# HG changeset patch
# User Simon Sapin <simon.sapin@octobus.net>
# Date 2021-10-12 13:29:05
# Node ID 0cc0c097216474bdccce3bcc5eaede5d1e648a3a
# Parent  6e01bcd111d26c4c131315888adc9d87b45a4fe4

dirstate-v2: Only convert from SystemTime to Timestamp and not back

Converting from Timestamp back to SystemTime was only used for equality
comparison, but this can also be done on Timestamp values.

Differential Revision: https://phab.mercurial-scm.org/D11631

diff --git a/rust/hg-core/src/dirstate_tree/on_disk.rs b/rust/hg-core/src/dirstate_tree/on_disk.rs
--- a/rust/hg-core/src/dirstate_tree/on_disk.rs
+++ b/rust/hg-core/src/dirstate_tree/on_disk.rs
@@ -15,7 +15,7 @@ use bytes_cast::BytesCast;
 use format_bytes::format_bytes;
 use std::borrow::Cow;
 use std::convert::{TryFrom, TryInto};
-use std::time::{Duration, SystemTime, UNIX_EPOCH};
+use std::time::{SystemTime, UNIX_EPOCH};
 
 /// Added at the start of `.hg/dirstate` when the "v2" format is used.
 /// This a redundant sanity check more than an actual "magic number" since
@@ -462,18 +462,6 @@ impl From<SystemTime> for Timestamp {
     }
 }
 
-impl From<&'_ Timestamp> for SystemTime {
-    fn from(timestamp: &'_ Timestamp) -> Self {
-        let secs = timestamp.seconds.get();
-        let nanos = timestamp.nanoseconds.get();
-        if secs >= 0 {
-            UNIX_EPOCH + Duration::new(secs as u64, nanos)
-        } else {
-            UNIX_EPOCH - Duration::new((-secs) as u64, nanos)
-        }
-    }
-}
-
 fn read_hg_path(
     on_disk: &[u8],
     slice: PathSlice,
diff --git a/rust/hg-core/src/dirstate_tree/status.rs b/rust/hg-core/src/dirstate_tree/status.rs
--- a/rust/hg-core/src/dirstate_tree/status.rs
+++ b/rust/hg-core/src/dirstate_tree/status.rs
@@ -199,7 +199,8 @@ impl<'a, 'tree, 'on_disk> StatusCommon<'
                 // directory eligible for `read_dir` caching.
                 if let Some(meta) = directory_metadata {
                     if let Ok(current_mtime) = meta.modified() {
-                        if current_mtime == cached_mtime.into() {
+                        let current_mtime = Timestamp::from(current_mtime);
+                        if current_mtime == *cached_mtime {
                             // The mtime of that directory has not changed
                             // since then, which means that the results of
                             // `read_dir` should also be unchanged.