docs(foundationdb): initial commit for documenting Directory

Author: PierreZ

foundationdb/src/directory/directory.rs

@@ -0,0 +1,44 @@
+// Copyright 2018 foundationdb-rs developers, https://github.com/Clikengo/foundationdb-rs/graphs/contributors
+// Copyright 2013-2018 Apple, Inc and the FoundationDB project authors.
+//
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+
+//! Errors that can be thrown by Directory.
+
+use crate::error;
+use crate::tuple::hca::HcaError;
+use std::io;
+
+/// The enumeration holding all possible errors from a Directory.
+#[derive(Debug)]
+pub enum DirectoryError {
+    /// missing path.
+    NoPathProvided,
+    /// tried to create an already existing path.
+    DirAlreadyExists,
+    /// missing path.
+    DirNotExists,
+    /// the layer is incompatible.
+    IncompatibleLayer,
+    Message(String),
+    /// Bad directory version.
+    Version(String),
+    IoError(io::Error),
+    FdbError(error::FdbError),
+    HcaError(HcaError),
+}
+
+impl From<error::FdbError> for DirectoryError {
+    fn from(err: error::FdbError) -> Self {
+        DirectoryError::FdbError(err)
+    }
+}
+
+impl From<HcaError> for DirectoryError {
+    fn from(err: HcaError) -> Self {
+        DirectoryError::HcaError(err)
+    }
+}