view release on metacpan or  search on metacpan

t/03-frozen.t  view on Meta::CPAN

    eval { $ro->sync };
    ok !$@, 'sync on read-only view is a silent no-op';

    like exception(sub { $ro->record(1) }),        qr/read-only/, 'record on read-only view croaks';
    like exception(sub { $ro->record_many([1]) }), qr/read-only/, 'record_many on read-only view croaks';
    like exception(sub { $ro->reset }),            qr/read-only/, 'reset on read-only view croaks';
    like exception(sub { $ro->freeze }),           qr/read-only/, 'freeze on read-only view croaks';
    {
        my $other = Data::Histogram::Shared->new(undef, 1, 1_000_000, 3);
        like exception(sub { $ro->merge($other) }), qr/read-only/, 'merge on read-only view croaks';
    }
}

# ---- two independent read-only views of the same file, concurrently ----
{
    my $a = Data::Histogram::Shared->new_readonly($path);
    my $b = Data::Histogram::Shared->new_readonly($path);
    ok $a->total_count == $c && $b->total_count == $c, 'two read-only views query the same file';
}

# ---- refuse a read-write reopen of a sealed file ----
like exception(sub { Data::Histogram::Shared->new($path, 1, 1_000_000, 3) }),
     qr/frozen|read-only/, 'read-write reopen of a sealed file is refused';

# ---- new_readonly rejects a non-frozen file ----
{
    my $u = "$dir/unsealed.hist";
    { my $h = Data::Histogram::Shared->new($u, 1, 1_000_000, 3); $h->record(1); }
    like exception(sub { Data::Histogram::Shared->new_readonly($u) }),
         qr/not frozen/, 'new_readonly on an unsealed file croaks';
}

# ---- new_readonly error paths ----
like exception(sub { Data::Histogram::Shared->new_readonly("$dir/does-not-exist.hist") }),
     qr/open|No such/, 'new_readonly on a missing path croaks';
like exception(sub { Data::Histogram::Shared->new_readonly(undef) }),
     qr/required/, 'new_readonly requires a path';

# ---- merge FROM a frozen (read-only) other into a mutable histogram (lock-free o read) ----
{
    my $m   = "$dir/other.hist";
    my $B   = Data::Histogram::Shared->new($m, 1, 1_000_000, 3);
    $B->record($_) for (50, 60, 70);
    $B->freeze;
    my $Bro = Data::Histogram::Shared->new_readonly($m);

    my $A = Data::Histogram::Shared->new(undef, 1, 1_000_000, 3);   # same geometry
    $A->record(1000);
    $A->merge($Bro);   # must read Bro's counts without locking its PROT_READ map
    is $A->total_count, 4, "merge target total_count includes its own record plus the frozen other's three";
    is $A->min, 50,   'merge: min adopted from the frozen other';
    is $A->max, 1000, 'merge: max stays the local value';
    cmp_ok $A->count_at_value(1000), '>=', 1, 'merge target keeps its own item';
    cmp_ok $A->count_at_value($_), '>=', 1, "merged-in value $_ present after merge from frozen other"
        for (50, 60, 70);
}

done_testing;

# minimal exception helper (avoid a Test::Fatal dependency)
sub exception {
    my $code = shift;
    my $err;
    { local $@; eval { $code->(); 1 } or $err = $@; }
    return $err;
}