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This commit is contained in:
Jakub Konka 2020-05-05 17:05:30 +02:00
parent 558bb24601
commit 07a968b344
2 changed files with 66 additions and 15 deletions
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46
lib/std/fs.zig
View File

@ -592,19 +592,27 @@ pub const Dir = struct {
return self.openFileZ(&path_c, flags);
}
fn openFileWasi(self: Dir, sub_path: []const u8, flags: File.OpenFlags) File.OpenError!File {
var fdflags: wasi.fdflag_t = 0x0;
var rights: wasi.rights_t = 0x0;
/// Save as `openFile` but WASI only.
pub fn openFileWasi(self: Dir, sub_path: []const u8, flags: File.OpenFlags) File.OpenError!File {
const w = os.wasi;
var fdflags: w.fdflag_t = 0x0;
var rights: w.rights_t = 0x0;
if (flags.read) {
rights |= wasi.FD_READ | wasi.FD_TELL | wasi.FD_FILESTAT_GET;
rights |= w.FD_READ | w.FD_TELL | w.FD_FILESTAT_GET;
}
if (flags.write) {
fdflags |= wasi.FDFLAG_APPEND;
rights |= wasi.FD_WRITE | wasi.FD_DATASYNC | wasi.FD_SEEK | wasi.FD_FDSTAT_SET_FLAGS | wasi.FD_SYNC | wasi.FD_ALLOCATE | wasi.FD_ADVISE | wasi.FD_FILESTAT_SET_TIMES | wasi.FD_FILESTAT_SET_SIZE;
fdflags |= w.FDFLAG_APPEND;
rights |= w.FD_WRITE |
w.FD_DATASYNC |
w.FD_SEEK |
w.FD_FDSTAT_SET_FLAGS |
w.FD_SYNC |
w.FD_ALLOCATE |
w.FD_ADVISE |
w.FD_FILESTAT_SET_TIMES |
w.FD_FILESTAT_SET_SIZE;
}
const fd = try wasi.openat(self.fd, sub_path, 0x0, fdflags, rights);
return File{ .handle = fd };
}
@ -700,17 +708,27 @@ pub const Dir = struct {
pub const createFileC = @compileError("deprecated: renamed to createFileZ");
fn createFileWasi(self: Dir, sub_path: []const u8, flags: File.CreateFlags) File.OpenError!File {
var oflags: wasi.oflags_t = wasi.O_CREAT;
var rights: wasi.rights_t = wasi.RIGHT_FD_WRITE | wasi.RIGHT_FD_DATASYNC | wasi.RIGHT_FD_SEEK | wasi.RIGHT_FD_FDSTAT_SET_FLAGS | wasi.RIGHT_FD_SYNC | wasi.RIGHT_FD_ALLOCATE | wasi.RIGHT_FD_ADVISE | wasi.RIGHT_FD_FILESTAT_SET_TIMES | wasi.RIGHT_FD_FILESTAT_SET_SIZE;
/// Same as `createFile` but WASI only.
pub fn createFileWasi(self: Dir, sub_path: []const u8, flags: File.CreateFlags) File.OpenError!File {
const w = os.wasi;
var oflags = w.O_CREAT;
var rights = w.RIGHT_FD_WRITE |
w.RIGHT_FD_DATASYNC |
w.RIGHT_FD_SEEK |
w.RIGHT_FD_FDSTAT_SET_FLAGS |
w.RIGHT_FD_SYNC |
w.RIGHT_FD_ALLOCATE |
w.RIGHT_FD_ADVISE |
w.RIGHT_FD_FILESTAT_SET_TIMES |
w.RIGHT_FD_FILESTAT_SET_SIZE;
if (flags.read) {
rights |= wasi.RIGHT_FD_READ | wasi.RIGHT_FD_TELL | wasi.RIGHT_FD_FILESTAT_GET;
rights |= w.RIGHT_FD_READ | w.RIGHT_FD_TELL | w.RIGHT_FD_FILESTAT_GET;
}
if (flags.truncate) {
oflags |= wasi.O_TRUNC;
oflags |= w.O_TRUNC;
}
if (flags.exclusive) {
oflags |= wasi.O_EXCL;
oflags |= w.O_EXCL;
}
const fd = try wasi.openat(self.fd, sub_path, oflags, 0x0, rights);
return File{ .handle = fd };

35
lib/std/fs/wasi.zig
View File

@ -5,18 +5,30 @@ const Allocator = mem.Allocator;
usingnamespace std.os.wasi;
/// Type of WASI preopen.
///
/// WASI currently offers only `Dir` as a valid preopen resource.
pub const PreopenType = enum {
Dir,
};
/// WASI preopen struct. This struct consists of a WASI file descriptor
/// and type of WASI preopen. It can be obtained directly from the WASI
/// runtime using `PreopenList.populate()` method.
pub const Preopen = struct {
/// WASI file descriptor.
fd: fd_t,
/// Type of the preopen.
@"type": union(PreopenType) {
/// Path to a preopened directory.
Dir: []const u8,
},
const Self = @This();
/// Construct new `Preopen` instance of type `PreopenType.Dir` from
/// WASI file descriptor and WASI path.
pub fn newDir(fd: fd_t, path: []const u8) Self {
return Self{
.fd = fd,
@ -25,18 +37,29 @@ pub const Preopen = struct {
}
};
/// Dynamically-sized array list of WASI preopens. This struct is a
/// convenience wrapper for issuing `std.os.wasi.fd_prestat_get` and
/// `std.os.wasi.fd_prestat_dir_name` syscalls to the WASI runtime, and
/// collecting the returned preopens.
///
/// This struct is intended to be used in any WASI program which intends
/// to use the capabilities as passed on by the user of the runtime.
pub const PreopenList = struct {
const InnerList = std.ArrayList(Preopen);
/// Internal dynamically-sized buffer for storing the gathered preopens.
buffer: InnerList,
const Self = @This();
pub const Error = os.UnexpectedError || Allocator.Error;
/// Deinitialize with `deinit`.
pub fn init(allocator: *Allocator) Self {
return Self{ .buffer = InnerList.init(allocator) };
}
/// Release all allocated memory.
pub fn deinit(pm: Self) void {
for (pm.buffer.items) |preopen| {
switch (preopen.@"type") {
@ -46,6 +69,8 @@ pub const PreopenList = struct {
pm.buffer.deinit();
}
/// Populate the list with the preopens by issuing `std.os.wasi.fd_prestat_get`
/// and `std.os.wasi.fd_prestat_dir_name` syscalls to the runtime.
pub fn populate(self: *Self) Error!void {
errdefer self.deinit();
var fd: fd_t = 3; // start fd has to be beyond stdio fds
@ -77,6 +102,12 @@ pub const PreopenList = struct {
}
}
/// Find preopen by path. If the preopen exists, return it.
/// Otherwise, return `null`.
///
/// TODO make the function more generic by searching by `PreopenType` union. This will
/// be needed in the future when WASI extends its capabilities to resources
/// other than preopened directories.
pub fn find(self: *const Self, path: []const u8) ?*const Preopen {
for (self.buffer.items) |preopen| {
switch (preopen.@"type") {
@ -88,12 +119,14 @@ pub const PreopenList = struct {
return null;
}
/// Return the inner buffer as read-only slice.
pub fn asSlice(self: *const Self) []const Preopen {
return self.buffer.items;
}
};
pub fn openat(dir_fd: fd_t, file_path: []const u8, oflags: oflags_t, fdflags: fdflags_t, rights: rights_t) std.os.OpenError!fd_t {
/// Convenience wrapper for `std.os.wasi.path_open` syscall.
pub fn openat(dir_fd: fd_t, file_path: []const u8, oflags: oflags_t, fdflags: fdflags_t, rights: rights_t) os.OpenError!fd_t {
var fd: fd_t = undefined;
switch (path_open(dir_fd, 0x0, file_path.ptr, file_path.len, oflags, rights, 0x0, fdflags, &fd)) {
0 => {},