Review

finding-10

/mubench/checkouts/closure/319/build/src/com/google/javascript/jscomp/SourceFile.java

getLine(int)

class SourceFile {
  /**
   * Gets the source line for the indicated line number.
   *
   * @param lineNumber the line number, 1 being the first line of the file.
   * @return The line indicated. Does not include the newline at the end
   *     of the file. Returns {@code null} if it does not exist,
   *     or if there was an IO exception.
   */
  public String getLine(int lineNumber) {
    String js = "";
    try {
      // NOTE(nicksantos): Right now, this is optimized for few warnings.
      // This is probably the right trade-off, but will be slow if there
      // are lots of warnings in one file.
      js = getCode();
    } catch (IOException e) {
      return null;
    }

    int pos = 0;
    int startLine = 1;

    // If we've saved a previous offset and it's for a line less than the
    // one we're searching for, then start at that point.
    if (lineNumber >= lastLine) {
      pos = lastOffset;
      startLine = lastLine;
    }

    for (int n = startLine; n < lineNumber; n++) {
      int nextpos = js.indexOf('\n', pos);
      if (nextpos == -1) {
        return null;
      }
      pos = nextpos + 1;
    }

    // Remember this offset for the next search we do.
    lastOffset = pos;
    lastLine = lineNumber;

    return (js.indexOf('\n', pos) == -1) ? null :
        js.substring(pos, js.indexOf('\n', pos));
  }

}