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00018 #ifndef RAUL_RING_BUFFER_HPP
00019 #define RAUL_RING_BUFFER_HPP
00020
00021 #include <cassert>
00022 #include <glib.h>
00023
00024 namespace Raul {
00025
00026
00031 template <typename T>
00032 class RingBuffer {
00033 public:
00034
00037 RingBuffer(size_t size)
00038 : _size(size)
00039 , _buf(new T[size])
00040 {
00041 reset();
00042 assert(read_space() == 0);
00043 assert(write_space() == size - 1);
00044 }
00045
00046 virtual ~RingBuffer() {
00047 delete[] _buf;
00048 }
00049
00053 void reset() {
00054 g_atomic_int_set(&_write_ptr, 0);
00055 g_atomic_int_set(&_read_ptr, 0);
00056 }
00057
00058 size_t write_space() const {
00059
00060 const size_t w = g_atomic_int_get(&_write_ptr);
00061 const size_t r = g_atomic_int_get(&_read_ptr);
00062
00063 if (w > r) {
00064 return ((r - w + _size) % _size) - 1;
00065 } else if(w < r) {
00066 return (r - w) - 1;
00067 } else {
00068 return _size - 1;
00069 }
00070 }
00071
00072 size_t read_space() const {
00073
00074 const size_t w = g_atomic_int_get(&_write_ptr);
00075 const size_t r = g_atomic_int_get(&_read_ptr);
00076
00077 if (w > r) {
00078 return w - r;
00079 } else {
00080 return (w - r + _size) % _size;
00081 }
00082 }
00083
00084 size_t capacity() const { return _size; }
00085
00086 size_t read(size_t size, T* dst);
00087 void write(size_t size, const T* src);
00088
00089 bool full_read(size_t size, T* dst);
00090
00091 protected:
00092 mutable gint _write_ptr;
00093 mutable gint _read_ptr;
00094
00095 size_t _size;
00096 T* _buf;
00097 };
00098
00099
00106 template<typename T>
00107 size_t
00108 RingBuffer<T>::read(size_t size, T* dst)
00109 {
00110 const size_t priv_read_ptr = g_atomic_int_get(&_read_ptr);
00111
00112 const size_t read_size = (priv_read_ptr + size < _size)
00113 ? size
00114 : _size - priv_read_ptr;
00115
00116 memcpy(dst, &_buf[priv_read_ptr], read_size);
00117
00118 g_atomic_int_set(&_read_ptr, (priv_read_ptr + read_size) % _size);
00119
00120 return read_size;
00121 }
00122
00123
00124 template<typename T>
00125 inline void
00126 RingBuffer<T>::write(size_t size, const T* src)
00127 {
00128 const size_t priv_write_ptr = g_atomic_int_get(&_write_ptr);
00129
00130 if (priv_write_ptr + size <= _size) {
00131 memcpy(&_buf[priv_write_ptr], src, size);
00132 g_atomic_int_set(&_write_ptr, (priv_write_ptr + size) % _size);
00133 } else {
00134 const size_t this_size = _size - priv_write_ptr;
00135 assert(this_size < size);
00136 assert(priv_write_ptr + this_size <= _size);
00137 memcpy(&_buf[priv_write_ptr], src, this_size);
00138 memcpy(&_buf[0], src+this_size, size - this_size);
00139 g_atomic_int_set(&_write_ptr, size - this_size);
00140 }
00141 }
00142
00143
00144 template<typename T>
00145 bool
00146 RingBuffer<T>::full_read(size_t size, T* dst)
00147 {
00148 if (read_space() < size)
00149 return false;
00150
00151 const size_t read_size = read(size, dst);
00152
00153 if (read_size < size)
00154 read(size - read_size, dst + read_size);
00155
00156 return true;
00157 }
00158
00159
00160 }
00161
00162 #endif // RAUL_RING_BUFFER_HPP
00163