OrderedUserValue

const OrderedUserValue = union(enum)

File

Code

const OrderedUserValue = union(enum) {
    flag: void,
    scalar: []const u8,
    list: std.array_list.Managed([]const u8),
    map: std.array_list.Managed(Pair),
    lazy_path: LazyPath,
    lazy_path_list: std.array_list.Managed(LazyPath),

    const Pair = struct {
        name: []const u8,
        value: OrderedUserValue,
        fn lessThan(_: void, lhs: Pair, rhs: Pair) bool {
            return std.ascii.lessThanIgnoreCase(lhs.name, rhs.name);
        }
    };

    fn hash(val: OrderedUserValue, hasher: *std.hash.Wyhash) void {
        hasher.update(&std.mem.toBytes(std.meta.activeTag(val)));
        switch (val) {
            .flag => {},
            .scalar => |scalar| hasher.update(scalar),
            // lists are already ordered
            .list => |list| for (list.items) |list_entry|
                hasher.update(list_entry),
            .map => |map| for (map.items) |map_entry| {
                hasher.update(map_entry.name);
                map_entry.value.hash(hasher);
            },
            .lazy_path => |lp| hashLazyPath(lp, hasher),
            .lazy_path_list => |lp_list| for (lp_list.items) |lp| {
                hashLazyPath(lp, hasher);
            },
        }
    }

    fn hashLazyPath(lp: LazyPath, hasher: *std.hash.Wyhash) void {
        switch (lp) {
            .src_path => |sp| {
                hasher.update(sp.owner.pkg_hash);
                hasher.update(sp.sub_path);
            },
            .generated => |gen| {
                hasher.update(@ptrCast(&gen.index));
                hasher.update(@ptrCast(&gen.up));
                hasher.update(gen.sub_path);
            },
            .cwd_relative => |rel_path| {
                hasher.update(rel_path);
            },
            .relative => |r| {
                hasher.update(@ptrCast(&r.base));
                hasher.update(@ptrCast(&r.sub_path));
            },
            .dependency => |dep| {
                hasher.update(dep.dependency.builder.pkg_hash);
                hasher.update(dep.sub_path);
            },
        }
    }

    fn mapFromUnordered(allocator: Allocator, unordered: std.StringHashMap(*const UserValue)) std.array_list.Managed(Pair) {
        var ordered = std.array_list.Managed(Pair).init(allocator);
        var it = unordered.iterator();
        while (it.next()) |entry| {
            ordered.append(.{
                .name = entry.key_ptr.*,
                .value = OrderedUserValue.fromUnordered(allocator, entry.value_ptr.*.*),
            }) catch @panic("OOM");
        }

        std.mem.sortUnstable(Pair, ordered.items, {}, Pair.lessThan);
        return ordered;
    }

    fn fromUnordered(allocator: Allocator, unordered: UserValue) OrderedUserValue {
        return switch (unordered) {
            .flag => .{ .flag = {} },
            .scalar => |scalar| .{ .scalar = scalar },
            .list => |list| .{ .list = list },
            .map => |map| .{ .map = OrderedUserValue.mapFromUnordered(allocator, map) },
            .lazy_path => |lp| .{ .lazy_path = lp },
            .lazy_path_list => |list| .{ .lazy_path_list = list },
        };
    }
}