X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=isamc%2Fmerge-d.c;h=29fc63025d949a5c03bbce2063659f15885855d7;hb=e150e51a7e20a902e9fd2f11f00811f94f67d529;hp=47902e4a437ded4de0bd401eba8889b14dfd1d71;hpb=672c57c13fdaa8e1e7b752671034dc871f613a51;p=idzebra-moved-to-github.git

diff --git a/isamc/merge-d.c b/isamc/merge-d.c
index 47902e4..29fc630 100644
--- a/isamc/merge-d.c
+++ b/isamc/merge-d.c
@@ -3,18 +3,283 @@
  * See the file LICENSE for details.
  * Heikki Levanto
  *
- * merge-d.c: merge routines for isamd
+ * $Id: merge-d.c,v 1.25 1999-11-30 13:48:04 adam Exp $
  *
+ * bugs
+ *  sinleton-bit has to be in the high end, not low, so as not to confuse
+ *  ordinary small numbers, like in the next pointer..
+ *
+ * missing
+ *
+ * optimize
+ *  - study and optimize block sizes (later)
+ *  - find a way to decide the size of an empty diffblock (after merge)
+ *  - On allocating more blocks (in append and merge), check the order of 
+ *    blocks, and if needed, swap them. 
+ *  - Write a routine to save/load indexes into a block, save only as many 
+ *    bytes as needed (size, diff, diffindexes)
+ *
+ *
+ * caveat
+ *  There is a confusion about the block addresses. cat or type is the category,
+ *  pos or block is the block number. pp structures keep these two separate,
+ *  and combine when saving the pp. The next pointer in the pp structure is
+ *  also a combined address, but needs to be combined every time it is needed,
+ *  and separated when the partss are needed... This is done with the isamd_
+ *  _block, _type, and _addr macros. The _addr takes block and type as args,
+ *  in that order. This conflicts with the order these are often mentioned in 
+ *  the debug log calls, and other places, leading to small mistakes here
+ *  and there. 
+ *
+ *  Needs cleaning! The way diff blocks are handled in append and reading is
+ *  quite different, and likely to give maintenance problems.
+ *
+ *  log levels (set isamddebug=x in zebra.cfg (or what ever cfg file you use) )
+ *    0 = no logging. Default
+ *    1 = no logging here. isamd logs overall statistics
+ *    2 = Each call to isamd_append with start address and no more
+ *    3 = Start and type of append, start of merge, and result of append
+ *    4 = Block allocations
+ *    5 = Block-level operations (read/write)
+ *    6 = Details about diff blocks etc.
+ *    7 = Log each record as it passes the system (once)
+ *    8 = Log raw and (de)coded data
+ *    9 = Anything else that may be useful
+ *   .. = Anything needed to hunt a specific bug
+ *  (note that all tests in the code are like debug>3, which means 4 or above!)
+ *
+ * Design for the new and improved isamd
+ * Key points:
+ *  - The first block is only diffs, no straight data
+ *  - Additional blocks are straight data
+ *  - When a diff block gets filled up, a data block is created by
+ *    merging the diffs with the data
+ *
+ * Structure
+ *  - Isamd_pp: buffer for diffs and for data
+ *              keep both pos, type, and combined address
+ *              routine to set the address
+ *  - diffbuf: lengths as short ints, or bytes for small blocks
+ *  - keys are of key_struct, not just a number of bytes.
+ *
+ * Routines
+ *  - isamd_append
+ *    - create_new_block if needed
+ *    - append_diffs
+ *      - load_diffs 
+ *      - get diffend, start encoding
+ *      - while input data
+ *        - encode it
+ *        - if no room, then realloc block in larger size
+ *        - if still no room, merge and exit
+ *        - append in the block
+ *
+ * - merge
+ *   - just as before, except that merges also input data directly
+ *   - writes into new data blocks
+ *       
+ *      
+ * - isamd.c: load firstpp, load datablock
+ *            save firstpp, save datablock
+ * - Readlength, writelength - handling right size of len fields
+ * - isamd_read_main_item: take also a merge input structure, and merge it too
+ * - prefilter: cache two inputs, and check if they cancel.
+ * - single-item optimization
+ * 
+ * questions: Should we realloc firstblocks in a different size as the main
+ * blocks. Makes a sideways seek, which is bound to be slowe. But saves some
+ * update time. Compromise: alloc the first one in the size of the datablock,
+ * but increase if necessary. Large blocks get a large diff, ok. Small ones
+ * may get an extra seek in read, but save merges.
  */
 
+
+#define NEW_ISAM_D 1  /* not yet ready to delete the old one! */
+
 #include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 #include <stdio.h>
-#include <log.h>
+#include <yaz/log.h>
+#include "../index/index.h"
 #include "isamd-p.h"
 
 
+struct ISAMD_DIFF_s {
+  int diffidx;
+  int maxidx;
+  struct it_key key;
+  void *decodeData;
+  int mode;
+  int difftype;  
+};
+
+#define DT_NONE 0 // no diff, marks end of sequence
+#define DT_DIFF 1 // ordinarry diff
+#define DT_MAIN 2 // main data
+#define DT_INPU 3 // input data to be merged
+#define DT_DONE 4 // done with all input here
+
+
+
+/***************************************************************
+ * Input preprocess filter
+ ***************************************************************/
+
+
+#define FILTER_NOTYET -1  /* no data read in yet, to be done */
+
+struct ISAMD_FILTER_s {
+  ISAMD_I data;          /* where the data comes from */
+  ISAMD is;              /* for debug flags */
+  struct it_key k1;      /* the next item to be returned */
+  int           m1;      /* mode for k1 */
+  int           r1;      /* result for read of k1, or NOTYET */
+  struct it_key k2;      /* the one after that */
+  int           m2;
+  int           r2;
+};
+
+typedef struct ISAMD_FILTER_s *FILTER;
+
+
+void filter_fill(FILTER F)
+{
+  while ( (F->r1 == FILTER_NOTYET) || (F->r2 == FILTER_NOTYET) )
+  {
+     if (F->r1==FILTER_NOTYET) 
+     { /* move data forward in the filter */
+        F->k1 = F->k2;
+        F->m1 = F->m2;
+        F->r1 = F->r2;
+        if ( 0 != F->r1 ) /* not eof */
+          F->r2 = FILTER_NOTYET; /* say we want more */
+        if (F->is->method->debug > 9)  
+          logf(LOG_LOG,"filt_fill: shift %d.%d m=%d r=%d",
+             F->k1.sysno, 
+             F->k1.seqno, 
+             F->m1, F->r1);
+     }
+     if (F->r2==FILTER_NOTYET)
+     { /* read new bottom value */
+        char *k_ptr = (char*) &F->k2;
+        F->r2 = (F->data->read_item)(F->data->clientData, &k_ptr, &F->m2); 
+        if (F->is->method->debug > 9)
+          logf(LOG_LOG,"filt_fill: read %d.%d m=%d r=%d",
+             F->k2.sysno, F->k2.seqno, F->m2, F->r2);
+     }  
+     if ( (F->k1.sysno == F->k2.sysno) && 
+          (F->k1.seqno == F->k2.seqno) &&
+          (F->m1 != F->m2) &&
+          (F->r1 >0 ) && (F->r2 >0) )
+     { /* del-ins pair of same key (not eof) , ignore both */
+       if (F->is->method->debug > 9)
+         logf(LOG_LOG,"filt_fill: skipped %d.%d m=%d/%d r=%d/%d",
+            F->k1.sysno, F->k1.seqno, 
+            F->m1,F->m2, F->r1,F->r2);
+       F->r1 = FILTER_NOTYET;
+       F->r2 = FILTER_NOTYET;
+     }
+  } /* while */
+} /* filter_fill */
+
+
+FILTER filter_open( ISAMD is, ISAMD_I data )
+{
+  FILTER F = (FILTER) xmalloc(sizeof(struct ISAMD_FILTER_s));
+  F->is = is;
+  F->data = data;
+  F->k1.sysno=0;
+  F->k1.seqno=0;
+  F->k2=F->k1; 
+  F->m1 = F->m2 = 0;
+  F->r1 = F->r2 = FILTER_NOTYET;
+  filter_fill(F);
+  return F;
+}
+
+static void filter_close (FILTER F)
+{
+  xfree(F);
+}
+
+static int filter_read( FILTER F, 
+                        struct it_key *k,
+                        int *mode)
+{
+  int res;
+  filter_fill(F);
+  if (F->is->method->debug > 9)
+    logf(LOG_LOG,"filt_read: reading %d.%d m=%d r=%d",
+       F->k1.sysno, F->k1.seqno, F->m1, F->r1);
+  res  = F->r1;
+  if(res) 
+  {
+    *k = F->k1;
+    *mode= F->m1;
+  }
+  F->r1 = FILTER_NOTYET;
+  return res;
+}
+
+static int filter_isempty(FILTER F)
+{
+  return ( (0 == F->r1) && (0 == F->r2)) ;
+}
+
+static int filter_only_one(FILTER F)
+{
+  return ( (0 != F->r1) && (0 == F->r2));
+}
+
+
+
+
+/***************************************************************
+ * Singleton encoding
+ ***************************************************************/
+/* When there is only a single item, we don't allocate a block
+ * for it, but code it in the directory entry directly, if it
+ * fits.
+ */
+
+#define DEC_SYSBITS 15
+#define DEC_SEQBITS 15
+#define DEC_MASK(n) ((1<<(n))-1)
+
+#define SINGLETON_BIT (1<<(DEC_SYSBITS+DEC_SEQBITS+1))
+
+int is_singleton(ISAMD_P ipos)
+{
+  return ( ipos != 0 ) && ( ipos & SINGLETON_BIT );
+}
+
+
+int singleton_encode(struct it_key *k)
+/* encodes the key into one int. If it does not fit, returns 0 */
+{
+  if ( (k->sysno & DEC_MASK(DEC_SYSBITS) ) != k->sysno )
+    return 0;  /* no room dor sysno */
+  if ( (k->seqno & DEC_MASK(DEC_SYSBITS) ) != k->seqno )
+    return 0;  /* no room dor sysno */
+  return (k->sysno | (k->seqno << DEC_SYSBITS) ) | SINGLETON_BIT;
+}
+ 
+void singleton_decode (int code, struct it_key *k)
+{
+  assert (code & SINGLETON_BIT);
+  k->sysno = code & DEC_MASK(DEC_SYSBITS);
+  code = code >> DEC_SYSBITS; 
+  k->seqno = code & DEC_MASK(DEC_SEQBITS);
+} 
+ 
+ 
+/***************************************************************
+ * General support routines
+ ***************************************************************/
+
+
+
 static char *hexdump(unsigned char *p, int len, char *buff) {
   static char localbuff[128];
   char bytebuff[8];
@@ -30,20 +295,901 @@ static char *hexdump(unsigned char *p, int len, char *buff) {
 }
 
 
-/* isamd - heikki's append-only isam 
-*/
 
+static void isamd_reduceblock(ISAMD_PP pp)
+/* takes a large block, and reduces its category if possible */
+/* Presumably the first block in an isam-list */
+{
+   if (pp->pos)
+      return; /* existing block, do not touch */
+      /* TODO: Probably we may touch anyway? */
+   if (pp->is->method->debug > 5)  
+     logf(LOG_LOG,"isamd_reduce: start p=%d c=%d sz=%d",
+       pp->pos, pp->cat, pp->size); 
+   while ( ( pp->cat > 0 ) && (!pp->next) && 
+           (pp->offset < pp->is->method->filecat[pp->cat-1].bsize ) )
+      pp->cat--;
+   pp->pos = isamd_alloc_block(pp->is, pp->cat);
+   if (pp->is->method->debug > 5) 
+     logf(LOG_LOG,"isamd_reduce:  got  p=%d c=%d sz=%d",
+       pp->pos, pp->cat, pp->size);    
+} /* reduceblock */
 
 
-ISAMD_P isamd_append (ISAMD is, ISAMD_P ipos, ISAMD_I data)
+static int save_first_pp ( ISAMD_PP firstpp)
+{
+   isamd_buildfirstblock(firstpp);
+   isamd_write_block(firstpp->is,firstpp->cat,firstpp->pos,firstpp->buf);
+   return isamd_addr(firstpp->pos,firstpp->cat);
+}
+
+ 
+static void save_last_pp (ISAMD_PP pp)
+{
+   pp->next = 0;/* just to be sure */
+   isamd_buildlaterblock(pp);
+   isamd_write_block(pp->is,pp->cat,pp->pos,pp->buf);
+}
+
+#ifdef UNUSED
+static int save_both_pps (ISAMD_PP firstpp, ISAMD_PP pp)
+{
+   /* order of things: Better to save firstpp first, if there are just two */
+   /* blocks, but last if there are blocks in between, as these have already */
+   /* been saved... optimise later (that's why this is in its own func...*/
+   int retval = save_first_pp(firstpp);
+   if (firstpp!=pp){ 
+      save_last_pp(pp);
+      isamd_pp_close(pp);
+   }
+   isamd_pp_close(firstpp);
+   return retval;
+} /* save_both_pps */
+#endif
+
+
+
+/***************************************************************
+ * Diffblock handling
+ ***************************************************************/
+
+void isamd_free_diffs(ISAMD_PP pp)
+{
+  int i;
+  if (pp->is->method->debug > 5)
+     logf(LOG_LOG,"isamd_free_diffs: pp=%p di=%p", pp, pp->diffinfo);
+  if (!pp->diffinfo) 
+    return;
+  for (i=0;pp->diffinfo[i].difftype!=DT_NONE;i++) 
+      if(pp->diffinfo[i].decodeData)
+      {
+          if (pp->is->method->debug > 8)
+             logf(LOG_LOG,"isamd_free_diffs [%d]=%p",i, 
+                           pp->diffinfo[i].decodeData);
+          (*pp->is->method->code_stop)(ISAMD_DECODE,pp->diffinfo[i].decodeData);
+      } 
+  xfree(pp->diffinfo);
+  if (pp->diffbuf != pp->buf)
+    xfree (pp->diffbuf);  
+  pp->diffbuf=0;
+  pp->diffinfo=0;
+} /* isamd_free_diffs */
+
+
+static void getDiffInfo(ISAMD_PP pp )
+{ /* builds the diff info structures from a diffblock */
+   int maxinfos = pp->is->method->filecat[pp->cat].bsize / 5 +2;
+    /* Each diff takes at least 5 bytes. Probably more, but this is safe */
+   int i=1;  /* [0] is used for the main data, [n+1] for merge inputs */
+   int diffsz= maxinfos * sizeof(struct ISAMD_DIFF_s);
+   int maxsz = pp->is->method->filecat[pp->is->max_cat].bsize;
+   int diffidx = ISAMD_BLOCK_OFFSET_1;
+
+   pp->diffinfo = xmalloc( diffsz ); 
+   pp->offset = pp->size+1; /* used this block up */
+   memset(pp->diffinfo,'\0',diffsz);
+   if (pp->is->method->debug > 5)   
+      logf(LOG_LOG,"isamd_getDiffInfo: %d=%d:%d->%d, ix=%d mx=%d",
+         isamd_addr(pp->pos, pp->cat), pp->cat, pp->pos, pp->next,
+         diffidx,maxinfos);
+   
+   /* duplicate the buffer for diffs */
+   /* (so that we can read the next real buffer(s) */
+   assert(0==pp->diffbuf);
+   pp->diffbuf=xmalloc(maxsz);
+   memcpy(pp->diffbuf, pp->buf, maxsz);
+   
+   pp->diffinfo[0].maxidx=-1; /* mark as special */
+   pp->diffinfo[0].difftype=DT_MAIN;
+
+   while (i<maxinfos) 
+   {  
+      if ( diffidx+sizeof(int) > pp->is->method->filecat[pp->cat].bsize )
+      {
+         if (pp->is->method->debug > 5)
+           logf(LOG_LOG,"isamd_getDiffInfo:Near end (no room for len) at ix=%d n=%d",
+               diffidx, i);
+         return; /* whole block done */
+      }
+      memcpy( &pp->diffinfo[i].maxidx, &pp->diffbuf[diffidx], sizeof(int) );
+      pp->diffinfo[i].difftype=DT_DIFF;
+      if (pp->is->method->debug > 5)
+        logf(LOG_LOG,"isamd_getDiffInfo: max=%d ix=%d dbuf=%p",
+          pp->diffinfo[i].maxidx, diffidx, pp->diffbuf);
+
+      if ( (pp->is->method->debug > 0) &&
+         (pp->diffinfo[i].maxidx > pp->is->method->filecat[pp->cat].bsize) )
+      { 
+         logf(LOG_LOG,"Bad MaxIx!!! %s:%d: diffidx=%d", 
+                       __FILE__,__LINE__, diffidx);
+         logf(LOG_LOG,"i=%d maxix=%d bsz=%d", i, pp->diffinfo[i].maxidx,
+                       pp->is->method->filecat[pp->cat].bsize);
+         logf(LOG_LOG,"pp=%d=%d:%d  pp->nx=%d=%d:%d",
+                       isamd_addr(pp->pos,pp->cat), pp->pos, pp->cat,
+                       pp->next, isamd_type(pp->next), isamd_block(pp->next) );                      
+      }
+      assert(pp->diffinfo[i].maxidx <= pp->is->method->filecat[pp->cat].bsize+1);
+
+      if (0==pp->diffinfo[i].maxidx)
+      {
+         if (pp->is->method->debug > 5)  //!!! 4
+           logf(LOG_LOG,"isamd_getDiffInfo:End mark at ix=%d n=%d",
+               diffidx, i);
+         return; /* end marker */
+      }
+      diffidx += sizeof(int);
+      pp->diffinfo[i].decodeData = (*pp->is->method->code_start)(ISAMD_DECODE);
+      pp->diffinfo[i].diffidx = diffidx;
+      if (pp->is->method->debug > 5)
+        logf(LOG_LOG,"isamd_getDiff[%d]:%d-%d %s",
+          i,diffidx-sizeof(int),pp->diffinfo[i].maxidx,
+          hexdump((char *)&pp->diffbuf[diffidx-4],8,0) );
+      diffidx=pp->diffinfo[i].maxidx;
+      if ( diffidx > pp->is->method->filecat[pp->cat].bsize )
+        return; /* whole block done */
+      ++i;
+   }
+   assert (!"too many diff sequences in the block");
+}
+
+/***************************************************************
+ * Main block operations
+ ***************************************************************/
+
+
+static ISAMD_PP get_new_main_block( ISAMD_PP firstpp, ISAMD_PP pp)
+{  /* allocates a new block for the main data, and links it in */
+  int newblock;
+  if (0 == firstpp->next) 
+  {  /* special case, pp not yet allocated. */
+     /*Started as largest size, that's fine */
+     pp->pos = isamd_alloc_block(pp->is,pp->cat);
+     firstpp->next = isamd_addr(pp->pos,pp->cat);
+     if (pp->is->method->debug >3) 
+        logf(LOG_LOG,"isamd_build: Alloc 1. dblock  p=%d=%d:%d",
+           isamd_addr(pp->pos,pp->cat), pp->cat, pp->pos);
+  }
+  newblock=isamd_alloc_block(pp->is,pp->cat);
+  pp->next=isamd_addr(newblock,pp->cat);
+  isamd_buildlaterblock(pp);
+  isamd_write_block(pp->is,pp->cat,pp->pos,pp->buf);
+  if (pp->is->method->debug >3) 
+     logf(LOG_LOG,"isamd_build: Alloc nxt %d=%d:%d -> %d=%d:%d",
+        isamd_addr(pp->pos,pp->cat), pp->cat, pp->pos,
+        isamd_addr(newblock,pp->cat), pp->cat, newblock);
+  pp->next=0;
+  pp->pos=newblock;
+  pp->size=pp->offset=ISAMD_BLOCK_OFFSET_N;  
+  return pp;
+} /* get_new_main_block */
+
+
+static ISAMD_PP  append_main_item(ISAMD_PP firstpp, 
+                                  ISAMD_PP pp, 
+                                  struct it_key *i_key)
+{  /* appends one item in the main data block, allocates new if needed */
+   char *i_item= (char *) i_key;  /* same as char */
+   char *i_ptr=i_item;
+   char codebuff[128];
+   char *c_ptr = codebuff;
+   int codelen;
+   char hexbuff[64];
+
+   int maxsize = pp->is->method->filecat[pp->is->max_cat].bsize; 
+
+   c_ptr=codebuff;
+   i_ptr=i_item;
+   (*pp->is->method->code_item)(ISAMD_ENCODE, pp->decodeClientData,
+                                &c_ptr, &i_ptr);
+   codelen = c_ptr - codebuff;
+   assert ( (codelen<128) && (codelen>0));
+   if (pp->is->method->debug >7)
+      logf(LOG_LOG,"isamd:build: coded %s nk=%d,ofs=%d-%d",
+          hexdump(codebuff, c_ptr-codebuff,hexbuff), firstpp->numKeys+1,
+          pp->offset, pp->offset+codelen);
+
+   if (pp->offset + codelen > maxsize )
+   { /* oops, block full - get a new one */
+      pp =  get_new_main_block( firstpp, pp );
+      /* reset encoging and code again */
+      (*pp->is->method->code_reset)(pp->decodeClientData);
+      c_ptr=codebuff;
+      i_ptr=i_item;
+      (*pp->is->method->code_item)(ISAMD_ENCODE, pp->decodeClientData, 
+                                   &c_ptr, &i_ptr);
+      codelen = c_ptr - codebuff;
+      assert ( (codelen<128) && (codelen>0));
+      if (pp->is->method->debug >7)
+         logf(LOG_LOG,"isamd:build: recoded into %s  (nk=%d)",
+             hexdump(codebuff, c_ptr-codebuff,hexbuff), firstpp->numKeys+1);
+   } /* block full */    
+
+   assert (pp->offset + codelen <= maxsize );
+   
+   /* write the data into pp, now we must have room */ 
+   memcpy(&(pp->buf[pp->offset]),codebuff,codelen);
+   pp->offset += codelen;
+   pp->size += codelen;
+   firstpp->numKeys++;
+   /* clear the next 4 bytes in block, to avoid confusions with diff lens */
+   /* dirty, it should not be done here, but something slips somewhere, and */
+   /* I hope this fixes it...  - Heikki */
+   codelen = pp->offset;
+   while ( (codelen < maxsize ) && (codelen <= pp->offset+4) )
+     pp->buf[codelen++] = '\0';
+   return pp;    
+} /* append_main_item */
+
+
+/***************************************************************
+ * Read with merge
+ ***************************************************************/
+
+/* Reads one item and corrects for the diffs, if any */
+/* return 1 for ok, 0 for eof */
+int isamd_read_item_merge (
+                     ISAMD_PP pp, 
+                     char **dst,
+                     struct it_key *p_key,  /* the data item that didn't fit*/
+              /*       ISAMD_I data)  */    /* more input data comes here */
+                     FILTER filt)           /* more input data comes here */
+{                    /* The last two args can be null for ordinary reads */
+  char *keyptr;
+  char *codeptr;
+  char *codestart;
+  int winner=0; /* which diff holds the day */
+  int i; /* looping diffs */
+  int cmp;
+  int retry=1;
+  int oldoffs;
+  int rc;
+
+  if (!pp->diffinfo)  
+  { /* first time */
+     getDiffInfo(pp);
+
+     for(i=1; pp->diffinfo[i].difftype!=DT_NONE; i++)
+       ;  /* find last diff */
+     if (p_key)  
+     {  /* we have an extra item to inject into the merge */
+       if (pp->is->method->debug >9)  //!!!!!
+          logf(LOG_LOG,"isamd_read_item: going to merge with %d.%d",
+               p_key->sysno, p_key->seqno);
+       pp->diffinfo[i].key = *p_key;  /* the key merge could not handle */
+       pp->diffinfo[i].mode = pp->diffinfo[i].key.seqno & 1;
+       pp->diffinfo[i].key.seqno >>= 1;
+       pp->diffinfo[i].difftype=DT_INPU;
+       if (pp->is->method->debug > 7)
+         logf(LOG_LOG,"isamd_read_item: inpu key %d sys=%d  seq=%d=2*%d+%d",
+            i, p_key->sysno,
+            pp->diffinfo[i].key.seqno*2 + pp->diffinfo[1].mode,
+            pp->diffinfo[i].key.seqno,
+            pp->diffinfo[i].mode);
+       p_key->sysno=p_key->seqno=0;  /* used it up */
+     }
+
+     if (filt)
+     { /* we have a whole input stream to inject */
+       pp->diffinfo[i].difftype=DT_INPU;
+     }
+  } /* first time */ 
+        
+  while (retry)
+
+  {
+     retry=0;     
+     winner = 0;
+     for (i=0; (!retry) && (pp->diffinfo[i].difftype); i++)
+     {
+        if (0==pp->diffinfo[i].key.sysno)
+        {/* read a new one, if possible */
+           if ((pp->diffinfo[i].difftype==DT_DIFF) &&
+             (pp->diffinfo[i].diffidx < pp->diffinfo[i].maxidx))
+           { /* a normal kind of diff */
+              oldoffs=pp->diffinfo[i].diffidx;
+              codeptr= codestart = &(pp->diffbuf[pp->diffinfo[i].diffidx]);
+              keyptr=(char *)&(pp->diffinfo[i].key);
+              (*pp->is->method->code_item)(ISAMD_DECODE,
+                    pp->diffinfo[i].decodeData, &keyptr, &codeptr);
+              pp->diffinfo[i].diffidx += codeptr-codestart;
+              pp->diffinfo[i].mode = pp->diffinfo[i].key.seqno & 1;
+              pp->diffinfo[i].key.seqno = pp->diffinfo[i].key.seqno >>1 ;
+              if (pp->is->method->debug > 9)
+                logf(LOG_LOG,"isamd_read_item: dif[%d] at %d-%d: %s",
+                  i,oldoffs, pp->diffinfo[i].diffidx,
+                  hexdump(pp->buf+oldoffs, pp->diffinfo[i].diffidx-oldoffs,0));
+              if (pp->is->method->debug > 7)
+                logf(LOG_LOG,"isamd_read_item: rd dif[%d] %d.%d (%x.%x)",
+                  i,
+                  pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                  pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno);
+           }
+           else if ( pp->diffinfo[i].difftype==DT_MAIN)
+           { /* read a main item */
+              assert(i==0);  /* main data goes before any diffs */
+              oldoffs=pp->offset;
+              keyptr=(char*) &(pp->diffinfo[0].key);
+              rc= isamd_read_main_item(pp,&keyptr);
+              if (0==rc) 
+              { /* eof */
+                 if (pp->is->method->debug > 7)
+                   logf(LOG_LOG,"isamd_read_item: eof (rc=%d) main ",
+                           rc);
+                pp->diffinfo[i].maxidx=-1;
+                pp->diffinfo[i].key.sysno=0;
+                pp->diffinfo[i].key.seqno=0;
+                pp->diffinfo[i].difftype= DT_DONE;
+              } 
+              else
+              { /* not eof */
+                 pp->diffinfo[i].mode = 1;
+                 if (pp->is->method->debug > 7)
+                   logf(LOG_LOG,"isamd_read_item: rd main %d-%d %d.%d (%x.%x) m=%d",
+                     oldoffs,pp->offset,
+                     pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                     pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                     pp->diffinfo[i].mode);
+              } /* not eof */
+           }
+           else if (pp->diffinfo[i].difftype==DT_INPU)
+           {
+              keyptr = (char *) &pp->diffinfo[i].key;
+         /*     rc = (*data->read_item)(data->clientData, &keyptr, &pp->diffinfo[i].mode); */
+              rc = filter_read(filt, &pp->diffinfo[i].key, 
+                                     &pp->diffinfo[i].mode); 
+              if (!rc) 
+              {  /* did not get it */
+                 pp->diffinfo[i].key.sysno=0;
+                 pp->diffinfo[i].maxidx=0; /* signal the end */
+                 pp->diffinfo[i].difftype=DT_DONE;
+              }
+              if (pp->is->method->debug >7)
+                 logf(LOG_LOG,"merge: read inpu m=%d %d.%d (%x.%x)",
+                    pp->diffinfo[i].mode, 
+                    pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                    pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno );        
+           } /* read an input item */
+        } /* read a new one */
+        
+        if (pp->is->method->debug > 8)
+          logf(LOG_LOG,"isamd_read_item: considering d%d %d.%d ix=%d mx=%d",
+               i, pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                  pp->diffinfo[i].diffidx,   pp->diffinfo[i].maxidx);
+            
+        if ( 0!= pp->diffinfo[i].key.sysno)
+        { /* got a key, compare */
+          if (i!=winner)
+             cmp=key_compare(&pp->diffinfo[i].key, &pp->diffinfo[winner].key);
+          else
+             cmp=-1;
+          if (0==pp->diffinfo[winner].key.sysno)
+            cmp=-1; /* end of main sequence, take all diffs */
+          if (cmp<0)
+          {
+             if (pp->is->method->debug > 8)
+               logf(LOG_LOG,"isamd_read_item: ins [%d]%d.%d < [%d]%d.%d",
+                 i,  
+                 pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                 winner, 
+                 pp->diffinfo[winner].key.sysno, pp->diffinfo[winner].key.seqno);
+             if (pp->diffinfo[i].mode)  /* insert diff, should always be */
+               winner = i;
+             else
+             {
+               if (pp->is->method->debug > 1)
+                 logf(LOG_LOG,"delete diff for nonexisting item");
+               assert(!"delete diff for nonexisting item");  
+               /* is an assert too steep here? Not really.*/
+             }
+          } /* earlier key */
+          else if (cmp==0)
+          {
+             if (!pp->diffinfo[i].mode) /* delete diff. should always be */
+             {
+                if (pp->is->method->debug > 8)
+                  logf(LOG_LOG,"isamd_read_item: del %d at%d %d.%d (%x.%x)",
+                    i, winner,
+                    pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                    pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno);
+                pp->diffinfo[winner].key.sysno=0; /* delete it */
+             }
+             else
+                if (pp->is->method->debug > 2)
+                  logf(LOG_LOG,"isamd_read_item: duplicate ins %d at%d %d.%d (%x.%x)",
+                    i, winner,
+                    pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno,
+                    pp->diffinfo[i].key.sysno, pp->diffinfo[i].key.seqno);
+                /* skip the insert, since we already have it in the base */
+                /* Should we fail an assertion here??? */
+             pp->diffinfo[i].key.sysno=0; /* done with the delete */
+             retry=1; /* start all over again */
+          } /* matching key */
+          /* else it is a later key, its turn will come */
+        } /* got a key */
+     } /* for each diff */
+  } /* not retry */
+
+  if ( pp->diffinfo[winner].key.sysno)
+  {
+    if (pp->is->method->debug > 7)
+      logf(LOG_LOG,"isamd_read_item: got %d  %d.%d (%x.%x)",
+        winner,
+        pp->diffinfo[winner].key.sysno, pp->diffinfo[winner].key.seqno,
+        pp->diffinfo[winner].key.sysno, pp->diffinfo[winner].key.seqno);
+    memcpy(*dst, &pp->diffinfo[winner].key, sizeof(struct it_key) );
+    *dst += sizeof(struct it_key);
+    pp->diffinfo[winner].key.sysno=0; /* used that one up */
+    cmp= 1;
+  } 
+  else 
+  {
+    if (pp->is->method->debug > 7)
+      logf(LOG_LOG,"isamd_read_item: eof w=%d  %d.%d (%x.%x)",
+        winner,
+        pp->diffinfo[winner].key.sysno, pp->diffinfo[winner].key.seqno,
+        pp->diffinfo[winner].key.sysno, pp->diffinfo[winner].key.seqno);
+    assert(winner==0); /* if nothing found, nothing comes from a diff */
+    cmp= 0; /* eof */
+  }
+  if (cmp)
+    ++(pp->is->no_read_keys);
+  else
+    ++(pp->is->no_read_eof);
+
+  return cmp;
+   
+} /* isamd_read_item */
+
+
+int isamd_read_item (ISAMD_PP pp, char **dst)
 {
+  return isamd_read_item_merge(pp,dst,0,0);
+}
+
+
+/***************************************************************
+ * Merge
+ ***************************************************************/
+
+static int merge ( ISAMD_PP firstpp,      /* first pp (with diffs) */
+                   struct it_key *p_key,  /* the data item that didn't fit*/
+              /*     ISAMD_I data) */     /* more input data comes here */
+                   FILTER filt)           /* more input data arriving here */
+{
+  int diffidx;  
+  int killblk=0;
+  struct it_key r_key;
+  char * r_ptr;
+  int r_more = 1;
+  ISAMD_PP pp;
+  ISAMD_PP readpp=firstpp;
+  int retval=0;
+  int diffcat = firstpp->cat;  /* keep the category of the diffblock even */
+                               /* if it is going to be empty now. */
+                               /* Alternative: Make it the minimal, and */
+                               /* resize later. Saves disk, but will lead */
+                               /* into bad seeks. */
+  
+  ++(readpp->is->no_merges);
+     
+  /* set up diffs as they should be for reading */
+  diffidx = ISAMD_BLOCK_OFFSET_1; 
+  //readpp->diffbuf=readpp->buf;  // diffinfo has to duplicate it!
+  //getDiffInfo(readpp);  // first read will make the diffinfo, at init
+  
+  if (readpp->is->method->debug >4) 
+      logf(LOG_LOG,"isamd_merge: f=%d=%d:%d n=%d=%d:%d",
+        isamd_addr(firstpp->pos,firstpp->cat), firstpp->cat, firstpp->pos,
+        firstpp->next, isamd_type(firstpp->next), isamd_block(firstpp->next));  
+
+  /* release our data block. Do before reading, when pos is stable ! */
+  killblk=firstpp->pos;
+  if (killblk)
+  {
+      isamd_release_block(firstpp->is, firstpp->cat, killblk);
+      if (readpp->is->method->debug >3)   
+          logf(LOG_LOG,"isamd_merge: released old firstblock %d (%d:%d)",
+              isamd_addr(killblk,firstpp->cat), firstpp->cat, killblk );
+  }
+  
+
+  r_ptr= (char *) &r_key;
+/*  r_more = isamd_read_item_merge( readpp, &r_ptr, p_key, data); */
+  r_more = isamd_read_item_merge( readpp, &r_ptr, p_key, filt);
+  if (!r_more)  
+  { /* oops, all data has been deleted! what to do??? */
+    /* never mind, we have at least one more delta to add to the block */
+    /* pray that is not a delete as well... */
+    r_key.sysno = 0;
+    r_key.seqno = 0;
+     if (readpp->is->method->debug >5) 
+         logf(LOG_LOG,"isamd_merge:all data has been deleted (nk=%d) ",
+            readpp->numKeys);
+  }
+
+
+  /* set up the new blocks for simple writing */
+  firstpp=isamd_pp_open(readpp->is,isamd_addr(0, diffcat));
+  firstpp->pos=isamd_alloc_block(firstpp->is,diffcat);
+  if (readpp->is->method->debug >3)   
+      logf(LOG_LOG,"isamd_merge: allocated new firstpp %d=%d:%d",
+          isamd_addr(firstpp->pos,firstpp->cat), firstpp->cat, firstpp->pos );
+  
+  pp=isamd_pp_open(readpp->is,isamd_addr(0,readpp->is->max_cat) );
+  pp->offset=pp->size=ISAMD_BLOCK_OFFSET_N;
+  
+  while (r_more)
+  {
+     if (readpp->is->method->debug >6) 
+         logf(LOG_LOG,"isamd_merge: got key %d.%d",
+           r_key.sysno, r_key.seqno );
+     pp= append_main_item(firstpp, pp, &r_key);
+
+     if ( (readpp->pos != killblk ) && (0!=readpp->pos) )
+     {  /* pos can get to 0 at end of main seq, if still diffs left...*/
+        if (readpp->is->method->debug >3)  
+            logf(LOG_LOG,"isamd_merge: released block %d (%d:%d) now %d=%d:%d",
+                isamd_addr(killblk,readpp->cat), readpp->cat, killblk,
+                isamd_addr(readpp->pos,readpp->cat),readpp->cat, readpp->pos );
+        isamd_release_block(readpp->is, readpp->cat, readpp->pos);
+        killblk=readpp->pos;
+     }
+
+     /* (try to) read next item */
+     r_ptr= (char *) &r_key;
+     r_more = isamd_read_item_merge( readpp, &r_ptr,0,filt);
+
+  } /* while read */
+  
+  
+//  firstpp->diffs=0; 
+
+
+  isamd_reduceblock(pp);  /* reduce size if possible */
+  if (0==firstpp->next)
+    firstpp->next = isamd_addr(pp->pos,pp->cat);
+  save_last_pp(pp);
+  if (readpp->is->method->debug >4) 
+      logf(LOG_LOG,"isamd_merge: saved last block %d=%d:%d",
+            isamd_addr(pp->pos,pp->cat), pp->cat, pp->pos);
+  isamd_pp_close(pp);
+
+  if (readpp->is->method->debug >5) 
+        logf(LOG_LOG,"isamd_merge: closing readpp %d=%d:%d di=%p",
+              isamd_addr(readpp->pos,readpp->cat), readpp->cat, readpp->pos,
+              readpp->diffinfo);
+  isamd_pp_close(readpp); /* pos is 0 by now, at eof. close works anyway */
+
+  if (readpp->is->method->debug >2)  
+      logf(LOG_LOG,"isamd_merge: merge ret f=%d=%d:%d pp=%d=%d:%d",
+            isamd_addr(firstpp->pos,pp->cat), firstpp->cat, firstpp->pos,
+            isamd_addr(pp->pos,pp->cat), pp->cat, pp->pos);
+
+  firstpp->size = firstpp->offset = ISAMD_BLOCK_OFFSET_1;  /* nothing there */
+  memset(firstpp->buf,'\0',firstpp->is->method->filecat[firstpp->cat].bsize);
+  save_first_pp(firstpp);
+  retval = isamd_addr(firstpp->pos, firstpp->cat);
+  isamd_pp_close(firstpp);
+
+  return retval; 
+  
+} /* merge */
+
+
+
+
+/***************************************************************
+ * Appending diffs 
+ ***************************************************************/
+
+
+
+static int append_diffs(
+      ISAMD is, 
+      ISAMD_P ipos, 
+      /*ISAMD_I data)*/
+      FILTER filt)
+{
+   struct it_key i_key;    /* one input item */
+   char *i_item = (char *) &i_key;  /* same as chars */
+   char *i_ptr=i_item;
+   int i_more =1;
+   int i_mode;     /* 0 for delete, 1 for insert */ 
+
+   ISAMD_PP firstpp;
+   char hexbuff[64];
+   int diffidx=0;
+   int maxsize=0;
+   int difflenidx;
+   char codebuff[128];
+   char *c_ptr = codebuff;
+   int codelen;
+   int merge_rc;
+   int retval=0;
+
+   if (0==ipos)
+   {
+       firstpp=isamd_pp_open(is, isamd_addr(0,0) );
+       firstpp->size=firstpp->offset=ISAMD_BLOCK_OFFSET_1;
+         /* create in smallest category, will expand later */
+       ++(is->no_fbuilds);
+   } 
+   else
+   {
+       firstpp=isamd_pp_open(is, ipos);
+       ++(is->no_appds);
+   }
+
+   if (is->method->debug >2) 
+      logf(LOG_LOG,"isamd_appd: Start ipos=%d=%d:%d n=%d=%d:%d nk=%d",
+        ipos, isamd_type(ipos), isamd_block(ipos),
+        firstpp->next, isamd_type(firstpp->next), isamd_block(firstpp->next),
+        firstpp->numKeys);
+   maxsize = is->method->filecat[firstpp->cat].bsize; 
+   
+   difflenidx = diffidx = firstpp->size;
+   
+   diffidx+=sizeof(int);  /* difflen will be stored here */
+   
+   /* read first input */
+   //i_ptr = i_item;   //!!!
+   i_more = filter_read(filt, &i_key, &i_mode); 
+   /* i_more = (*data->read_item)(data->clientData, &i_ptr, &i_mode); */
+
+   if (is->method->debug >6)
+      logf(LOG_LOG,"isamd_appd: start m=%d %d.%d=%x.%x: %d",
+         i_mode, 
+         i_key.sysno, i_key.seqno, 
+         i_key.sysno, i_key.seqno,
+         i_key.sysno*2+i_mode);
+
+   while (i_more)
+   {     
+      /* store the mode bit inside key */
+      assert( ((i_key.seqno<<1)>>1) == i_key.seqno); /* can spare the bit */
+      i_key.seqno = i_key.seqno * 2 + i_mode;  
+
+      c_ptr=codebuff;
+      i_ptr=i_item; 
+      (*is->method->code_item)(ISAMD_ENCODE, firstpp->decodeClientData, 
+                               &c_ptr, &i_ptr);
+      codelen = c_ptr - codebuff;
+      assert ( (codelen<128) && (codelen>0));
+      if (is->method->debug >7)
+         logf(LOG_LOG,"isamd_appd: coded %d: %s (nk=%d) (ix=%d)",
+             codelen, hexdump(codebuff, codelen,hexbuff), 
+             firstpp->numKeys,diffidx);
+
+      if (diffidx + codelen > maxsize )
+      { /* block full */
+         while ( (firstpp->cat < firstpp->is->max_cat) &&
+                 (diffidx + codelen > maxsize) )
+         { /* try to increase the block size */
+             if (firstpp->pos > 0)  /* free the old block if allocated */
+                 isamd_release_block(is, firstpp->cat, firstpp->pos);
+             ++firstpp->cat;
+             maxsize = is->method->filecat[firstpp->cat].bsize; 
+             firstpp->pos=0; /* need to allocate it when saving */             
+             if (is->method->debug >3)
+                logf(LOG_LOG,"isamd_appd: increased diff block sz to %d (%d)",
+                   firstpp->cat, maxsize);
+         }
+         if  ((firstpp->cat >= firstpp->is->max_cat) &&
+                 (diffidx + codelen > maxsize) )
+         { /* max size - can't help, need to merge it */
+             if (is->method->debug >7)
+                logf(LOG_LOG,"isamd_appd: need to merge");
+             if (is->method->debug >9)  //!!!!!
+                logf(LOG_LOG,"isamd_appd: going to merge with m=%d %d.%d",
+                     i_mode, i_key.sysno, i_key.seqno);
+             merge_rc = merge (firstpp, &i_key, filt);
+             if (0!=merge_rc)
+               return merge_rc;  /* merge handled them all ! */
+             assert(!"merge returned zero ??");
+         } /* need to merge */
+      } /* block full */
+
+      if (!( diffidx+codelen <= maxsize )) 
+      { /* bug hunting */
+         logf(LOG_LOG,"OOPS, diffidx problem: d=%d c=%d s=%d > m=%d",
+           diffidx, codelen, diffidx+codelen, maxsize);
+         logf(LOG_LOG,"ipos=%d f=%d=%d:%d",
+           ipos, 
+           isamd_addr(firstpp->pos, firstpp->cat),
+           firstpp->cat, firstpp->pos );
+      }
+      assert ( diffidx+codelen <= maxsize );
+      
+      /* save the diff */ 
+      memcpy(&(firstpp->buf[diffidx]),codebuff,codelen);
+      diffidx += codelen;
+      firstpp->size = firstpp->offset = diffidx;
+      
+      if (i_mode)
+        firstpp->numKeys++; /* insert diff */
+      else
+        firstpp->numKeys--; /* delete diff */ 
+
+      /* update length of this diff run */
+      memcpy(&(firstpp->buf[difflenidx]),&diffidx,sizeof(diffidx));
+      
+      /* (try to) read the next input */
+      i_ptr = i_item;
+      i_more = filter_read(filt, &i_key, &i_mode); 
+    /*  i_more = (*data->read_item)(data->clientData, &i_ptr, &i_mode); */
+      if ( (i_more) && (is->method->debug >6) )
+         logf(LOG_LOG,"isamd_appd: got m=%d %d.%d=%x.%x: %d",
+            i_mode, 
+            i_key.sysno, i_key.seqno, 
+            i_key.sysno, i_key.seqno,
+            i_key.sysno*2+i_mode);
+   } /* more loop */
+
+   /* clear the next difflen, if room for such */
+   difflenidx = diffidx;
+   while ( (difflenidx-diffidx<=sizeof(int)+1) && (difflenidx<maxsize))
+     firstpp->buf[difflenidx++]='\0';
+
+   if (0==firstpp->pos)  /* need to (re)alloc the block */
+      firstpp->pos = isamd_alloc_block(is, firstpp->cat);
+
+   retval = save_first_pp( firstpp );
+   isamd_pp_close(firstpp);
     
-} /*  isamh_append */
+   return retval;
+} /* append_diffs */
+
+
+
+
+/*************************************************************
+ * isamd_append itself
+ *************************************************************/
+
+ISAMD_P isamd_append (ISAMD is, ISAMD_P ipos, ISAMD_I data)
+{
+   FILTER F = filter_open(is,data);
+   ISAMD_P rc=0;
+
+   int olddebug= is->method->debug;
+   if (ipos == 7320)
+     is->method->debug = 99;  /*!*/
+     
+   if ( filter_isempty(F) ) /* can be, if del-ins of the same */
+   {
+      if (is->method->debug >3) 
+         logf(LOG_LOG,"isamd_appd: nothing to do for %d=",ipos);
+      filter_close(F);
+      ++(is->no_non);
+      return ipos; /* without doing anything at all */
+   }
+
+   if ( ( 0==ipos) && filter_only_one(F) )
+   {
+      struct it_key k;
+      int mode;
+      filter_read(F,&k,&mode);     
+      assert(mode); 
+      rc = singleton_encode(&k);
+      if (is->method->debug >9) 
+         logf(LOG_LOG,"isamd_appd: singleton %d (%x)",
+           rc,rc);
+      if (rc)
+        is->no_singles++;
+      assert ( (rc==0) || is_singleton(rc) );
+   }
+   if ( 0==rc) /* either not single, or it did not fit */
+   {
+      rc = append_diffs(is,ipos,F); 
+      assert ( ! is_singleton(rc) ); 
+        /* can happen if we run out of bits, so that block numbers overflow */
+        /* to SINGLETON_BIT */
+   }
+   filter_close(F);
+
+   if (is->method->debug >2) 
+      logf(LOG_LOG,"isamd_appd: ret %d=%x (%d=%x)",
+        rc,rc,ipos,ipos);
+   is->method->debug=olddebug; /*!*/
+   return rc;
+} /*  isamd_append */
+
+
+
+
+
 
 
 /*
  * $Log: merge-d.c,v $
- * Revision 1.1  1999-07-14 13:14:47  heikki
+ * Revision 1.25  1999-11-30 13:48:04  adam
+ * Improved installation. Updated for inclusion of YAZ header files.
+ *
+ * Revision 1.24  1999/10/05 09:57:40  heikki
+ * Tuning the isam-d (and fixed a small "detail")
+ *
+ * Revision 1.23  1999/09/27 14:36:36  heikki
+ * singletons
+ *
+ * Revision 1.22  1999/09/23 18:01:18  heikki
+ * singleton optimising
+ *
+ * Revision 1.21  1999/09/21 17:36:43  heikki
+ * Added filter function. Not much of effect on the small test set...
+ *
+ * Revision 1.20  1999/09/20 15:48:06  heikki
+ * Small changes
+ *
+ * Revision 1.19  1999/09/13 13:28:28  heikki
+ * isam-d optimizing: merging input data in the same go
+ *
+ * Revision 1.18  1999/08/25 18:09:24  heikki
+ * Starting to optimize
+ *
+ * Revision 1.17  1999/08/24 13:17:42  heikki
+ * Block sizes, comments
+ *
+ * Revision 1.16  1999/08/24 10:12:02  heikki
+ * Comments about optimising
+ *
+ * Revision 1.15  1999/08/22 08:26:34  heikki
+ * COmments
+ *
+ * Revision 1.14  1999/08/20 12:25:58  heikki
+ * Statistics in isamd
+ *
+ * Revision 1.13  1999/08/18 13:59:19  heikki
+ * Fixed another unlikely difflen bug
+ *
+ * Revision 1.12  1999/08/18 13:28:17  heikki
+ * Set log levels to decent values
+ *
+ * Revision 1.11  1999/08/18 10:37:11  heikki
+ * Fixed (another) difflen bug
+ *
+ * Revision 1.10  1999/08/18 09:13:31  heikki
+ * Fixed a detail
+ *
+ * Revision 1.9  1999/08/17 19:46:53  heikki
+ * Fixed a memory leak
+ *
+ * Revision 1.8  1999/08/07 11:30:59  heikki
+ * Bug fixing (still a mem leak somewhere)
+ *
+ * Revision 1.7  1999/08/04 14:21:18  heikki
+ * isam-d seems to be working.
+ *
+ * Revision 1.6  1999/07/23 15:43:05  heikki
+ * Hunted a few bugs in isam-d. Still crashes on the long test run
+ *
+ * Revision 1.5  1999/07/23 13:58:52  heikki
+ * merged closer to working, still fails on filling a separate, large block
+ *
+ * Revision 1.4  1999/07/21 14:53:55  heikki
+ * isamd read and write functions work, except when block full
+ * Merge missing still. Need to split some functions
+ *
+ * Revision 1.1  1999/07/14 13:14:47  heikki
  * Created empty
  *
  *