private void move(int length) {
        if (length > 0) {
            // Move our location to aid error reporting.
            for (int i = 0; i < length; i++) {
                if (inBuffer.charAt(i) == '\n') {
                    lineNo++;
                    colNo = 0;
                } else {
                    colNo++;
                }
            }

            inBuffer.move(length);
        }
    }
Read text into the input buffer, replace the first match if possible and copy replaced text to the output buffer.
stroom-pipeline/src/main/java/stroom/pipeline/reader/FindReplaceFilter.java