1 files changed, 62 insertions, 0 deletions
diff --git a/services/camera/libcameraservice/device3/Camera3StreamInterface.h b/services/camera/libcameraservice/device3/Camera3StreamInterface.h
index ea90dd9..d177b57 100644
--- a/services/camera/libcameraservice/device3/Camera3StreamInterface.h
+++ b/services/camera/libcameraservice/device3/Camera3StreamInterface.h
@@ -89,6 +89,68 @@ class Camera3StreamInterface : public virtual RefBase {
     virtual status_t cancelConfiguration() = 0;
 
     /**
+     * Determine whether the stream has already become in-use (has received
+     * a valid filled buffer), which determines if a stream can still have
+     * prepareNextBuffer called on it.
+     */
+    virtual bool     isUnpreparable() = 0;
+
+    /**
+     * Start stream preparation. May only be called in the CONFIGURED state,
+     * when no valid buffers have yet been returned to this stream.
+     *
+     * If no prepartion is necessary, returns OK and does not transition to
+     * PREPARING state. Otherwise, returns NOT_ENOUGH_DATA and transitions
+     * to PREPARING.
+     *
+     * Returns:
+     *    OK if no more buffers need to be preallocated
+     *    NOT_ENOUGH_DATA if calls to prepareNextBuffer are needed to finish
+     *        buffer pre-allocation, and transitions to the PREPARING state.
+     *    NO_INIT in case of a serious error from the HAL device
+     *    INVALID_OPERATION if called when not in CONFIGURED state, or a
+     *        valid buffer has already been returned to this stream.
+     */
+    virtual status_t startPrepare() = 0;
+
+    /**
+     * Check if the stream is mid-preparing.
+     */
+    virtual bool     isPreparing() const = 0;
+
+    /**
+     * Continue stream buffer preparation by allocating the next
+     * buffer for this stream.  May only be called in the PREPARED state.
+     *
+     * Returns OK and transitions to the CONFIGURED state if all buffers
+     * are allocated after the call concludes. Otherwise returns NOT_ENOUGH_DATA.
+     *
+     * Returns:
+     *    OK if no more buffers need to be preallocated, and transitions
+     *        to the CONFIGURED state.
+     *    NOT_ENOUGH_DATA if more calls to prepareNextBuffer are needed to finish
+     *        buffer pre-allocation.
+     *    NO_INIT in case of a serious error from the HAL device
+     *    INVALID_OPERATION if called when not in CONFIGURED state, or a
+     *        valid buffer has already been returned to this stream.
+     */
+    virtual status_t prepareNextBuffer() = 0;
+
+    /**
+     * Cancel stream preparation early. In case allocation needs to be
+     * stopped, this method transitions the stream back to the CONFIGURED state.
+     * Buffers that have been allocated with prepareNextBuffer remain that way,
+     * but a later use of prepareNextBuffer will require just as many
+     * calls as if the earlier prepare attempt had not existed.
+     *
+     * Returns:
+     *    OK if cancellation succeeded, and transitions to the CONFIGURED state
+     *    INVALID_OPERATION if not in the PREPARING state
+     *    NO_INIT in case of a serious error from the HAL device
+     */
+    virtual status_t cancelPrepare() = 0;
+
+    /**
      * Fill in the camera3_stream_buffer with the next valid buffer for this
      * stream, to hand over to the HAL.
      *