NAME
AnyEvent::Handle::Writer - Extended version of AnyEvent::Handle with
additional write options
SYNOPSIS
use AnyEvent;
use AnyEvent::Handle::Writer;
my $hdl; $hdl = AnyEvent::Handle::Writer->new(
fh => $fh,
on_error => sub {
my ($hdl, $fatal, $msg) = @_;
warn "got error $msg\n";
$hdl->destroy;
}
);
# Custom writer
$hdl->push_write(sub {
my $h = shift;
if ($have_data) {
$h->unshift_write($data);
return 1; # Work done
} else {
return 0; # Work not done, call me again
}
});
# sendfile
$hdl->push_sendfile('/path/to/file', 1024);
RATIONALE
We have great l<AnyEvent::Handle>. But it have only raw write queue.
This module extends it with callbacks in write queue and adds a
"push_sendfile()" call, which would be processed at correct time
METHODS
push_write($data)
"WRITE_QUEUE" in AnyEvent::Handle
push_write(type => @args)
"WRITE_QUEUE" in AnyEvent::Handle
push_write($cb->($handle))
This version of call allow to push a callback, which will be invoked
when the write queue before it became empty.
Callback should return:
true - when there is no work to be done with this callback.
it will be removed from queue and continue
false - when it want to be called again (i.e. not all work was done)
it will be kept in queue and called on next drain
This call allow us to implement such a thing:
$handle->push_write("HTTP/1.1 200 OK\012\015\012\015");
$handle->push_write(sub {
# Manual work on handle
my $h = shift;
my $len = syswrite($h->{fh}, $data); # Here may be also sendfile work
if (defined $len) {
diag "written $len";
substr $data, 0, $len, "";
if (length $data) {
return 0; # want be called again
} else {
return 1; # all done
}
} elsif (!$!{EAGAIN} and !$!{EINTR} and !$!{WSAEWOULDBLOCK}) {
$h->_error ($!, 1);
return 1; # No more requests to me, got an error
}
else { return 0; }
});
$handle->push_write("HTTP/1.1 200 OK\012\015\012\015");
$handle->push_write("Common response");
unshift_write($data)
=head2 unshift_write(type => @args)
=head2 unshift_write($cb->($handle))
Analogically to "unshift_read", it unshift write data at the beginngin
of queue. The only recommended usage is from write callback
$handle->push_write("1")
$handle->push_write(sub {
my $h = shift;
$h->unshift_write("2");
return 1;
});
$handle->push_write("3");
# The output will be "123"
push_sendfile($filename, [$size, [$offset]]);
Push sendfile operation into write queue. If sendfile cannot be found
(Sys::Sendfile) or if it fails with one of ENOSYS, ENOTSUP, EOPNOTSUPP,
EAFNOSUPPORT, EPROTOTYPE or ENOTSOCK, it will be emulated with chunked
read/write
$handle->push_write("HTTP/1.0 200 OK\nContent-length: $size\n...\n\n");
$handle->push_sendfile($file, $size, $offset);
ACKNOWLEDGEMENTS
AUTHOR
Mons Anderson, "<mons at cpan.org>"
LICENSE
This program is free software; you can redistribute it and/or modify it
under the terms of either: the GNU General Public License as published
by the Free Software Foundation; or the Artistic License.
