private void readSubStreamsInfo()

in src/main/java/org/apache/commons/compress/archivers/sevenz/SevenZFile.java [1641:1718]
72 lines of code
20 McCabe index (conditional complexity)

    private void readSubStreamsInfo(final ByteBuffer header, final Archive archive) throws IOException {
        for (final Folder folder : archive.folders) {
            folder.numUnpackSubStreams = 1;
        }
        long unpackStreamsCount = archive.folders.length;

        int nid = getUnsignedByte(header);
        if (nid == NID.kNumUnpackStream) {
            unpackStreamsCount = 0;
            for (final Folder folder : archive.folders) {
                final long numStreams = readUint64(header);
                folder.numUnpackSubStreams = (int) numStreams;
                unpackStreamsCount += numStreams;
            }
            nid = getUnsignedByte(header);
        }

        final int totalUnpackStreams = (int) unpackStreamsCount;
        final SubStreamsInfo subStreamsInfo = new SubStreamsInfo(totalUnpackStreams);
        int nextUnpackStream = 0;
        for (final Folder folder : archive.folders) {
            if (folder.numUnpackSubStreams == 0) {
                continue;
            }
            long sum = 0;
            if (nid == NID.kSize) {
                for (int i = 0; i < folder.numUnpackSubStreams - 1; i++) {
                    final long size = readUint64(header);
                    subStreamsInfo.unpackSizes[nextUnpackStream++] = size;
                    sum += size;
                }
            }
            if (sum > folder.getUnpackSize()) {
                throw new IOException("sum of unpack sizes of folder exceeds total unpack size");
            }
            subStreamsInfo.unpackSizes[nextUnpackStream++] = folder.getUnpackSize() - sum;
        }
        if (nid == NID.kSize) {
            nid = getUnsignedByte(header);
        }

        int numDigests = 0;
        for (final Folder folder : archive.folders) {
            if (folder.numUnpackSubStreams != 1 || !folder.hasCrc) {
                numDigests += folder.numUnpackSubStreams;
            }
        }

        if (nid == NID.kCRC) {
            final BitSet hasMissingCrc = readAllOrBits(header, numDigests);
            final long[] missingCrcs = new long[numDigests];
            for (int i = 0; i < numDigests; i++) {
                if (hasMissingCrc.get(i)) {
                    missingCrcs[i] = 0xffffFFFFL & getInt(header);
                }
            }
            int nextCrc = 0;
            int nextMissingCrc = 0;
            for (final Folder folder : archive.folders) {
                if (folder.numUnpackSubStreams == 1 && folder.hasCrc) {
                    subStreamsInfo.hasCrc.set(nextCrc, true);
                    subStreamsInfo.crcs[nextCrc] = folder.crc;
                    ++nextCrc;
                } else {
                    for (int i = 0; i < folder.numUnpackSubStreams; i++) {
                        subStreamsInfo.hasCrc.set(nextCrc, hasMissingCrc.get(nextMissingCrc));
                        subStreamsInfo.crcs[nextCrc] = missingCrcs[nextMissingCrc];
                        ++nextCrc;
                        ++nextMissingCrc;
                    }
                }
            }

            nid = getUnsignedByte(header);
        }

        archive.subStreamsInfo = subStreamsInfo;
    }