1 files changed, 84 insertions, 0 deletions
diff --git a/devices/src/virtio/video/error.rs b/devices/src/virtio/video/error.rs
new file mode 100644
index 0000000..1709306
--- /dev/null
+++ b/devices/src/virtio/video/error.rs
@@ -0,0 +1,84 @@
+// Copyright 2020 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+//! Errors that can happen while encoding or decoding.
+
+use std::fmt;
+use std::io;
+
+use data_model::Le32;
+
+use crate::virtio::resource_bridge::ResourceBridgeError;
+use crate::virtio::video::protocol::*;
+use crate::virtio::video::response::Response;
+use crate::virtio::Writer;
+
+/// An error indicating something went wrong while encoding or decoding.
+/// Unlike `virtio::video::Error`, `VideoError` is not fatal for `Worker`.
+#[derive(Debug)]
+#[allow(dead_code)]
+pub enum VideoError {
+    /// Invalid argument.
+    InvalidArgument,
+    /// Invalid operation
+    InvalidOperation,
+    /// Invalid stream ID is specified.
+    InvalidStreamId(u32),
+    /// Invalid resource ID is specified.
+    InvalidResourceId { stream_id: u32, resource_id: u32 },
+    /// Invalid parameters are specified.
+    InvalidParameter,
+    /// Failed to get a resource FD via resource_bridge.
+    ResourceBridgeFailure(ResourceBridgeError),
+    /// `libvda` returned an error.
+    VdaError(libvda::Error),
+    /// `libvda` returned a failure response.
+    VdaFailure(libvda::Response),
+}
+
+impl fmt::Display for VideoError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use self::VideoError::*;
+        match self {
+            InvalidArgument => write!(f, "invalid argument"),
+            InvalidOperation => write!(f, "invalid operation"),
+            InvalidStreamId(id) => write!(f, "invalid stream ID {}", id),
+            InvalidResourceId {
+                stream_id,
+                resource_id,
+            } => write!(
+                f,
+                "invalid resource ID {} for stream {}",
+                resource_id, stream_id
+            ),
+            InvalidParameter => write!(f, "invalid parameter"),
+            ResourceBridgeFailure(id) => write!(f, "failed to get resource FD for id {}", id),
+            VdaError(e) => write!(f, "error occurred in libvda: {}", e),
+            VdaFailure(r) => write!(f, "failed while processing a requst in VDA: {}", r),
+        }
+    }
+}
+
+impl std::error::Error for VideoError {}
+
+pub type VideoResult<T> = Result<T, VideoError>;
+
+impl Response for VideoError {
+    fn write(&self, w: &mut Writer) -> Result<(), io::Error> {
+        use VideoError::*;
+
+        let type_ = Le32::from(match *self {
+            InvalidResourceId { .. } => VIRTIO_VIDEO_RESP_ERR_INVALID_RESOURCE_ID,
+            InvalidStreamId(_) => VIRTIO_VIDEO_RESP_ERR_INVALID_STREAM_ID,
+            InvalidParameter => VIRTIO_VIDEO_RESP_ERR_INVALID_PARAMETER,
+            // TODO(b/1518105): Add more detailed error code if a new protocol supports ones.
+            _ => VIRTIO_VIDEO_RESP_ERR_INVALID_OPERATION,
+        });
+
+        w.write_obj(virtio_video_cmd_hdr {
+            type_,
+            ..Default::default()
+        })
+    }
+}