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eg/txn_test.pl  view on Meta::CPAN

#!/usr/bin/env perl
use strict;
use warnings;
use lib 'blib/lib', 'blib/arch';
use EV;
use EV::Etcd;
use Data::Dumper;

my $client = EV::Etcd->new(
    endpoints => ['127.0.0.1:2379'],
);

print "=== Transaction Test ===\n\n";

# Test 1: Compare-and-swap - create key if it doesn't exist (version == 0)
print "1. Compare-and-swap: Create '/txntest' only if it doesn't exist...\n";

$client->txn(
    # Compare: version == 0 means key doesn't exist
    [
        { key => '/txntest', target => 'version', result => '=', version => 0 },
    ],
    # Success: create the key
    [
        { put => { key => '/txntest', value => 'initial-value' } },
    ],
    # Failure: get current value
    [
        { range => { key => '/txntest' } },
    ],
    sub {
        my ($resp, $err) = @_;

        if ($err) {
            print "Transaction error: $err->{message}\n";
            EV::break;
            return;
        }

        print "   Transaction succeeded: $resp->{succeeded}\n";
        print "   Revision: $resp->{header}{revision}\n";

        if ($resp->{succeeded}) {
            print "   Key was created (didn't exist before)\n\n";
        } else {
            print "   Key already existed, got current value:\n";
            my $range_resp = $resp->{responses}[0]{response_range};
            if ($range_resp && @{$range_resp->{kvs}}) {
                print "   Value: $range_resp->{kvs}[0]{value}\n\n";
            }
        }

        # Test 2: Update only if value matches
        test_conditional_update();
    }
);

sub test_conditional_update {
    print "2. Conditional update: Change value only if current value matches...\n";

    $client->txn(
        # Compare: value must be 'initial-value'
        [
            { key => '/txntest', target => 'value', result => '=', value => 'initial-value' },
        ],
        # Success: update the value
        [
            { put => { key => '/txntest', value => 'updated-value' } },
        ],
        # Failure: do nothing (empty array)