refactor(web): use encoding_rs for text encoding (#10844)

This commit removes all JS based text encoding / text decoding. Instead
encoding now happens in Rust via encoding_rs (already in tree). This
implementation retains stream support, but adds the last missing
encodings. We are incredibly close to 100% WPT on text encoding now.

This should reduce our baseline heap by quite a bit.

2 files changed, 6 insertions, 8 deletions

diff --git a/extensions/file/01_file.js b/extensions/file/01_file.js
index c34561b5e..c9c66127f 100644
--- a/extensions/file/01_file.js
+++ b/extensions/file/01_file.js
@@ -12,6 +12,7 @@
 "use strict";
 
 ((window) => {
+  const core = window.Deno.core;
   const webidl = window.__bootstrap.webidl;
 
   // TODO(lucacasonato): this needs to not be hardcoded and instead depend on
@@ -85,9 +86,6 @@
     return finalBytes;
   }
 
-  const utf8Encoder = new TextEncoder();
-  const utf8Decoder = new TextDecoder();
-
   /** @typedef {BufferSource | Blob | string} BlobPart */
 
   /**
@@ -116,7 +114,7 @@
         if (endings == "native") {
           s = convertLineEndingsToNative(s);
         }
-        bytesArrays.push(utf8Encoder.encode(s));
+        bytesArrays.push(core.encode(s));
       } else {
         throw new TypeError("Unreachable code (invalild element type)");
       }
@@ -276,7 +274,7 @@
     async text() {
       webidl.assertBranded(this, Blob);
       const buffer = await this.arrayBuffer();
-      return utf8Decoder.decode(buffer);
+      return core.decode(new Uint8Array(buffer));
     }
 
     /**
diff --git a/extensions/file/02_filereader.js b/extensions/file/02_filereader.js
index 428d8fd54..c7ca3d980 100644
--- a/extensions/file/02_filereader.js
+++ b/extensions/file/02_filereader.js
@@ -14,9 +14,9 @@
 
 ((window) => {
   const webidl = window.__bootstrap.webidl;
-  const { decode } = window.__bootstrap.encoding;
+  const { forgivingBase64Encode } = window.__bootstrap.infra;
+  const { decode, TextDecoder } = window.__bootstrap.encoding;
   const { parseMimeType } = window.__bootstrap.mimesniff;
-  const base64 = window.__bootstrap.base64;
 
   const state = Symbol("[[state]]");
   const result = Symbol("[[result]]");
@@ -168,7 +168,7 @@
                   case "DataUrl": {
                     const mediaType = blob.type || "application/octet-stream";
                     this[result] = `data:${mediaType};base64,${
-                      base64.fromByteArray(bytes)
+                      forgivingBase64Encode(bytes)
                     }`;
                     break;
                   }