tiny.sys.font.fixture

1const std = @import("std");23const Dir = std.Io.Dir;45/// Sets the `depth_max` value the tree is laid out for, at two, so a test walks6/// the fixture tree at this depth to get the counts the layout promises. A walk7/// at this bound reaches `nested/deep` and reads it, and stops short of8/// `nested/deep/deeper`.9pub const visible_depth: u8 = 2;1011/// Records what went into one tree, handed back by the call that made it. A12/// test compares the walk's results against it, because the counts depend on13/// the host that built the tree.14pub const Layout = struct {15    /// Counts how many font files a walk bounded at `visible_depth` accepts16    /// from the tree, which a test compares against the catalog's entry count.17    fonts: u32,18    /// Holds those files' sizes added together, which a test compares against19    /// the summed sizes of the admitted entries.20    bytes: u64,21    /// Reports whether the directory created with mode zero could still be22    /// opened, as it can for a privileged test process. A test reads this to23    /// know whether the directory was unreadable on this host, and the font24    /// count and the byte total follow this flag because a privileged process25    /// also admits the font inside that directory.26    locked_readable: bool,27};2829const locked_mode: Dir.Permissions = @fromBackingInt(@intCast(0o000));30const open_mode: Dir.Permissions = @fromBackingInt(@intCast(0o755));3132/// Lays the tree out inside `dir` and reports what went in, which a test calls33/// once to get a tree that exercises every case the walk has to survive. Inside34/// the tree are two levels of subdirectory, one directory below the depth35/// bound, a symbolic link pointing back at its own parent, a symbolic link to a36/// font file, a `.txt` file, a font named with an uppercase extension, and a37/// directory created with mode zero.38pub fn create(io: std.Io, dir: Dir) !Layout {39    try write(io, dir, "Regular.ttf", 64);40    try write(io, dir, "Italic.OTF", 32);41    try write(io, dir, "Notes.txt", 8);42    try dir.symLink(io, "Regular.ttf", "link.ttf", .{});43    try dir.createDir(io, "nested", open_mode);44    try write(io, dir, "nested/Bold.otf", 16);45    try dir.createDir(io, "nested/deep", open_mode);46    try write(io, dir, "nested/deep/Deep.ttc", 24);47    try dir.createDir(io, "nested/deep/deeper", open_mode);48    try write(io, dir, "nested/deep/deeper/TooDeep.ttf", 128);49    try dir.createDir(io, "loop", open_mode);50    try write(io, dir, "loop/Loop.pfb", 48);51    try dir.symLink(io, "../loop", "loop/back", .{ .is_directory = true });52    try dir.createDir(io, "locked", open_mode);53    try write(io, dir, "locked/Hidden.ttf", 12);54    try dir.setFilePermissions(io, "locked", locked_mode, .{});55    const readable = probe(io, dir);56    const layout: Layout = .{57        .fonts = if (readable) 7 else 6,58        .bytes = if (readable) 260 else 248,59        .locked_readable = readable,60    };61    std.debug.assert(layout.fonts >= 6);62    std.debug.assert(layout.bytes >= 248);63    return layout;64}6566/// Puts mode 0o755 back on the locked directory, so a test can delete its67/// temporary tree afterwards. A failure to restore it is ignored, because the68/// caller is already tearing the tree down.69pub fn release(io: std.Io, dir: Dir) void {70    dir.setFilePermissions(io, "locked", open_mode, .{}) catch {};71}7273fn probe(io: std.Io, dir: Dir) bool {74    var opened = dir.openDir(io, "locked", .{ .iterate = true }) catch return false;75    opened.close(io);76    return true;77}7879fn write(io: std.Io, dir: Dir, sub_path: []const u8, bytes: usize) !void {80    var content: [128]u8 = @splat('f');81    std.debug.assert(sub_path.len != 0);82    std.debug.assert(bytes != 0);83    std.debug.assert(bytes <= content.len);84    try dir.writeFile(io, .{ .sub_path = sub_path, .data = content[0..bytes] });85}8687/// Creates `directories` subdirectories holding `files` font files apiece, at88/// the width a real machine's font directory was measured at, so a benchmark89/// can walk a tree the size of a real host font directory. The call returns the90/// count of files created, the product of the two arguments.91pub fn createCorpus(io: std.Io, dir: Dir, directories: u16, files: u16) !u32 {92    std.debug.assert(directories != 0);93    std.debug.assert(files != 0);94    var directory_name: [32]u8 = undefined;95    var leaf_name: [64]u8 = undefined;96    var created: u32 = 0;97    for (0..directories) |directory| {98        const sub = try std.fmt.bufPrint(&directory_name, "d{d}", .{directory});99        try dir.createDir(io, sub, open_mode);100        for (0..files) |file| {101            const leaf = try std.fmt.bufPrint(&leaf_name, "{s}/f{d}.ttf", .{ sub, file });102            try dir.writeFile(io, .{ .sub_path = leaf, .data = "font" });103            created += 1;104        }105    }106    std.debug.assert(created == @as(u32, directories) * @as(u32, files));107    return created;108}

1pub const fixture = @import("fixture.zig");