Mirror of :pserver:cvs@cvs.fefe.de:/cvs libowfat https://www.fefe.de/libowfat/
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#define _FILE_OFFSET_BITS 64
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include "byte.h"
#include "cdb.h"
#include "havepread.h"
#ifdef __MINGW32__
#include "windows.h"
#else
#include <sys/mman.h>
#endif
void cdb_free(struct cdb *c) {
if (c->map) {
#ifdef __MINGW32__
UnmapViewOfFile(c->map);
#else
munmap(c->map,c->size);
#endif
c->map = 0;
}
}
void cdb_findstart(struct cdb *c) {
c->loop = 0;
}
void cdb_init(struct cdb *c,int64 fd) {
#ifndef __MINGW32__
struct stat st;
char *x;
#endif
cdb_free(c);
cdb_findstart(c);
c->fd = fd;
#ifdef __MINGW32__
{
HANDLE m=CreateFileMapping((HANDLE)(uintptr_t)fd,0,PAGE_READONLY,0,0,NULL);
if (m)
if ((c->map=MapViewOfFile(m,FILE_MAP_READ,0,0,0)))
c->size=GetFileSize((HANDLE)(uintptr_t)fd,NULL);
CloseHandle(m);
}
#else
if (fstat(fd,&st) == 0)
if (st.st_size <= 0xffffffff) {
x = mmap(0,st.st_size,PROT_READ,MAP_SHARED,fd,0);
if (x != MAP_FAILED) {
c->size = st.st_size;
c->map = x;
}
}
#endif
}
int cdb_read(struct cdb *c, unsigned char *buf, size_t len, uint32 pos) {
if (c->map) {
if ((pos > c->size) || (c->size - pos < len)) goto FORMAT;
byte_copy(buf,len,c->map + pos);
}
else {
#ifndef HAVE_PREAD
if (lseek(c->fd,pos,SEEK_SET) == -1) return -1;
#endif
while (len > 0) {
ssize_t r;
do
#ifdef HAVE_PREAD
r = pread(c->fd,buf,len,pos);
#else
r = read(c->fd,buf,len);
#endif
while ((r == -1) && (errno == EINTR));
if (r == -1) return -1;
if (r == 0) goto FORMAT;
buf += r;
len -= r;
#ifdef HAVE_PREAD
pos += r;
#endif
}
}
return 0;
FORMAT:
#ifdef EPROTO
errno = EPROTO;
#else
errno = EINVAL;
#endif
return -1;
}
static int match(struct cdb * restrict c, const unsigned char * restrict key, size_t len, uint32 pos) {
unsigned char buf[32];
unsigned long n;
while (len > 0) {
n = sizeof buf;
if (n > len) n = len;
if (cdb_read(c,buf,n,pos) == -1) return -1;
if (byte_diff(buf,n,key)) return 0;
pos += n;
key += n;
len -= n;
}
return 1;
}
int cdb_findnext(struct cdb *c, const unsigned char *key, size_t len) {
unsigned char buf[8];
uint32 pos;
uint32 u;
if (!c->loop) {
u = cdb_hash(key,len);
if (cdb_read(c,buf,8,(u << 3) & 2047) == -1) return -1;
uint32_unpack((char*)buf + 4,&c->hslots);
if (!c->hslots) return 0;
uint32_unpack((char*)buf,&c->hpos);
c->khash = u;
u >>= 8;
u %= c->hslots;
u <<= 3;
c->kpos = c->hpos + u;
}
while (c->loop < c->hslots) {
if (cdb_read(c,buf,8,c->kpos) == -1) return -1;
uint32_unpack((char*)buf + 4,&pos);
if (!pos) return 0;
c->loop += 1;
c->kpos += 8;
if (c->kpos == c->hpos + (c->hslots << 3)) c->kpos = c->hpos;
uint32_unpack((char*)buf,&u);
if (u == c->khash) {
if (cdb_read(c,buf,8,pos) == -1) return -1;
uint32_unpack((char*)buf,&u);
if (u == len)
switch(match(c,key,len,pos + 8)) {
case -1:
return -1;
case 1:
uint32_unpack((char*)buf + 4,&c->dlen);
c->dpos = pos + 8 + len;
return 1;
}
}
}
return 0;
}
int cdb_find(struct cdb *c, const unsigned char *key, size_t len) {
cdb_findstart(c);
return cdb_findnext(c,key,len);
}