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IN NO EVENT SHALL THE COPYRIGHT HOLDER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- * Notice of Export Control Law * =============================================== * Huawei LiteOS may be subject to applicable export control laws and regulations, which might * include those applicable to Huawei LiteOS of U.S. and the country in which you are located. * Import, export and usage of Huawei LiteOS in any manner by you shall be in compliance with such * applicable export control laws and regulations. *---------------------------------------------------------------------------*/ /** * DATE AUTHOR INSTRUCTION * 2019-04-29 10:34 zhangqianfu The first version * */ #include #include #include #include int ring_buffer_init(tag_ring_buffer_t *ring,unsigned char *buf, int buflen,int offset,int datalen) { int ret = -1; if((NULL == ring)) { return ret; } ring->buf = buf; ring->buflen = buflen; ring->datalen = datalen; ring->dataoff = offset; ret = 0; return ret; } int ring_buffer_write(tag_ring_buffer_t *ring,unsigned char *buf, int len) { int ret = -1; int cpylen; //the current time we should move int lenleft; //and how many data still left to move int offset; unsigned char *src; unsigned char *dst; if((NULL == ring)||(NULL == buf)||(0 == len)) { return ret;//which means parameters error } if((ring->datalen == ring->buflen)|| (ring->buflen <= 0)) { ret = 0; return ret;//which means you could copy nothing here } ret = len > (ring->buflen-ring->datalen)?(ring->buflen-ring->datalen):len; //now let us think the method to fill the data,take care of the roll back lenleft = ret; src = buf; if((ring->dataoff+ring->datalen)>ring->buflen) //which means the data has roll back { offset = (ring->dataoff+ring->datalen)%ring->buflen; //we could move it one time cpylen = lenleft; dst = ring->buf + offset; if(cpylen > 0) { (void) memcpy(dst,src,cpylen); ring->datalen += cpylen; lenleft -= cpylen; } } else if((ring->dataoff+ring->datalen + lenleft)>ring->buflen) //which means the data will be roll back { //which means roll back,we should copy some here to the tail offset = ring->dataoff + ring->datalen; cpylen = ring->buflen - offset; dst = ring->buf + offset; (void) memcpy(dst,src,cpylen); src += cpylen; ring->datalen += cpylen; lenleft -= cpylen; } //here means we could move it by one time if(lenleft > 0) { offset = (ring->dataoff+ring->datalen)%ring->buflen; //we could move it one time cpylen = lenleft; dst = ring->buf + offset; (void) memcpy(dst,src,cpylen); ring->datalen += cpylen; } return ret; } int ring_buffer_read(tag_ring_buffer_t *ring,unsigned char *buf, int len) { int ret = -1; int cpylen; //the current time we should move int lenleft; //and how many data still left to move int offset; unsigned char *src; unsigned char *dst; if((NULL == ring)||(NULL == buf)||(0 == len)) { return ret;//which means parameters error } if((ring->datalen == 0) || (ring->buflen <= 0)) { ret = 0; return ret;//which means you could copy nothing here } ret = len > ring->datalen?ring->datalen:len; //now let us think the method to fill the data,take care of the roll back lenleft = ret; dst = buf; if(ring->dataoff >= (ring->buflen - lenleft)) //which means the data has roll back { offset =ring->dataoff; //we cpy part cpylen = ring->buflen - ring->dataoff; src = ring->buf + offset; if(cpylen > 0) { (void) memcpy(dst,src,cpylen); ring->dataoff = (ring->dataoff + cpylen)%ring->buflen; ring->datalen -= cpylen; lenleft -= cpylen; dst += cpylen; } } //here means we could move it by one time if(lenleft > 0) { offset =ring->dataoff; //we cpy part cpylen = lenleft; src = ring->buf + offset; (void) memcpy(dst,src,cpylen); ring->dataoff = ring->dataoff + cpylen; ring->datalen -= cpylen; } return ret; } int ring_buffer_datalen(tag_ring_buffer_t *ring) { int ret = -1; if(NULL != ring) { ret = ring->datalen; } return ret; } int ring_buffer_freespace(tag_ring_buffer_t *ring) { int ret = -1; if(NULL != ring) { ret = ring->buflen-ring->datalen; } return ret; } int ring_buffer_reset(tag_ring_buffer_t *ring) { int ret = -1; if(NULL != ring) { ring->datalen = 0; ring->dataoff = 0; ret = 0; } return ret; } int ring_buffer_deinit(tag_ring_buffer_t *ring) { int ret = -1; if(NULL != ring) { (void) memset(ring,0,sizeof(tag_ring_buffer_t)); ret = 0; } return ret; }