private static FrameHeader readFrameHeader()

in java/src/main/java/com/epam/deltix/zstd/ZstdFrameDecompressor.java [843:920]
66 lines of code
14 McCabe index (conditional complexity)

    private static FrameHeader readFrameHeader(final ByteBuffer inputBase, final int inputAddress, final int inputLimit) {
        int input = inputAddress;
        verify(input < inputLimit, input, "Not enough input bytes");

        final int frameHeaderDescriptor = inputBase.get(input++) & 0xFF;
        final boolean singleSegment = (frameHeaderDescriptor & 0b100000) != 0;
        final int dictionaryDescriptor = frameHeaderDescriptor & 0b11;
        final int contentSizeDescriptor = frameHeaderDescriptor >>> 6;

        final int headerSize = 1 +
                (singleSegment ? 0 : 1) +
                (dictionaryDescriptor == 0 ? 0 : (1 << (dictionaryDescriptor - 1))) +
                (contentSizeDescriptor == 0 ? (singleSegment ? 1 : 0) : (1 << contentSizeDescriptor));

        verify(headerSize <= inputLimit - inputAddress, input, "Not enough input bytes");

        // decode window size
        int windowSize = -1;
        if (!singleSegment) {
            final int windowDescriptor = inputBase.get(input++) & 0xFF;
            final int exponent = windowDescriptor >>> 3;
            final int mantissa = windowDescriptor & 0b111;

            final int base = 1 << (MIN_WINDOW_LOG + exponent);
            windowSize = base + (base / 8) * mantissa;
        }

        // decode dictionary id
        long dictionaryId = -1;
        switch (dictionaryDescriptor) {
            case 1:
                dictionaryId = inputBase.get(input) & 0xFF;
                input += SIZE_OF_BYTE;
                break;
            case 2:
                dictionaryId = inputBase.getShort(input) & 0xFFFF;
                input += SIZE_OF_SHORT;
                break;
            case 3:
                dictionaryId = inputBase.getInt(input) & 0xFFFF_FFFFL;
                input += SIZE_OF_INT;
                break;
        }
        verify(dictionaryId == -1, input, "Custom dictionaries not supported");

        // decode content size
        long contentSize = -1;
        switch (contentSizeDescriptor) {
            case 0:
                if (singleSegment) {
                    contentSize = inputBase.get(input) & 0xFF;
                    input += SIZE_OF_BYTE;
                }
                break;
            case 1:
                contentSize = inputBase.getShort(input) & 0xFFFF;
                contentSize += 256;
                input += SIZE_OF_SHORT;
                break;
            case 2:
                contentSize = inputBase.getInt(input) & 0xFFFF_FFFFL;
                input += SIZE_OF_INT;
                break;
            case 3:
                contentSize = inputBase.getLong(input);
                input += SIZE_OF_LONG;
                break;
        }

        final boolean hasChecksum = (frameHeaderDescriptor & 0b100) != 0;

        return new FrameHeader(
                input - inputAddress,
                windowSize,
                contentSize,
                dictionaryId,
                hasChecksum);
    }