+static unsigned char *deflate_it(char *data,
+ unsigned long size,
+ unsigned long *result_size)
+{
+ int bound;
+ unsigned char *deflated;
+ z_stream stream;
+
+ memset(&stream, 0, sizeof(stream));
+ deflateInit(&stream, Z_BEST_COMPRESSION);
+ bound = deflateBound(&stream, size);
+ deflated = xmalloc(bound);
+ stream.next_out = deflated;
+ stream.avail_out = bound;
+
+ stream.next_in = (unsigned char *)data;
+ stream.avail_in = size;
+ while (deflate(&stream, Z_FINISH) == Z_OK)
+ ; /* nothing */
+ deflateEnd(&stream);
+ *result_size = stream.total_out;
+ return deflated;
+}
+
+static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
+{
+ void *cp;
+ void *delta;
+ void *deflated;
+ void *data;
+ unsigned long orig_size;
+ unsigned long delta_size;
+ unsigned long deflate_size;
+ unsigned long data_size;
+
+ printf("GIT binary patch\n");
+ /* We could do deflated delta, or we could do just deflated two,
+ * whichever is smaller.
+ */
+ delta = NULL;
+ deflated = deflate_it(two->ptr, two->size, &deflate_size);
+ if (one->size && two->size) {
+ delta = diff_delta(one->ptr, one->size,
+ two->ptr, two->size,
+ &delta_size, deflate_size);
+ if (delta) {
+ void *to_free = delta;
+ orig_size = delta_size;
+ delta = deflate_it(delta, delta_size, &delta_size);
+ free(to_free);
+ }
+ }
+
+ if (delta && delta_size < deflate_size) {
+ printf("delta %lu\n", orig_size);
+ free(deflated);
+ data = delta;
+ data_size = delta_size;
+ }
+ else {
+ printf("literal %lu\n", two->size);
+ free(delta);
+ data = deflated;
+ data_size = deflate_size;
+ }
+
+ /* emit data encoded in base85 */
+ cp = data;
+ while (data_size) {
+ int bytes = (52 < data_size) ? 52 : data_size;
+ char line[70];
+ data_size -= bytes;
+ if (bytes <= 26)
+ line[0] = bytes + 'A' - 1;
+ else
+ line[0] = bytes - 26 + 'a' - 1;
+ encode_85(line + 1, cp, bytes);
+ cp += bytes;
+ puts(line);
+ }
+ printf("\n");
+ free(data);
+}
+