public void onNext()

in src/main/java/software/amazon/encryption/s3/internal/BufferedCipherSubscriber.java [63:98]
19 lines of code
6 McCabe index (conditional complexity)

    public void onNext(ByteBuffer byteBuffer) {
        int amountToReadFromByteBuffer = getAmountToReadFromByteBuffer(byteBuffer);

        if (amountToReadFromByteBuffer > 0) {
            byte[] buf = BinaryUtils.copyBytesFrom(byteBuffer, amountToReadFromByteBuffer);
            try {
                outputBuffer = cipher.update(buf, 0, amountToReadFromByteBuffer);
            } catch (final IllegalStateException exception) {
                // This happens when the stream is reset and the cipher is reused with the
                // same key/IV. It's actually fine here, because the data is the same, but any
                // sane implementation will throw an exception.
                // Request a new cipher using the same materials to avoid reinit issues
                cipher = CipherProvider.createAndInitCipher(materials, iv);
            }

            if (outputBuffer == null && amountToReadFromByteBuffer < cipher.getBlockSize()) {
                // The underlying data is too short to fill in the block cipher
                // This is true at the end of the file, so complete to get the final
                // bytes
                this.onComplete();
            }

            // Enqueue the buffer until all data is read
            buffers.add(ByteBuffer.wrap(outputBuffer));

            // Sometimes, onComplete won't be called, so we check if all
            // data is read to avoid hanging indefinitely
            if (contentRead.get() == contentLength) {
                this.onComplete();
            }
            // This avoids the subscriber waiting indefinitely for more data
            // without actually releasing any plaintext before it can be authenticated
            wrappedSubscriber.onNext(ByteBuffer.allocate(0));
        }

    }