Source
pub fn format(
self: Ip6Address,
comptime fmt: []const u8,
options: std.fmt.FormatOptions,
out_stream: anytype,
) !void {
if (fmt.len != 0) std.fmt.invalidFmtError(fmt, self);
_ = options;
const port = mem.bigToNative(u16, self.sa.port);
if (mem.eql(u8, self.sa.addr[0..12], &[_]u8{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff })) {
try std.fmt.format(out_stream, "[::ffff:{}.{}.{}.{}]:{}", .{
self.sa.addr[12],
self.sa.addr[13],
self.sa.addr[14],
self.sa.addr[15],
port,
});
return;
}
const big_endian_parts = @as(*align(1) const [8]u16, @ptrCast(&self.sa.addr));
const native_endian_parts = switch (native_endian) {
.big => big_endian_parts.*,
.little => blk: {
var buf: [8]u16 = undefined;
for (big_endian_parts, 0..) |part, i| {
buf[i] = mem.bigToNative(u16, part);
}
break :blk buf;
},
};
// Find the longest zero run
var longest_start: usize = 8;
var longest_len: usize = 0;
var current_start: usize = 0;
var current_len: usize = 0;
for (native_endian_parts, 0..) |part, i| {
if (part == 0) {
if (current_len == 0) {
current_start = i;
}
current_len += 1;
if (current_len > longest_len) {
longest_start = current_start;
longest_len = current_len;
}
} else {
current_len = 0;
}
}
// Only compress if the longest zero run is 2 or more
if (longest_len < 2) {
longest_start = 8;
longest_len = 0;
}
try out_stream.writeAll("[");
var i: usize = 0;
var abbrv = false;
while (i < native_endian_parts.len) : (i += 1) {
if (i == longest_start) {
// Emit "::" for the longest zero run
if (!abbrv) {
try out_stream.writeAll(if (i == 0) "::" else ":");
abbrv = true;
}
i += longest_len - 1; // Skip the compressed range
continue;
}
if (abbrv) {
abbrv = false;
}
try std.fmt.format(out_stream, "{x}", .{native_endian_parts[i]});
if (i != native_endian_parts.len - 1) {
try out_stream.writeAll(":");
}
}
try std.fmt.format(out_stream, "]:{}", .{port});
}