Another set of compression patches from Jerry.

[dump.git] / dump / tape.c

diff --git a/dump/tape.c b/dump/tape.c
index 1464812010f5f3f74ebe043796651115d05ed69c..3f2ae89a651bedf6f37189240cc2b5ff8352b09f 100644 (file)
--- a/dump/tape.c
+++ b/dump/tape.c
@@ -41,7 +41,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-       "$Id: tape.c,v 1.45 2001/04/27 15:22:47 stelian Exp $";
+       "$Id: tape.c,v 1.46 2001/05/12 11:36:12 stelian Exp $";
 #endif /* not lint */
 
 #include <config.h>
@@ -888,6 +888,7 @@ restore_check_point:
                spcl.c_volume++;
                spcl.c_type = TS_TAPE;
                spcl.c_flags |= DR_NEWHEADER;
+               spcl.c_ntrec = ntrec;
                if (compressed)
                        spcl.c_flags |= DR_COMPRESSED;
                writeheader((dump_ino_t)slp->inode);
@@ -1046,7 +1047,7 @@ doslave(int cmd, int slave_number)
        char *buffer;
 #ifdef HAVE_ZLIB
        struct tapebuf *comp_buf = NULL;
-       int compresult, do_compress = 0;
+       int compresult, do_compress = slave_number > 0;
        unsigned long worklen;
 #endif /* HAVE_ZLIB */
        struct slave_results returns;
@@ -1119,24 +1120,24 @@ doslave(int cmd, int slave_number)
 
 #ifdef HAVE_ZLIB
                /* 
-                * When writing a compressed dump, each block is
-                * written from struct tapebuf with an 4 byte prefix
+                * When writing a compressed dump, each block except
+                * the first one on each tape 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.
+                * The first block written by each slave is not compressed
+                * and does not have a prefix.
                 */
 
-               if (compressed) {
+               if (compressed && do_compress) {
                        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) {
+                       compresult = compress2(comp_buf->buf, &worklen,
+                               (char *)slp->tblock[0], writesize, compressed);
+                       if (compresult == Z_OK && worklen <= (writesize - 16)) {
                                /* write the compressed buffer */
                                comp_buf->length = worklen;
                                comp_buf->compressed = 1;
@@ -1153,7 +1154,7 @@ doslave(int cmd, int slave_number)
                                memcpy(comp_buf->buf, (char *)slp->tblock[0], writesize);
                        }
                }
-               /* compress the remaining blocks */
+               /* compress the remaining blocks if we're compressing */
                do_compress = compressed;
 #endif /* HAVE_ZLIB */