neurocyte/cbor
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refactor: reduce writeTypedVal to a single write call

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Also, use the very cool std.mem.writeInt to avoid endianess issues.
This commit is contained in:
CJ van den Berg 2026-03-12 20:16:49 +01:00
parent 301e96f75d
commit 30e260bcea
Signed by: neurocyte
GPG key ID: 8EB1E1BB660E3FB9
1 changed files with 22 additions and 26 deletions
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48
src/cbor.zig
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@ -93,32 +93,28 @@ fn write(writer: *Io.Writer, value: u8) Io.Writer.Error!void {
fn writeTypedVal(writer: *Io.Writer, type_: u8, value: u64) Io.Writer.Error!void {
const t: u8 = type_ << 5;
if (value < 24) {
try write(writer, t | @as(u8, @truncate(value)));
} else if (value < 256) {
try write(writer, t | 24);
try write(writer, @as(u8, @truncate(value)));
} else if (value < 65536) {
try write(writer, t | 25);
try write(writer, @as(u8, @truncate(value >> 8)));
try write(writer, @as(u8, @truncate(value)));
} else if (value < 4294967296) {
try write(writer, t | 26);
try write(writer, @as(u8, @truncate(value >> 24)));
try write(writer, @as(u8, @truncate(value >> 16)));
try write(writer, @as(u8, @truncate(value >> 8)));
try write(writer, @as(u8, @truncate(value)));
} else {
try write(writer, t | 27);
try write(writer, @as(u8, @truncate(value >> 56)));
try write(writer, @as(u8, @truncate(value >> 48)));
try write(writer, @as(u8, @truncate(value >> 40)));
try write(writer, @as(u8, @truncate(value >> 32)));
try write(writer, @as(u8, @truncate(value >> 24)));
try write(writer, @as(u8, @truncate(value >> 16)));
try write(writer, @as(u8, @truncate(value >> 8)));
try write(writer, @as(u8, @truncate(value)));
}
var buf: [9]u8 = undefined;
const slice = if (value < 24) blk: {
buf[0] = t | @as(u8, @truncate(value));
break :blk buf[0..1];
} else if (value < 256) blk: {
buf[0] = t | 24;
buf[1] = @truncate(value);
break :blk buf[0..2];
} else if (value < 65536) blk: {
buf[0] = t | 25;
std.mem.writeInt(u16, buf[1..3], @truncate(value), .big);
break :blk buf[0..3];
} else if (value < 4294967296) blk: {
buf[0] = t | 26;
std.mem.writeInt(u32, buf[1..5], @truncate(value), .big);
break :blk buf[0..5];
} else blk: {
buf[0] = t | 27;
std.mem.writeInt(u64, buf[1..9], value, .big);
break :blk buf[0..9];
};
_ = try writer.write(slice);
}
pub fn writeArrayHeader(writer: *Io.Writer, sz: usize) Io.Writer.Error!void {