+/* Memory allocation/freeing routines, called by zlib stuff. */
+static void *
+z_alloc(void *opaque, uInt items, uInt size)
+{
+ return malloc(items * size);
+}
+
+static void
+z_free(void *opaque, void *adrs, uInt nbytes)
+{
+ free(adrs);
+}
+
+/* Flag bytes in compressed stream are encoded as follows: */
+#define END_FLAG 0 /* that's all folks */
+#define TOKEN_LONG 0x20 /* followed by 32-bit token number */
+#define TOKENRUN_LONG 0x21 /* ditto with 16-bit run count */
+#define DEFLATED_DATA 0x40 /* + 6-bit high len, then low len byte */
+#define TOKEN_REL 0x80 /* + 6-bit relative token number */
+#define TOKENRUN_REL 0xc0 /* ditto with 16-bit run count */
+
+#define MAX_DATA_COUNT 16383 /* fit 14 bit count into 2 bytes with flags */
+
+/* For coding runs of tokens */
+static int last_token = -1;
+static int run_start;
+static int last_run_end;
+
+/* Deflation state */
+static z_stream tx_strm;
+
+/* Output buffer */
+static char *obuf = NULL;
+
+/* Send a deflated token */
+static void
+send_deflated_token(int f, int token,
+ struct map_struct *buf, int offset, int nb, int toklen)
+{
+ int n, r;
+ static int init_done;
+
+ if (last_token == -1) {
+ /* initialization */
+ if (!init_done) {
+ tx_strm.next_in = NULL;
+ tx_strm.zalloc = z_alloc;
+ tx_strm.zfree = z_free;
+ if (deflateInit2(&tx_strm, Z_DEFAULT_COMPRESSION, 8,
+ -15, 8, Z_DEFAULT_STRATEGY, -4) != Z_OK) {
+ fprintf(FERROR, "compression init failed\n");
+ exit_cleanup(1);
+ }
+ if ((obuf = malloc(MAX_DATA_COUNT+2)) == NULL)
+ out_of_memory("send_deflated_token");
+ init_done = 1;
+ } else
+ deflateReset(&tx_strm);
+ run_start = token;
+ last_run_end = 0;
+
+ } else if (nb != 0 || token != last_token + 1
+ || token >= run_start + 65536) {
+ /* output previous run */
+ r = run_start - last_run_end;
+ n = last_token - run_start;
+ if (r >= 0 && r <= 63) {
+ write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
+ } else {
+ write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
+ write_int(f, run_start);
+ }
+ if (n != 0) {
+ write_byte(f, n);
+ write_byte(f, n >> 8);
+ }
+ last_run_end = last_token;
+ run_start = token;
+ }
+
+ last_token = token;
+
+ if (nb != 0) {
+ /* deflate the data starting at offset */
+ tx_strm.avail_in = 0;
+ tx_strm.avail_out = 0;
+ do {
+ if (tx_strm.avail_in == 0 && nb != 0) {
+ /* give it some more input */
+ n = MIN(nb, CHUNK_SIZE);
+ tx_strm.next_in = map_ptr(buf, offset, n);
+ tx_strm.avail_in = n;
+ nb -= n;
+ offset += n;
+ }
+ if (tx_strm.avail_out == 0) {
+ tx_strm.next_out = obuf + 2;
+ tx_strm.avail_out = MAX_DATA_COUNT;
+ }
+ r = deflate(&tx_strm, nb? Z_NO_FLUSH: Z_PACKET_FLUSH);
+ if (r != Z_OK) {
+ fprintf(FERROR, "deflate returned %d\n", r);
+ exit_cleanup(1);
+ }
+ if (nb == 0 || tx_strm.avail_out == 0) {
+ n = MAX_DATA_COUNT - tx_strm.avail_out;
+ if (n > 0) {
+ obuf[0] = DEFLATED_DATA + (n >> 8);
+ obuf[1] = n;
+ write_buf(f, obuf, n+2);
+ }
+ }
+ } while (nb != 0 || tx_strm.avail_out == 0);
+ }
+
+ if (token != -1) {
+ /* add the data in the current block to the compressor's
+ history and hash table */
+ tx_strm.next_in = map_ptr(buf, offset, toklen);
+ tx_strm.avail_in = toklen;
+ tx_strm.next_out = NULL;
+ tx_strm.avail_out = 2 * toklen;
+ r = deflate(&tx_strm, Z_INSERT_ONLY);
+ if (r != Z_OK || tx_strm.avail_in != 0) {
+ fprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
+ r, tx_strm.avail_in);
+ exit_cleanup(1);
+ }
+
+ } else {
+ /* end of file - clean up */
+ write_byte(f, END_FLAG);
+ }
+}
+