Part 4: use DateTime for tx_instants.

db/src/lib.rs

@@ -11,12 +11,12 @@
 #[macro_use]
 extern crate error_chain;
 extern crate itertools;
+
 #[macro_use]
 extern crate lazy_static;
 extern crate rusqlite;
-extern crate time;
-
 extern crate tabwriter;
+extern crate time;
 
 #[macro_use]
 extern crate edn;
@@ -24,8 +24,15 @@ extern crate mentat_core;
 extern crate mentat_tx;
 extern crate mentat_tx_parser;
 
-use itertools::Itertools;
 use std::iter::repeat;
+
+use itertools::Itertools;
+
+use mentat_core::{
+    DateTime,
+    UTC,
+};
+
 pub use errors::{Error, ErrorKind, ResultExt, Result};
 
 pub mod db;
@@ -89,10 +96,7 @@ pub fn repeat_values(values_per_tuple: usize, tuples: usize) -> String {
     values
 }
 
-/// Return the current time in milliseconds after the Unix epoch according to the local clock.
-///
-/// Compare `Date.now()` in JavaScript, `System.currentTimeMillis` in Java.
-pub fn now() -> i64 {
-    let now = time::get_time();
-    (now.sec as i64 * 1_000) + (now.nsec as i64 / (1_000_000))
+/// Return the current time as a UTC `DateTime` instance.
+pub fn now() -> DateTime<UTC> {
+    UTC::now()
 }

db/src/tx.rs

@@ -70,10 +70,13 @@ use internal_types::{
     TermWithTempIds,
     TermWithoutTempIds,
     replace_lookup_ref};
+
 use mentat_core::{
+    DateTime,
+    Schema,
+    UTC,
     attribute,
     intern_set,
-    Schema,
 };
 use mentat_tx::entities as entmod;
 use mentat_tx::entities::{
@@ -127,10 +130,7 @@ pub struct Tx<'conn, 'a> {
     tx_id: Entid,
 
     /// The timestamp when the transaction began to be committed.
-    ///
-    /// This is milliseconds after the Unix epoch according to the transactor's local clock.
-    // TODO: :db.type/instant.
-    tx_instant: i64,
+    tx_instant: DateTime<UTC>,
 }
 
 impl<'conn, 'a> Tx<'conn, 'a> {
@@ -140,7 +140,7 @@ impl<'conn, 'a> Tx<'conn, 'a> {
         schema_for_mutation: &'a Schema,
         schema: &'a Schema,
         tx_id: Entid,
-        tx_instant: i64) -> Tx<'conn, 'a> {
+        tx_instant: DateTime<UTC>) -> Tx<'conn, 'a> {
         Tx {
             store: store,
             partition_map: partition_map,
@@ -532,7 +532,7 @@ impl<'conn, 'a> Tx<'conn, 'a> {
         non_fts_one.push((self.tx_id,
                           entids::DB_TX_INSTANT,
                           self.schema.require_attribute_for_entid(entids::DB_TX_INSTANT).unwrap(),
-                          TypedValue::Long(self.tx_instant),
+                          TypedValue::Instant(self.tx_instant),
                           true));
 
         if !non_fts_one.is_empty() {

db/src/types.rs

@@ -16,12 +16,14 @@ use std::collections::BTreeMap;
 extern crate mentat_core;
 
 pub use self::mentat_core::{
+    DateTime,
     Entid,
     ValueType,
     TypedValue,
     Attribute,
     AttributeBitFlags,
     Schema,
+    UTC,
 };
 
 /// Represents one partition of the entid space.
@@ -78,16 +80,13 @@ pub type AVMap<'a> = HashMap<&'a AVPair, Entid>;
 
 /// A transaction report summarizes an applied transaction.
 // TODO: include map of resolved tempids.
-#[derive(Clone, Debug, Default, Eq, Hash, Ord, PartialOrd, PartialEq)]
+#[derive(Clone, Debug, Eq, Hash, Ord, PartialOrd, PartialEq)]
 pub struct TxReport {
     /// The transaction ID of the transaction.
     pub tx_id: Entid,
 
     /// The timestamp when the transaction began to be committed.
-    ///
-    /// This is milliseconds after the Unix epoch according to the transactor's local clock.
-    // TODO: :db.type/instant.
-    pub tx_instant: i64,
+    pub tx_instant: DateTime<UTC>,
 
     /// A map from string literal tempid to resolved or allocated entid.
     ///
@@ -96,3 +95,13 @@ pub struct TxReport {
     /// literal tempids to all unify to a single freshly allocated entid.)
     pub tempids: BTreeMap<String, Entid>,
 }
+
+impl Default for TxReport {
+    fn default() -> Self {
+        TxReport {
+            tx_id: Entid::default(),
+            tx_instant: UTC::now(),
+            tempids: BTreeMap::default(),
+        }
+    }
+}