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changeset 13003:74c5fa5cef47

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use unwind_protect to ensure wavread closes file. * wavread.m: Use unwind_protect to ensure file is closed.
author John W. Eaton <jwe@octave.org>
date Wed, 24 Aug 2011 14:25:42 -0400
parents ad59cda5015c
children d9d65c3017c3
files scripts/audio/wavread.m
diffstat 1 files changed, 117 insertions(+), 114 deletions(-) [+]
line wrap: on
line diff
--- a/scripts/audio/wavread.m
+++ b/scripts/audio/wavread.m
@@ -55,136 +55,139 @@
     error ("wavread: FILENAME must be a character string");
   endif
 
-  # Open file for binary reading.
-  [fid, msg] = fopen (filename, "rb");
-  if (fid < 0)
-    error ("wavread: %s", msg);
-  endif
+  fid = -1;
+
+  unwind_protect
 
-  ## Get file size.
-  fseek (fid, 0, "eof");
-  file_size = ftell (fid);
-  fseek (fid, 0, "bof");
+    [fid, msg] = fopen (filename, "rb");
+
+    if (fid < 0)
+      error ("wavread: %s", msg);
+    endif
 
-  ## Find RIFF chunk.
-  riff_size = find_chunk (fid, "RIFF", file_size);
-  riff_pos = ftell (fid);
-  if (riff_size == -1)
-    fclose (fid);
-    error ("wavread: file contains no RIFF chunk");
-  endif
+    ## Get file size.
+    fseek (fid, 0, "eof");
+    file_size = ftell (fid);
+    fseek (fid, 0, "bof");
 
-  riff_type = char (fread (fid, 4))';
-  if (! strcmp (riff_type, "WAVE"))
-    fclose (fid);
-    error ("wavread: file contains no WAVE signature");
-  endif
-  riff_pos = riff_pos + 4;
-  riff_size = riff_size - 4;
+    ## Find RIFF chunk.
+    riff_size = find_chunk (fid, "RIFF", file_size);
+    riff_pos = ftell (fid);
+    if (riff_size == -1)
+      error ("wavread: file contains no RIFF chunk");
+    endif
+
+    riff_type = char (fread (fid, 4))';
+    if (! strcmp (riff_type, "WAVE"))
+      error ("wavread: file contains no WAVE signature");
+    endif
+    riff_pos = riff_pos + 4;
+    riff_size = riff_size - 4;
 
-  ## Find format chunk inside the RIFF chunk.
-  fseek (fid, riff_pos, "bof");
-  fmt_size = find_chunk (fid, "fmt ", riff_size);
-  fmt_pos = ftell(fid);
-  if (fmt_size == -1)
-    fclose (fid);
-    error ("wavread: file contains no format chunk");
-  endif
+    ## Find format chunk inside the RIFF chunk.
+    fseek (fid, riff_pos, "bof");
+    fmt_size = find_chunk (fid, "fmt ", riff_size);
+    fmt_pos = ftell(fid);
+    if (fmt_size == -1)
+      error ("wavread: file contains no format chunk");
+    endif
+
+    ## Find data chunk inside the RIFF chunk.
+    ## We don't assume that it comes after the format chunk.
+    fseek (fid, riff_pos, "bof");
+    data_size = find_chunk (fid, "data", riff_size);
+    data_pos = ftell (fid);
+    if (data_size == -1)
+      error ("wavread: file contains no data chunk");
+    endif
 
-  ## Find data chunk inside the RIFF chunk.
-  ## We don't assume that it comes after the format chunk.
-  fseek (fid, riff_pos, "bof");
-  data_size = find_chunk (fid, "data", riff_size);
-  data_pos = ftell (fid);
-  if (data_size == -1)
-    fclose (fid);
-    error ("wavread: file contains no data chunk");
-  endif
+    ### Read format chunk.
+    fseek (fid, fmt_pos, "bof");
 
-  ### Read format chunk.
-  fseek (fid, fmt_pos, "bof");
+    ## Sample format code.
+    format_tag = fread (fid, 1, "uint16", 0, BYTEORDER);
+    if (format_tag != FORMAT_PCM && format_tag != FORMAT_IEEE_FLOAT)
+      error ("wavread: sample format %#x is not supported", format_tag);
+    endif
 
-  ## Sample format code.
-  format_tag = fread (fid, 1, "uint16", 0, BYTEORDER);
-  if (format_tag != FORMAT_PCM && format_tag != FORMAT_IEEE_FLOAT)
-    fclose (fid);
-    error ("wavread: sample format %#x is not supported", format_tag);
-  endif
+    ## Number of interleaved channels.
+    channels = fread (fid, 1, "uint16", 0, BYTEORDER);
 
-  ## Number of interleaved channels.
-  channels = fread (fid, 1, "uint16", 0, BYTEORDER);
+    ## Sample rate.
+    samples_per_sec = fread (fid, 1, "uint32", 0, BYTEORDER);
 
-  ## Sample rate.
-  samples_per_sec = fread (fid, 1, "uint32", 0, BYTEORDER);
+    ## Bits per sample.
+    fseek (fid, 6, "cof");
+    bits_per_sample = fread (fid, 1, "uint16", 0, BYTEORDER);
 
-  ## Bits per sample.
-  fseek (fid, 6, "cof");
-  bits_per_sample = fread (fid, 1, "uint16", 0, BYTEORDER);
+    ### Read data chunk.
+    fseek (fid, data_pos, "bof");
 
-  ### Read data chunk.
-  fseek (fid, data_pos, "bof");
+    ## Determine sample data type.
+    if (format_tag == FORMAT_PCM)
+      switch (bits_per_sample)
+        case 8
+          format = "uint8";
+        case 16
+          format = "int16";
+        case 24
+          format = "uint8";
+        case 32
+          format = "int32";
+        otherwise
+          error ("wavread: %d bits sample resolution is not supported with PCM",
+                 bits_per_sample);
+      endswitch
+    else
+      switch (bits_per_sample)
+        case 32
+          format = "float32";
+        case 64
+          format = "float64";
+        otherwise
+          error ("wavread: %d bits sample resolution is not supported with IEEE float",
+                 bits_per_sample);
+      endswitch
+    endif
 
-  ## Determine sample data type.
-  if (format_tag == FORMAT_PCM)
-    switch (bits_per_sample)
-      case 8
-        format = "uint8";
-      case 16
-        format = "int16";
-      case 24
-        format = "uint8";
-      case 32
-        format = "int32";
-      otherwise
-        fclose (fid);
-        error ("wavread: %d bits sample resolution is not supported with PCM",
-               bits_per_sample);
-    endswitch
-  else
-    switch (bits_per_sample)
-      case 32
-        format = "float32";
-      case 64
-        format = "float64";
-      otherwise
-        fclose (fid);
-        error ("wavread: %d bits sample resolution is not supported with IEEE float",
-               bits_per_sample);
-    endswitch
-  endif
+    ## Parse arguments.
+    if (nargin == 1)
+      length = idivide (8 * data_size, bits_per_sample);
+    else
+      nparams = numel (param);
+      if (nparams == 1)
+        ## Number of samples is given.
+        length = param * channels;
+      elseif (nparams == 2)
+        ## Sample range is given.
+        if (fseek (fid, (param(1)-1) * channels * (bits_per_sample/8), "cof") < 0)
+          warning ("wavread: seeking failed");
+        endif
+        length = (param(2)-param(1)+1) * channels;
+      elseif (nparams == 4 && char (param) == "size")
+        ## Size of the file is requested.
+        tmp = idivide (8 * data_size, channels * bits_per_sample);
+        y = [tmp, channels];
+        return;
+      else
+        error ("wavread: invalid PARAM argument");
+      endif
+    endif
 
-  ## Parse arguments.
-  if (nargin == 1)
-    length = idivide (8 * data_size, bits_per_sample);
-  else
-    nparams = numel (param);
-    if (nparams == 1)
-      ## Number of samples is given.
-      length = param * channels;
-    elseif (nparams == 2)
-      ## Sample range is given.
-      if (fseek (fid, (param(1)-1) * channels * (bits_per_sample/8), "cof") < 0)
-        warning ("wavread: seeking failed");
-      endif
-      length = (param(2)-param(1)+1) * channels;
-    elseif (nparams == 4 && char (param) == "size")
-      ## Size of the file is requested.
+    ## Read samples and close file.
+    if (bits_per_sample == 24)
+      length *= 3;
+    endif
+
+    [yi, n] = fread (fid, length, format, 0, BYTEORDER);
+
+  unwind_protect_cleanup
+
+    if (fid >= 0)
       fclose (fid);
-      tmp = idivide (8 * data_size, channels * bits_per_sample);
-      y = [tmp, channels];
-      return;
-    else
-      fclose (fid);
-      error ("wavread: invalid PARAM argument");
     endif
-  endif
 
-  ## Read samples and close file.
-  if (bits_per_sample == 24)
-    length *= 3;
-  endif
-  [yi, n] = fread (fid, length, format, 0, BYTEORDER);
-  fclose (fid);
+  end_unwind_protect
 
   ## Check data.
   if (mod (numel (yi), channels) != 0)