+
+ /* Try to write the data... */
+ wrote = 0;
+ eot_count = 0;
+ size = 0;
+ buffer = (char *) slp->tblock[0]; /* set write pointer */
+ bufsize = writesize; /* length to write */
+ returns.clen = returns.unclen = bufsize;
+
+#ifdef HAVE_ZLIB
+ /*
+ * When writing a compressed dump, each block is
+ * written from struct tapebuf with an 4 byte prefix
+ * followed by the data. This can be less than
+ * writesize. Restore, on a short read, can compare the
+ * length read to the compressed length in the header
+ * to verify that the read was good. Blocks which don't
+ * compress well are written uncompressed.
+ * The first block written by each slave is not compressed.
+ */
+
+ if (compressed) {
+ comp_buf->length = bufsize;
+ worklen = TP_BSIZE + writesize;
+ compresult = Z_DATA_ERROR;
+ if (do_compress)
+ compresult = compress2(comp_buf->buf, &worklen,
+ (char *)slp->tblock[0], writesize, compressed);
+ if (compresult == Z_OK && worklen <= writesize-32) {
+ /* write the compressed buffer */
+ comp_buf->length = worklen;
+ comp_buf->compressed = 1;
+ buffer = (char *) comp_buf;
+ returns.clen = bufsize = worklen + sizeof(struct tapebuf);
+ }
+ else {
+ /* write the data uncompressed */
+ comp_buf->length = writesize;
+ comp_buf->compressed = 0;
+ buffer = (char *) comp_buf;
+ returns.clen = bufsize = writesize + sizeof(struct tapebuf);
+ returns.unclen = returns.clen;
+ memcpy(comp_buf->buf, (char *)slp->tblock[0], writesize);
+ }
+ }
+ /* compress the remaining blocks */
+ do_compress = compressed;
+#endif /* HAVE_ZLIB */
+
+ if (sigsetjmp(jmpbuf, 1) == 0) {