/* $Id: isamb.c,v 1.47.2.4 2005/01/16 23:13:30 adam Exp $
Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
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.
*/
#include <string.h>
#include <stdlib.h>
#include <yaz/xmalloc.h>
#include <yaz/log.h>
#include <isamb.h>
#include <assert.h>
#ifndef ISAMB_DEBUG
#define ISAMB_DEBUG 0
#endif
struct ISAMB_head {
int first_block;
int last_block;
int block_size;
int block_max;
int free_list;
};
#define ISAMB_DATA_OFFSET 3
/* maximum size of encoded buffer */
#define DST_ITEM_MAX 256
#define ISAMB_MAX_LEVEL 10
/* approx 2*max page + max size of item */
#define DST_BUF_SIZE 16840
#define ISAMB_CACHE_ENTRY_SIZE 4096
/* CAT_MAX: _must_ be power of 2 */
#define CAT_MAX 4
#define CAT_MASK (CAT_MAX-1)
/* CAT_NO: <= CAT_MAX */
#define CAT_NO 4
/* ISAMB_PTR_CODEC=1 var, =0 fixed */
#define ISAMB_PTR_CODEC 0
struct ISAMB_cache_entry {
ISAMB_P pos;
unsigned char *buf;
int dirty;
int hits;
struct ISAMB_cache_entry *next;
};
struct ISAMB_file {
BFile bf;
int head_dirty;
struct ISAMB_head head;
struct ISAMB_cache_entry *cache_entries;
};
struct ISAMB_s {
BFiles bfs;
ISAMC_M *method;
struct ISAMB_file *file;
int no_cat;
int cache; /* 0=no cache, 1=use cache, -1=dummy isam (for testing only) */
int log_io; /* log level for bf_read/bf_write calls */
int log_freelist; /* log level for freelist handling */
int skipped_numbers; /* on a leaf node */
int returned_numbers;
int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
};
struct ISAMB_block {
ISAMB_P pos;
int cat;
int size;
int leaf;
int dirty;
int deleted;
int offset;
char *bytes;
char *cbuf;
unsigned char *buf;
void *decodeClientData;
int log_rw;
};
struct ISAMB_PP_s {
ISAMB isamb;
ISAMB_P pos;
int level;
int maxlevel; /* total depth */
int total_size;
int no_blocks;
int skipped_numbers; /* on a leaf node */
int returned_numbers;
int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
struct ISAMB_block **block;
};
#if ISAMB_PTR_CODEC
static void encode_ptr (char **dst, unsigned pos)
{
unsigned char *bp = (unsigned char*) *dst;
while (pos > 127)
{
*bp++ = 128 | (pos & 127);
pos = pos >> 7;
}
*bp++ = pos;
*dst = (char *) bp;
}
#else
static void encode_ptr (char **dst, unsigned pos)
{
memcpy(*dst, &pos, sizeof(pos));
(*dst) += sizeof(pos);
}
#endif
#if ISAMB_PTR_CODEC
static void decode_ptr (char **src1, int *pos)
{
unsigned char **src = (unsigned char **) src1;
unsigned d = 0;
unsigned char c;
unsigned r = 0;
while (((c = *(*src)++) & 128))
{
d += ((c & 127) << r);
r += 7;
}
d += (c << r);
*pos = d;
}
#else
static void decode_ptr (char **src, int *pos)
{
memcpy (pos, *src, sizeof(*pos));
(*src) += sizeof(*pos);
}
#endif
ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method,
int cache)
{
ISAMB isamb = xmalloc (sizeof(*isamb));
int i, b_size = 32;
isamb->bfs = bfs;
isamb->method = (ISAMC_M *) xmalloc (sizeof(*method));
memcpy (isamb->method, method, sizeof(*method));
isamb->no_cat = CAT_NO;
isamb->log_io = 0;
isamb->log_freelist = 0;
isamb->cache = cache;
isamb->skipped_numbers=0;
isamb->returned_numbers=0;
for (i=0;i<ISAMB_MAX_LEVEL;i++)
isamb->skipped_nodes[i]= isamb->accessed_nodes[i]=0;
assert (cache == 0);
isamb->file = xmalloc (sizeof(*isamb->file) * isamb->no_cat);
for (i = 0; i<isamb->no_cat; i++)
{
char fname[DST_BUF_SIZE];
isamb->file[i].cache_entries = 0;
isamb->file[i].head_dirty = 0;
sprintf (fname, "%s%c", name, i+'A');
if (cache)
isamb->file[i].bf = bf_open (bfs, fname, ISAMB_CACHE_ENTRY_SIZE,
writeflag);
else
isamb->file[i].bf = bf_open (bfs, fname, b_size, writeflag);
if (!bf_read (isamb->file[i].bf, 0, 0, sizeof(struct ISAMB_head),
&isamb->file[i].head))
{
isamb->file[i].head.first_block = ISAMB_CACHE_ENTRY_SIZE/b_size+1;
isamb->file[i].head.last_block = isamb->file[i].head.first_block;
isamb->file[i].head.block_size = b_size;
isamb->file[i].head.block_max = b_size - ISAMB_DATA_OFFSET;
isamb->file[i].head.free_list = 0;
}
assert (isamb->file[i].head.block_size >= ISAMB_DATA_OFFSET);
isamb->file[i].head_dirty = 0;
assert(isamb->file[i].head.block_size == b_size);
b_size = b_size * 4;
}
#if ISAMB_DEBUG
logf(LOG_WARN, "isamb debug enabled. Things will be slower than usual");
#endif
return isamb;
}
static void flush_blocks (ISAMB b, int cat)
{
while (b->file[cat].cache_entries)
{
struct ISAMB_cache_entry *ce_this = b->file[cat].cache_entries;
b->file[cat].cache_entries = ce_this->next;
if (ce_this->dirty)
{
yaz_log (b->log_io, "bf_write: flush_blocks");
bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
}
xfree (ce_this->buf);
xfree (ce_this);
}
}
static int get_block (ISAMB b, ISAMC_P pos, char *userbuf, int wr)
{
int cat = pos&CAT_MASK;
int off = ((pos/CAT_MAX) &
(ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size - 1))
* b->file[cat].head.block_size;
int norm = pos / (CAT_MASK*ISAMB_CACHE_ENTRY_SIZE / b->file[cat].head.block_size);
int no = 0;
struct ISAMB_cache_entry **ce, *ce_this = 0, **ce_last = 0;
if (!b->cache)
return 0;
assert (ISAMB_CACHE_ENTRY_SIZE >= b->file[cat].head.block_size);
for (ce = &b->file[cat].cache_entries; *ce; ce = &(*ce)->next, no++)
{
ce_last = ce;
if ((*ce)->pos == norm)
{
ce_this = *ce;
*ce = (*ce)->next; /* remove from list */
ce_this->next = b->file[cat].cache_entries; /* move to front */
b->file[cat].cache_entries = ce_this;
if (wr)
{
memcpy (ce_this->buf + off, userbuf,
b->file[cat].head.block_size);
ce_this->dirty = 1;
}
else
memcpy (userbuf, ce_this->buf + off,
b->file[cat].head.block_size);
return 1;
}
}
if (no >= 40)
{
assert (no == 40);
assert (ce_last && *ce_last);
ce_this = *ce_last;
*ce_last = 0; /* remove the last entry from list */
if (ce_this->dirty)
{
yaz_log (b->log_io, "bf_write: get_block");
bf_write (b->file[cat].bf, ce_this->pos, 0, 0, ce_this->buf);
}
xfree (ce_this->buf);
xfree (ce_this);
}
ce_this = xmalloc (sizeof(*ce_this));
ce_this->next = b->file[cat].cache_entries;
b->file[cat].cache_entries = ce_this;
ce_this->buf = xmalloc (ISAMB_CACHE_ENTRY_SIZE);
ce_this->pos = norm;
yaz_log (b->log_io, "bf_read: get_block");
if (!bf_read (b->file[cat].bf, norm, 0, 0, ce_this->buf))
memset (ce_this->buf, 0, ISAMB_CACHE_ENTRY_SIZE);
if (wr)
{
memcpy (ce_this->buf + off, userbuf, b->file[cat].head.block_size);
ce_this->dirty = 1;
}
else
{
ce_this->dirty = 0;
memcpy (userbuf, ce_this->buf + off, b->file[cat].head.block_size);
}
return 1;
}
void isamb_close (ISAMB isamb)
{
int i;
for (i=0;isamb->accessed_nodes[i];i++)
logf(LOG_DEBUG,"isamb_close level leaf-%d: %d read, %d skipped",
i, isamb->accessed_nodes[i], isamb->skipped_nodes[i]);
logf(LOG_DEBUG,"isamb_close returned %d values, skipped %d",
isamb->skipped_numbers, isamb->returned_numbers);
for (i = 0; i<isamb->no_cat; i++)
{
flush_blocks (isamb, i);
if (isamb->file[i].head_dirty)
bf_write (isamb->file[i].bf, 0, 0,
sizeof(struct ISAMB_head), &isamb->file[i].head);
bf_close (isamb->file[i].bf);
}
xfree (isamb->file);
xfree (isamb->method);
xfree (isamb);
}
static struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
{
int cat = pos&CAT_MASK;
struct ISAMB_block *p;
if (!pos)
return 0;
p = xmalloc (sizeof(*p));
p->pos = pos;
p->cat = pos & CAT_MASK;
p->buf = xmalloc (b->file[cat].head.block_size);
p->cbuf = 0;
if (!get_block (b, pos, p->buf, 0))
{
yaz_log (b->log_io, "bf_read: open_block");
if (!bf_read (b->file[cat].bf, pos/CAT_MAX, 0, 0, p->buf))
{
yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
(long) pos, (long) pos/CAT_MAX);
abort();
}
}
p->bytes = p->buf + ISAMB_DATA_OFFSET;
p->leaf = p->buf[0];
p->size = (p->buf[1] + 256 * p->buf[2]) - ISAMB_DATA_OFFSET;
if (p->size < 0)
{
yaz_log (LOG_FATAL, "Bad block size %d in pos=%d\n", p->size, pos);
}
assert (p->size >= 0);
p->offset = 0;
p->dirty = 0;
p->deleted = 0;
p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
yaz_log (LOG_DEBUG, "isamb_open_block: Opened block %d ofs=%d",pos, p->offset);
return p;
}
struct ISAMB_block *new_block (ISAMB b, int leaf, int cat)
{
struct ISAMB_block *p;
p = xmalloc (sizeof(*p));
p->buf = xmalloc (b->file[cat].head.block_size);
if (!b->file[cat].head.free_list)
{
int block_no;
block_no = b->file[cat].head.last_block++;
p->pos = block_no * CAT_MAX + cat;
}
else
{
p->pos = b->file[cat].head.free_list;
assert((p->pos & CAT_MASK) == cat);
if (!get_block (b, p->pos, p->buf, 0))
{
yaz_log (b->log_io, "bf_read: new_block");
if (!bf_read (b->file[cat].bf, p->pos/CAT_MAX, 0, 0, p->buf))
{
yaz_log (LOG_FATAL, "isamb: read fail for pos=%ld block=%ld",
(long) p->pos/CAT_MAX, (long) p->pos/CAT_MAX);
abort ();
}
}
yaz_log (b->log_freelist, "got block %d from freelist %d:%d", p->pos,
cat, p->pos/CAT_MAX);
memcpy (&b->file[cat].head.free_list, p->buf, sizeof(int));
}
p->cat = cat;
b->file[cat].head_dirty = 1;
memset (p->buf, 0, b->file[cat].head.block_size);
p->bytes = p->buf + ISAMB_DATA_OFFSET;
p->leaf = leaf;
p->size = 0;
p->dirty = 1;
p->deleted = 0;
p->offset = 0;
p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
return p;
}
struct ISAMB_block *new_leaf (ISAMB b, int cat)
{
return new_block (b, 1, cat);
}
struct ISAMB_block *new_int (ISAMB b, int cat)
{
return new_block (b, 0, cat);
}
static void check_block (ISAMB b, struct ISAMB_block *p)
{
if (p->leaf)
{
;
}
else
{
/* sanity check */
char *startp = p->bytes;
char *src = startp;
char *endp = p->bytes + p->size;
int pos;
decode_ptr (&src, &pos);
assert ((pos&CAT_MASK) == p->cat);
while (src != endp)
{
int item_len;
decode_ptr (&src, &item_len);
assert (item_len > 0 && item_len < 30);
src += item_len;
decode_ptr (&src, &pos);
assert ((pos&CAT_MASK) == p->cat);
}
}
}
void close_block (ISAMB b, struct ISAMB_block *p)
{
if (!p)
return;
if (p->deleted)
{
yaz_log (b->log_freelist, "release block %d from freelist %d:%d",
p->pos, p->cat, p->pos/CAT_MAX);
memcpy (p->buf, &b->file[p->cat].head.free_list, sizeof(int));
b->file[p->cat].head.free_list = p->pos;
if (!get_block (b, p->pos, p->buf, 1))
{
yaz_log (b->log_io, "bf_write: close_block (deleted)");
bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
}
}
else if (p->dirty)
{
int size = p->size + ISAMB_DATA_OFFSET;
assert (p->size >= 0);
p->buf[0] = p->leaf;
p->buf[1] = size & 255;
p->buf[2] = size >> 8;
check_block(b, p);
if (!get_block (b, p->pos, p->buf, 1))
{
yaz_log (b->log_io, "bf_write: close_block");
bf_write (b->file[p->cat].bf, p->pos/CAT_MAX, 0, 0, p->buf);
}
}
(*b->method->code_stop)(ISAMC_DECODE, p->decodeClientData);
xfree (p->buf);
xfree (p);
}
int insert_sub (ISAMB b, struct ISAMB_block **p,
void *new_item, int *mode,
ISAMC_I *stream,
struct ISAMB_block **sp,
void *sub_item, int *sub_size,
void *max_item);
int insert_int (ISAMB b, struct ISAMB_block *p, void *lookahead_item,
int *mode,
ISAMC_I *stream, struct ISAMB_block **sp,
void *split_item, int *split_size, void *last_max_item)
{
char *startp = p->bytes;
char *src = startp;
char *endp = p->bytes + p->size;
int pos;
struct ISAMB_block *sub_p1 = 0, *sub_p2 = 0;
char sub_item[DST_ITEM_MAX];
int sub_size;
int more = 0;
*sp = 0;
assert(p->size >= 0);
decode_ptr (&src, &pos);
while (src != endp)
{
int item_len;
int d;
char *src0 = src;
decode_ptr (&src, &item_len);
d = (*b->method->compare_item)(src, lookahead_item);
if (d > 0)
{
sub_p1 = open_block (b, pos);
assert (sub_p1);
more = insert_sub (b, &sub_p1, lookahead_item, mode,
stream, &sub_p2,
sub_item, &sub_size, src);
src = src0;
break;
}
src += item_len;
decode_ptr (&src, &pos);
}
if (!sub_p1)
{
sub_p1 = open_block (b, pos);
assert (sub_p1);
more = insert_sub (b, &sub_p1, lookahead_item, mode, stream, &sub_p2,
sub_item, &sub_size, last_max_item);
}
if (sub_p2)
{
/* there was a split - must insert pointer in this one */
char dst_buf[DST_BUF_SIZE];
char *dst = dst_buf;
assert (sub_size < 30 && sub_size > 1);
memcpy (dst, startp, src - startp);
dst += src - startp;
encode_ptr (&dst, sub_size); /* sub length and item */
memcpy (dst, sub_item, sub_size);
dst += sub_size;
encode_ptr (&dst, sub_p2->pos); /* pos */
if (endp - src) /* remaining data */
{
memcpy (dst, src, endp - src);
dst += endp - src;
}
p->size = dst - dst_buf;
assert (p->size >= 0);
if (p->size <= b->file[p->cat].head.block_max)
{
memcpy (startp, dst_buf, dst - dst_buf);
}
else
{
int p_new_size;
char *half;
src = dst_buf;
endp = dst;
half = src + b->file[p->cat].head.block_size/2;
decode_ptr (&src, &pos);
while (src <= half)
{
decode_ptr (&src, split_size);
src += *split_size;
decode_ptr (&src, &pos);
}
p_new_size = src - dst_buf;
memcpy (p->bytes, dst_buf, p_new_size);
decode_ptr (&src, split_size);
memcpy (split_item, src, *split_size);
src += *split_size;
*sp = new_int (b, p->cat);
(*sp)->size = endp - src;
memcpy ((*sp)->bytes, src, (*sp)->size);
p->size = p_new_size;
}
p->dirty = 1;
close_block (b, sub_p2);
}
close_block (b, sub_p1);
return more;
}
int insert_leaf (ISAMB b, struct ISAMB_block **sp1, void *lookahead_item,
int *lookahead_mode, ISAMC_I *stream,
struct ISAMB_block **sp2,
void *sub_item, int *sub_size,
void *max_item)
{
struct ISAMB_block *p = *sp1;
char *src = 0, *endp = 0;
char dst_buf[DST_BUF_SIZE], *dst = dst_buf;
int new_size;
void *c1 = (*b->method->code_start)(ISAMC_DECODE);
void *c2 = (*b->method->code_start)(ISAMC_ENCODE);
int more = 1;
int quater = b->file[b->no_cat-1].head.block_max / CAT_MAX;
char *cut = dst_buf + quater * 2;
char *maxp = dst_buf + b->file[b->no_cat-1].head.block_max;
char *half1 = 0;
char *half2 = 0;
char cut_item_buf[DST_ITEM_MAX];
int cut_item_size = 0;
if (p && p->size)
{
char file_item_buf[DST_ITEM_MAX];
char *file_item = file_item_buf;
src = p->bytes;
endp = p->bytes + p->size;
(*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
while (1)
{
char *dst_item = 0;
char *lookahead_next;
int d = -1;
if (lookahead_item)
d = (*b->method->compare_item)(file_item_buf, lookahead_item);
if (d > 0)
{
dst_item = lookahead_item;
if (!*lookahead_mode)
{
yaz_log (LOG_WARN, "isamb: Inconsistent register (1)");
assert (*lookahead_mode);
}
}
else
dst_item = file_item_buf;
if (!*lookahead_mode && d == 0)
{
p->dirty = 1;
}
else if (!half1 && dst > cut)
{
char *dst_item_0 = dst_item;
half1 = dst; /* candidate for splitting */
(*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
cut_item_size = dst_item - dst_item_0;
memcpy (cut_item_buf, dst_item_0, cut_item_size);
half2 = dst;
}
else
(*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
if (d > 0)
{
if (dst > maxp)
lookahead_item = 0;
else
{
lookahead_next = lookahead_item;
if (!(*stream->read_item)(stream->clientData,
&lookahead_next,
lookahead_mode))
{
lookahead_item = 0;
more = 0;
}
if (lookahead_item && max_item &&
(*b->method->compare_item)(max_item, lookahead_item) <= 0)
{
/* max_item 1 */
lookahead_item = 0;
}
p->dirty = 1;
}
}
else if (d == 0)
{
lookahead_next = lookahead_item;
if (!(*stream->read_item)(stream->clientData,
&lookahead_next, lookahead_mode))
{
lookahead_item = 0;
more = 0;
}
if (src == endp)
break;
file_item = file_item_buf;
(*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
}
else
{
if (src == endp)
break;
file_item = file_item_buf;
(*b->method->code_item)(ISAMC_DECODE, c1, &file_item, &src);
}
}
}
maxp = dst_buf + b->file[b->no_cat-1].head.block_max + quater;
while (lookahead_item)
{
char *dst_item = lookahead_item;
char *dst_0 = dst;
if (max_item &&
(*b->method->compare_item)(max_item, lookahead_item) <= 0)
{
/* max_item 2 */
break;
}
if (!*lookahead_mode)
{
yaz_log (LOG_WARN, "isamb: Inconsistent register (2)");
abort();
}
else if (!half1 && dst > cut)
{
char *dst_item_0 = dst_item;
half1 = dst; /* candidate for splitting */
(*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
cut_item_size = dst_item - dst_item_0;
memcpy (cut_item_buf, dst_item_0, cut_item_size);
half2 = dst;
}
else
(*b->method->code_item)(ISAMC_ENCODE, c2, &dst, &dst_item);
if (dst > maxp)
{
dst = dst_0;
break;
}
if (p)
p->dirty = 1;
dst_item = lookahead_item;
if (!(*stream->read_item)(stream->clientData, &dst_item,
lookahead_mode))
{
lookahead_item = 0;
more = 0;
}
}
new_size = dst - dst_buf;
if (p && p->cat != b->no_cat-1 &&
new_size > b->file[p->cat].head.block_max)
{
/* non-btree block will be removed */
p->deleted = 1;
close_block (b, p);
/* delete it too!! */
p = 0; /* make a new one anyway */
}
if (!p)
{ /* must create a new one */
int i;
for (i = 0; i < b->no_cat; i++)
if (new_size <= b->file[i].head.block_max)
break;
if (i == b->no_cat)
i = b->no_cat - 1;
p = new_leaf (b, i);
}
if (new_size > b->file[p->cat].head.block_max)
{
char *first_dst;
char *cut_item = cut_item_buf;
assert (half1);
assert (half2);
/* first half */
p->size = half1 - dst_buf;
memcpy (p->bytes, dst_buf, half1 - dst_buf);
/* second half */
*sp2 = new_leaf (b, p->cat);
(*b->method->code_reset)(c2);
first_dst = (*sp2)->bytes;
(*b->method->code_item)(ISAMC_ENCODE, c2, &first_dst, &cut_item);
memcpy (first_dst, half2, dst - half2);
(*sp2)->size = (first_dst - (*sp2)->bytes) + (dst - half2);
(*sp2)->dirty = 1;
p->dirty = 1;
memcpy (sub_item, cut_item_buf, cut_item_size);
*sub_size = cut_item_size;
}
else
{
memcpy (p->bytes, dst_buf, dst - dst_buf);
p->size = new_size;
}
(*b->method->code_stop)(ISAMC_DECODE, c1);
(*b->method->code_stop)(ISAMC_ENCODE, c2);
*sp1 = p;
return more;
}
int insert_sub (ISAMB b, struct ISAMB_block **p, void *new_item,
int *mode,
ISAMC_I *stream,
struct ISAMB_block **sp,
void *sub_item, int *sub_size,
void *max_item)
{
if (!*p || (*p)->leaf)
return insert_leaf (b, p, new_item, mode, stream, sp, sub_item,
sub_size, max_item);
else
return insert_int (b, *p, new_item, mode, stream, sp, sub_item,
sub_size, max_item);
}
int isamb_unlink (ISAMB b, ISAMC_P pos)
{
struct ISAMB_block *p1;
if (!pos)
return 0;
p1 = open_block(b, pos);
p1->deleted = 1;
if (!p1->leaf)
{
int sub_p;
int item_len;
char *src = p1->bytes + p1->offset;
decode_ptr(&src, &sub_p);
isamb_unlink(b, sub_p);
while (src != p1->bytes + p1->size)
{
decode_ptr(&src, &item_len);
src += item_len;
decode_ptr(&src, &sub_p);
isamb_unlink(b, sub_p);
}
}
close_block(b, p1);
return 0;
}
int isamb_merge (ISAMB b, ISAMC_P pos, ISAMC_I *stream)
{
char item_buf[DST_ITEM_MAX];
char *item_ptr;
int i_mode;
int more;
if (b->cache < 0)
{
int more = 1;
while (more)
{
item_ptr = item_buf;
more =
(*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
}
return 1;
}
item_ptr = item_buf;
more = (*stream->read_item)(stream->clientData, &item_ptr, &i_mode);
while (more)
{
struct ISAMB_block *p = 0, *sp = 0;
char sub_item[DST_ITEM_MAX];
int sub_size;
if (pos)
p = open_block (b, pos);
more = insert_sub (b, &p, item_buf, &i_mode, stream, &sp,
sub_item, &sub_size, 0);
if (sp)
{ /* increase level of tree by one */
struct ISAMB_block *p2 = new_int (b, p->cat);
char *dst = p2->bytes + p2->size;
encode_ptr (&dst, p->pos);
assert (sub_size < 20);
encode_ptr (&dst, sub_size);
memcpy (dst, sub_item, sub_size);
dst += sub_size;
encode_ptr (&dst, sp->pos);
p2->size = dst - p2->bytes;
pos = p2->pos; /* return new super page */
close_block (b, sp);
close_block (b, p2);
}
else
pos = p->pos; /* return current one (again) */
close_block (b, p);
}
return pos;
}
ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
{
ISAMB_PP pp = xmalloc (sizeof(*pp));
int i;
pp->isamb = isamb;
pp->block = xmalloc (ISAMB_MAX_LEVEL * sizeof(*pp->block));
pp->pos = pos;
pp->level = 0;
pp->maxlevel=0;
pp->total_size = 0;
pp->no_blocks = 0;
pp->skipped_numbers=0;
pp->returned_numbers=0;
for (i = 0; i<ISAMB_MAX_LEVEL; i++)
pp->skipped_nodes[i] = pp->accessed_nodes[i] = 0;
pp->block[0] = 0;
if (pos)
{
while (1)
{
struct ISAMB_block *p = open_block (isamb, pos);
char *src = p->bytes + p->offset;
pp->block[pp->level] = p;
pp->total_size += p->size;
pp->no_blocks++;
if (p->leaf)
break;
decode_ptr (&src, &pos);
p->offset = src - p->bytes;
pp->level++;
pp->accessed_nodes[pp->level]++;
}
}
pp->block[pp->level+1] = 0;
pp->maxlevel = pp->level;
if (level)
*level = pp->level;
return pp;
}
ISAMB_PP isamb_pp_open (ISAMB isamb, ISAMB_P pos)
{
return isamb_pp_open_x (isamb, pos, 0);
}
void isamb_pp_close_x (ISAMB_PP pp, int *size, int *blocks)
{
int i;
if (!pp)
return;
logf(LOG_DEBUG,"isamb_pp_close lev=%d returned %d values, skipped %d",
pp->maxlevel, pp->skipped_numbers, pp->returned_numbers);
for (i=pp->maxlevel;i>=0;i--)
if ( pp->skipped_nodes[i] || pp->accessed_nodes[i])
logf(LOG_DEBUG,"isamb_pp_close level leaf-%d: %d read, %d skipped", i,
pp->accessed_nodes[i], pp->skipped_nodes[i]);
pp->isamb->skipped_numbers += pp->skipped_numbers;
pp->isamb->returned_numbers += pp->returned_numbers;
for (i=pp->maxlevel;i>=0;i--)
{
pp->isamb->accessed_nodes[i] += pp->accessed_nodes[i];
pp->isamb->skipped_nodes[i] += pp->skipped_nodes[i];
}
if (size)
*size = pp->total_size;
if (blocks)
*blocks = pp->no_blocks;
for (i = 0; i <= pp->level; i++)
close_block (pp->isamb, pp->block[i]);
xfree (pp->block);
xfree (pp);
}
int isamb_block_info (ISAMB isamb, int cat)
{
if (cat >= 0 && cat < isamb->no_cat)
return isamb->file[cat].head.block_size;
return -1;
}
void isamb_pp_close (ISAMB_PP pp)
{
isamb_pp_close_x (pp, 0, 0);
}
/* simple recursive dumper .. */
static void isamb_dump_r (ISAMB b, ISAMB_P pos, void (*pr)(const char *str),
int level)
{
char buf[1024];
char prefix_str[1024];
if (pos)
{
struct ISAMB_block *p = open_block (b, pos);
sprintf(prefix_str, "%*s %d cat=%d size=%d max=%d", level*2, "",
pos, p->cat, p->size, b->file[p->cat].head.block_max);
(*pr)(prefix_str);
sprintf(prefix_str, "%*s %d", level*2, "", pos);
if (p->leaf)
{
while (p->offset < p->size)
{
char *src = p->bytes + p->offset;
char *dst = buf;
(*b->method->code_item)(ISAMC_DECODE, p->decodeClientData,
&dst, &src);
(*b->method->log_item)(LOG_DEBUG, buf, prefix_str);
p->offset = src - (char*) p->bytes;
}
assert(p->offset == p->size);
}
else
{
char *src = p->bytes + p->offset;
int sub;
int item_len;
decode_ptr (&src, &sub);
p->offset = src - (char*) p->bytes;
isamb_dump_r(b, sub, pr, level+1);
while (p->offset < p->size)
{
decode_ptr (&src, &item_len);
(*b->method->log_item)(LOG_DEBUG, src, prefix_str);
src += item_len;
decode_ptr (&src, &sub);
p->offset = src - (char*) p->bytes;
isamb_dump_r(b, sub, pr, level+1);
}
}
close_block(b,p);
}
}
void isamb_dump (ISAMB b, ISAMB_P pos, void (*pr)(const char *str))
{
isamb_dump_r(b, pos, pr, 0);
}
#if 0
/* Old isamb_pp_read that Adam wrote, kept as a reference in case we need to
debug the more complex pp_read that also forwards. May be deleted near end
of 2004, if it has not shown to be useful */
int isamb_pp_read (ISAMB_PP pp, void *buf)
{
char *dst = buf;
char *src;
struct ISAMB_block *p = pp->block[pp->level];
if (!p)
return 0;
while (p->offset == p->size)
{
int pos, item_len;
while (p->offset == p->size)
{
if (pp->level == 0)
return 0;
close_block (pp->isamb, pp->block[pp->level]);
pp->block[pp->level] = 0;
(pp->level)--;
p = pp->block[pp->level];
assert (!p->leaf);
}
src = p->bytes + p->offset;
decode_ptr (&src, &item_len);
src += item_len;
decode_ptr (&src, &pos);
p->offset = src - (char*) p->bytes;
++(pp->level);
while (1)
{
pp->block[pp->level] = p = open_block (pp->isamb, pos);
pp->total_size += p->size;
pp->no_blocks++;
if (p->leaf)
{
break;
}
src = p->bytes + p->offset;
decode_ptr (&src, &pos);
p->offset = src - (char*) p->bytes;
pp->level++;
}
}
assert (p->offset < p->size);
assert (p->leaf);
src = p->bytes + p->offset;
(*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
&dst, &src);
p->offset = src - (char*) p->bytes;
/* key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1"); */
return 1;
}
#else
int isamb_pp_read (ISAMB_PP pp, void *buf)
{
return isamb_pp_forward(pp,buf,0);
}
#endif
#define NEW_FORWARD 1
#if NEW_FORWARD == 1
/*
#undef ISAMB_DEBUB
#define ISAMB_DEBUG 1
*/
static int isamb_pp_on_right_node(ISAMB_PP pp, int level, const void *untilbuf)
{ /* looks one node higher to see if we should be on this node at all */
/* useful in backing off quickly, and in avoiding tail descends */
/* call with pp->level to begin with */
struct ISAMB_block *p;
int cmp;
char *src;
int item_len;
assert(level>=0);
if ( level == 0) {
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_on_right returning true for root");
#endif
return 1; /* we can never skip the root node */
}
level--;
p=pp->block[level];
assert(p->offset <= p->size);
if (p->offset < p->size )
{
assert(p->offset>0);
src=p->bytes + p->offset;
decode_ptr(&src,&item_len);
#if ISAMB_DEBUG
(*pp->isamb->method->log_item)(LOG_DEBUG,untilbuf,"on_leaf: until");
(*pp->isamb->method->log_item)(LOG_DEBUG,src,"on_leaf: value");
#endif
cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
if (cmp<2) {
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_on_right returning true "
"cmp=%d lev=%d ofs=%d",cmp,level,p->offset);
#endif
return 1;
}
else {
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_on_right returning false "
"cmp=%d lev=%d ofs=%d",cmp,level,p->offset);
#endif
return 0;
}
}
else {
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_on_right at tail, looking higher "
"lev=%d",level);
#endif
return isamb_pp_on_right_node(pp, level, untilbuf);
}
} /* isamb_pp_on_right_node */
static int isamb_pp_read_on_leaf(ISAMB_PP pp, void *buf)
{ /* reads the next item on the current leaf, returns 0 if end of leaf*/
struct ISAMB_block *p = pp->block[pp->level];
char *dst;
char *src;
assert(pp);
assert(buf);
if (!p || p->offset == p->size) {
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_read_on_leaf returning 0 on node %d",p->pos);
#endif
return 0; /* at end of leaf */
}
src=p->bytes + p->offset;
dst=buf;
(*pp->isamb->method->code_item)
(ISAMC_DECODE, p->decodeClientData,&dst, &src);
p->offset = src - (char*) p->bytes;
/*
#if ISAMB_DEBUG
(*pp->isamb->method->log_item)(LOG_DEBUG, buf, "read_on_leaf returning 1");
#endif
*/
return 1;
} /* read_on_leaf */
static int isamb_pp_forward_on_leaf(ISAMB_PP pp, void *buf, const void *untilbuf)
{ /* forwards on the current leaf, returns 0 if not found */
int cmp;
int skips=0;
while (1){
if (!isamb_pp_read_on_leaf(pp,buf))
return 0;
/* FIXME - this is an extra function call, inline the read? */
cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
if (cmp <2){ /* found a good one */
#if ISAMB_DEBUG
if (skips)
logf(LOG_DEBUG, "isam_pp_fwd_on_leaf skipped %d items",skips);
#endif
pp->returned_numbers++;
return 1;
}
if (!skips)
if (!isamb_pp_on_right_node(pp, pp->level, untilbuf))
return 0; /* never mind the rest of this leaf */
pp->skipped_numbers++;
skips++;
}
} /* forward_on_leaf */
static int isamb_pp_climb_level(ISAMB_PP pp, int *pos)
{ /* climbs higher in the tree, until finds a level with data left */
/* returns the node to (consider to) descend to in *pos) */
struct ISAMB_block *p = pp->block[pp->level];
char *src;
int item_len;
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_climb_level starting "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
assert(pp->level >= 0);
if (!p)
return 0;
assert(p->offset <= p->size);
if (pp->level==0)
{
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_climb_level returning 0 at root");
#endif
return 0;
}
assert(pp->level>0);
close_block(pp->isamb, pp->block[pp->level]);
pp->block[pp->level]=0;
(pp->level)--;
p=pp->block[pp->level];
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_climb_level climbed to level %d node %d ofs=%d",
pp->level, p->pos, p->offset);
#endif
assert(!p->leaf);
assert(p->offset <= p->size);
if (p->offset == p->size ) {
/* we came from the last pointer, climb on */
if (!isamb_pp_climb_level(pp,pos))
return 0;
p=pp->block[pp->level];
}
else
{
/* skip the child we just came from */
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isam_pp_climb_level: skipping lev=%d ofs=%d sz=%d",
pp->level, p->offset, p->size);
#endif
assert (p->offset < p->size );
src=p->bytes + p->offset;
decode_ptr(&src, &item_len);
src += item_len;
decode_ptr(&src, pos);
p->offset=src - (char *)p->bytes;
}
return 1;
} /* climb_level */
static int isamb_pp_forward_unode(ISAMB_PP pp, int pos, const void *untilbuf)
{ /* scans a upper node until it finds a child <= untilbuf */
/* pp points to the key value, as always. pos is the child read from */
/* the buffer */
/* if all values are too small, returns the last child in the node */
/* FIXME - this can be detected, and avoided by looking at the */
/* parent node, but that gets messy. Presumably the cost is */
/* pretty low anyway */
struct ISAMB_block *p = pp->block[pp->level];
char *src = p->bytes + p->offset;
int item_len;
int cmp;
int nxtpos;
#if ISAMB_DEBUG
int skips = 0;
if (p)
logf(LOG_DEBUG,"isamb_pp_forward_unode starting "
"at level %d node %d ofs=%di sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
assert(!p->leaf);
assert(p->offset <= p->size);
if (p->offset == p->size) {
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward_unode returning at end "
"at level %d node %d ofs=%di sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return pos; /* already at the end of it */
}
while(p->offset < p->size)
{
decode_ptr(&src,&item_len);
cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
src+=item_len;
decode_ptr(&src,&nxtpos);
if (cmp<2)
{
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward_unode returning a hit "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return pos;
} /* found one */
pos=nxtpos;
p->offset=src-(char*)p->bytes;
(pp->skipped_nodes[pp->maxlevel - pp->level -1])++;
#if ISAMB_DEBUG
skips++;
#endif
}
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward_unode returning at tail "
"at level %d node %d ofs=%d sz=%d skips=%d",
pp->level, p->pos, p->offset, p->size, skips);
#endif
return pos; /* that's the last one in the line */
} /* forward_unode */
static void isamb_pp_descend_to_leaf(ISAMB_PP pp, int pos, const void *untilbuf)
{ /* climbs down the tree, from pos, to the leftmost leaf */
struct ISAMB_block *p = pp->block[pp->level];
char *src;
assert(!p->leaf);
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_descend_to_leaf "
"starting at lev %d node %d ofs=%d lf=%d u=%p",
pp->level, p->pos, p->offset, p->leaf, untilbuf);
#endif
if (untilbuf)
pos=isamb_pp_forward_unode(pp,pos,untilbuf);
++(pp->level);
assert(pos);
p = open_block(pp->isamb, pos);
pp->block[pp->level] = p;
++(pp->accessed_nodes[pp->maxlevel-pp->level]);
++(pp->no_blocks);
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_descend_to_leaf "
"got lev %d node %d lf=%d",
pp->level, p->pos, p->leaf);
#endif
if (p->leaf)
return;
assert (p->offset==0);
src = p->bytes + p->offset;
decode_ptr(&src, &pos);
p->offset = src-(char*)p->bytes;
isamb_pp_descend_to_leaf(pp,pos,untilbuf);
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_descend_to_leaf "
"returning at lev %d node %d ofs=%d lf=%d",
pp->level, p->pos, p->offset, p->leaf);
#endif
} /* descend_to_leaf */
static int isamb_pp_find_next_leaf(ISAMB_PP pp)
{ /* finds the next leaf by climbing up and down */
int pos;
if (!isamb_pp_climb_level(pp,&pos))
return 0;
isamb_pp_descend_to_leaf(pp, pos,0);
return 1;
}
static int isamb_pp_climb_desc(ISAMB_PP pp, void *buf, const void *untilbuf)
{ /* climbs up and descends to a leaf where values >= *untilbuf are found */
int pos;
#if ISAMB_DEBUG
struct ISAMB_block *p = pp->block[pp->level];
logf(LOG_DEBUG,"isamb_pp_climb_desc starting "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
if (!isamb_pp_climb_level(pp,&pos))
return 0;
/* see if it would pay to climb one higher */
if (!isamb_pp_on_right_node(pp, pp->level, untilbuf))
if (!isamb_pp_climb_level(pp,&pos))
return 0;
isamb_pp_descend_to_leaf(pp, pos,untilbuf);
#if ISAMB_DEBUG
p = pp->block[pp->level];
logf(LOG_DEBUG,"isamb_pp_climb_desc done "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return 1;
} /* climb_desc */
int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
{
#if ISAMB_DEBUG
struct ISAMB_block *p = pp->block[pp->level];
if (p)
{
assert(p->leaf);
logf(LOG_DEBUG,"isamb_pp_forward starting "
"at level %d node %d ofs=%d sz=%d u=%p",
pp->level, p->pos, p->offset, p->size,untilbuf);
}
#endif
if (untilbuf) {
if (isamb_pp_forward_on_leaf( pp, buf, untilbuf)) {
#if ISAMB_DEBUG
if (p)
logf(LOG_DEBUG,"isamb_pp_forward (f) returning (A) "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return 1;
}
if (! isamb_pp_climb_desc( pp, buf, untilbuf)) {
#if ISAMB_DEBUG
if (p)
logf(LOG_DEBUG,"isamb_pp_forward (f) returning notfound (B) "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return 0; /* could not find a leaf */
}
do {
if (isamb_pp_forward_on_leaf( pp, buf, untilbuf)) {
#if ISAMB_DEBUG
if(p)
logf(LOG_DEBUG,"isamb_pp_forward (f) returning (C) "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return 1;
}
} while (isamb_pp_find_next_leaf(pp));
return 0; /* could not find at all */
}
else { /* no untilbuf, a straight read */
/* FIXME - this should be moved
* directly into the pp_read */
/* keeping here now, to keep same
* interface as the old fwd */
if (isamb_pp_read_on_leaf( pp, buf)) {
#if ISAMB_DEBUG
if (p)
logf(LOG_DEBUG,"isamb_pp_forward (read) returning (D) "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return 1;
}
if (isamb_pp_find_next_leaf(pp)) {
#if ISAMB_DEBUG
if (p)
logf(LOG_DEBUG,"isamb_pp_forward (read) returning (E) "
"at level %d node %d ofs=%d sz=%d",
pp->level, p->pos, p->offset, p->size);
#endif
return isamb_pp_read_on_leaf(pp, buf);
}
else
return 0;
}
} /* isam_pp_forward (new version) */
#elif NEW_FORWARD == 0
int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
{
/* pseudocode:
* while 1
* while at end of node
* climb higher. If out, return 0
* while not on a leaf (and not at its end)
* decode next
* if cmp
* descend to node
* decode next
* if cmp
* return 1
*/
/*
* The upper nodes consist of a sequence of nodenumbers and keys
* When opening a block, the first node number is read in, and
* offset points to the first key, which is the upper limit of keys
* in the node just read.
*/
char *dst = buf;
char *src;
struct ISAMB_block *p = pp->block[pp->level];
int cmp;
int item_len;
int pos;
int nxtpos;
int descending=0; /* used to prevent a border condition error */
if (!p)
return 0;
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward starting [%p] p=%d",pp,p->pos);
(*pp->isamb->method->log_item)(LOG_DEBUG, untilbuf, "until");
(*pp->isamb->method->log_item)(LOG_DEBUG, buf, "buf");
#endif
while (1)
{
while ( (p->offset == p->size) && !descending )
{ /* end of this block - climb higher */
assert (p->offset <= p->size);
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward climbing from l=%d",
pp->level);
#endif
if (pp->level == 0)
{
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward returning 0 at root");
#endif
return 0; /* at end of the root, nothing left */
}
close_block(pp->isamb, pp->block[pp->level]);
pp->block[pp->level]=0;
(pp->level)--;
p=pp->block[pp->level];
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward climbed to node %d off=%d",
p->pos, p->offset);
#endif
assert(!p->leaf);
assert(p->offset <= p->size);
/* skip the child we have handled */
if (p->offset != p->size)
{
src = p->bytes + p->offset;
decode_ptr(&src, &item_len);
#if ISAMB_DEBUG
(*pp->isamb->method->log_item)(LOG_DEBUG, src,
" isamb_pp_forward "
"climb skipping old key");
#endif
src += item_len;
decode_ptr(&src,&pos);
p->offset = src - (char*) p->bytes;
break; /* even if this puts us at the end of the block, we
need to descend to the last pos. UGLY coding,
clean up some day */
}
}
if (!p->leaf)
{
src = p->bytes + p->offset;
if (p->offset == p->size)
cmp=-2 ; /* descend to the last node, as we have
no value to cmp */
else
{
decode_ptr(&src, &item_len);
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward (B) on a high node. "
"ofs=%d sz=%d nxtpos=%d ",
p->offset,p->size,pos);
(*pp->isamb->method->log_item)(LOG_DEBUG, src, "");
#endif
if (untilbuf)
cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
else
cmp=-2;
src += item_len;
decode_ptr(&src,&nxtpos);
}
if (cmp<2)
{
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isambb_pp_forward descending l=%d p=%d ",
pp->level, pos);
#endif
descending=1; /* prevent climbing for a while */
++(pp->level);
p = open_block(pp->isamb,pos);
pp->block[pp->level] = p ;
pp->total_size += p->size;
(pp->accessed_nodes[pp->maxlevel - pp->level])++;
pp->no_blocks++;
if ( !p->leaf)
{ /* block starts with a pos */
src = p->bytes + p->offset;
decode_ptr(&src,&pos);
p->offset=src-(char*) p->bytes;
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward: block %d starts with %d",
p->pos, pos);
#endif
}
} /* descend to the node */
else
{ /* skip the node */
p->offset = src - (char*) p->bytes;
pos=nxtpos;
(pp->skipped_nodes[pp->maxlevel - pp->level -1])++;
#if ISAMB_DEBUG
logf(LOG_DEBUG,
"isamb_pp_forward: skipping block on level %d, noting "
"on %d (%d)",
pp->level, pp->maxlevel - pp->level-1 ,
pp->skipped_nodes[pp->maxlevel - pp->level-1 ]);
#endif
/* 0 is always leafs, 1 is one level above leafs etc, no
* matter how high tree */
}
} /* not on a leaf */
else
{ /* on a leaf */
if (p->offset == p->size) {
descending = 0;
}
else
{
assert (p->offset < p->size);
src = p->bytes + p->offset;
dst=buf;
(*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
&dst, &src);
p->offset = src - (char*) p->bytes;
if (untilbuf)
cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
else
cmp=-2;
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward on a leaf. cmp=%d",
cmp);
(*pp->isamb->method->log_item)(LOG_DEBUG, buf, "");
#endif
if (cmp <2)
{
#if ISAMB_DEBUG
if (untilbuf)
{
(*pp->isamb->method->log_item)(
LOG_DEBUG, buf, "isamb_pp_forward returning 1");
}
else
{
(*pp->isamb->method->log_item)(
LOG_DEBUG, buf, "isamb_pp_read returning 1 (fwd)");
}
#endif
pp->returned_numbers++;
return 1;
}
else
pp->skipped_numbers++;
}
} /* leaf */
} /* main loop */
}
#elif NEW_FORWARD == 2
int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilb)
{
char *dst = buf;
char *src;
struct ISAMB_block *p = pp->block[pp->level];
if (!p)
return 0;
again:
while (p->offset == p->size)
{
int pos, item_len;
while (p->offset == p->size)
{
if (pp->level == 0)
return 0;
close_block (pp->isamb, pp->block[pp->level]);
pp->block[pp->level] = 0;
(pp->level)--;
p = pp->block[pp->level];
assert (!p->leaf);
}
assert(!p->leaf);
src = p->bytes + p->offset;
decode_ptr (&src, &item_len);
src += item_len;
decode_ptr (&src, &pos);
p->offset = src - (char*) p->bytes;
src = p->bytes + p->offset;
while(1)
{
if (!untilb || p->offset == p->size)
break;
assert(p->offset < p->size);
decode_ptr (&src, &item_len);
if ((*pp->isamb->method->compare_item)(untilb, src) <= 1)
break;
src += item_len;
decode_ptr (&src, &pos);
p->offset = src - (char*) p->bytes;
}
pp->level++;
while (1)
{
pp->block[pp->level] = p = open_block (pp->isamb, pos);
pp->total_size += p->size;
pp->no_blocks++;
if (p->leaf)
{
break;
}
src = p->bytes + p->offset;
while(1)
{
decode_ptr (&src, &pos);
p->offset = src - (char*) p->bytes;
if (!untilb || p->offset == p->size)
break;
assert(p->offset < p->size);
decode_ptr (&src, &item_len);
if ((*pp->isamb->method->compare_item)(untilb, src) <= 1)
break;
src += item_len;
}
pp->level++;
}
}
assert (p->offset < p->size);
assert (p->leaf);
while(1)
{
char *dst0 = dst;
src = p->bytes + p->offset;
(*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
&dst, &src);
p->offset = src - (char*) p->bytes;
if (!untilb || (*pp->isamb->method->compare_item)(untilb, dst0) <= 1)
break;
dst = dst0;
if (p->offset == p->size) goto again;
}
/* key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1"); */
return 1;
}
#endif
int isamb_pp_num (ISAMB_PP pp)
{
return 1;
}
static void isamb_pp_leaf_pos( ISAMB_PP pp,
int *current, int *total, void *dummybuf )
{
struct ISAMB_block *p = pp->block[pp->level];
char *src=p->bytes;
char *end=p->bytes+p->size;
char *cur=p->bytes+p->offset;
char *dst;
assert(p->offset <= p->size);
assert(cur <= end);
assert(p->leaf);
*current=0;
*total=0;
while(src < end) {
dst=dummybuf;
(*pp->isamb->method->code_item)
(ISAMC_DECODE, p->decodeClientData,&dst, &src);
assert(dst<(char*) dummybuf+100); /*FIXME */
(*total)++;
if (src<=cur)
(*current)++;
}
logf(LOG_DEBUG, "isamb_pp_leaf_pos: cur=%d tot=%d ofs=%d sz=%d lev=%d",
*current, *total, p->offset, p->size, pp->level);
assert(src==end);
}
static void isamb_pp_upper_pos( ISAMB_PP pp, int *current, int *total,
int size, int level )
{ /* estimates total/current occurrences from here up, excl leaf */
struct ISAMB_block *p = pp->block[level];
char *src=p->bytes;
char *end=p->bytes+p->size;
char *cur=p->bytes+p->offset;
int item_size;
int child;
assert(level>=0);
assert(!p->leaf);
logf(LOG_DEBUG,"isamb_pp_upper_pos at beginning l=%d "
"cur=%d tot=%d ofs=%d sz=%d pos=%d",
level, *current, *total, p->offset, p->size, p->pos);
assert (p->offset <= p->size);
decode_ptr (&src, &child ); /* first child */
while(src < end) {
if (src!=cur) {
*total += size;
if (src < cur)
*current +=size;
}
decode_ptr (&src, &item_size );
assert(src+item_size<=end);
src += item_size;
decode_ptr (&src, &child );
}
if (level>0)
isamb_pp_upper_pos(pp, current, total, *total, level-1);
} /* upper_pos */
void isamb_pp_pos( ISAMB_PP pp, int *current, int *total )
{ /* return an estimate of the current position and of the total number of */
/* occureences in the isam tree, based on the current leaf */
struct ISAMB_block *p = pp->block[pp->level];
char dummy[100]; /* 100 bytes/entry must be enough */
assert(total);
assert(current);
assert(p->leaf);
isamb_pp_leaf_pos(pp,current, total, dummy);
if (pp->level>0)
isamb_pp_upper_pos(pp, current, total, *total, pp->level-1);
/*
logf(LOG_DEBUG,"isamb_pp_pos: C=%d T=%d =%6.2f%%",
*current, *total, 100.0*(*current)/(*total));
*/
}
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