static int64_t skip_cb(struct archive *arch, void *priv, int64_t request)
{
struct mp_archive_volume *vol = priv;
if (!volume_seek(vol))
return -1;
int64_t old = stream_tell(vol->src);
stream_skip(vol->src, request);
return stream_tell(vol->src) - old;
}
static ssize_t read_cb(struct archive *arch, void *priv, const void **buffer)
{
struct mp_archive_volume *vol = priv;
if (!volume_seek(vol))
return -1;
int res = stream_read_partial(vol->src, vol->mpa->buffer,
sizeof(vol->mpa->buffer));
*buffer = vol->mpa->buffer;
return MPMAX(res, 0);
}
u32 volume_write(volh handle, u32 sector, u32 count, void *data) {
voldata *vh = (voldata*)handle;
DWORD written;
void *buffer;
if (!count) return 0;
if (!volume_seek(handle, sector)) return 0;
buffer = VirtualAlloc(0, count*vh->ssize, MEM_COMMIT, PAGE_READWRITE);
memcpy(buffer, data, count*vh->ssize);
if (!WriteFile(vh->dh, buffer, count*vh->ssize, &written,0)) {
written = 0;
vh->pos = 0xFFFF;
} else
vh->pos+= written/vh->ssize;
VirtualFree(buffer, 0, MEM_RELEASE);
return written/vh->ssize;
}
u32 volume_read (volh handle, u32 sector, u32 count, void *data) {
voldata *vh = (voldata*)handle;
DWORD readed;
void *buffer;
if (!count) return 0;
if (!volume_seek(handle, sector)) return 0;
buffer = VirtualAlloc(0, count*vh->ssize, MEM_COMMIT, PAGE_READWRITE);
if (!ReadFile(vh->dh, buffer, count*vh->ssize, &readed,0)) {
readed = 0;
vh->pos = 0xFFFF;
} else {
memcpy(data, buffer, readed);
vh->pos+= readed/vh->ssize;
}
VirtualFree(buffer, 0, MEM_RELEASE);
return readed/vh->ssize;
}
