mirror of
https://github.com/ziglang/zig.git
synced 2025-12-06 06:13:07 +00:00
d29871977f
We already have a LICENSE file that covers the Zig Standard Library. We no longer need to remind everyone that the license is MIT in every single file. Previously this was introduced to clarify the situation for a fork of Zig that made Zig's LICENSE file harder to find, and replaced it with their own license that required annual payments to their company. However that fork now appears to be dead. So there is no need to reinforce the copyright notice in every single file.
1008 lines
40 KiB
Zig
1008 lines
40 KiB
Zig
const std = @import("../std.zig");
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const builtin = std.builtin;
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const os = std.os;
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const io = std.io;
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const mem = std.mem;
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const math = std.math;
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const assert = std.debug.assert;
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const windows = os.windows;
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const Os = builtin.Os;
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const maxInt = std.math.maxInt;
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const is_windows = std.Target.current.os.tag == .windows;
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pub const File = struct {
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/// The OS-specific file descriptor or file handle.
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handle: os.fd_t,
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/// On some systems, such as Linux, file system file descriptors are incapable of non-blocking I/O.
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/// This forces us to perform asynchronous I/O on a dedicated thread, to achieve non-blocking
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/// file-system I/O. To do this, `File` must be aware of whether it is a file system file descriptor,
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/// or, more specifically, whether the I/O is always blocking.
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capable_io_mode: io.ModeOverride = io.default_mode,
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/// Furthermore, even when `std.io.mode` is async, it is still sometimes desirable to perform blocking I/O,
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/// although not by default. For example, when printing a stack trace to stderr.
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/// This field tracks both by acting as an overriding I/O mode. When not building in async I/O mode,
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/// the type only has the `.blocking` tag, making it a zero-bit type.
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intended_io_mode: io.ModeOverride = io.default_mode,
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pub const Mode = os.mode_t;
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pub const INode = os.ino_t;
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pub const Kind = enum {
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BlockDevice,
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CharacterDevice,
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Directory,
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NamedPipe,
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SymLink,
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File,
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UnixDomainSocket,
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Whiteout,
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Unknown,
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};
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pub const default_mode = switch (builtin.os.tag) {
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.windows => 0,
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.wasi => 0,
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else => 0o666,
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};
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pub const OpenError = error{
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SharingViolation,
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PathAlreadyExists,
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FileNotFound,
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AccessDenied,
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PipeBusy,
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NameTooLong,
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/// On Windows, file paths must be valid Unicode.
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InvalidUtf8,
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/// On Windows, file paths cannot contain these characters:
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/// '/', '*', '?', '"', '<', '>', '|'
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BadPathName,
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Unexpected,
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} || os.OpenError || os.FlockError;
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pub const Lock = enum { None, Shared, Exclusive };
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/// TODO https://github.com/ziglang/zig/issues/3802
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pub const OpenFlags = struct {
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read: bool = true,
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write: bool = false,
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/// Open the file with an advisory lock to coordinate with other processes
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/// accessing it at the same time. An exclusive lock will prevent other
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/// processes from acquiring a lock. A shared lock will prevent other
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/// processes from acquiring a exclusive lock, but does not prevent
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/// other process from getting their own shared locks.
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///
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/// The lock is advisory, except on Linux in very specific cirsumstances[1].
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/// This means that a process that does not respect the locking API can still get access
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/// to the file, despite the lock.
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///
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/// On these operating systems, the lock is acquired atomically with
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/// opening the file:
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/// * Darwin
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/// * DragonFlyBSD
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/// * FreeBSD
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/// * Haiku
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/// * NetBSD
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/// * OpenBSD
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/// On these operating systems, the lock is acquired via a separate syscall
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/// after opening the file:
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/// * Linux
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/// * Windows
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///
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/// [1]: https://www.kernel.org/doc/Documentation/filesystems/mandatory-locking.txt
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lock: Lock = .None,
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/// Sets whether or not to wait until the file is locked to return. If set to true,
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/// `error.WouldBlock` will be returned. Otherwise, the file will wait until the file
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/// is available to proceed.
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/// In async I/O mode, non-blocking at the OS level is
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/// determined by `intended_io_mode`, and `true` means `error.WouldBlock` is returned,
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/// and `false` means `error.WouldBlock` is handled by the event loop.
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lock_nonblocking: bool = false,
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/// Setting this to `.blocking` prevents `O_NONBLOCK` from being passed even
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/// if `std.io.is_async`. It allows the use of `nosuspend` when calling functions
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/// related to opening the file, reading, writing, and locking.
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intended_io_mode: io.ModeOverride = io.default_mode,
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/// Set this to allow the opened file to automatically become the
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/// controlling TTY for the current process.
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allow_ctty: bool = false,
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};
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/// TODO https://github.com/ziglang/zig/issues/3802
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pub const CreateFlags = struct {
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/// Whether the file will be created with read access.
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read: bool = false,
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/// If the file already exists, and is a regular file, and the access
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/// mode allows writing, it will be truncated to length 0.
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truncate: bool = true,
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/// Ensures that this open call creates the file, otherwise causes
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/// `error.PathAlreadyExists` to be returned.
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exclusive: bool = false,
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/// Open the file with an advisory lock to coordinate with other processes
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/// accessing it at the same time. An exclusive lock will prevent other
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/// processes from acquiring a lock. A shared lock will prevent other
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/// processes from acquiring a exclusive lock, but does not prevent
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/// other process from getting their own shared locks.
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///
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/// The lock is advisory, except on Linux in very specific cirsumstances[1].
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/// This means that a process that does not respect the locking API can still get access
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/// to the file, despite the lock.
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///
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/// On these operating systems, the lock is acquired atomically with
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/// opening the file:
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/// * Darwin
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/// * DragonFlyBSD
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/// * FreeBSD
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/// * Haiku
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/// * NetBSD
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/// * OpenBSD
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/// On these operating systems, the lock is acquired via a separate syscall
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/// after opening the file:
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/// * Linux
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/// * Windows
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///
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/// [1]: https://www.kernel.org/doc/Documentation/filesystems/mandatory-locking.txt
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lock: Lock = .None,
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/// Sets whether or not to wait until the file is locked to return. If set to true,
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/// `error.WouldBlock` will be returned. Otherwise, the file will wait until the file
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/// is available to proceed.
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/// In async I/O mode, non-blocking at the OS level is
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/// determined by `intended_io_mode`, and `true` means `error.WouldBlock` is returned,
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/// and `false` means `error.WouldBlock` is handled by the event loop.
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lock_nonblocking: bool = false,
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/// For POSIX systems this is the file system mode the file will
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/// be created with.
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mode: Mode = default_mode,
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/// Setting this to `.blocking` prevents `O_NONBLOCK` from being passed even
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/// if `std.io.is_async`. It allows the use of `nosuspend` when calling functions
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/// related to opening the file, reading, writing, and locking.
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intended_io_mode: io.ModeOverride = io.default_mode,
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};
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/// Upon success, the stream is in an uninitialized state. To continue using it,
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/// you must use the open() function.
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pub fn close(self: File) void {
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if (is_windows) {
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windows.CloseHandle(self.handle);
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} else if (self.capable_io_mode != self.intended_io_mode) {
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std.event.Loop.instance.?.close(self.handle);
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} else {
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os.close(self.handle);
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}
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}
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/// Test whether the file refers to a terminal.
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/// See also `supportsAnsiEscapeCodes`.
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pub fn isTty(self: File) bool {
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return os.isatty(self.handle);
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}
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/// Test whether ANSI escape codes will be treated as such.
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pub fn supportsAnsiEscapeCodes(self: File) bool {
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if (builtin.os.tag == .windows) {
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return os.isCygwinPty(self.handle);
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}
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if (builtin.os.tag == .wasi) {
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// WASI sanitizes stdout when fd is a tty so ANSI escape codes
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// will not be interpreted as actual cursor commands, and
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// stderr is always sanitized.
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return false;
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}
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if (self.isTty()) {
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if (self.handle == os.STDOUT_FILENO or self.handle == os.STDERR_FILENO) {
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// Use getenvC to workaround https://github.com/ziglang/zig/issues/3511
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if (os.getenvZ("TERM")) |term| {
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if (std.mem.eql(u8, term, "dumb"))
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return false;
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}
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}
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return true;
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}
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return false;
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}
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pub const SetEndPosError = os.TruncateError;
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/// Shrinks or expands the file.
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/// The file offset after this call is left unchanged.
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pub fn setEndPos(self: File, length: u64) SetEndPosError!void {
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try os.ftruncate(self.handle, length);
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}
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pub const SeekError = os.SeekError;
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/// Repositions read/write file offset relative to the current offset.
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/// TODO: integrate with async I/O
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pub fn seekBy(self: File, offset: i64) SeekError!void {
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return os.lseek_CUR(self.handle, offset);
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}
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/// Repositions read/write file offset relative to the end.
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/// TODO: integrate with async I/O
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pub fn seekFromEnd(self: File, offset: i64) SeekError!void {
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return os.lseek_END(self.handle, offset);
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}
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/// Repositions read/write file offset relative to the beginning.
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/// TODO: integrate with async I/O
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pub fn seekTo(self: File, offset: u64) SeekError!void {
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return os.lseek_SET(self.handle, offset);
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}
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pub const GetSeekPosError = os.SeekError || os.FStatError;
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/// TODO: integrate with async I/O
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pub fn getPos(self: File) GetSeekPosError!u64 {
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return os.lseek_CUR_get(self.handle);
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}
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/// TODO: integrate with async I/O
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pub fn getEndPos(self: File) GetSeekPosError!u64 {
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if (builtin.os.tag == .windows) {
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return windows.GetFileSizeEx(self.handle);
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}
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return (try self.stat()).size;
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}
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pub const ModeError = os.FStatError;
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/// TODO: integrate with async I/O
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pub fn mode(self: File) ModeError!Mode {
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if (builtin.os.tag == .windows) {
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return 0;
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}
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return (try self.stat()).mode;
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}
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pub const Stat = struct {
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/// A number that the system uses to point to the file metadata. This number is not guaranteed to be
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/// unique across time, as some file systems may reuse an inode after its file has been deleted.
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/// Some systems may change the inode of a file over time.
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///
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/// On Linux, the inode is a structure that stores the metadata, and the inode _number_ is what
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/// you see here: the index number of the inode.
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///
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/// The FileIndex on Windows is similar. It is a number for a file that is unique to each filesystem.
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inode: INode,
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size: u64,
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mode: Mode,
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kind: Kind,
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/// Access time in nanoseconds, relative to UTC 1970-01-01.
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atime: i128,
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/// Last modification time in nanoseconds, relative to UTC 1970-01-01.
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mtime: i128,
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/// Creation time in nanoseconds, relative to UTC 1970-01-01.
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ctime: i128,
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};
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pub const StatError = os.FStatError;
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/// TODO: integrate with async I/O
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pub fn stat(self: File) StatError!Stat {
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if (builtin.os.tag == .windows) {
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var io_status_block: windows.IO_STATUS_BLOCK = undefined;
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var info: windows.FILE_ALL_INFORMATION = undefined;
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const rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &info, @sizeOf(windows.FILE_ALL_INFORMATION), .FileAllInformation);
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switch (rc) {
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.SUCCESS => {},
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.BUFFER_OVERFLOW => {},
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.INVALID_PARAMETER => unreachable,
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.ACCESS_DENIED => return error.AccessDenied,
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else => return windows.unexpectedStatus(rc),
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}
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return Stat{
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.inode = info.InternalInformation.IndexNumber,
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.size = @bitCast(u64, info.StandardInformation.EndOfFile),
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.mode = 0,
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.kind = if (info.StandardInformation.Directory == 0) .File else .Directory,
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.atime = windows.fromSysTime(info.BasicInformation.LastAccessTime),
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.mtime = windows.fromSysTime(info.BasicInformation.LastWriteTime),
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.ctime = windows.fromSysTime(info.BasicInformation.CreationTime),
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};
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}
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const st = try os.fstat(self.handle);
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const atime = st.atime();
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const mtime = st.mtime();
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const ctime = st.ctime();
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return Stat{
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.inode = st.ino,
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.size = @bitCast(u64, st.size),
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.mode = st.mode,
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.kind = if (builtin.os.tag == .wasi and !builtin.link_libc) switch (st.filetype) {
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os.FILETYPE_BLOCK_DEVICE => Kind.BlockDevice,
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os.FILETYPE_CHARACTER_DEVICE => Kind.CharacterDevice,
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os.FILETYPE_DIRECTORY => Kind.Directory,
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os.FILETYPE_SYMBOLIC_LINK => Kind.SymLink,
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os.FILETYPE_REGULAR_FILE => Kind.File,
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os.FILETYPE_SOCKET_STREAM, os.FILETYPE_SOCKET_DGRAM => Kind.UnixDomainSocket,
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else => Kind.Unknown,
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} else switch (st.mode & os.S_IFMT) {
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os.S_IFBLK => Kind.BlockDevice,
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os.S_IFCHR => Kind.CharacterDevice,
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os.S_IFDIR => Kind.Directory,
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os.S_IFIFO => Kind.NamedPipe,
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os.S_IFLNK => Kind.SymLink,
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os.S_IFREG => Kind.File,
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os.S_IFSOCK => Kind.UnixDomainSocket,
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else => Kind.Unknown,
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},
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.atime = @as(i128, atime.tv_sec) * std.time.ns_per_s + atime.tv_nsec,
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.mtime = @as(i128, mtime.tv_sec) * std.time.ns_per_s + mtime.tv_nsec,
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.ctime = @as(i128, ctime.tv_sec) * std.time.ns_per_s + ctime.tv_nsec,
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};
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}
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pub const UpdateTimesError = os.FutimensError || windows.SetFileTimeError;
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/// The underlying file system may have a different granularity than nanoseconds,
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/// and therefore this function cannot guarantee any precision will be stored.
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/// Further, the maximum value is limited by the system ABI. When a value is provided
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/// that exceeds this range, the value is clamped to the maximum.
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/// TODO: integrate with async I/O
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pub fn updateTimes(
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self: File,
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/// access timestamp in nanoseconds
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atime: i128,
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/// last modification timestamp in nanoseconds
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mtime: i128,
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) UpdateTimesError!void {
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if (builtin.os.tag == .windows) {
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const atime_ft = windows.nanoSecondsToFileTime(atime);
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const mtime_ft = windows.nanoSecondsToFileTime(mtime);
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return windows.SetFileTime(self.handle, null, &atime_ft, &mtime_ft);
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}
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const times = [2]os.timespec{
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os.timespec{
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.tv_sec = math.cast(isize, @divFloor(atime, std.time.ns_per_s)) catch maxInt(isize),
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.tv_nsec = math.cast(isize, @mod(atime, std.time.ns_per_s)) catch maxInt(isize),
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},
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os.timespec{
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.tv_sec = math.cast(isize, @divFloor(mtime, std.time.ns_per_s)) catch maxInt(isize),
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.tv_nsec = math.cast(isize, @mod(mtime, std.time.ns_per_s)) catch maxInt(isize),
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},
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};
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try os.futimens(self.handle, ×);
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}
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/// Reads all the bytes from the current position to the end of the file.
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/// On success, caller owns returned buffer.
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/// If the file is larger than `max_bytes`, returns `error.FileTooBig`.
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pub fn readToEndAlloc(self: File, allocator: *mem.Allocator, max_bytes: usize) ![]u8 {
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return self.readToEndAllocOptions(allocator, max_bytes, null, @alignOf(u8), null);
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}
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/// Reads all the bytes from the current position to the end of the file.
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/// On success, caller owns returned buffer.
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/// If the file is larger than `max_bytes`, returns `error.FileTooBig`.
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/// If `size_hint` is specified the initial buffer size is calculated using
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/// that value, otherwise an arbitrary value is used instead.
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/// Allows specifying alignment and a sentinel value.
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pub fn readToEndAllocOptions(
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self: File,
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allocator: *mem.Allocator,
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max_bytes: usize,
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size_hint: ?usize,
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comptime alignment: u29,
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comptime optional_sentinel: ?u8,
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) !(if (optional_sentinel) |s| [:s]align(alignment) u8 else []align(alignment) u8) {
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// If no size hint is provided fall back to the size=0 code path
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const size = size_hint orelse 0;
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// The file size returned by stat is used as hint to set the buffer
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// size. If the reported size is zero, as it happens on Linux for files
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// in /proc, a small buffer is allocated instead.
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const initial_cap = (if (size > 0) size else 1024) + @boolToInt(optional_sentinel != null);
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var array_list = try std.ArrayListAligned(u8, alignment).initCapacity(allocator, initial_cap);
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defer array_list.deinit();
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self.reader().readAllArrayListAligned(alignment, &array_list, max_bytes) catch |err| switch (err) {
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error.StreamTooLong => return error.FileTooBig,
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else => |e| return e,
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};
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if (optional_sentinel) |sentinel| {
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try array_list.append(sentinel);
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const buf = array_list.toOwnedSlice();
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return buf[0 .. buf.len - 1 :sentinel];
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} else {
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return array_list.toOwnedSlice();
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}
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}
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pub const ReadError = os.ReadError;
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pub const PReadError = os.PReadError;
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pub fn read(self: File, buffer: []u8) ReadError!usize {
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if (is_windows) {
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return windows.ReadFile(self.handle, buffer, null, self.intended_io_mode);
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}
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if (self.intended_io_mode == .blocking) {
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return os.read(self.handle, buffer);
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} else {
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return std.event.Loop.instance.?.read(self.handle, buffer, self.capable_io_mode != self.intended_io_mode);
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}
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}
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/// Returns the number of bytes read. If the number read is smaller than `buffer.len`, it
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/// means the file reached the end. Reaching the end of a file is not an error condition.
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pub fn readAll(self: File, buffer: []u8) ReadError!usize {
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var index: usize = 0;
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while (index != buffer.len) {
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const amt = try self.read(buffer[index..]);
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if (amt == 0) break;
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index += amt;
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}
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return index;
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}
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pub fn pread(self: File, buffer: []u8, offset: u64) PReadError!usize {
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if (is_windows) {
|
|
return windows.ReadFile(self.handle, buffer, offset, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.pread(self.handle, buffer, offset);
|
|
} else {
|
|
return std.event.Loop.instance.?.pread(self.handle, buffer, offset, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
/// Returns the number of bytes read. If the number read is smaller than `buffer.len`, it
|
|
/// means the file reached the end. Reaching the end of a file is not an error condition.
|
|
pub fn preadAll(self: File, buffer: []u8, offset: u64) PReadError!usize {
|
|
var index: usize = 0;
|
|
while (index != buffer.len) {
|
|
const amt = try self.pread(buffer[index..], offset + index);
|
|
if (amt == 0) break;
|
|
index += amt;
|
|
}
|
|
return index;
|
|
}
|
|
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
pub fn readv(self: File, iovecs: []const os.iovec) ReadError!usize {
|
|
if (is_windows) {
|
|
// TODO improve this to use ReadFileScatter
|
|
if (iovecs.len == 0) return @as(usize, 0);
|
|
const first = iovecs[0];
|
|
return windows.ReadFile(self.handle, first.iov_base[0..first.iov_len], null, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.readv(self.handle, iovecs);
|
|
} else {
|
|
return std.event.Loop.instance.?.readv(self.handle, iovecs, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
/// Returns the number of bytes read. If the number read is smaller than the total bytes
|
|
/// from all the buffers, it means the file reached the end. Reaching the end of a file
|
|
/// is not an error condition.
|
|
/// The `iovecs` parameter is mutable because this function needs to mutate the fields in
|
|
/// order to handle partial reads from the underlying OS layer.
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
pub fn readvAll(self: File, iovecs: []os.iovec) ReadError!usize {
|
|
if (iovecs.len == 0) return 0;
|
|
|
|
var i: usize = 0;
|
|
var off: usize = 0;
|
|
while (true) {
|
|
var amt = try self.readv(iovecs[i..]);
|
|
var eof = amt == 0;
|
|
off += amt;
|
|
while (amt >= iovecs[i].iov_len) {
|
|
amt -= iovecs[i].iov_len;
|
|
i += 1;
|
|
if (i >= iovecs.len) return off;
|
|
eof = false;
|
|
}
|
|
if (eof) return off;
|
|
iovecs[i].iov_base += amt;
|
|
iovecs[i].iov_len -= amt;
|
|
}
|
|
}
|
|
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
pub fn preadv(self: File, iovecs: []const os.iovec, offset: u64) PReadError!usize {
|
|
if (is_windows) {
|
|
// TODO improve this to use ReadFileScatter
|
|
if (iovecs.len == 0) return @as(usize, 0);
|
|
const first = iovecs[0];
|
|
return windows.ReadFile(self.handle, first.iov_base[0..first.iov_len], offset, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.preadv(self.handle, iovecs, offset);
|
|
} else {
|
|
return std.event.Loop.instance.?.preadv(self.handle, iovecs, offset, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
/// Returns the number of bytes read. If the number read is smaller than the total bytes
|
|
/// from all the buffers, it means the file reached the end. Reaching the end of a file
|
|
/// is not an error condition.
|
|
/// The `iovecs` parameter is mutable because this function needs to mutate the fields in
|
|
/// order to handle partial reads from the underlying OS layer.
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
pub fn preadvAll(self: File, iovecs: []os.iovec, offset: u64) PReadError!usize {
|
|
if (iovecs.len == 0) return 0;
|
|
|
|
var i: usize = 0;
|
|
var off: usize = 0;
|
|
while (true) {
|
|
var amt = try self.preadv(iovecs[i..], offset + off);
|
|
var eof = amt == 0;
|
|
off += amt;
|
|
while (amt >= iovecs[i].iov_len) {
|
|
amt -= iovecs[i].iov_len;
|
|
i += 1;
|
|
if (i >= iovecs.len) return off;
|
|
eof = false;
|
|
}
|
|
if (eof) return off;
|
|
iovecs[i].iov_base += amt;
|
|
iovecs[i].iov_len -= amt;
|
|
}
|
|
}
|
|
|
|
pub const WriteError = os.WriteError;
|
|
pub const PWriteError = os.PWriteError;
|
|
|
|
pub fn write(self: File, bytes: []const u8) WriteError!usize {
|
|
if (is_windows) {
|
|
return windows.WriteFile(self.handle, bytes, null, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.write(self.handle, bytes);
|
|
} else {
|
|
return std.event.Loop.instance.?.write(self.handle, bytes, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
pub fn writeAll(self: File, bytes: []const u8) WriteError!void {
|
|
var index: usize = 0;
|
|
while (index < bytes.len) {
|
|
index += try self.write(bytes[index..]);
|
|
}
|
|
}
|
|
|
|
pub fn pwrite(self: File, bytes: []const u8, offset: u64) PWriteError!usize {
|
|
if (is_windows) {
|
|
return windows.WriteFile(self.handle, bytes, offset, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.pwrite(self.handle, bytes, offset);
|
|
} else {
|
|
return std.event.Loop.instance.?.pwrite(self.handle, bytes, offset, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
pub fn pwriteAll(self: File, bytes: []const u8, offset: u64) PWriteError!void {
|
|
var index: usize = 0;
|
|
while (index < bytes.len) {
|
|
index += try self.pwrite(bytes[index..], offset + index);
|
|
}
|
|
}
|
|
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
/// See equivalent function: `std.net.Stream.writev`.
|
|
pub fn writev(self: File, iovecs: []const os.iovec_const) WriteError!usize {
|
|
if (is_windows) {
|
|
// TODO improve this to use WriteFileScatter
|
|
if (iovecs.len == 0) return @as(usize, 0);
|
|
const first = iovecs[0];
|
|
return windows.WriteFile(self.handle, first.iov_base[0..first.iov_len], null, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.writev(self.handle, iovecs);
|
|
} else {
|
|
return std.event.Loop.instance.?.writev(self.handle, iovecs, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
/// The `iovecs` parameter is mutable because this function needs to mutate the fields in
|
|
/// order to handle partial writes from the underlying OS layer.
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
/// See equivalent function: `std.net.Stream.writevAll`.
|
|
pub fn writevAll(self: File, iovecs: []os.iovec_const) WriteError!void {
|
|
if (iovecs.len == 0) return;
|
|
|
|
var i: usize = 0;
|
|
while (true) {
|
|
var amt = try self.writev(iovecs[i..]);
|
|
while (amt >= iovecs[i].iov_len) {
|
|
amt -= iovecs[i].iov_len;
|
|
i += 1;
|
|
if (i >= iovecs.len) return;
|
|
}
|
|
iovecs[i].iov_base += amt;
|
|
iovecs[i].iov_len -= amt;
|
|
}
|
|
}
|
|
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
pub fn pwritev(self: File, iovecs: []os.iovec_const, offset: u64) PWriteError!usize {
|
|
if (is_windows) {
|
|
// TODO improve this to use WriteFileScatter
|
|
if (iovecs.len == 0) return @as(usize, 0);
|
|
const first = iovecs[0];
|
|
return windows.WriteFile(self.handle, first.iov_base[0..first.iov_len], offset, self.intended_io_mode);
|
|
}
|
|
|
|
if (self.intended_io_mode == .blocking) {
|
|
return os.pwritev(self.handle, iovecs, offset);
|
|
} else {
|
|
return std.event.Loop.instance.?.pwritev(self.handle, iovecs, offset, self.capable_io_mode != self.intended_io_mode);
|
|
}
|
|
}
|
|
|
|
/// The `iovecs` parameter is mutable because this function needs to mutate the fields in
|
|
/// order to handle partial writes from the underlying OS layer.
|
|
/// See https://github.com/ziglang/zig/issues/7699
|
|
pub fn pwritevAll(self: File, iovecs: []os.iovec_const, offset: u64) PWriteError!void {
|
|
if (iovecs.len == 0) return;
|
|
|
|
var i: usize = 0;
|
|
var off: u64 = 0;
|
|
while (true) {
|
|
var amt = try self.pwritev(iovecs[i..], offset + off);
|
|
off += amt;
|
|
while (amt >= iovecs[i].iov_len) {
|
|
amt -= iovecs[i].iov_len;
|
|
i += 1;
|
|
if (i >= iovecs.len) return;
|
|
}
|
|
iovecs[i].iov_base += amt;
|
|
iovecs[i].iov_len -= amt;
|
|
}
|
|
}
|
|
|
|
pub const CopyRangeError = os.CopyFileRangeError;
|
|
|
|
pub fn copyRange(in: File, in_offset: u64, out: File, out_offset: u64, len: u64) CopyRangeError!u64 {
|
|
const adjusted_len = math.cast(usize, len) catch math.maxInt(usize);
|
|
const result = try os.copy_file_range(in.handle, in_offset, out.handle, out_offset, adjusted_len, 0);
|
|
return result;
|
|
}
|
|
|
|
/// Returns the number of bytes copied. If the number read is smaller than `buffer.len`, it
|
|
/// means the in file reached the end. Reaching the end of a file is not an error condition.
|
|
pub fn copyRangeAll(in: File, in_offset: u64, out: File, out_offset: u64, len: u64) CopyRangeError!u64 {
|
|
var total_bytes_copied: u64 = 0;
|
|
var in_off = in_offset;
|
|
var out_off = out_offset;
|
|
while (total_bytes_copied < len) {
|
|
const amt_copied = try copyRange(in, in_off, out, out_off, len - total_bytes_copied);
|
|
if (amt_copied == 0) return total_bytes_copied;
|
|
total_bytes_copied += amt_copied;
|
|
in_off += amt_copied;
|
|
out_off += amt_copied;
|
|
}
|
|
return total_bytes_copied;
|
|
}
|
|
|
|
pub const WriteFileOptions = struct {
|
|
in_offset: u64 = 0,
|
|
|
|
/// `null` means the entire file. `0` means no bytes from the file.
|
|
/// When this is `null`, trailers must be sent in a separate writev() call
|
|
/// due to a flaw in the BSD sendfile API. Other operating systems, such as
|
|
/// Linux, already do this anyway due to API limitations.
|
|
/// If the size of the source file is known, passing the size here will save one syscall.
|
|
in_len: ?u64 = null,
|
|
|
|
headers_and_trailers: []os.iovec_const = &[0]os.iovec_const{},
|
|
|
|
/// The trailer count is inferred from `headers_and_trailers.len - header_count`
|
|
header_count: usize = 0,
|
|
};
|
|
|
|
pub const WriteFileError = ReadError || error{EndOfStream} || WriteError;
|
|
|
|
pub fn writeFileAll(self: File, in_file: File, args: WriteFileOptions) WriteFileError!void {
|
|
return self.writeFileAllSendfile(in_file, args) catch |err| switch (err) {
|
|
error.Unseekable,
|
|
error.FastOpenAlreadyInProgress,
|
|
error.MessageTooBig,
|
|
error.FileDescriptorNotASocket,
|
|
error.NetworkUnreachable,
|
|
error.NetworkSubsystemFailed,
|
|
=> return self.writeFileAllUnseekable(in_file, args),
|
|
|
|
else => |e| return e,
|
|
};
|
|
}
|
|
|
|
/// Does not try seeking in either of the File parameters.
|
|
/// See `writeFileAll` as an alternative to calling this.
|
|
pub fn writeFileAllUnseekable(self: File, in_file: File, args: WriteFileOptions) WriteFileError!void {
|
|
const headers = args.headers_and_trailers[0..args.header_count];
|
|
const trailers = args.headers_and_trailers[args.header_count..];
|
|
|
|
try self.writevAll(headers);
|
|
|
|
try in_file.reader().skipBytes(args.in_offset, .{ .buf_size = 4096 });
|
|
|
|
var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init();
|
|
if (args.in_len) |len| {
|
|
var stream = std.io.limitedReader(in_file.reader(), len);
|
|
try fifo.pump(stream.reader(), self.writer());
|
|
} else {
|
|
try fifo.pump(in_file.reader(), self.writer());
|
|
}
|
|
|
|
try self.writevAll(trailers);
|
|
}
|
|
|
|
/// Low level function which can fail for OS-specific reasons.
|
|
/// See `writeFileAll` as an alternative to calling this.
|
|
/// TODO integrate with async I/O
|
|
fn writeFileAllSendfile(self: File, in_file: File, args: WriteFileOptions) os.SendFileError!void {
|
|
const count = blk: {
|
|
if (args.in_len) |l| {
|
|
if (l == 0) {
|
|
return self.writevAll(args.headers_and_trailers);
|
|
} else {
|
|
break :blk l;
|
|
}
|
|
} else {
|
|
break :blk 0;
|
|
}
|
|
};
|
|
const headers = args.headers_and_trailers[0..args.header_count];
|
|
const trailers = args.headers_and_trailers[args.header_count..];
|
|
const zero_iovec = &[0]os.iovec_const{};
|
|
// When reading the whole file, we cannot put the trailers in the sendfile() syscall,
|
|
// because we have no way to determine whether a partial write is past the end of the file or not.
|
|
const trls = if (count == 0) zero_iovec else trailers;
|
|
const offset = args.in_offset;
|
|
const out_fd = self.handle;
|
|
const in_fd = in_file.handle;
|
|
const flags = 0;
|
|
var amt: usize = 0;
|
|
hdrs: {
|
|
var i: usize = 0;
|
|
while (i < headers.len) {
|
|
amt = try os.sendfile(out_fd, in_fd, offset, count, headers[i..], trls, flags);
|
|
while (amt >= headers[i].iov_len) {
|
|
amt -= headers[i].iov_len;
|
|
i += 1;
|
|
if (i >= headers.len) break :hdrs;
|
|
}
|
|
headers[i].iov_base += amt;
|
|
headers[i].iov_len -= amt;
|
|
}
|
|
}
|
|
if (count == 0) {
|
|
var off: u64 = amt;
|
|
while (true) {
|
|
amt = try os.sendfile(out_fd, in_fd, offset + off, 0, zero_iovec, zero_iovec, flags);
|
|
if (amt == 0) break;
|
|
off += amt;
|
|
}
|
|
} else {
|
|
var off: u64 = amt;
|
|
while (off < count) {
|
|
amt = try os.sendfile(out_fd, in_fd, offset + off, count - off, zero_iovec, trailers, flags);
|
|
off += amt;
|
|
}
|
|
amt = @intCast(usize, off - count);
|
|
}
|
|
var i: usize = 0;
|
|
while (i < trailers.len) {
|
|
while (amt >= trailers[i].iov_len) {
|
|
amt -= trailers[i].iov_len;
|
|
i += 1;
|
|
if (i >= trailers.len) return;
|
|
}
|
|
trailers[i].iov_base += amt;
|
|
trailers[i].iov_len -= amt;
|
|
amt = try os.writev(self.handle, trailers[i..]);
|
|
}
|
|
}
|
|
|
|
pub const Reader = io.Reader(File, ReadError, read);
|
|
|
|
pub fn reader(file: File) Reader {
|
|
return .{ .context = file };
|
|
}
|
|
|
|
pub const Writer = io.Writer(File, WriteError, write);
|
|
|
|
pub fn writer(file: File) Writer {
|
|
return .{ .context = file };
|
|
}
|
|
|
|
pub const SeekableStream = io.SeekableStream(
|
|
File,
|
|
SeekError,
|
|
GetSeekPosError,
|
|
seekTo,
|
|
seekBy,
|
|
getPos,
|
|
getEndPos,
|
|
);
|
|
|
|
pub fn seekableStream(file: File) SeekableStream {
|
|
return .{ .context = file };
|
|
}
|
|
|
|
const range_off: windows.LARGE_INTEGER = 0;
|
|
const range_len: windows.LARGE_INTEGER = 1;
|
|
|
|
pub const LockError = error{
|
|
SystemResources,
|
|
} || os.UnexpectedError;
|
|
|
|
/// Blocks when an incompatible lock is held by another process.
|
|
/// A process may hold only one type of lock (shared or exclusive) on
|
|
/// a file. When a process terminates in any way, the lock is released.
|
|
///
|
|
/// Assumes the file is unlocked.
|
|
///
|
|
/// TODO: integrate with async I/O
|
|
pub fn lock(file: File, l: Lock) LockError!void {
|
|
if (is_windows) {
|
|
var io_status_block: windows.IO_STATUS_BLOCK = undefined;
|
|
const exclusive = switch (l) {
|
|
.None => return,
|
|
.Shared => false,
|
|
.Exclusive => true,
|
|
};
|
|
return windows.LockFile(
|
|
file.handle,
|
|
null,
|
|
null,
|
|
null,
|
|
&io_status_block,
|
|
&range_off,
|
|
&range_len,
|
|
null,
|
|
windows.FALSE, // non-blocking=false
|
|
@boolToInt(exclusive),
|
|
) catch |err| switch (err) {
|
|
error.WouldBlock => unreachable, // non-blocking=false
|
|
else => |e| return e,
|
|
};
|
|
} else {
|
|
return os.flock(file.handle, switch (l) {
|
|
.None => os.LOCK_UN,
|
|
.Shared => os.LOCK_SH,
|
|
.Exclusive => os.LOCK_EX,
|
|
}) catch |err| switch (err) {
|
|
error.WouldBlock => unreachable, // non-blocking=false
|
|
else => |e| return e,
|
|
};
|
|
}
|
|
}
|
|
|
|
/// Assumes the file is locked.
|
|
pub fn unlock(file: File) void {
|
|
if (is_windows) {
|
|
var io_status_block: windows.IO_STATUS_BLOCK = undefined;
|
|
return windows.UnlockFile(
|
|
file.handle,
|
|
&io_status_block,
|
|
&range_off,
|
|
&range_len,
|
|
null,
|
|
) catch |err| switch (err) {
|
|
error.RangeNotLocked => unreachable, // Function assumes unlocked.
|
|
error.Unexpected => unreachable, // Resource deallocation must succeed.
|
|
};
|
|
} else {
|
|
return os.flock(file.handle, os.LOCK_UN) catch |err| switch (err) {
|
|
error.WouldBlock => unreachable, // unlocking can't block
|
|
error.SystemResources => unreachable, // We are deallocating resources.
|
|
error.Unexpected => unreachable, // Resource deallocation must succeed.
|
|
};
|
|
}
|
|
}
|
|
|
|
/// Attempts to obtain a lock, returning `true` if the lock is
|
|
/// obtained, and `false` if there was an existing incompatible lock held.
|
|
/// A process may hold only one type of lock (shared or exclusive) on
|
|
/// a file. When a process terminates in any way, the lock is released.
|
|
///
|
|
/// Assumes the file is unlocked.
|
|
///
|
|
/// TODO: integrate with async I/O
|
|
pub fn tryLock(file: File, l: Lock) LockError!bool {
|
|
if (is_windows) {
|
|
var io_status_block: windows.IO_STATUS_BLOCK = undefined;
|
|
const exclusive = switch (l) {
|
|
.None => return,
|
|
.Shared => false,
|
|
.Exclusive => true,
|
|
};
|
|
windows.LockFile(
|
|
file.handle,
|
|
null,
|
|
null,
|
|
null,
|
|
&io_status_block,
|
|
&range_off,
|
|
&range_len,
|
|
null,
|
|
windows.TRUE, // non-blocking=true
|
|
@boolToInt(exclusive),
|
|
) catch |err| switch (err) {
|
|
error.WouldBlock => return false,
|
|
else => |e| return e,
|
|
};
|
|
} else {
|
|
os.flock(file.handle, switch (l) {
|
|
.None => os.LOCK_UN,
|
|
.Shared => os.LOCK_SH | os.LOCK_NB,
|
|
.Exclusive => os.LOCK_EX | os.LOCK_NB,
|
|
}) catch |err| switch (err) {
|
|
error.WouldBlock => return false,
|
|
else => |e| return e,
|
|
};
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Assumes the file is already locked in exclusive mode.
|
|
/// Atomically modifies the lock to be in shared mode, without releasing it.
|
|
///
|
|
/// TODO: integrate with async I/O
|
|
pub fn downgradeLock(file: File) LockError!void {
|
|
if (is_windows) {
|
|
// On Windows it works like a semaphore + exclusivity flag. To implement this
|
|
// function, we first obtain another lock in shared mode. This changes the
|
|
// exclusivity flag, but increments the semaphore to 2. So we follow up with
|
|
// an NtUnlockFile which decrements the semaphore but does not modify the
|
|
// exclusivity flag.
|
|
var io_status_block: windows.IO_STATUS_BLOCK = undefined;
|
|
windows.LockFile(
|
|
file.handle,
|
|
null,
|
|
null,
|
|
null,
|
|
&io_status_block,
|
|
&range_off,
|
|
&range_len,
|
|
null,
|
|
windows.TRUE, // non-blocking=true
|
|
windows.FALSE, // exclusive=false
|
|
) catch |err| switch (err) {
|
|
error.WouldBlock => unreachable, // File was not locked in exclusive mode.
|
|
else => |e| return e,
|
|
};
|
|
return windows.UnlockFile(
|
|
file.handle,
|
|
&io_status_block,
|
|
&range_off,
|
|
&range_len,
|
|
null,
|
|
) catch |err| switch (err) {
|
|
error.RangeNotLocked => unreachable, // File was not locked.
|
|
error.Unexpected => unreachable, // Resource deallocation must succeed.
|
|
};
|
|
} else {
|
|
return os.flock(file.handle, os.LOCK_SH | os.LOCK_NB) catch |err| switch (err) {
|
|
error.WouldBlock => unreachable, // File was not locked in exclusive mode.
|
|
else => |e| return e,
|
|
};
|
|
}
|
|
}
|
|
};
|