// Copyright 2015 MaidSafe.net limited.
//
// This SAFE Network Software is licensed to you under (1) the MaidSafe.net Commercial License,
// version 1.0 or later, or (2) The General Public License (GPL), version 3, depending on which
// licence you accepted on initial access to the Software (the "Licences").
//
// By contributing code to the SAFE Network Software, or to this project generally, you agree to be
// bound by the terms of the MaidSafe Contributor Agreement. This, along with the Licenses can be
// found in the root directory of this project at LICENSE, COPYING and CONTRIBUTOR.
//
// Unless required by applicable law or agreed to in writing, the SAFE Network Software distributed
// under the GPL Licence is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.
//
// Please review the Licences for the specific language governing permissions and limitations
// relating to use of the SAFE Network Software.
use maidsafe_utilities::event_sender::MaidSafeObserver;
use rand::random;
use xor_name::XorName;
pub type RoutingActionSender = MaidSafeObserver<::action::Action>;
/// Unique ID for messages
///
/// This is used for deduplication: Since the network sends messages redundantly along different
/// routes, the same message will usually arrive more than once at any given node. A message with
/// an ID that is already in the cache will be ignored.
#[derive(Ord, PartialOrd, Debug, Clone, Copy, Eq, PartialEq, RustcEncodable, RustcDecodable, Hash)]
pub struct MessageId(XorName);
impl MessageId {
/// Generate a new `MessageId` with random content.
pub fn new() -> MessageId {
MessageId(random::<XorName>())
}
/// Generate a `MessageId` with value 0. This should only be used for messages where there is
/// no danger of duplication.
pub fn zero() -> MessageId {
MessageId(XorName([0; 32]))
}
/// Generate a new `MessageId` with contents extracted from lost node.
pub fn from_lost_node(mut name: XorName) -> MessageId {
name.0[0] = b'L';
MessageId(name)
}
/// Generate a new `MessageId` with contents extracted from new node.
pub fn from_added_node(mut name: XorName) -> MessageId {
name.0[0] = b'A';
MessageId(name)
}
/// Generate the reverse of the given `MessageId`.
pub fn from_reverse(name: &MessageId) -> MessageId {
let MessageId(XorName(mut name_mut)) = *name;
name_mut.reverse();
MessageId(XorName(name_mut))
}
/// Generate the increment (on the MSB only) of the given `MessageId`.
pub fn increment_first_byte(message_id: &MessageId) -> MessageId {
let MessageId(XorName(mut vec_mut)) = *message_id;
vec_mut[0] = vec_mut[0].wrapping_add(1);
MessageId(XorName(vec_mut))
}
/// Generate the decrement (on the MSB only) of the given `MessageId`.
pub fn decrement_first_byte(message_id: &MessageId) -> MessageId {
let MessageId(XorName(mut vec_mut)) = *message_id;
vec_mut[0] = vec_mut[0].wrapping_sub(1);
MessageId(XorName(vec_mut))
}
}
impl Default for MessageId {
fn default() -> MessageId {
MessageId::zero()
}
}
#[cfg(test)]
#[cfg_attr(feature="cargo-clippy", allow(indexing_slicing))]
mod tests {
use super::MessageId;
use xor_name::{XOR_NAME_LEN, XorName};
#[test]
fn increment() {
let message_id = MessageId::increment_first_byte(&MessageId(XorName([255; XOR_NAME_LEN])));
let MessageId(XorName(vec_bytes)) = message_id;
assert_eq!(vec_bytes[0], 0);
}
#[test]
fn decrement() {
let message_id = MessageId::decrement_first_byte(&MessageId(XorName([0; XOR_NAME_LEN])));
let MessageId(XorName(vec_bytes)) = message_id;
assert_eq!(vec_bytes[0], 255);
}
}