#include <assert.h>
#include <string.h>
#include <stdio.h>
-
#include <log.h>
#include "isamc-p.h"
#include "isamh-p.h"
return cat + firstpos * 8;
}
-ISAMC_P isamh_append (ISAMH is, ISAMH_P ipos, ISAMH_I data)
-{
+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;
+}
- char i_item[128], *i_item_ptr;
- int i_more, i_mode, i;
- ISAMH_PP pp;
- char f_item[128], *f_item_ptr;
- int f_more;
- int last_dirty = 0;
- int debug = is->method->debug;
-
- struct isc_merge_block mb[200];
+/* 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...
+*/
- int firstpos = 0;
- int cat = 0;
- char r_item_buf[128]; /* temporary result output */
- char *r_buf; /* block with resulting data */
- 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)(ISAMH_ENCODE);
- r_buf = is->merge_buf + 128;
+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 */
- pp = isamh_pp_open (is, ipos);
- /* read first item from file. make sure f_more indicates no boundary */
- f_item_ptr = f_item;
- f_more = isamh_read_item (pp, &f_item_ptr);
- if (f_more > 0)
- f_more = 1;
- cat = pp->cat;
- if (debug > 1)
- logf (LOG_LOG, "isc: isamh_append begin %d %d", cat, pp->pos);
+ISAMC_P isamh_append (ISAMH is, ISAMH_P ipos, ISAMH_I data)
+{
- /* read first item from i */
- i_item_ptr = i_item;
- i_more = (*data->read_item)(data->clientData, &i_item_ptr, &i_mode);
+ 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;
- mb[ptr].block = pp->pos; /* is zero if no block on disk */
- mb[ptr].dirty = 0;
- mb[ptr].offset = 0;
+ char codebuffer[128];
+ char *codeptr;
+ char *bufptr;
+ int codelen;
- border = is->method->filecat[cat].bsize;
- /* border = get_border (is, mb, ptr, cat, firstpos); */
- while (i_more || f_more)
- {
- char *r_item = r_item_buf;
- int cmp;
+ 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 */
- if (f_more > 1)
- {
- /* block to block boundary in the original file. */
- f_more = 1;
- if (cat == pp->cat)
- {
- /* the resulting output is of the same category as the
- the original
- */
- if (r_offset <= mb[ptr].offset +is->method->filecat[cat].mfill)
- {
- /* the resulting output block is too small/empty. Delete
- the original (if any)
- */
- if (debug > 3)
- logf (LOG_LOG, "isc: release A");
- if (mb[ptr].block)
- isamh_release_block (is, pp->cat, mb[ptr].block);
- mb[ptr].block = pp->pos;
- if (!mb[ptr].dirty)
- mb[ptr].dirty = 1;
- if (ptr > 0)
- mb[ptr-1].dirty = 1;
- }
- else
- {
- /* indicate new boundary based on the original file */
- mb[++ptr].block = pp->pos;
- mb[ptr].dirty = last_dirty;
- mb[ptr].offset = r_offset;
- if (debug > 3)
- logf (LOG_LOG, "isc: bound ptr=%d,offset=%d",
- ptr, r_offset);
- if (cat==is->max_cat && ptr >= is->method->max_blocks_mem)
- {
- /* We are dealing with block(s) of max size. Block(s)
- except 1 will be flushed.
- */
- if (debug > 2)
- logf (LOG_LOG, "isc: flush A %d sections", ptr);
- flush_blocks ((ISAMC)is, mb, ptr-1, r_buf, &firstpos, cat,
- 0, &pp->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;
+
+ 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));
- 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;
- }
- }
+ 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;
}
- /*border = get_border (is, mb, ptr, cat, firstpos);*/
- border = is->method->filecat[cat].bsize;
- }
- last_dirty = 0;
- if (!f_more)
- cmp = -1;
- else if (!i_more)
- cmp = 1;
- else
- cmp = (*is->method->compare_item)(i_item, f_item);
- if (cmp == 0) /* insert i=f */
- {
- if (!i_mode) /* delete item? */
- {
- /* move i */
- i_item_ptr = i_item;
- i_more = (*data->read_item)(data->clientData, &i_item_ptr,
- &i_mode);
- /* is next input item the same as current except
- for the delete flag? */
- cmp = (*is->method->compare_item)(i_item, f_item);
- if (!cmp && i_mode) /* delete/insert nop? */
- {
- /* yes! insert as if it was an insert only */
- memcpy (r_item, i_item, i_item_ptr - i_item);
- i_item_ptr = i_item;
- i_more = (*data->read_item)(data->clientData, &i_item_ptr,
- &i_mode);
- }
- else
- {
- /* no! delete the item */
- r_item = NULL;
- last_dirty = 1;
- mb[ptr].dirty = 2;
- }
+ 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
- {
- memcpy (r_item, f_item, f_item_ptr - f_item);
-
- /* move i */
- i_item_ptr = i_item;
- i_more = (*data->read_item)(data->clientData, &i_item_ptr,
- &i_mode);
+ 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;
}
- /* move f */
- f_item_ptr = f_item;
- f_more = isamh_read_item (pp, &f_item_ptr);
- }
- else if (cmp > 0) /* insert f */
- {
- memcpy (r_item, f_item, f_item_ptr - f_item);
- /* move f */
- f_item_ptr = f_item;
- f_more = isamh_read_item (pp, &f_item_ptr);
- }
- else /* insert i */
- {
- if (!i_mode) /* delete item which isn't there? */
- {
- logf (LOG_FATAL, "Inconsistent register at offset %d",
- r_offset);
- abort ();
- }
- memcpy (r_item, i_item, i_item_ptr - i_item);
- mb[ptr].dirty = 2;
- last_dirty = 1;
- /* move i */
- i_item_ptr = i_item;
- i_more = (*data->read_item)(data->clientData, &i_item_ptr,
- &i_mode);
- }
- if (r_item) /* insert resulting item? */
- {
- char *r_out_ptr = r_buf + r_offset;
- int new_offset;
-
- (*is->method->code_item)(ISAMH_ENCODE, r_clientData,
- &r_out_ptr, &r_item);
- new_offset = r_out_ptr - r_buf;
-
- numKeys++;
-
- if (border < new_offset && border >= r_offset)
- {
- if (debug > 2)
- logf (LOG_LOG, "isc: border %d %d", ptr, border);
- /* Max size of current block category reached ...
- make new virtual block entry */
- mb[++ptr].block = 0;
- mb[ptr].dirty = 1;
- mb[ptr].offset = r_offset;
- if (cat == is->max_cat && ptr >= is->method->max_blocks_mem)
- {
- /* We are dealing with block(s) of max size. Block(s)
- except one will be flushed. Note: the block(s) are
- surely not the last one(s).
- */
- if (debug > 2)
- logf (LOG_LOG, "isc: flush B %d sections", ptr-1);
- flush_blocks ((ISAMC)is, mb, ptr-1, r_buf, &firstpos, cat,
- 0, &pp->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[0].dirty;
- mb[1].offset = mb[ptr].offset - mb[ptr-1].offset;
- memcpy (r_buf + mb[1].offset, r_buf + r_offset,
- new_offset - r_offset);
- new_offset = (new_offset - r_offset) + mb[1].offset;
- ptr = 1;
- }
- border = is->method->filecat[cat].bsize;
- /* get_border (is, mb, ptr, cat, firstpos); */
+ 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;
}
- r_offset = new_offset;
- }
- if (cat < is->max_cat && ptr >= is->method->filecat[cat].mblocks)
- {
- /* Max number blocks in current category reached ->
- must switch to next category (with larger block size)
- */
- int j = 0;
- (is->files[cat].no_remap)++;
- /* delete all original block(s) read so far */
- for (i = 0; i < ptr; i++)
- if (mb[i].block)
- isamh_release_block (is, pp->cat, mb[i].block);
- /* also delete all block to be read in the future */
- pp->deleteFlag = 1;
-
- /* remap block offsets */
- assert (mb[j].offset == 0);
- cat++;
- mb[j].dirty = 1;
- mb[j].block = 0;
- mb[ptr].offset = r_offset;
- for (i = 1; i < ptr; i++)
- {
- int border = is->method->filecat[cat].ifill -
- ISAMH_BLOCK_OFFSET_1 + mb[j].offset;
- if (debug > 3)
- logf (LOG_LOG, "isc: remap %d border=%d", i, border);
- if (mb[i+1].offset > border && mb[i].offset <= border)
- {
- if (debug > 3)
- logf (LOG_LOG, "isc: to %d %d", j, mb[i].offset);
- mb[++j].dirty = 1;
- mb[j].block = 0;
- mb[j].offset = mb[i].offset;
- }
- }
- if (debug > 2)
- logf (LOG_LOG, "isc: remap from %d to %d sections to cat %d",
- ptr, j, cat);
- ptr = j;
- border = is->method->filecat[cat].bsize;
- /*border = get_border (is, mb, ptr, cat, firstpos);*/
- if (debug > 3)
- logf (LOG_LOG, "isc: border=%d r_offset=%d", border, r_offset);
- }
- }
- if (mb[ptr].offset < r_offset)
- { /* make the final boundary offset */
- mb[++ptr].dirty = 1;
- mb[ptr].block = 0;
- mb[ptr].offset = r_offset;
- }
- else
- { /* empty output. Release last block if any */
- if (cat == pp->cat && mb[ptr].block)
- {
- if (debug > 3)
- logf (LOG_LOG, "isc: release C");
- isamh_release_block (is, pp->cat, mb[ptr].block);
- mb[ptr].block = 0;
- if (ptr > 0)
- mb[ptr-1].dirty = 1;
- }
+ 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);
}
-
- if (debug > 2)
- logf (LOG_LOG, "isc: flush C, %d sections", ptr);
-
- if (firstpos)
+ /* Write the last (partial) block, if needed. */
+ if (pp!=firstpp)
{
- /* we have to patch initial block with num keys if that
- has changed */
- if (numKeys != isamh_pp_num (pp))
- {
- if (debug > 2)
- logf (LOG_LOG, "isc: patch num keys firstpos=%d num=%d",
- firstpos, numKeys);
- bf_write (is->files[cat].bf, firstpos, ISAMH_BLOCK_OFFSET_N,
- sizeof(numKeys), &numKeys);
- }
+ 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);
}
- 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 != isamh_pp_num (pp))
- mb[0].dirty = 1;
- }
- /* flush rest of block(s) in r_buf */
- flush_blocks ((ISAMC)is, mb, ptr, r_buf, &firstpos, cat, 1, &numKeys);
+
+ /* 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);
- (*is->method->code_stop)(ISAMH_ENCODE, r_clientData);
- if (!firstpos)
- cat = 0;
- if (debug > 1)
- logf (LOG_LOG, "isc: isamh_append return %d %d", cat, firstpos);
- isamh_pp_close (pp);
- return cat + firstpos * 8;
-}
+ isamh_pp_close(firstpp);
+
+ return retval;
+
+} /* isamh_append */
/*
* $Log: merge.c,v $
- * Revision 1.12 1999-06-30 15:03:55 heikki
+ * Revision 1.19 1999-07-14 12:12:07 heikki
+ * Large-block isam-h (may not work too well... Abandoning for isam-d)
+ *
+ * Revision 1.17 1999/07/13 14:22:17 heikki
+ * Better allocation strategy in isamh_merge
+ *
+ * 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