Decompressing large files such as 5.9GB, the decompression speed is gradually abnormally slow

[XuXin007]

Decompressing large files such as 5.9GB, the decompression speed is gradually abnormally slow

[omicronapps]

The decompression speed of 7-Zip-JBinding-4Android is directly dependent to the implementations of the underlying 7-Zip-JBinding and 7-Zip libraries.

However, you would want to ensure that you are using IInArchive.extract() rather than IInArchive.extractSlow(). Also, you may want to consider extracting in-memory, to the extent possible. As an example, something like the following.

    void extract(File file) {
        try {
            RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r");
            RandomAccessFileInStream inStream = new RandomAccessFileInStream(randomAccessFile);
            IInArchive inArchive = SevenZip.openInArchive(null, inStream);
            List<MyData> data = new ArrayList<>();
            ArchiveExtractCallback extractCallback = new ArchiveExtractCallback(data);
            inArchive.extract(null, false, extractCallback);
        } catch (SevenZipException e) {
        }
    }

    private class ArchiveExtractCallback implements IArchiveExtractCallback {
        private List<MyData> mData;

        ArchiveExtractCallback(IInArchive inArchive, List<MyData> data) {
            mData = data;
        }

        @Override
        public ISequentialOutStream getStream(int index, ExtractAskMode extractAskMode) throws SevenZipException {
            SequentialOutStream stream = new SequentialOutStream(mData);
            return stream;
        }

        @Override
        public void prepareOperation(ExtractAskMode extractAskMode) throws SevenZipException {
        }

        @Override
        public void setOperationResult(ExtractOperationResult extractOperationResult) throws SevenZipException {
            if (extractOperationResult != ExtractOperationResult.OK) {
                throw new SevenZipException(extractOperationResult.toString());
            }
        }

        @Override
        public void setTotal(long total) throws SevenZipException {
        }

        @Override
        public void setCompleted(long complete) throws SevenZipException {
        }
    }

    private class SequentialOutStream implements ISequentialOutStream {
        private List<MyData> mData;

        SequentialOutStream(List<MyData> data) {
            mData = data;
        }

        @Override
        public int write(byte[] data) throws SevenZipException {
            if (data == null) {
                throw new SevenZipException("null data");
            }
            mData.add(data);
            return data.length;
        }
    }