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Diffstat (limited to 'raul/RingBuffer.h')
| -rw-r--r-- | raul/RingBuffer.h | 163 |
1 files changed, 0 insertions, 163 deletions
diff --git a/raul/RingBuffer.h b/raul/RingBuffer.h deleted file mode 100644 index beaf957..0000000 --- a/raul/RingBuffer.h +++ /dev/null @@ -1,163 +0,0 @@ -/* This file is part of Raul. - * Copyright (C) 2007 Dave Robillard <http://drobilla.net> - * - * Raul is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License as published by the Free Software - * Foundation; either version 2 of the License, or (at your option) any later - * version. - * - * Raul is distributed in the hope that it will be useful, but WITHOUT ANY - * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS - * FOR A PARTICULAR PURPOSE. See the GNU General Public License for details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - */ - -#ifndef RAUL__RING_BUFFER_H -#define RAUL__RING_BUFFER_H - -#include <cassert> -#include <glib.h> - -namespace Raul { - - -/** A lock-free RingBuffer. - * Read/Write realtime safe. - * Single-reader Single-writer thread safe. - */ -template <typename T> -class RingBuffer { -public: - - /** @param size Size in bytes. - */ - RingBuffer(size_t size) - : _size(size) - , _buf(new T[size]) - { - reset(); - assert(read_space() == 0); - assert(write_space() == size - 1); - } - - virtual ~RingBuffer() { - delete[] _buf; - } - - /** Reset(empty) the ringbuffer. - * NOT thread safe. - */ - void reset() { - g_atomic_int_set(&_write_ptr, 0); - g_atomic_int_set(&_read_ptr, 0); - } - - size_t write_space() const { - - const size_t w = g_atomic_int_get(&_write_ptr); - const size_t r = g_atomic_int_get(&_read_ptr); - - if (w > r) { - return ((r - w + _size) % _size) - 1; - } else if(w < r) { - return (r - w) - 1; - } else { - return _size - 1; - } - } - - size_t read_space() const { - - const size_t w = g_atomic_int_get(&_write_ptr); - const size_t r = g_atomic_int_get(&_read_ptr); - - if (w > r) { - return w - r; - } else { - return (w - r + _size) % _size; - } - } - - size_t capacity() const { return _size; } - - size_t read(size_t size, T* dst); - void write(size_t size, const T* src); - - bool full_read(size_t size, T* dst); - -protected: - mutable gint _write_ptr; - mutable gint _read_ptr; - - size_t _size; ///< Size (capacity) in bytes - T* _buf; ///< size, event, size, event... -}; - - -/** Read from the ringbuffer. - * - * Note that a full read may not be done if the data wraps around. - * Caller must check return value and call again if necessary, or use the - * full_read method which does this automatically. - */ -template<typename T> -size_t -RingBuffer<T>::read(size_t size, T* dst) -{ - const size_t priv_read_ptr = g_atomic_int_get(&_read_ptr); - - const size_t read_size = (priv_read_ptr + size < _size) - ? size - : _size - priv_read_ptr; - - memcpy(dst, &_buf[priv_read_ptr], read_size); - - g_atomic_int_set(&_read_ptr, (priv_read_ptr + read_size) % _size); - - return read_size; -} - - -template<typename T> -inline void -RingBuffer<T>::write(size_t size, const T* src) -{ - const size_t priv_write_ptr = g_atomic_int_get(&_write_ptr); - - if (priv_write_ptr + size <= _size) { - memcpy(&_buf[priv_write_ptr], src, size); - g_atomic_int_set(&_write_ptr, (priv_write_ptr + size) % _size); - } else { - const size_t this_size = _size - priv_write_ptr; - assert(this_size < size); - assert(priv_write_ptr + this_size <= _size); - memcpy(&_buf[priv_write_ptr], src, this_size); - memcpy(&_buf[0], src+this_size, size - this_size); - g_atomic_int_set(&_write_ptr, size - this_size); - } -} - - -template<typename T> -bool -RingBuffer<T>::full_read(size_t size, T* dst) -{ - if (read_space() < size) - return false; - - const size_t read_size = read(size, dst); - - if (read_size < size) - read(size - read_size, dst + read_size); - - return true; -} - - -} // namespace Raul - -#endif // RAUL_RING_BUFFER_H - |