* Sebastian Hammer, Adam Dickmeiss
*
* $Log: merge.c,v $
- * Revision 1.3 1996-11-04 14:08:59 adam
+ * Revision 1.4 1996-11-08 11:15:31 adam
+ * Number of keys in chain are stored in first block and the function
+ * to retrieve this information, isc_pp_num is implemented.
+ *
+ * Revision 1.3 1996/11/04 14:08:59 adam
* Optimized free block usage.
*
* Revision 1.2 1996/11/01 13:36:46 adam
};
static void flush_blocks (ISAMC is, struct isc_merge_block *mb, int ptr,
- char *r_buf, int *firstpos, int cat, int last)
+ char *r_buf, int *firstpos, int cat, int last,
+ int *numkeys)
{
int i;
for (i = 0; i<ptr; i++)
{
+ unsigned short ssize;
+ char *src;
+
/* skip rest if not dirty */
if (!mb[i].dirty)
{
if (!mb[i].block)
mb[i].block = isc_alloc_block (is, cat);
- if (!*firstpos)
- *firstpos = mb[i].block;
/* consider next block pointer */
if (last && i == ptr-1)
mb[i+1].block = isc_alloc_block (is, cat);
/* write block */
- assert (mb[i+1].offset > mb[i].offset);
- isc_write_dblock (is, cat, mb[i].block, r_buf + mb[i].offset,
- mb[i+1].block, mb[i+1].offset - mb[i].offset);
+ ssize = mb[i+1].offset - mb[i].offset;
+ assert (ssize);
+
+ if (!*firstpos)
+ {
+ *firstpos = mb[i].block;
+ src = r_buf + mb[i].offset - ISAMC_BLOCK_OFFSET_1;
+ ssize += ISAMC_BLOCK_OFFSET_1;
+
+ memcpy (src+sizeof(int)+sizeof(ssize), numkeys,
+ sizeof(*numkeys));
+ if (is->method->debug > 2)
+ logf (LOG_LOG, "isc: flush numk=%d size=%d nextpos=%d",
+ *numkeys, (int) ssize, mb[i+1].block);
+ }
+ else
+ {
+ src = r_buf + mb[i].offset - ISAMC_BLOCK_OFFSET_N;
+ ssize += ISAMC_BLOCK_OFFSET_N;
+ if (is->method->debug > 2)
+ logf (LOG_LOG, "isc: flush size=%d nextpos=%d",
+ (int) ssize, mb[i+1].block);
+ }
+ memcpy (src, &mb[i+1].block, sizeof(int));
+ memcpy (src+sizeof(int), &ssize, sizeof(ssize));
+ isc_write_block (is, cat, mb[i].block, src);
}
}
+static int get_border (ISAMC is, struct isc_merge_block *mb, int ptr,
+ int cat, int firstpos)
+{
+ /* Border set to initial fill or block size depending on
+ whether we are creating a new one or updating and old one.
+ */
+
+ int fill = mb[ptr].block ? is->method->filecat[cat].bsize :
+ is->method->filecat[cat].ifill;
+ int off = (ptr||firstpos) ? ISAMC_BLOCK_OFFSET_N : ISAMC_BLOCK_OFFSET_1;
+
+ assert (ptr < 199);
+
+ return mb[ptr].offset + fill - off;
+}
+
ISAMC_P isc_merge (ISAMC is, ISAMC_P ipos, ISAMC_I data)
{
char f_item[128], *f_item_ptr;
int f_more;
- struct isc_merge_block mb[100];
+ struct isc_merge_block mb[200];
+
int firstpos = 0;
int cat = 0;
char r_item_buf[128]; /* temporary result output */
int r_offset = 0; /* current offset in r_buf */
int ptr = 0; /* pointer */
void *r_clientData; /* encode client data */
+ int border;
+ int numKeys = 0;
r_clientData = (*is->method->code_start)(ISAMC_ENCODE);
- r_buf = is->merge_buf + ISAMC_BLOCK_OFFSET;
+ r_buf = is->merge_buf + 128;
pp = isc_pp_open (is, ipos);
/* read first item from file. make sure f_more indicates no boundary */
mb[ptr].dirty = 0;
mb[ptr].offset = 0;
+ border = get_border (is, mb, ptr, cat, firstpos);
while (i_more || f_more)
{
char *r_item = r_item_buf;
mb[++ptr].block = pp->pos;
mb[ptr].dirty = 0;
mb[ptr].offset = r_offset;
-#if 0
- if (r_item && cat == is->max_cat)
+ if (cat==is->max_cat && ptr >= is->method->max_blocks_mem)
{
/* We are dealing with block(s) of max size. Block(s)
- will be flushed. Note: the block(s) are surely not
- the last one(s).
+ except 1 will be flushed.
*/
if (is->method->debug > 2)
logf (LOG_LOG, "isc: flush A %d sections", ptr);
- flush_blocks (is, mb, ptr-1, r_buf, &firstpos, cat, 0);
- ptr = 0;
- mb[ptr].block = pp->pos;
- mb[ptr].dirty = 0;
- mb[ptr].offset = 0;
+ flush_blocks (is, mb, ptr-1, r_buf, &firstpos, cat,
+ 0, &numKeys);
+
+ mb[0].block = mb[ptr-1].block;
+ mb[0].dirty = mb[ptr-1].dirty;
+ memcpy (r_buf, r_buf + mb[ptr-1].offset,
+ mb[ptr].offset - mb[ptr-1].offset);
+ mb[0].offset = 0;
+
+ mb[1].block = mb[ptr].block;
+ mb[1].dirty = mb[ptr].dirty;
+ mb[1].offset = mb[ptr].offset - mb[ptr-1].offset;
+ ptr = 1;
+ r_offset = mb[ptr].offset;
}
-#endif
}
}
+ border = get_border (is, mb, ptr, cat, firstpos);
}
if (!f_more)
cmp = -1;
{
char *r_out_ptr = r_buf + r_offset;
int new_offset;
- int border;
-
- /* border set to initial fill or block size depending on
- whether we are creating a new one or updating and old one
- */
- if (mb[ptr].block)
- border = mb[ptr].offset + is->method->filecat[cat].bsize
- -ISAMC_BLOCK_OFFSET;
- else
- border = mb[ptr].offset + is->method->filecat[cat].ifill
- -ISAMC_BLOCK_OFFSET;
(*is->method->code_item)(ISAMC_ENCODE, r_clientData,
&r_out_ptr, &r_item);
new_offset = r_out_ptr - r_buf;
+ numKeys++;
+
if (border < new_offset && border >= r_offset)
{
if (is->method->debug > 2)
*/
if (is->method->debug > 2)
logf (LOG_LOG, "isc: flush B %d sections", ptr-1);
- flush_blocks (is, mb, ptr-1, r_buf, &firstpos, cat, 0);
+ flush_blocks (is, mb, ptr-1, r_buf, &firstpos, cat,
+ 0, &numKeys);
mb[0].block = mb[ptr-1].block;
mb[0].dirty = mb[ptr-1].dirty;
new_offset - r_offset);
new_offset = (new_offset - r_offset) + mb[1].offset;
ptr = 1;
- }
+ }
+ border = get_border (is, mb, ptr, cat, firstpos);
}
r_offset = new_offset;
}
for (i = 1; i < ptr; i++)
{
int border = is->method->filecat[cat].ifill -
- ISAMC_BLOCK_OFFSET + mb[j].offset;
+ ISAMC_BLOCK_OFFSET_1 + mb[j].offset;
if (is->method->debug > 3)
logf (LOG_LOG, "isc: remap %d border=%d", i, border);
if (mb[i+1].offset > border && mb[i].offset <= border)
logf (LOG_LOG, "isc: remap from %d to %d sections to cat %d",
ptr, j, cat);
ptr = j;
+ border = get_border (is, mb, ptr, cat, firstpos);
}
}
if (mb[ptr].offset < r_offset)
{ /* make the final boundary offset */
- mb[++ptr].dirty = 1; /* ignored by flush_blocks */
- mb[ptr].block = 0; /* ignored by flush_blocks */
+ mb[++ptr].dirty = 1;
+ mb[ptr].block = 0;
mb[ptr].offset = r_offset;
}
else
if (is->method->debug > 2)
logf (LOG_LOG, "isc: flush C, %d sections", ptr);
+ if (firstpos)
+ {
+ /* we have to patch initial block with num keys if that
+ has changed */
+ if (numKeys != isc_pp_num (pp))
+ {
+ if (is->method->debug > 2)
+ logf (LOG_LOG, "isc: patch num keys firstpos=%d num=%d",
+ firstpos, numKeys);
+ bf_write (is->files[cat].bf, firstpos, ISAMC_BLOCK_OFFSET_N,
+ sizeof(numKeys), &numKeys);
+ }
+ }
+ else if (ptr > 0)
+ { /* we haven't flushed initial block yet and there surely are some
+ blocks to flush. Make first block dirty if numKeys differ */
+ if (numKeys != isc_pp_num (pp))
+ mb[0].dirty = 1;
+ }
/* flush rest of block(s) in r_buf */
- flush_blocks (is, mb, ptr, r_buf, &firstpos, cat, 1);
+ flush_blocks (is, mb, ptr, r_buf, &firstpos, cat, 1, &numKeys);
(*is->method->code_stop)(ISAMC_ENCODE, r_clientData);
if (!firstpos)
cat = 0;
if (is->method->debug > 1)
logf (LOG_LOG, "isc: isc_merge return %d %d", cat, firstpos);
+ isc_pp_close (pp);
return cat + firstpos * 8;
}
projects / idzebra-moved-to-github.git / blobdiff