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switch to io.Reader
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-27
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src/root.zig
+29
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src/root.zig
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const std = @import("std");
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const assert = std.debug.assert;
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const io = std.io;
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pub const BytePacketBuffer = struct {
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buf: [512]u8 = undefined,
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pos: usize = 0,
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pub const ReadError = error{EndOfBuffer};
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pub const Reader = io.Reader(*BytePacketBuffer, ReadError, read);
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/// Change the buffer position forward a specific number of steps
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pub fn step(self: *BytePacketBuffer, pos: usize) void {
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self.pos = pos;
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}
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pub fn reader(self: *BytePacketBuffer) Reader {
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return .{ .context = self };
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}
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/// Read a single byte and move the position one step forward
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pub fn read(self: *BytePacketBuffer) error{EndOfBuffer}!u8 {
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if (self.pos >= comptime self.buf.len) return error.EndOfBuffer;
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const res = self.buf[self.pos];
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self.pos += 1;
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return res;
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pub fn read(self: *BytePacketBuffer, dest: []u8) ReadError!usize {
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const size = @min(dest.len, self.buf.len - self.pos);
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const end = self.pos + size;
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@memcpy(dest[0..size], self.buf[self.pos..end]);
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self.pos = end;
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return size;
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}
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/// Get a single byte without changing the buffer position
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pub fn get(self: *const BytePacketBuffer, pos: usize) error{EndOfBuffer}!u8 {
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if (pos >= comptime self.buf.len) return error.EndOfBuffer;
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pub fn get(self: *const BytePacketBuffer, pos: usize) ReadError!u8 {
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if (pos >= comptime self.buf.len) return ReadError.EndOfBuffer;
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return self.buf[pos];
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}
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/// Get a range of bytes
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pub fn get_range(self: *const BytePacketBuffer, start: usize, len: usize) error{EndOfBuffer}![]const u8 {
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if (start + len >= comptime self.buf.len) return error.EndOfBuffer;
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pub fn get_range(self: *const BytePacketBuffer, start: usize, len: usize) ReadError![]const u8 {
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if (start + len >= comptime self.buf.len) return ReadError.EndOfBuffer;
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return self.buf[start .. start + len];
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}
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/// Read two bytes, stepping two steps forward
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pub fn read_u16(self: *BytePacketBuffer) error{EndOfBuffer}!u16 {
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return (@as(u16, try self.read()) << 8) |
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@as(u16, try self.read());
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}
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/// Read two bytes, stepping two steps forward
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pub fn read_u32(self: *BytePacketBuffer) error{EndOfBuffer}!u32 {
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return @as(u32, try self.read()) << 24 |
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(@as(u32, try self.read()) << 16) |
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(@as(u32, try self.read()) << 8) |
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(@as(u32, try self.read()));
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}
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/// Read a qname
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///
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/// The tricky part: Reading domain names, taking labels into consideration.
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continue;
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} else {
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// Move a single byte forward to move path the length
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self.pos += 1;
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pos += 1;
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// Domain names are terminated by an empty label of length 0, so if the length
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out_pos += del.len;
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}
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@memcpy(outstr[out_pos .. out_pos + len], try self.get_range(pos, len));
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const read_len = try self.read(outstr[out_pos .. out_pos + len]);
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assert(read_len == len);
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delim = ".";
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pos += len;
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const testing = std.testing;
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var buf = BytePacketBuffer{};
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buf.buf[0] = 0x1;
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try testing.expectEqual(0x1, try buf.read());
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try testing.expectEqual(0x1, try buf.reader().readInt(u8, .big));
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}
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test "BytePacketBuffer.read_u16" {
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var buf = BytePacketBuffer{};
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buf.buf[0] = 0x1;
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buf.buf[1] = 0x1;
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try testing.expectEqual(0x101, try buf.read_u16());
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try testing.expectEqual(0x101, try buf.reader().readInt(u16, .big));
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}
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test "BytePacketBuffer.read_u32" {
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buf.buf[1] = 0x1;
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buf.buf[2] = 0x1;
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buf.buf[3] = 0x1;
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try testing.expectEqual(0x1010101, try buf.read_u32());
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try testing.expectEqual(0x1010101, try buf.reader().readInt(u32, .big));
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}
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test "BytePacketBuffer.read_qname" {