[iso] initial ISO image support (EXPERIMENTAL)

* from libcdio: http://www.gnu.org/software/libcdio/

src/libcdio/driver/_cdio_stdio.c

@@ -0,0 +1,260 @@
+/*
+  Copyright (C) 2003, 2004, 2005, 2008, 2011 Rocky Bernstein <rocky@gnu.org>
+  Copyright (C) 2000 Herbert Valerio Riedel <hvr@gnu.org>
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+# define __CDIO_CONFIG_H__ 1
+#endif
+
+#ifdef HAVE_STDIO_H
+#include <stdio.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h> 
+#endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+
+#include <cdio/logging.h>
+#include <cdio/util.h>
+#include "_cdio_stream.h"
+#include "_cdio_stdio.h"
+
+/* On 32 bit platforms, fseek can only access streams of 2 GB or less.
+   Prefer fseeko/fseeko64, that take a 64 bit offset when LFS is enabled */
+#if defined(HAVE_FSEEKO64) && defined(_FILE_OFFSET_BITS) && (_FILE_OFFSET_BITS == 64)
+#define CDIO_FSEEK fseeko64
+#elif defined(HAVE_FSEEKO)
+#define CDIO_FSEEK fseeko
+#else
+#define CDIO_FSEEK fseek
+#endif
+
+/* Use _stati64 if needed, on platforms that don't have transparent LFS support */
+#if defined(HAVE__STATI64) && defined(_FILE_OFFSET_BITS) && (_FILE_OFFSET_BITS == 64)
+#define CDIO_STAT _stati64
+#else
+#define CDIO_STAT stat
+#endif
+
+#define _STRINGIFY(a) #a
+#define STRINGIFY(a) _STRINGIFY(a)
+
+static const char _rcsid[] = "$Id: _cdio_stdio.c,v 1.6 2008/04/22 15:29:11 karl Exp $";
+
+#define CDIO_STDIO_BUFSIZE (128*1024)
+
+typedef struct {
+  char *pathname;
+  FILE *fd;
+  char *fd_buf;
+  off_t st_size; /* used only for source */
+} _UserData;
+
+static int
+_stdio_open (void *user_data) 
+{
+  _UserData *const ud = user_data;
+  
+  if ((ud->fd = fopen (ud->pathname, "rb")))
+    {
+      ud->fd_buf = calloc (1, CDIO_STDIO_BUFSIZE);
+      setvbuf (ud->fd, ud->fd_buf, _IOFBF, CDIO_STDIO_BUFSIZE);
+    }
+
+  return (ud->fd == NULL);
+}
+
+static int
+_stdio_close(void *user_data)
+{
+  _UserData *const ud = user_data;
+
+  if (fclose (ud->fd))
+    cdio_error ("fclose (): %s", strerror (errno));
+ 
+  ud->fd = NULL;
+
+  free (ud->fd_buf);
+  ud->fd_buf = NULL;
+
+  return 0;
+}
+
+static void
+_stdio_free(void *user_data)
+{
+  _UserData *const ud = user_data;
+
+  if (ud->pathname)
+    free(ud->pathname);
+
+  if (ud->fd) /* should be NULL anyway... */
+    _stdio_close(user_data); 
+
+  free(ud);
+}
+
+/*! 
+  Like fseek/fseeko(3) and in fact may be the same.
+  
+  This  function sets the file position indicator for the stream
+  pointed to by stream.  The new position, measured in bytes, is obtained
+  by  adding offset bytes to the position specified by whence.  If whence
+  is set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset  is  relative  to
+  the  start of the file, the current position indicator, or end-of-file,
+  respectively.  A successful call to the fseek function clears the end-
+  of-file indicator for the stream and undoes any effects of the
+  ungetc(3) function on the same stream.
+  
+  @return upon successful completion, DRIVER_OP_SUCCESS, else,
+  DRIVER_OP_ERROR is returned and the global variable errno is set to
+  indicate the error.
+*/
+static int 
+_stdio_seek(void *p_user_data, off_t i_offset, int whence)
+{
+  _UserData *const ud = p_user_data;
+  int ret;
+#if !defined(HAVE_FSEEKO) && !defined(HAVE_FSEEKO64)
+  /* Detect if off_t is lossy-truncated to long to avoid data corruption */
+  if ( (sizeof(off_t) > sizeof(long)) && (i_offset != (off_t)((long)i_offset)) ) {
+    cdio_error ( STRINGIFY(CDIO_FSEEK) " (): lossy truncation detected!");
+    errno = EFBIG;
+    return DRIVER_OP_ERROR;
+  }
+#endif
+
+  if ( (ret=CDIO_FSEEK (ud->fd, i_offset, whence)) ) {
+    cdio_error ( STRINGIFY(CDIO_FSEEK) " (): %s", strerror (errno));
+  }
+
+  return ret;
+}
+
+static off_t
+_stdio_stat(void *p_user_data)
+{
+  const _UserData *const ud = p_user_data;
+
+  return ud->st_size;
+}
+
+/*!
+  Like fread(3) and in fact is about the same.
+  
+  DESCRIPTION:
+  The function fread reads nmemb elements of data, each size bytes long,
+  from the stream pointed to by stream, storing them at the location
+  given by ptr.
+  
+  RETURN VALUE:
+  return the number of items successfully read or written (i.e.,
+  not the number of characters).  If an error occurs, or the
+  end-of-file is reached, the return value is a short item count
+  (or zero).
+  
+  We do not distinguish between end-of-file and error, and callers
+  must use feof(3) and ferror(3) to determine which occurred.
+  */
+static ssize_t
+_stdio_read(void *user_data, void *buf, size_t count)
+{
+  _UserData *const ud = user_data;
+  long read_count;
+
+  read_count = fread(buf, 1, count, ud->fd);
+
+  if (read_count != count)
+    { /* fixme -- ferror/feof */
+      if (feof (ud->fd))
+        {
+          cdio_debug ("fread (): EOF encountered");
+          clearerr (ud->fd);
+        }
+      else if (ferror (ud->fd))
+        {
+          cdio_error ("fread (): %s", strerror (errno));
+          clearerr (ud->fd);
+        }
+      else
+        cdio_debug ("fread (): short read and no EOF?!?");
+    }
+
+  return read_count;
+}
+
+/*!
+  Deallocate resources assocaited with obj. After this obj is unusable.
+*/
+void
+cdio_stdio_destroy(CdioDataSource_t *p_obj)
+{
+  cdio_stream_destroy(p_obj);
+}
+
+CdioDataSource_t *
+cdio_stdio_new(const char pathname[])
+{
+  CdioDataSource_t *new_obj = NULL;
+  cdio_stream_io_functions funcs = { NULL, NULL, NULL, NULL, NULL, NULL };
+  _UserData *ud = NULL;
+  struct CDIO_STAT statbuf;
+  
+  if (CDIO_STAT (pathname, &statbuf) == -1) 
+    {
+      cdio_warn ("could not retrieve file info for `%s': %s", 
+                 pathname, strerror (errno));
+      return NULL;
+    }
+
+  ud = calloc (1, sizeof (_UserData));
+
+  ud->pathname = strdup(pathname);
+  ud->st_size  = statbuf.st_size; /* let's hope it doesn't change... */
+
+  funcs.open   = _stdio_open;
+  funcs.seek   = _stdio_seek;
+  funcs.stat   = _stdio_stat;
+  funcs.read   = _stdio_read;
+  funcs.close  = _stdio_close;
+  funcs.free   = _stdio_free;
+
+  new_obj = cdio_stream_new(ud, &funcs);
+
+  return new_obj;
+}
+
+
+/* 
+ * Local variables:
+ *  c-file-style: "gnu"
+ *  tab-width: 8
+ *  indent-tabs-mode: nil
+ * End:
+ */