| 1 |
=head1 NAME |
| 2 |
|
| 3 |
Coro::Handle - non-blocking io with a blocking interface. |
| 4 |
|
| 5 |
=head1 SYNOPSIS |
| 6 |
|
| 7 |
use Coro::Handle; |
| 8 |
|
| 9 |
=head1 DESCRIPTION |
| 10 |
|
| 11 |
This module implements IO-handles in a coroutine-compatible way, that is, |
| 12 |
other coroutines can run while reads or writes block on the handle. |
| 13 |
|
| 14 |
It does so by using L<AnyEvent|AnyEvent> to wait for readable/writable |
| 15 |
data, allowing other coroutines to run while one coroutine waits for I/O. |
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|
| 17 |
Coro::Handle does NOT inherit from IO::Handle but uses tied objects. |
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|
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=over 4 |
| 20 |
|
| 21 |
=cut |
| 22 |
|
| 23 |
package Coro::Handle; |
| 24 |
|
| 25 |
no warnings; |
| 26 |
use strict; |
| 27 |
|
| 28 |
use Carp (); |
| 29 |
use Errno (); |
| 30 |
use base 'Exporter'; |
| 31 |
|
| 32 |
our $VERSION = 2.5; |
| 33 |
our @EXPORT = qw(unblock); |
| 34 |
|
| 35 |
=item $fh = new_from_fh Coro::Handle $fhandle [, arg => value...] |
| 36 |
|
| 37 |
Create a new non-blocking io-handle using the given |
| 38 |
perl-filehandle. Returns undef if no fhandle is given. The only other |
| 39 |
supported argument is "timeout", which sets a timeout for each operation. |
| 40 |
|
| 41 |
=cut |
| 42 |
|
| 43 |
sub new_from_fh { |
| 44 |
my $class = shift; |
| 45 |
my $fh = shift or return; |
| 46 |
my $self = do { local *Coro::Handle }; |
| 47 |
|
| 48 |
my ($package, $filename, $line) = caller; |
| 49 |
$filename =~ s/^.*[\/\\]//; |
| 50 |
|
| 51 |
tie $self, 'Coro::Handle::FH', fh => $fh, desc => "$filename:$line", @_; |
| 52 |
|
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my $_fh = select bless \$self, ref $class ? ref $class : $class; $| = 1; select $_fh; |
| 54 |
} |
| 55 |
|
| 56 |
=item $fh = unblock $fh |
| 57 |
|
| 58 |
This is a convinience function that just calls C<new_from_fh> on the given |
| 59 |
filehandle. Use it to replace a normal perl filehandle by a non-blocking |
| 60 |
equivalent. |
| 61 |
|
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=cut |
| 63 |
|
| 64 |
sub unblock($) { |
| 65 |
new_from_fh Coro::Handle $_[0]; |
| 66 |
} |
| 67 |
|
| 68 |
=item $fh->writable, $fh->readable |
| 69 |
|
| 70 |
Wait until the filehandle is readable or writable (and return true) or |
| 71 |
until an error condition happens (and return false). |
| 72 |
|
| 73 |
=cut |
| 74 |
|
| 75 |
sub readable { Coro::Handle::FH::readable (tied ${$_[0]}) } |
| 76 |
sub writable { Coro::Handle::FH::writable (tied ${$_[0]}) } |
| 77 |
|
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=item $fh->readline ([$terminator]) |
| 79 |
|
| 80 |
Like the builtin of the same name, but allows you to specify the input |
| 81 |
record separator in a coroutine-safe manner (i.e. not using a global |
| 82 |
variable). |
| 83 |
|
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=cut |
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|
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sub readline { tied(${+shift})->READLINE(@_) } |
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|
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=item $fh->autoflush ([...]) |
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|
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Always returns true, arguments are being ignored (exists for compatibility |
| 91 |
only). Might change in the future. |
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|
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=cut |
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|
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sub autoflush { !0 } |
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|
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=item $fh->fileno, $fh->close, $fh->read, $fh->sysread, $fh->syswrite, $fh->print, $fh->printf |
| 98 |
|
| 99 |
Work like their function equivalents (except read, which works like |
| 100 |
sysread. You should not use the read function with Coro::Handles, it will |
| 101 |
work but it's not efficient). |
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|
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=cut |
| 104 |
|
| 105 |
sub read { Coro::Handle::FH::READ (tied ${$_[0]}, $_[1], $_[2], $_[3]) } |
| 106 |
sub sysread { Coro::Handle::FH::READ (tied ${$_[0]}, $_[1], $_[2], $_[3]) } |
| 107 |
sub syswrite { Coro::Handle::FH::WRITE (tied ${$_[0]}, $_[1], $_[2], $_[3]) } |
| 108 |
sub print { Coro::Handle::FH::WRITE (tied ${+shift}, join "", @_) } |
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sub printf { Coro::Handle::FH::PRINTF (tied ${+shift}, @_) } |
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sub fileno { Coro::Handle::FH::FILENO (tied ${$_[0]}) } |
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sub close { Coro::Handle::FH::CLOSE (tied ${$_[0]}) } |
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sub blocking { !0 } # this handler always blocks the caller |
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|
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sub partial { |
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my $obj = tied ${$_[0]}; |
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|
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my $retval = $obj->[8]; |
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$obj->[8] = $_[1] if @_ > 1; |
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$retval |
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} |
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|
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=item $fh->timeout([...]) |
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|
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The optional argument sets the new timeout (in seconds) for this |
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handle. Returns the current (new) value. |
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|
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C<0> is a valid timeout, use C<undef> to disable the timeout. |
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|
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=cut |
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|
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sub timeout { |
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my $self = tied(${$_[0]}); |
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if (@_ > 1) { |
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$self->[2] = $_[1]; |
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$self->[5]->timeout($_[1]) if $self->[5]; |
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$self->[6]->timeout($_[1]) if $self->[6]; |
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} |
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$self->[2]; |
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} |
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|
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=item $fh->fh |
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|
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Returns the "real" (non-blocking) filehandle. Use this if you want to |
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do operations on the file handle you cannot do using the Coro::Handle |
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interface. |
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|
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=item $fh->rbuf |
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|
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Returns the current contents of the read buffer (this is an lvalue, so you |
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can change the read buffer if you like). |
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|
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You can use this function to implement your own optimized reader when neither |
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readline nor sysread are viable candidates, like this: |
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|
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# first get the _real_ non-blocking filehandle |
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# and fetch a reference to the read buffer |
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my $nb_fh = $fh->fh; |
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my $buf = \$fh->rbuf; |
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|
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for(;;) { |
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# now use buffer contents, modifying |
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# if necessary to reflect the removed data |
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|
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last if $$buf ne ""; # we have leftover data |
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|
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# read another buffer full of data |
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$fh->readable or die "end of file"; |
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sysread $nb_fh, $$buf, 8192; |
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} |
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|
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=cut |
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|
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sub fh { |
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(tied ${$_[0]})->[0]; |
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} |
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|
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sub rbuf : lvalue { |
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(tied ${$_[0]})->[3]; |
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} |
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|
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sub DESTROY { |
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# nop |
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} |
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|
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our $AUTOLOAD; |
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|
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sub AUTOLOAD { |
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my $self = tied ${$_[0]}; |
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|
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(my $func = $AUTOLOAD) =~ s/^(.*):://; |
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|
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my $forward = UNIVERSAL::can $self->[7], $func; |
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|
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$forward or |
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die "Can't locate object method \"$func\" via package \"" . (ref $self) . "\""; |
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|
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goto &$forward; |
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} |
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|
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package Coro::Handle::FH; |
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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 Fcntl (); |
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use Errno (); |
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use Carp 'croak'; |
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|
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use AnyEvent; |
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|
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# formerly a hash, but we are speed-critical, so try |
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# to be faster even if it hurts. |
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# |
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# 0 FH |
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# 1 desc |
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# 2 timeout |
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# 3 rb |
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# 4 wb # unused |
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# 5 unused |
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# 6 unused |
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# 7 forward class |
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# 8 blocking |
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|
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sub TIEHANDLE { |
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my ($class, %arg) = @_; |
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|
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my $self = bless [], $class; |
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$self->[0] = $arg{fh}; |
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$self->[1] = $arg{desc}; |
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$self->[2] = $arg{timeout}; |
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$self->[3] = ""; |
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$self->[4] = ""; |
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$self->[7] = $arg{forward_class}; |
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$self->[8] = $arg{partial}; |
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|
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fcntl $self->[0], &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK |
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or croak "fcntl(O_NONBLOCK): $!"; |
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|
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$self |
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} |
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|
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sub cleanup { |
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$_[0][3] = ""; |
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$_[0][4] = ""; |
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} |
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|
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sub OPEN { |
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&cleanup; |
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my $self = shift; |
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my $r = @_ == 2 ? open $self->[0], $_[0], $_[1] |
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: open $self->[0], $_[0], $_[1], $_[2]; |
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if ($r) { |
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fcntl $self->[0], &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK |
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or croak "fcntl(O_NONBLOCK): $!"; |
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} |
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$r; |
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} |
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|
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sub PRINT { |
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WRITE (shift, join "", @_); |
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} |
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|
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sub PRINTF { |
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WRITE (shift, sprintf shift,@_); |
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} |
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|
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sub GETC { |
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my $buf; |
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READ ($_[0], $buf, 1); |
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$buf; |
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} |
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|
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sub BINMODE { |
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binmode $_[0][0]; |
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} |
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|
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sub TELL { |
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Carp::croak "Coro::Handle's don't support tell()"; |
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} |
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|
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sub SEEK { |
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Carp::croak "Coro::Handle's don't support seek()"; |
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} |
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|
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sub EOF { |
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Carp::croak "Coro::Handle's don't support eof()"; |
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} |
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|
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sub CLOSE { |
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&cleanup; |
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close $_[0][0]; |
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} |
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|
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sub DESTROY { |
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&cleanup; |
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} |
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|
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sub FILENO { |
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fileno $_[0][0]; |
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} |
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|
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# seems to be called for stringification (how weird), at least |
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# when DumpValue::dumpValue is used to print this. |
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sub FETCH { |
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"$_[0]<$_[0][1]>"; |
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} |
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|
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sub readable { |
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my $current = $Coro::current; |
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my $io = 1; |
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|
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my $w = AnyEvent->io ( |
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desc => "$_[0][1] read watcher", |
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fh => $_[0][0], |
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poll => 'r', |
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cb => sub { |
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$current->ready; |
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undef $current; |
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}, |
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); |
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|
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my $t = (defined $_[0][2]) && AnyEvent->timer ( |
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desc => "fh $_[0][1] read timeout", |
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after => $_[0][2], |
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cb => sub { |
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$io = 0; |
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$current->ready; |
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undef $current; |
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}, |
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); |
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|
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&Coro::schedule; |
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&Coro::schedule while $current; |
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|
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$io |
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} |
| 337 |
|
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sub writable { |
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my $current = $Coro::current; |
| 340 |
my $io = 1; |
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|
| 342 |
my $w = AnyEvent->io ( |
| 343 |
desc => "fh $_[0][1] write watcher", |
| 344 |
fh => $_[0][0], |
| 345 |
poll => 'w', |
| 346 |
cb => sub { |
| 347 |
$current->ready; |
| 348 |
undef $current; |
| 349 |
}, |
| 350 |
); |
| 351 |
|
| 352 |
my $t = (defined $_[0][2]) && AnyEvent->timer ( |
| 353 |
desc => "fh $_[0][1] write timeout", |
| 354 |
after => $_[0][2], |
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cb => sub { |
| 356 |
$io = 0; |
| 357 |
$current->ready; |
| 358 |
undef $current; |
| 359 |
}, |
| 360 |
); |
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|
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&Coro::schedule while $current; |
| 363 |
|
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$io |
| 365 |
} |
| 366 |
|
| 367 |
sub WRITE { |
| 368 |
my $len = defined $_[2] ? $_[2] : length $_[1]; |
| 369 |
my $ofs = $_[3]; |
| 370 |
my $res = 0; |
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|
| 372 |
while () { |
| 373 |
my $r = syswrite ($_[0][0], $_[1], $len, $ofs); |
| 374 |
if (defined $r) { |
| 375 |
$len -= $r; |
| 376 |
$ofs += $r; |
| 377 |
$res += $r; |
| 378 |
last unless $len; |
| 379 |
} elsif ($! != Errno::EAGAIN) { |
| 380 |
last; |
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} |
| 382 |
last unless &writable; |
| 383 |
} |
| 384 |
|
| 385 |
return $res; |
| 386 |
} |
| 387 |
|
| 388 |
sub READ { |
| 389 |
my $len = $_[2]; |
| 390 |
my $ofs = $_[3]; |
| 391 |
my $res = 0; |
| 392 |
|
| 393 |
# first deplete the read buffer |
| 394 |
if (length $_[0][3]) { |
| 395 |
my $l = length $_[0][3]; |
| 396 |
if ($l <= $len) { |
| 397 |
substr($_[1], $ofs) = $_[0][3]; $_[0][3] = ""; |
| 398 |
$len -= $l; |
| 399 |
$ofs += $l; |
| 400 |
$res += $l; |
| 401 |
return $res unless $len; |
| 402 |
} else { |
| 403 |
substr($_[1], $ofs) = substr($_[0][3], 0, $len); |
| 404 |
substr($_[0][3], 0, $len) = ""; |
| 405 |
return $len; |
| 406 |
} |
| 407 |
} |
| 408 |
|
| 409 |
while() { |
| 410 |
my $r = sysread $_[0][0], $_[1], $len, $ofs; |
| 411 |
if (defined $r) { |
| 412 |
$len -= $r; |
| 413 |
$ofs += $r; |
| 414 |
$res += $r; |
| 415 |
last unless $len && $r; |
| 416 |
} elsif ($! != Errno::EAGAIN) { |
| 417 |
last; |
| 418 |
} |
| 419 |
last if $_[0][8] || !&readable; |
| 420 |
} |
| 421 |
|
| 422 |
return $res; |
| 423 |
} |
| 424 |
|
| 425 |
sub READLINE { |
| 426 |
my $irs = @_ > 1 ? $_[1] : $/; |
| 427 |
|
| 428 |
while() { |
| 429 |
my $pos = index $_[0][3], $irs; |
| 430 |
if ($pos >= 0) { |
| 431 |
$pos += length $irs; |
| 432 |
my $res = substr $_[0][3], 0, $pos; |
| 433 |
substr ($_[0][3], 0, $pos) = ""; |
| 434 |
return $res; |
| 435 |
} |
| 436 |
|
| 437 |
my $r = sysread $_[0][0], $_[0][3], 8192, length $_[0][3]; |
| 438 |
if (defined $r) { |
| 439 |
return undef unless $r; |
| 440 |
} elsif ($! != Errno::EAGAIN || !&readable) { |
| 441 |
return undef; |
| 442 |
} |
| 443 |
} |
| 444 |
} |
| 445 |
|
| 446 |
1; |
| 447 |
|
| 448 |
=back |
| 449 |
|
| 450 |
=head1 BUGS |
| 451 |
|
| 452 |
- Perl's IO-Handle model is THE bug. |
| 453 |
|
| 454 |
=head1 AUTHOR |
| 455 |
|
| 456 |
Marc Lehmann <schmorp@schmorp.de> |
| 457 |
http://home.schmorp.de/ |
| 458 |
|
| 459 |
=cut |
| 460 |
|
