+static char *hexdump(unsigned char *p, int len, char *buff) {
+ static char localbuff[128];
+ char bytebuff[8];
+ if (!buff) buff=localbuff;
+ *buff='\0';
+ while (len--) {
+ sprintf(bytebuff,"%02x",*p);
+ p++;
+ strcat(buff,bytebuff);
+ if (len) strcat(buff,",");
+ }
+ return buff;
+}
+
+
+/* isamh - heikki's append-only isam
+ * Idea: When allocating a new block, allocate memory for a very large block
+ * (maximal blocksize). When done, see if you can shrink it to some
+ * smaller size. First-time indexing will go in optimal blocks, and
+ * following small additions will go to the end of the last of the
+ * maximal ones. Only later, when new blocks need to be allocated, it
+ * may make sense to reserve some extra space...
+*/
+
+ISAMC_P isamh_append (ISAMH is, ISAMH_P ipos, ISAMH_I data)
+{
+
+ ISAMH_PP pp;
+
+ char i_item[128];
+ char *i_item_ptr;
+ int i_more=1, i_mode;
+
+ char codebuffer[128];
+ char *codeptr;
+ char *bufptr;
+ int codelen;
+
+ ISAMH_PP firstpp;
+ void *r_clientData; /* encode client data */
+ int newblock;
+ int newcat;
+ int maxkeys;
+ int maxsize;
+ int retval;
+
+ pp = firstpp = isamh_pp_open (is, ipos);
+ assert (*is->method->code_reset);
+
+ if ( 0==ipos)
+ { /* new block */
+ pp->cat=0; /* start small... */
+ pp->pos = isamh_alloc_block(is,pp->cat);
+ pp->size= pp->offset = ISAMH_BLOCK_OFFSET_1 ;
+ r_clientData = (*is->method->code_start)(ISAMH_ENCODE);
+ if (pp->is->method->debug > 2)
+ logf(LOG_LOG,"isamh_append: starting with new block %d",pp->pos);
+ }
+ else
+ { /* existing block */
+ if (isamh_block(firstpp->lastblock) == firstpp->pos)
+ { /* only one block, we have it already */
+ pp->offset=ISAMH_BLOCK_OFFSET_1;
+ if (pp->is->method->debug > 2)
+ logf(LOG_LOG,"isamh_append: starting with one block %d",pp->pos);
+ }
+ else
+ {
+ if (pp->is->method->debug > 2)
+ logf(LOG_LOG,"isamh_append: starting with multiple blocks %d>%d>%d",
+ firstpp->pos,isamh_block(firstpp->next),isamh_block(firstpp->lastblock));
+ pp=isamh_pp_open(is,firstpp->lastblock);
+ /* dirty, but this can also read a N-block. Just clear extra values*/
+ pp->lastblock=0;
+ pp->offset=ISAMH_BLOCK_OFFSET_N;
+ } /* get last */
+ r_clientData = (*is->method->code_start)(ISAMH_ENCODE);
+ if (pp->is->method->debug > 3)
+ logf(LOG_LOG,"isamh_append: scanning to end of block %d %d->%d",
+ pp->pos, pp->offset, pp->size);
+ codeptr=codebuffer;
+ while (pp->offset<pp->size) {
+ codeptr=codebuffer;
+ bufptr=pp->buf + pp->offset;
+ (*is->method->code_item)(ISAMH_DECODE, r_clientData, &codeptr, &bufptr);
+ codelen = bufptr - (pp->buf+pp->offset) ;
+ if (pp->is->method->debug > 3)
+ logf(LOG_LOG,"isamh_append: dec at %d %d/%d:%s",
+ pp->offset, codelen, codeptr-codebuffer,
+ hexdump(codebuffer,codeptr-codebuffer,0) );
+ pp->offset += codelen;
+ }
+ } /* existing block */
+
+
+ i_item_ptr = i_item;
+ i_more = (*data->read_item)(data->clientData,&i_item_ptr,&i_mode);
+ if (pp->is->method->debug > 3)
+ logf(LOG_LOG,"isamh_append 1: m=%d l=%d %s",
+ i_mode, i_item_ptr-i_item, hexdump(i_item,i_item_ptr-i_item,0));
+
+ maxsize = is->method->filecat[pp->cat].bsize;
+
+ while(i_more) {
+ if (i_mode)
+ { /* insert key, ignore all delete keys time being... */
+ codeptr = codebuffer;
+ i_item_ptr=i_item;
+ (*is->method->code_item)(ISAMH_ENCODE, r_clientData, &codeptr, &i_item_ptr);
+ codelen = codeptr-codebuffer;
+
+ assert( (codelen < 128) && (codelen>0));
+
+ if (pp->is->method->debug > 3)
+ logf(LOG_LOG,"isamh_append: coded into %d:%s (nk=%d)",
+ codelen,hexdump(codebuffer,codelen,0),firstpp->numKeys);
+
+ if ( pp->offset + codelen > maxsize )
+ { /* oops, block full, do something */
+ newcat = pp->cat;
+ maxkeys = is->method->filecat[pp->cat].mblocks; /* max keys */
+ if (pp->is->method->debug > 2)
+ logf(LOG_LOG,"isamh_append: need new block: %d > %d (k:%d/%d)",
+ pp->offset + codelen, maxsize, firstpp->numKeys,maxkeys );
+ if ( (maxkeys>0) && (firstpp->numKeys > maxkeys) )
+ { /* time to increase block size */
+ newcat++;
+ maxsize = is->method->filecat[newcat].bsize;
+ pp->buf=xrealloc(pp->buf,maxsize);
+ if (pp->is->method->debug > 2)
+ logf(LOG_LOG,"isamh_append: increased to cat %d ",newcat);
+ }
+
+ newblock = isamh_alloc_block(is,newcat);
+ pp->next = isamh_addr(newblock,newcat);
+ if (firstpp!=pp)
+ { /* not first block, write to disk already now */
+ isamh_buildlaterblock(pp);
+ isamh_write_block(is,pp->cat,pp->pos,pp->buf);
+ }
+ else
+ { /* we had only one block, allocate a second buffer */
+ pp = isamh_pp_open(is,0);
+ }
+ pp->cat = newcat;
+ pp->pos = newblock;
+
+ pp->size=pp->offset=ISAMH_BLOCK_OFFSET_N ;
+ pp->next=0;
+ pp->lastblock=0;
+ if (pp->is->method->debug > 2)
+ logf(LOG_LOG,"isamh_append: got a new block %d:%d",pp->cat,pp->pos);
+
+ /* reset the encoding, and code again */
+ (*is->method->code_reset)(r_clientData);
+ codeptr = codebuffer;
+ i_item_ptr=i_item;
+ (*is->method->code_item)(ISAMH_ENCODE, r_clientData, &codeptr, &i_item_ptr);
+ codelen = codeptr-codebuffer;
+ if (pp->is->method->debug > 3)
+ logf(LOG_LOG,"isamh_append: coded again %d:%s (nk=%d)",
+ codelen,hexdump(codebuffer,codelen,0),firstpp->numKeys);
+
+ } /* block full */
+
+ /* ok, now we can write it */
+ memcpy(&(pp->buf[pp->offset]), codebuffer, codelen);
+ pp->offset += codelen;
+ pp->size += codelen;
+ firstpp->numKeys++;
+ } /* not a delete */
+
+ /* try to read the next element */
+ i_item_ptr = i_item;
+ i_more = (*data->read_item)(data->clientData,&i_item_ptr,&i_mode);
+ if (pp->is->method->debug > 3)
+ logf(LOG_LOG,"isamh_append 2: m=%d l=%d %s",
+ i_mode, i_item_ptr-i_item, hexdump(i_item,i_item_ptr-i_item,0));
+
+ } /* while */
+
+ /* Write the last (partial) block, if needed. */
+ if (pp!=firstpp)
+ {
+ pp->next=0; /* just to be sure */
+ isamh_buildlaterblock(pp);
+ isamh_write_block(is,pp->cat,pp->pos,pp->buf);
+ }
+
+ /* update first block and write it */
+ firstpp->lastblock = isamh_addr(pp->pos,pp->cat);
+ isamh_buildfirstblock(firstpp);
+ isamh_write_block(is,firstpp->cat,firstpp->pos,firstpp->buf);
+
+ /* release the second block, if we allocated one */
+ if ( firstpp != pp )
+ isamh_pp_close(pp);
+
+ /* get return value (before it disappears at close! */
+ retval = isamh_addr(firstpp->pos,firstpp->cat);
+
+ isamh_pp_close(firstpp);
+
+ return retval;
+
+} /* isamh_append */
+
+
+/*
+ * $Log: merge.c,v $
+ * Revision 1.18 1999-07-13 15:24:50 heikki
+ * Removed the one-block append, it had a serious flaw.
+ *
+ * Revision 1.16 1999/07/08 14:23:27 heikki
+ * Fixed a bug in isamh_pp_read and cleaned up a bit
+ *
+ * Revision 1.15 1999/07/07 09:36:04 heikki
+ * Fixed an assertion in isamh
+ *
+ * Revision 1.13 1999/07/06 09:37:05 heikki
+ * Working on isamh - not ready yet.
+ *
+ * Revision 1.12 1999/06/30 15:03:55 heikki
+ * first take on isamh, the append-only isam structure
+ *
+ * Revision 1.11 1999/05/26 07:49:14 adam
+ * C++ compilation.
+ *
+ * Revision 1.10 1998/03/19 12:22:09 adam
+ * Minor change.
+ *
+ * Revision 1.9 1998/03/19 10:04:38 adam
+ * Minor changes.
+ *
+ * Revision 1.8 1998/03/18 09:23:55 adam
+ * Blocks are stored in chunks on free list - up to factor 2 in speed.
+ * Fixed bug that could occur in block category rearrangemen.
+ *
+ * Revision 1.7 1998/03/11 11:18:18 adam
+ * Changed the isc_merge to take into account the mfill (minimum-fill).
+ *
+ * Revision 1.6 1998/03/06 13:54:03 adam
+ * Fixed two nasty bugs in isc_merge.
+ *
+ * Revision 1.5 1997/02/12 20:42:43 adam
+ * Bug fix: during isc_merge operations, some pages weren't marked dirty
+ * even though they should be. At this point the merge operation marks
+ * a page dirty if the previous page changed at all. A better approach is
+ * to mark it dirty if the last key written changed in previous page.
+ *
+ * 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
+ * New element, max_blocks_mem, that control how many blocks of max size
+ * to store in memory during isc_merge.
+ * Function isc_merge now ignores delete/update of identical keys and
+ * the proper blocks are then non-dirty and not written in flush_blocks.
+ *
+ * Revision 1.1 1996/11/01 08:59:15 adam
+ * First version of isc_merge that supports update/delete.
+ *
+ */
+
+