motiejus/zig
1
Fork 0
Code Releases Activity

std.os.windows.GetFinalPathNameByHandle: remove QueryInformationFile code path

Browse Source
This commit is contained in:
Rohlem
2020-12-23 21:50:08 +01:00
committed by Andrew Kelley
parent cb20503990
commit f301a8467c
1 changed files with 22 additions and 56 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
lib/std/os/windows.zig
View File

@@ -28,10 +28,6 @@ pub const gdi32 = @import("windows/gdi32.zig");
pub usingnamespace @import("windows/bits.zig");
//version detection
const version = std.zig.system.windows;
const WindowsVersion = version.WindowsVersion;
pub const self_process_handle = @intToPtr(HANDLE, maxInt(usize));
pub const OpenError = error{
@@ -1034,65 +1030,35 @@ pub fn GetFinalPathNameByHandle(
out_buffer: []u16,
) GetFinalPathNameByHandleError![]u16 {
var path_buffer: [math.max(@sizeOf(FILE_NAME_INFORMATION), @sizeOf(OBJECT_NAME_INFORMATION)) + PATH_MAX_WIDE * 2]u8 align(@alignOf(FILE_NAME_INFORMATION)) = undefined;
var volume_buffer: [@sizeOf(FILE_NAME_INFORMATION) + MAX_PATH]u8 align(@alignOf(FILE_NAME_INFORMATION)) = undefined; // MAX_PATH bytes should be enough since it's Windows-defined name
const final_path = QueryObjectName(hFile, mem.bytesAsSlice(u16, &path_buffer)) catch |err| switch (err) {
// we assume InvalidHandle is close enough to FileNotFound in semantics
// to not further complicate the error set
error.InvalidHandle => return error.FileNotFound,
else => |e| return e,
};
var file_name_u16: []const u16 = undefined;
var volume_name_u16: []const u16 = undefined;
if ((comptime (std.builtin.os.version_range.windows.isAtLeast(WindowsVersion.win10_rs4) != true)) and !version.detectRuntimeVersion().isAtLeast(WindowsVersion.win10_rs4)) {
const final_path = QueryObjectName(hFile, mem.bytesAsSlice(u16, &path_buffer)) catch |err| return switch (err) {
// we assume InvalidHandle is close enough to FileNotFound in semantics
// to not further complicate the error set
error.InvalidHandle => error.FileNotFound,
else => |e| e,
};
if (fmt.volume_name == .Nt) {
switch (fmt.volume_name) {
.Nt => {
// the returned path is already in .Nt format
if (out_buffer.len < final_path.len) {
return error.NameTooLong;
}
mem.copy(u16, out_buffer, final_path);
return out_buffer[0..final_path.len];
}
//otherwise we need to parse the string for volume path for the .Dos logic below to work
const expected_prefix = std.unicode.utf8ToUtf16LeStringLiteral("\\Device\\");
// TODO find out if a path can start with something besides `\Device\<volume name>`,
// and if we need to handle it differently
// (i.e. how to determine the start and end of the volume name in that case)
if (!mem.eql(u16, expected_prefix, final_path[0..expected_prefix.len])) return error.Unexpected;
const index = mem.indexOfPos(u16, final_path, expected_prefix.len, &[_]u16{'\\'}) orelse unreachable;
volume_name_u16 = final_path[0..index];
file_name_u16 = final_path[index..];
//fallthrough for fmt.volume_name != .Nt
} else {
// Get normalized path; doesn't include volume name though.
try QueryInformationFile(hFile, .FileNormalizedNameInformation, &path_buffer);
const file_name = @ptrCast(*const FILE_NAME_INFORMATION, &path_buffer);
file_name_u16 = @ptrCast([*]const u16, &file_name.FileName)[0..@divExact(file_name.FileNameLength, 2)];
// Get NT volume name.
try QueryInformationFile(hFile, .FileVolumeNameInformation, &volume_buffer);
const volume_name_info = @ptrCast(*const FILE_NAME_INFORMATION, &volume_buffer);
volume_name_u16 = @ptrCast([*]const u16, &volume_name_info.FileName)[0..@divExact(volume_name_info.FileNameLength, 2)];
if (fmt.volume_name == .Nt) {
// Nothing to do, we simply copy the bytes to the user-provided buffer.
if (out_buffer.len < volume_name_u16.len + file_name_u16.len) return error.NameTooLong;
mem.copy(u16, out_buffer, volume_name_u16);
mem.copy(u16, out_buffer[volume_name_u16.len..], file_name_u16);
return out_buffer[0 .. volume_name_u16.len + file_name_u16.len];
}
//fallthrough for fmt.volume_name != .Nt
}
switch (fmt.volume_name) {
.Nt => unreachable, //handled above
},
.Dos => {
// parse the string to separate volume path from file path
const expected_prefix = std.unicode.utf8ToUtf16LeStringLiteral("\\Device\\");
// TODO find out if a path can start with something besides `\Device\<volume name>`,
// and if we need to handle it differently
// (i.e. how to determine the start and end of the volume name in that case)
if (!mem.eql(u16, expected_prefix, final_path[0..expected_prefix.len])) return error.Unexpected;
const file_path_begin_index = mem.indexOfPos(u16, final_path, expected_prefix.len, &[_]u16{'\\'}) orelse unreachable;
const volume_name_u16 = final_path[0..file_path_begin_index];
const file_name_u16 = final_path[file_path_begin_index..];
// Get DOS volume name. DOS volume names are actually symbolic link objects to the
// actual NT volume. For example:
// (NT) \Device\HarddiskVolume4 => (DOS) \DosDevices\C: == (DOS) C: