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package AnyEvent::Handle; |
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|
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no warnings; |
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use strict; |
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|
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use AnyEvent (); |
7 |
use AnyEvent::Util qw(WSAEWOULDBLOCK); |
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use Scalar::Util (); |
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use Carp (); |
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use Fcntl (); |
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use Errno qw(EAGAIN EINTR); |
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|
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=head1 NAME |
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|
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AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent |
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|
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=cut |
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|
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our $VERSION = '0.04'; |
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|
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=head1 SYNOPSIS |
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|
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use AnyEvent; |
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use AnyEvent::Handle; |
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|
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my $cv = AnyEvent->condvar; |
27 |
|
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my $handle = |
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AnyEvent::Handle->new ( |
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fh => \*STDIN, |
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on_eof => sub { |
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$cv->broadcast; |
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}, |
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); |
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|
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# send some request line |
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$handle->push_write ("getinfo\015\012"); |
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|
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# read the response line |
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$handle->push_read (line => sub { |
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my ($handle, $line) = @_; |
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warn "read line <$line>\n"; |
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$cv->send; |
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}); |
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|
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$cv->recv; |
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|
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=head1 DESCRIPTION |
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|
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This module is a helper module to make it easier to do event-based I/O on |
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filehandles. For utility functions for doing non-blocking connects and accepts |
52 |
on sockets see L<AnyEvent::Util>. |
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|
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In the following, when the documentation refers to of "bytes" then this |
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means characters. As sysread and syswrite are used for all I/O, their |
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treatment of characters applies to this module as well. |
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|
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All callbacks will be invoked with the handle object as their first |
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argument. |
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|
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=head1 METHODS |
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|
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=over 4 |
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|
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=item B<new (%args)> |
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|
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The constructor supports these arguments (all as key => value pairs). |
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|
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=over 4 |
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|
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=item fh => $filehandle [MANDATORY] |
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|
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The filehandle this L<AnyEvent::Handle> object will operate on. |
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|
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NOTE: The filehandle will be set to non-blocking (using |
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AnyEvent::Util::fh_nonblocking). |
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|
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=item on_eof => $cb->($handle) |
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|
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Set the callback to be called on EOF. |
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|
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While not mandatory, it is highly recommended to set an eof callback, |
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otherwise you might end up with a closed socket while you are still |
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waiting for data. |
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|
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=item on_error => $cb->($handle) |
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|
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This is the fatal error callback, that is called when, well, a fatal error |
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occurs, such as not being able to resolve the hostname, failure to connect |
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or a read error. |
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|
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The object will not be in a usable state when this callback has been |
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called. |
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|
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On callback entrance, the value of C<$!> contains the operating system |
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error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). |
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|
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The callback should throw an exception. If it returns, then |
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AnyEvent::Handle will C<croak> for you. |
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|
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While not mandatory, it is I<highly> recommended to set this callback, as |
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you will not be notified of errors otherwise. The default simply calls |
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die. |
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|
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=item on_read => $cb->($handle) |
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|
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This sets the default read callback, which is called when data arrives |
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and no read request is in the queue. |
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|
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To access (and remove data from) the read buffer, use the C<< ->rbuf >> |
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method or access the C<$handle->{rbuf}> member directly. |
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|
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When an EOF condition is detected then AnyEvent::Handle will first try to |
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feed all the remaining data to the queued callbacks and C<on_read> before |
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calling the C<on_eof> callback. If no progress can be made, then a fatal |
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error will be raised (with C<$!> set to C<EPIPE>). |
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|
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=item on_drain => $cb->($handle) |
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|
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This sets the callback that is called when the write buffer becomes empty |
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(or when the callback is set and the buffer is empty already). |
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|
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To append to the write buffer, use the C<< ->push_write >> method. |
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|
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=item timeout => $fractional_seconds |
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|
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If non-zero, then this enables an "inactivity" timeout: whenever this many |
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seconds pass without a successful read or write on the underlying file |
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handle, the C<on_timeout> callback will be invoked (and if that one is |
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missing, an C<ETIMEDOUT> error will be raised). |
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|
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Note that timeout processing is also active when you currently do not have |
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any outstanding read or write requests: If you plan to keep the connection |
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idle then you should disable the timout temporarily or ignore the timeout |
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in the C<on_timeout> callback. |
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|
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Zero (the default) disables this timeout. |
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|
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=item on_timeout => $cb->($handle) |
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|
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Called whenever the inactivity timeout passes. If you return from this |
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callback, then the timeout will be reset as if some activity had happened, |
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so this condition is not fatal in any way. |
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|
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=item rbuf_max => <bytes> |
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|
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If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) |
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when the read buffer ever (strictly) exceeds this size. This is useful to |
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avoid denial-of-service attacks. |
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|
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For example, a server accepting connections from untrusted sources should |
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be configured to accept only so-and-so much data that it cannot act on |
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(for example, when expecting a line, an attacker could send an unlimited |
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amount of data without a callback ever being called as long as the line |
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isn't finished). |
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|
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=item read_size => <bytes> |
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|
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The default read block size (the amount of bytes this module will try to read |
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on each [loop iteration). Default: C<4096>. |
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|
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=item low_water_mark => <bytes> |
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|
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Sets the amount of bytes (default: C<0>) that make up an "empty" write |
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buffer: If the write reaches this size or gets even samller it is |
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considered empty. |
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|
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=item tls => "accept" | "connect" | Net::SSLeay::SSL object |
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|
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When this parameter is given, it enables TLS (SSL) mode, that means it |
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will start making tls handshake and will transparently encrypt/decrypt |
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data. |
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|
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TLS mode requires Net::SSLeay to be installed (it will be loaded |
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automatically when you try to create a TLS handle). |
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|
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For the TLS server side, use C<accept>, and for the TLS client side of a |
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connection, use C<connect> mode. |
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|
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You can also provide your own TLS connection object, but you have |
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to make sure that you call either C<Net::SSLeay::set_connect_state> |
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or C<Net::SSLeay::set_accept_state> on it before you pass it to |
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AnyEvent::Handle. |
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|
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See the C<starttls> method if you need to start TLs negotiation later. |
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|
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=item tls_ctx => $ssl_ctx |
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|
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Use the given Net::SSLeay::CTX object to create the new TLS connection |
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(unless a connection object was specified directly). If this parameter is |
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missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. |
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|
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=item json => JSON or JSON::XS object |
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|
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This is the json coder object used by the C<json> read and write types. |
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|
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If you don't supply it, then AnyEvent::Handle will create and use a |
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suitable one, which will write and expect UTF-8 encoded JSON texts. |
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|
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Note that you are responsible to depend on the JSON module if you want to |
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use this functionality, as AnyEvent does not have a dependency itself. |
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|
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=item filter_r => $cb |
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|
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=item filter_w => $cb |
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|
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These exist, but are undocumented at this time. |
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|
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=back |
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|
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=cut |
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|
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sub new { |
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my $class = shift; |
215 |
|
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my $self = bless { @_ }, $class; |
217 |
|
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$self->{fh} or Carp::croak "mandatory argument fh is missing"; |
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|
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AnyEvent::Util::fh_nonblocking $self->{fh}, 1; |
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|
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if ($self->{tls}) { |
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require Net::SSLeay; |
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$self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); |
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} |
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|
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# $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; # nop |
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# $self->on_error (delete $self->{on_error}) if $self->{on_error}; # nop |
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# $self->on_read (delete $self->{on_read} ) if $self->{on_read}; # nop |
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$self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; |
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|
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$self->{_activity} = AnyEvent->now; |
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$self->_timeout; |
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|
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$self->start_read; |
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|
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$self |
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} |
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|
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sub _shutdown { |
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my ($self) = @_; |
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|
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delete $self->{_rw}; |
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delete $self->{_ww}; |
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delete $self->{fh}; |
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} |
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|
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sub error { |
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my ($self) = @_; |
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|
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{ |
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local $!; |
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$self->_shutdown; |
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} |
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|
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$self->{on_error}($self) |
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if $self->{on_error}; |
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|
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Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; |
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} |
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|
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=item $fh = $handle->fh |
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|
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This method returns the file handle of the L<AnyEvent::Handle> object. |
265 |
|
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=cut |
267 |
|
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sub fh { $_[0]{fh} } |
269 |
|
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=item $handle->on_error ($cb) |
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|
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Replace the current C<on_error> callback (see the C<on_error> constructor argument). |
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|
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=cut |
275 |
|
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sub on_error { |
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$_[0]{on_error} = $_[1]; |
278 |
} |
279 |
|
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=item $handle->on_eof ($cb) |
281 |
|
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Replace the current C<on_eof> callback (see the C<on_eof> constructor argument). |
283 |
|
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=cut |
285 |
|
286 |
sub on_eof { |
287 |
$_[0]{on_eof} = $_[1]; |
288 |
} |
289 |
|
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=item $handle->on_timeout ($cb) |
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|
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Replace the current C<on_timeout> callback, or disables the callback |
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(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor |
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argument. |
295 |
|
296 |
=cut |
297 |
|
298 |
sub on_timeout { |
299 |
$_[0]{on_timeout} = $_[1]; |
300 |
} |
301 |
|
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############################################################################# |
303 |
|
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=item $handle->timeout ($seconds) |
305 |
|
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Configures (or disables) the inactivity timeout. |
307 |
|
308 |
=cut |
309 |
|
310 |
sub timeout { |
311 |
my ($self, $timeout) = @_; |
312 |
|
313 |
$self->{timeout} = $timeout; |
314 |
$self->_timeout; |
315 |
} |
316 |
|
317 |
# reset the timeout watcher, as neccessary |
318 |
# also check for time-outs |
319 |
sub _timeout { |
320 |
my ($self) = @_; |
321 |
|
322 |
if ($self->{timeout}) { |
323 |
my $NOW = AnyEvent->now; |
324 |
|
325 |
# when would the timeout trigger? |
326 |
my $after = $self->{_activity} + $self->{timeout} - $NOW; |
327 |
|
328 |
# now or in the past already? |
329 |
if ($after <= 0) { |
330 |
$self->{_activity} = $NOW; |
331 |
|
332 |
if ($self->{on_timeout}) { |
333 |
$self->{on_timeout}->($self); |
334 |
} else { |
335 |
$! = Errno::ETIMEDOUT; |
336 |
$self->error; |
337 |
} |
338 |
|
339 |
# callbakx could have changed timeout value, optimise |
340 |
return unless $self->{timeout}; |
341 |
|
342 |
# calculate new after |
343 |
$after = $self->{timeout}; |
344 |
} |
345 |
|
346 |
Scalar::Util::weaken $self; |
347 |
|
348 |
$self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub { |
349 |
delete $self->{_tw}; |
350 |
$self->_timeout; |
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}); |
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} else { |
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delete $self->{_tw}; |
354 |
} |
355 |
} |
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|
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############################################################################# |
358 |
|
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=back |
360 |
|
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=head2 WRITE QUEUE |
362 |
|
363 |
AnyEvent::Handle manages two queues per handle, one for writing and one |
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for reading. |
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|
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The write queue is very simple: you can add data to its end, and |
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AnyEvent::Handle will automatically try to get rid of it for you. |
368 |
|
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When data could be written and the write buffer is shorter then the low |
370 |
water mark, the C<on_drain> callback will be invoked. |
371 |
|
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=over 4 |
373 |
|
374 |
=item $handle->on_drain ($cb) |
375 |
|
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Sets the C<on_drain> callback or clears it (see the description of |
377 |
C<on_drain> in the constructor). |
378 |
|
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=cut |
380 |
|
381 |
sub on_drain { |
382 |
my ($self, $cb) = @_; |
383 |
|
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$self->{on_drain} = $cb; |
385 |
|
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$cb->($self) |
387 |
if $cb && $self->{low_water_mark} >= length $self->{wbuf}; |
388 |
} |
389 |
|
390 |
=item $handle->push_write ($data) |
391 |
|
392 |
Queues the given scalar to be written. You can push as much data as you |
393 |
want (only limited by the available memory), as C<AnyEvent::Handle> |
394 |
buffers it independently of the kernel. |
395 |
|
396 |
=cut |
397 |
|
398 |
sub _drain_wbuf { |
399 |
my ($self) = @_; |
400 |
|
401 |
if (!$self->{_ww} && length $self->{wbuf}) { |
402 |
|
403 |
Scalar::Util::weaken $self; |
404 |
|
405 |
my $cb = sub { |
406 |
my $len = syswrite $self->{fh}, $self->{wbuf}; |
407 |
|
408 |
if ($len >= 0) { |
409 |
substr $self->{wbuf}, 0, $len, ""; |
410 |
|
411 |
$self->{_activity} = AnyEvent->now; |
412 |
|
413 |
$self->{on_drain}($self) |
414 |
if $self->{low_water_mark} >= length $self->{wbuf} |
415 |
&& $self->{on_drain}; |
416 |
|
417 |
delete $self->{_ww} unless length $self->{wbuf}; |
418 |
} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { |
419 |
$self->error; |
420 |
} |
421 |
}; |
422 |
|
423 |
# try to write data immediately |
424 |
$cb->(); |
425 |
|
426 |
# if still data left in wbuf, we need to poll |
427 |
$self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb) |
428 |
if length $self->{wbuf}; |
429 |
}; |
430 |
} |
431 |
|
432 |
our %WH; |
433 |
|
434 |
sub register_write_type($$) { |
435 |
$WH{$_[0]} = $_[1]; |
436 |
} |
437 |
|
438 |
sub push_write { |
439 |
my $self = shift; |
440 |
|
441 |
if (@_ > 1) { |
442 |
my $type = shift; |
443 |
|
444 |
@_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") |
445 |
->($self, @_); |
446 |
} |
447 |
|
448 |
if ($self->{filter_w}) { |
449 |
$self->{filter_w}->($self, \$_[0]); |
450 |
} else { |
451 |
$self->{wbuf} .= $_[0]; |
452 |
$self->_drain_wbuf; |
453 |
} |
454 |
} |
455 |
|
456 |
=item $handle->push_write (type => @args) |
457 |
|
458 |
=item $handle->unshift_write (type => @args) |
459 |
|
460 |
Instead of formatting your data yourself, you can also let this module do |
461 |
the job by specifying a type and type-specific arguments. |
462 |
|
463 |
Predefined types are (if you have ideas for additional types, feel free to |
464 |
drop by and tell us): |
465 |
|
466 |
=over 4 |
467 |
|
468 |
=item netstring => $string |
469 |
|
470 |
Formats the given value as netstring |
471 |
(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). |
472 |
|
473 |
=back |
474 |
|
475 |
=cut |
476 |
|
477 |
register_write_type netstring => sub { |
478 |
my ($self, $string) = @_; |
479 |
|
480 |
sprintf "%d:%s,", (length $string), $string |
481 |
}; |
482 |
|
483 |
=item json => $array_or_hashref |
484 |
|
485 |
Encodes the given hash or array reference into a JSON object. Unless you |
486 |
provide your own JSON object, this means it will be encoded to JSON text |
487 |
in UTF-8. |
488 |
|
489 |
JSON objects (and arrays) are self-delimiting, so you can write JSON at |
490 |
one end of a handle and read them at the other end without using any |
491 |
additional framing. |
492 |
|
493 |
The generated JSON text is guaranteed not to contain any newlines: While |
494 |
this module doesn't need delimiters after or between JSON texts to be |
495 |
able to read them, many other languages depend on that. |
496 |
|
497 |
A simple RPC protocol that interoperates easily with others is to send |
498 |
JSON arrays (or objects, although arrays are usually the better choice as |
499 |
they mimic how function argument passing works) and a newline after each |
500 |
JSON text: |
501 |
|
502 |
$handle->push_write (json => ["method", "arg1", "arg2"]); # whatever |
503 |
$handle->push_write ("\012"); |
504 |
|
505 |
An AnyEvent::Handle receiver would simply use the C<json> read type and |
506 |
rely on the fact that the newline will be skipped as leading whitespace: |
507 |
|
508 |
$handle->push_read (json => sub { my $array = $_[1]; ... }); |
509 |
|
510 |
Other languages could read single lines terminated by a newline and pass |
511 |
this line into their JSON decoder of choice. |
512 |
|
513 |
=cut |
514 |
|
515 |
register_write_type json => sub { |
516 |
my ($self, $ref) = @_; |
517 |
|
518 |
require JSON; |
519 |
|
520 |
$self->{json} ? $self->{json}->encode ($ref) |
521 |
: JSON::encode_json ($ref) |
522 |
}; |
523 |
|
524 |
=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) |
525 |
|
526 |
This function (not method) lets you add your own types to C<push_write>. |
527 |
Whenever the given C<type> is used, C<push_write> will invoke the code |
528 |
reference with the handle object and the remaining arguments. |
529 |
|
530 |
The code reference is supposed to return a single octet string that will |
531 |
be appended to the write buffer. |
532 |
|
533 |
Note that this is a function, and all types registered this way will be |
534 |
global, so try to use unique names. |
535 |
|
536 |
=cut |
537 |
|
538 |
############################################################################# |
539 |
|
540 |
=back |
541 |
|
542 |
=head2 READ QUEUE |
543 |
|
544 |
AnyEvent::Handle manages two queues per handle, one for writing and one |
545 |
for reading. |
546 |
|
547 |
The read queue is more complex than the write queue. It can be used in two |
548 |
ways, the "simple" way, using only C<on_read> and the "complex" way, using |
549 |
a queue. |
550 |
|
551 |
In the simple case, you just install an C<on_read> callback and whenever |
552 |
new data arrives, it will be called. You can then remove some data (if |
553 |
enough is there) from the read buffer (C<< $handle->rbuf >>) if you want |
554 |
or not. |
555 |
|
556 |
In the more complex case, you want to queue multiple callbacks. In this |
557 |
case, AnyEvent::Handle will call the first queued callback each time new |
558 |
data arrives and removes it when it has done its job (see C<push_read>, |
559 |
below). |
560 |
|
561 |
This way you can, for example, push three line-reads, followed by reading |
562 |
a chunk of data, and AnyEvent::Handle will execute them in order. |
563 |
|
564 |
Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by |
565 |
the specified number of bytes which give an XML datagram. |
566 |
|
567 |
# in the default state, expect some header bytes |
568 |
$handle->on_read (sub { |
569 |
# some data is here, now queue the length-header-read (4 octets) |
570 |
shift->unshift_read_chunk (4, sub { |
571 |
# header arrived, decode |
572 |
my $len = unpack "N", $_[1]; |
573 |
|
574 |
# now read the payload |
575 |
shift->unshift_read_chunk ($len, sub { |
576 |
my $xml = $_[1]; |
577 |
# handle xml |
578 |
}); |
579 |
}); |
580 |
}); |
581 |
|
582 |
Example 2: Implement a client for a protocol that replies either with |
583 |
"OK" and another line or "ERROR" for one request, and 64 bytes for the |
584 |
second request. Due tot he availability of a full queue, we can just |
585 |
pipeline sending both requests and manipulate the queue as necessary in |
586 |
the callbacks: |
587 |
|
588 |
# request one |
589 |
$handle->push_write ("request 1\015\012"); |
590 |
|
591 |
# we expect "ERROR" or "OK" as response, so push a line read |
592 |
$handle->push_read_line (sub { |
593 |
# if we got an "OK", we have to _prepend_ another line, |
594 |
# so it will be read before the second request reads its 64 bytes |
595 |
# which are already in the queue when this callback is called |
596 |
# we don't do this in case we got an error |
597 |
if ($_[1] eq "OK") { |
598 |
$_[0]->unshift_read_line (sub { |
599 |
my $response = $_[1]; |
600 |
... |
601 |
}); |
602 |
} |
603 |
}); |
604 |
|
605 |
# request two |
606 |
$handle->push_write ("request 2\015\012"); |
607 |
|
608 |
# simply read 64 bytes, always |
609 |
$handle->push_read_chunk (64, sub { |
610 |
my $response = $_[1]; |
611 |
... |
612 |
}); |
613 |
|
614 |
=over 4 |
615 |
|
616 |
=cut |
617 |
|
618 |
sub _drain_rbuf { |
619 |
my ($self) = @_; |
620 |
|
621 |
if ( |
622 |
defined $self->{rbuf_max} |
623 |
&& $self->{rbuf_max} < length $self->{rbuf} |
624 |
) { |
625 |
$! = &Errno::ENOSPC; |
626 |
$self->error; |
627 |
} |
628 |
|
629 |
return if $self->{in_drain}; |
630 |
local $self->{in_drain} = 1; |
631 |
|
632 |
while (my $len = length $self->{rbuf}) { |
633 |
no strict 'refs'; |
634 |
if (my $cb = shift @{ $self->{_queue} }) { |
635 |
unless ($cb->($self)) { |
636 |
if ($self->{_eof}) { |
637 |
# no progress can be made (not enough data and no data forthcoming) |
638 |
$! = &Errno::EPIPE; |
639 |
$self->error; |
640 |
} |
641 |
|
642 |
unshift @{ $self->{_queue} }, $cb; |
643 |
return; |
644 |
} |
645 |
} elsif ($self->{on_read}) { |
646 |
$self->{on_read}($self); |
647 |
|
648 |
if ( |
649 |
$self->{_eof} # if no further data will arrive |
650 |
&& $len == length $self->{rbuf} # and no data has been consumed |
651 |
&& !@{ $self->{_queue} } # and the queue is still empty |
652 |
&& $self->{on_read} # and we still want to read data |
653 |
) { |
654 |
# then no progress can be made |
655 |
$! = &Errno::EPIPE; |
656 |
$self->error; |
657 |
} |
658 |
} else { |
659 |
# read side becomes idle |
660 |
delete $self->{_rw}; |
661 |
return; |
662 |
} |
663 |
} |
664 |
|
665 |
if ($self->{_eof}) { |
666 |
$self->_shutdown; |
667 |
$self->{on_eof}($self) |
668 |
if $self->{on_eof}; |
669 |
} |
670 |
} |
671 |
|
672 |
=item $handle->on_read ($cb) |
673 |
|
674 |
This replaces the currently set C<on_read> callback, or clears it (when |
675 |
the new callback is C<undef>). See the description of C<on_read> in the |
676 |
constructor. |
677 |
|
678 |
=cut |
679 |
|
680 |
sub on_read { |
681 |
my ($self, $cb) = @_; |
682 |
|
683 |
$self->{on_read} = $cb; |
684 |
} |
685 |
|
686 |
=item $handle->rbuf |
687 |
|
688 |
Returns the read buffer (as a modifiable lvalue). |
689 |
|
690 |
You can access the read buffer directly as the C<< ->{rbuf} >> member, if |
691 |
you want. |
692 |
|
693 |
NOTE: The read buffer should only be used or modified if the C<on_read>, |
694 |
C<push_read> or C<unshift_read> methods are used. The other read methods |
695 |
automatically manage the read buffer. |
696 |
|
697 |
=cut |
698 |
|
699 |
sub rbuf : lvalue { |
700 |
$_[0]{rbuf} |
701 |
} |
702 |
|
703 |
=item $handle->push_read ($cb) |
704 |
|
705 |
=item $handle->unshift_read ($cb) |
706 |
|
707 |
Append the given callback to the end of the queue (C<push_read>) or |
708 |
prepend it (C<unshift_read>). |
709 |
|
710 |
The callback is called each time some additional read data arrives. |
711 |
|
712 |
It must check whether enough data is in the read buffer already. |
713 |
|
714 |
If not enough data is available, it must return the empty list or a false |
715 |
value, in which case it will be called repeatedly until enough data is |
716 |
available (or an error condition is detected). |
717 |
|
718 |
If enough data was available, then the callback must remove all data it is |
719 |
interested in (which can be none at all) and return a true value. After returning |
720 |
true, it will be removed from the queue. |
721 |
|
722 |
=cut |
723 |
|
724 |
our %RH; |
725 |
|
726 |
sub register_read_type($$) { |
727 |
$RH{$_[0]} = $_[1]; |
728 |
} |
729 |
|
730 |
sub push_read { |
731 |
my $self = shift; |
732 |
my $cb = pop; |
733 |
|
734 |
if (@_) { |
735 |
my $type = shift; |
736 |
|
737 |
$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") |
738 |
->($self, $cb, @_); |
739 |
} |
740 |
|
741 |
push @{ $self->{_queue} }, $cb; |
742 |
$self->_drain_rbuf; |
743 |
} |
744 |
|
745 |
sub unshift_read { |
746 |
my $self = shift; |
747 |
my $cb = pop; |
748 |
|
749 |
if (@_) { |
750 |
my $type = shift; |
751 |
|
752 |
$cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") |
753 |
->($self, $cb, @_); |
754 |
} |
755 |
|
756 |
|
757 |
unshift @{ $self->{_queue} }, $cb; |
758 |
$self->_drain_rbuf; |
759 |
} |
760 |
|
761 |
=item $handle->push_read (type => @args, $cb) |
762 |
|
763 |
=item $handle->unshift_read (type => @args, $cb) |
764 |
|
765 |
Instead of providing a callback that parses the data itself you can chose |
766 |
between a number of predefined parsing formats, for chunks of data, lines |
767 |
etc. |
768 |
|
769 |
Predefined types are (if you have ideas for additional types, feel free to |
770 |
drop by and tell us): |
771 |
|
772 |
=over 4 |
773 |
|
774 |
=item chunk => $octets, $cb->($handle, $data) |
775 |
|
776 |
Invoke the callback only once C<$octets> bytes have been read. Pass the |
777 |
data read to the callback. The callback will never be called with less |
778 |
data. |
779 |
|
780 |
Example: read 2 bytes. |
781 |
|
782 |
$handle->push_read (chunk => 2, sub { |
783 |
warn "yay ", unpack "H*", $_[1]; |
784 |
}); |
785 |
|
786 |
=cut |
787 |
|
788 |
register_read_type chunk => sub { |
789 |
my ($self, $cb, $len) = @_; |
790 |
|
791 |
sub { |
792 |
$len <= length $_[0]{rbuf} or return; |
793 |
$cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); |
794 |
1 |
795 |
} |
796 |
}; |
797 |
|
798 |
# compatibility with older API |
799 |
sub push_read_chunk { |
800 |
$_[0]->push_read (chunk => $_[1], $_[2]); |
801 |
} |
802 |
|
803 |
sub unshift_read_chunk { |
804 |
$_[0]->unshift_read (chunk => $_[1], $_[2]); |
805 |
} |
806 |
|
807 |
=item line => [$eol, ]$cb->($handle, $line, $eol) |
808 |
|
809 |
The callback will be called only once a full line (including the end of |
810 |
line marker, C<$eol>) has been read. This line (excluding the end of line |
811 |
marker) will be passed to the callback as second argument (C<$line>), and |
812 |
the end of line marker as the third argument (C<$eol>). |
813 |
|
814 |
The end of line marker, C<$eol>, can be either a string, in which case it |
815 |
will be interpreted as a fixed record end marker, or it can be a regex |
816 |
object (e.g. created by C<qr>), in which case it is interpreted as a |
817 |
regular expression. |
818 |
|
819 |
The end of line marker argument C<$eol> is optional, if it is missing (NOT |
820 |
undef), then C<qr|\015?\012|> is used (which is good for most internet |
821 |
protocols). |
822 |
|
823 |
Partial lines at the end of the stream will never be returned, as they are |
824 |
not marked by the end of line marker. |
825 |
|
826 |
=cut |
827 |
|
828 |
register_read_type line => sub { |
829 |
my ($self, $cb, $eol) = @_; |
830 |
|
831 |
$eol = qr|(\015?\012)| if @_ < 3; |
832 |
$eol = quotemeta $eol unless ref $eol; |
833 |
$eol = qr|^(.*?)($eol)|s; |
834 |
|
835 |
sub { |
836 |
$_[0]{rbuf} =~ s/$eol// or return; |
837 |
|
838 |
$cb->($_[0], $1, $2); |
839 |
1 |
840 |
} |
841 |
}; |
842 |
|
843 |
# compatibility with older API |
844 |
sub push_read_line { |
845 |
my $self = shift; |
846 |
$self->push_read (line => @_); |
847 |
} |
848 |
|
849 |
sub unshift_read_line { |
850 |
my $self = shift; |
851 |
$self->unshift_read (line => @_); |
852 |
} |
853 |
|
854 |
=item netstring => $cb->($handle, $string) |
855 |
|
856 |
A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). |
857 |
|
858 |
Throws an error with C<$!> set to EBADMSG on format violations. |
859 |
|
860 |
=cut |
861 |
|
862 |
register_read_type netstring => sub { |
863 |
my ($self, $cb) = @_; |
864 |
|
865 |
sub { |
866 |
unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { |
867 |
if ($_[0]{rbuf} =~ /[^0-9]/) { |
868 |
$! = &Errno::EBADMSG; |
869 |
$self->error; |
870 |
} |
871 |
return; |
872 |
} |
873 |
|
874 |
my $len = $1; |
875 |
|
876 |
$self->unshift_read (chunk => $len, sub { |
877 |
my $string = $_[1]; |
878 |
$_[0]->unshift_read (chunk => 1, sub { |
879 |
if ($_[1] eq ",") { |
880 |
$cb->($_[0], $string); |
881 |
} else { |
882 |
$! = &Errno::EBADMSG; |
883 |
$self->error; |
884 |
} |
885 |
}); |
886 |
}); |
887 |
|
888 |
1 |
889 |
} |
890 |
}; |
891 |
|
892 |
=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) |
893 |
|
894 |
Makes a regex match against the regex object C<$accept> and returns |
895 |
everything up to and including the match. |
896 |
|
897 |
Example: read a single line terminated by '\n'. |
898 |
|
899 |
$handle->push_read (regex => qr<\n>, sub { ... }); |
900 |
|
901 |
If C<$reject> is given and not undef, then it determines when the data is |
902 |
to be rejected: it is matched against the data when the C<$accept> regex |
903 |
does not match and generates an C<EBADMSG> error when it matches. This is |
904 |
useful to quickly reject wrong data (to avoid waiting for a timeout or a |
905 |
receive buffer overflow). |
906 |
|
907 |
Example: expect a single decimal number followed by whitespace, reject |
908 |
anything else (not the use of an anchor). |
909 |
|
910 |
$handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... }); |
911 |
|
912 |
If C<$skip> is given and not C<undef>, then it will be matched against |
913 |
the receive buffer when neither C<$accept> nor C<$reject> match, |
914 |
and everything preceding and including the match will be accepted |
915 |
unconditionally. This is useful to skip large amounts of data that you |
916 |
know cannot be matched, so that the C<$accept> or C<$reject> regex do not |
917 |
have to start matching from the beginning. This is purely an optimisation |
918 |
and is usually worth only when you expect more than a few kilobytes. |
919 |
|
920 |
Example: expect a http header, which ends at C<\015\012\015\012>. Since we |
921 |
expect the header to be very large (it isn't in practise, but...), we use |
922 |
a skip regex to skip initial portions. The skip regex is tricky in that |
923 |
it only accepts something not ending in either \015 or \012, as these are |
924 |
required for the accept regex. |
925 |
|
926 |
$handle->push_read (regex => |
927 |
qr<\015\012\015\012>, |
928 |
undef, # no reject |
929 |
qr<^.*[^\015\012]>, |
930 |
sub { ... }); |
931 |
|
932 |
=cut |
933 |
|
934 |
register_read_type regex => sub { |
935 |
my ($self, $cb, $accept, $reject, $skip) = @_; |
936 |
|
937 |
my $data; |
938 |
my $rbuf = \$self->{rbuf}; |
939 |
|
940 |
sub { |
941 |
# accept |
942 |
if ($$rbuf =~ $accept) { |
943 |
$data .= substr $$rbuf, 0, $+[0], ""; |
944 |
$cb->($self, $data); |
945 |
return 1; |
946 |
} |
947 |
|
948 |
# reject |
949 |
if ($reject && $$rbuf =~ $reject) { |
950 |
$! = &Errno::EBADMSG; |
951 |
$self->error; |
952 |
} |
953 |
|
954 |
# skip |
955 |
if ($skip && $$rbuf =~ $skip) { |
956 |
$data .= substr $$rbuf, 0, $+[0], ""; |
957 |
} |
958 |
|
959 |
() |
960 |
} |
961 |
}; |
962 |
|
963 |
=item json => $cb->($handle, $hash_or_arrayref) |
964 |
|
965 |
Reads a JSON object or array, decodes it and passes it to the callback. |
966 |
|
967 |
If a C<json> object was passed to the constructor, then that will be used |
968 |
for the final decode, otherwise it will create a JSON coder expecting UTF-8. |
969 |
|
970 |
This read type uses the incremental parser available with JSON version |
971 |
2.09 (and JSON::XS version 2.2) and above. You have to provide a |
972 |
dependency on your own: this module will load the JSON module, but |
973 |
AnyEvent does not depend on it itself. |
974 |
|
975 |
Since JSON texts are fully self-delimiting, the C<json> read and write |
976 |
types are an ideal simple RPC protocol: just exchange JSON datagrams. See |
977 |
the C<json> write type description, above, for an actual example. |
978 |
|
979 |
=cut |
980 |
|
981 |
register_read_type json => sub { |
982 |
my ($self, $cb, $accept, $reject, $skip) = @_; |
983 |
|
984 |
require JSON; |
985 |
|
986 |
my $data; |
987 |
my $rbuf = \$self->{rbuf}; |
988 |
|
989 |
my $json = $self->{json} ||= JSON->new->utf8; |
990 |
|
991 |
sub { |
992 |
my $ref = $json->incr_parse ($self->{rbuf}); |
993 |
|
994 |
if ($ref) { |
995 |
$self->{rbuf} = $json->incr_text; |
996 |
$json->incr_text = ""; |
997 |
$cb->($self, $ref); |
998 |
|
999 |
1 |
1000 |
} else { |
1001 |
$self->{rbuf} = ""; |
1002 |
() |
1003 |
} |
1004 |
} |
1005 |
}; |
1006 |
|
1007 |
=back |
1008 |
|
1009 |
=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) |
1010 |
|
1011 |
This function (not method) lets you add your own types to C<push_read>. |
1012 |
|
1013 |
Whenever the given C<type> is used, C<push_read> will invoke the code |
1014 |
reference with the handle object, the callback and the remaining |
1015 |
arguments. |
1016 |
|
1017 |
The code reference is supposed to return a callback (usually a closure) |
1018 |
that works as a plain read callback (see C<< ->push_read ($cb) >>). |
1019 |
|
1020 |
It should invoke the passed callback when it is done reading (remember to |
1021 |
pass C<$handle> as first argument as all other callbacks do that). |
1022 |
|
1023 |
Note that this is a function, and all types registered this way will be |
1024 |
global, so try to use unique names. |
1025 |
|
1026 |
For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, |
1027 |
search for C<register_read_type>)). |
1028 |
|
1029 |
=item $handle->stop_read |
1030 |
|
1031 |
=item $handle->start_read |
1032 |
|
1033 |
In rare cases you actually do not want to read anything from the |
1034 |
socket. In this case you can call C<stop_read>. Neither C<on_read> no |
1035 |
any queued callbacks will be executed then. To start reading again, call |
1036 |
C<start_read>. |
1037 |
|
1038 |
=cut |
1039 |
|
1040 |
sub stop_read { |
1041 |
my ($self) = @_; |
1042 |
|
1043 |
delete $self->{_rw}; |
1044 |
} |
1045 |
|
1046 |
sub start_read { |
1047 |
my ($self) = @_; |
1048 |
|
1049 |
unless ($self->{_rw} || $self->{_eof}) { |
1050 |
Scalar::Util::weaken $self; |
1051 |
|
1052 |
$self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { |
1053 |
my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; |
1054 |
my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; |
1055 |
|
1056 |
if ($len > 0) { |
1057 |
$self->{_activity} = AnyEvent->now; |
1058 |
|
1059 |
$self->{filter_r} |
1060 |
? $self->{filter_r}->($self, $rbuf) |
1061 |
: $self->_drain_rbuf; |
1062 |
|
1063 |
} elsif (defined $len) { |
1064 |
delete $self->{_rw}; |
1065 |
delete $self->{_ww}; |
1066 |
delete $self->{_tw}; |
1067 |
$self->{_eof} = 1; |
1068 |
$self->_drain_rbuf; |
1069 |
|
1070 |
} elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { |
1071 |
return $self->error; |
1072 |
} |
1073 |
}); |
1074 |
} |
1075 |
} |
1076 |
|
1077 |
sub _dotls { |
1078 |
my ($self) = @_; |
1079 |
|
1080 |
if (length $self->{_tls_wbuf}) { |
1081 |
while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { |
1082 |
substr $self->{_tls_wbuf}, 0, $len, ""; |
1083 |
} |
1084 |
} |
1085 |
|
1086 |
if (defined (my $buf = Net::SSLeay::BIO_read ($self->{_wbio}))) { |
1087 |
$self->{wbuf} .= $buf; |
1088 |
$self->_drain_wbuf; |
1089 |
} |
1090 |
|
1091 |
while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) { |
1092 |
$self->{rbuf} .= $buf; |
1093 |
$self->_drain_rbuf; |
1094 |
} |
1095 |
|
1096 |
my $err = Net::SSLeay::get_error ($self->{tls}, -1); |
1097 |
|
1098 |
if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { |
1099 |
if ($err == Net::SSLeay::ERROR_SYSCALL ()) { |
1100 |
$self->error; |
1101 |
} elsif ($err == Net::SSLeay::ERROR_SSL ()) { |
1102 |
$! = &Errno::EIO; |
1103 |
$self->error; |
1104 |
} |
1105 |
|
1106 |
# all others are fine for our purposes |
1107 |
} |
1108 |
} |
1109 |
|
1110 |
=item $handle->starttls ($tls[, $tls_ctx]) |
1111 |
|
1112 |
Instead of starting TLS negotiation immediately when the AnyEvent::Handle |
1113 |
object is created, you can also do that at a later time by calling |
1114 |
C<starttls>. |
1115 |
|
1116 |
The first argument is the same as the C<tls> constructor argument (either |
1117 |
C<"connect">, C<"accept"> or an existing Net::SSLeay object). |
1118 |
|
1119 |
The second argument is the optional C<Net::SSLeay::CTX> object that is |
1120 |
used when AnyEvent::Handle has to create its own TLS connection object. |
1121 |
|
1122 |
The TLS connection object will end up in C<< $handle->{tls} >> after this |
1123 |
call and can be used or changed to your liking. Note that the handshake |
1124 |
might have already started when this function returns. |
1125 |
|
1126 |
=cut |
1127 |
|
1128 |
# TODO: maybe document... |
1129 |
sub starttls { |
1130 |
my ($self, $ssl, $ctx) = @_; |
1131 |
|
1132 |
$self->stoptls; |
1133 |
|
1134 |
if ($ssl eq "accept") { |
1135 |
$ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); |
1136 |
Net::SSLeay::set_accept_state ($ssl); |
1137 |
} elsif ($ssl eq "connect") { |
1138 |
$ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); |
1139 |
Net::SSLeay::set_connect_state ($ssl); |
1140 |
} |
1141 |
|
1142 |
$self->{tls} = $ssl; |
1143 |
|
1144 |
# basically, this is deep magic (because SSL_read should have the same issues) |
1145 |
# but the openssl maintainers basically said: "trust us, it just works". |
1146 |
# (unfortunately, we have to hardcode constants because the abysmally misdesigned |
1147 |
# and mismaintained ssleay-module doesn't even offer them). |
1148 |
# http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html |
1149 |
Net::SSLeay::CTX_set_mode ($self->{tls}, |
1150 |
(eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) |
1151 |
| (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); |
1152 |
|
1153 |
$self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); |
1154 |
$self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); |
1155 |
|
1156 |
Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); |
1157 |
|
1158 |
$self->{filter_w} = sub { |
1159 |
$_[0]{_tls_wbuf} .= ${$_[1]}; |
1160 |
&_dotls; |
1161 |
}; |
1162 |
$self->{filter_r} = sub { |
1163 |
Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]}); |
1164 |
&_dotls; |
1165 |
}; |
1166 |
} |
1167 |
|
1168 |
=item $handle->stoptls |
1169 |
|
1170 |
Destroys the SSL connection, if any. Partial read or write data will be |
1171 |
lost. |
1172 |
|
1173 |
=cut |
1174 |
|
1175 |
sub stoptls { |
1176 |
my ($self) = @_; |
1177 |
|
1178 |
Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; |
1179 |
|
1180 |
delete $self->{_rbio}; |
1181 |
delete $self->{_wbio}; |
1182 |
delete $self->{_tls_wbuf}; |
1183 |
delete $self->{filter_r}; |
1184 |
delete $self->{filter_w}; |
1185 |
} |
1186 |
|
1187 |
sub DESTROY { |
1188 |
my $self = shift; |
1189 |
|
1190 |
$self->stoptls; |
1191 |
} |
1192 |
|
1193 |
=item AnyEvent::Handle::TLS_CTX |
1194 |
|
1195 |
This function creates and returns the Net::SSLeay::CTX object used by |
1196 |
default for TLS mode. |
1197 |
|
1198 |
The context is created like this: |
1199 |
|
1200 |
Net::SSLeay::load_error_strings; |
1201 |
Net::SSLeay::SSLeay_add_ssl_algorithms; |
1202 |
Net::SSLeay::randomize; |
1203 |
|
1204 |
my $CTX = Net::SSLeay::CTX_new; |
1205 |
|
1206 |
Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL |
1207 |
|
1208 |
=cut |
1209 |
|
1210 |
our $TLS_CTX; |
1211 |
|
1212 |
sub TLS_CTX() { |
1213 |
$TLS_CTX || do { |
1214 |
require Net::SSLeay; |
1215 |
|
1216 |
Net::SSLeay::load_error_strings (); |
1217 |
Net::SSLeay::SSLeay_add_ssl_algorithms (); |
1218 |
Net::SSLeay::randomize (); |
1219 |
|
1220 |
$TLS_CTX = Net::SSLeay::CTX_new (); |
1221 |
|
1222 |
Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ()); |
1223 |
|
1224 |
$TLS_CTX |
1225 |
} |
1226 |
} |
1227 |
|
1228 |
=back |
1229 |
|
1230 |
=head1 SUBCLASSING AnyEvent::Handle |
1231 |
|
1232 |
In many cases, you might want to subclass AnyEvent::Handle. |
1233 |
|
1234 |
To make this easier, a given version of AnyEvent::Handle uses these |
1235 |
conventions: |
1236 |
|
1237 |
=over 4 |
1238 |
|
1239 |
=item * all constructor arguments become object members. |
1240 |
|
1241 |
At least initially, when you pass a C<tls>-argument to the constructor it |
1242 |
will end up in C<< $handle->{tls} >>. Those members might be changes or |
1243 |
mutated later on (for example C<tls> will hold the TLS connection object). |
1244 |
|
1245 |
=item * other object member names are prefixed with an C<_>. |
1246 |
|
1247 |
All object members not explicitly documented (internal use) are prefixed |
1248 |
with an underscore character, so the remaining non-C<_>-namespace is free |
1249 |
for use for subclasses. |
1250 |
|
1251 |
=item * all members not documented here and not prefixed with an underscore |
1252 |
are free to use in subclasses. |
1253 |
|
1254 |
Of course, new versions of AnyEvent::Handle may introduce more "public" |
1255 |
member variables, but thats just life, at least it is documented. |
1256 |
|
1257 |
=back |
1258 |
|
1259 |
=head1 AUTHOR |
1260 |
|
1261 |
Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. |
1262 |
|
1263 |
=cut |
1264 |
|
1265 |
1; # End of AnyEvent::Handle |