Class StatusMessageMarshaller

api/src/main/java/io/grpc/Status.java:572–651

  }

  private static final class StatusMessageMarshaller implements TrustedAsciiMarshaller<String> {

    private static final byte[] HEX =
        {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

    @Override
    public byte[] toAsciiString(String value) {
      byte[] valueBytes = value.getBytes(UTF_8);
      for (int i = 0; i < valueBytes.length; i++) {
        byte b = valueBytes[i];
        // If there are only non escaping characters, skip the slow path.
        if (isEscapingChar(b)) {
          return toAsciiStringSlow(valueBytes, i);
        }
      }
      return valueBytes;
    }

    private static boolean isEscapingChar(byte b) {
      return b < ' ' || b >= '~' || b == '%';
    }

    /**
     * Percent encode bytes to make them ASCII.
     *
     * @param valueBytes the UTF-8 bytes
     * @param ri The reader index, pointed at the first byte that needs escaping.
     */
    private static byte[] toAsciiStringSlow(byte[] valueBytes, int ri) {
      byte[] escapedBytes = new byte[ri + (valueBytes.length - ri) * 3];
      // copy over the good bytes
      if (ri != 0) {
        System.arraycopy(valueBytes, 0, escapedBytes, 0, ri);
      }
      int wi = ri;
      for (; ri < valueBytes.length; ri++) {
        byte b = valueBytes[ri];
        // Manually implement URL encoding, per the gRPC spec.
        if (isEscapingChar(b)) {
          escapedBytes[wi] = '%';
          escapedBytes[wi + 1] = HEX[(b >> 4) & 0xF];
          escapedBytes[wi + 2] = HEX[b & 0xF];
          wi += 3;
          continue;
        }
        escapedBytes[wi++] = b;
      }
      return Arrays.copyOf(escapedBytes, wi);
    }

    @SuppressWarnings("deprecation") // Use fast but deprecated String ctor
    @Override
    public String parseAsciiString(byte[] value) {
      for (int i = 0; i < value.length; i++) {
        byte b = value[i];
        if (b < ' ' || b >= '~' || (b == '%' && i + 2 < value.length)) {
          return parseAsciiStringSlow(value);
        }