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Diffstat (limited to 'src/SampleQueue.h')
-rw-r--r-- | src/SampleQueue.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/SampleQueue.h b/src/SampleQueue.h new file mode 100644 index 0000000..fddc3a4 --- /dev/null +++ b/src/SampleQueue.h @@ -0,0 +1,123 @@ +/* + Copyright (C) 2013, 2014 + Matthias P. Braendli, matthias.braendli@mpb.li + + An implementation for a threadsafe queue using boost thread library + for audio samples. +*/ + +#ifndef _SAMPLE_QUEUE_H_ +#define _SAMPLE_QUEUE_H_ + +#include <boost/thread.hpp> +#include <queue> + +/* This queue is meant to be used by two threads. One producer + * that pushes elements into the queue, and one consumer that + * retrieves the elements. + * + * The queue can make the consumer block until enough elements + * are available. + */ + +template<typename T> +class SampleQueue +{ +public: + SampleQueue(unsigned int bytes_per_sample, + unsigned int channels, + size_t max_size) : + m_bytes_per_sample(bytes_per_sample), + m_channels(channels), m_max_size(max_size) {} + + + /* Push a bunch of samples into the buffer */ + size_t push(const T *val, size_t len) + { + boost::mutex::scoped_lock lock(m_mutex); + + if (m_queue.size() >= m_max_size) { + return 0; + } + + for (size_t i = 0; i < len; i++) { + m_queue.push_back(val[i]); + } + + size_t new_size = m_queue.size(); + lock.unlock(); + + //m_condition_variable.notify_one(); + + return new_size; + } + + bool empty() const + { + boost::mutex::scoped_lock lock(m_mutex); + return m_queue.empty(); + } + + /* Get len elements, place them into the buf array + * Returns the number of elements it was able to take + * from the queue + */ + size_t pop(T* buf, size_t len) + { + boost::mutex::scoped_lock lock(m_mutex); + + size_t ret = 0; + + if (m_queue.size() < len) { + size_t i; + for (i = 0; i < m_queue.size(); i++) { + buf[i] = m_queue[i]; + } + + ret = i; + + for (; i < len; i++) { + buf[i] = 0; + } + + m_queue.resize(0); + } + else { + for (size_t i = 0; i < len; i++) { + buf[i] = m_queue[i]; + } + + ret = len; + + m_queue.erase(m_queue.front(), m_queue.front() + len); + } + + return ret; + } + + /* + void wait_and_pop(T& popped_value) + { + boost::mutex::scoped_lock lock(m_mutex); + while(m_queue.size() < m_required_size) + { + m_condition_variable.wait(lock); + } + + popped_value = m_queue.front(); + m_queue.pop_front(); + } + */ + +private: + std::deque<T> m_queue; + mutable boost::mutex m_mutex; + //boost::condition_variable m_condition_variable; + + unsigned int m_channels; + unsigned int m_bytes_per_sample; + size_t m_max_size; +}; + +#endif + |