/ 
Feersum-0.95
/ Feersum::Connection::Handle

NAME

Feersum::Connection::Handle - PSGI-style reader/writer objects.

SYNOPSIS

For read handles:

my $buf;
my $r = delete $env{'psgi.input'};
$r->read($buf, $env{CONTENT_LENGTH});
$r->close(); # discards any un-read() data

# emits a warning and returns 0:
$r->seek(....);

# not yet supported, throws exception:
# $r->poll_cb(sub { .... });

For write handles:

$w->write("scalar");
$w->write(\"scalar ref");
$w->poll_cb(sub {
    # use $_[0] instead of $w to avoid a closure
    $_[0]->write(\"some data");
    # can close() or unregister the poll_cb in here
    $_[0]->close();
});

DESCRIPTION

See the PSGI spec for more information on how read/write handles are used (The Delayed Response and Streaming Body section has details on the writer).

METHODS

Reader methods

The reader is obtained via $env->{'psgi.input'}.

$r->read($buf, $len)

Read the first $len bytes of the request body into the buffer specified by $buf (similar to how sysread works).

The calls to $r->read() will never block. Currently, the entire body is read into memory (or perhaps to a temp file) before the Feersum request handler is even called. This behaviour MAY change. Regardless, Feersum will be doing some buffering so psgix.input.buffered is set in the PSGI env hash.

$r->seek(...)

Seeking is not supported. Feersum discards input data to conserve memory, but only after it has been read.

$r->close()

Discards the remainder of the input buffer.

$r->poll_cb(sub { .... })

NOT YET SUPPORTED. PSGI only defined poll_cb for the Writer object.

Writer methods.

The writer is obtained under PSGI by sending a code/headers pair to the "starter" callback. Under Feersum, calls to $req->start_streaming return one.

$w->write("scalar")

Send the scalar as a "T-E: chunked" chunk.

The calls to $w->write() will never block and data is buffered until transmitted. This behaviour is indicated by psgix.output.buffered in the PSGI env hash (Twiggy supports this too, for example).

$w->write(\"scalar ref")

Works just like write("scalar") above. This extension is indicated by psgix.body.scalar_refs in the PSGI env hash.

$w->close()

Close the HTTP response (which triggers the "T-E: chunked" terminating chunk to be sent).

$w->poll_cb(sub { .... })

Register a callback to be called when the write buffer is empty. Pass in undef to unset. The sub can call close().

A reference to the writer is passed in as the first and only argument to the sub. It's recommended that you use $_[0] rather than closing-over on $w to prevent a circular reference.

AUTHOR

Jeremy Stashewsky, stash@cpan.org

COPYRIGHT AND LICENSE

Copyright (C) 2010 by Jeremy Stashewsky & Socialtext Inc.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.7 or, at your option, any later version of Perl 5 you may have available.