New compile_cdrskin.sh option -o_direct (Linux only)

cdrskin/cdrfifo.c

@@ -25,6 +25,10 @@
 #include <sys/time.h>
 #include <sys/select.h>
 
+#ifdef Cdrskin_read_o_direcT
+#include <sys/mman.h>
+#endif /* Cdrskin_read_o_direcT */
+
 #include "cdrfifo.h"
 
 
@@ -174,9 +178,18 @@ int Cdrfifo_new(struct CdrfifO **ff, int source_fd, int dest_fd,
  o->follow_up_fd_idx= -1;
  o->next= o->prev= NULL;
  o->chain_idx= 0;
+
+#ifdef Cdrskin_read_o_direcT
+ o->buffer= mmap(NULL, (size_t) buffer_size, PROT_READ | PROT_WRITE,
+                 MAP_SHARED | MAP_ANONYMOUS, -1, (off_t) 0);
+ if(o->buffer == MAP_FAILED)
+   goto failed;
+#else
  o->buffer= TSOB_FELD(char,buffer_size);
  if(o->buffer==NULL)
    goto failed;
+#endif /* Cdrskin_read_o_direcT */
+
  return(1);
 failed:;
  Cdrfifo_destroy(ff,0);
@@ -226,8 +239,14 @@ int Cdrfifo_destroy(struct CdrfifO **ff, int flag)
 
  if(o->iso_fs_descr!=NULL)
    free((char *) o->iso_fs_descr);
+
  if(o->buffer!=NULL)
+#ifdef Cdrskin_read_o_direcT
+   munmap(o->buffer, o->buffer_size);
+#else
    free((char *) o->buffer);
+#endif /* Cdrskin_read_o_direcT */
+
  free((char *) o);
  (*ff)= NULL;
  return(1);
@@ -659,6 +678,49 @@ return: <0 = error , 0 = idle , 1 = did some work
 after_write:;
  if(o->source_fd>=0) if(FD_ISSET((o->source_fd),rds)) {
    can_read= o->buffer_size - o->write_idx;
+
+#ifdef Cdrskin_read_o_direcT
+
+   /* ts A91115
+      This chunksize must be aligned to filesystem blocksize.
+      One might try to inquire the block size behind o->source_fd, but since
+      O_DIRECT is a dirty hack anyway, i just guess that 64 KiB is divisible
+      by any existing block size on Linux.
+    */
+#define Cdrfifo_o_direct_chunK 65536
+
+   if(o->write_idx < o->read_idx && o->write_idx + can_read > o->read_idx)
+     can_read= o->read_idx - o->write_idx;
+   if(o->fd_in_limit>=0.0)
+     if(can_read > o->fd_in_limit - o->fd_in_counter)
+       can_read= o->fd_in_limit - o->fd_in_counter;
+   /* Make sure to read with properly aligned size */
+   if(can_read > Cdrfifo_o_direct_chunK)
+     can_read= Cdrfifo_o_direct_chunK;
+   else if(can_read < Cdrfifo_o_direct_chunK)
+     can_read= -1;
+   ret= 0;
+   if(can_read>0)
+     ret= read(o->source_fd,o->buffer+o->write_idx,can_read);
+   if(can_read < 0) {
+     /* waiting for a full Cdrfifo_o_direct_chunK to fit */
+     if(can_write <= 0 && o->dest_fd >= 0) {
+        fd_set rds,wts,exs;
+        struct timeval wt;
+
+        FD_ZERO(&rds);
+        FD_ZERO(&wts);
+        FD_ZERO(&exs);
+        FD_SET((o->dest_fd),&wts);
+        wt.tv_sec=  0;
+        wt.tv_usec= 10000;
+        select(o->dest_fd + 1,&rds, &wts, &exs, &wt);
+
+     }
+   } else
+
+#else /* Cdrskin_read_o_direcT */
+
    if(can_read>o->chunk_size)
      can_read= o->chunk_size;
    if(o->write_idx<o->read_idx && o->write_idx+can_read > o->read_idx)
@@ -669,6 +731,9 @@ after_write:;
    ret= 0;
    if(can_read>0)
      ret= read(o->source_fd,o->buffer+o->write_idx,can_read);
+
+#endif /* ! Cdrskin_read_o_direcT */
+
    if(ret==-1) {
 
      /* >>> handle input error */;

cdrskin/cdrskin.c

@@ -339,6 +339,23 @@ or
 /** Verbosity level for fifo debugging */
 #define Cdrskin_verbose_debug_fifO 4
 
+#ifdef Cdrskin_read_o_direcT
+/* Linux 2.6.18:
+   This can avoid low write speed via USB with 32 KB SCSI write chunks.
+   64 KB write chunking is 20% more effective, though, and this size is
+   not in need for O_DIRECT.
+   Strange: Vanilla read() brings USB 32 KB WRITE down from 11x to 7.5x.
+   Throughput from /dev/zero to /dev/null is 230x. The disk delivers 56x.
+   Clearly Linux USB has a problem with 32 KB chunks. read() without O_DIRECT
+   makes it worse.
+   cdrecord and growisofs bring 11x. At least growisofs uses O_DIRECT for its
+   fifo input.
+*/
+# ifndef _GNU_SOURCE
+#  define _GNU_SOURCE
+# endif
+#endif /* Cdrskin_read_o_direcT */
+
 
 #include <stdio.h>
 #include <ctype.h>
@@ -1388,7 +1405,11 @@ int Cdrtrack_open_source_path(struct CdrtracK *track, int *fd, int flag)
    if(is_wav==-3)
      return(0);
    if(is_wav==0)
-     *fd= open(track->source_path,O_RDONLY);
+#ifdef Cdrskin_read_o_direcT
+     *fd= open64(track->source_path, O_RDONLY | O_DIRECT);
+#else
+     *fd= open(track->source_path, O_RDONLY);
+#endif
    if(*fd==-1) {
      fprintf(stderr,"cdrskin: failed to open source address '%s'\n",
              track->source_path);

cdrskin/cdrskin_timestamp.h

@@ -1 +1 @@
-#define Cdrskin_timestamP "2009.11.15.115923"
+#define Cdrskin_timestamP "2009.11.15.152541"

cdrskin/compile_cdrskin.sh

@@ -55,6 +55,9 @@ do
   elif test "$i" = "-no_largefile"
   then
     largefile_opts=	
+  elif test "$i" = "-o_direct"
+  then
+    def_opts="$def_opts -DCdrskin_read_o_direcT"
   elif test "$i" = "-do_not_compile_cdrskin"
   then
     compile_cdrskin=0
@@ -77,6 +80,7 @@ do
     echo "  -compile_dewav    compile program test/dewav without libburn."
     echo "  -libburn_0_7_2    set macro to match libburn-0.7.2"
     echo "  -libburn_svn      set macro to match current libburn-SVN."
+    echo "  -o_direct         use open(O_DIRECT) on fifo input (Linux only)."
     echo "  -do_not_compile_cdrskin  omit compilation of cdrskin/cdrskin."
     echo "  -experimental     use newly introduced libburn features."
     echo "  -oldfashioned     use pre-0.2.2 libburn features only."