LightweightRingBuff.h 5.26 KB
 Dean Camera committed Jun 06, 2010 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 /* LUFA Library Copyright (C) Dean Camera, 2010. dean [at] fourwalledcubicle [dot] com www.fourwalledcubicle.com */ /* Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. The author disclaim all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software. */ /** \file * * Ultra lightweight ring buffer, for fast insertion/deletion. */ #ifndef _ULW_RING_BUFF_H_ #define _ULW_RING_BUFF_H_ /* Includes: */  Dean Camera committed Jun 06, 2010 40 41  #include  Dean Camera committed Jun 06, 2010 42 43 44 45  #include #include /* Defines: */  Dean Camera committed Jun 06, 2010 46  /** Size of each ring buffer, in data elements - must be between 1 and 255. */  Dean Camera committed Jun 24, 2010 47  #define BUFFER_SIZE 255  Dean Camera committed Jun 06, 2010 48 49 50 51 52  /** Type of data to store into the buffer. */ #define RingBuff_Data_t uint8_t /* Type Defines: */  Dean Camera committed Jun 06, 2010 53 54 55  /** Type define for a new ring buffer object. Buffers should be initialized via a call to * \ref RingBuffer_InitBuffer() before use. */  Dean Camera committed Jun 06, 2010 56 57  typedef struct {  Dean Camera committed Jun 06, 2010 58 59 60 61  RingBuff_Data_t Buffer[BUFFER_SIZE]; /**< Internal ring buffer data, referenced by the buffer pointers. */ RingBuff_Data_t* In; /**< Current storage location in the circular buffer */ RingBuff_Data_t* Out; /**< Current retrieval location in the circular buffer */ uint8_t Count; /**< Total number of bytes stored in the circular buffer */  Dean Camera committed Jun 06, 2010 62 63 64  } RingBuff_t; /* Inline Functions: */  Dean Camera committed Jun 06, 2010 65 66 67 68  /** Initializes a ring buffer ready for use. Buffers must be initialized via this function * before any operations are called upon them. Already initialized buffers may be reset * by re-initializing them using this function. *  Dean Camera committed Jun 10, 2010 69  * \param[out] Buffer Pointer to a ring buffer structure to initialize  Dean Camera committed Jun 06, 2010 70  */  Dean Camera committed Jun 06, 2010 71 72  static inline void RingBuffer_InitBuffer(RingBuff_t* const Buffer) {  Dean Camera committed Jun 06, 2010 73 74  Buffer->In = Buffer->Buffer; Buffer->Out = Buffer->Buffer;  Dean Camera committed Jun 06, 2010 75 76 77  Buffer->Count = 0; }  78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97  /** Atomically determines if the specified ring buffer contains any free space. This should * be tested before storing data to the buffer, to ensure that no data is lost due to a * buffer overrun. * * \param[in,out] Buffer Pointer to a ring buffer structure to insert into * * \return Boolean true if the buffer contains no free space, false otherwise */ static inline bool RingBuffer_IsFull(RingBuff_t* const Buffer) { bool IsFull; ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { IsFull = (Buffer->Count == BUFFER_SIZE); } return IsFull; }  Dean Camera committed Jul 12, 2010 98  /** Atomically inserts an element into the ring buffer.  Dean Camera committed Jun 06, 2010 99  *  Dean Camera committed Jun 10, 2010 100 101  * \param[in,out] Buffer Pointer to a ring buffer structure to insert into * \param[in] Data Data element to insert into the buffer  Dean Camera committed Jun 06, 2010 102  */  Dean Camera committed Jul 21, 2010 103 104  static inline void RingBuffer_AtomicInsert(RingBuff_t* const Buffer, const RingBuff_Data_t Data)  Dean Camera committed Jun 06, 2010 105  {  Dean Camera committed Jun 06, 2010 106 107 108 109 110 111 112 113 114  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { *Buffer->In = Data; if (++Buffer->In == &Buffer->Buffer[BUFFER_SIZE]) Buffer->In = Buffer->Buffer; Buffer->Count++; }  Dean Camera committed Jun 06, 2010 115 116  }  Dean Camera committed Jul 12, 2010 117  /** Atomically retrieves an element from the ring buffer.  Dean Camera committed Jun 06, 2010 118  *  Dean Camera committed Jun 10, 2010 119  * \param[in,out] Buffer Pointer to a ring buffer structure to retrieve from  Dean Camera committed Jun 06, 2010 120 121 122  * * \return Next data element stored in the buffer */  Dean Camera committed Jul 12, 2010 123  static inline RingBuff_Data_t RingBuffer_AtomicRemove(RingBuff_t* const Buffer)  Dean Camera committed Jun 06, 2010 124  {  Dean Camera committed Jun 06, 2010 125 126 127 128 129 130 131 132 133 134 135  RingBuff_Data_t Data; ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { Data = *Buffer->Out; if (++Buffer->Out == &Buffer->Buffer[BUFFER_SIZE]) Buffer->Out = Buffer->Buffer; Buffer->Count--; }  Dean Camera committed Jun 06, 2010 136 137 138 139  return Data; }  Dean Camera committed Jul 12, 2010 140 141 142 143 144  /** Inserts an element into the ring buffer. * * \param[in,out] Buffer Pointer to a ring buffer structure to insert into * \param[in] Data Data element to insert into the buffer */  Dean Camera committed Jul 21, 2010 145 146  static inline void RingBuffer_Insert(RingBuff_t* const Buffer, const RingBuff_Data_t Data)  Dean Camera committed Jul 12, 2010 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173  { *Buffer->In = Data; if (++Buffer->In == &Buffer->Buffer[BUFFER_SIZE]) Buffer->In = Buffer->Buffer; Buffer->Count++; } /** Retrieves an element from the ring buffer. * * \param[in,out] Buffer Pointer to a ring buffer structure to retrieve from * * \return Next data element stored in the buffer */ static inline RingBuff_Data_t RingBuffer_Remove(RingBuff_t* const Buffer) { RingBuff_Data_t Data = *Buffer->Out; if (++Buffer->Out == &Buffer->Buffer[BUFFER_SIZE]) Buffer->Out = Buffer->Buffer; Buffer->Count--; return Data; }  Dean Camera committed Jun 06, 2010 174 #endif  Dean Camera committed May 26, 2010 175