2 * Copyright (c) 1995-1999, Index Data.
3 * See the file LICENSE for details.
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.3 1999-05-20 12:57:18 adam
8 * Implemented TCL filter. Updated recctrl system.
10 * Revision 1.2 1999/05/15 14:35:48 adam
13 * Revision 1.1 1999/05/12 13:08:06 adam
14 * First version of ISAMS.
30 typedef unsigned ISAMS_BLOCK_SIZE;
48 void *decodeClientData;
53 ISAMS_M isams_getmethod (void)
55 ISAMS_M m = xmalloc (sizeof(*m));
61 m->compare_item = NULL;
69 ISAMS isams_open (BFiles bfs, const char *name, int writeflag,
72 ISAMS is = xmalloc (sizeof(*is));
74 is->method = xmalloc (sizeof(*is->method));
75 memcpy (is->method, method, sizeof(*method));
76 is->block_size = is->method->block_size;
77 is->debug = is->method->debug;
79 is->bf = bf_open (bfs, name, is->block_size, writeflag);
81 if (!bf_read (is->bf, 0, 0, sizeof(ISAMS_head), &is->head))
83 is->head.last_block = 1;
84 is->head.last_offset = 0;
86 memcpy (&is->head_old, &is->head, sizeof(is->head));
87 is->merge_buf = xmalloc(2*is->block_size);
88 memset(is->merge_buf, 0, 2*is->block_size);
92 int isams_close (ISAMS is)
94 if (memcmp(&is->head, &is->head_old, sizeof(is->head)))
96 if (is->head.last_offset)
97 bf_write(is->bf, is->head.last_block, 0, is->head.last_offset,
99 bf_write (is->bf, 0, 0, sizeof(is->head), &is->head);
102 xfree (is->merge_buf);
108 ISAMS_P isams_merge (ISAMS is, ISAMS_I data)
110 char i_item[128], *i_item_ptr;
113 int first_block = is->head.last_block;
114 int first_offset = is->head.last_offset;
117 r_clientData = (*is->method->code_start)(ISAMC_ENCODE);
119 is->head.last_offset += sizeof(int);
120 if (is->head.last_offset > is->block_size)
123 logf (LOG_LOG, "first_block=%d", first_block);
124 bf_write(is->bf, is->head.last_block, 0, 0, is->merge_buf);
125 (is->head.last_block)++;
126 is->head.last_offset -= is->block_size;
127 memcpy (is->merge_buf, is->merge_buf + is->block_size,
128 is->head.last_offset);
133 i_more = (*data->read_item)(data->clientData, &i_item_ptr, &i_mode);
140 char *r_out_ptr = is->merge_buf + is->head.last_offset;
143 (*is->method->code_item)(ISAMC_ENCODE, r_clientData,
144 &r_out_ptr, &i_item_ptr);
145 is->head.last_offset = r_out_ptr - is->merge_buf;
146 if (is->head.last_offset > is->block_size)
148 bf_write(is->bf, is->head.last_block, 0, 0, is->merge_buf);
149 (is->head.last_block)++;
150 is->head.last_offset -= is->block_size;
151 memcpy (is->merge_buf, is->merge_buf + is->block_size,
152 is->head.last_offset);
157 (*is->method->code_stop)(ISAMC_ENCODE, r_clientData);
158 if (first_block == is->head.last_block)
159 memcpy(is->merge_buf + first_offset, &count, sizeof(int));
160 else if (first_block == is->head.last_block-1)
162 int gap = first_offset + sizeof(int) - is->block_size;
163 assert (gap <= (int) sizeof(int));
166 if (gap < sizeof(int))
167 bf_write(is->bf, first_block, first_offset, sizeof(int)-gap,
169 memcpy (is->merge_buf, ((char*)&count)+(sizeof(int)-gap), gap);
172 bf_write(is->bf, first_block, first_offset, sizeof(int), &count);
176 bf_write(is->bf, first_block, first_offset, sizeof(int), &count);
178 return first_block * is->block_size + first_offset;
181 ISAMS_PP isams_pp_open (ISAMS is, ISAMS_P pos)
183 ISAMS_PP pp = xmalloc (sizeof(*pp));
186 logf (LOG_LOG, "isams: isams_pp_open pos=%ld", (long) pos);
188 pp->decodeClientData = (*is->method->code_start)(ISAMC_DECODE);
191 pp->buf = xmalloc(is->block_size*2);
192 pp->block_no = pos/is->block_size;
193 pp->block_offset = pos - pp->block_no * is->block_size;
194 logf (LOG_LOG, "isams: isams_pp_open off=%d no=%d",
195 pp->block_offset, pp->block_no);
198 bf_read (is->bf, pp->block_no, 0, 0, pp->buf);
199 bf_read (is->bf, pp->block_no+1, 0, 0, pp->buf + is->block_size);
200 memcpy(&pp->numKeys, pp->buf + pp->block_offset, sizeof(int));
201 logf (LOG_LOG, "isams: isams_pp_open numKeys=%d", pp->numKeys);
202 pp->block_offset += sizeof(int);
207 void isams_pp_close (ISAMS_PP pp)
209 (*pp->is->method->code_stop)(ISAMC_DECODE, pp->decodeClientData);
214 int isams_pp_num (ISAMS_PP pp)
219 int isams_pp_read (ISAMS_PP pp, void *buf)
221 return isams_read_item (pp, (char **) &buf);
224 int isams_read_item (ISAMS_PP pp, char **dst)
227 if (pp->numRead >= pp->numKeys)
230 if (pp->block_offset > pp->is->block_size)
232 pp->block_offset -= pp->is->block_size;
234 memcpy (pp->buf, pp->buf + pp->is->block_size, pp->is->block_size);
235 bf_read (pp->is->bf, pp->block_no+1, 0, 0,
236 pp->buf + pp->is->block_size);
238 src = pp->buf + pp->block_offset;
239 (*pp->is->method->code_item)(ISAMC_DECODE, pp->decodeClientData,
241 pp->block_offset = src - pp->buf;