isamc.c

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/* $Id: isamc.c,v 1.23 2003/06/23 15:36:11 adam Exp $
   Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003
   Index Data Aps

This file is part of the Zebra server.

Zebra is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Zebra; see the file LICENSE.zebra.  If not, write to the
Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.
*/



/* 
 * TODO:
 *   Reduction to lower categories in isc_merge
 */
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <stdio.h>

#include <yaz/log.h>
#include "isamc-p.h"

static void flush_block (ISAMC is, int cat);
static void release_fc (ISAMC is, int cat);
static void init_fc (ISAMC is, int cat);

#define ISAMC_FREELIST_CHUNK 1

#define SMALL_TEST 0

void isc_getmethod (ISAMC_M *m)
{

    static struct ISAMC_filecat_s def_cat[] = {
#if SMALL_TEST
        {    32,     28,      0,  3 },
	{    64,     54,     30,  0 },
#else
        {    32,     26,     20,  10 },
	{   128,    120,    100,  10 },
        {   512,    490,    350,  10 },
        {  2048,   1900,   1700,  10 },
        {  8192,   8000,   7900,  10 },
        { 32768,  32000,  31000,  0 },
#endif
    };
    m->filecat = def_cat;

    m->code_start = NULL;
    m->code_item = NULL;
    m->code_stop = NULL;
    m->code_reset = NULL;

    m->compare_item = NULL;

    m->debug = 1;

    m->max_blocks_mem = 10;
}

ISAMC isc_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method)
{
    ISAMC is;
    ISAMC_filecat filecat;
    int i = 0;
    int max_buf_size = 0;

    is = (ISAMC) xmalloc (sizeof(*is));

    is->method = (ISAMC_M *) xmalloc (sizeof(*is->method));
    memcpy (is->method, method, sizeof(*method));
    filecat = is->method->filecat;
    assert (filecat);

    /* determine number of block categories */
    if (is->method->debug)
        logf (LOG_LOG, "isc: bsize  ifill  mfill mblocks");
    do
    {
        if (is->method->debug)
            logf (LOG_LOG, "isc:%6d %6d %6d %6d",
                  filecat[i].bsize, filecat[i].ifill, 
                  filecat[i].mfill, filecat[i].mblocks);
        if (max_buf_size < filecat[i].mblocks * filecat[i].bsize)
            max_buf_size = filecat[i].mblocks * filecat[i].bsize;
    } while (filecat[i++].mblocks);
    is->no_files = i;
    is->max_cat = --i;
    /* max_buf_size is the larget buffer to be used during merge */
    max_buf_size = (1 + max_buf_size / filecat[i].bsize) * filecat[i].bsize;
    if (max_buf_size < (1+is->method->max_blocks_mem) * filecat[i].bsize)
        max_buf_size = (1+is->method->max_blocks_mem) * filecat[i].bsize;
    if (is->method->debug)
        logf (LOG_LOG, "isc: max_buf_size %d", max_buf_size);
    
    assert (is->no_files > 0);
    is->files = (ISAMC_file) xmalloc (sizeof(*is->files)*is->no_files);
    if (writeflag)
    {
        is->merge_buf = (char *) xmalloc (max_buf_size+256);
	memset (is->merge_buf, 0, max_buf_size+256);
    }
    else
        is->merge_buf = NULL;
    for (i = 0; i<is->no_files; i++)
    {
        char fname[512];

        sprintf (fname, "%s%c", name, i+'A');
        is->files[i].bf = bf_open (bfs, fname, is->method->filecat[i].bsize,
                                   writeflag);
        is->files[i].head_is_dirty = 0;
        if (!bf_read (is->files[i].bf, 0, 0, sizeof(ISAMC_head),
                     &is->files[i].head))
        {
            is->files[i].head.lastblock = 1;
            is->files[i].head.freelist = 0;
        }
	is->files[i].alloc_entries_num = 0;
	is->files[i].alloc_entries_max =
	    is->method->filecat[i].bsize / sizeof(int) - 1;
	is->files[i].alloc_buf = (char *)
	    xmalloc (is->method->filecat[i].bsize);
        is->files[i].no_writes = 0;
        is->files[i].no_reads = 0;
        is->files[i].no_skip_writes = 0;
        is->files[i].no_allocated = 0;
        is->files[i].no_released = 0;
        is->files[i].no_remap = 0;
	is->files[i].no_forward = 0;
	is->files[i].no_backward = 0;
	is->files[i].sum_forward = 0;
	is->files[i].sum_backward = 0;
	is->files[i].no_next = 0;
	is->files[i].no_prev = 0;

        init_fc (is, i);
    }
    return is;
}

int isc_block_used (ISAMC is, int type)
{
    if (type < 0 || type >= is->no_files)
	return -1;
    return is->files[type].head.lastblock-1;
}

int isc_block_size (ISAMC is, int type)
{
    ISAMC_filecat filecat = is->method->filecat;
    if (type < 0 || type >= is->no_files)
	return -1;
    return filecat[type].bsize;
}

int isc_close (ISAMC is)
{
    int i;

    if (is->method->debug)
    {
	logf (LOG_LOG, "isc:    next    forw   mid-f    prev   backw   mid-b");
	for (i = 0; i<is->no_files; i++)
	    logf (LOG_LOG, "isc:%8d%8d%8.1f%8d%8d%8.1f",
		  is->files[i].no_next,
		  is->files[i].no_forward,
		  is->files[i].no_forward ?
		  (double) is->files[i].sum_forward/is->files[i].no_forward
		  : 0.0,
		  is->files[i].no_prev,
		  is->files[i].no_backward,
		  is->files[i].no_backward ?
		  (double) is->files[i].sum_backward/is->files[i].no_backward
		  : 0.0);
    }
    if (is->method->debug)
        logf (LOG_LOG, "isc:  writes   reads skipped   alloc released  remap");
    for (i = 0; i<is->no_files; i++)
    {
        release_fc (is, i);
        assert (is->files[i].bf);
        if (is->files[i].head_is_dirty)
            bf_write (is->files[i].bf, 0, 0, sizeof(ISAMC_head),
                 &is->files[i].head);
        if (is->method->debug)
            logf (LOG_LOG, "isc:%8d%8d%8d%8d%8d%8d",
                  is->files[i].no_writes,
                  is->files[i].no_reads,
                  is->files[i].no_skip_writes,
                  is->files[i].no_allocated,
                  is->files[i].no_released,
                  is->files[i].no_remap);
        xfree (is->files[i].fc_list);
	flush_block (is, i);
        bf_close (is->files[i].bf);
    }
    xfree (is->files);
    xfree (is->merge_buf);
    xfree (is->method);
    xfree (is);
    return 0;
}

int isc_read_block (ISAMC is, int cat, int pos, char *dst)
{
    ++(is->files[cat].no_reads);
    return bf_read (is->files[cat].bf, pos, 0, 0, dst);
}

int isc_write_block (ISAMC is, int cat, int pos, char *src)
{
    ++(is->files[cat].no_writes);
    if (is->method->debug > 2)
        logf (LOG_LOG, "isc: write_block %d %d", cat, pos);
    return bf_write (is->files[cat].bf, pos, 0, 0, src);
}

int isc_write_dblock (ISAMC is, int cat, int pos, char *src,
                      int nextpos, int offset)
{
    ISAMC_BLOCK_SIZE size = offset + ISAMC_BLOCK_OFFSET_N;
    if (is->method->debug > 2)
        logf (LOG_LOG, "isc: write_dblock. size=%d nextpos=%d",
              (int) size, nextpos);
    src -= ISAMC_BLOCK_OFFSET_N;
    memcpy (src, &nextpos, sizeof(int));
    memcpy (src + sizeof(int), &size, sizeof(size));
    return isc_write_block (is, cat, pos, src);
}

#if ISAMC_FREELIST_CHUNK
static void flush_block (ISAMC is, int cat)
{
    char *abuf = is->files[cat].alloc_buf;
    int block = is->files[cat].head.freelist;
    if (block && is->files[cat].alloc_entries_num)
    {
	memcpy (abuf, &is->files[cat].alloc_entries_num, sizeof(int));
	bf_write (is->files[cat].bf, block, 0, 0, abuf);
	is->files[cat].alloc_entries_num = 0;
    }
    xfree (abuf);
}

static int alloc_block (ISAMC is, int cat)
{
    int block = is->files[cat].head.freelist;
    char *abuf = is->files[cat].alloc_buf;

    (is->files[cat].no_allocated)++;

    if (!block)
    {
        block = (is->files[cat].head.lastblock)++;   /* no free list */
	is->files[cat].head_is_dirty = 1;
    }
    else
    {
	if (!is->files[cat].alloc_entries_num) /* read first time */
	{
	    bf_read (is->files[cat].bf, block, 0, 0, abuf);
	    memcpy (&is->files[cat].alloc_entries_num, abuf,
		    sizeof(is->files[cat].alloc_entries_num));
	    assert (is->files[cat].alloc_entries_num > 0);
	}
	/* have some free blocks now */