const std = @import("std");
const main = @import("main.zig");
const model = @import("model.zig");
// Concise stat struct for fields we're interested in, with the types used by the model.
const Stat = struct {
blocks: u61,
size: u64,
dev: u64,
ino: u64,
nlink: u32,
dir: bool,
reg: bool,
symlink: bool,
ext: model.Ext,
};
// Cast any integer type to the target type, clamping the
// value to the supported maximum if necessary.
fn castClamp(comptime T: type, x: anytype) T {
// (adapted from std.math.cast)
if (std.math.maxInt(@TypeOf(x)) > std.math.maxInt(T) and x > std.math.maxInt(T)) {
return std.math.maxInt(T);
} else if (std.math.minInt(@TypeOf(x)) < std.math.minInt(T) and x < std.math.minInt(T)) {
return std.math.minInt(T);
} else {
return @intCast(T, x);
}
}
// Cast any integer type to the unsigned target type, wrapping/truncating as necessary.
fn castWrap(comptime T: type, x: anytype) T {
return @intCast(T, x); // TODO
}
fn clamp(comptime T: type, comptime field: anytype, x: anytype) std.meta.fieldInfo(T, field).field_type {
return castClamp(std.meta.fieldInfo(T, field).field_type, x);
}
fn wrap(comptime T: type, comptime field: anytype, x: anytype) std.meta.fieldInfo(T, field).field_type {
return castWrap(std.meta.fieldInfo(T, field).field_type, x);
}
fn readStat(parent: std.fs.Dir, name: [:0]const u8, follow: bool) !Stat {
const stat = try std.os.fstatatZ(parent.fd, name, if (follow) 0 else std.os.AT_SYMLINK_NOFOLLOW);
return Stat{
.blocks = clamp(Stat, .blocks, stat.blocks),
.size = clamp(Stat, .size, stat.size),
.dev = wrap(Stat, .dev, stat.dev),
.ino = wrap(Stat, .ino, stat.ino),
.nlink = clamp(Stat, .nlink, stat.nlink),
.dir = std.os.system.S_ISDIR(stat.mode),
.reg = std.os.system.S_ISREG(stat.mode),
.symlink = std.os.system.S_ISLNK(stat.mode),
.ext = .{
.mtime = clamp(model.Ext, .mtime, stat.mtime().tv_sec),
.uid = wrap(model.Ext, .uid, stat.uid),
.gid = wrap(model.Ext, .gid, stat.gid),
.mode = clamp(model.Ext, .mode, stat.mode & 0xffff),
},
};
}
// Read and index entries of the given dir. The entry for the directory is already assumed to be in 'parents'.
// (TODO: shouldn't error on OOM but instead call a function that waits or something)
fn scanDir(parents: *model.Parents, dir: std.fs.Dir) std.mem.Allocator.Error!void {
var it = dir.iterate();
while(true) {
const entry = it.next() catch {
parents.top().entry.set_err(parents);
return;
} orelse break;
// TODO: Check for exclude patterns
// XXX: Surely the name already has a trailing \0 in the buffer received by the OS?
// XXX#2: Does this allocate PATH_MAX bytes on the stack for each level of recursion!?
const name_z = std.os.toPosixPath(entry.name) catch undefined;
var stat = readStat(dir, &name_z, false) catch {
var e = try model.Entry.create(.file, false, entry.name);
e.insert(parents) catch unreachable;
e.set_err(parents);
continue;
};
if (main.config.same_fs and stat.dev != model.getDev(parents.top().dev)) {
var e = try model.Entry.create(.file, false, entry.name);
e.file().?.other_fs = true;
e.insert(parents) catch unreachable;
continue;
}
if (main.config.follow_symlinks and stat.symlink) {
if (readStat(dir, &name_z, true)) |nstat| {
if (!nstat.dir) {
stat = nstat;
// Symlink targets may reside on different filesystems,
// this will break hardlink detection and counting so let's disable it.
if (stat.nlink > 1 and stat.dev != model.getDev(parents.top().dev))
stat.nlink = 1;
}
} else |_| {}
}
// TODO: Check for kernfs; Zig has no wrappers for fstatfs() yet and calling the syscall directly doesn't seem too trivial. :(
var edir =
if (stat.dir) dir.openDirZ(&name_z, .{ .access_sub_paths = true, .iterate = true, .no_follow = true }) catch {
var e = try model.Entry.create(.file, false, entry.name);
e.insert(parents) catch unreachable;
e.set_err(parents);
continue;
} else null;
defer if (edir != null) edir.?.close();
if (main.config.exclude_caches and stat.dir) {
if (edir.?.openFileZ("CACHEDIR.TAG", .{})) |f| {
const sig = "Signature: 8a477f597d28d172789f06886806bc55";
var buf: [sig.len]u8 = undefined;
if (f.reader().readAll(&buf)) |len| {
if (len == sig.len and std.mem.eql(u8, &buf, sig)) {
var e = try model.Entry.create(.file, false, entry.name);
e.file().?.excluded = true;
e.insert(parents) catch unreachable;
continue;
}
} else |_| {}
} else |_| {}
}
const etype = if (stat.dir) model.EType.dir else if (stat.nlink > 1) model.EType.link else model.EType.file;
var e = try model.Entry.create(etype, main.config.extended, entry.name);
e.blocks = stat.blocks;
e.size = stat.size;
if (e.dir()) |d| {
d.dev = try model.getDevId(stat.dev);
// The dir entry itself also counts.
d.total_blocks = stat.blocks;
d.total_size = stat.size;
d.total_items = 1;
}
if (e.file()) |f| f.notreg = !stat.dir and !stat.reg;
if (e.link()) |l| {
l.ino = stat.ino;
l.nlink = stat.nlink;
}
if (e.ext()) |ext| ext.* = stat.ext;
try e.insert(parents);
if (e.dir()) |d| {
try parents.push(d);
try scanDir(parents, edir.?);
parents.pop();
}
}
}
pub fn scanRoot(path: []const u8) !void {
// XXX: Both realpathAlloc() and toPosixPath are limited to PATH_MAX.
// Oh well, I suppose we can accept that as limitation for the top-level dir we're scanning.
const full_path = try std.os.toPosixPath(try std.fs.realpathAlloc(main.allocator, path));
const stat = try readStat(std.fs.cwd(), &full_path, true);
if (!stat.dir) return error.NotADirectory;
model.root = (try model.Entry.create(.dir, false, &full_path)).dir().?;
model.root.entry.blocks = stat.blocks;
model.root.entry.size = stat.size;
model.root.dev = try model.getDevId(stat.dev);
if (model.root.entry.ext()) |ext| ext.* = stat.ext;
var parents = model.Parents{};
const dir = try std.fs.cwd().openDirZ(&full_path, .{ .access_sub_paths = true, .iterate = true });
try scanDir(&parents, dir);
}