Make `buffer.toString("base64")` 4x faster (#3486)

* Add libbase64

* Add bench

* Update licensing.md

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

3 files changed, 21 insertions, 3 deletions

diff --git a/src/base64/base64.zig b/src/base64/base64.zig
index bddc44564..8768b9c7b 100644
--- a/src/base64/base64.zig
+++ b/src/base64/base64.zig
@@ -5,6 +5,22 @@ pub const DecodeResult = struct {
     fail: bool = false,
 };
 
+pub const LibBase64 = struct {
+    pub const State = extern struct {
+        eof: c_int,
+        bytes: c_int,
+        flags: c_int,
+        carry: u8,
+    };
+    pub extern fn base64_encode(src: [*]const u8, srclen: usize, out: [*]u8, outlen: *usize, flags: c_int) void;
+    pub extern fn base64_stream_encode_init(state: *State, flags: c_int) void;
+    pub extern fn base64_stream_encode(state: *State, src: [*]const u8, srclen: usize, out: [*]u8, outlen: *usize) void;
+    pub extern fn base64_stream_encode_final(state: *State, out: [*]u8, outlen: *usize) void;
+    pub extern fn base64_decode(src: [*]const u8, srclen: usize, out: [*]u8, outlen: *usize, flags: c_int) c_int;
+    pub extern fn base64_stream_decode_init(state: *State, flags: c_int) void;
+    pub extern fn base64_stream_decode(state: *State, src: [*]const u8, srclen: usize, out: [*]u8, outlen: *usize) c_int;
+};
+
 const mixed_decoder = brk: {
     var decoder = zig_base64.standard.decoderWithIgnore("\xff \t\r\n" ++ [_]u8{
         std.ascii.control_code.vt,
@@ -30,7 +46,9 @@ pub fn decode(destination: []u8, source: []const u8) DecodeResult {
 }
 
 pub fn encode(destination: []u8, source: []const u8) usize {
-    return zig_base64.standard.Encoder.encode(destination, source).len;
+    var outlen: usize = destination.len;
+    LibBase64.base64_encode(source.ptr, source.len, destination.ptr, &outlen, 0);
+    return outlen;
 }
 
 pub fn decodeLenUpperBound(len: usize) usize {
diff --git a/src/bun.js/node/types.zig b/src/bun.js/node/types.zig
index b01eca8e0..96d04636e 100644
--- a/src/bun.js/node/types.zig
+++ b/src/bun.js/node/types.zig
@@ -524,8 +524,8 @@ pub const Encoding = enum(u8) {
         switch (encoding) {
             .base64 => {
                 var base64: [std.base64.standard.Encoder.calcSize(size)]u8 = undefined;
-                const result = JSC.ZigString.init(std.base64.standard.Encoder.encode(&base64, input)).toValueGC(globalThis);
-                return result;
+                const len = bun.base64.encode(&base64, input);
+                return JSC.ZigString.init(base64[0..len]).toValueGC(globalThis);
             },
             .base64url => {
                 var buf: [std.base64.url_safe.Encoder.calcSize(size) + "data:;base64,".len]u8 = undefined;
diff --git a/src/deps/base64 b/src/deps/base64
new file mode 160000
+Subproject e77bd70bdd860c52c561568cffb251d88bba064