/* This file is part of the Zebra server.
Copyright (C) Index Data
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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <yaz/log.h>
#include <yaz/xmalloc.h>
#include <idzebra/isams.h>
typedef struct {
int last_offset;
int last_block;
} ISAMS_head;
typedef unsigned ISAMS_BLOCK_SIZE;
struct ISAMS_s {
ISAMS_M *method;
ISAMS_head head;
ISAMS_head head_old;
char *merge_buf;
int block_size;
int debug;
BFile bf;
};
struct ISAMS_PP_s {
ISAMS is;
char *buf;
int block_offset;
int block_no;
void *decodeClientData;
int numKeys;
int numRead;
};
void isams_getmethod (ISAMS_M *m)
{
m->codec.start = NULL;
m->codec.decode = NULL;
m->codec.encode = NULL;
m->codec.stop = NULL;
m->codec.reset = NULL;
m->compare_item = NULL;
m->log_item = NULL;
m->debug = 1;
m->block_size = 128;
}
ISAMS isams_open (BFiles bfs, const char *name, int writeflag,
ISAMS_M *method)
{
ISAMS is = (ISAMS) xmalloc (sizeof(*is));
is->method = (ISAMS_M *) xmalloc (sizeof(*is->method));
memcpy (is->method, method, sizeof(*method));
is->block_size = is->method->block_size;
is->debug = is->method->debug;
is->bf = bf_open (bfs, name, is->block_size, writeflag);
if (!bf_read (is->bf, 0, 0, sizeof(ISAMS_head), &is->head))
{
is->head.last_block = 1;
is->head.last_offset = 0;
}
memcpy (&is->head_old, &is->head, sizeof(is->head));
is->merge_buf = (char *) xmalloc(2*is->block_size);
memset(is->merge_buf, 0, 2*is->block_size);
return is;
}
int isams_close (ISAMS is)
{
if (memcmp(&is->head, &is->head_old, sizeof(is->head)))
{
if (is->head.last_offset)
bf_write(is->bf, is->head.last_block, 0, is->head.last_offset,
is->merge_buf);
bf_write (is->bf, 0, 0, sizeof(is->head), &is->head);
}
bf_close (is->bf);
xfree (is->merge_buf);
xfree (is->method);
xfree (is);
return 0;
}
ISAM_P isams_merge (ISAMS is, ISAMS_I data)
{
char i_item[128];
int i_more, i_mode;
void *r_clientData;
int first_block = is->head.last_block;
int first_offset = is->head.last_offset;
int count = 0;
r_clientData = (*is->method->codec.start)();
is->head.last_offset += sizeof(int);
if (is->head.last_offset > is->block_size)
{
if (is->debug > 2)
yaz_log (YLOG_LOG, "first_block=%d", first_block);
bf_write(is->bf, is->head.last_block, 0, 0, is->merge_buf);
(is->head.last_block)++;
is->head.last_offset -= is->block_size;
memcpy (is->merge_buf, is->merge_buf + is->block_size,
is->head.last_offset);
}
while (1)
{
char *tmp_ptr = i_item;
i_more = (*data->read_item)(data->clientData, &tmp_ptr, &i_mode);
assert (i_mode);
if (!i_more)
break;
else
{
char *r_out_ptr = is->merge_buf + is->head.last_offset;
const char *i_item_ptr = i_item;
(*is->method->codec.encode)(r_clientData, &r_out_ptr, &i_item_ptr);
is->head.last_offset = r_out_ptr - is->merge_buf;
if (is->head.last_offset > is->block_size)
{
bf_write(is->bf, is->head.last_block, 0, 0, is->merge_buf);
(is->head.last_block)++;
is->head.last_offset -= is->block_size;
memcpy (is->merge_buf, is->merge_buf + is->block_size,
is->head.last_offset);
}
count++;
}
}
(*is->method->codec.stop)(r_clientData);
if (first_block == is->head.last_block)
memcpy(is->merge_buf + first_offset, &count, sizeof(int));
else if (first_block == is->head.last_block-1)
{
int gap = first_offset + sizeof(int) - is->block_size;
assert (gap <= (int) sizeof(int));
if (gap > 0)
{
if (gap < (int) sizeof(int))
bf_write(is->bf, first_block, first_offset, sizeof(int)-gap,
&count);
memcpy (is->merge_buf, ((char*)&count)+(sizeof(int)-gap), gap);
}
else
bf_write(is->bf, first_block, first_offset, sizeof(int), &count);
}
else
{
bf_write(is->bf, first_block, first_offset, sizeof(int), &count);
}
return first_block * is->block_size + first_offset;
}
ISAMS_PP isams_pp_open (ISAMS is, ISAM_P pos)
{
ISAMS_PP pp = (ISAMS_PP) xmalloc (sizeof(*pp));
if (is->debug > 1)
yaz_log (YLOG_LOG, "isams: isams_pp_open pos=%ld", (long) pos);
pp->is = is;
pp->decodeClientData = (*is->method->codec.start)();
pp->numKeys = 0;
pp->numRead = 0;
pp->buf = (char *) xmalloc(is->block_size*2);
pp->block_no = (int) (pos/is->block_size);
pp->block_offset = (int) (pos - pp->block_no * is->block_size);
if (is->debug)
yaz_log (YLOG_LOG, "isams: isams_pp_open off=%d no=%d",
pp->block_offset, pp->block_no);
if (pos)
{
bf_read (is->bf, pp->block_no, 0, 0, pp->buf);
bf_read (is->bf, pp->block_no+1, 0, 0, pp->buf + is->block_size);
memcpy(&pp->numKeys, pp->buf + pp->block_offset, sizeof(int));
if (is->debug)
yaz_log (YLOG_LOG, "isams: isams_pp_open numKeys=%d", pp->numKeys);
pp->block_offset += sizeof(int);
}
return pp;
}
void isams_pp_close (ISAMS_PP pp)
{
(*pp->is->method->codec.stop)(pp->decodeClientData);
xfree(pp->buf);
xfree(pp);
}
int isams_pp_num (ISAMS_PP pp)
{
return pp->numKeys;
}
int isams_pp_read (ISAMS_PP pp, void *buf)
{
char *cp = buf;
return isams_read_item (pp, &cp);
}
int isams_read_item (ISAMS_PP pp, char **dst)
{
const char *src;
if (pp->numRead >= pp->numKeys)
return 0;
(pp->numRead)++;
if (pp->block_offset > pp->is->block_size)
{
pp->block_offset -= pp->is->block_size;
(pp->block_no)++;
memcpy (pp->buf, pp->buf + pp->is->block_size, pp->is->block_size);
bf_read (pp->is->bf, pp->block_no+1, 0, 0,
pp->buf + pp->is->block_size);
}
src = pp->buf + pp->block_offset;
(*pp->is->method->codec.decode)(pp->decodeClientData, dst, &src);
pp->block_offset = src - pp->buf;
return 1;
}
/*
* Local variables:
* c-basic-offset: 4
* c-file-style: "Stroustrup"
* indent-tabs-mode: nil
* End:
* vim: shiftwidth=4 tabstop=8 expandtab
*/