Add ringbuffer

components/f1ll/CMakeLists.txt

@@ -3,6 +3,7 @@ add_library(f1ll STATIC
     src/dma_helper.cpp
     src/str_util.cpp
     src/console_handler.cpp
+    src/ringbuffer.cpp
 )
 
 target_include_directories(f1ll PUBLIC

components/f1ll/inc/f1ll/ringbuffer.h

@@ -0,0 +1,70 @@
+/*
+ * ringbuffer.h
+ *
+ *  Created on: Sep 14, 2021
+ *      Author: Attila Body
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+namespace f1ll {
+
+class ringbuffer
+{
+public:
+  ringbuffer(uint8_t *buffer, uint16_t size);
+
+  /// @brief Copies data to the ring buffer (without committing it) The amount of the committed data in the buffer
+  ///        should not exceed the size of the buffer.
+  /// @param data Pointer to the data to copy
+  /// @param len Length of the data to copy
+  uint16_t put(uint8_t const *data_buffer, uint16_t len);
+
+  /// @brief Commits the data already placed into the buffer and notifies the consumer about it's availability
+  void commit();
+
+  /// @brief Waits until all the data from the ring buffer gets consumed.
+  // void flush();
+
+  /// @brief Gets a pointer to the next chunk of committed data in the buffer without registering the consumption.
+  ///        The caller should also call report_consumption using the returned chunk length after
+  ///        it finished processing the data.
+  /// @param[in]  len_requested Length of the data requested from the buffer. The length of the actual data provided
+  ///             might be actually smaller (because either reaching the end of the buffer or not enough data in the
+  ///             buffer).
+  /// @param[out] data Receives a pointer to the first byte of the available data in the buffer
+  /// @param[out] len Receives the length of the chunk available in the buffer. Will not exceed len_requested.
+  /// @retval true if the buffer has more available data, false otherwise
+  bool get_chunk(uint16_t len_requested, uint8_t **data, uint16_t *len);
+
+  /// @brief Marks the chunk returned by ringbuffer_GetChunk as available
+  /// @param consumed The length of the chunk as returned by ringbuffer_GetChunk(..., len)
+  void report_consumption(uint16_t consumed);
+
+  /// @brief Returns the number of uncommited bytes in the ring buffer
+  uint16_t uncommited() const;
+
+  /// @brief Returns the number of commited bytes in the ring buffer
+  uint16_t commited() const;
+
+  /// @brief Discards the uncommited data in the ring buffer
+  void discard();
+
+private:
+  uint8_t *m_buffer;      //!< Pointer to the phisical memory bufer
+  uint16_t m_size;        //!< Size of the memory buffer in bytes
+  uint16_t m_head;        //!< Write position
+  uint16_t m_head_shadow; //!< Shadowed write position for collecting data before committing it
+  uint16_t m_tail;        //!< Read position
+
+  static uint16_t buffer_used(uint16_t size, uint16_t head, uint16_t tail);
+  static uint16_t buffer_free(uint16_t size, uint16_t head, uint16_t tail);
+
+  uint16_t buffer_used() const;
+  uint16_t buffer_free() const;
+};
+
+} //  namespace

components/f1ll/src/ringbuffer.cpp

@@ -0,0 +1,162 @@
+/*
+ * ringbuffer.c
+ *
+ *  Created on: Sep 14, 2021
+ *      Author: Attila Body
+ */
+
+#include <f1ll/ringbuffer.h>
+// #include "macro_utils.h"
+// #include "print_string.h"
+// #include "taskregistry.h"
+
+#include <cstring>
+
+#include <stm32_assert.h>
+
+#define __ASSERT(x) assert_param(x)
+
+namespace f1ll {
+
+ringbuffer::ringbuffer(uint8_t *buffer, uint16_t size)
+    : m_buffer(buffer),
+      m_size(size),
+      m_head(0),
+      m_head_shadow(0),
+      m_tail(0)
+{
+  __ASSERT(handle);
+  __ASSERT(buffer);
+  __ASSERT(buffer_size);
+}
+
+uint16_t buffer_used(uint16_t size, uint16_t head, uint16_t tail)
+{
+  return head >= tail ? head - tail : size - tail + head;
+}
+
+uint16_t buffer_free(uint16_t size, uint16_t head, uint16_t tail)
+{
+  return size - buffer_used(size, head, tail);
+}
+
+uint16_t ringbuffer::buffer_used() const
+{
+  return m_head_shadow >= m_tail ? m_head_shadow - m_tail : m_size - m_tail + m_head_shadow;
+}
+
+uint16_t ringbuffer::buffer_free() const
+{
+  return m_size - buffer_used();
+}
+
+uint16_t ringbuffer::put(uint8_t const *data_buffer, uint16_t len)
+{
+  uint16_t chunk1 = 0;
+  uint16_t chunk2 = 0;
+
+  if (!data_buffer || !len) {
+    return 0;
+  }
+
+  uint16_t max_len = buffer_free(m_size, m_head_shadow, m_tail);
+  len = len < max_len ? len : max_len;
+
+  chunk1 = m_size - m_head_shadow;
+  if (chunk1 >= len) {
+    chunk1 = len;
+  } else {
+    chunk2 = len - chunk1;
+  }
+
+  std::memcpy(m_buffer + m_head_shadow, data_buffer, chunk1);
+  m_head_shadow += chunk1;
+  if (m_head_shadow == m_size) {
+    m_head_shadow = 0;
+  }
+
+  if (chunk2) {
+    std::memcpy(m_buffer, data_buffer + chunk1, chunk2);
+    m_head_shadow += chunk2;
+    if (m_head_shadow == m_size) {
+      m_head_shadow = 0;
+    }
+  }
+
+  return len;
+}
+
+void ringbuffer::commit()
+{
+
+  uint16_t uncommitted = buffer_used(m_size, m_head_shadow, m_head);
+
+  if (!uncommitted) {
+    return;
+  }
+
+  m_head = m_head_shadow;
+}
+
+// void ringbuffe::flush()
+// {
+//   while (handle->m_head != handle->m_tail) {
+//   }
+// }
+
+bool ringbuffer::get_chunk(uint16_t len_requested, uint8_t **data, uint16_t *len)
+{
+  if (!len_requested || !data || !*data || !len) {
+    return false;
+  }
+
+  uint16_t head = m_head;
+  uint16_t tail = m_tail;
+  uint16_t chunk_size = head >= tail ? head - tail : m_size - tail;
+
+  if (!chunk_size) {
+    *len = 0;
+    return false;
+  }
+
+  if (chunk_size > len_requested) {
+    chunk_size = len_requested;
+  }
+  *data = m_buffer + tail;
+  *len = chunk_size;
+
+  tail += chunk_size;
+  if (tail == m_size) {
+    tail = 0;
+  }
+
+  return tail != head;
+}
+
+void ringbuffer::report_consumption(uint16_t consumed)
+{
+  if (!consumed) {
+    return;
+  }
+  m_tail += consumed;
+  if (m_tail == m_size) {
+    m_tail = 0;
+  }
+}
+
+uint16_t ringbuffer::commited()
+{
+  return buffer_used(m_size, m_tail, m_head);
+}
+
+uint16_t ringbuffer::uncommited()
+{
+  return buffer_used(m_size, m_head_shadow, m_head);
+}
+
+void ringbuffer::discard()
+{
+  m_head_shadow = m_head;
+}
+
+} //  namespace