From da05332685492f82d46f682846cbabbabd2927e6 Mon Sep 17 00:00:00 2001
From: Alvise De Faveri <alvise.defaveri@skywarder.eu>
Date: Sat, 18 Nov 2017 15:57:14 +0100
Subject: [PATCH] Add buffer file
---
src/shared/drivers/gamma868/CircularBuffer.h | 157 +++++++++++++++++++
1 file changed, 157 insertions(+)
create mode 100644 src/shared/drivers/gamma868/CircularBuffer.h
diff --git a/src/shared/drivers/gamma868/CircularBuffer.h b/src/shared/drivers/gamma868/CircularBuffer.h
new file mode 100644
index 000000000..17420e20b
--- /dev/null
+++ b/src/shared/drivers/gamma868/CircularBuffer.h
@@ -0,0 +1,157 @@
+/* Copyright (c) 2017 Skyward Experimental Rocketry
+ * Authors: Alvise de'Faveri Tron
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef CIRCULARBUFFER_H
+#define CIRCULARBUFFER_H
+
+#include "gamma_config.h"
+#include <pthread.h>
+#include <stdio.h>
+
+class CircularBuffer {
+ public:
+
+ /*
+ * Creates a buffer with fixed dimension (decided in gamma_config).
+ */
+ CircularBuffer(){};
+
+ /*
+ * TODO check if it's good practice.
+ * Creates a buffer with given dimension (uses new!).
+ *
+ CircularBuffer(int totalSize){
+ this.totalSize = totalSize;
+ buffer = new char[totalSize];
+ }
+
+ */
+
+ /*
+ * Calculates the occupied portion of the buffer.
+ */
+
+ unsigned int size()
+ {
+ if(last == -1)return totalSize;
+ else if(last < first) return totalSize - (first - last);
+ else return last - first;
+ }
+
+ /*
+ * Reads at maximum n chars from the buffer and stores them in *buf
+ * in subsequent positions starting from offset.
+ * Returns the number of characters stored (could be less than n
+ * if the buffer contains less than n characters).
+ */
+ unsigned int read(unsigned int n, char *buf, int offset)
+ {
+ unsigned int nChar = size() > n ? n : size();
+ int i = 0;
+
+// printf("BEFORE READING\n");
+// print();
+
+ pthread_mutex_lock(&outBufMutex);
+ for(i = 0; i < (int)nChar; i++)
+ {
+ if(i==0 && last == -1) last = first;
+
+ buf[offset+i] = buffer[first];
+ first++;
+ if(first == totalSize)
+ first = 0;
+ if(first == last)
+ break;
+ }
+ pthread_mutex_unlock(&outBufMutex);
+
+// printf("AFTER READING\n");
+// print();
+
+ return i;
+ }
+
+ /*
+ * Writes n characters in the buffer (or until it is full).
+ * Returns the number of chars effectively written.
+ */
+ unsigned int write(unsigned int n, const char *chars)
+ {
+ unsigned int i = 0;
+
+// printf("BEFORE WRITING %s\n", chars);
+// print();
+
+ pthread_mutex_lock(&outBufMutex);
+ if((int)size() < totalSize)
+ {
+ for(i = 0; i < n; i++)
+ {
+ buffer[last] = chars[i];
+ last++;
+
+ if(last == totalSize)
+ last = 0;
+ if(last == first)
+ {
+ last =-1;
+ break;
+ }
+ }
+ }
+ pthread_mutex_unlock(&outBufMutex);
+
+// printf("AFTER WRITING\n");
+// print();
+
+ return i;
+ }
+
+ /*
+ * TODO toString.
+ * Prints the whole content of the buffer (for debug pupouses).
+
+ void print(){
+ printf("Buffer: first %d last %d occupied %u total size %d\n",
+ first, last, size(), totalSize);
+
+ int offset = first;
+ for (int i = 0; i < totalSize; i++){
+ if (offset + i == totalSize) offset = -i;
+ printf("%c", buffer[i]);
+ }
+ printf("\n");
+ }
+ */
+
+
+ private:
+ int totalSize = OUT_BUFFER_SIZE;
+ int first = 0;
+ int last = 0;
+ char buffer[OUT_BUFFER_SIZE];
+
+ pthread_mutex_t outBufMutex;
+};
+
+#endif /* CIRCULARBUFFER_H */
\ No newline at end of file
--
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