std::unique_ptr get_istream_for_file()

in source/neuropod/internal/neuropod_loader.cc [116:163]

• 35 lines of code
• 6 McCabe index (conditional complexity)

    std::unique_ptr<std::istream> get_istream_for_file(const std::string &path) override
    {
        auto out = stdx::make_unique<std::stringstream>();

        // Find the file we're looking for
        auto err = mz_zip_reader_locate_entry(zip_reader_, path.c_str(), 1);
        if (err != MZ_OK)
        {
            SPDLOG_TRACE("Couldn't find file in zip: {}", path);
            return nullptr;
        }

        // Open it
        err = mz_zip_reader_entry_open(zip_reader_);
        if (err != MZ_OK)
        {
            SPDLOG_TRACE("Couldn't open file '{}' in zip file: {}", path, err);
            return nullptr;
        }

        char    buf[4096];
        int32_t bytes_read = 0;

        do
        {
            // Read chunks and write to the output stream
            bytes_read = mz_zip_reader_entry_read(zip_reader_, buf, sizeof(buf));
            if (bytes_read < 0)
            {
                err = bytes_read;
                break;
            }

            out->write(buf, bytes_read);
        } while (bytes_read > 0);

        // Close the reader
        mz_zip_reader_entry_close(zip_reader_);

        // Make sure we correctly read the file
        if (err != MZ_OK)
        {
            SPDLOG_TRACE("Error reading zip file entry: {}", err);
            return nullptr;
        }

        return out;
    }