DataReader::DataReader(const LayerParameter& param, bool is_cpm_data)
: queue_pair_(new QueuePair(is_cpm_data ? //
param.cpmdata_param().prefetch() * param.cpmdata_param().batch_size() :
param.data_param().prefetch() * param.data_param().batch_size())) {
// Get or create a body
boost::mutex::scoped_lock lock(bodies_mutex_);
string key = source_key(param, is_cpm_data);
weak_ptr<Body>& weak = bodies_[key];
body_ = weak.lock();
if (!body_) {
body_.reset(new Body(param, is_cpm_data));
bodies_[key] = weak_ptr<Body>(body_);
}
body_->new_queue_pairs_.push(queue_pair_);
}
// A source is uniquely identified by its layer name + path, in case
// the same database is read from two different locations in the net.
static inline string source_key(const LayerParameter& param, bool is_cpm_data_) {
return param.name() + ":" + (is_cpm_data_ ? param.cpmdata_param().source() : param.data_param().source());
}