1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
const std = @import("std");
const c = @cImport({
@cInclude("time.h");
});
pub const FileSwapper = struct {
allocator: std.mem.Allocator,
target_path: []const u8,
tmp_path: []const u8,
tmp: std.fs.File,
pub fn createAt(alloc: std.mem.Allocator, path: []const u8) !FileSwapper {
const target_dir = std.fs.path.dirname(path) orelse ".";
const target_name = std.fs.path.basename(path);
const tmp_name = try std.fmt.allocPrint(
alloc,
".{s}",
.{target_name},
);
defer alloc.free(tmp_name);
const tmp_path = try std.fs.path.join(
alloc,
&.{ target_dir, tmp_name },
);
const f = try std.fs.cwd().createFile(tmp_path, .{});
return .{
.allocator = alloc,
.target_path = path,
.tmp_path = tmp_path,
.tmp = f,
};
}
pub fn writer(self: FileSwapper) std.fs.File.Writer {
return self.tmp.writer();
}
pub fn close(self: FileSwapper) void {
defer self.allocator.free(self.tmp_path);
defer self.tmp.close();
// flush writes
self.tmp.sync() catch
@panic("sync tmp file");
// check if target path exists
var found = true;
std.fs.cwd().access(self.target_path, .{}) catch |e| switch (e) {
error.FileNotFound => found = false,
else => @panic("unable to stat target path"),
};
// swap file into final location
std.fs.rename(
std.fs.cwd(),
self.tmp_path,
std.fs.cwd(),
self.target_path,
) catch
@panic("rename tmp file");
}
};
pub fn replaceExtension(alloc: std.mem.Allocator, p: []const u8, new: []const u8) ![]const u8 {
const dirname = std.fs.path.dirname(p) orelse ".";
const basename = try stripExtension(std.fs.path.basename(p));
return try joinPathAndFilename(
alloc,
&.{dirname},
&.{ basename, ".", new },
);
}
// also trims off base paths
pub fn stripExtension(path: []const u8) ![]const u8 {
const ext = std.fs.path.extension(path);
const ext_idx = std.mem.indexOfPosLinear(u8, path, 0, ext);
std.debug.assert(ext_idx != null);
return path[0..ext_idx.?];
}
pub fn joinPathAndFilename(alloc: std.mem.Allocator, paths: []const []const u8, filename_parts: []const []const u8) ![]const u8 {
const filename = try std.mem.concat(alloc, u8, filename_parts);
defer alloc.free(filename);
var p = try std.ArrayList([]const u8).initCapacity(alloc, paths.len + 1);
defer p.deinit();
p.appendSliceAssumeCapacity(paths);
p.appendAssumeCapacity(filename);
const paths2 = try p.toOwnedSlice();
defer alloc.free(paths2);
std.debug.assert(paths.len + 1 == paths2.len);
return try std.fs.path.join(alloc, paths2);
}
pub fn getMtime(path: []const u8) !std.posix.timespec {
const fd = try std.fs.cwd().openFile(path, .{ .mode = .read_only });
defer fd.close();
const meta = try fd.metadata();
const mtime = meta.modified();
return .{
.sec = std.math.cast(isize, @divFloor(mtime, std.time.ns_per_s)) orelse std.math.maxInt(isize),
.nsec = std.math.cast(isize, @mod(mtime, std.time.ns_per_s)) orelse std.math.maxInt(isize),
};
}
// use libc strftime to format time string
pub fn formatMtime(alloc: std.mem.Allocator, mtime: std.posix.timespec, fmt: [*c]const u8) ![]const u8 {
const mtime_str = try alloc.alloc(u8, std.os.linux.PATH_MAX);
var tm: c.struct_tm = undefined;
_ = c.localtime_r(&mtime.sec, &tm);
const rc = c.strftime(
mtime_str.ptr,
mtime_str.len,
fmt,
&tm,
);
switch (std.posix.errno(rc)) {
.SUCCESS => {},
else => |err| return std.posix.unexpectedErrno(err),
}
return try alloc.realloc(mtime_str, rc);
}
|
