2 * Copyright (c) 2000-2002, Index Data.
3 * See the file LICENSE for details.
5 * $Id: isamb.c,v 1.12 2002-04-30 08:28:37 adam Exp $
7 #include <yaz/xmalloc.h>
19 #define ISAMB_DATA_OFFSET 3
21 #define DST_ITEM_MAX 256
23 /* approx 2*4 K + max size of item */
24 #define DST_BUF_SIZE 8448
30 struct ISAMB_head head;
37 struct ISAMB_file *file;
50 void *decodeClientData;
59 struct ISAMB_block **block;
62 void encode_ptr (char **dst, int pos)
64 memcpy (*dst, &pos, sizeof(pos));
65 (*dst) += sizeof(pos);
68 void decode_ptr (char **src, int *pos)
70 memcpy (pos, *src, sizeof(*pos));
71 (*src) += sizeof(*pos);
74 ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M method)
76 ISAMB isamb = xmalloc (sizeof(*isamb));
80 isamb->method = (ISAMC_M) xmalloc (sizeof(*method));
81 memcpy (isamb->method, method, sizeof(*method));
84 isamb->file = xmalloc (sizeof(*isamb->file) * isamb->no_cat);
85 for (i = 0; i<isamb->no_cat; i++)
87 char fname[DST_BUF_SIZE];
88 isamb->file[i].head.first_block = 1;
89 isamb->file[i].head.last_block = 1;
90 isamb->file[i].head.block_size = b_size;
91 isamb->file[i].head.block_max = b_size - ISAMB_DATA_OFFSET;
93 isamb->file[i].head_dirty = 0;
94 sprintf (fname, "%s-%d", name, i);
96 bf_open (bfs, fname, isamb->file[i].head.block_size, writeflag);
98 bf_read (isamb->file[i].bf, 0, 0, sizeof(struct ISAMB_head),
99 &isamb->file[i].head);
104 void isamb_close (ISAMB isamb)
107 for (i = 0; i<isamb->no_cat; i++)
109 if (isamb->file[i].head_dirty)
110 bf_write (isamb->file[i].bf, 0, 0,
111 sizeof(struct ISAMB_head), &isamb->file[i].head);
114 xfree (isamb->method);
118 struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
121 struct ISAMB_block *p;
124 p = xmalloc (sizeof(*p));
127 p->buf = xmalloc (b->file[cat].head.block_size);
128 bf_read (b->file[cat].bf, pos/4, 0, 0, p->buf);
129 p->bytes = p->buf + ISAMB_DATA_OFFSET;
131 p->size = p->buf[1] + 256 * p->buf[2] - ISAMB_DATA_OFFSET;
134 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
138 struct ISAMB_block *new_block (ISAMB b, int leaf, int cat)
140 struct ISAMB_block *p;
143 p = xmalloc (sizeof(*p));
144 block_no = b->file[cat].head.last_block++;
146 p->pos = block_no * 4 + cat;
148 b->file[cat].head_dirty = 1;
149 p->buf = xmalloc (b->file[cat].head.block_size);
150 memset (p->buf, 0, b->file[cat].head.block_size);
151 p->bytes = p->buf + ISAMB_DATA_OFFSET;
156 p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
160 struct ISAMB_block *new_leaf (ISAMB b, int cat)
162 return new_block (b, 1, cat);
166 struct ISAMB_block *new_int (ISAMB b, int cat)
168 return new_block (b, 0, cat);
171 void close_block (ISAMB b, struct ISAMB_block *p)
177 int size = p->size + ISAMB_DATA_OFFSET;
179 p->buf[1] = size & 255;
180 p->buf[2] = size >> 8;
181 bf_write (b->file[p->cat].bf, p->pos/4, 0, 0, p->buf);
183 (*b->method->code_stop)(ISAMC_DECODE, p->decodeClientData);
188 int insert_sub (ISAMB b, struct ISAMB_block **p,
191 struct ISAMB_block **sp,
192 void *sub_item, int *sub_size,
195 int insert_int (ISAMB b, struct ISAMB_block *p, void *lookahead_item,
196 ISAMC_I stream, struct ISAMB_block **sp,
197 void *split_item, int *split_size)
199 char *startp = p->bytes;
201 char *endp = p->bytes + p->size;
203 struct ISAMB_block *sub_p1 = 0, *sub_p2 = 0;
204 char sub_item[DST_ITEM_MAX];
210 decode_ptr (&src, &pos);
215 decode_ptr (&src, &item_len);
216 d = (*b->method->compare_item)(src, lookahead_item);
219 sub_p1 = open_block (b, pos);
221 more = insert_sub (b, &sub_p1, lookahead_item, stream, &sub_p2,
222 sub_item, &sub_size, src);
226 decode_ptr (&src, &pos);
230 sub_p1 = open_block (b, pos);
232 more = insert_sub (b, &sub_p1, lookahead_item, stream, &sub_p2,
233 sub_item, &sub_size, 0);
237 /* there was a split - must insert pointer in this one */
238 char dst_buf[DST_BUF_SIZE];
241 assert (sub_size < 30 && sub_size > 1);
243 memcpy (dst, startp, src - startp);
247 encode_ptr (&dst, sub_size); /* sub length and item */
248 memcpy (dst, sub_item, sub_size);
251 encode_ptr (&dst, sub_p2->pos); /* pos */
253 if (endp - src) /* remaining data */
255 memcpy (dst, src, endp - src);
258 p->size = dst - dst_buf;
259 if (p->size <= b->file[p->cat].head.block_max)
261 memcpy (startp, dst_buf, dst - dst_buf);
270 half = src + b->file[p->cat].head.block_size/2;
271 decode_ptr (&src, &pos);
274 decode_ptr (&src, split_size);
276 decode_ptr (&src, &pos);
278 p_new_size = src - dst_buf;
279 memcpy (p->bytes, dst_buf, p_new_size);
281 decode_ptr (&src, split_size);
282 memcpy (split_item, src, *split_size);
285 *sp = new_int (b, p->cat);
286 (*sp)->size = endp - src;
287 memcpy ((*sp)->bytes, src, (*sp)->size);
289 p->size = p_new_size;
292 close_block (b, sub_p2);
294 close_block (b, sub_p1);
299 int insert_leaf (ISAMB b, struct ISAMB_block **sp1, void *lookahead_item,
300 ISAMC_I stream, struct ISAMB_block **sp2,
301 void *sub_item, int *sub_size,
304 struct ISAMB_block *p = *sp1;
305 char *src = 0, *endp = 0;
306 char dst_buf[DST_BUF_SIZE], *dst = dst_buf;
308 void *c1 = (*b->method->code_start)(ISAMC_DECODE);
309 void *c2 = (*b->method->code_start)(ISAMC_ENCODE);
311 int quater = b->file[b->no_cat-1].head.block_max / 4;
312 char *cut = dst_buf + quater * 2;
313 char *maxp = dst_buf + b->file[b->no_cat-1].head.block_max;
316 char cut_item_buf[DST_ITEM_MAX];
317 int cut_item_size = 0;
321 char file_item_buf[DST_ITEM_MAX];
322 char *file_item = file_item_buf;
325 endp = p->bytes + p->size;
326 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
331 char *lookahead_next;
336 d = (*b->method->compare_item)(file_item_buf, lookahead_item);
339 dst_item = lookahead_item;
341 dst_item = file_item_buf;
342 if (!half1 && dst > cut)
344 char *dst_item_0 = dst_item;
345 half1 = dst; /* candidate for splitting */
347 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
349 cut_item_size = dst_item - dst_item_0;
350 memcpy (cut_item_buf, dst_item_0, cut_item_size);
355 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
365 lookahead_next = lookahead_item;
366 if (!(*stream->read_item)(stream->clientData,
374 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
376 yaz_log (LOG_LOG, "max_item 1");
385 lookahead_next = lookahead_item;
386 if (!(*stream->read_item)(stream->clientData,
387 &lookahead_next, &lookahead_mode))
394 file_item = file_item_buf;
395 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
401 file_item = file_item_buf;
402 (*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
406 maxp = dst_buf + b->file[b->no_cat-1].head.block_max + quater;
407 while (lookahead_item)
410 char *dst_item = lookahead_item;
414 (*b->method->compare_item)(max_item, lookahead_item) <= 0)
416 yaz_log (LOG_LOG, "max_item 2");
419 if (!half1 && dst > cut)
421 char *dst_item_0 = dst_item;
422 half1 = dst; /* candidate for splitting */
424 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
426 cut_item_size = dst_item - dst_item_0;
427 memcpy (cut_item_buf, dst_item_0, cut_item_size);
432 (*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
441 dst_item = lookahead_item;
442 if (!(*stream->read_item)(stream->clientData, &dst_item,
449 new_size = dst - dst_buf;
450 if (p && p->cat != b->no_cat-1 &&
451 new_size > b->file[p->cat].head.block_max)
453 /* non-btree block will be removed */
455 /* delete it too!! */
456 p = 0; /* make a new one anyway */
459 { /* must create a new one */
461 for (i = 0; i < b->no_cat; i++)
462 if (new_size <= b->file[i].head.block_max)
468 if (new_size > b->file[p->cat].head.block_max)
471 char *cut_item = cut_item_buf;
477 p->size = half1 - dst_buf;
478 memcpy (p->bytes, dst_buf, half1 - dst_buf);
481 *sp2 = new_leaf (b, p->cat);
483 (*b->method->code_reset)(c2);
485 first_dst = (*sp2)->bytes;
487 (*b->method->code_item)(ISAMC_ENCODE, c2, &first_dst, &cut_item);
489 memcpy (first_dst, half2, dst - half2);
491 (*sp2)->size = (first_dst - (*sp2)->bytes) + (dst - half2);
494 memcpy (sub_item, cut_item_buf, cut_item_size);
495 *sub_size = cut_item_size;
499 memcpy (p->bytes, dst_buf, dst - dst_buf);
502 (*b->method->code_stop)(ISAMC_DECODE, c1);
503 (*b->method->code_stop)(ISAMC_ENCODE, c2);
508 int insert_sub (ISAMB b, struct ISAMB_block **p, void *new_item,
510 struct ISAMB_block **sp,
511 void *sub_item, int *sub_size,
514 if (!*p || (*p)->leaf)
515 return insert_leaf (b, p, new_item, stream, sp, sub_item, sub_size,
518 return insert_int (b, *p, new_item, stream, sp, sub_item, sub_size);
521 int isamb_merge (ISAMB b, ISAMC_P pos, ISAMC_I stream)
523 char item_buf[DST_ITEM_MAX];
529 more = (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
532 struct ISAMB_block *p = 0, *sp = 0;
533 char sub_item[DST_ITEM_MAX];
537 p = open_block (b, pos);
538 more = insert_sub (b, &p, item_buf, stream, &sp,
539 sub_item, &sub_size, 0);
541 { /* increase level of tree by one */
542 struct ISAMB_block *p2 = new_int (b, p->cat);
543 char *dst = p2->bytes + p2->size;
545 encode_ptr (&dst, p->pos);
546 assert (sub_size < 20);
547 encode_ptr (&dst, sub_size);
548 memcpy (dst, sub_item, sub_size);
550 encode_ptr (&dst, sp->pos);
552 p2->size = dst - p2->bytes;
553 pos = p2->pos; /* return new super page */
558 pos = p->pos; /* return current one (again) */
564 ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
566 ISAMB_PP pp = xmalloc (sizeof(*pp));
569 pp->block = xmalloc (10 * sizeof(*pp->block));
577 struct ISAMB_block *p = open_block (isamb, pos);
578 char *src = p->bytes + p->offset;
579 pp->block[pp->level] = p;
581 pp->total_size += p->size;
587 decode_ptr (&src, &pos);
588 p->offset = src - p->bytes;
591 pp->block[pp->level+1] = 0;
597 ISAMB_PP isamb_pp_open (ISAMB isamb, ISAMB_P pos)
599 return isamb_pp_open_x (isamb, pos, 0);
602 void isamb_pp_close_x (ISAMB_PP pp, int *size, int *blocks)
608 *size = pp->total_size;
610 *blocks = pp->no_blocks;
611 for (i = 0; i <= pp->level; i++)
612 close_block (pp->isamb, pp->block[i]);
617 int isamb_block_info (ISAMB isamb, int cat)
619 if (cat >= 0 && cat < isamb->no_cat)
620 return isamb->file[cat].head.block_size;
624 void isamb_pp_close (ISAMB_PP pp)
626 return isamb_pp_close_x (pp, 0, 0);
629 int isamb_pp_read (ISAMB_PP pp, void *buf)
633 struct ISAMB_block *p = pp->block[pp->level];
637 while (p->offset == p->size)
640 while (p->offset == p->size)
644 close_block (pp->isamb, pp->block[pp->level]);
645 pp->block[pp->level] = 0;
647 p = pp->block[pp->level];
648 assert (!p->leaf); /* must be int */
650 src = p->bytes + p->offset;
652 decode_ptr (&src, &item_len);
654 decode_ptr (&src, &pos);
656 p->offset = src - (char*) p->bytes;
662 pp->block[pp->level] = p = open_block (pp->isamb, pos);
664 pp->total_size += p->size;
667 if (p->leaf) /* leaf */
671 src = p->bytes + p->offset;
672 decode_ptr (&src, &pos);
673 p->offset = src - (char*) p->bytes;
677 assert (p->offset < p->size);
679 src = p->bytes + p->offset;
680 (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
682 p->offset = src - (char*) p->bytes;
686 int isamb_pp_num (ISAMB_PP pp)