move use of utf8DecodeWasm to utf8.ts

msgpack · May 16, 2019 · 6066940 · 6066940
1 parent 6c55452
commit 6066940
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Showing 2 changed files with 8 additions and 7 deletions.
diff --git a/src/Decoder.ts b/src/Decoder.ts
@@ -2,7 +2,6 @@ import { prettyByte } from "./utils/prettyByte";
 import { ExtensionCodec } from "./ExtensionCodec";
 import { getInt64, getUint64 } from "./utils/int";
 import { utf8Decode } from "./utils/utf8";
-import { utf8DecodeWasm, WASM_AVAILABLE } from "./wasmFunctions";
 import { createDataView, ensureUint8Array } from "./utils/typedArrays";
 
 enum State {
@@ -379,12 +378,7 @@ export class Decoder {
       throw MORE_DATA;
     }
 
-    let object: string;
-    if (WASM_AVAILABLE) {
-      object = utf8DecodeWasm(this.bytes, this.pos + headOffset, byteLength);
-    } else {
-      object = utf8Decode(this.bytes, this.pos + headOffset, byteLength);
-    }
+    const object = utf8Decode(this.bytes, this.pos + headOffset, byteLength);
     this.pos += headOffset + byteLength;
     return object;
   }

diff --git a/src/utils/utf8.ts b/src/utils/utf8.ts
@@ -1,4 +1,7 @@
 import { prettyByte } from "./prettyByte";
+import { WASM_AVAILABLE, utf8DecodeWasm } from "../wasmFunctions";
+
+const WASM_THRESHOLD = 0x100;
 
 export function utf8Count(str: string): number {
   const strLength = str.length;
@@ -86,6 +89,10 @@ export function utf8Encode(str: string, view: DataView, offset: number): void {
 }
 
 export function utf8Decode(bytes: Uint8Array, offset: number, byteLength: number): string {
+  if (WASM_AVAILABLE && byteLength > WASM_THRESHOLD) {
+    return utf8DecodeWasm(bytes, offset, byteLength);
+  }
+
   const out: Array<number> = [];
   const end = offset + byteLength;
   while (offset < end) {