this repo has no description
irc: use faster case folding
Do casefold matching by finding differences instead of turning each
string into lowercase
+29
-24
+29
-24
src/irc.zig
+29
-24
src/irc.zig
···
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}
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pub fn getOrCreateChannel(self: *Client, name: []const u8) !*Channel {
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const name_lower = try self.alloc.alloc(u8, name.len);
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defer self.alloc.free(name_lower);
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try caseMap(name_lower, name, .rfc1459);
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for (self.channels.items) |*channel| {
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const chan_lower = try self.alloc.alloc(u8, channel.name.len);
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defer self.alloc.free(chan_lower);
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try caseMap(chan_lower, channel.name, .rfc1459);
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if (std.mem.eql(u8, name_lower, chan_lower)) return channel;
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if (caseFold(name, channel.name)) return channel;
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}
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const channel: Channel = .{
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.name = try self.alloc.dupe(u8, name),
···
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rfc1459_strict,
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};
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-
pub fn caseMap(out: []u8, str: []const u8, algo: CaseMapAlgo) !void {
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assert(out.len == str.len);
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pub fn caseMap(char: u8, algo: CaseMapAlgo) u8 {
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switch (algo) {
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.ascii => {
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for (str, 0..) |b, i| {
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switch (b) {
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'A'...'Z' => out[i] = b + 0x20,
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else => out[i] = b,
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}
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switch (char) {
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'A'...'Z' => return char + 0x20,
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else => return char,
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}
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},
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.rfc1459 => {
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for (str, 0..) |b, i| {
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switch (b) {
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'A'...'^' => out[i] = b + 0x20,
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else => out[i] = b,
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}
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switch (char) {
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'A'...'^' => return char + 0x20,
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else => return char,
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}
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},
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.rfc1459_strict => {
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for (str, 0..) |b, i| {
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switch (b) {
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'A'...']' => out[i] = b + 0x20,
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else => out[i] = b,
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-
}
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switch (char) {
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'A'...']' => return char + 0x20,
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else => return char,
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}
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},
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}
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}
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+
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pub fn caseFold(a: []const u8, b: []const u8) bool {
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if (a.len != b.len) return false;
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var i: usize = 0;
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while (i < a.len) {
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const diff = std.mem.indexOfDiff(u8, a[i..], b[i..]) orelse return true;
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const a_diff = caseMap(a[diff], .rfc1459);
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const b_diff = caseMap(b[diff], .rfc1459);
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if (a_diff != b_diff) return false;
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i += diff + 1;
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}
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return true;
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}
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+
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test "caseFold" {
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try testing.expect(caseFold("a", "A"));
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try testing.expect(caseFold("aBcDeFgH", "abcdefgh"));
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+
}