Unbounded memory stream?

[Mike Acton]

Is there an undocumented way to create an unbounded memory stream? 

Documentation states that fifo:// stream requires size. 

• There's no (optional?) realloc when pre-allocation limit is reached?
  
• There's no callback if I hit the end, so no way to realloc in the client code.
  
• If it's used as a destination stream in a Stream.readUntil, it's not clear what happens when the limit is reached.
  

Use case:

• Reading multipart/form-data (http://www.ietf.org/rfc/rfc1867.txt)
  
• Part sizes not known in advance. They are delimited by boundary text.
  

Work-around:

• Create temporary file stream (see also: Other request for mkstemp)
  
• Use temp stream as destination if Stream.readUntilBytes
  
• Read back in from temporary file stream into return var.
  
• Delete temporary file stream (see also: remove() is not in global)

This is obviously not ideal or fast.

Code: https://gist.github.com/1806537

e.g. header_line = this.readlnBoundary( '\u000d\u000a' ); 

system.tmpfile = function() {
  var d = new Date();
  var r = String(Math.random()).replace(/\./,'');;
  var n = '/tmp/tmp-' + r + '-' + d.valueOf();
  var s = new Stream( n, 'w+' );
  return s;
}

Stream.prototype.readBinBoundary = function( boundary ) {
  var tmp_file = system.tmpfile();
  var tmp_name = tmp_file.name;
  
  this.readUntilBytes( boundary, tmp_file );
  tmp_file.close();
  
  return (tmp_name);
} 

Stream.prototype.readlnBoundary = function( boundary ) {
  var tmp_name  = this.readBinBoundary( boundary );
  var ln_stream = new Stream( tmp_name );
  var ln_text   = ln_stream.readFile();
  
  ln_stream.close();
  system.remove( tmp_name );
  
  return ln_text;
} 

Anyone have another suggestion for a less roundabout solution?

Mike.

[Shanti Rao]

M = new Stream();

Is an unbounded auto-extending memory stream.

[Mike Acton]

Ha! Thanks. That should simplify things a bit. :)