isamd.c

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	memcpy (abuf + sizeof(int), &block, sizeof(int));
	is->files[cat].head.freelist = pos;
	is->files[cat].head_is_dirty = 1; 
    }
    else
    {
	memcpy (abuf + sizeof(int) +
		is->files[cat].alloc_entries_num*sizeof(int),
		&pos, sizeof(int));
    }
    is->files[cat].alloc_entries_num++;
}
#else
static void flush_block (ISAMD is, int cat)
{
    char *abuf = is->files[cat].alloc_buf;
    xfree (abuf);
}

static int alloc_block (ISAMD is, int cat)
{
    int block;
    char buf[sizeof(int)];

    is->files[cat].head_is_dirty = 1;
    (is->files[cat].no_allocated)++;
    if ((block = is->files[cat].head.freelist))
    {
        bf_read (is->files[cat].bf, block, 0, sizeof(int), buf);
        memcpy (&is->files[cat].head.freelist, buf, sizeof(int));
    }
    else
        block = (is->files[cat].head.lastblock)++;
    return block;
}

static void release_block (ISAMD is, int cat, int pos)
{
    char buf[sizeof(int)];
   
    (is->files[cat].no_released)++;
    is->files[cat].head_is_dirty = 1; 
    memcpy (buf, &is->files[cat].head.freelist, sizeof(int));
    is->files[cat].head.freelist = pos;
    bf_write (is->files[cat].bf, pos, 0, sizeof(int), buf);
}
#endif

int isamd_alloc_block (ISAMD is, int cat)
{
    int block = 0;

    if (is->files[cat].fc_list)
    {
        int j, nb;
        for (j = 0; j < is->files[cat].fc_max; j++)
            if ((nb = is->files[cat].fc_list[j]) && (!block || nb < block))
            {
                is->files[cat].fc_list[j] = 0;
		block = nb;
                break;
            }
    }
    if (!block)
        block = alloc_block (is, cat);
    if (is->method->debug > 4)
        logf (LOG_LOG, "isamd: alloc_block in cat %d: %d", cat, block);
    return block;
}

void isamd_release_block (ISAMD is, int cat, int pos)
{
    if (is->method->debug > 4)
        logf (LOG_LOG, "isamd: release_block in cat %d: %d", cat, pos);
    assert(pos!=0);
    
    if (is->files[cat].fc_list)
    {
        int j;
        for (j = 0; j<is->files[cat].fc_max; j++)
            if (!is->files[cat].fc_list[j])
            {
                is->files[cat].fc_list[j] = pos;
                return;
            }
    }
    release_block (is, cat, pos);
}

static void init_fc (ISAMD is, int cat)
{
    int j = 100;
        
    is->files[cat].fc_max = j;
    is->files[cat].fc_list = (int *)
	xmalloc (sizeof(*is->files[0].fc_list) * j);
    while (--j >= 0)
        is->files[cat].fc_list[j] = 0;
}

static void release_fc (ISAMD is, int cat)
{
    int b, j = is->files[cat].fc_max;

    while (--j >= 0)
        if ((b = is->files[cat].fc_list[j]))
        {
            release_block (is, cat, b);
            is->files[cat].fc_list[j] = 0;
        }
}

void isamd_pp_close (ISAMD_PP pp)
{
    ISAMD is = pp->is;

    (*is->method->code_stop)(ISAMD_DECODE, pp->decodeClientData);
    isamd_free_diffs(pp);  /* see merge-d.h */
    if (is->method->debug > 5)
       logf (LOG_LOG, "isamd_pp_close %p %d=%d:%d  sz=%d n=%d=%d:%d nk=%d",
             pp, isamd_addr(pp->pos, pp->cat), pp->cat, pp->pos, pp->size, 
             pp->next, isamd_type(pp->next), isamd_block(pp->next), 
             pp->numKeys );
    xfree (pp->buf);
    xfree (pp);
}


ISAMD_PP isamd_pp_create (ISAMD is, int cat)
/* creates a pp_buff without data in it. pos=0, cat as given */
{
    ISAMD_PP pp = (ISAMD_PP) xmalloc (sizeof(*pp));
    int sz = is->method->filecat[is->max_cat].bsize;

    pp->numKeys = 0;
    pp->buf = (char *) xmalloc (sz);
    memset(pp->buf,'\0',sz); /* clear the buffer, for new blocks */
    
    pp->next = 0;
    pp->size = 0;
    pp->offset = 0;
    pp->is = is;
    pp->diffs=0;
    pp->diffbuf=0;
    pp->diffinfo=0;
    pp->decodeClientData = (*is->method->code_start)(ISAMD_DECODE);
    pp->cat = cat;
    pp->pos = 0;
    is->no_op_new++; 
    return pp;
      
}


ISAMD_PP isamd_pp_open (ISAMD is, const char *dictbuf, int dictlen)
{
    ISAMD_P ipos;
    ISAMD_PP pp = (ISAMD_PP) xmalloc (sizeof(*pp));
    char *src;
    int sz = is->method->filecat[is->max_cat].bsize;
                 /* always allocate for the largest blocks, saves trouble */
    int dictnum;
    
    pp->numKeys = 0;
    src = pp->buf = (char *) xmalloc (sz);
    memset(src,'\0',sz); /* clear the buffer, for new blocks */
    
    pp->next = 0;
    pp->size = 0;
    pp->offset = 0;
    pp->is = is;
    pp->diffs=0;
    pp->diffbuf=0;
    pp->diffinfo=0;
    pp->decodeClientData = (*is->method->code_start)(ISAMD_DECODE);
    
    dictnum=*dictbuf;  /* numkeys for internals, 0 for externals */

    if (0==dictnum)
    {
        memcpy(&ipos, dictbuf+1, sizeof(ISAMD_P) );
    }
    else /* dictionary block, fake a real one */
    {
       pp->cat=0; 
       pp->pos=0;
       if (is->method->debug > 5)
          logf (LOG_LOG, "isamd_pp_open dict");
       pp->numKeys=(unsigned char) dictbuf[0];
       memcpy(pp->buf+ISAMD_BLOCK_OFFSET_1, dictbuf+1,dictlen-1);
       pp->size=pp->offset=dictlen+ISAMD_BLOCK_OFFSET_1-1;
       is->no_op_single++;
       return pp;
    } /* dict block */
   
    pp->cat = isamd_type(ipos);
    pp->pos = isamd_block(ipos); 
    
    if (0==pp->pos)
      is->no_op_new++; 
      
    if (pp->pos)
    {
        src = pp->buf;
        isamd_read_block (is, pp->cat, pp->pos, src);
        memcpy (&pp->next, src, sizeof(pp->next));
        src += sizeof(pp->next);
        memcpy (&pp->size, src, sizeof(pp->size));
        src += sizeof(pp->size);
        memcpy (&pp->numKeys, src, sizeof(pp->numKeys));
        src += sizeof(pp->numKeys);
        assert (pp->next != isamd_addr(pp->pos,pp->cat));
        pp->offset = src - pp->buf; 
        assert (pp->offset == ISAMD_BLOCK_OFFSET_1);
        assert(pp->size>=ISAMD_BLOCK_OFFSET_1); /*??*/
        if (pp->next)
          is->files[pp->cat].no_op_main++;
        else
          is->files[pp->cat].no_op_diffonly++;
    }
    if (is->method->debug > 5)
       logf (LOG_LOG, "isamd_pp_open  %p %d=%d:%d  sz=%d n=%d=%d:%d",
             pp, isamd_addr(pp->pos, pp->cat), pp->cat, pp->pos, pp->size, 
             pp->next, isamd_type(pp->next), isamd_block(pp->next) );

    return pp;
}



void isamd_buildfirstblock(ISAMD_PP pp){
  char *dst=pp->buf;
  assert(pp->buf);
  assert(pp->next != isamd_addr(pp->pos,pp->cat)); 
  memcpy(dst, &pp->next, sizeof(pp->next) );
  dst += sizeof(pp->next);
  memcpy(dst, &pp->size,sizeof(pp->size));
  dst += sizeof(pp->size);
  memcpy(dst, &pp->numKeys, sizeof(pp->numKeys));
  dst += sizeof(pp->numKeys);
  assert (dst - pp->buf  == ISAMD_BLOCK_OFFSET_1);
  if (pp->is->method->debug > 5)
     logf (LOG_LOG, "isamd: bldfirst:  p=%d=%d:%d n=%d:%d:%d sz=%d nk=%d ",
           isamd_addr(pp->pos,pp->cat),pp->cat, pp->pos, 
           pp->next, isamd_type(pp->next), isamd_block(pp->next),
           pp->size, pp->numKeys);
}

void isamd_buildlaterblock(ISAMD_PP pp){
  char *dst=pp->buf;
  assert(pp->buf);
  assert(pp->next != isamd_addr(pp->pos,pp->cat)); 
  memcpy(dst, &pp->next, sizeof(pp->next) );
  dst += sizeof(pp->next);
  memcpy(dst, &pp->size,sizeof(pp->size));
  dst += sizeof(pp->size);
  assert (dst - pp->buf  == ISAMD_BLOCK_OFFSET_N);
  if (pp->is->method->debug > 5)
     logf (LOG_LOG, "isamd: l8r: sz=%d  p=%d/%d>%d/%d",
           pp->size, 
           pp->pos, pp->cat, 
           isamd_block(pp->next), isamd_type(pp->next) );
}



/* returns non-zero if item could be read; 0 otherwise */
int isamd_pp_read (ISAMD_PP pp, void *buf)
{

    return isamd_read_item (pp, (char **) &buf);
       /* note: isamd_read_item is in merge-d.c, because it is so */
       /* convoluted with the merge process */
}

/* read one main item from file - decode and store it in *dst.
   Does not worry about diffs
   Returns
     0 if end-of-file
     1 if item could be read ok
*/
int isamd_read_main_item (ISAMD_PP pp, char **dst)
{
    ISAMD is = pp->is;
    char *src = pp->buf + pp->offset;
    int newcat;
    int oldoffs;

    if (pp->offset >= pp->size)
    {
	if (!pp->next)
	{
	    pp->pos = 0;
	    return 0; /* end of file */
	}
	if (pp->next > pp->pos)
	{
	    if (pp->next == pp->pos + 1)
		is->files[pp->cat].no_next++;
	    else
	    {
		is->files[pp->cat].no_forward++;
		is->files[pp->cat].sum_forward += pp->next - pp->pos;
	    }
	}
	else
	{
	    if (pp->next + 1 == pp->pos)
		is->files[pp->cat].no_prev++;
	    else
	    {
		is->files[pp->cat].no_backward++;
		is->files[pp->cat].sum_backward += pp->pos - pp->next;
	    }
	}
	/* out new block position */
	newcat = isamd_type(pp->next);
        pp->pos = isamd_block(pp->next);
        pp->cat = isamd_type(pp->next);
        pp->is->no_read_main++;
        src = pp->buf;
	/* read block and save 'next' and 'size' entry */
        isamd_read_block (is, pp->cat, pp->pos, src);
        memcpy (&pp->next, src, sizeof(pp->next));
        src += sizeof(pp->next);
        memcpy (&pp->size, src, sizeof(pp->size));
        src += sizeof(pp->size);
        /* assume block is non-empty */
        pp->offset = oldoffs = src - pp->buf; 
        assert (pp->offset == ISAMD_BLOCK_OFFSET_N);
        assert (pp->next != isamd_addr(pp->pos,pp->cat));
        (*is->method->code_reset)(pp->decodeClientData);
        /* finally, read the item */
        (*is->method->code_item)(ISAMD_DECODE, pp->decodeClientData, dst, &src);
        pp->offset = src - pp->buf; 
        if (is->method->debug > 8)
            logf (LOG_LOG, "isamd: read_m: block %d:%d sz=%d ofs=%d-%d next=%d",
                 pp->cat, pp->pos, pp->size, oldoffs, pp->offset, pp->next);
        return 2;
    }
    oldoffs=pp->offset;
    (*is->method->code_item)(ISAMD_DECODE, pp->decodeClientData, dst, &src);
    pp->offset = src - pp->buf; 
    if (is->method->debug > 8)
        logf (LOG_LOG, "isamd: read_m: got %d:%d sz=%d ofs=%d-%d next=%d",
             pp->cat, pp->pos, pp->size, oldoffs, pp->offset, pp->next);
    return 1;
}

int isamd_pp_num (ISAMD_PP pp)
{
    return pp->numKeys;
}

#if 0
/* for testing .. */
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;
}
#endif

#ifdef SKIPTHIS
  /* needs different arguments, or something */
void isamd_pp_dump (ISAMD is, ISAMD_P ipos)
{
  ISAMD_PP pp;
  ISAMD_P oldaddr=0;
  struct it_key key;
  int i,n;
  int occur =0;
  int oldoffs;
  int diffmax=1;
  int diffidx;
  char hexbuff[64];
  int olddebug= is->method->debug;
  is->method->debug=0; /* no debug logs while reading for dump */
  
  logf(LOG_LOG,"dumping isamd block %d (%d:%d)",
                  (int)ipos, isamd_type(ipos), isamd_block(ipos) );
  pp=isamd_pp_open(is,ipos);
  logf(LOG_LOG,"numKeys=%d,  ofs=%d sz=%d",
       pp->numKeys, pp->offset, pp->size );
  diffidx=oldoffs= pp->offset;
  while ((diffidx < is->method->filecat[pp->cat].bsize) && (diffmax>0))
  {
    memcpy(&diffmax,&(pp->buf[diffidx]),sizeof(int));
    logf (LOG_LOG,"diff set at %d-%d: %s", diffidx, diffmax, 
      hexdump(pp->buf+diffidx,8,0)); 
      /*! todo: dump the actual diffs as well !!! */
    diffidx=diffmax;
    
  } /* dump diffs */
  while(isamd_pp_read(pp, &key))
  {
     if (oldaddr != isamd_addr(pp->pos,pp->cat) )
     {
        oldaddr = isamd_addr(pp->pos,pp->cat); 
        logf(LOG_LOG,"block %d=%d:%d sz=%d nx=%d=%d:%d ofs=%d",
                  isamd_addr(pp->pos,pp->cat), pp->cat, pp->pos, 
                  pp->size,
                  pp->next, isamd_type(pp->next), isamd_block(pp->next),
                  pp->offset);
        i=0;      
        while (i<pp->size) {
          n=pp->size-i;
          if (n>8) n=8;
          logf(LOG_LOG,"  %05x: %s",i,hexdump(pp->buf+i,n,hexbuff));
          i+=n;
        }
        if (oldoffs >  ISAMD_BLOCK_OFFSET_N)
           oldoffs=ISAMD_BLOCK_OFFSET_N;
     } /* new block */
     occur++;
     logf (LOG_LOG,"    got %d:%d=%x:%x from %s at %d=%x",
      	          key.sysno, key.seqno,
	          key.sysno, key.seqno,
	          hexdump(pp->buf+oldoffs, pp->offset-oldoffs, hexbuff),
	          oldoffs, oldoffs);
     oldoffs = pp->offset;
  }
  /*!*/ /*TODO: dump diffs too!!! */
  isamd_pp_close(pp);
  is->method->debug=olddebug;
} /* dump */

#endif