-struct trunc_info {
- int *ptr;
- int *indx;
- char **heap;
- int heapnum;
- int (*cmp)(const void *p1, const void *p2);
- int keysize;
- char *swapbuf;
- char *tmpbuf;
- char *buf;
-};
-
-static void heap_swap (struct trunc_info *ti, int i1, int i2)
-{
- int swap;
-
- swap = ti->ptr[i1];
- ti->ptr[i1] = ti->ptr[i2];
- ti->ptr[i2] = swap;
-}
-
-static void heap_delete (struct trunc_info *ti)
-{
- int cur = 1, child = 2;
-
- heap_swap (ti, 1, ti->heapnum--);
- while (child <= ti->heapnum) {
- if (child < ti->heapnum &&
- (*ti->cmp)(ti->heap[ti->ptr[child]],
- ti->heap[ti->ptr[1+child]]) > 0)
- child++;
- if ((*ti->cmp)(ti->heap[ti->ptr[cur]],
- ti->heap[ti->ptr[child]]) > 0)
- {
- heap_swap (ti, cur, child);
- cur = child;
- child = 2*cur;
- }
- else
- break;
- }
-}
-
-static void heap_insert (struct trunc_info *ti, const char *buf, int indx)
-{
- int cur, parent;
-
- cur = ++(ti->heapnum);
- memcpy (ti->heap[ti->ptr[cur]], buf, ti->keysize);
- ti->indx[ti->ptr[cur]] = indx;
- parent = cur/2;
- while (parent && (*ti->cmp)(ti->heap[ti->ptr[parent]],
- ti->heap[ti->ptr[cur]]) > 0)
- {
- heap_swap (ti, cur, parent);
- cur = parent;
- parent = cur/2;
- }
-}
-
-static
-struct trunc_info *heap_init (int size, int key_size,
- int (*cmp)(const void *p1, const void *p2))
-{
- struct trunc_info *ti = xmalloc (sizeof(*ti));
- int i;
-
- ++size;
- ti->heapnum = 0;
- ti->keysize = key_size;
- ti->cmp = cmp;
- ti->indx = xmalloc (size * sizeof(*ti->indx));
- ti->heap = xmalloc (size * sizeof(*ti->heap));
- ti->ptr = xmalloc (size * sizeof(*ti->ptr));
- ti->swapbuf = xmalloc (ti->keysize);
- ti->tmpbuf = xmalloc (ti->keysize);
- ti->buf = xmalloc (size * ti->keysize);
- for (i = size; --i >= 0; )
- {
- ti->ptr[i] = i;
- ti->heap[i] = ti->buf + ti->keysize * i;
- }
- return ti;
-}
-
-static void heap_close (struct trunc_info *ti)
-{
- xfree (ti->ptr);
- xfree (ti->indx);
- xfree (ti->heap);
- xfree (ti->swapbuf);
- xfree (ti->tmpbuf);
- xfree (ti);
-}
-
-static RSET rset_trunc_r (ISAM isam, ISAM_P *isam_p, int from, int to,
- int merge_chunk)
-{
- RSET result;
- RSFD result_rsfd;
- rset_temp_parms parms;
-
- parms.key_size = sizeof(struct it_key);
- result = rset_create (rset_kind_temp, &parms);
- result_rsfd = rset_open (result, RSETF_WRITE|RSETF_SORT_SYSNO);
-
- if (to - from > merge_chunk)
- {
- RSFD *rsfd;
- RSET *rset;
- int i, i_add = (to-from)/merge_chunk + 1;
- struct trunc_info *ti;
- int rscur = 0;
- int rsmax = (to-from)/i_add + 1;
-
- rset = xmalloc (sizeof(*rset) * rsmax);
- rsfd = xmalloc (sizeof(*rsfd) * rsmax);
-
- for (i = from; i < to; i += i_add)
- {
- if (i_add <= to - i)
- rset[rscur] = rset_trunc_r (isam, isam_p, i, i+i_add,
- merge_chunk);
- else
- rset[rscur] = rset_trunc_r (isam, isam_p, i, to,
- merge_chunk);
- rscur++;
- }
- ti = heap_init (rscur, sizeof(struct it_key), key_compare);
- for (i = rscur; --i >= 0; )
- {
- rsfd[i] = rset_open (rset[i], RSETF_READ|RSETF_SORT_SYSNO);
- if (rset_read (rset[i], rsfd[i], ti->tmpbuf))
- heap_insert (ti, ti->tmpbuf, i);
- else
- {
- rset_close (rset[i], rsfd[i]);
- rset_delete (rset[i]);
- }
- }
- while (ti->heapnum)
- {
- int n = ti->indx[ti->ptr[1]];
-
- rset_write (result, result_rsfd, ti->heap[ti->ptr[1]]);
-
- while (1)
- {
- if (!rset_read (rset[n], rsfd[n], ti->tmpbuf))
- {
- heap_delete (ti);
- rset_close (rset[n], rsfd[n]);
- rset_delete (rset[n]);
- break;
- }
- if ((*ti->cmp)(ti->tmpbuf, ti->heap[ti->ptr[1]]) > 1)
- {
- heap_delete (ti);
- heap_insert (ti, ti->tmpbuf, n);
- break;
- }
- }
- }
- xfree (rset);
- xfree (rsfd);
- heap_close (ti);
- }
- else
- {
- ISPT *ispt;
- int i;
- struct trunc_info *ti;
-
- ispt = xmalloc (sizeof(*ispt) * (to-from));
-
- ti = heap_init (to-from, sizeof(struct it_key),
- key_compare);
- for (i = to-from; --i >= 0; )
- {
- ispt[i] = is_position (isam, isam_p[from+i]);
- if (is_readkey (ispt[i], ti->tmpbuf))
- heap_insert (ti, ti->tmpbuf, i);
- else
- is_pt_free (ispt[i]);
- }
- while (ti->heapnum)
- {
- int n = ti->indx[ti->ptr[1]];
-
- rset_write (result, result_rsfd, ti->heap[ti->ptr[1]]);
-#if 0
-/* section that preserve all keys */
- heap_delete (ti);
- if (is_readkey (ispt[n], ti->tmpbuf))
- heap_insert (ti, ti->tmpbuf, n);
- else
- is_pt_free (ispt[n]);
-#else
-/* section that preserve all keys with unique sysnos */
- while (1)
- {
- if (!is_readkey (ispt[n], ti->tmpbuf))
- {
- heap_delete (ti);
- is_pt_free (ispt[n]);
- break;
- }
- if ((*ti->cmp)(ti->tmpbuf, ti->heap[ti->ptr[1]]) > 1)
- {
- heap_delete (ti);
- heap_insert (ti, ti->tmpbuf, n);
- break;
- }
- }
-#endif
- }
- heap_close (ti);
- xfree (ispt);
- }
- rset_close (result, result_rsfd);
- return result;
-}
-
-static int isam_trunc_cmp (const void *p1, const void *p2)
-{
- ISAM_P i1 = *(ISAM_P*) p1;
- ISAM_P i2 = *(ISAM_P*) p2;
- int d;
-
- d = is_type (i1) - is_type (i2);
- if (d)
- return d;
- return is_block (i1) - is_block (i2);
-}
-
-static RSET rset_trunc (ISAM isam, ISAM_P *isam_p, int no)
-{
- assert (isam);
- qsort (isam_p, no, sizeof(*isam_p), isam_trunc_cmp);
- return rset_trunc_r (isam, isam_p, 0, no, 100);
-}
-