size_t
RingBufferPool::getData(AudioBuffer& buffer, const std::string& call_id)
{
    std::lock_guard<std::recursive_mutex> lk(stateLock_);

    const auto bindings = getReadBindings(call_id);
    if (not bindings)
        return 0;

    // No mixing
    if (bindings->size() == 1)
        return (*bindings->cbegin())->get(buffer, call_id);

    buffer.reset();
    buffer.setFormat(internalAudioFormat_);

    size_t size = 0;
    AudioBuffer mixBuffer(buffer);

    for (const auto& rbuf : *bindings) {
        // XXX: is it normal to only return the last positive size?
        size = rbuf->get(mixBuffer, call_id);
        if (size > 0)
            buffer.mix(mixBuffer);
    }

    return size;
}
size_t
RingBufferPool::getAvailableData(AudioBuffer& buffer, const std::string& call_id)
{
    std::lock_guard<std::recursive_mutex> lk(stateLock_);

    auto bindings = getReadBindings(call_id);
    if (not bindings)
        return 0;

    // No mixing
    if (bindings->size() == 1) {
        return (*bindings->cbegin())->get(buffer, call_id);
    }

    size_t availableSamples = std::numeric_limits<size_t>::max();

    for (const auto& rbuf : *bindings)
        availableSamples = std::min(availableSamples,
                                    rbuf->availableForGet(call_id));

    if (availableSamples == std::numeric_limits<size_t>::max())
        return 0;

    availableSamples = std::min(availableSamples, buffer.frames());

    buffer.resize(availableSamples);
    buffer.reset();
    buffer.setFormat(internalAudioFormat_);

    AudioBuffer mixBuffer(buffer);

    for (const auto &rbuf : *bindings) {
        if (rbuf->get(mixBuffer, call_id) > 0)
            buffer.mix(mixBuffer);
    }

    return availableSamples;
}