Js5Util.java

protected byte[] unpackMetadata(byte[] data) {
        Buffer buffer = new Buffer(data);
        int compression = buffer.g1();
        int inSize = buffer.g4();

        switch (compression) {
            case 0: { //No compression
                final byte[] output = new byte[inSize];
                buffer.gdata(output, 0, inSize);
                return output;
            }
            case 1: { //BZIP2 Compression
                int outSize = buffer.g4();
                byte[] output = new byte[outSize];
                BZ2InputStream.decompress(output, outSize, data, 9);
                return output;
            }
            case 2: { //GZIP Compression
                int outSize = buffer.g4();
                byte[] output = new byte[outSize];
                new GZipDeflater().deflate(buffer, output);
                return output;
            }
            default:
                throw new RuntimeException("Unknown Compression Type: " + compression);
        }
    }

protected void decodeMetadata(byte[] packed) {
        final Buffer buffer = new Buffer(unpackMetadata(packed));
        final int protocol = buffer.g1();

        if (protocol < 5 || protocol > 7)
            throw new RuntimeException("Incorrect JS5 protocol number: ");

        if (protocol >= 6) {
            int indexVersion = buffer.g4();
        }

        final int identifierFlag = buffer.g1();
        if (protocol >= 7) {
            this.entryCount = buffer.gsmarti();
        } else {
            this.entryCount = buffer.g2();
        }


        int offset = 0;
        int largestGroupID = -1;
        this.entry_group_id = new int[this.entryCount];
        if (protocol >= 7) {
            for (int e = 0; e < (this.entryCount); e++) {
                this.entry_group_id[e] = offset += buffer.gsmarti();
                if (this.entry_group_id[e] > largestGroupID) {
                    largestGroupID = this.entry_group_id[e];
                }
            }
        } else {
            for (int i_5_ = 0; i_5_ < (this.entryCount); i_5_++) {
                this.entry_group_id[i_5_] = offset += buffer.g2();
                if (this.entry_group_id[i_5_] > largestGroupID) {
                    largestGroupID = this.entry_group_id[i_5_];
                }
            }
        }
        this.file_crc_values = new int[largestGroupID + 1];
        this.file_version_values = new int[largestGroupID + 1];
        this.file_counts = new int[largestGroupID + 1];
        this.file_cache_indices = new int[largestGroupID + 1][];
        this.group_data_buffers = new Object[largestGroupID + 1];
        this.file_data_buffers = new Object[largestGroupID + 1][];

        if (identifierFlag != 0) {
            this.group_name_hashes = new int[largestGroupID + 1];
            for (int i_6_ = 0; i_6_ < (this.entryCount); i_6_++) {
                this.group_name_hashes[(this.entry_group_id[i_6_])] = buffer.g4();
            }
            this.nameHashTable = new NameHashTable(this.group_name_hashes);
        }
        for (int crc = 0; crc < (this.entryCount); crc++) {
            this.file_crc_values[(this.entry_group_id[crc])] = buffer.g4();
        }
        for (int version = 0; version < (this.entryCount); version++) {
            this.file_version_values[(this.entry_group_id[version])] = buffer.g4();
        }
        for (int child = 0; child < (this.entryCount); child++) {
            this.file_counts[(this.entry_group_id[child])] = buffer.g2();
        }
        if (protocol >= 7) {
            for (int entry = 0; entry < (this.entryCount); entry++) {
                final int index = this.entry_group_id[entry];
                final int children = this.file_counts[index];
                offset = 0;
                int length = -1;
                this.file_cache_indices[index] = new int[children];
                for (int child = 0; child < children; child++) {
                    final int size = (this.file_cache_indices[index][child] = offset += buffer.gsmarti());
                    if (size > length) {
                        length = size;
                    }
                }
                this.file_data_buffers[index] = new Object[length + 1];
            }
        } else {
            for (int i_16_ = 0; i_16_ < (this.entryCount); i_16_++) {
                final int index = this.entry_group_id[i_16_];
                final int children = this.file_counts[index];
                offset = 0;
                int i_19_ = -1;
                this.file_cache_indices[index] = new int[children];
                for (int i_20_ = 0; i_20_ < children; i_20_++) {
                    final int i_21_ = (this.file_cache_indices[index][i_20_] = offset += buffer.g2());
                    if (i_21_ > i_19_) {
                        i_19_ = i_21_;
                    }
                }
                this.file_data_buffers[index] = new Object[1 + i_19_];
            }
        }
        if (identifierFlag != 0) {
            this.group_child_names_raw = new int[largestGroupID + 1][];
            this.group_file_names = new NameHashTable[largestGroupID + 1];
            for (int entry = 0; entry < (this.entryCount); entry++) {
                final int groupId = this.entry_group_id[entry];
                final int entryCount = this.file_counts[groupId];
                this.group_child_names_raw[groupId] = (new int[this.file_data_buffers[groupId].length]);
                for (int fileEntry = 0; fileEntry < entryCount; fileEntry++) {
                    this.group_child_names_raw[groupId][this.file_cache_indices[groupId][fileEntry]] = buffer.g4();
                }
                this.group_file_names[groupId] = new NameHashTable(this.group_child_names_raw[groupId]);
            }
        }

    }