zig/std/io.zig

665 lines
23 KiB
Zig

const std = @import("index.zig");
const builtin = @import("builtin");
const Os = builtin.Os;
const system = switch(builtin.os) {
Os.linux => @import("os/linux.zig"),
Os.darwin, Os.macosx, Os.ios => @import("os/darwin.zig"),
Os.windows => @import("os/windows/index.zig"),
else => @compileError("Unsupported OS"),
};
const c = std.c;
const math = std.math;
const debug = std.debug;
const assert = debug.assert;
const os = std.os;
const mem = std.mem;
const Buffer = std.Buffer;
const fmt = std.fmt;
const is_posix = builtin.os != builtin.Os.windows;
const is_windows = builtin.os == builtin.Os.windows;
test "import io tests" {
comptime {
_ = @import("io_test.zig");
}
}
/// The function received invalid input at runtime. An Invalid error means a
/// bug in the program that called the function.
error Invalid;
error DiskQuota;
error FileTooBig;
error Io;
error NoSpaceLeft;
error BadPerm;
error BrokenPipe;
error BadFd;
error IsDir;
error NotDir;
error SymLinkLoop;
error ProcessFdQuotaExceeded;
error SystemFdQuotaExceeded;
error NameTooLong;
error NoDevice;
error PathNotFound;
error OutOfMemory;
error Unseekable;
error EndOfFile;
pub fn getStdErr() -> %File {
const handle = if (is_windows) {
%return os.windowsGetStdHandle(system.STD_ERROR_HANDLE)
} else if (is_posix) {
system.STDERR_FILENO
} else {
unreachable
};
return File.openHandle(handle);
}
pub fn getStdOut() -> %File {
const handle = if (is_windows) {
%return os.windowsGetStdHandle(system.STD_OUTPUT_HANDLE)
} else if (is_posix) {
system.STDOUT_FILENO
} else {
unreachable
};
return File.openHandle(handle);
}
pub fn getStdIn() -> %File {
const handle = if (is_windows) {
%return os.windowsGetStdHandle(system.STD_INPUT_HANDLE)
} else if (is_posix) {
system.STDIN_FILENO
} else {
unreachable
};
return File.openHandle(handle);
}
/// Implementation of InStream trait for File
pub const FileInStream = struct {
file: &File,
stream: InStream,
pub fn init(file: &File) -> FileInStream {
return FileInStream {
.file = file,
.stream = InStream {
.readFn = readFn,
},
};
}
fn readFn(in_stream: &InStream, buffer: []u8) -> %usize {
const self = @fieldParentPtr(FileInStream, "stream", in_stream);
return self.file.read(buffer);
}
};
/// Implementation of OutStream trait for File
pub const FileOutStream = struct {
file: &File,
stream: OutStream,
pub fn init(file: &File) -> FileOutStream {
return FileOutStream {
.file = file,
.stream = OutStream {
.writeFn = writeFn,
},
};
}
fn writeFn(out_stream: &OutStream, bytes: []const u8) -> %void {
const self = @fieldParentPtr(FileOutStream, "stream", out_stream);
return self.file.write(bytes);
}
};
pub const File = struct {
/// The OS-specific file descriptor or file handle.
handle: os.FileHandle,
/// `path` may need to be copied in memory to add a null terminating byte. In this case
/// a fixed size buffer of size std.os.max_noalloc_path_len is an attempted solution. If the fixed
/// size buffer is too small, and the provided allocator is null, error.NameTooLong is returned.
/// otherwise if the fixed size buffer is too small, allocator is used to obtain the needed memory.
/// Call close to clean up.
pub fn openRead(path: []const u8, allocator: ?&mem.Allocator) -> %File {
if (is_posix) {
const flags = system.O_LARGEFILE|system.O_RDONLY;
const fd = %return os.posixOpen(path, flags, 0, allocator);
return openHandle(fd);
} else if (is_windows) {
const handle = %return os.windowsOpen(path, system.GENERIC_READ, system.FILE_SHARE_READ,
system.OPEN_EXISTING, system.FILE_ATTRIBUTE_NORMAL, allocator);
return openHandle(handle);
} else {
unreachable;
}
}
/// Calls `openWriteMode` with 0o666 for the mode.
pub fn openWrite(path: []const u8, allocator: ?&mem.Allocator) -> %File {
return openWriteMode(path, 0o666, allocator);
}
/// `path` may need to be copied in memory to add a null terminating byte. In this case
/// a fixed size buffer of size std.os.max_noalloc_path_len is an attempted solution. If the fixed
/// size buffer is too small, and the provided allocator is null, error.NameTooLong is returned.
/// otherwise if the fixed size buffer is too small, allocator is used to obtain the needed memory.
/// Call close to clean up.
pub fn openWriteMode(path: []const u8, mode: usize, allocator: ?&mem.Allocator) -> %File {
if (is_posix) {
const flags = system.O_LARGEFILE|system.O_WRONLY|system.O_CREAT|system.O_CLOEXEC|system.O_TRUNC;
const fd = %return os.posixOpen(path, flags, mode, allocator);
return openHandle(fd);
} else if (is_windows) {
const handle = %return os.windowsOpen(path, system.GENERIC_WRITE,
system.FILE_SHARE_WRITE|system.FILE_SHARE_READ|system.FILE_SHARE_DELETE,
system.CREATE_ALWAYS, system.FILE_ATTRIBUTE_NORMAL, allocator);
return openHandle(handle);
} else {
unreachable;
}
}
pub fn openHandle(handle: os.FileHandle) -> File {
return File {
.handle = handle,
};
}
/// Upon success, the stream is in an uninitialized state. To continue using it,
/// you must use the open() function.
pub fn close(self: &File) {
os.close(self.handle);
self.handle = undefined;
}
/// Calls `os.isTty` on `self.handle`.
pub fn isTty(self: &File) -> bool {
return os.isTty(self.handle);
}
pub fn seekForward(self: &File, amount: isize) -> %void {
switch (builtin.os) {
Os.linux, Os.darwin => {
const result = system.lseek(self.handle, amount, system.SEEK_CUR);
const err = system.getErrno(result);
if (err > 0) {
return switch (err) {
system.EBADF => error.BadFd,
system.EINVAL => error.Unseekable,
system.EOVERFLOW => error.Unseekable,
system.ESPIPE => error.Unseekable,
system.ENXIO => error.Unseekable,
else => os.unexpectedErrorPosix(err),
};
}
},
else => @compileError("unsupported OS"),
}
}
pub fn seekTo(self: &File, pos: usize) -> %void {
switch (builtin.os) {
Os.linux, Os.darwin => {
const result = system.lseek(self.handle, @bitCast(isize, pos), system.SEEK_SET);
const err = system.getErrno(result);
if (err > 0) {
return switch (err) {
system.EBADF => error.BadFd,
system.EINVAL => error.Unseekable,
system.EOVERFLOW => error.Unseekable,
system.ESPIPE => error.Unseekable,
system.ENXIO => error.Unseekable,
else => os.unexpectedErrorPosix(err),
};
}
},
else => @compileError("unsupported OS"),
}
}
pub fn getPos(self: &File) -> %usize {
switch (builtin.os) {
Os.linux, Os.darwin => {
const result = system.lseek(self.handle, 0, system.SEEK_CUR);
const err = system.getErrno(result);
if (err > 0) {
return switch (err) {
system.EBADF => error.BadFd,
system.EINVAL => error.Unseekable,
system.EOVERFLOW => error.Unseekable,
system.ESPIPE => error.Unseekable,
system.ENXIO => error.Unseekable,
else => os.unexpectedErrorPosix(err),
};
}
return result;
},
else => @compileError("unsupported OS"),
}
}
pub fn getEndPos(self: &File) -> %usize {
if (is_posix) {
var stat: system.Stat = undefined;
const err = system.getErrno(system.fstat(self.handle, &stat));
if (err > 0) {
return switch (err) {
system.EBADF => error.BadFd,
system.ENOMEM => error.SystemResources,
else => os.unexpectedErrorPosix(err),
}
}
return usize(stat.size);
} else if (is_windows) {
var file_size: system.LARGE_INTEGER = undefined;
if (system.GetFileSizeEx(self.handle, &file_size) == 0) {
const err = system.GetLastError();
return switch (err) {
else => os.unexpectedErrorWindows(err),
};
}
if (file_size < 0)
return error.Overflow;
return math.cast(usize, u64(file_size));
} else {
unreachable;
}
}
pub fn read(self: &File, buffer: []u8) -> %usize {
if (is_posix) {
var index: usize = 0;
while (index < buffer.len) {
const amt_read = system.read(self.handle, &buffer[index], buffer.len - index);
const read_err = system.getErrno(amt_read);
if (read_err > 0) {
switch (read_err) {
system.EINTR => continue,
system.EINVAL => unreachable,
system.EFAULT => unreachable,
system.EBADF => return error.BadFd,
system.EIO => return error.Io,
else => return os.unexpectedErrorPosix(read_err),
}
}
if (amt_read == 0) return index;
index += amt_read;
}
return index;
} else if (is_windows) {
var index: usize = 0;
while (index < buffer.len) {
const want_read_count = system.DWORD(math.min(system.DWORD(@maxValue(system.DWORD)), buffer.len - index));
var amt_read: system.DWORD = undefined;
if (system.ReadFile(self.handle, @ptrCast(&c_void, &buffer[index]), want_read_count, &amt_read, null) == 0) {
const err = system.GetLastError();
return switch (err) {
system.ERROR.OPERATION_ABORTED => continue,
system.ERROR.BROKEN_PIPE => return index,
else => os.unexpectedErrorWindows(err),
};
}
if (amt_read == 0) return index;
index += amt_read;
}
return index;
} else {
unreachable;
}
}
fn write(self: &File, bytes: []const u8) -> %void {
if (is_posix) {
%return os.posixWrite(self.handle, bytes);
} else if (is_windows) {
%return os.windowsWrite(self.handle, bytes);
} else {
@compileError("Unsupported OS");
}
}
};
error StreamTooLong;
error EndOfStream;
pub const InStream = struct {
/// Return the number of bytes read. If the number read is smaller than buf.len, it
/// means the stream reached the end. Reaching the end of a stream is not an error
/// condition.
readFn: fn(self: &InStream, buffer: []u8) -> %usize,
/// Replaces `buffer` contents by reading from the stream until it is finished.
/// If `buffer.len()` would exceed `max_size`, `error.StreamTooLong` is returned and
/// the contents read from the stream are lost.
pub fn readAllBuffer(self: &InStream, buffer: &Buffer, max_size: usize) -> %void {
%return buffer.resize(0);
var actual_buf_len: usize = 0;
while (true) {
const dest_slice = buffer.toSlice()[actual_buf_len..];
const bytes_read = %return self.readFn(self, dest_slice);
actual_buf_len += bytes_read;
if (bytes_read != dest_slice.len) {
buffer.shrink(actual_buf_len);
return;
}
const new_buf_size = math.min(max_size, actual_buf_len + os.page_size);
if (new_buf_size == actual_buf_len)
return error.StreamTooLong;
%return buffer.resize(new_buf_size);
}
}
/// Allocates enough memory to hold all the contents of the stream. If the allocated
/// memory would be greater than `max_size`, returns `error.StreamTooLong`.
/// Caller owns returned memory.
/// If this function returns an error, the contents from the stream read so far are lost.
pub fn readAllAlloc(self: &InStream, allocator: &mem.Allocator, max_size: usize) -> %[]u8 {
var buf = Buffer.initNull(allocator);
defer buf.deinit();
%return self.readAllBuffer(&buf, max_size);
return buf.toOwnedSlice();
}
/// Replaces `buffer` contents by reading from the stream until `delimiter` is found.
/// Does not include the delimiter in the result.
/// If `buffer.len()` would exceed `max_size`, `error.StreamTooLong` is returned and the contents
/// read from the stream so far are lost.
pub fn readUntilDelimiterBuffer(self: &InStream, buffer: &Buffer, delimiter: u8, max_size: usize) -> %void {
%return buf.resize(0);
while (true) {
var byte: u8 = %return self.readByte();
if (byte == delimiter) {
return;
}
if (buf.len() == max_size) {
return error.StreamTooLong;
}
%return buf.appendByte(byte);
}
}
/// Allocates enough memory to read until `delimiter`. If the allocated
/// memory would be greater than `max_size`, returns `error.StreamTooLong`.
/// Caller owns returned memory.
/// If this function returns an error, the contents from the stream read so far are lost.
pub fn readUntilDelimiterAlloc(self: &InStream, allocator: &mem.Allocator,
delimiter: u8, max_size: usize) -> %[]u8
{
var buf = Buffer.initNull(allocator);
defer buf.deinit();
%return self.readUntilDelimiterBuffer(self, &buf, delimiter, max_size);
return buf.toOwnedSlice();
}
/// Returns the number of bytes read. If the number read is smaller than buf.len, it
/// means the stream reached the end. Reaching the end of a stream is not an error
/// condition.
pub fn read(self: &InStream, buffer: []u8) -> %usize {
return self.readFn(self, buffer);
}
/// Same as `read` but end of stream returns `error.EndOfStream`.
pub fn readNoEof(self: &InStream, buf: []u8) -> %void {
const amt_read = %return self.read(buf);
if (amt_read < buf.len) return error.EndOfStream;
}
/// Reads 1 byte from the stream or returns `error.EndOfStream`.
pub fn readByte(self: &InStream) -> %u8 {
var result: [1]u8 = undefined;
%return self.readNoEof(result[0..]);
return result[0];
}
/// Same as `readByte` except the returned byte is signed.
pub fn readByteSigned(self: &InStream) -> %i8 {
return @bitCast(i8, %return self.readByte());
}
pub fn readIntLe(self: &InStream, comptime T: type) -> %T {
return self.readInt(builtin.Endian.Little, T);
}
pub fn readIntBe(self: &InStream, comptime T: type) -> %T {
return self.readInt(builtin.Endian.Big, T);
}
pub fn readInt(self: &InStream, endian: builtin.Endian, comptime T: type) -> %T {
var bytes: [@sizeOf(T)]u8 = undefined;
%return self.readNoEof(bytes[0..]);
return mem.readInt(bytes, T, endian);
}
pub fn readVarInt(self: &InStream, endian: builtin.Endian, comptime T: type, size: usize) -> %T {
assert(size <= @sizeOf(T));
assert(size <= 8);
var input_buf: [8]u8 = undefined;
const input_slice = input_buf[0..size];
%return self.readNoEof(input_slice);
return mem.readInt(input_slice, T, endian);
}
};
pub const OutStream = struct {
writeFn: fn(self: &OutStream, bytes: []const u8) -> %void,
pub fn print(self: &OutStream, comptime format: []const u8, args: ...) -> %void {
return std.fmt.format(self, self.writeFn, format, args);
}
pub fn write(self: &OutStream, bytes: []const u8) -> %void {
return self.writeFn(self, bytes);
}
pub fn writeByte(self: &OutStream, byte: u8) -> %void {
const slice = (&byte)[0..1];
return self.writeFn(self, slice);
}
pub fn writeByteNTimes(self: &OutStream, byte: u8, n: usize) -> %void {
const slice = (&byte)[0..1];
var i: usize = 0;
while (i < n) : (i += 1) {
%return self.writeFn(self, slice);
}
}
};
/// `path` may need to be copied in memory to add a null terminating byte. In this case
/// a fixed size buffer of size `std.os.max_noalloc_path_len` is an attempted solution. If the fixed
/// size buffer is too small, and the provided allocator is null, `error.NameTooLong` is returned.
/// otherwise if the fixed size buffer is too small, allocator is used to obtain the needed memory.
pub fn writeFile(path: []const u8, data: []const u8, allocator: ?&mem.Allocator) -> %void {
var file = %return File.openWrite(path, allocator);
defer file.close();
%return file.write(data);
}
/// On success, caller owns returned buffer.
pub fn readFileAlloc(path: []const u8, allocator: &mem.Allocator) -> %[]u8 {
var file = %return File.openRead(path, allocator);
defer file.close();
const size = %return file.getEndPos();
const buf = %return allocator.alloc(u8, size);
%defer allocator.free(buf);
var adapter = FileInStream.init(&file);
%return adapter.stream.readNoEof(buf);
return buf;
}
pub const BufferedInStream = BufferedInStreamCustom(os.page_size);
pub fn BufferedInStreamCustom(comptime buffer_size: usize) -> type {
return struct {
const Self = this;
pub stream: InStream,
unbuffered_in_stream: &InStream,
buffer: [buffer_size]u8,
start_index: usize,
end_index: usize,
pub fn init(unbuffered_in_stream: &InStream) -> Self {
return Self {
.unbuffered_in_stream = unbuffered_in_stream,
.buffer = undefined,
// Initialize these two fields to buffer_size so that
// in `readFn` we treat the state as being able to read
// more from the unbuffered stream. If we set them to 0
// and 0, the code would think we already hit EOF.
.start_index = buffer_size,
.end_index = buffer_size,
.stream = InStream {
.readFn = readFn,
},
};
}
fn readFn(in_stream: &InStream, dest: []u8) -> %usize {
const self = @fieldParentPtr(Self, "stream", in_stream);
var dest_index: usize = 0;
while (true) {
const dest_space = dest.len - dest_index;
if (dest_space == 0) {
return dest_index;
}
const amt_buffered = self.end_index - self.start_index;
if (amt_buffered == 0) {
assert(self.end_index <= buffer_size);
if (self.end_index == buffer_size) {
// we can read more data from the unbuffered stream
if (dest_space < buffer_size) {
self.start_index = 0;
self.end_index = %return self.unbuffered_in_stream.read(self.buffer[0..]);
} else {
// asking for so much data that buffering is actually less efficient.
// forward the request directly to the unbuffered stream
const amt_read = %return self.unbuffered_in_stream.read(dest[dest_index..]);
return dest_index + amt_read;
}
} else {
// reading from the unbuffered stream returned less than we asked for
// so we cannot read any more data.
return dest_index;
}
}
const copy_amount = math.min(dest_space, amt_buffered);
const copy_end_index = self.start_index + copy_amount;
mem.copy(u8, dest[dest_index..], self.buffer[self.start_index..copy_end_index]);
self.start_index = copy_end_index;
dest_index += copy_amount;
}
}
};
}
pub const BufferedOutStream = BufferedOutStreamCustom(os.page_size);
pub fn BufferedOutStreamCustom(comptime buffer_size: usize) -> type {
return struct {
const Self = this;
pub stream: OutStream,
unbuffered_out_stream: &OutStream,
buffer: [buffer_size]u8,
index: usize,
pub fn init(unbuffered_out_stream: &OutStream) -> Self {
return Self {
.unbuffered_out_stream = unbuffered_out_stream,
.buffer = undefined,
.index = 0,
.stream = OutStream {
.writeFn = writeFn,
},
};
}
pub fn flush(self: &Self) -> %void {
if (self.index == 0)
return;
%return self.unbuffered_out_stream.write(self.buffer[0..self.index]);
self.index = 0;
}
fn writeFn(out_stream: &OutStream, bytes: []const u8) -> %void {
const self = @fieldParentPtr(Self, "stream", out_stream);
if (bytes.len >= self.buffer.len) {
%return self.flush();
return self.unbuffered_out_stream.write(bytes);
}
var src_index: usize = 0;
while (src_index < bytes.len) {
const dest_space_left = self.buffer.len - self.index;
const copy_amt = math.min(dest_space_left, bytes.len - src_index);
mem.copy(u8, self.buffer[self.index..], bytes[src_index..src_index + copy_amt]);
self.index += copy_amt;
assert(self.index <= self.buffer.len);
if (self.index == self.buffer.len) {
%return self.flush();
}
src_index += copy_amt;
}
}
};
}
/// Implementation of OutStream trait for Buffer
pub const BufferOutStream = struct {
buffer: &Buffer,
stream: OutStream,
pub fn init(buffer: &Buffer) -> BufferOutStream {
return BufferOutStream {
.buffer = buffer,
.stream = OutStream {
.writeFn = writeFn,
},
};
}
fn writeFn(out_stream: &OutStream, bytes: []const u8) -> %void {
const self = @fieldParentPtr(BufferOutStream, "stream", out_stream);
return self.buffer.append(bytes);
}
};