2 * Copyright (c) 1995-1996, Index Data.
3 * See the file LICENSE for details.
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.1 1996-10-29 13:40:48 adam
20 ISAMC_M isc_getmethod (void)
22 static struct ISAMC_filecat_s def_cat[] = {
24 { 512, 490, 100, 20 },
25 { 4096, 3950, 1000, 20 },
26 {32768, 32000, 10000, 0 },
29 ISAMC_M m = xmalloc (sizeof(*m));
36 m->compare_item = NULL;
44 ISAMC isc_open (const char *name, int writeflag, ISAMC_M method)
47 ISAMC_filecat filecat;
51 is = xmalloc (sizeof(*is));
53 is->method = xmalloc (sizeof(*is->method));
54 memcpy (is->method, method, sizeof(*method));
55 filecat = is->method->filecat;
58 /* determine number of block categories */
59 if (is->method->debug)
60 logf (LOG_LOG, "isc: bsize ifill mfill mblocks");
61 for (i = 0; filecat[i].bsize; i++)
63 if (is->method->debug)
64 logf (LOG_LOG, "isc:%6d %6d %6d %6d",
65 filecat[i].bsize, filecat[i].ifill,
66 filecat[i].mfill, filecat[i].mblocks);
67 if (max_buf_size < filecat[i].mblocks * filecat[i].bsize)
68 max_buf_size = filecat[i].mblocks * filecat[i].bsize;
72 /* max_buf_size is the larget buffer to be used during merge */
73 max_buf_size = (1 + max_buf_size / filecat[i].bsize) * filecat[i].bsize;
74 if (is->method->debug)
75 logf (LOG_LOG, "isc: max_buf_size %d", max_buf_size);
77 assert (is->no_files > 0);
78 is->files = xmalloc (sizeof(*is->files)*i);
79 is->r_buf = xmalloc (max_buf_size+128);
80 for (i = 0; i<is->no_files; i++)
84 sprintf (fname, "%s%c", name, i+'A');
85 is->files[i].bf = bf_open (fname, is->method->filecat[i].bsize,
87 is->files[i].head_is_dirty = 0;
88 if (!bf_read (is->files[i].bf, 0, 0, sizeof(ISAMC_head),
91 is->files[i].head.lastblock = 1;
92 is->files[i].head.freelist = 0;
98 int isc_close (ISAMC is)
102 for (i = 0; i<is->no_files; i++)
105 if (is->files[i].head_is_dirty)
106 bf_write (is->files[i].bf, 0, 0, sizeof(ISAMC_head),
108 bf_close (is->files[i].bf);
116 void isc_catpos (ISAMC_P ipos, int *cat, int *pos)
122 int isc_read_block (ISAMC is, int cat, int pos, char *dst)
124 if (is->method->debug > 1)
125 logf (LOG_LOG, "isc: read_block %d %d", cat, pos);
126 return bf_read (is->files[cat].bf, pos, 0, 0, dst);
129 int isc_write_block (ISAMC is, int cat, int pos, char *src)
131 if (is->method->debug > 1)
132 logf (LOG_LOG, "isc: write_block %d %d", cat, pos);
133 return bf_write (is->files[cat].bf, pos, 0, 0, src);
136 int isc_write_dblock (ISAMC is, int cat, int pos, char *src,
137 int nextpos, int offset)
139 int xoffset = offset + 2*sizeof(int);
140 if (is->method->debug > 2)
141 logf (LOG_LOG, "isc: write_dblock. offset=%d nextpos=%d",
143 memcpy (src - sizeof(int)*2, &nextpos, sizeof(int));
144 memcpy (src - sizeof(int), &xoffset, sizeof(int));
145 return isc_write_block (is, cat, pos, src - sizeof(int)*2);
148 int isc_alloc_block (ISAMC is, int cat)
151 char buf[sizeof(int)];
153 is->files[cat].head_is_dirty = 1;
154 if ((block = is->files[cat].head.freelist))
156 bf_read (is->files[cat].bf, block, 0, sizeof(int), buf);
157 memcpy (&is->files[cat].head.freelist, buf, sizeof(int));
160 block = (is->files[cat].head.lastblock)++;
161 if (is->method->debug > 2)
162 logf (LOG_LOG, "isc: alloc_block in cat %d -> %d", cat, block);
166 void isc_release_block (ISAMC is, int cat, int pos)
168 char buf[sizeof(int)];
170 is->files[cat].head_is_dirty = 1;
171 memcpy (buf, &is->files[cat].head.freelist, sizeof(int));
172 is->files[cat].head.freelist = pos;
173 bf_write (is->files[cat].bf, pos, 0, sizeof(int), buf);
176 static void isc_flush_blocks (ISAMC is, int *r_ptr, int r_ptri, char *r_buf,
177 int *nextpos, int *firstpos, int cat, int last)
181 for (i = 1; i<r_ptri; i++)
187 pos = isc_alloc_block (is, cat);
190 if (last && i == r_ptri-1)
193 *nextpos = isc_alloc_block (is, cat);
194 isc_write_dblock (is, cat, pos, r_buf + r_ptr[i-1], *nextpos,
195 r_ptr[i] - r_ptr[i-1]);
200 ISAMC_P isc_merge_first (ISAMC is, ISAMC_I data)
202 char i_item[128], *i_item_ptr;
203 int i_more, i_mode, i;
208 char r_item_buf[128];
212 void *r_clientData = (*is->method->code_start)(ISAMC_ENCODE);
213 char *r_buf = is->r_buf + ISAMC_BLOCK_OFFSET;
215 /* read first item from i */
217 i_more = (*data->read_item)(data->clientData, &i_item_ptr, &i_mode);
222 char *r_item = r_item_buf;
224 memcpy (r_item, i_item, i_item_ptr - i_item);
226 if (r_item) /* insert resulting item? */
228 char *r_out_ptr = r_buf + r_offset;
230 int border = r_ptr[r_ptri-1] + is->method->filecat[cat].ifill
233 (*is->method->code_item)(ISAMC_ENCODE, r_clientData,
234 &r_out_ptr, &r_item);
235 new_offset = r_out_ptr - r_buf;
237 if (border >= r_offset && border < new_offset)
239 /* Initial fill of current block category reached...
242 r_ptr[r_ptri++] = r_offset;
243 if (cat == is->max_cat)
245 /* We are dealing with block of max size. Block(s)
246 will be flushed. Note: the block(s) are surely not
249 if (is->method->debug > 1)
250 logf (LOG_LOG, "isc: flush %d sections", r_ptri-1);
251 isc_flush_blocks (is, r_ptr, r_ptri, r_buf,
252 &nextpos, &firstpos, cat, 0);
255 memcpy (r_buf, r_buf + r_offset, new_offset - r_offset);
256 new_offset = (new_offset - r_offset);
259 r_offset = new_offset;
260 if (cat < is->max_cat &&
261 r_ptri>is->method->filecat[cat].mblocks)
263 /* Max number blocks in current category reached ->
264 must switch to next category (with larger block size)
268 /* r_ptr[0] = r_ptr[0] = 0 true anyway.. */
269 for (i = 2; i < r_ptri; i++)
271 border = is->method->filecat[cat].ifill -
272 ISAMC_BLOCK_OFFSET + r_ptr[j-1];
273 if (r_ptr[i] > border && r_ptr[i-1] <= border)
274 r_ptr[j++] = r_ptr[i-1];
280 i_more = (*data->read_item)(data->clientData, &i_item_ptr, &i_mode);
282 r_ptr[r_ptri++] = r_offset;
283 /* flush rest of block(s) in r_buf */
284 if (is->method->debug > 1)
285 logf (LOG_LOG, "isc: flush rest, %d sections", r_ptri-1);
286 isc_flush_blocks (is, r_ptr, r_ptri, r_buf, &nextpos, &firstpos, cat, 1);
287 (*is->method->code_stop)(ISAMC_ENCODE, r_clientData);
288 return cat + firstpos * 8;
291 ISAMC_P isc_merge (ISAMC is, ISAMC_P ipos, ISAMC_I data)
294 return isc_merge_first (is, data);
299 ISAMC_P isc_merge (ISAMC is, ISAMC_P ipos, ISAMC_I data)
302 char f_item[128], *f_item_ptr;
307 char i_item[128], *i_item_ptr;
308 int i_more, insertMode;
310 char r_item_buf[128];
311 int r_offset = ISAMC_BLOCK_OFFSET;
316 void *r_clientData = (*is->method->code_start)();
318 /* rewind and read first item from file */
319 pp = isc_position (is, ipos);
321 f_more = isc_read_item (pp, &f_item_ptr);
324 /* read first item from i */
326 i_more = (*data->read_item)(data->clientData, &i_item_ptr, &insertMode);
328 while (f_more || i_more)
331 char *r_item = r_item_buf;
338 cmp = (*is->method->compare_item)(i_item, f_item);
339 if (cmp == 0) /* insert i=f */
347 memcpy (r_item, f_item, f_item_ptr - f_item);
351 i_more = (*data->read_item)(data->clientData, &i_item_ptr,
355 f_more = isc_read_item (pp, &f_item_ptr);
357 else if (cmp > 0) /* insert f */
359 memcpy (r_item, f_item, f_item_ptr - f_item);
362 f_more = isc_read_item (pp, &f_item_ptr);
366 if (!insertMode) /* delete item which isn't there? */
368 logf (LOG_FATAL, "Inconsistent register");
371 memcpy (r_item, i_item, i_item_ptr - i_item);
375 i_more = (*data->read_item)(data->clientData, &i_item_ptr,
378 /* check for end of input block condition */
380 if (r_item) /* insert resulting item? */
382 char *r_out_ptr = is->r_buf + r_offset;
384 int border = is->method->filecat[cat].initsize - r_start;
386 (*is->method->code_item)(r_clientData, &r_out_ptr, &r_item);
387 new_offset = r_out_ptr - is->r_buf;
389 if (border >= r_offset && border < r_newoffset)
391 r_ptr[r_ptri++] = r_offset;
392 if (!is->method->filecat[cat].mblocks)
394 assert (r_ptri == 1);
395 /* dump block from 0 -> r_offset in max cat */
397 r_offset = ISAMC_BLOCK_OFFSET;
400 r_offset = new_offset;
402 if (r_ptri && r_ptri == is->method->filecat[cat].mblocks)
406 /* dump previous blocks in chain */
410 for (i = 1; i<r_ptr; i++)
412 if (r_ptr[i] > is->method->filecat[cat].ifill &&
413 r_ptr[i-1] <= is->method->filecat[cat].ifill)
414 r_ptr[j++] = r_ptr[i-1];
419 (*is->method->code_stop)(r_clientData);
424 void isc_pp_close (ISAMC_PP pp)
428 (*is->method->code_stop)(ISAMC_DECODE, pp->decodeClientData);
433 ISAMC_PP isc_pp_open (ISAMC is, ISAMC_P ipos)
435 ISAMC_PP pp = xmalloc (sizeof(*pp));
438 isc_catpos (ipos, &pp->cat, &pp->next);
440 src = pp->buf = xmalloc (is->method->filecat[pp->cat].bsize);
446 pp->decodeClientData = (*is->method->code_start)(ISAMC_DECODE);
450 /* returns 1 if item could be read; 0 otherwise */
451 int isc_read_key (ISAMC_PP pp, void *buf)
453 return isc_read_item (pp, (char **) &buf);
456 /* returns 1 if item could be read; 0 otherwise */
457 int isc_read_item (ISAMC_PP pp, char **dst)
460 char *src = pp->buf + pp->offset;
462 if (pp->offset >= pp->size)
468 isc_read_block (is, pp->cat, pp->pos, src);
470 memcpy (&pp->next, src, sizeof(pp->next));
471 src += sizeof(pp->next);
472 memcpy (&pp->size, src, sizeof(pp->size));
473 src += sizeof(pp->size);
474 /* assume block is non-empty */
475 assert (pp->next != pp->pos);
477 (*is->method->code_item)(ISAMC_DECODE, pp->decodeClientData, dst, &src);
478 pp->offset = src - pp->buf;
482 int isc_read_islast (ISAMC_PP pp)
484 return pp->offset >= pp->size;
487 int isc_numkeys (ISAMC_PP pp)