static int read_int(int fd, int64_t *out, size_t size)
{
uint8_t tmp8 = 0;
uint16_t tmp16;
uint32_t tmp32;
uint64_t tmp64;
if (read(fd, &tmp64, size) == -1)
return -errno;
(void)tmp8;
switch (size)
{
case 1:
*out = *((int8_t *)(&tmp64));
break;
case 2:
tmp16 = betoht16(tmp64);
*out = *((int16_t *)(&tmp16));
break;
case 4:
tmp32 = betoht32(tmp64);
*out = *((int32_t *)(&tmp32));
break;
case 8:
tmp64 = betoht64(tmp64);
*out = *((int64_t *)(&tmp64));
break;
}
return 0;
}
int libretrodb_open(const char *path, libretrodb_t *db)
{
libretrodb_header_t header;
libretrodb_metadata_t md;
int rv;
int fd = open(path, O_RDWR);
if (fd == -1)
return -errno;
strcpy(db->path, path);
db->root = lseek(fd, 0, SEEK_CUR);
if ((rv = read(fd, &header, sizeof(header))) == -1)
{
rv = -errno;
goto error;
}
if (strncmp(header.magic_number, MAGIC_NUMBER, sizeof(MAGIC_NUMBER)) != 0)
{
rv = -EINVAL;
goto error;
}
header.metadata_offset = betoht64(header.metadata_offset);
lseek(fd, header.metadata_offset, SEEK_SET);
if (libretrodb_read_metadata(fd, &md) < 0)
{
rv = -EINVAL;
goto error;
}
db->count = md.count;
db->first_index_offset = lseek(fd, 0, SEEK_CUR);
db->fd = fd;
return 0;
error:
close(fd);
return rv;
}
static int read_uint(int fd, uint64_t *out, size_t size)
{
uint64_t tmp;
if (read(fd, &tmp, size) == -1)
return -errno;
switch (size)
{
case 1:
*out = *(uint8_t *)(&tmp);
break;
case 2:
*out = betoht16(tmp);
break;
case 4:
*out = betoht32(tmp);
break;
case 8:
*out = betoht64(tmp);
break;
}
return 0;
}
