private int fillBuf()

in src/main/java/org/apache/commons/io/input/UnsynchronizedBufferedReader.java [141:178]

• 30 lines of code
• 9 McCabe index (conditional complexity)

    private int fillBuf() throws IOException {
        // assert(pos == end);

        if (mark == EOF || pos - mark >= markLimit) {
            /* mark isn't set or has exceeded its limit. use the whole buffer */
            final int result = in.read(buf, 0, buf.length);
            if (result > 0) {
                mark = -1;
                pos = 0;
                end = result;
            }
            return result;
        }

        if (mark == 0 && markLimit > buf.length) {
            /* the only way to make room when mark=0 is by growing the buffer */
            int newLength = buf.length * 2;
            if (newLength > markLimit) {
                newLength = markLimit;
            }
            final char[] newbuf = new char[newLength];
            System.arraycopy(buf, 0, newbuf, 0, buf.length);
            buf = newbuf;
        } else if (mark > 0) {
            /* make room by shifting the buffered data to left mark positions */
            System.arraycopy(buf, mark, buf, 0, buf.length - mark);
            pos -= mark;
            end -= mark;
            mark = 0;
        }

        /* Set the new position and mark position */
        final int count = in.read(buf, pos, buf.length - pos);
        if (count != EOF) {
            end += count;
        }
        return count;
    }