/ 
Protocol-HTTP2-1.11
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/ Protocol::HTTP2::Client

NAME

Protocol::HTTP2::Client - HTTP/2 client

SYNOPSIS

use Protocol::HTTP2::Client;

# Create client object
my $client = Protocol::HTTP2::Client->new;

# Prepare first request
$client->request(

    # HTTP/2 headers
    ':scheme'    => 'http',
    ':authority' => 'localhost:8000',
    ':path'      => '/',
    ':method'    => 'GET',

    # HTTP/1.1 headers
    headers      => [
        'accept'     => '*/*',
        'user-agent' => 'perl-Protocol-HTTP2/0.13',
    ],

    # Callback when receive server's response
    on_done => sub {
        my ( $headers, $data ) = @_;
        ...
    },
);

# Protocol::HTTP2 is just HTTP/2 protocol decoder/encoder
# so you must create connection yourself

use AnyEvent;
use AnyEvent::Socket;
use AnyEvent::Handle;
my $w = AnyEvent->condvar;

# Plain-text HTTP/2 connection
tcp_connect 'localhost', 8000, sub {
    my ($fh) = @_ or die "connection failed: $!\n";
    
    my $handle;
    $handle = AnyEvent::Handle->new(
        fh       => $fh,
        autocork => 1,
        on_error => sub {
            $_[0]->destroy;
            print "connection error\n";
            $w->send;
        },
        on_eof => sub {
            $handle->destroy;
            $w->send;
        }
    );

    # First write preface to peer
    while ( my $frame = $client->next_frame ) {
        $handle->push_write($frame);
    }

    # Receive servers frames
    # Reply to server
    $handle->on_read(
        sub {
            my $handle = shift;

            $client->feed( $handle->{rbuf} );

            $handle->{rbuf} = undef;
            while ( my $frame = $client->next_frame ) {
                $handle->push_write($frame);
            }

            # Terminate connection if all done
            $handle->push_shutdown if $client->shutdown;
        }
    );
};

$w->recv;

DESCRIPTION

Protocol::HTTP2::Client is HTTP/2 client library. It's intended to make http2-client implementations on top of your favorite event-loop.

METHODS

new

Initialize new client object

my $client = Protocol::HTTP2::Client->new( %options );

Available options:

on_push => sub {...}

If server send push promise this callback will be invoked

on_push => sub {
    # received PUSH PROMISE headers
    my $pp_header = shift;
    ...

    # if we want reject this push
    # return undef

    # if we want to accept pushed resource
    # return callback to receive data
    return sub {
        my ( $headers, $data ) = @_;
        ...
    }
},
upgrade => 0|1

Use HTTP/1.1 Upgrade to upgrade protocol from HTTP/1.1 to HTTP/2. Upgrade possible only on plain (non-tls) connection. Default value is 0.

See Starting HTTP/2 for "http" URIs

keepalive => 0|1

Keep connection alive after requests. Default value is 0. Don't forget to explicitly call close method if set this to true.

on_error => sub {...}

Callback invoked on protocol errors

on_error => sub {
    my $error = shift;
    ...
},
on_change_state => sub {...}

Callback invoked every time when http/2 streams change their state. See Stream States

on_change_state => sub {
    my ( $stream_id, $previous_state, $current_state ) = @_;
    ...
},

request

Prepare HTTP/2 request.

$client->request(

    # HTTP/2 headers
    ':scheme'    => 'http',
    ':authority' => 'localhost:8000',
    ':path'      => '/items',
    ':method'    => 'POST',

    # HTTP/1.1 headers
    headers      => [
        'content-type' => 'application/x-www-form-urlencoded',
        'user-agent' => 'perl-Protocol-HTTP2/0.06',
    ],

    # Callback when receive server's response
    on_done => sub {
        my ( $headers, $data ) = @_;
        ...
    },

    # Callback when receive stream reset
    on_error => sub {
        my $error_code = shift;
    },

    # Body of POST request
    data => "hello=world&test=done",
);

You can chaining request one by one:

$client->request( 1-st request )->request( 2-nd request );

Available callbacks:

on_done => sub {...}

Invoked when full servers response is available

on_done => sub {
    my ( $headers, $data ) = @_;
    ...
},
on_headers => sub {...}

Invoked as soon as headers have been successfully received from the server

on_headers => sub {
    my $headers = shift;
    ...

    # if we want reject any data
    # return undef

    # continue
    return 1
}
on_data => sub {...}

If specified all data will be passed to this callback instead if on_done. on_done will receive empty string.

on_data => sub {
    my ( $partial_data, $headers ) = @_;
    ...

    # if we want cancel download
    # return undef

    # continue downloading
    return 1
}
on_error => sub {...}

Callback invoked on stream errors

on_error => sub {
    my $error = shift;
    ...
}

keepalive

Keep connection alive after requests

my $bool = $client->keepalive;
$client = $client->keepalive($bool);

shutdown

Get connection status:

0 - active
1 - closed (you can terminate connection)

close

Explicitly close connection (send GOAWAY frame). This is required if client has keepalive option enabled.

next_frame

get next frame to send over connection to server. Returns:

undef - on error
0 - nothing to send
binary string - encoded frame
# Example
while ( my $frame = $client->next_frame ) {
    syswrite $fh, $frame;
}

feed

Feed decoder with chunks of server's response

sysread $fh, $binary_data, 4096;
$client->feed($binary_data);

ping

Send ping frame to server (to keep connection alive)

$client->ping

or

$client->ping($payload);

Payload can be arbitrary binary string and must contain 8 octets. If payload argument is omitted client will send random data.