1 /* $Id: isamb.c,v 1.29 2004-06-01 12:32:19 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>
28 #include <../index/index.h> /* for log_keydump. Debugging only */
38 #define ISAMB_DATA_OFFSET 3
40 /* maximum size of encoded buffer */
41 #define DST_ITEM_MAX 256
43 #define ISAMB_MAX_LEVEL 10
44 /* approx 2*max page + max size of item */
45 #define DST_BUF_SIZE 16840
47 #define ISAMB_CACHE_ENTRY_SIZE 4096
49 /* CAT_MAX: _must_ be power of 2 */
51 #define CAT_MASK (CAT_MAX-1)
52 /* CAT_NO: <= CAT_MAX */
55 /* ISAMB_PTR_CODEC=1 var, =0 fixed */
56 #define ISAMB_PTR_CODEC 1
58 struct ISAMB_cache_entry {
63 struct ISAMB_cache_entry *next;
69 struct ISAMB_head head;
70 struct ISAMB_cache_entry *cache_entries;
77 struct ISAMB_file *file;
79 int cache; /* 0=no cache, 1=use cache, -1=dummy isam (for testing only) */
80 int log_io; /* log level for bf_read/bf_write calls */
81 int log_freelist; /* log level for freelist handling */
82 int skipped_numbers; /* on a leaf node */
84 int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
85 int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
98 void *decodeClientData;
106 int maxlevel; /* total depth */
109 int skipped_numbers; /* on a leaf node */
110 int returned_numbers;
111 int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
112 int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
113 struct ISAMB_block **block;
117 static void encode_ptr (char **dst, unsigned pos)
119 unsigned char *bp = (unsigned char*) *dst;
123 *bp++ = 128 | (pos & 127);
130 static void encode_ptr (char **dst, unsigned pos)
132 memcpy(*dst, &pos, sizeof(pos));
133 (*dst) += sizeof(pos);
138 static void decode_ptr (char **src1, int *pos)
140 unsigned char **src = (unsigned char **) src1;
145 while (((c = *(*src)++) & 128))
147 d += ((c & 127) << r);
154 static void decode_ptr (char **src, int *pos)
156 memcpy (pos, *src, sizeof(*pos));
157 (*src) += sizeof(*pos);
161 ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method,
164 ISAMB isamb = xmalloc (sizeof(*isamb));
168 isamb->method = (ISAMC_M *) xmalloc (sizeof(*method));
169 memcpy (isamb->method, method, sizeof(*method));
170 isamb->no_cat = CAT_NO;
172 isamb->log_freelist = 0;
173 isamb->cache = cache;
174 isamb->skipped_numbers=0;
175 isamb->returned_numbers=0;
176 for (i=0;i<ISAMB_MAX_LEVEL;i++)
177 isamb->skipped_nodes[i]= isamb->accessed_nodes[i]=0;
180 isamb->file = xmalloc (sizeof(*isamb->file) * isamb->no_cat);
181 for (i = 0; i<isamb->no_cat; i++)
183 char fname[DST_BUF_SIZE];
184 isamb->file[i].cache_entries = 0;
185 isamb->file[i].head_dirty = 0;
186 sprintf (fname, "%s%c", name, i+'A');
188 isamb->file[i].bf = bf_open (bfs, fname, ISAMB_CACHE_ENTRY_SIZE,
191 isamb->file[i].bf = bf_open (bfs, fname, b_size, writeflag);
194 if (!bf_read (isamb->file[i].bf, 0, 0, sizeof(struct ISAMB_head),
195 &isamb->file[i].head))
197 isamb->file[i].head.first_block = ISAMB_CACHE_ENTRY_SIZE/b_size+1;
198 isamb->file[i].head.last_block = isamb->file[i].head.first_block;
199 isamb->file[i].head.block_size = b_size;
200 isamb->file[i].head.block_max = b_size - ISAMB_DATA_OFFSET;
201 isamb->file[i].head.free_list = 0;
203 assert (isamb->file[i].head.block_size >= ISAMB_DATA_OFFSET);
204 isamb->file[i].head_dirty = 0;
205 assert(isamb->file[i].head.block_size == b_size);
211 static void flush_blocks (ISAMB b, int cat)
213 while (b->file[cat].cache_entries)
215 struct ISAMB_cache_entry *ce_this = b->file[cat].cache_entries;
216 b->file[cat].cache_entries = ce_this->next;
220 yaz_log (b->log_io, "bf_write: flush_blocks");
221 bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
223 xfree (ce_this->buf);
228 static int get_block (ISAMB b, ISAMC_P pos, char *userbuf, int wr)
230 int cat = pos&CAT_MASK;
231 int off = ((pos/CAT_MAX) &
232 (ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size - 1))
233 * b->file[cat].head.block_size;
234 int norm = pos / (CAT_MASK*ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size);
236 struct ISAMB_cache_entry **ce, *ce_this = 0, **ce_last = 0;
241 assert (ISAMB_CACHE_ENTRY_SIZE >= b->file[cat].head.block_size);
242 for (ce = &b->file[cat].cache_entries; *ce; ce = &(*ce)->next, no++)
245 if ((*ce)->pos == norm)
248 *ce = (*ce)->next; /* remove from list */
250 ce_this->next = b->file[cat].cache_entries; /* move to front */
251 b->file[cat].cache_entries = ce_this;
255 memcpy (ce_this->buf + off, userbuf,
256 b->file[cat].head.block_size);
260 memcpy (userbuf, ce_this->buf + off,
261 b->file[cat].head.block_size);
268 assert (ce_last && *ce_last);
270 *ce_last = 0; /* remove the last entry from list */
273 yaz_log (b->log_io, "bf_write: get_block");
274 bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
276 xfree (ce_this->buf);
279 ce_this = xmalloc (sizeof(*ce_this));
280 ce_this->next = b->file[cat].cache_entries;
281 b->file[cat].cache_entries = ce_this;
282 ce_this->buf = xmalloc (ISAMB_CACHE_ENTRY_SIZE);
284 yaz_log (b->log_io, "bf_read: get_block");
285 if (!bf_read (b->file[cat].bf, norm, 0, 0, ce_this->buf))
286 memset (ce_this->buf, 0, ISAMB_CACHE_ENTRY_SIZE);
289 memcpy (ce_this->buf + off, userbuf, b->file[cat].head.block_size);
295 memcpy (userbuf, ce_this->buf + off, b->file[cat].head.block_size);
301 void isamb_close (ISAMB isamb)
304 for (i=0;isamb->accessed_nodes[i];i++)
305 logf(LOG_DEBUG,"isamb_close level leaf-%d: %d read, %d skipped",
306 i, isamb->accessed_nodes[i], isamb->skipped_nodes[i]);
307 logf(LOG_DEBUG,"isamb_close returned %d values, skipped %d",
308 isamb->skipped_numbers, isamb->returned_numbers);
309 for (i = 0; i<isamb->no_cat; i++)
311 flush_blocks (isamb, i);
312 if (isamb->file[i].head_dirty)
313 bf_write (isamb->file[i].bf, 0, 0,
314 sizeof(struct ISAMB_head), &isamb->file[i].head);
316 bf_close (isamb->file[i].bf);
319 xfree (isamb->method);
324 struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
326 int cat = pos&CAT_MASK;
327 struct ISAMB_block *p;
330 p = xmalloc (sizeof(*p));
332 p->cat = pos & CAT_MASK;
333 p->buf = xmalloc (b->file[cat].head.block_size);
335 if (!get_block (b, pos, p->buf, 0))
337 yaz_log (b->log_io, "bf_read: open_block");
338 if (!bf_read (b->file[cat].bf, pos/CAT_MAX, 0, 0, p->buf))
340 yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
341 (long) pos, (long) pos/CAT_MAX);
345 p->bytes = p->buf + ISAMB_DATA_OFFSET;
347 p->size = (p->buf[1] + 256 * p->buf[2]) - ISAMB_DATA_OFFSET;
350 yaz_log (LOG_FATAL, "Bad block size %d in pos=%d\n", p->size, pos);
352 assert (p->size >= 0);
356 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
357 yaz_log (LOG_DEBUG, "isamb_open_block: Opened block %d ofs=%d",pos, p->offset);
361 struct ISAMB_block *new_block (ISAMB b, int leaf, int cat)
363 struct ISAMB_block *p;
365 p = xmalloc (sizeof(*p));
366 p->buf = xmalloc (b->file[cat].head.block_size);
368 if (!b->file[cat].head.free_list)
371 block_no = b->file[cat].head.last_block++;
372 p->pos = block_no * CAT_MAX + cat;
376 p->pos = b->file[cat].head.free_list;
377 assert((p->pos & CAT_MASK) == cat);
378 if (!get_block (b, p->pos, p->buf, 0))
380 yaz_log (b->log_io, "bf_read: new_block");
381 if (!bf_read (b->file[cat].bf, p->pos/CAT_MAX, 0, 0, p->buf))
383 yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
384 (long) p->pos/CAT_MAX, (long) p->pos/CAT_MAX);
388 yaz_log (b->log_freelist, "got block %d from freelist %d:%d", p->pos,
389 cat, p->pos/CAT_MAX);
390 memcpy (&b->file[cat].head.free_list, p->buf, sizeof(int));
393 b->file[cat].head_dirty = 1;
394 memset (p->buf, 0, b->file[cat].head.block_size);
395 p->bytes = p->buf + ISAMB_DATA_OFFSET;
401 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
405 struct ISAMB_block *new_leaf (ISAMB b, int cat)
407 return new_block (b, 1, cat);
411 struct ISAMB_block *new_int (ISAMB b, int cat)
413 return new_block (b, 0, cat);
416 static void check_block (ISAMB b, struct ISAMB_block *p)
425 char *startp = p->bytes;
427 char *endp = p->bytes + p->size;
430 decode_ptr (&src, &pos);
431 assert ((pos&CAT_MASK) == p->cat);
435 decode_ptr (&src, &item_len);
436 assert (item_len > 0 && item_len < 30);
438 decode_ptr (&src, &pos);
439 assert ((pos&CAT_MASK) == p->cat);
444 void close_block (ISAMB b, struct ISAMB_block *p)
450 yaz_log (b->log_freelist, "release block %d from freelist %d:%d",
451 p->pos, p->cat, p->pos/CAT_MAX);
452 memcpy (p->buf, &b->file[p->cat].head.free_list, sizeof(int));
453 b->file[p->cat].head.free_list = p->pos;
454 if (!get_block (b, p->pos, p->buf, 1))
456 yaz_log (b->log_io, "bf_write: close_block (deleted)");
457 bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
462 int size = p->size + ISAMB_DATA_OFFSET;
463 assert (p->size >= 0);
465 p->buf[1] = size & 255;
466 p->buf[2] = size >> 8;
468 if (!get_block (b, p->pos, p->buf, 1))
470 yaz_log (b->log_io, "bf_write: close_block");
471 bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
474 (*b->method->code_stop)(ISAMC_DECODE, p->decodeClientData);
479 int insert_sub (ISAMB b, struct ISAMB_block **p,
480 void *new_item, int *mode,
482 struct ISAMB_block **sp,
483 void *sub_item, int *sub_size,
486 int insert_int (ISAMB b, struct ISAMB_block *p, void *lookahead_item,
488 ISAMC_I *stream, struct ISAMB_block **sp,
489 void *split_item, int *split_size, void *last_max_item)
491 char *startp = p->bytes;
493 char *endp = p->bytes + p->size;
495 struct ISAMB_block *sub_p1 = 0, *sub_p2 = 0;
496 char sub_item[DST_ITEM_MAX];
502 assert(p->size >= 0);
503 decode_ptr (&src, &pos);
509 decode_ptr (&src, &item_len);
510 d = (*b->method->compare_item)(src, lookahead_item);
513 sub_p1 = open_block (b, pos);
515 more = insert_sub (b, &sub_p1, lookahead_item, mode,
517 sub_item, &sub_size, src);
522 decode_ptr (&src, &pos);
526 sub_p1 = open_block (b, pos);
528 more = insert_sub (b, &sub_p1, lookahead_item, mode, stream, &sub_p2,
529 sub_item, &sub_size, last_max_item);
533 /* there was a split - must insert pointer in this one */
534 char dst_buf[DST_BUF_SIZE];
537 assert (sub_size < 30 && sub_size > 1);
539 memcpy (dst, startp, src - startp);
543 encode_ptr (&dst, sub_size); /* sub length and item */
544 memcpy (dst, sub_item, sub_size);
547 encode_ptr (&dst, sub_p2->pos); /* pos */
549 if (endp - src) /* remaining data */
551 memcpy (dst, src, endp - src);
554 p->size = dst - dst_buf;
555 assert (p->size >= 0);
556 if (p->size <= b->file[p->cat].head.block_max)
558 memcpy (startp, dst_buf, dst - dst_buf);
567 half = src + b->file[p->cat].head.block_size/2;
568 decode_ptr (&src, &pos);
571 decode_ptr (&src, split_size);
573 decode_ptr (&src, &pos);
575 p_new_size = src - dst_buf;
576 memcpy (p->bytes, dst_buf, p_new_size);
578 decode_ptr (&src, split_size);
579 memcpy (split_item, src, *split_size);
582 *sp = new_int (b, p->cat);
583 (*sp)->size = endp - src;
584 memcpy ((*sp)->bytes, src, (*sp)->size);
586 p->size = p_new_size;
589 close_block (b, sub_p2);
591 close_block (b, sub_p1);
596 int insert_leaf (ISAMB b, struct ISAMB_block **sp1, void *lookahead_item,
597 int *lookahead_mode, ISAMC_I *stream,
598 struct ISAMB_block **sp2,
599 void *sub_item, int *sub_size,
602 struct ISAMB_block *p = *sp1;
603 char *src = 0, *endp = 0;
604 char dst_buf[DST_BUF_SIZE], *dst = dst_buf;
606 void *c1 = (*b->method->code_start)(ISAMC_DECODE);
607 void *c2 = (*b->method->code_start)(ISAMC_ENCODE);
609 int quater = b->file[b->no_cat-1].head.block_max / CAT_MAX;
610 char *cut = dst_buf + quater * 2;
611 char *maxp = dst_buf + b->file[b->no_cat-1].head.block_max;
614 char cut_item_buf[DST_ITEM_MAX];
615 int cut_item_size = 0;
619 char file_item_buf[DST_ITEM_MAX];
620 char *file_item = file_item_buf;
623 endp = p->bytes + p->size;
624 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
629 char *lookahead_next;
633 d = (*b->method->compare_item)(file_item_buf, lookahead_item);
637 dst_item = lookahead_item;
638 if (!*lookahead_mode)
640 yaz_log (LOG_WARN, "isamb: Inconsistent register (1)");
641 assert (*lookahead_mode);
645 dst_item = file_item_buf;
646 if (!*lookahead_mode && d == 0)
650 else if (!half1 && dst > cut)
652 char *dst_item_0 = dst_item;
653 half1 = dst; /* candidate for splitting */
655 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
657 cut_item_size = dst_item - dst_item_0;
658 memcpy (cut_item_buf, dst_item_0, cut_item_size);
663 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
673 lookahead_next = lookahead_item;
674 if (!(*stream->read_item)(stream->clientData,
681 if (lookahead_item && max_item &&
682 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
693 lookahead_next = lookahead_item;
694 if (!(*stream->read_item)(stream->clientData,
695 &lookahead_next, lookahead_mode))
702 file_item = file_item_buf;
703 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
709 file_item = file_item_buf;
710 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
714 maxp = dst_buf + b->file[b->no_cat-1].head.block_max + quater;
715 while (lookahead_item)
717 char *dst_item = lookahead_item;
721 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
726 if (!*lookahead_mode)
728 yaz_log (LOG_WARN, "isamb: Inconsistent register (2)");
731 else if (!half1 && dst > cut)
733 char *dst_item_0 = dst_item;
734 half1 = dst; /* candidate for splitting */
736 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
738 cut_item_size = dst_item - dst_item_0;
739 memcpy (cut_item_buf, dst_item_0, cut_item_size);
744 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
753 dst_item = lookahead_item;
754 if (!(*stream->read_item)(stream->clientData, &dst_item,
761 new_size = dst - dst_buf;
762 if (p && p->cat != b->no_cat-1 &&
763 new_size > b->file[p->cat].head.block_max)
765 /* non-btree block will be removed */
768 /* delete it too!! */
769 p = 0; /* make a new one anyway */
772 { /* must create a new one */
774 for (i = 0; i < b->no_cat; i++)
775 if (new_size <= b->file[i].head.block_max)
781 if (new_size > b->file[p->cat].head.block_max)
784 char *cut_item = cut_item_buf;
790 p->size = half1 - dst_buf;
791 memcpy (p->bytes, dst_buf, half1 - dst_buf);
794 *sp2 = new_leaf (b, p->cat);
796 (*b->method->code_reset)(c2);
798 first_dst = (*sp2)->bytes;
800 (*b->method->code_item)(ISAMC_ENCODE, c2, &first_dst, &cut_item);
802 memcpy (first_dst, half2, dst - half2);
804 (*sp2)->size = (first_dst - (*sp2)->bytes) + (dst - half2);
807 memcpy (sub_item, cut_item_buf, cut_item_size);
808 *sub_size = cut_item_size;
812 memcpy (p->bytes, dst_buf, dst - dst_buf);
815 (*b->method->code_stop)(ISAMC_DECODE, c1);
816 (*b->method->code_stop)(ISAMC_ENCODE, c2);
821 int insert_sub (ISAMB b, struct ISAMB_block **p, void *new_item,
824 struct ISAMB_block **sp,
825 void *sub_item, int *sub_size,
828 if (!*p || (*p)->leaf)
829 return insert_leaf (b, p, new_item, mode, stream, sp, sub_item,
832 return insert_int (b, *p, new_item, mode, stream, sp, sub_item,
836 int isamb_unlink (ISAMB b, ISAMC_P pos)
838 struct ISAMB_block *p1;
842 p1 = open_block(b, pos);
848 char *src = p1->bytes + p1->offset;
850 decode_ptr(&src, &sub_p);
851 isamb_unlink(b, sub_p);
853 while (src != p1->bytes + p1->size)
855 decode_ptr(&src, &item_len);
857 decode_ptr(&src, &sub_p);
858 isamb_unlink(b, sub_p);
865 int isamb_merge (ISAMB b, ISAMC_P pos, ISAMC_I *stream)
867 char item_buf[DST_ITEM_MAX];
879 (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
884 more = (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
887 struct ISAMB_block *p = 0, *sp = 0;
888 char sub_item[DST_ITEM_MAX];
892 p = open_block (b, pos);
893 more = insert_sub (b, &p, item_buf, &i_mode, stream, &sp,
894 sub_item, &sub_size, 0);
896 { /* increase level of tree by one */
897 struct ISAMB_block *p2 = new_int (b, p->cat);
898 char *dst = p2->bytes + p2->size;
900 encode_ptr (&dst, p->pos);
901 assert (sub_size < 20);
902 encode_ptr (&dst, sub_size);
903 memcpy (dst, sub_item, sub_size);
905 encode_ptr (&dst, sp->pos);
907 p2->size = dst - p2->bytes;
908 pos = p2->pos; /* return new super page */
913 pos = p->pos; /* return current one (again) */
919 ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
921 ISAMB_PP pp = xmalloc (sizeof(*pp));
925 pp->block = xmalloc (ISAMB_MAX_LEVEL * sizeof(*pp->block));
932 pp->skipped_numbers=0;
933 pp->returned_numbers=0;
934 for (i=0;i<ISAMB_MAX_LEVEL;i++)
935 pp->skipped_nodes[i] = pp->accessed_nodes[i]=0;
938 struct ISAMB_block *p = open_block (isamb, pos);
939 char *src = p->bytes + p->offset;
940 pp->block[pp->level] = p;
942 pp->total_size += p->size;
948 decode_ptr (&src, &pos);
949 p->offset = src - p->bytes;
951 pp->accessed_nodes[pp->level]++;
953 pp->block[pp->level+1] = 0;
954 pp->maxlevel=pp->level;
960 ISAMB_PP isamb_pp_open (ISAMB isamb, ISAMB_P pos)
962 return isamb_pp_open_x (isamb, pos, 0);
965 void isamb_pp_close_x (ISAMB_PP pp, int *size, int *blocks)
970 logf(LOG_DEBUG,"isamb_pp_close lev=%d returned %d values, skipped %d",
971 pp->maxlevel, pp->skipped_numbers, pp->returned_numbers);
972 for (i=pp->maxlevel;i>=0;i--)
973 if ( pp->skipped_nodes[i] || pp->accessed_nodes[i])
974 logf(LOG_DEBUG,"isamb_pp_close level leaf-%d: %d read, %d skipped", i,
975 pp->accessed_nodes[i], pp->skipped_nodes[i]);
976 pp->isamb->skipped_numbers += pp->skipped_numbers;
977 pp->isamb->returned_numbers += pp->returned_numbers;
978 for (i=pp->maxlevel;i>=0;i--)
980 pp->isamb->accessed_nodes[i] += pp->accessed_nodes[i];
981 pp->isamb->skipped_nodes[i] += pp->skipped_nodes[i];
984 *size = pp->total_size;
986 *blocks = pp->no_blocks;
987 for (i = 0; i <= pp->level; i++)
988 close_block (pp->isamb, pp->block[i]);
993 int isamb_block_info (ISAMB isamb, int cat)
995 if (cat >= 0 && cat < isamb->no_cat)
996 return isamb->file[cat].head.block_size;
1000 void isamb_pp_close (ISAMB_PP pp)
1002 isamb_pp_close_x (pp, 0, 0);
1007 /* Old isamb_pp_read that Adam wrote, kept as a reference in case we need to
1008 debug the more complex pp_read that also forwards. May be deleted near end
1009 of 2004, if it has not shown to be useful */
1011 int isamb_pp_read (ISAMB_PP pp, void *buf)
1015 struct ISAMB_block *p = pp->block[pp->level];
1019 while (p->offset == p->size)
1022 while (p->offset == p->size)
1026 close_block (pp->isamb, pp->block[pp->level]);
1027 pp->block[pp->level] = 0;
1029 p = pp->block[pp->level];
1032 src = p->bytes + p->offset;
1034 decode_ptr (&src, &item_len);
1036 decode_ptr (&src, &pos);
1038 p->offset = src - (char*) p->bytes;
1044 pp->block[pp->level] = p = open_block (pp->isamb, pos);
1046 pp->total_size += p->size;
1053 src = p->bytes + p->offset;
1054 decode_ptr (&src, &pos);
1055 p->offset = src - (char*) p->bytes;
1059 assert (p->offset < p->size);
1061 src = p->bytes + p->offset;
1062 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
1064 p->offset = src - (char*) p->bytes;
1065 key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1");
1070 int isamb_pp_read (ISAMB_PP pp, void *buf)
1072 return isamb_pp_forward(pp,buf,0);
1076 int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
1080 * while at end of node
1081 * climb higher. If out, return 0
1082 * while not on a leaf (and not at its end)
1091 * The upper nodes consist of a sequence of nodenumbers and keys
1092 * When opening a block, the first node number is read in, and
1093 * offset points to the first key, which is the upper limit of keys
1094 * in the node just read.
1098 struct ISAMB_block *p = pp->block[pp->level];
1105 logf(LOG_DEBUG,"isamb_pp_forward starting [%p] p=%d",pp,p->pos);
1106 key_logdump_txt(LOG_DEBUG, untilbuf," until");
1107 key_logdump_txt(LOG_DEBUG, buf, " buf");
1110 while ( p->offset == p->size)
1111 { /* end of this block - climb higher */
1112 logf(LOG_DEBUG,"isamb_pp_forward climbing from l=%d",
1116 logf(LOG_DEBUG,"isamb_pp_forward returning 0 at root");
1117 return 0; /* at end of the root, nothing left */
1119 close_block(pp->isamb, pp->block[pp->level]);
1120 pp->block[pp->level]=0;
1122 p=pp->block[pp->level];
1123 logf(LOG_DEBUG,"isamb_pp_forward climbed to node %d off=%d",
1126 /* skip the child we have handled */
1127 if (p->offset != p->size)
1129 src = p->bytes + p->offset;
1130 decode_ptr(&src, &item_len);
1131 key_logdump_txt(LOG_DEBUG, src, " isamb_pp_forward climb skipping old key");
1133 decode_ptr(&src,&pos);
1134 p->offset = src - (char*) p->bytes;
1135 break; /* even if this puts us at the end of the block, we need to */
1136 /* descend to the last pos. UGLY coding, clean up some */
1142 src = p->bytes + p->offset;
1143 if (p->offset == p->size)
1144 cmp=-2 ; /* descend to the last node, as we have no value to cmp */
1147 decode_ptr(&src, &item_len);
1148 logf(LOG_DEBUG,"isamb_pp_forward (B) on a high node. ofs=%d sz=%d nxtpos=%d ",
1149 p->offset,p->size,pos);
1150 key_logdump(LOG_DEBUG, src);
1152 cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
1156 decode_ptr(&src,&nxtpos);
1160 logf(LOG_DEBUG,"isambb_pp_forward descending l=%d p=%d ",
1163 p = open_block(pp->isamb,pos);
1164 pp->block[pp->level] = p ;
1165 pp->total_size += p->size;
1166 (pp->accessed_nodes[pp->maxlevel - pp->level])++;
1169 { /* block starts with a pos */
1170 src = p->bytes + p->offset;
1171 decode_ptr(&src,&pos);
1172 p->offset=src-(char*) p->bytes;
1173 logf(LOG_DEBUG,"isamb_pp_forward: block %d starts with %d",
1176 } /* descend to the node */
1178 { /* skip the node */
1179 p->offset = src - (char*) p->bytes;
1181 (pp->skipped_nodes[pp->maxlevel - pp->level -1])++;
1183 "isamb_pp_forward: skipping block on level %d, noting on %d (%d)",
1184 pp->level, pp->maxlevel - pp->level-1 ,
1185 pp->skipped_nodes[pp->maxlevel - pp->level-1 ]);
1186 /* 0 is always leafs, 1 is one level above leafs etc, no
1187 * matter how high tree */
1189 } /* not on a leaf */
1192 src = p->bytes + p->offset;
1194 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
1196 p->offset = src - (char*) p->bytes;
1198 cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
1201 logf(LOG_DEBUG,"isamb_pp_forward on a leaf. cmp=%d",
1203 key_logdump(LOG_DEBUG, buf);
1207 key_logdump_txt(LOG_DEBUG, buf,
1208 "isamb_pp_forward returning 1");
1210 key_logdump_txt(LOG_DEBUG, buf,
1211 "isamb_pp_read returning 1 (fwd)");
1212 pp->returned_numbers++;
1216 pp->skipped_numbers++;
1222 int isamb_pp_num (ISAMB_PP pp)