Method ReadRegistryStringValue

PathCopyCopy/src/PluginUtils.cpp:413–441

Reads the content of a string registry value and returns it in a std::wstring so that it's easier to manage. Will take care of reallocating buffers as needed. @param p_Key Key containing the value to read. @param p_pValueName Name of value. @param p_rValue Upon exit, will contain the value. @return Error code, or ERROR_SUCCESS if all goes well.

    // @return Error code, or ERROR_SUCCESS if all goes well.
    //
    long PluginUtils::ReadRegistryStringValue(const RegKey& p_Key,
                                              const wchar_t* const p_pValueName,
                                              std::wstring& p_rValue)
    {
        // Clear the content to assume value doesn't exist.
        p_rValue.clear();

        // Loop until we are able to read the value.
        long lRes = ERROR_MORE_DATA;
        ULONG curSize = 0;
        while (lRes == ERROR_MORE_DATA) {
            curSize += REG_BUFFER_CHUNK_SIZE;
            std::vector<wchar_t> vBuffer(curSize, L'\0');
            DWORD valueType = REG_SZ;
            DWORD curSizeInBytes = curSize * sizeof(wchar_t);
            lRes = p_Key.QueryValue(p_pValueName, &valueType, vBuffer.data(), &curSizeInBytes);
            if (lRes == ERROR_SUCCESS) {
                // Make sure it is a string.
                if (valueType == REG_SZ && (curSizeInBytes % sizeof(wchar_t)) == 0) {
                    // Success, copy resulting string.
                    p_rValue.assign(vBuffer.data());
                } else {
                    lRes = ERROR_INVALID_DATATYPE;
                }
            }
        }

        return lRes;
    }

    //
    // Given a multi-line string read from a REG_MULTI_SZ registry value,