public static boolean contentEquals()

in src/main/java/org/apache/commons/io/channels/FileChannels.java [61:101]
36 lines of code
11 McCabe index (conditional complexity)

    public static boolean contentEquals(final ReadableByteChannel channel1, final ReadableByteChannel channel2, final int bufferCapacity) throws IOException {
        // Before making any changes, please test with org.apache.commons.io.jmh.IOUtilsContentEqualsInputStreamsBenchmark
        // Short-circuit test
        if (Objects.equals(channel1, channel2)) {
            return true;
        }
        // Don't use ByteBuffer#compact() to avoid extra copying.
        final ByteBuffer c1Buffer = ByteBuffer.allocateDirect(bufferCapacity);
        final ByteBuffer c2Buffer = ByteBuffer.allocateDirect(bufferCapacity);
        int c1NumRead = 0;
        int c2NumRead = 0;
        boolean c1Read0 = false;
        boolean c2Read0 = false;
        // If a channel is a non-blocking channel, it may return 0 bytes read for any given call.
        while (true) {
            if (!c2Read0) {
                c1NumRead = readToLimit(channel1, c1Buffer);
                c1Buffer.clear();
                c1Read0 = c1NumRead == 0;
            }
            if (!c1Read0) {
                c2NumRead = readToLimit(channel2, c2Buffer);
                c2Buffer.clear();
                c2Read0 = c2NumRead == 0;
            }
            if (c1NumRead == IOUtils.EOF && c2NumRead == IOUtils.EOF) {
                return c1Buffer.equals(c2Buffer);
            }
            if (c1NumRead == 0 || c2NumRead == 0) {
                // 0 may be returned from a non-blocking channel.
                Thread.yield();
                continue;
            }
            if (c1NumRead != c2NumRead) {
                return false;
            }
            if (!c1Buffer.equals(c2Buffer)) {
                return false;
            }
        }
    }