CHI::CacheObject - Contains information about cache entries

    my $object = $cache->get_object($key);

    my $key        = $object->key();
    my $value      = $object->value();
    my $expires_at = $object->expires_at();
    my $created_at = $object->created_at();

    if ($object->is_expired()) { ... }

package CHI::CacheObject;
BEGIN {
  $CHI::CacheObject::VERSION = '0.49';
}
use CHI::Constants qw(CHI_Max_Time);
use Encode;
use strict;
use warnings;

use constant f_key              => 0;
use constant f_raw_value        => 1;
use constant f_serializer       => 2;
use constant f_created_at       => 3;
use constant f_early_expires_at => 4;
use constant f_expires_at       => 5;
use constant f_is_transformed   => 6;
use constant f_cache_version    => 7;
use constant f_value            => 8;
use constant f_packed_data      => 9;
use constant f_size             => 10;

use constant T_SERIALIZED   => 1;
use constant T_UTF8_ENCODED => 2;
use constant T_COMPRESSED   => 4;

my $Metadata_Format = "LLLCC";
my $Metadata_Length = 14;

# Eschewing Moose and hash-based objects for this class to get the extra speed.
# Eventually will probably write in C anyway.

sub key              { $_[0]->[f_key] }
sub created_at       { $_[0]->[f_created_at] }
sub early_expires_at { $_[0]->[f_early_expires_at] }
sub expires_at       { $_[0]->[f_expires_at] }
sub serializer       { $_[0]->[f_serializer] }
sub _is_transformed  { $_[0]->[f_is_transformed] }
sub size             { $_[0]->[f_size] }

sub set_early_expires_at {
    $_[0]->[f_early_expires_at] = $_[1];
    undef $_[0]->[f_packed_data];
}

sub set_expires_at {
    $_[0]->[f_expires_at] = $_[1];
    undef $_[0]->[f_packed_data];
}

## no critic (ProhibitManyArgs)
sub new {
    my ( $class, $key, $value, $created_at, $early_expires_at, $expires_at,
        $serializer, $compress_threshold )
      = @_;

    # Serialize/encode value if necessary - does this belong here, or in
    # Driver.pm?
    #
    my $is_transformed = 0;
    my $raw_value      = $value;
    my $size;
    if ($serializer) {
        if ( ref($raw_value) ) {
            $raw_value = $serializer->serialize($raw_value);
            $is_transformed |= T_SERIALIZED;
        }
        elsif ( Encode::is_utf8($raw_value) ) {
            $raw_value = Encode::encode( utf8 => $raw_value );
            $is_transformed |= T_UTF8_ENCODED;
        }
        if ( defined($compress_threshold)
            && length($raw_value) > $compress_threshold )
        {
            require Compress::Zlib;
            $raw_value = Compress::Zlib::memGzip($raw_value);
            $is_transformed |= T_COMPRESSED;
        }
        $size = length($raw_value) + $Metadata_Length;
    }
    else {
        $size = 1;
    }

    # Not sure where this should be set and checked
    #
    my $cache_version = 1;

    return bless [
        $key,              $raw_value,  $serializer,     $created_at,
        $early_expires_at, $expires_at, $is_transformed, $cache_version,
        $value,            undef,       $size
    ], $class;
}

sub unpack_from_data {
    my ( $class, $key, $data, $serializer ) = @_;

    return $data if !$serializer;
    my $metadata  = substr( $data, 0, $Metadata_Length );
    my $raw_value = substr( $data, $Metadata_Length );
    my $obj       = bless [
        $key, $raw_value,
        $serializer, unpack( $Metadata_Format, $metadata )
      ],
      $class;
    $obj->[f_packed_data] = $data;
    $obj->[f_size]        = length($data);
    return $obj;
}

sub pack_to_data {
    my ($self) = @_;

    return $self if !$self->serializer;
    if ( !defined( $self->[f_packed_data] ) ) {
        my $data = pack( $Metadata_Format,
            ( @{$self} )[ f_created_at .. f_cache_version ] )
          . $self->[f_raw_value];
        $self->[f_packed_data] = $data;
    }
    return $self->[f_packed_data];
}

sub is_expired {
    my ($self) = @_;

    my $expires_at = $self->[f_expires_at];
    return undef if $expires_at == CHI_Max_Time;

    my $time = $CHI::Driver::Test_Time || time();
    my $early_expires_at = $self->[f_early_expires_at];

    return $time >= $early_expires_at
      && (
        $time >= $expires_at
        || (
            rand() < (
                ( $time - $early_expires_at ) /
                  ( $expires_at - $early_expires_at )
            )
        )
      );
}

sub value {
    my ($self) = @_;

    if ( !defined $self->[f_value] ) {
        my $value          = $self->[f_raw_value];
        my $is_transformed = $self->[f_is_transformed];
        if ( $is_transformed & T_COMPRESSED ) {
            require Compress::Zlib;
            $value = Compress::Zlib::memGunzip($value);
        }
        if ( $is_transformed & T_SERIALIZED ) {
            $value = $self->serializer->deserialize($value);
        }
        elsif ( $is_transformed & T_UTF8_ENCODED ) {
            $value = Encode::decode( utf8 => $value );
        }
        $self->[f_value] = $value;
    }
    return $self->[f_value];
}

# get_* aliases for backward compatibility with Cache::Cache
#
*get_created_at = \&created_at;
*get_expires_at = \&expires_at;

1;

__END__