Merge pull request #6 from MyK00L/convertions

Created convert crate

Cargo.toml

@@ -1,2 +1,2 @@
 [workspace]
-members = ["protos", "contest_service", "rpctest-client", "rpctest-server"]
+members = ["protos", "contest_service", "rpctest-client", "rpctest-server", "convert"]

contest_service/Dockerfile

@@ -1,6 +1,7 @@
 FROM rustlang/rust:nightly as base
 WORKDIR /src
 COPY protos protos
+COPY convert convert
 WORKDIR /src/server
 COPY contest_service/dummy.rs .
 COPY contest_service/Cargo.toml .

convert/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "convert"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+prost-types = "0.8"
+bson = "2.0.0-beta.3"

convert/src/lib.rs

@@ -0,0 +1,8 @@
+#![feature(duration_constants)]
+
+//! Convertion utilities between protobuf and mongodb
+pub mod mongo;
+//pub mod proto;
+
+#[cfg(test)]
+mod tests;

convert/src/mongo.rs

@@ -0,0 +1,14 @@
+/// Convert MongoDB timestamps to Rust's SystemTime
+pub fn timestamp_to_systime(ts: bson::Timestamp) -> std::time::SystemTime {
+    std::time::UNIX_EPOCH + std::time::Duration::from_secs(ts.time.into())
+}
+
+/// Convert a SystemTime to a MongoDB timestamp. Note that MongoDB stores unix timestamps in 32 bits
+pub fn systime_to_timestamp(st: std::time::SystemTime) -> bson::Timestamp {
+    let nano_duration = st.duration_since(std::time::UNIX_EPOCH).unwrap().as_nanos();
+    let seconds = (nano_duration / std::time::Duration::SECOND.as_nanos()) as u32; // This will overflow in 2106
+    bson::Timestamp {
+        time: seconds,
+        increment: 0,
+    }
+}

convert/src/tests.rs

@@ -0,0 +1,37 @@
+use super::*;
+
+fn get_test_time() -> std::time::SystemTime {
+    std::time::UNIX_EPOCH
+        + std::time::Duration::from_secs(10)
+        + std::time::Duration::from_nanos(101)
+}
+#[test]
+fn convert_to_mongo_timestamp_and_back_test() {
+    let now = std::time::UNIX_EPOCH
+        + std::time::Duration::from_secs(
+            std::time::SystemTime::now()
+                .duration_since(std::time::UNIX_EPOCH)
+                .unwrap()
+                .as_secs(),
+        ); //This is needed because we need to discard anything below the second
+    let mongo_now = mongo::systime_to_timestamp(now);
+    assert_eq!(now, mongo::timestamp_to_systime(mongo_now));
+}
+
+#[test]
+fn convert_to_mongo_timestamp_test() {
+    let test_time = get_test_time();
+    let mongo_test_time = mongo::systime_to_timestamp(test_time);
+    assert_eq!(mongo_test_time.time, 10);
+    assert_eq!(mongo_test_time.increment, 0);
+}
+
+#[test]
+fn convert_from_mongo_timestamp_test() {
+    let test_time = get_test_time() - std::time::Duration::from_nanos(101);
+    let mongo_test_time = bson::Timestamp {
+        time: 10,
+        increment: 0,
+    };
+    assert_eq!(mongo::timestamp_to_systime(mongo_test_time), test_time);
+}