add ring buffer implementation

src/btstack_ring_buffer.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2016 BlueKitchen GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holders nor the names of
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ * 4. Any redistribution, use, or modification is done solely for
+ *    personal benefit and not for any commercial purpose or for
+ *    monetary gain.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
+ * RINGWALD 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.
+ *
+ * Please inquire about commercial licensing options at 
+ * contact@bluekitchen-gmbh.com
+ *
+ */
+
+/*
+ *  btstack_ring_buffer.c
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "btstack_ring_buffer.h"
+
+#define ERROR_CODE_MEMORY_CAPACITY_EXCEEDED 0x07
+
+// init ring buffer
+void btstack_ring_buffer_init(btstack_ring_buffer_t * ring_buffer, uint8_t * storage, uint16_t storage_size){
+    ring_buffer->storage = storage;
+    ring_buffer->size = storage_size;
+    ring_buffer->last_read_index = 0;
+    ring_buffer->last_written_index = 0;   
+    ring_buffer->full = 0;
+}
+
+int btstack_ring_buffer_bytes_available(btstack_ring_buffer_t * ring_buffer){
+    if (ring_buffer->full) return ring_buffer->size;
+    int diff = ring_buffer->last_written_index - ring_buffer->last_read_index;
+    if (diff >= 0) return diff;
+    return diff + ring_buffer->size;
+}
+
+// test if ring buffer is empty
+int btstack_ring_buffer_empty(btstack_ring_buffer_t * ring_buffer){
+    return btstack_ring_buffer_bytes_available(ring_buffer) == 0;
+}
+
+// 
+int btstack_ring_buffer_bytes_free(btstack_ring_buffer_t * ring_buffer){
+    return ring_buffer->size - btstack_ring_buffer_bytes_available(ring_buffer);
+}
+
+// add byte block to ring buffer, 
+int btstack_ring_buffer_write(btstack_ring_buffer_t * ring_buffer, uint8_t * data, uint16_t data_length){
+    if (btstack_ring_buffer_bytes_free(ring_buffer) < data_length){
+        return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
+    }
+    // printf("\n\nbtstack_ring_buffer_write %d, ring_buffer->size %d\n", data_length, ring_buffer->size);
+    int count = 0;
+    while (count < data_length){
+        if (ring_buffer->last_written_index < ring_buffer->size - 1){
+            ring_buffer->last_written_index++;
+        } else {
+            ring_buffer->last_written_index = 0;
+        }
+        ring_buffer->storage[ring_buffer->last_written_index] = data[count++];
+    }
+    if (ring_buffer->last_written_index == ring_buffer->last_read_index){
+        ring_buffer->full = 1;
+    }
+    return 0;
+} 
+
+// fetch data_length bytes from ring buffer
+void btstack_ring_buffer_read(btstack_ring_buffer_t * ring_buffer, uint8_t * data, uint16_t data_length, uint16_t * number_of_bytes_read){
+    uint32_t count = 0;
+    while (*number_of_bytes_read < data_length && btstack_ring_buffer_bytes_available(ring_buffer)){
+        if (ring_buffer->last_read_index < ring_buffer->last_written_index ) {
+            ring_buffer->last_read_index++;
+        } else {
+            if (ring_buffer->last_read_index < ring_buffer->size - 1){
+                ring_buffer->last_read_index++;
+            } else {
+                ring_buffer->last_read_index = 0;
+            }
+        }
+        ring_buffer->full = 0;
+        data[count++] = ring_buffer->storage[ring_buffer->last_read_index];
+    }
+    *number_of_bytes_read = count;
+} 
+

src/btstack_ring_buffer.h

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2016 BlueKitchen GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holders nor the names of
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ * 4. Any redistribution, use, or modification is done solely for
+ *    personal benefit and not for any commercial purpose or for
+ *    monetary gain.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
+ * RINGWALD 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.
+ *
+ * Please inquire about commercial licensing options at 
+ * contact@bluekitchen-gmbh.com
+ *
+ */
+
+/*
+ *  btstack_ring_buffer.h
+ */
+
+#ifndef __BTSTACK_RING_BUFFER_H
+#define __BTSTACK_RING_BUFFER_H
+
+#if defined __cplusplus
+extern "C" {
+#endif
+
+typedef struct btstack_ring_buffer {
+    uint8_t  * storage;
+    uint16_t size;    
+    uint16_t last_read_index;
+    uint16_t last_written_index;
+    uint8_t  full;
+} btstack_ring_buffer_t;
+
+// init ring buffer
+void btstack_ring_buffer_init(btstack_ring_buffer_t * ring_buffer, uint8_t * storage, uint16_t storage_size);
+
+// test if ring buffer is empty
+int btstack_ring_buffer_empty(btstack_ring_buffer_t * ring_buffer);
+
+// number of bytes available for read 
+int btstack_ring_buffer_bytes_available(btstack_ring_buffer_t * ring_buffer);
+
+// free space for write given in number of bytes
+int btstack_ring_buffer_bytes_free(btstack_ring_buffer_t * ring_buffer);
+
+// add byte block to ring buffer, 
+int btstack_ring_buffer_write(btstack_ring_buffer_t * ring_buffer, uint8_t * data, uint16_t data_length); 
+
+// fetch data_length bytes from ring buffer
+void btstack_ring_buffer_read(btstack_ring_buffer_t * ring_buffer, uint8_t * data, uint16_t data_length, uint16_t * number_of_bytes_read); 
+
+
+#if defined __cplusplus
+}
+#endif
+
+#endif // __BTSTACK_RING_BUFFER_H

test/ring_buffer/.gitignore

@@ -0,0 +1 @@
+btstack_ring_buffer_test

test/ring_buffer/Makefile

@@ -0,0 +1,28 @@
+CC=g++
+
+# Requirements: cpputest.github.io
+
+BTSTACK_ROOT =  ../..
+CPPUTEST_HOME = ${BTSTACK_ROOT}/test/cpputest
+
+CFLAGS  = -g -Wall -I. -I../ -I${BTSTACK_ROOT}/src
+LDFLAGS += -lCppUTest -lCppUTestExt
+
+VPATH += ${BTSTACK_ROOT}/src
+
+COMMON = \
+    btstack_ring_buffer.c \
+
+COMMON_OBJ = $(COMMON:.c=.o)
+
+all: btstack_ring_buffer_test
+
+btstack_ring_buffer_test: ${COMMON_OBJ} btstack_ring_buffer_test.c
+	${CC} $^ ${CFLAGS} ${LDFLAGS} -o $@
+
+test: all
+	./btstack_ring_buffer_test
+	
+clean:
+	rm -fr btstack_ring_buffer_test *.dSYM *.o ../src/*.o
+	

test/ring_buffer/btstack_ring_buffer_test.c

@@ -0,0 +1,75 @@
+#include "CppUTest/TestHarness.h"
+#include "CppUTest/CommandLineTestRunner.h"
+#include "btstack_ring_buffer.h"
+
+static  uint8_t storage[10];
+
+TEST_GROUP(RingBuffer){
+    btstack_ring_buffer_t ring_buffer;
+    int storage_size;
+
+    void setup(void){
+        storage_size = sizeof(storage);
+        memset(storage, 0, storage_size);
+        btstack_ring_buffer_init(&ring_buffer, storage, storage_size);
+    }
+};
+
+TEST(RingBuffer, EmptyBuffer){
+    CHECK_TRUE(btstack_ring_buffer_empty(&ring_buffer));
+    CHECK_EQUAL(0, btstack_ring_buffer_bytes_available(&ring_buffer));
+    CHECK_EQUAL(storage_size, btstack_ring_buffer_bytes_free(&ring_buffer));
+}
+
+TEST(RingBuffer, WriteBuffer){
+    uint8_t test_write_data[] = {1,2,3,4, 5};
+    int test_data_size = sizeof(test_write_data);
+    uint8_t test_read_data[test_data_size];
+
+    btstack_ring_buffer_write(&ring_buffer, test_write_data, test_data_size);
+    CHECK_EQUAL(test_data_size, btstack_ring_buffer_bytes_available(&ring_buffer));
+
+    uint16_t number_of_bytes_read = 0;
+    memset(test_read_data, 0, test_data_size);
+    btstack_ring_buffer_read(&ring_buffer, test_read_data, test_data_size, &number_of_bytes_read); 
+    
+    CHECK_EQUAL(0, memcmp(test_write_data, test_read_data, test_data_size));
+
+}
+
+TEST(RingBuffer, WriteFullBuffer){    
+    uint8_t test_write_data[] = {1,2,3,4,5,6,7,8,9,10};
+    int test_data_size = sizeof(test_write_data);
+    uint8_t test_read_data[test_data_size];
+
+    btstack_ring_buffer_write(&ring_buffer, test_write_data, test_data_size);
+    CHECK_EQUAL(test_data_size, btstack_ring_buffer_bytes_available(&ring_buffer));
+
+    memset(test_read_data, 0, test_data_size);
+    uint16_t number_of_bytes_read = 0;
+    btstack_ring_buffer_read(&ring_buffer, test_read_data, test_data_size, &number_of_bytes_read); 
+
+    CHECK_EQUAL(0, memcmp(test_write_data, test_read_data, test_data_size));
+}
+
+
+TEST(RingBuffer, ReadWrite){    
+    uint8_t test_write_data[] = {1,2,3,4};
+    int test_data_size = sizeof(test_write_data);
+    uint8_t test_read_data[test_data_size];
+
+    int i;
+    for (i=0;i<30;i++){
+        btstack_ring_buffer_write(&ring_buffer, test_write_data, test_data_size);
+        CHECK_EQUAL(test_data_size, btstack_ring_buffer_bytes_available(&ring_buffer));
+
+        memset(test_read_data, 0, test_data_size);
+        uint16_t number_of_bytes_read = 0;
+        btstack_ring_buffer_read(&ring_buffer, test_read_data, test_data_size, &number_of_bytes_read); 
+        CHECK_EQUAL(0, memcmp(test_write_data, test_read_data, test_data_size));
+    }
+}
+
+int main (int argc, const char * argv[]){
+    return CommandLineTestRunner::RunAllTests(argc, argv);
+}