[core] Adds acquire and release methods to the ring buffer class (#16277)

esphome/core/ring_buffer.cpp

@@ -37,6 +37,14 @@ std::unique_ptr<RingBuffer> RingBuffer::create(size_t len, MemoryPreference pref
   return rb;
 }
 
+void *RingBuffer::receive_acquire(size_t &length, size_t max_length, TickType_t ticks_to_wait) {
+  length = 0;
+  void *buffer_data = xRingbufferReceiveUpTo(this->handle_, &length, ticks_to_wait, max_length);
+  return buffer_data;
+}
+
+void RingBuffer::receive_release(void *item) { vRingbufferReturnItem(this->handle_, item); }
+
 size_t RingBuffer::read(void *data, size_t len, TickType_t ticks_to_wait) {
   size_t bytes_read = 0;
 

esphome/core/ring_buffer.h

@@ -27,6 +27,28 @@ class RingBuffer {
    */
   size_t read(void *data, size_t len, TickType_t ticks_to_wait = 0);
 
+  /**
+   * @brief Acquires a pointer into the ring buffer's internal storage without copying.
+   *
+   * The returned pointer is valid until receive_release() is called. Only one item
+   * may be checked out at a time.
+   *
+   * @param[out] length Set to the number of bytes actually acquired (may be less than max_length at wrap boundary)
+   * @param max_length Maximum number of bytes to acquire
+   * @param ticks_to_wait Maximum number of FreeRTOS ticks to wait (default: 0)
+   * @return Pointer into the ring buffer's internal storage, or nullptr if no data is available
+   */
+  void *receive_acquire(size_t &length, size_t max_length, TickType_t ticks_to_wait = 0);
+
+  /**
+   * @brief Releases a previously acquired ring buffer item.
+   *
+   * Must be called exactly once for each successful receive_acquire().
+   *
+   * @param item Pointer returned by receive_acquire()
+   */
+  void receive_release(void *item);
+
   /**
    * @brief Writes to the ring buffer, overwriting oldest data if necessary.
    *