 sub_item, &sub_size, src);
521 decode_ptr (&src, &pos);
525 sub_p1 = open_block (b, pos);
527 more = insert_sub (b, &sub_p1, lookahead_item, mode, stream, &sub_p2,
528 sub_item, &sub_size, last_max_item);
532 /* there was a split - must insert pointer in this one */
533 char dst_buf[DST_BUF_SIZE];
536 assert (sub_size < 30 && sub_size > 1);
538 memcpy (dst, startp, src - startp);
542 encode_ptr (&dst, sub_size); /* sub length and item */
543 memcpy (dst, sub_item, sub_size);
546 encode_ptr (&dst, sub_p2->pos); /* pos */
548 if (endp - src) /* remaining data */
550 memcpy (dst, src, endp - src);
553 p->size = dst - dst_buf;
554 assert (p->size >= 0);
555 if (p->size <= b->file[p->cat].head.block_max)
557 memcpy (startp, dst_buf, dst - dst_buf);
566 half = src + b->file[p->cat].head.block_size/2;
567 decode_ptr (&src, &pos);
570 decode_ptr (&src, split_size);
572 decode_ptr (&src, &pos);
574 p_new_size = src - dst_buf;
575 memcpy (p->bytes, dst_buf, p_new_size);
577 decode_ptr (&src, split_size);
578 memcpy (split_item, src, *split_size);
581 *sp = new_int (b, p->cat);
582 (*sp)->size = endp - src;
583 memcpy ((*sp)->bytes, src, (*sp)->size);
585 p->size = p_new_size;
588 close_block (b, sub_p2);
590 close_block (b, sub_p1);
595 int insert_leaf (ISAMB b, struct ISAMB_block **sp1, void *lookahead_item,
596 int *lookahead_mode, ISAMC_I *stream,
597 struct ISAMB_block **sp2,
598 void *sub_item, int *sub_size,
601 struct ISAMB_block *p = *sp1;
602 char *src = 0, *endp = 0;
603 char dst_buf[DST_BUF_SIZE], *dst = dst_buf;
605 void *c1 = (*b->method->code_start)(ISAMC_DECODE);
606 void *c2 = (*b->method->code_start)(ISAMC_ENCODE);
608 int quater = b->file[b->no_cat-1].head.block_max / CAT_MAX;
609 char *cut = dst_buf + quater * 2;
610 char *maxp = dst_buf + b->file[b->no_cat-1].head.block_max;
613 char cut_item_buf[DST_ITEM_MAX];
614 int cut_item_size = 0;
618 char file_item_buf[DST_ITEM_MAX];
619 char *file_item = file_item_buf;
622 endp = p->bytes + p->size;
623 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
628 char *lookahead_next;
632 d = (*b->method->compare_item)(file_item_buf, lookahead_item);
636 dst_item = lookahead_item;
637 if (!*lookahead_mode)
639 yaz_log (LOG_WARN, "isamb: Inconsistent register (1)");
640 assert (*lookahead_mode);
644 dst_item = file_item_buf;
645 if (!*lookahead_mode && d == 0)
649 else if (!half1 && dst > cut)
651 char *dst_item_0 = dst_item;
652 half1 = dst; /* candidate for splitting */
654 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
656 cut_item_size = dst_item - dst_item_0;
657 memcpy (cut_item_buf, dst_item_0, cut_item_size);
662 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
672 lookahead_next = lookahead_item;
673 if (!(*stream->read_item)(stream->clientData,
680 if (lookahead_item && max_item &&
681 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
692 lookahead_next = lookahead_item;
693 if (!(*stream->read_item)(stream->clientData,
694 &lookahead_next, lookahead_mode))
701 file_item = file_item_buf;
702 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
708 file_item = file_item_buf;
709 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
713 maxp = dst_buf + b->file[b->no_cat-1].head.block_max + quater;
714 while (lookahead_item)
716 char *dst_item = lookahead_item;
720 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
725 if (!*lookahead_mode)
727 yaz_log (LOG_WARN, "isamb: Inconsistent register (2)");
730 else if (!half1 && dst > cut)
732 char *dst_item_0 = dst_item;
733 half1 = dst; /* candidate for splitting */
735 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
737 cut_item_size = dst_item - dst_item_0;
738 memcpy (cut_item_buf, dst_item_0, cut_item_size);
743 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
752 dst_item = lookahead_item;
753 if (!(*stream->read_item)(stream->clientData, &dst_item,
760 new_size = dst - dst_buf;
761 if (p && p->cat != b->no_cat-1 &&
762 new_size > b->file[p->cat].head.block_max)
764 /* non-btree block will be removed */
767 /* delete it too!! */
768 p = 0; /* make a new one anyway */
771 { /* must create a new one */
773 for (i = 0; i < b->no_cat; i++)
774 if (new_size <= b->file[i].head.block_max)
780 if (new_size > b->file[p->cat].head.block_max)
783 char *cut_item = cut_item_buf;
789 p->size = half1 - dst_buf;
790 memcpy (p->bytes, dst_buf, half1 - dst_buf);
793 *sp2 = new_leaf (b, p->cat);
795 (*b->method->code_reset)(c2);
797 first_dst = (*sp2)->bytes;
799 (*b->method->code_item)(ISAMC_ENCODE, c2, &first_dst, &cut_item);
801 memcpy (first_dst, half2, dst - half2);
803 (*sp2)->size = (first_dst - (*sp2)->bytes) + (dst - half2);
806 memcpy (sub_item, cut_item_buf, cut_item_size);
807 *sub_size = cut_item_size;
811 memcpy (p->bytes, dst_buf, dst - dst_buf);
814 (*b->method->code_stop)(ISAMC_DECODE, c1);
815 (*b->method->code_stop)(ISAMC_ENCODE, c2);
820 int insert_sub (ISAMB b, struct ISAMB_block **p, void *new_item,
823 struct ISAMB_block **sp,
824 void *sub_item, int *sub_size,
827 if (!*p || (*p)->leaf)
828 return insert_leaf (b, p, new_item, mode, stream, sp, sub_item,
831 return insert_int (b, *p, new_item, mode, stream, sp, sub_item,
835 int isamb_unlink (ISAMB b, ISAMC_P pos)
837 struct ISAMB_block *p1;
841 p1 = open_block(b, pos);
847 char *src = p1->bytes + p1->offset;
849 decode_ptr(&src, &sub_p);
850 isamb_unlink(b, sub_p);
852 while (src != p1->bytes + p1->size)
854 decode_ptr(&src, &item_len);
856 decode_ptr(&src, &sub_p);
857 isamb_unlink(b, sub_p);
864 int isamb_merge (ISAMB b, ISAMC_P pos, ISAMC_I *stream)
866 char item_buf[DST_ITEM_MAX];
878 (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
883 more = (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
886 struct ISAMB_block *p = 0, *sp = 0;
887 char sub_item[DST_ITEM_MAX];
891 p = open_block (b, pos);
892 more = insert_sub (b, &p, item_buf, &i_mode, stream, &sp,
893 sub_item, &sub_size, 0);
895 { /* increase level of tree by one */
896 struct ISAMB_block *p2 = new_int (b, p->cat);
897 char *dst = p2->bytes + p2->size;
899 encode_ptr (&dst, p->pos);
900 assert (sub_size < 20);
901 encode_ptr (&dst, sub_size);
902 memcpy (dst, sub_item, sub_size);
904 encode_ptr (&dst, sp->pos);
906 p2->size = dst - p2->bytes;
907 pos = p2->pos; /* return new super page */
912 pos = p->pos; /* return current one (again) */
918 ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
920 ISAMB_PP pp = xmalloc (sizeof(*pp));
924 pp->block = xmalloc (ISAMB_MAX_LEVEL * sizeof(*pp->block));
931 pp->skipped_numbers=0;
932 pp->returned_numbers=0;
933 for (i=0;i<ISAMB_MAX_LEVEL;i++)
934 pp->skipped_nodes[i] = pp->accessed_nodes[i]=0;
937 struct ISAMB_block *p = open_block (isamb, pos);
938 char *src = p->bytes + p->offset;
939 pp->block[pp->level] = p;
941 pp->total_size += p->size;
947 decode_ptr (&src, &pos);
948 p->offset = src - p->bytes;
950 pp->accessed_nodes[pp->level]++;
952 pp->block[pp->level+1] = 0;
953 pp->maxlevel=pp->level;
959 ISAMB_PP isamb_pp_open (ISAMB isamb, ISAMB_P pos)
961 return isamb_pp_open_x (isamb, pos, 0);
964 void isamb_pp_close_x (ISAMB_PP pp, int *size, int *blocks)
969 logf(LOG_DEBUG,"isamb_pp_close lev=%d returned %d values, skipped %d",
970 pp->maxlevel, pp->skipped_numbers, pp->returned_numbers);
971 for (i=pp->maxlevel;i>=0;i--)
972 if ( pp->skipped_nodes[i] || pp->accessed_nodes[i])
973 logf(LOG_DEBUG,"isamb_pp_close level leaf-%d: %d read, %d skipped", i,
974 pp->accessed_nodes[i], pp->skipped_nodes[i]);
975 pp->isamb->skipped_numbers += pp->skipped_numbers;
976 pp->isamb->returned_numbers += pp->returned_numbers;
977 for (i=pp->maxlevel;i>=0;i--)
979 pp->isamb->accessed_nodes[i] += pp->accessed_nodes[i];
980 pp->isamb->skipped_nodes[i] += pp->skipped_nodes[i];
983 *size = pp->total_size;
985 *blocks = pp->no_blocks;
986 for (i = 0; i <= pp->level; i++)
987 close_block (pp->isamb, pp->block[i]);
992 int isamb_block_info (ISAMB isamb, int cat)
994 if (cat >= 0 && cat < isamb->no_cat)
995 return isamb->file[cat].head.block_size;
999 void isamb_pp_close (ISAMB_PP pp)
1001 isamb_pp_close_x (pp, 0, 0);
1006 /* Old isamb_pp_read that Adam wrote, kept as a reference in case we need to
1007 debug the more complex pp_read that also forwards. May be deleted near end
1008 of 2004, if it has not shown to be useful */
1010 int isamb_pp_read (ISAMB_PP pp, void *buf)
1014 struct ISAMB_block *p = pp->block[pp->level];
1018 while (p->offset == p->size)
1021 while (p->offset == p->size)
1025 close_block (pp->isamb, pp->block[pp->level]);
1026 pp->block[pp->level] = 0;
1028 p = pp->block[pp->level];
1031 src = p->bytes + p->offset;
1033 decode_ptr (&src, &item_len);
1035 decode_ptr (&src, &pos);
1037 p->offset = src - (char*) p->bytes;
1043 pp->block[pp->level] = p = open_block (pp->isamb, pos);
1045 pp->total_size += p->size;
1052 src = p->bytes + p->offset;
1053 decode_ptr (&src, &pos);
1054 p->offset = src - (char*) p->bytes;
1058 assert (p->offset < p->size);
1060 src = p->bytes + p->offset;
1061 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
1063 p->offset = src - (char*) p->bytes;
1064 key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1");
1069 int isamb_pp_read (ISAMB_PP pp, void *buf)
1071 return isamb_pp_forward(pp,buf,0);
1075 int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
1079 * while at end of node
1080 * climb higher. If out, return 0
1081 * while not on a leaf (and not at its end)
1090 * The upper nodes consist of a sequence of nodenumbers and keys
1091 * When opening a block, the first node number is read in, and
1092 * offset points to the first key, which is the upper limit of keys
1093 * in the node just read.
1097 struct ISAMB_block *p = pp->block[pp->level];
1104 logf(LOG_DEBUG,"isamb_pp_forward starting [%p] p=%d",pp,p->pos);
1106 (*pp->isamb->method->log_item)(LOG_DEBUG, untilbuf, "until");
1107 (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "buf");
1111 while ( p->offset == p->size)
1112 { /* end of this block - climb higher */
1113 logf(LOG_DEBUG,"isamb_pp_forward climbing from l=%d",
1117 logf(LOG_DEBUG,"isamb_pp_forward returning 0 at root");
1118 return 0; /* at end of the root, nothing left */
1120 close_block(pp->isamb, pp->block[pp->level]);
1121 pp->block[pp->level]=0;
1123 p=pp->block[pp->level];
1124 logf(LOG_DEBUG,"isamb_pp_forward climbed to node %d off=%d",
1127 /* skip the child we have handled */
1128 if (p->offset != p->size)
1130 src = p->bytes + p->offset;
1131 decode_ptr(&src, &item_len);
1133 (*pp->isamb->method->log_item)(LOG_DEBUG, src,
1134 " isamb_pp_forward "
1135 "climb skipping old key");
1137 decode_ptr(&src,&pos);
1138 p->offset = src - (char*) p->bytes;
1139 break; /* even if this puts us at the end of the block, we need to */
1140 /* descend to the last pos. UGLY coding, clean up some */
1146 src = p->bytes + p->offset;
1147 if (p->offset == p->size)
1148 cmp=-2 ; /* descend to the last node, as we have no value to cmp */
1151 decode_ptr(&src, &item_len);
1152 logf(LOG_DEBUG,"isamb_pp_forward (B) on a high node. ofs=%d sz=%d nxtpos=%d ",
1153 p->offset,p->size,pos);
1156 (*pp->isamb->method->log_item)(LOG_DEBUG, src, "");
1158 cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
1162 decode_ptr(&src,&nxtpos);
1166 logf(LOG_DEBUG,"isambb_pp_forward descending l=%d p=%d ",
1169 p = open_block(pp->isamb,pos);
1170 pp->block[pp->level] = p ;
1171 pp->total_size += p->size;
1172 (pp->accessed_nodes[pp->maxlevel - pp->level])++;
1175 { /* block starts with a pos */
1176 src = p->bytes + p->offset;
1177 decode_ptr(&src,&pos);
1178 p->offset=src-(char*) p->bytes;
1179 logf(LOG_DEBUG,"isamb_pp_forward: block %d starts with %d",
1182 } /* descend to the node */
1184 { /* skip the node */
1185 p->offset = src - (char*) p->bytes;
1187 (pp->skipped_nodes[pp->maxlevel - pp->level -1])++;
1189 "isamb_pp_forward: skipping block on level %d, noting on %d (%d)",
1190 pp->level, pp->maxlevel - pp->level-1 ,
1191 pp->skipped_nodes[pp->maxlevel - pp->level-1 ]);
1192 /* 0 is always leafs, 1 is one level above leafs etc, no
1193 * matter how high tree */
1195 } /* not on a leaf */
1198 src = p->bytes + p->offset;
1200 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
1202 p->offset = src - (char*) p->bytes;
1204 cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
1207 logf(LOG_DEBUG,"isamb_pp_forward on a leaf. cmp=%d",
1209 (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "");
1215 (*pp->isamb->method->log_item)(LOG_DEBUG, buf,
1216 "isamb_pp_forward returning 1");
1220 (*pp->isamb->method->log_item)(LOG_DEBUG, buf,
1221 "isamb_pp_read returning 1 (fwd)");
1223 pp->returned_numbers++;
1227 pp->skipped_numbers++;
1233 int isamb_pp_num (ISAMB_PP pp)