/* ----------------------------------------------------------------------- *//**
 *
 * @file OutputStreamBufferBase_impl.hpp
 *
 *//* ----------------------------------------------------------------------- */

// Workaround for Doxygen: Ignore if not included by EigenLinAlgTypes.hpp
#ifdef MADLIB_DBAL_HPP

/**
 * @internal One extra byte is allocated for the terminating null character.
 */
template <class Derived, typename C>
OutputStreamBufferBase<Derived, C>::OutputStreamBufferBase()
:   mStorageSize(kInitialBufferSize),
    mStorage(new C[kInitialBufferSize + 1]) {
    
    setp(mStorage, mStorage + mStorageSize);
}

template <class Derived, typename C>
OutputStreamBufferBase<Derived, C>::~OutputStreamBufferBase() {
    delete mStorage;
}

/**
 * @brief Output a string
 *
 * Subclasses are required to implement this method and to feed the message
 * the the the DBMS-specific logging routine.
 * @param inMsg Null-terminated string to be output.
 * @param inLength Length of inMsg (for convenience).
 */
template <class Derived, typename C>
void
OutputStreamBufferBase<Derived, C>::output(C* inMsg, uint32_t inLength) const {
    static_cast<const Derived*>(this)->output(inMsg, inLength);
}

/**
 * @brief Handle case when stream receives a character that does not fit
 *        into the current buffer any more
 *
 * This function will allocate a new buffer of twice the old buffer size. If
 * the buffer has already the maximum size kMaxBufferSize, eof is returned
 * to indicate that the buffer cannot take any more input before a flush.
 */
template <class Derived, typename C>
typename OutputStreamBufferBase<Derived, C>::int_type
OutputStreamBufferBase<Derived, C>::overflow(int_type c) {
    if (this->pptr() >= this->epptr()) {
        if (mStorageSize >= kMaxBufferSize)
            return traits_type::eof();
        
        uint32_t newStorageSize = mStorageSize * 2;
        C* newStorage = new C[newStorageSize + 1];
        std::memcpy(newStorage, mStorage, mStorageSize);
        delete mStorage;
        mStorage = newStorage;
        
        madlib_assert(
            this->pptr() == this->epptr() &&
            this->pptr() - this->pbase() == static_cast<int64_t>(mStorageSize),
            std::logic_error("Internal error: Logging buffer has become "
                "inconsistent"));
        
        setp(mStorage, mStorage + newStorageSize);
        this->pbump(mStorageSize);
        mStorageSize = newStorageSize;
    } else if (c == traits_type::eof())
       return traits_type::eof();

    *this->pptr() = c;
    this->pbump(1);
    return traits_type::not_eof(c);
}

/**
 * @brief Flush and reset buffer.
 */
template <class Derived, typename C>
int
OutputStreamBufferBase<Derived, C>::sync() {
    int length = this->pptr() - this->pbase();
    
    mStorage[length] = '\0';
    output(mStorage, length);

    setp(mStorage, mStorage + mStorageSize);
    return 0;
}

#endif // MADLIB_DBAL_HPP (workaround for Doxygen)