Mock out temp_file.odin stuff

core/os/os2/temp_file.odin

@@ -1,17 +1,190 @@
 package os2
 
+import "base:intrinsics"
 import "base:runtime"
 
-create_temp_file :: proc(dir, pattern: string) -> (^File, Error) {
-	return _create_temp(dir, pattern)
+@(private="file")
+MAX_ATTEMPTS :: 1<<13 // Should be enough for everyone, right?
+
+// Creates a new temperatory file in the directory `dir`.
+//
+// Opens the file for reading and writing, with 0o666 permissions, and returns the new `^File`.
+// The filename is generated by taking a pattern, and adding a randomized string to the end.
+// If the pattern includes an "*", the randm string replaces the last "*".
+// If `dir` is an empty tring, `temp_directory()` will be used.
+//
+// The caller must `close` the file once finished with.
+create_temp_file :: proc(dir, pattern: string) -> (f: ^File, err: Error) {
+	TEMP_ALLOCATOR_GUARD()
+	dir := dir if dir != "" else temp_directory(temp_allocator()) or_return
+	prefix, suffix := _prefix_and_suffix(pattern) or_return
+	prefix = temp_join_path(dir, prefix)
+
+	rand_buf: [32]byte
+	name_buf := make([]byte, len(prefix)+len(rand_buf)+len(suffix), temp_allocator())
+
+	attempts := 0
+	for {
+		name := concatenate_strings_from_buffer(name_buf[:], prefix, random_string(rand_buf[:]), suffix)
+		f, err = open(name, {.Read, .Write, .Create, .Excl}, File_Mode(0o666))
+		if err == .Exist {
+			close(f)
+			attempts += 1
+			if attempts < MAX_ATTEMPTS {
+				continue
+			}
+			return nil, err
+		}
+		return f, err
+	}
 }
 
 mkdir_temp :: make_directory_temp
-make_directory_temp :: proc(dir, pattern: string, allocator: runtime.Allocator) -> (string, Error) {
-	return _mkdir_temp(dir, pattern, allocator)
+// Creates a new temporary directory in the directory `dir`, and returns the path of the new directory.
+//
+// The directory name is generated by taking a pattern, and adding a randomized string to the end.
+// If the pattern includes an "*", the randm string replaces the last "*".
+// If `dir` is an empty tring, `temp_directory()` will be used.
+make_directory_temp :: proc(dir, pattern: string, allocator: runtime.Allocator) -> (temp_path: string, err: Error) {
+	TEMP_ALLOCATOR_GUARD()
+	dir := dir if dir != "" else temp_directory(temp_allocator()) or_return
+	prefix, suffix := _prefix_and_suffix(pattern) or_return
+	prefix = temp_join_path(dir, prefix)
+
+	rand_buf: [32]byte
+	name_buf := make([]byte, len(prefix)+len(rand_buf)+len(suffix), temp_allocator())
+
+	attempts := 0
+	for {
+		name := concatenate_strings_from_buffer(name_buf[:], prefix, random_string(rand_buf[:]), suffix)
+		err = make_directory(name, 0o700)
+		if err == nil {
+			return clone_string(name, allocator), nil
+		}
+		if err == .Exist {
+			attempts += 1
+			if attempts < MAX_ATTEMPTS {
+				continue
+			}
+			return "", err
+		}
+		if err == .Not_Exist {
+			if _, serr := stat(dir, temp_allocator()); serr == .Not_Exist {
+				return "", serr
+			}
+		}
+		return "", err
+	}
+
 }
 
 temp_dir :: temp_directory
 temp_directory :: proc(allocator: runtime.Allocator) -> (string, Error) {
 	return _temp_dir(allocator)
 }
+
+
+// Splits pattern by the last wildcard "*", if it exists, and returns the prefix and suffix
+// parts which are split by the last "*"
+@(private)
+_prefix_and_suffix :: proc(pattern: string) -> (prefix, suffix: string, err: Error) {
+	for i in 0..<len(pattern) {
+		if is_path_separator(pattern[i]) {
+			err = .Pattern_Has_Separator
+			return
+		}
+	}
+	prefix = pattern
+	for i := len(pattern)-1; i >= 0; i -= 1 {
+		if pattern[i] == '*' {
+			prefix, suffix = pattern[:i], pattern[i+1:]
+			break
+		}
+	}
+	return
+}
+
+@(private)
+clone_string :: proc(s: string, allocator: runtime.Allocator) -> string {
+	buf := make([]byte, len(s), allocator)
+	copy(buf, s)
+	return string(buf)
+}
+
+
+@(private)
+concatenate_strings_from_buffer :: proc(buf: []byte, strings: ..string) -> string {
+	n := 0
+	for s in strings {
+		(n < len(buf)) or_break
+		n += copy(buf[n:], s)
+	}
+	n = min(len(buf), n)
+	return string(buf[:n])
+}
+
+
+
+@(private)
+temp_join_path :: proc(dir, name: string) -> string {
+	concat :: proc(strings: ..string) -> string {
+		n := 0
+		for s in strings {
+			n += len(s)
+		}
+		buf := make([]byte, n)
+		n = 0
+		for s in strings {
+			n += copy(buf[n:], s)
+		}
+		return string(buf)
+	}
+
+	if len(dir) > 0 && is_path_separator(dir[len(dir)-1]) {
+		return concat(dir, name)
+	}
+
+	return concat(dir, Path_Separator_String, name)
+}
+
+
+@(private="file")
+random_string_seed: [2]u64
+
+@(init, private="file")
+init_random_string_seed :: proc() {
+	seed := u64(intrinsics.read_cycle_counter())
+	s := &random_string_seed
+	s[0] = 0
+	s[1] = (seed << 1) | 1
+	_ = next_random(s)
+	s[1] += seed
+	_ = next_random(s)
+}
+
+@(private="file")
+next_random :: proc(r: ^[2]u64) -> u64 {
+	old_state := r[0]
+	r[0] = old_state * 6364136223846793005 + (r[1]|1)
+	xor_shifted := (((old_state >> 59) + 5) ~ old_state) * 12605985483714917081
+	rot := (old_state >> 59)
+	return (xor_shifted >> rot) | (xor_shifted << ((-rot) & 63))
+}
+
+@(private="file")
+random_string :: proc(buf: []byte) -> string {
+	@static digits := "0123456789"
+
+	u := next_random(&random_string_seed)
+
+	b :: 10
+	i := len(buf)
+	for u >= b {
+		i -= 1
+		buf[i] = digits[u % b]
+		u /= b
+	}
+	i -= 1
+	buf[i] = digits[u % b]
+	return string(buf[i:])
+}