Commit 1ab66f3b55
Changed files (4)
std/meta/index.zig
@@ -95,7 +95,7 @@ test "std.meta.stringToEnum" {
debug.assert(null == stringToEnum(E1, "C"));
}
-pub fn bitCount(comptime T: type) u32 {
+pub fn bitCount(comptime T: type) comptime_int {
return switch (@typeInfo(T)) {
TypeId.Int => |info| info.bits,
TypeId.Float => |info| info.bits,
@@ -108,7 +108,7 @@ test "std.meta.bitCount" {
debug.assert(bitCount(f32) == 32);
}
-pub fn alignment(comptime T: type) u29 {
+pub fn alignment(comptime T: type) comptime_int {
//@alignOf works on non-pointer types
const P = if (comptime trait.is(TypeId.Pointer)(T)) T else *T;
return @typeInfo(P).Pointer.alignment;
@@ -386,6 +386,33 @@ test "std.meta.activeTag" {
debug.assert(activeTag(u) == UE.Float);
}
+///Given a tagged union type, and an enum, return the type of the union
+/// field corresponding to the enum tag.
+pub fn TagPayloadType(comptime U: type, tag: var) type {
+ const Tag = @typeOf(tag);
+ debug.assert(trait.is(builtin.TypeId.Union)(U));
+ debug.assert(trait.is(builtin.TypeId.Enum)(Tag));
+
+ const info = @typeInfo(U).Union;
+
+ inline for (info.fields) |field_info| {
+ if (field_info.enum_field.?.value == @enumToInt(tag)) return field_info.field_type;
+ }
+ unreachable;
+}
+
+test "std.meta.TagPayloadType" {
+ const Event = union(enum) {
+ Moved: struct {
+ from: i32,
+ to: i32,
+ },
+ };
+ const MovedEvent = TagPayloadType(Event, Event.Moved);
+ var e: Event = undefined;
+ debug.assert(MovedEvent == @typeOf(e.Moved));
+}
+
///Compares two of any type for equality. Containers are compared on a field-by-field basis,
/// where possible. Pointers are not followed.
pub fn eql(a: var, b: @typeOf(a)) bool {
@@ -439,6 +466,11 @@ pub fn eql(a: var, b: @typeOf(a)) bool {
builtin.TypeInfo.Pointer.Size.Slice => return a.ptr == b.ptr and a.len == b.len,
}
},
+ builtin.TypeId.Optional => {
+ if(a == null and b == null) return true;
+ if(a == null or b == null) return false;
+ return eql(a.?, b.?);
+ },
else => return a == b,
}
}
@@ -452,7 +484,7 @@ test "std.meta.eql" {
const U = union(enum) {
s: S,
- f: f32,
+ f: ?f32,
};
const s_1 = S{
std/meta/trait.zig
@@ -231,6 +231,37 @@ test "std.meta.trait.isPacked" {
debug.assert(!isPacked(u8));
}
+///
+pub fn isUnsignedInt(comptime T: type) bool {
+ return switch (@typeId(T)) {
+ builtin.TypeId.Int => !@typeInfo(T).Int.is_signed,
+ else => false,
+ };
+}
+
+test "isUnsignedInt" {
+ debug.assert(isUnsignedInt(u32) == true);
+ debug.assert(isUnsignedInt(comptime_int) == false);
+ debug.assert(isUnsignedInt(i64) == false);
+ debug.assert(isUnsignedInt(f64) == false);
+}
+
+///
+pub fn isSignedInt(comptime T: type) bool {
+ return switch (@typeId(T)) {
+ builtin.TypeId.ComptimeInt => true,
+ builtin.TypeId.Int => @typeInfo(T).Int.is_signed,
+ else => false,
+ };
+}
+
+test "isSignedInt" {
+ debug.assert(isSignedInt(u32) == false);
+ debug.assert(isSignedInt(comptime_int) == true);
+ debug.assert(isSignedInt(i64) == true);
+ debug.assert(isSignedInt(f64) == false);
+}
+
///
pub fn isSingleItemPtr(comptime T: type) bool {
if (comptime is(builtin.TypeId.Pointer)(T)) {
std/io.zig
@@ -8,6 +8,8 @@ const debug = std.debug;
const assert = debug.assert;
const os = std.os;
const mem = std.mem;
+const meta = std.meta;
+const trait = meta.trait;
const Buffer = std.Buffer;
const fmt = std.fmt;
const File = std.os.File;
@@ -444,6 +446,151 @@ pub const SliceInStream = struct {
}
};
+/// Creates a stream which allows for reading bit fields from another stream
+pub fn BitInStream(endian: builtin.Endian, comptime Error: type) type {
+ return struct {
+ const Self = @This();
+
+ in_stream: *Stream,
+ bit_buffer: u7,
+ bit_count: u3,
+ stream: Stream,
+
+ pub const Stream = InStream(Error);
+ const u8_bit_count = comptime meta.bitCount(u8);
+ const u7_bit_count = comptime meta.bitCount(u7);
+ const u4_bit_count = comptime meta.bitCount(u4);
+
+ pub fn init(in_stream: *Stream) Self {
+ return Self{
+ .in_stream = in_stream,
+ .bit_buffer = 0,
+ .bit_count = 0,
+ .stream = Stream{ .readFn = read },
+ };
+ }
+
+ /// Reads `bits` bits from the stream and returns a specified unsigned int type
+ /// containing them in the least significant end, returning an error if the
+ /// specified number of bits could not be read.
+ pub fn readBitsNoEof(self: *Self, comptime U: type, bits: usize) !U {
+ var n: usize = undefined;
+ const result = try self.readBits(U, bits, &n);
+ if (n < bits) return error.EndOfStream;
+ return result;
+ }
+
+ /// Reads `bits` bits from the stream and returns a specified unsigned int type
+ /// containing them in the least significant end. The number of bits successfully
+ /// read is placed in `out_bits`, as reaching the end of the stream is not an error.
+ pub fn readBits(self: *Self, comptime U: type, bits: usize, out_bits: *usize) Error!U {
+ debug.assert(trait.isUnsignedInt(U));
+
+ //by extending the buffer to a minimum of u8 we can cover a number of edge cases
+ // related to shifting and casting.
+ const u_bit_count = comptime meta.bitCount(U);
+ const buf_bit_count = bc: {
+ debug.assert(u_bit_count >= bits);
+ break :bc if (u_bit_count <= u8_bit_count) u8_bit_count else u_bit_count;
+ };
+ const Buf = @IntType(false, buf_bit_count);
+ const BufShift = math.Log2Int(Buf);
+
+ out_bits.* = usize(0);
+ if (U == u0 or bits == 0) return 0;
+ var out_buffer = Buf(0);
+
+ if (self.bit_count > 0) {
+ const n = if (self.bit_count >= bits) @intCast(u3, bits) else self.bit_count;
+ const shift = u7_bit_count - n;
+ switch (endian) {
+ builtin.Endian.Big => {
+ out_buffer = Buf(self.bit_buffer >> shift);
+ self.bit_buffer <<= n;
+ },
+ builtin.Endian.Little => {
+ const value = (self.bit_buffer << shift) >> shift;
+ out_buffer = Buf(value);
+ self.bit_buffer >>= n;
+ },
+ }
+ self.bit_count -= n;
+ out_bits.* = n;
+ }
+ //at this point we know bit_buffer is empty
+
+ //copy bytes until we have enough bits, then leave the rest in bit_buffer
+ while (out_bits.* < bits) {
+ const n = bits - out_bits.*;
+ const next_byte = self.in_stream.readByte() catch |err| {
+ if (err == error.EndOfStream) {
+ return @intCast(U, out_buffer);
+ }
+ return err;
+ };
+
+ switch (endian) {
+ builtin.Endian.Big => {
+ if (n >= u8_bit_count) {
+ out_buffer <<= @intCast(u3, u8_bit_count - 1);
+ out_buffer <<= 1;
+ out_buffer |= Buf(next_byte);
+ out_bits.* += u8_bit_count;
+ continue;
+ }
+
+ const shift = @intCast(u3, u8_bit_count - n);
+ out_buffer <<= @intCast(BufShift, n);
+ out_buffer |= Buf(next_byte >> shift);
+ out_bits.* += n;
+ self.bit_buffer = @truncate(u7, next_byte << @intCast(u3, n - 1));
+ self.bit_count = shift;
+ },
+ builtin.Endian.Little => {
+ if (n >= u8_bit_count) {
+ out_buffer |= Buf(next_byte) << @intCast(BufShift, out_bits.*);
+ out_bits.* += u8_bit_count;
+ continue;
+ }
+
+ const shift = @intCast(u3, u8_bit_count - n);
+ const value = (next_byte << shift) >> shift;
+ out_buffer |= Buf(value) << @intCast(BufShift, out_bits.*);
+ out_bits.* += n;
+ self.bit_buffer = @truncate(u7, next_byte >> @intCast(u3, n));
+ self.bit_count = shift;
+ },
+ }
+ }
+
+ return @intCast(U, out_buffer);
+ }
+
+ pub fn alignToByte(self: *Self) void {
+ self.bit_buffer = 0;
+ self.bit_count = 0;
+ }
+
+ pub fn read(self_stream: *Stream, buffer: []u8) Error!usize {
+ var self = @fieldParentPtr(Self, "stream", self_stream);
+
+ var out_bits: usize = undefined;
+ var out_bits_total = usize(0);
+ //@NOTE: I'm not sure this is a good idea, maybe alignToByte should be forced
+ if (self.bit_count > 0) {
+ for (buffer) |*b, i| {
+ b.* = try self.readBits(u8, u8_bit_count, &out_bits);
+ out_bits_total += out_bits;
+ }
+ const incomplete_byte = @boolToInt(out_bits_total % u8_bit_count > 0);
+ return (out_bits_total / u8_bit_count) + incomplete_byte;
+ }
+
+ return self.in_stream.read(buffer);
+ }
+ };
+}
+
/// This is a simple OutStream that writes to a slice, and returns an error
/// when it runs out of space.
pub const SliceOutStream = struct {
@@ -637,6 +784,137 @@ pub const BufferOutStream = struct {
}
};
+/// Creates a stream which allows for writing bit fields to another stream
+pub fn BitOutStream(endian: builtin.Endian, comptime Error: type) type {
+ return struct {
+ const Self = @This();
+
+ out_stream: *Stream,
+ bit_buffer: u8,
+ bit_count: u4,
+ stream: Stream,
+
+ pub const Stream = OutStream(Error);
+ const u8_bit_count = comptime meta.bitCount(u8);
+ const u4_bit_count = comptime meta.bitCount(u4);
+
+ pub fn init(out_stream: *Stream) Self {
+ return Self{
+ .out_stream = out_stream,
+ .bit_buffer = 0,
+ .bit_count = 0,
+ .stream = Stream{ .writeFn = write },
+ };
+ }
+
+ /// Write the specified number of bits to the stream from the least significant bits of
+ /// the specified unsigned int value. Bits will only be written to the stream when there
+ /// are enough to fill a byte.
+ pub fn writeBits(self: *Self, value: var, bits: usize) Error!void {
+ if (bits == 0) return;
+
+ const U = @typeOf(value);
+ debug.assert(trait.isUnsignedInt(U));
+
+ //by extending the buffer to a minimum of u8 we can cover a number of edge cases
+ // related to shifting and casting.
+ const u_bit_count = comptime meta.bitCount(U);
+ const buf_bit_count = bc: {
+ debug.assert(u_bit_count >= bits);
+ break :bc if (u_bit_count <= u8_bit_count) u8_bit_count else u_bit_count;
+ };
+ const Buf = @IntType(false, buf_bit_count);
+ const BufShift = math.Log2Int(Buf);
+
+ const buf_value = @intCast(Buf, value);
+
+ const high_byte_shift = @intCast(BufShift, buf_bit_count - u8_bit_count);
+ var in_buffer = switch (endian) {
+ builtin.Endian.Big => buf_value << @intCast(BufShift, buf_bit_count - bits),
+ builtin.Endian.Little => buf_value,
+ };
+ var in_bits = bits;
+
+ if (self.bit_count > 0) {
+ const bits_remaining = u8_bit_count - self.bit_count;
+ const n = @intCast(u3, if (bits_remaining > bits) bits else bits_remaining);
+ switch (endian) {
+ builtin.Endian.Big => {
+ const shift = @intCast(BufShift, high_byte_shift + self.bit_count);
+ const v = @intCast(u8, in_buffer >> shift);
+ self.bit_buffer |= v;
+ in_buffer <<= n;
+ },
+ builtin.Endian.Little => {
+ const v = @truncate(u8, in_buffer) << @intCast(u3, self.bit_count);
+ self.bit_buffer |= v;
+ in_buffer >>= n;
+ },
+ }
+ self.bit_count += n;
+ in_bits -= n;
+
+ //if we didn't fill the buffer, it's because bits < bits_remaining;
+ if (self.bit_count != u8_bit_count) return;
+ try self.out_stream.writeByte(self.bit_buffer);
+ self.bit_buffer = 0;
+ self.bit_count = 0;
+ }
+ //at this point we know bit_buffer is empty
+
+ //copy bytes until we can't fill one anymore, then leave the rest in bit_buffer
+ while (in_bits >= u8_bit_count) {
+ switch (endian) {
+ builtin.Endian.Big => {
+ const v = @intCast(u8, in_buffer >> high_byte_shift);
+ try self.out_stream.writeByte(v);
+ in_buffer <<= @intCast(u3, u8_bit_count - 1);
+ in_buffer <<= 1;
+ },
+ builtin.Endian.Little => {
+ const v = @truncate(u8, in_buffer);
+ try self.out_stream.writeByte(v);
+ in_buffer >>= @intCast(u3, u8_bit_count - 1);
+ in_buffer >>= 1;
+ },
+ }
+ in_bits -= u8_bit_count;
+ }
+
+ if (in_bits > 0) {
+ self.bit_count = @intCast(u4, in_bits);
+ self.bit_buffer = switch (endian) {
+ builtin.Endian.Big => @truncate(u8, in_buffer >> high_byte_shift),
+ builtin.Endian.Little => @truncate(u8, in_buffer),
+ };
+ }
+ }
+
+ /// Flush any remaining bits to the stream.
+ pub fn flushBits(self: *Self) !void {
+ if (self.bit_count == 0) return;
+ try self.out_stream.writeByte(self.bit_buffer);
+ self.bit_buffer = 0;
+ self.bit_count = 0;
+ }
+
+ pub fn write(self_stream: *Stream, buffer: []const u8) Error!void {
+ var self = @fieldParentPtr(Self, "stream", self_stream);
+
+ //@NOTE: I'm not sure this is a good idea, maybe flushBits should be forced
+ if (self.bit_count > 0) {
+ for (buffer) |b, i|
+ try self.writeBits(b, u8_bit_count);
+ return;
+ }
+
+ return self.out_stream.write(buffer);
+ }
+ };
+}
+
+
+
pub const BufferedAtomicFile = struct {
atomic_file: os.AtomicFile,
file_stream: os.File.OutStream,
@@ -677,11 +955,6 @@ pub const BufferedAtomicFile = struct {
}
};
-test "import io tests" {
- comptime {
- _ = @import("io_test.zig");
- }
-}
pub fn readLine(buf: *std.Buffer) ![]u8 {
var stdin = try getStdIn();
@@ -753,3 +1026,359 @@ test "io.readLineSliceFrom" {
debug.assert(mem.eql(u8, "Line 1", try readLineSliceFrom(stream, buf[0..])));
debug.assertError(readLineSliceFrom(stream, buf[0..]), error.OutOfMemory);
}
+
+/// Creates a deserializer that deserializes types from any stream.
+/// If `is_packed` is true, the data stream is treated as bit-packed,
+/// otherwise data is expected to be packed to the smallest byte.
+/// Types may implement a custom deserialization routine with a
+/// function named `deserialize` in the form of:
+/// pub fn deserialize(self: *Self, deserializer: var) !void
+/// which will be called when the deserializer is used to deserialize
+/// that type. It will pass a pointer to the type instance to deserialize
+/// into and a pointer to the deserializer struct.
+pub fn Deserializer(endian: builtin.Endian, is_packed: bool, comptime Error: type) type {
+ return struct {
+ const Self = @This();
+
+ in_stream: if (is_packed) BitInStream(endian, Stream.Error) else *Stream,
+
+ pub const Stream = InStream(Error);
+
+ pub fn init(in_stream: *Stream) Self {
+ return Self{ .in_stream = switch (is_packed) {
+ true => BitInStream(endian, Stream.Error).init(in_stream),
+ else => in_stream,
+ } };
+ }
+
+ //@BUG: inferred error issue
+ fn deserializeInt(self: *Self, comptime T: type) (Stream.Error || error{EndOfStream})!T {
+ debug.assert(trait.is(builtin.TypeId.Int)(T) or trait.is(builtin.TypeId.Float)(T));
+
+ const u8_bit_count = comptime meta.bitCount(u8);
+ const t_bit_count = comptime meta.bitCount(T);
+
+ const U = @IntType(false, t_bit_count);
+ const Log2U = math.Log2Int(U);
+ const int_size = @sizeOf(U);
+
+ if (is_packed) {
+ const result = try self.in_stream.readBitsNoEof(U, t_bit_count);
+ return @bitCast(T, result);
+ }
+
+ var buffer: [int_size]u8 = undefined;
+ const read_size = try self.in_stream.read(buffer[0..]);
+ if (read_size < int_size) return error.EndOfStream;
+
+ if (int_size == 1) return @bitCast(T, buffer[0]);
+
+ var result = U(0);
+ for (buffer) |byte, i| {
+ switch (endian) {
+ builtin.Endian.Big => {
+ result = (result << @intCast(u4, u8_bit_count)) | byte;
+ },
+ builtin.Endian.Little => {
+ result |= U(byte) << @intCast(Log2U, u8_bit_count * i);
+ },
+ }
+ }
+
+ return @bitCast(T, result);
+ }
+
+ //@TODO: Replace this with @unionInit or whatever when it is added
+ // see: #1315
+ fn setTag(ptr: var, tag: var) void {
+ const T = @typeOf(ptr);
+ comptime debug.assert(trait.isPtrTo(builtin.TypeId.Union)(T));
+ const U = meta.Child(T);
+
+ const info = @typeInfo(U).Union;
+ if (info.tag_type) |TagType| {
+ debug.assert(TagType == @typeOf(tag));
+
+ var ptr_tag = ptr: {
+ if (@alignOf(TagType) >= @alignOf(U)) break :ptr @ptrCast(*TagType, ptr);
+ const offset = comptime max: {
+ var max_field_size: comptime_int = 0;
+ for (info.fields) |field_info| {
+ const field_size = @sizeOf(field_info.field_type);
+ max_field_size = math.max(max_field_size, field_size);
+ }
+ break :max math.max(max_field_size, @alignOf(U));
+ };
+ break :ptr @intToPtr(*TagType, @ptrToInt(ptr) + offset);
+ };
+ ptr_tag.* = tag;
+ }
+ }
+
+ /// Deserializes and returns data of the specified type from the stream
+ pub fn deserialize(self: *Self, comptime T: type) !T {
+ var value: T = undefined;
+ try self.deserializeInto(&value);
+ return value;
+ }
+
+ /// Deserializes data into the type pointed to by `ptr`
+ pub fn deserializeInto(self: *Self, ptr: var) !void {
+ const T = @typeOf(ptr);
+ debug.assert(trait.is(builtin.TypeId.Pointer)(T));
+
+ if (comptime trait.isSlice(T) or comptime trait.isPtrTo(builtin.TypeId.Array)(T)) {
+ for (ptr) |*v|
+ try self.deserializeInto(v);
+ return;
+ }
+
+ comptime debug.assert(trait.isSingleItemPtr(T));
+
+ const C = comptime meta.Child(T);
+ const child_type_id = @typeId(C);
+
+ //custom deserializer: fn(self: *Self, deserializer: var) !void
+ if (comptime trait.hasFn("deserialize")(C)) return ptr.deserialize(self);
+
+ if (comptime trait.isPacked(C) and !is_packed) {
+ var packed_deserializer = Deserializer(endian, true, Error).init(self.in_stream);
+ return packed_deserializer.deserializeInto(ptr);
+ }
+
+ switch (child_type_id) {
+ builtin.TypeId.Void => return,
+ builtin.TypeId.Bool => ptr.* = (try self.deserializeInt(u1)) > 0,
+ builtin.TypeId.Float, builtin.TypeId.Int => ptr.* = try self.deserializeInt(C),
+ builtin.TypeId.Struct => {
+ const info = @typeInfo(C).Struct;
+
+ inline for (info.fields) |*field_info| {
+ const name = field_info.name;
+ const FieldType = field_info.field_type;
+
+ if (FieldType == void or FieldType == u0) continue;
+
+ //it doesn't make any sense to read pointers
+ if (comptime trait.is(builtin.TypeId.Pointer)(FieldType)) {
+ @compileError("Will not " ++ "read field " ++ name ++ " of struct " ++
+ @typeName(C) ++ " because it " ++ "is of pointer-type " ++
+ @typeName(FieldType) ++ ".");
+ }
+
+ try self.deserializeInto(&@field(ptr, name));
+ }
+ },
+ builtin.TypeId.Union => {
+ const info = @typeInfo(C).Union;
+ if (info.tag_type) |TagType| {
+ //we avoid duplicate iteration over the enum tags
+ // by getting the int directly and casting it without
+ // safety. If it is bad, it will be caught anyway.
+ const TagInt = @TagType(TagType);
+ const tag = try self.deserializeInt(TagInt);
+
+ {
+ @setRuntimeSafety(false);
+ //See: #1315
+ setTag(ptr, @intToEnum(TagType, tag));
+ }
+
+ inline for (info.fields) |field_info| {
+ if (field_info.enum_field.?.value == tag) {
+ const name = field_info.name;
+ const FieldType = field_info.field_type;
+ @field(ptr, name) = FieldType(undefined);
+ try self.deserializeInto(&@field(ptr, name));
+ return;
+ }
+ }
+ //This is reachable if the enum data is bad
+ return error.InvalidEnumTag;
+ }
+ @compileError("Cannot meaningfully deserialize " ++ @typeName(C) ++
+ " because it is an untagged union Use a custom deserialize().");
+ },
+ builtin.TypeId.Optional => {
+ const OC = comptime meta.Child(C);
+ const exists = (try self.deserializeInt(u1)) > 0;
+ if (!exists) {
+ ptr.* = null;
+ return;
+ }
+
+ //The way non-pointer optionals are implemented ensures a pointer to them
+ // will point to the value. The flag is stored at the end of that data.
+ var val_ptr = @ptrCast(*OC, ptr);
+ try self.deserializeInto(val_ptr);
+ //This bit ensures the null flag isn't set. Any actual copying should be
+ // optimized out... I hope.
+ ptr.* = val_ptr.*;
+ },
+ builtin.TypeId.Enum => {
+ var value = try self.deserializeInt(@TagType(C));
+ ptr.* = try meta.intToEnum(C, value);
+ },
+ else => {
+ @compileError("Cannot deserialize " ++ @tagName(child_type_id) ++ " types (unimplemented).");
+ },
+ }
+ }
+ };
+}
+
+/// Creates a serializer that serializes types to any stream.
+/// If `is_packed` is true, the data will be bit-packed into the stream.
+/// Note that the you must call `serializer.flush()` when you are done
+/// writing bit-packed data in order ensure any unwritten bits are committed.
+/// If `is_packed` is false, data is packed to the smallest byte. In the case
+/// of packed structs, the struct will written bit-packed and with the specified
+/// endianess, after which data will resume being written at the next byte boundary.
+/// Types may implement a custom serialization routine with a
+/// function named `serialize` in the form of:
+/// pub fn serialize(self: *const Self, serializer: var) !void
+/// which will be called when the serializer is used to serialize that type. It will
+/// pass a const pointer to the type instance to be serialized and a pointer
+/// to the serializer struct.
+pub fn Serializer(endian: builtin.Endian, is_packed: bool, comptime Error: type) type {
+ return struct {
+ const Self = @This();
+
+ out_stream: if (is_packed) BitOutStream(endian, Stream.Error) else *Stream,
+
+ pub const Stream = OutStream(Error);
+
+ pub fn init(out_stream: *Stream) Self {
+ return Self{ .out_stream = switch (is_packed) {
+ true => BitOutStream(endian, Stream.Error).init(out_stream),
+ else => out_stream,
+ } };
+ }
+
+ /// Flushes any unwritten bits to the stream
+ pub fn flush(self: *Self) Stream.Error!void {
+ if (is_packed) return self.out_stream.flushBits();
+ }
+
+ fn serializeInt(self: *Self, value: var) !void {
+ const T = @typeOf(value);
+ debug.assert(trait.is(builtin.TypeId.Int)(T) or trait.is(builtin.TypeId.Float)(T));
+
+ const t_bit_count = comptime meta.bitCount(T);
+ const u8_bit_count = comptime meta.bitCount(u8);
+
+ const U = @IntType(false, t_bit_count);
+ const Log2U = math.Log2Int(U);
+ const int_size = @sizeOf(U);
+
+ const u_value = @bitCast(U, value);
+
+ if (is_packed) return self.out_stream.writeBits(u_value, t_bit_count);
+
+ var buffer: [int_size]u8 = undefined;
+ if (int_size == 1) buffer[0] = u_value;
+
+ for (buffer) |*byte, i| {
+ const idx = switch (endian) {
+ builtin.Endian.Big => int_size - i - 1,
+ builtin.Endian.Little => i,
+ };
+ const shift = @intCast(Log2U, idx * u8_bit_count);
+ const v = u_value >> shift;
+ byte.* = if (t_bit_count < u8_bit_count) v else @truncate(u8, v);
+ }
+
+ try self.out_stream.write(buffer);
+ }
+
+ /// Serializes the passed value into the stream
+ pub fn serialize(self: *Self, value: var) !void {
+ const T = comptime @typeOf(value);
+
+ if (comptime trait.isIndexable(T)) {
+ for (value) |v|
+ try self.serialize(v);
+ return;
+ }
+
+ //custom serializer: fn(self: *const Self, serializer: var) !void
+ if (comptime trait.hasFn("serialize")(T)) return value.serialize(self);
+
+ if (comptime trait.isPacked(T) and !is_packed) {
+ var packed_serializer = Serializer(endian, true, Error).init(self.out_stream);
+ try packed_serializer.serialize(value);
+ try packed_serializer.flush();
+ return;
+ }
+
+ switch (@typeId(T)) {
+ builtin.TypeId.Void => return,
+ builtin.TypeId.Bool => try self.serializeInt(u1(@boolToInt(value))),
+ builtin.TypeId.Float, builtin.TypeId.Int => try self.serializeInt(value),
+ builtin.TypeId.Struct => {
+ const info = @typeInfo(T);
+
+ inline for (info.Struct.fields) |*field_info| {
+ const name = field_info.name;
+ const FieldType = field_info.field_type;
+
+ if (FieldType == void or FieldType == u0) continue;
+
+ //It doesn't make sense to write pointers
+ if (comptime trait.is(builtin.TypeId.Pointer)(FieldType)) {
+ @compileError("Will not " ++ "serialize field " ++ name ++
+ " of struct " ++ @typeName(T) ++ " because it " ++
+ "is of pointer-type " ++ @typeName(FieldType) ++ ".");
+ }
+ try self.serialize(@field(value, name));
+ }
+ },
+ builtin.TypeId.Union => {
+ const info = @typeInfo(T).Union;
+ if (info.tag_type) |TagType| {
+ const active_tag = meta.activeTag(value);
+ try self.serialize(active_tag);
+ //This inline loop is necessary because active_tag is a runtime
+ // value, but @field requires a comptime value. Our alternative
+ // is to check each field for a match
+ inline for (info.fields) |field_info| {
+ if (field_info.enum_field.?.value == @enumToInt(active_tag)) {
+ const name = field_info.name;
+ const FieldType = field_info.field_type;
+ try self.serialize(@field(value, name));
+ return;
+ }
+ }
+ unreachable;
+ }
+ @compileError("Cannot meaningfully serialize " ++ @typeName(T) ++
+ " because it is an untagged union Use a custom serialize().");
+ },
+ builtin.TypeId.Optional => {
+ if (value == null) {
+ try self.serializeInt(u1(@boolToInt(false)));
+ return;
+ }
+ try self.serializeInt(u1(@boolToInt(true)));
+
+ const OC = comptime meta.Child(T);
+
+ //The way non-pointer optionals are implemented ensures a pointer to them
+ // will point to the value. The flag is stored at the end of that data.
+ var val_ptr = @ptrCast(*const OC, &value);
+ try self.serialize(val_ptr.*);
+ },
+ builtin.TypeId.Enum => {
+ try self.serializeInt(@enumToInt(value));
+ },
+ else => @compileError("Cannot serialize " ++ @tagName(@typeId(T)) ++ " types (unimplemented)."),
+ }
+ }
+ };
+}
+
+test "import io tests" {
+ comptime {
+ _ = @import("io_test.zig");
+ }
+}
std/io_test.zig
@@ -1,5 +1,7 @@
const std = @import("index.zig");
const io = std.io;
+const meta = std.meta;
+const trait = std.trait;
const DefaultPrng = std.rand.DefaultPrng;
const assert = std.debug.assert;
const assertError = std.debug.assertError;
@@ -132,3 +134,330 @@ test "SliceOutStream" {
assertError(ss.stream.write("Hello world!"), error.OutOfSpace);
assert(mem.eql(u8, ss.getWritten(), "Hello worl"));
}
+
+test "BitInStream" {
+ const mem_be = []u8{ 0b11001101, 0b00001011 };
+ const mem_le = []u8{ 0b00011101, 0b10010101 };
+
+ var mem_in_be = io.SliceInStream.init(mem_be[0..]);
+ const InError = io.SliceInStream.Error;
+ var bit_stream_be = io.BitInStream(builtin.Endian.Big, InError).init(&mem_in_be.stream);
+
+ var out_bits: usize = undefined;
+
+ assert(1 == try bit_stream_be.readBits(u2, 1, &out_bits));
+ assert(out_bits == 1);
+ assert(2 == try bit_stream_be.readBits(u5, 2, &out_bits));
+ assert(out_bits == 2);
+ assert(3 == try bit_stream_be.readBits(u128, 3, &out_bits));
+ assert(out_bits == 3);
+ assert(4 == try bit_stream_be.readBits(u8, 4, &out_bits));
+ assert(out_bits == 4);
+ assert(5 == try bit_stream_be.readBits(u9, 5, &out_bits));
+ assert(out_bits == 5);
+ assert(1 == try bit_stream_be.readBits(u1, 1, &out_bits));
+ assert(out_bits == 1);
+
+ mem_in_be.pos = 0;
+ bit_stream_be.bit_count = 0;
+ assert(0b110011010000101 == try bit_stream_be.readBits(u15, 15, &out_bits));
+ assert(out_bits == 15);
+
+ mem_in_be.pos = 0;
+ bit_stream_be.bit_count = 0;
+ assert(0b1100110100001011 == try bit_stream_be.readBits(u16, 16, &out_bits));
+ assert(out_bits == 16);
+
+ _ = try bit_stream_be.readBits(u0, 0, &out_bits);
+
+ var mem_in_le = io.SliceInStream.init(mem_le[0..]);
+ var bit_stream_le = io.BitInStream(builtin.Endian.Little, InError).init(&mem_in_le.stream);
+
+ assert(1 == try bit_stream_le.readBits(u2, 1, &out_bits));
+ assert(out_bits == 1);
+ assert(2 == try bit_stream_le.readBits(u5, 2, &out_bits));
+ assert(out_bits == 2);
+ assert(3 == try bit_stream_le.readBits(u128, 3, &out_bits));
+ assert(out_bits == 3);
+ assert(4 == try bit_stream_le.readBits(u8, 4, &out_bits));
+ assert(out_bits == 4);
+ assert(5 == try bit_stream_le.readBits(u9, 5, &out_bits));
+ assert(out_bits == 5);
+ assert(1 == try bit_stream_le.readBits(u1, 1, &out_bits));
+ assert(out_bits == 1);
+
+ mem_in_le.pos = 0;
+ bit_stream_le.bit_count = 0;
+ assert(0b001010100011101 == try bit_stream_le.readBits(u15, 15, &out_bits));
+ assert(out_bits == 15);
+
+ mem_in_le.pos = 0;
+ bit_stream_le.bit_count = 0;
+ assert(0b1001010100011101 == try bit_stream_le.readBits(u16, 16, &out_bits));
+ assert(out_bits == 16);
+
+ _ = try bit_stream_le.readBits(u0, 0, &out_bits);
+}
+
+test "BitOutStream" {
+ var mem_be = []u8{0} ** 2;
+ var mem_le = []u8{0} ** 2;
+
+ var mem_out_be = io.SliceOutStream.init(mem_be[0..]);
+ const OutError = io.SliceOutStream.Error;
+ var bit_stream_be = io.BitOutStream(builtin.Endian.Big, OutError).init(&mem_out_be.stream);
+
+ try bit_stream_be.writeBits(u2(1), 1);
+ try bit_stream_be.writeBits(u5(2), 2);
+ try bit_stream_be.writeBits(u128(3), 3);
+ try bit_stream_be.writeBits(u8(4), 4);
+ try bit_stream_be.writeBits(u9(5), 5);
+ try bit_stream_be.writeBits(u1(1), 1);
+
+ assert(mem_be[0] == 0b11001101 and mem_be[1] == 0b00001011);
+
+ mem_out_be.pos = 0;
+
+ try bit_stream_be.writeBits(u15(0b110011010000101), 15);
+ try bit_stream_be.flushBits();
+ assert(mem_be[0] == 0b11001101 and mem_be[1] == 0b00001010);
+
+ mem_out_be.pos = 0;
+ try bit_stream_be.writeBits(u32(0b110011010000101), 16);
+ assert(mem_be[0] == 0b01100110 and mem_be[1] == 0b10000101);
+
+ try bit_stream_be.writeBits(u0(0), 0);
+
+ var mem_out_le = io.SliceOutStream.init(mem_le[0..]);
+ var bit_stream_le = io.BitOutStream(builtin.Endian.Little, OutError).init(&mem_out_le.stream);
+
+ try bit_stream_le.writeBits(u2(1), 1);
+ try bit_stream_le.writeBits(u5(2), 2);
+ try bit_stream_le.writeBits(u128(3), 3);
+ try bit_stream_le.writeBits(u8(4), 4);
+ try bit_stream_le.writeBits(u9(5), 5);
+ try bit_stream_le.writeBits(u1(1), 1);
+
+ assert(mem_le[0] == 0b00011101 and mem_le[1] == 0b10010101);
+
+ mem_out_le.pos = 0;
+ try bit_stream_le.writeBits(u15(0b110011010000101), 15);
+ try bit_stream_le.flushBits();
+ assert(mem_le[0] == 0b10000101 and mem_le[1] == 0b01100110);
+
+ mem_out_le.pos = 0;
+ try bit_stream_le.writeBits(u32(0b1100110100001011), 16);
+ assert(mem_le[0] == 0b00001011 and mem_le[1] == 0b11001101);
+
+ try bit_stream_le.writeBits(u0(0), 0);
+}
+
+fn testIntSerializerDeserializer(comptime endian: builtin.Endian, comptime is_packed: bool) !void {
+ const max_test_bitsize = 17;
+
+ const total_bytes = comptime blk: {
+ var bytes = 0;
+ comptime var i = 0;
+ while (i <= max_test_bitsize) : (i += 1) bytes += (i / 8) + @boolToInt(i % 8 > 0);
+ break :blk bytes * 2;
+ };
+
+ var data_mem: [total_bytes]u8 = undefined;
+ var out = io.SliceOutStream.init(data_mem[0..]);
+ const OutError = io.SliceOutStream.Error;
+ var out_stream = &out.stream;
+ var serializer = io.Serializer(endian, is_packed, OutError).init(out_stream);
+
+ var in = io.SliceInStream.init(data_mem[0..]);
+ const InError = io.SliceInStream.Error;
+ var in_stream = &in.stream;
+ var deserializer = io.Deserializer(endian, is_packed, InError).init(in_stream);
+
+ comptime var i = 0;
+ inline while (i <= max_test_bitsize) : (i += 1) {
+ const U = @IntType(false, i);
+ const S = @IntType(true, i);
+ try serializer.serializeInt(U(i));
+ if (i != 0) try serializer.serializeInt(S(-1));
+ }
+ try serializer.flush();
+
+ i = 0;
+ inline while (i <= max_test_bitsize) : (i += 1) {
+ const U = @IntType(false, i);
+ const S = @IntType(true, i);
+ const x = try deserializer.deserializeInt(U);
+ const y = if (i != 0) try deserializer.deserializeInt(S);
+ assert(x == U(i));
+ if (i != 0) assert(y == S(-1));
+ }
+
+ const u8_bit_count = comptime meta.bitCount(u8);
+ //0 + 1 + 2 + ... n = (n * (n + 1)) / 2
+ //and we have each for unsigned and signed, so * 2
+ const total_bits = (max_test_bitsize * (max_test_bitsize + 1));
+ const extra_packed_byte = @boolToInt(total_bits % u8_bit_count > 0);
+ const total_packed_bytes = (total_bits / u8_bit_count) + extra_packed_byte;
+
+
+
+ assert(in.pos == if (is_packed) total_packed_bytes else total_bytes);
+}
+
+test "Serializer/Deserializer Int" {
+ try testIntSerializerDeserializer(builtin.Endian.Big, false);
+ try testIntSerializerDeserializer(builtin.Endian.Little, false);
+ try testIntSerializerDeserializer(builtin.Endian.Big, true);
+ try testIntSerializerDeserializer(builtin.Endian.Little, true);
+}
+
+fn testSerializerDeserializer(comptime endian: builtin.Endian, comptime is_packed: bool) !void {
+ const ColorType = enum(u4) {
+ RGB8 = 1,
+ RA16 = 2,
+ R32 = 3,
+ };
+
+ const TagAlign = union(enum(u32)) {
+ A: u8,
+ B: u8,
+ C: u8,
+ };
+
+ const Color = union(ColorType) {
+ RGB8: struct {
+ r: u8,
+ g: u8,
+ b: u8,
+ a: u8,
+ },
+ RA16: struct {
+ r: u16,
+ a: u16,
+ },
+ R32: u32,
+ };
+
+ const PackedStruct = packed struct {
+ f_i3: i3,
+ f_u2: u2,
+ };
+
+ //to test custom serialization
+ const Custom = struct {
+ f_f16: f16,
+ f_unused_u32: u32,
+
+ pub fn deserialize(self: *@This(), deserializer: var) !void {
+ try deserializer.deserializeInto(&self.f_f16);
+ self.f_unused_u32 = 47;
+ }
+
+ pub fn serialize(self: *const @This(), serializer: var) !void {
+ try serializer.serialize(self.f_f16);
+ }
+ };
+
+ const MyStruct = struct {
+ f_i3: i3,
+ f_u8: u8,
+ f_tag_align: TagAlign,
+ f_u24: u24,
+ f_i19: i19,
+ f_void: void,
+ f_f32: f32,
+ f_f128: f128,
+ f_packed_0: PackedStruct,
+ f_i7arr: [10]i7,
+ f_of64n: ?f64,
+ f_of64v: ?f64,
+ f_color_type: ColorType,
+ f_packed_1: PackedStruct,
+ f_custom: Custom,
+ f_color: Color,
+ };
+
+ const my_inst = MyStruct{
+ .f_i3 = -1,
+ .f_u8 = 8,
+ .f_tag_align = TagAlign{ .B = 148 },
+ .f_u24 = 24,
+ .f_i19 = 19,
+ .f_void = {},
+ .f_f32 = 32.32,
+ .f_f128 = 128.128,
+ .f_packed_0 = PackedStruct{ .f_i3 = -1, .f_u2 = 2 },
+ .f_i7arr = [10]i7{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
+ .f_of64n = null,
+ .f_of64v = 64.64,
+ .f_color_type = ColorType.R32,
+ .f_packed_1 = PackedStruct{ .f_i3 = 1, .f_u2 = 1 },
+ .f_custom = Custom{ .f_f16 = 38.63, .f_unused_u32 = 47 },
+ .f_color = Color{ .R32 = 123822 },
+ };
+
+ var data_mem: [@sizeOf(MyStruct)]u8 = undefined;
+ var out = io.SliceOutStream.init(data_mem[0..]);
+ const OutError = io.SliceOutStream.Error;
+ var out_stream = &out.stream;
+ var serializer = io.Serializer(endian, is_packed, OutError).init(out_stream);
+
+ var in = io.SliceInStream.init(data_mem[0..]);
+ const InError = io.SliceInStream.Error;
+ var in_stream = &in.stream;
+ var deserializer = io.Deserializer(endian, is_packed, InError).init(in_stream);
+
+ try serializer.serialize(my_inst);
+
+ const my_copy = try deserializer.deserialize(MyStruct);
+
+ assert(meta.eql(my_copy, my_inst));
+}
+
+test "Serializer/Deserializer generic" {
+ try testSerializerDeserializer(builtin.Endian.Big, false);
+ try testSerializerDeserializer(builtin.Endian.Little, false);
+ try testSerializerDeserializer(builtin.Endian.Big, true);
+ try testSerializerDeserializer(builtin.Endian.Little, true);
+}
+
+fn testBadData(comptime endian: builtin.Endian, comptime is_packed: bool) !void {
+ const E = enum(u14) {
+ One = 1,
+ Two = 2,
+ };
+
+ const A = struct {
+ e: E,
+ };
+
+ const C = union(E) {
+ One: u14,
+ Two: f16,
+ };
+
+ var data_mem: [4]u8 = undefined;
+ var out = io.SliceOutStream.init(data_mem[0..]);
+ const OutError = io.SliceOutStream.Error;
+ var out_stream = &out.stream;
+ var serializer = io.Serializer(endian, is_packed, OutError).init(out_stream);
+
+ var in = io.SliceInStream.init(data_mem[0..]);
+ const InError = io.SliceInStream.Error;
+ var in_stream = &in.stream;
+ var deserializer = io.Deserializer(endian, is_packed, InError).init(in_stream);
+
+ try serializer.serialize(u14(3));
+ assertError(deserializer.deserialize(A), error.InvalidEnumTag);
+ out.pos = 0;
+ try serializer.serialize(u14(3));
+ try serializer.serialize(u14(88));
+ assertError(deserializer.deserialize(C), error.InvalidEnumTag);
+}
+
+test "Deserializer bad data" {
+ try testBadData(builtin.Endian.Big, false);
+ try testBadData(builtin.Endian.Little, false);
+ try testBadData(builtin.Endian.Big, true);
+ try testBadData(builtin.Endian.Little, true);
+}
\ No newline at end of file