const std = @import("index.zig"); const builtin = @import("builtin"); const Os = builtin.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 File = std.os.File; const is_posix = builtin.os != builtin.Os.windows; const is_windows = builtin.os == builtin.Os.windows; const GetStdIoErrs = os.WindowsGetStdHandleErrs; pub fn getStdErr() GetStdIoErrs!File { const handle = if (is_windows) try os.windowsGetStdHandle(os.windows.STD_ERROR_HANDLE) else if (is_posix) os.posix.STDERR_FILENO else unreachable; return File.openHandle(handle); } pub fn getStdOut() GetStdIoErrs!File { const handle = if (is_windows) try os.windowsGetStdHandle(os.windows.STD_OUTPUT_HANDLE) else if (is_posix) os.posix.STDOUT_FILENO else unreachable; return File.openHandle(handle); } pub fn getStdIn() GetStdIoErrs!File { const handle = if (is_windows) try os.windowsGetStdHandle(os.windows.STD_INPUT_HANDLE) else if (is_posix) os.posix.STDIN_FILENO else unreachable; return File.openHandle(handle); } /// Implementation of InStream trait for File pub const FileInStream = struct { file: &File, stream: Stream, pub const Error = @typeOf(File.read).ReturnType.ErrorSet; pub const Stream = InStream(Error); pub fn init(file: &File) FileInStream { return FileInStream { .file = file, .stream = Stream { .readFn = readFn, }, }; } fn readFn(in_stream: &Stream, buffer: []u8) Error!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: Stream, pub const Error = File.WriteError; pub const Stream = OutStream(Error); pub fn init(file: &File) FileOutStream { return FileOutStream { .file = file, .stream = Stream { .writeFn = writeFn, }, }; } fn writeFn(out_stream: &Stream, bytes: []const u8) !void { const self = @fieldParentPtr(FileOutStream, "stream", out_stream); return self.file.write(bytes); } }; pub fn InStream(comptime ReadError: type) type { return struct { const Self = this; pub const Error = ReadError; /// 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: &Self, buffer: []u8) Error!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: &Self, buffer: &Buffer, max_size: usize) !void { try buffer.resize(0); var actual_buf_len: usize = 0; while (true) { const dest_slice = buffer.toSlice()[actual_buf_len..]; const bytes_read = try 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; try 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: &Self, allocator: &mem.Allocator, max_size: usize) ![]u8 { var buf = Buffer.initNull(allocator); defer buf.deinit(); try 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: &Self, buffer: &Buffer, delimiter: u8, max_size: usize) !void { try buf.resize(0); while (true) { var byte: u8 = try self.readByte(); if (byte == delimiter) { return; } if (buf.len() == max_size) { return error.StreamTooLong; } try 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: &Self, allocator: &mem.Allocator, delimiter: u8, max_size: usize) ![]u8 { var buf = Buffer.initNull(allocator); defer buf.deinit(); try 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: &Self, buffer: []u8) !usize { return self.readFn(self, buffer); } /// Same as `read` but end of stream returns `error.EndOfStream`. pub fn readNoEof(self: &Self, buf: []u8) !void { const amt_read = try 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: &Self) !u8 { var result: [1]u8 = undefined; try self.readNoEof(result[0..]); return result[0]; } /// Same as `readByte` except the returned byte is signed. pub fn readByteSigned(self: &Self) !i8 { return @bitCast(i8, try self.readByte()); } pub fn readIntLe(self: &Self, comptime T: type) !T { return self.readInt(builtin.Endian.Little, T); } pub fn readIntBe(self: &Self, comptime T: type) !T { return self.readInt(builtin.Endian.Big, T); } pub fn readInt(self: &Self, endian: builtin.Endian, comptime T: type) !T { var bytes: [@sizeOf(T)]u8 = undefined; try self.readNoEof(bytes[0..]); return mem.readInt(bytes, T, endian); } pub fn readVarInt(self: &Self, 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]; try self.readNoEof(input_slice); return mem.readInt(input_slice, T, endian); } }; } pub fn OutStream(comptime WriteError: type) type { return struct { const Self = this; pub const Error = WriteError; writeFn: fn(self: &Self, bytes: []const u8) Error!void, pub fn print(self: &Self, comptime format: []const u8, args: ...) !void { return std.fmt.format(self, Error, self.writeFn, format, args); } pub fn write(self: &Self, bytes: []const u8) !void { return self.writeFn(self, bytes); } pub fn writeByte(self: &Self, byte: u8) !void { const slice = (&byte)[0..1]; return self.writeFn(self, slice); } pub fn writeByteNTimes(self: &Self, byte: u8, n: usize) !void { const slice = (&byte)[0..1]; var i: usize = 0; while (i < n) : (i += 1) { try self.writeFn(self, slice); } } }; } /// `path` needs to be copied in memory to add a null terminating byte, hence the allocator. pub fn writeFile(allocator: &mem.Allocator, path: []const u8, data: []const u8) !void { var file = try File.openWrite(allocator, path); defer file.close(); try file.write(data); } /// On success, caller owns returned buffer. pub fn readFileAlloc(allocator: &mem.Allocator, path: []const u8) ![]u8 { var file = try File.openRead(allocator, path); defer file.close(); const size = try file.getEndPos(); const buf = try allocator.alloc(u8, size); errdefer allocator.free(buf); var adapter = FileInStream.init(&file); try adapter.stream.readNoEof(buf[0..size]); return buf; } pub fn BufferedInStream(comptime Error: type) type { return BufferedInStreamCustom(os.page_size, Error); } pub fn BufferedInStreamCustom(comptime buffer_size: usize, comptime Error: type) type { return struct { const Self = this; const Stream = InStream(Error); pub stream: Stream, unbuffered_in_stream: &Stream, buffer: [buffer_size]u8, start_index: usize, end_index: usize, pub fn init(unbuffered_in_stream: &Stream) 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 = Stream { .readFn = readFn, }, }; } fn readFn(in_stream: &Stream, 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 = try 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 = try 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 fn BufferedOutStream(comptime Error: type) type { return BufferedOutStreamCustom(os.page_size, Error); } pub fn BufferedOutStreamCustom(comptime buffer_size: usize, comptime OutStreamError: type) type { return struct { const Self = this; pub const Stream = OutStream(Error); pub const Error = OutStreamError; pub stream: Stream, unbuffered_out_stream: &Stream, buffer: [buffer_size]u8, index: usize, pub fn init(unbuffered_out_stream: &Stream) Self { return Self { .unbuffered_out_stream = unbuffered_out_stream, .buffer = undefined, .index = 0, .stream = Stream { .writeFn = writeFn, }, }; } pub fn flush(self: &Self) !void { try self.unbuffered_out_stream.write(self.buffer[0..self.index]); self.index = 0; } fn writeFn(out_stream: &Stream, bytes: []const u8) !void { const self = @fieldParentPtr(Self, "stream", out_stream); if (bytes.len >= self.buffer.len) { try 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) { try self.flush(); } src_index += copy_amt; } } }; } /// Implementation of OutStream trait for Buffer pub const BufferOutStream = struct { buffer: &Buffer, stream: Stream, pub const Error = error{OutOfMemory}; pub const Stream = OutStream(Error); pub fn init(buffer: &Buffer) BufferOutStream { return BufferOutStream { .buffer = buffer, .stream = Stream { .writeFn = writeFn, }, }; } fn writeFn(out_stream: &Stream, bytes: []const u8) !void { const self = @fieldParentPtr(BufferOutStream, "stream", out_stream); return self.buffer.append(bytes); } }; pub const BufferedAtomicFile = struct { atomic_file: os.AtomicFile, file_stream: FileOutStream, buffered_stream: BufferedOutStream(FileOutStream.Error), pub fn create(allocator: &mem.Allocator, dest_path: []const u8) !&BufferedAtomicFile { // TODO with well defined copy elision we don't need this allocation var self = try allocator.create(BufferedAtomicFile); errdefer allocator.destroy(self); *self = BufferedAtomicFile { .atomic_file = undefined, .file_stream = undefined, .buffered_stream = undefined, }; self.atomic_file = try os.AtomicFile.init(allocator, dest_path, os.default_file_mode); errdefer self.atomic_file.deinit(); self.file_stream = FileOutStream.init(&self.atomic_file.file); self.buffered_stream = BufferedOutStream(FileOutStream.Error).init(&self.file_stream.stream); return self; } /// always call destroy, even after successful finish() pub fn destroy(self: &BufferedAtomicFile) void { const allocator = self.atomic_file.allocator; self.atomic_file.deinit(); allocator.destroy(self); } pub fn finish(self: &BufferedAtomicFile) !void { try self.buffered_stream.flush(); try self.atomic_file.finish(); } pub fn stream(self: &BufferedAtomicFile) &OutStream(FileOutStream.Error) { return &self.buffered_stream.stream; } }; test "import io tests" { comptime { _ = @import("io_test.zig"); } }