1 #pragma once
2
3 #include <iostream>
4 #include <string>
5
6 class cyclebuffer
7 {
8 protected:
9 volatile int32_t m_nReadIndex;
10 volatile int32_t m_nWriteIndex;
11 volatile int32_t m_nDataSize; //有效数据大小
12 volatile int32_t m_nBufSize; //总buf大小
13 uint_8 *m_pBuf;
14
15 public:
16 //剩余空间数
17 int32_t Space()
18 {
19 return m_nBufSize-m_nDataSize;
20 }
21
22 //获取buf的总大小
23 int32_t Capatity()
24 {
25 return m_nBufSize;
26 }
27
28 //获取有效数据长度
29 int32_t Size()
30 {
31 return m_nDataSize;
32 }
33 //清空
34 void Reset()
35 {
36 m_nReadIndex = 0;
37 m_nwriteIndex = 0;
38 m_nDataSize = 0;
39 }
40
41 //增加nSize个字节
42 int32_t Grow(int32_t nSize)
43 {
44
45 }
46
47 //写到写列表的头部---针对新数据
48 int32_t WriteToHead(const uint8_t *pBuf, int32_t nDataSize)
49 {
50 if(nDataSize < 0 || pBuf == NULL)
51 {
52 return 0;
53 }
54
55 //空间不够
56 if(m_nDataSize + nDataSize > m_nBufsize)
57 {
58 if(Grow((m_nDataSize+nDataSize) - m_nDataSize) <= 0)
59 {
60 return 0;
61 }
62 }
63
64 if(m_nWriteIndex < m_nReadIndex)
65 {
66 memcpy(&m_pBuf[m_nReadIndex-nDataSize], pBuf, nDataSize);
67 m_nReadIndex -= nDataSize;
68 }
69 else if(m_nWriteIndex == m_nReadIndex)
70 {
71 return Write(pBuf, nDataSize);
72 }
73 else
74 {
75 int32_t nLeftDataSize = (nDataSize-m_nReadIndex<0)?nDataSize:m_nReadIndex;
76 if(nLeftDataSize < nDataSize) //此时nLeftDataSize == m_nReadIndex,m_nReadIndex前面的空间不够
77 {
78 int32_t nTailDataSize = nDataSize - nLeftDataSize;
79 int32_t nWriteIndex = m_nBufSize - nTailDatasize;
80 memcpy(&m_pBuf[nWriteIndex], pBuf, nDataSize-nLeftDataSize); //从内存最后向前写
81 memcpy(&m_pBuf[0], pBuf+nTailDataSize, nLeftDataSize);
82 m_nReadIndex = nWriteIndex;
83 }
84 else
85 {
86 if(m_nReadIndex-nDataSize < 0)
87 {
88 return 0;
89 }
90 memcpy(&m_pBuf[m_nReadIndex-nDataSize], pBuf, nDataSize);
91 m_nReadIndex -= nDataSize;
92 }
93 }
94 m_nDataSize += nDataSize;
95 return nDataSize;
96 }
97
98 //写到列表的尾部
99 int32_t Write(const uint8_t *pBuf, int32_t nDataSize)
100 {
101 if(nDataSize <= 0 || NULL == pBuf)
102 {
103 return 0;
104 }
105
106 if(nDataSize + m_nDataSize > m_nBufSize)
107 {
108 if(Grow((nDataSize+nBufSize)-m_nDataSize) <= 0)
109 {
110 return 0;
111 }
112 }
113
114 if(m_nWriteIndex < m_nReadIndex)
115 {
116 memcpy(&m_pBuf[m_nWriteIndex], pBuf, nDataSize);
117 m_nWriteIndex += nDataSize;
118 }
119 else
120 {
121 int32_t nLeftDataSize = m_nBufSize - m_nWriteIndex;
122 if(nLeftDataSize < nDataSize)
123 {
124 {
125 memcpy(&m_pBuf[m_nWriteIndex], pBuf, nLeftDataSize);
126 memcpy(&m_pBuf[0], pBuf+nLeftDataSize, nDataSize-nLeftDataSize);
127 m_nwriteIndex = nDataSize - nLeftDataSize;
128 }
129 else
130 {
131 memcpy(&m_pBuf[m_nWriteIndex], pBuf, nDataSize);
132 m_nWriteIndex += nDataSize;
133 }
134 }
135 m_nDataSize += nDataSize;
136 return nDataSize;
137 }
138
139 //读取 读列表的头部内存
140 int32_t Read(uint8_t *pBuf, const int32_t nWantSize)
141 {
142 if(nWantSize <= 0 || NULL == pBuf)
143 {
144 return 0;
145 }
146
147 int32_t nDataSize = ((m_nDataSize < nWantSize)?m_nDataSize : nWantSize);
148 if(nDataSize<=0)
149 {
150 return 0;
151 }
152 if(m_nReadIndex < m_nWriteIndex)
153 {
154 memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
155 m_nReadIndex += nDataSize;
156 }
157 else
158 {
159 int32_t nLeftDataSize = m_nBufSize - m_nReadIndex;
160 if(nLeftDataSize < nDataSize)
161 {
162 memcpy(pBuf, &m_pBuf[m_nReadIndex], nLeftDataSize);
163 memcpy(pBuf+nLeftDataSize, &m_pBuf[0], nDataSize-nLeftDataSize);
164 m_nReadIndex = nDataSize-nLeftDataSize;
165 }
166 else
167 {
168 memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
169 m_nReadIndex += nDataSize;
170 }
171 }
172 m_nDataSize -= nDataSize;
173 return nDataSize;
174 }
175
176
177 //读取数据但是不修改读索引
178 int32_t PeekRead(uint8_t *pBuf, const int32_t nWantSize)
179 {
180 if(nWantSize <= 0 || pBuf == NULL)
181 {
182 return 0;
183 }
184
185 int32_t nDataSize = ((m_nDataSize < nWantSize) ? m_nDataSize : nWantSize);
186 if(m_nReadIndex < m_nWriteIndex)
187 {
188 memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
189 }
190 else if(m_nReadIndex == m_nWriteIndex)
191 {
192 return 0;
193 }
194 else
195 {
196 int32_t nLeftDataSize = m_nBufSize - m_nReadIndex;
197 if(nLeftDataSize < nDataSize)
198 {
199 memcpy(pBuf, &m_pBuf[m_nReadIndex], nLeftDataSize);
200 memcpy(pBuf+nLeftDataSize, &m_pBuf[0], nDataSize-nLeftDataSize);
201 }
202 else
203 {
204 memcpy(pBuf, &m_pBuf[m_nReadIndex], nDataSize);
205 }
206 }
207 return nDataSize;
208 }
209
210 };
网络收发之cycleBuf
时间： 2024-10-09 04:41:22