void
InStream_seek(InStream *self, int64_t target) {
InStreamIVARS *const ivars = InStream_IVARS(self);
FileWindow *const window = ivars->window;
char *fw_buf = FileWindow_Get_Buf(window);
int64_t fw_offset = FileWindow_Get_Offset(window);
int64_t fw_len = FileWindow_Get_Len(window);
int64_t virtual_window_top = fw_offset - ivars->offset;
int64_t virtual_window_end = virtual_window_top + fw_len;
if (target < 0) {
THROW(ERR, "Can't Seek '%o' to negative target %i64", ivars->filename,
target);
}
// Seek within window if possible.
else if (target >= virtual_window_top
&& target <= virtual_window_end
) {
ivars->buf = fw_buf - fw_offset + ivars->offset + target;
}
else if (target > ivars->len) {
THROW(ERR, "Can't Seek '%o' past EOF (%i64 > %i64)", ivars->filename,
target, ivars->len);
}
else {
// Target is outside window. Set all buffer and limit variables to
// NULL to trigger refill on the next read. Store the file position
// in the FileWindow's offset.
FH_Release_Window(ivars->file_handle, window);
ivars->buf = NULL;
ivars->limit = NULL;
FileWindow_Set_Offset(window, ivars->offset + target);
}
}
void
InStream_seek(InStream *self, int64_t target) {
FileWindow *const window = self->window;
int64_t virtual_window_top = window->offset - self->offset;
int64_t virtual_window_end = virtual_window_top + window->len;
if (target < 0) {
THROW(ERR, "Can't Seek '%o' to negative target %i64", self->filename,
target);
}
// Seek within window if possible.
else if (target >= virtual_window_top
&& target <= virtual_window_end
) {
self->buf = window->buf - window->offset + self->offset + target;
}
else if (target > self->len) {
THROW(ERR, "Can't Seek '%o' past EOF (%i64 > %i64)", self->filename,
target, self->len);
}
else {
// Target is outside window. Set all buffer and limit variables to
// NULL to trigger refill on the next read. Store the file position
// in the FileWindow's offset.
FH_Release_Window(self->file_handle, window);
self->buf = NULL;
self->limit = NULL;
FileWindow_Set_Offset(window, self->offset + target);
}
}