-
-/* 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...
-*/
-
-
-static void isamh_reduceblock(ISAMH is, ISAMH_PP pp, int numKeys)
-{
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_reduce: block p=%d c=%d o=%d nk=%d ",
- pp->pos, pp->cat, pp->offset, numKeys);
- if (pp->pos != 0)
- return; /* already allocated in some size */
- while ( ( pp->cat > 0 ) &&
- ( pp->offset < is->method->filecat[pp->cat-1].bsize) &&
- ( numKeys < is->method->filecat[pp->cat-1].mblocks) )
- pp->cat--;
- pp->pos = isamh_alloc_block(is,pp->cat) ;
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_reduced block p=%d to c=%d o=%d nk=%d bs=%d",
- pp->pos, pp->cat, pp->offset, numKeys,
- is->method->filecat[pp->cat].bsize);
-} /* reduceblock */
-
-
-ISAMC_P isamh_append (ISAMH is, ISAMH_P ipos, ISAMH_I data)
-{
-
- ISAMH_PP pp; /* always the last pp in the chain */
- ISAMH_PP firstpp; /* always the first one in the chain, may ==pp */
- ISAMH_PP prevpp; /* the one that points to pp, may be null or ==firstpp */
- /* needed to postpone the writing of its next field until */
- /* pp itself has been categorized */
- char i_item[128];
- char *i_item_ptr;
- int i_more=1, i_mode;
-
- char codebuffer[128];
- char *codeptr;
- char *bufptr;
- int codelen;
-
- void *r_clientData; /* encode client data */
- int newblock;
- int newcat;
- int maxkeys;
- int maxsize;
- int retval;
- int maxcat;
-
- pp = firstpp = isamh_pp_open (is, ipos);
- prevpp =0; /* only used when new blocks allocated */
-
- assert (*is->method->code_reset);
-
- maxcat=0; /* find the largest block size for default allocation */
- for ( newcat=0; is->method->filecat[newcat].mblocks > 0; newcat++)
- if ( is->method->filecat[newcat].bsize >
- is->method->filecat[maxcat].bsize)
- maxcat = newcat;
-
- if ( 0==ipos)
- { /* new block */
- pp->cat=maxcat; /* start large... */
- pp->pos = 0; /* not allocated yet */
- pp->size= pp->offset = ISAMH_BLOCK_OFFSET_1 ;
- pp->buf=xrealloc(pp->buf,is->method->filecat[maxcat].bsize);
- r_clientData = (*is->method->code_start)(ISAMH_ENCODE);
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_append: starting with new block");
- }
- else
- { /* existing block */
- if (isamh_block(firstpp->lastblock) == firstpp->pos)
- /*!!! TODO: BUG: Compare whole addresses !!! (later) */
- { /* 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 = maxcat; /* start with a large block again */
- 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 );
-
- newblock = 0;
- pp->next = 0;
-
- /* Four possibilities: */
- if (prevpp!=0)
- { /* 1: we have a prevpp that can go on the disk */
- /* reduce pp, set next ptr, and store block */
- /* set pp up as new last block, and remember the just */
- /* filled as (pp) the new prev */
- assert(pp!=firstpp);
- isamh_reduceblock(is,pp,firstpp->numKeys);
- prevpp->next=isamh_addr(pp->pos,pp->cat);
- isamh_buildlaterblock(prevpp);
- isamh_write_block(is,prevpp->cat,prevpp->pos,prevpp->buf);
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_append N1: Wrote prevpp (%d:%d) -> %d:%d",
- prevpp->pos, prevpp->cat, pp->pos, pp->cat);
- isamh_pp_close(prevpp); /* it's done its job */
- prevpp = pp;
- pp=isamh_pp_open(is,isamh_addr(0,maxcat)); /* start a large one */
- pp->size=pp->offset=ISAMH_BLOCK_OFFSET_N ;
- pp->next=0;
- pp->lastblock=0;
- }
- else if ( (firstpp!=pp) && (firstpp->next != 0))
- { /* 2: we are working at end of list, but have no prevpp */
- /* some block (already on disk) points to pp */
- /* set the newly filled block as prev, don't save yet */
- /* allocate new pp */
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_append N2: set up a new prevpp (%d:%d)",
- pp->pos, pp->cat);
- prevpp = pp;
- pp=isamh_pp_open(is,isamh_addr(0,maxcat)); /* start a large one */
- pp->size=pp->offset=ISAMH_BLOCK_OFFSET_N ;
- pp->next=0;
- pp->lastblock=0;
- }
- else if ( (firstpp!=pp) && (firstpp->next==0))
- { /* 3: we have earlier allocated pp as the second block */
- /* reduce it to get its address. Set first->next to it */
- /* move it to prevpp, and create a new pp */
- isamh_reduceblock(is,pp,firstpp->numKeys);
- firstpp->next=isamh_addr(pp->pos,pp->cat);
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_append N3: set up a new firstpp->next (%d:%d)",
- pp->pos, pp->cat);
- prevpp=pp;
- pp=isamh_pp_open(is,isamh_addr(0,maxcat)); /* start a large one */
- pp->size=pp->offset=ISAMH_BLOCK_OFFSET_N ;
- pp->next=0;
- pp->lastblock=0;
- }
- else
- { /* 4: firstpp itself has got full. */
- /* allocate a new pp for it, store nothing */
- assert(firstpp==pp);
- assert(firstpp->next==0);
- if (pp->is->method->debug > 2)
- logf(LOG_LOG,"isamh_append N4: allocated new pp for full first (%d:%d)",
- firstpp->pos, firstpp->cat);
- pp=isamh_pp_open(is,isamh_addr(0,maxcat)); /* start a large one */
- pp->size=pp->offset=ISAMH_BLOCK_OFFSET_N ;
- pp->next=0;
- pp->lastblock=0;
- }
-
- maxsize = is->method->filecat[pp->cat].bsize;
- 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 c=%d p=%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 */
-
- isamh_reduceblock(is,pp,firstpp->numKeys);
- /* may be the same as firstpp! */
-
- if (prevpp)
- { /* Write the prev block we have been holding off */
- assert(prevpp->pos);
- prevpp->next = isamh_addr(pp->pos, pp->cat);
- isamh_buildlaterblock(prevpp);
- isamh_write_block(is,prevpp->cat,prevpp->pos,prevpp->buf);
- if (firstpp->next==0) /* can happen if extending many blocks */
- firstpp->next=isamh_addr(prevpp->pos,prevpp->cat);
- isamh_pp_close(prevpp);
- }
- /* Write the last (partial) block, if needed. */
- if (pp!=firstpp)
- {
- pp->next=0; /* just to be sure */
- if (firstpp->next==0)
- firstpp->next=isamh_addr(pp->pos,pp->cat);
- 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_reduceblock(is,firstpp,firstpp->numKeys);
- 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 */
-
-