Function UTF8ArrayToString

frontend/js/lib/decoder.js:263–298

(heapOrArray, idx, maxBytesToRead)

	  }
	  var UTF8Decoder = typeof TextDecoder != "undefined" ? new TextDecoder("utf8") : undefined;
	  function UTF8ArrayToString(heapOrArray, idx, maxBytesToRead) {
	    var endIdx = idx + maxBytesToRead;
	    var endPtr = idx;
	    while (heapOrArray[endPtr] && !(endPtr >= endIdx)) ++endPtr;
	    if (endPtr - idx > 16 && heapOrArray.buffer && UTF8Decoder) {
	      return UTF8Decoder.decode(heapOrArray.subarray(idx, endPtr));
	    } else {
	      var str = "";
	      while (idx < endPtr) {
	        var u0 = heapOrArray[idx++];
	        if (!(u0 & 128)) {
	          str += String.fromCharCode(u0);
	          continue;
	        }
	        var u1 = heapOrArray[idx++] & 63;
	        if ((u0 & 224) == 192) {
	          str += String.fromCharCode((u0 & 31) << 6 | u1);
	          continue;
	        }
	        var u2 = heapOrArray[idx++] & 63;
	        if ((u0 & 240) == 224) {
	          u0 = (u0 & 15) << 12 | u1 << 6 | u2;
	        } else {
	          if ((u0 & 248) != 240) warnOnce("Invalid UTF-8 leading byte 0x" + u0.toString(16) + " encountered when deserializing a UTF-8 string in wasm memory to a JS string!");
	          u0 = (u0 & 7) << 18 | u1 << 12 | u2 << 6 | heapOrArray[idx++] & 63;
	        }
	        if (u0 < 65536) {
	          str += String.fromCharCode(u0);
	        } else {
	          var ch = u0 - 65536;
	          str += String.fromCharCode(55296 | ch >> 10, 56320 | ch & 1023);
	        }
	      }
	    }
	    return str;
	  }
	  function UTF8ToString(ptr, maxBytesToRead) {
	    return ptr ? UTF8ArrayToString(HEAPU8, ptr, maxBytesToRead) : "";
	  }