private long readLines()

in src/main/java/org/apache/commons/io/input/Tailer.java [895:938]
41 lines of code
9 McCabe index (conditional complexity)

    private long readLines(final RandomAccessResourceBridge reader) throws IOException {
        try (ByteArrayOutputStream lineBuf = new ByteArrayOutputStream(64)) {
            long pos = reader.getPointer();
            long rePos = pos; // position to re-read
            int num;
            boolean seenCR = false;
            while (getRun() && (num = reader.read(inbuf)) != EOF) {
                for (int i = 0; i < num; i++) {
                    final byte ch = inbuf[i];
                    switch (ch) {
                    case LF:
                        seenCR = false; // swallow CR before LF
                        listener.handle(new String(lineBuf.toByteArray(), charset));
                        lineBuf.reset();
                        rePos = pos + i + 1;
                        break;
                    case CR:
                        if (seenCR) {
                            lineBuf.write(CR);
                        }
                        seenCR = true;
                        break;
                    default:
                        if (seenCR) {
                            seenCR = false; // swallow final CR
                            listener.handle(new String(lineBuf.toByteArray(), charset));
                            lineBuf.reset();
                            rePos = pos + i + 1;
                        }
                        lineBuf.write(ch);
                    }
                }
                pos = reader.getPointer();
            }

            reader.seek(rePos); // Ensure we can re-read if necessary

            if (listener instanceof TailerListenerAdapter) {
                ((TailerListenerAdapter) listener).endOfFileReached();
            }

            return rePos;
        }
    }