10 files changed, 589 insertions, 0 deletions
diff --git a/third_party/rust/instant/.cargo-checksum.json b/third_party/rust/instant/.cargo-checksum.json
new file mode 100644
index 0000000000..42dbf0c43b
--- /dev/null
+++ b/third_party/rust/instant/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"AUTHORS":"451a1be16acafff0cb0eaedc49b46063cc6ce087d0c36f6d64d67aa93d20e485","CHANGELOGS.md":"bb587c08dd9b1f04cba934a241a99655f9d7e38bc70e4d45feca95efa09bd799","Cargo.toml":"a64c7ab3a5906d2e7360fb30cc23e5042bd7c22aa640e8e47bb3dad1a3dbf8eb","LICENSE":"2510d4cde8c4e13d8c54b9fe2a9d144daf567ec8d02832f1454e7ca2d58cdda6","README.md":"22b54b9f16ad18144f29e50d1b1f16791c5e8f1afee81265bad9b72f6efb8e62","src/lib.rs":"cc4822f1c4ac7926859045608d91e3f855914468039bffb75bc9b455c0950ab3","src/native.rs":"bd4cd1f888b83a9eaf07f640bef51c4f16138ceb427a685d3ab07152eec53d1c","src/wasm.rs":"c17c7bf8a28fee134444201212d1cf62bff49650f297e42367ec1b7aeaddc7c9","tests/wasm.rs":"1b81ff541bec36bac824a7ec41cd15f68d9919c3c7522290aa003fa4c253e840"},"package":"7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"}
+\ No newline at end of file
diff --git a/third_party/rust/instant/AUTHORS b/third_party/rust/instant/AUTHORS
new file mode 100644
index 0000000000..a4432b1681
--- /dev/null
+++ b/third_party/rust/instant/AUTHORS
@@ -0,0 +1,2 @@
+Main developer:
+    * Sébastien Crozet <developer@crozet.re>
+\ No newline at end of file
diff --git a/third_party/rust/instant/CHANGELOGS.md b/third_party/rust/instant/CHANGELOGS.md
new file mode 100644
index 0000000000..092d8aea3a
--- /dev/null
+++ b/third_party/rust/instant/CHANGELOGS.md
@@ -0,0 +1,7 @@
+# v0.1.12
+## Added 
+- Add `SystemTime` which works in both native and WASM environments.
+
+## Modified
+- The `now` function is always available now: there is no need to enable the `now` feature any more. The `now` feature
+  still exists (but doesn’t do anything) for backwards compatibility.
+\ No newline at end of file
diff --git a/third_party/rust/instant/Cargo.toml b/third_party/rust/instant/Cargo.toml
new file mode 100644
index 0000000000..fcd0adff1a
--- /dev/null
+++ b/third_party/rust/instant/Cargo.toml
@@ -0,0 +1,81 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "instant"
+version = "0.1.12"
+authors = ["sebcrozet <developer@crozet.re>"]
+description = "A partial replacement for std::time::Instant that works on WASM too."
+readme = "README.md"
+keywords = ["time", "wasm"]
+license = "BSD-3-Clause"
+repository = "https://github.com/sebcrozet/instant"
+[dependencies.cfg-if]
+version = "1.0"
+[dev-dependencies.wasm-bindgen-test]
+version = "0.3"
+
+[features]
+inaccurate = []
+now = []
+wasm-bindgen = ["js-sys", "wasm-bindgen_rs", "web-sys"]
+[target.asmjs-unknown-emscripten.dependencies.js-sys]
+version = "0.3"
+optional = true
+
+[target.asmjs-unknown-emscripten.dependencies.stdweb]
+version = "0.4"
+optional = true
+
+[target.asmjs-unknown-emscripten.dependencies.wasm-bindgen_rs]
+version = "0.2"
+optional = true
+package = "wasm-bindgen"
+
+[target.asmjs-unknown-emscripten.dependencies.web-sys]
+version = "0.3"
+features = ["Window", "Performance", "PerformanceTiming"]
+optional = true
+[target.wasm32-unknown-emscripten.dependencies.js-sys]
+version = "0.3"
+optional = true
+
+[target.wasm32-unknown-emscripten.dependencies.stdweb]
+version = "0.4"
+optional = true
+
+[target.wasm32-unknown-emscripten.dependencies.wasm-bindgen_rs]
+version = "0.2"
+optional = true
+package = "wasm-bindgen"
+
+[target.wasm32-unknown-emscripten.dependencies.web-sys]
+version = "0.3"
+features = ["Window", "Performance", "PerformanceTiming"]
+optional = true
+[target.wasm32-unknown-unknown.dependencies.js-sys]
+version = "0.3"
+optional = true
+
+[target.wasm32-unknown-unknown.dependencies.stdweb]
+version = "0.4"
+optional = true
+
+[target.wasm32-unknown-unknown.dependencies.wasm-bindgen_rs]
+version = "0.2"
+optional = true
+package = "wasm-bindgen"
+
+[target.wasm32-unknown-unknown.dependencies.web-sys]
+version = "0.3"
+features = ["Window", "Performance", "PerformanceTiming"]
+optional = true
diff --git a/third_party/rust/instant/LICENSE b/third_party/rust/instant/LICENSE
new file mode 100644
index 0000000000..f8062f39a6
--- /dev/null
+++ b/third_party/rust/instant/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2019, Sébastien Crozet
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the author nor the names of its contributors may be used
+   to endorse or promote products derived from this software without specific
+   prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/third_party/rust/instant/README.md b/third_party/rust/instant/README.md
new file mode 100644
index 0000000000..0e35ad656c
--- /dev/null
+++ b/third_party/rust/instant/README.md
@@ -0,0 +1,143 @@
+# Instant
+
+If you call `std::time::Instant::now()` on a WASM platform, it will panic. This crate provides a partial
+replacement for `std::time::Instant` that works on WASM too. This defines the type `instant::Instant` which is:
+
+* A struct emulating the behavior of **std::time::Instant** if you are targeting `wasm32-unknown-unknown` or `wasm32-unknown-asmjs`
+**and** you enabled either the `stdweb` or the `wasm-bindgen` feature. This emulation is based on the javascript `performance.now()` function.
+* A type alias for `std::time::Instant` otherwise.
+
+
+
+Note that even if the **stdweb** or **wasm-bindgen** feature is enabled, this crate will continue to rely on `std::time::Instant`
+as long as you are not targeting wasm32. This allows for portable code that will work on both native and WASM platforms.
+
+This crate also exports the function `instant::now()` which returns a representation of the current time as an `f64`, expressed in milliseconds, in a platform-agnostic way. `instant::now()` will either:
+
+* Call `performance.now()` when compiling for a WASM platform with the features **stdweb** or **wasm-bindgen** enabled, or using a custom javascript function.
+* Return the time elapsed since the *Unix Epoch* on *native*, *non-WASM* platforms.
+
+*Note*: The old feature, `now`, has been deprecated. `instant::now()` is always exported and the `now` feature flag no longer has any effect. It remains listed in `Cargo.toml` to avoid introducing breaking changes and may be removed in future versions.
+
+## Examples
+### Using `instant` for a native platform.
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = "0.1"
+```
+
+_main.rs_:
+```rust
+fn main() {
+    // Will be the same as `std::time::Instant`.
+    let now = instant::Instant::now();
+}
+```
+
+-----
+
+### Using `instant` for a WASM platform.
+This example shows the use of the `stdweb` feature. It would be similar with `wasm-bindgen`.
+
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = { version = "0.1", features = [ "stdweb" ] }
+```
+
+_main.rs_:
+```rust
+fn main() {
+    // Will emulate `std::time::Instant` based on `performance.now()`.
+    let now = instant::Instant::now();
+}
+```
+
+-----
+
+### Using `instant` for a WASM platform where `performance.now()` is not available.
+This example shows the use of the `inaccurate` feature.
+
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = { version = "0.1", features = [ "wasm-bindgen", "inaccurate" ] }
+```
+
+_main.rs_:
+```rust
+fn main() {
+    // Will emulate `std::time::Instant` based on `Date.now()`.
+    let now = instant::Instant::now();
+}
+```
+
+
+-----
+
+### Using `instant` for any platform enabling a feature transitively.
+_Cargo.toml_:
+```toml
+[features]
+stdweb = [ "instant/stdweb" ]
+wasm-bindgen = [ "instant/wasm-bindgen" ]
+
+[dependencies]
+instant = "0.1"
+```
+
+_lib.rs_:
+```rust
+fn my_function() {
+    // Will select the proper implementation depending on the
+    // feature selected by the user.
+    let now = instant::Instant::now();
+}
+```
+
+-----
+
+### Using `instant::now()`
+_Cargo.toml_:
+```toml
+[features]
+stdweb = [ "instant/stdweb" ]
+wasm-bindgen = [ "instant/wasm-bindgen" ]
+
+[dependencies]
+instant = "0.1"
+```
+
+_lib.rs_:
+```rust
+fn my_function() {
+    // Will select the proper implementation depending on the
+    // feature selected by the user.
+    let now_instant = instant::Instant::now();
+    let now_milliseconds = instant::now(); // In milliseconds.
+}
+```
+
+### Using the feature `now` without `stdweb` or `wasm-bindgen`.
+_Cargo.toml_:
+```toml
+[dependencies]
+instant = "0.1"
+```
+
+_lib.rs_:
+```rust
+fn my_function() {
+    // Will use the 'now' javascript implementation.
+    let now_instant = instant::Instant::now();
+    let now_milliseconds = instant::now(); // In milliseconds.
+}
+```
+
+_javascript WASM bindings file_:
+```js
+function now() {
+	return Date.now() / 1000.0;
+}
+```
diff --git a/third_party/rust/instant/src/lib.rs b/third_party/rust/instant/src/lib.rs
new file mode 100644
index 0000000000..00d59e7f16
--- /dev/null
+++ b/third_party/rust/instant/src/lib.rs
@@ -0,0 +1,22 @@
+cfg_if::cfg_if! {
+    if #[cfg(any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        target_arch = "asmjs"
+    ))] {
+        #[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
+        #[macro_use]
+        extern crate stdweb;
+
+        mod wasm;
+        pub use wasm::Instant;
+        pub use crate::wasm::now;
+        pub use wasm::SystemTime;
+    } else {
+        mod native;
+        pub use native::Instant;
+        pub use native::now;
+        pub use native::SystemTime;
+    }
+}
+
+pub use std::time::Duration;
diff --git a/third_party/rust/instant/src/native.rs b/third_party/rust/instant/src/native.rs
new file mode 100644
index 0000000000..37b34f3e8b
--- /dev/null
+++ b/third_party/rust/instant/src/native.rs
@@ -0,0 +1,9 @@
+pub type Instant = std::time::Instant;
+pub type SystemTime = std::time::SystemTime;
+
+/// The current time, expressed in milliseconds since the Unix Epoch.
+pub fn now() -> f64 {
+    std::time::SystemTime::now().duration_since(std::time::SystemTime::UNIX_EPOCH)
+                                .expect("System clock was before 1970.")
+                                .as_secs_f64() * 1000.0
+}
diff --git a/third_party/rust/instant/src/wasm.rs b/third_party/rust/instant/src/wasm.rs
new file mode 100644
index 0000000000..f11b82a703
--- /dev/null
+++ b/third_party/rust/instant/src/wasm.rs
@@ -0,0 +1,240 @@
+use std::cmp::Ordering;
+use std::ops::{Add, AddAssign, Sub, SubAssign};
+use std::time::Duration;
+
+#[derive(Copy, Clone, Debug, PartialEq, PartialOrd, Hash)]
+pub struct Instant(Duration);
+
+impl Ord for Instant {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.partial_cmp(other)
+            .expect("an instant should never be NaN or Inf.")
+    }
+}
+impl Eq for Instant {}
+
+impl Instant {
+    #[inline]
+    pub fn now() -> Self {
+        Instant(duration_from_f64(now()))
+    }
+
+    #[inline]
+    pub fn duration_since(&self, earlier: Instant) -> Duration {
+        assert!(
+            earlier.0 <= self.0,
+            "`earlier` cannot be later than `self`."
+        );
+        self.0 - earlier.0
+    }
+
+    #[inline]
+    pub fn elapsed(&self) -> Duration {
+        Self::now().duration_since(*self)
+    }
+
+    /// Returns `Some(t)` where `t` is the time `self + duration` if `t` can be represented as
+    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[inline]
+    pub fn checked_add(&self, duration: Duration) -> Option<Instant> {
+        self.0.checked_add(duration).map(Instant)
+    }
+
+    /// Returns `Some(t)` where `t` is the time `self - duration` if `t` can be represented as
+    /// `Instant` (which means it's inside the bounds of the underlying data structure), `None`
+    /// otherwise.
+    #[inline]
+    pub fn checked_sub(&self, duration: Duration) -> Option<Instant> {
+        self.0.checked_sub(duration).map(Instant)
+    }
+
+    /// Returns the amount of time elapsed from another instant to this one, or None if that
+    /// instant is later than this one.
+    #[inline]
+    pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration> {
+        if earlier.0 > self.0 {
+            None
+        } else {
+            Some(self.0 - earlier.0)
+        }
+    }
+
+    /// Returns the amount of time elapsed from another instant to this one, or zero duration if
+    /// that instant is later than this one.
+    #[inline]
+    pub fn saturating_duration_since(&self, earlier: Instant) -> Duration {
+        self.checked_duration_since(earlier).unwrap_or_default()
+    }
+}
+
+impl Add<Duration> for Instant {
+    type Output = Self;
+
+    #[inline]
+    fn add(self, rhs: Duration) -> Self {
+        Instant(self.0 + rhs)
+    }
+}
+
+impl AddAssign<Duration> for Instant {
+    #[inline]
+    fn add_assign(&mut self, rhs: Duration) {
+        self.0 += rhs
+    }
+}
+
+impl Sub<Duration> for Instant {
+    type Output = Self;
+
+    #[inline]
+    fn sub(self, rhs: Duration) -> Self {
+        Instant(self.0 - rhs)
+    }
+}
+
+impl Sub<Instant> for Instant {
+    type Output = Duration;
+
+    #[inline]
+    fn sub(self, rhs: Instant) -> Duration {
+        self.duration_since(rhs)
+    }
+}
+
+impl SubAssign<Duration> for Instant {
+    #[inline]
+    fn sub_assign(&mut self, rhs: Duration) {
+        self.0 -= rhs
+    }
+}
+
+fn duration_from_f64(millis: f64) -> Duration {
+    Duration::from_millis(millis.trunc() as u64)
+        + Duration::from_nanos((millis.fract() * 1.0e6) as u64)
+}
+
+#[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
+#[allow(unused_results)] // Needed because the js macro triggers it.
+pub fn now() -> f64 {
+    use stdweb::unstable::TryInto;
+
+    // https://developer.mozilla.org/en-US/docs/Web/API/Performance/now
+    #[cfg(not(feature = "inaccurate"))]
+    let v = js! { return performance.now(); };
+    #[cfg(feature = "inaccurate")]
+    let v = js! { return Date.now(); };
+    v.try_into().unwrap()
+}
+
+#[cfg(feature = "wasm-bindgen")]
+pub fn now() -> f64 {
+    #[cfg(not(feature = "inaccurate"))]
+    let now = {
+        use wasm_bindgen_rs::prelude::*;
+        use wasm_bindgen_rs::JsCast;
+        js_sys::Reflect::get(&js_sys::global(), &JsValue::from_str("performance"))
+            .expect("failed to get performance from global object")
+            .unchecked_into::<web_sys::Performance>()
+            .now()
+    };
+    #[cfg(feature = "inaccurate")]
+    let now = js_sys::Date::now();
+    now
+}
+
+// The JS now function is in a module so it won't have to be renamed
+#[cfg(not(any(feature = "wasm-bindgen", feature = "stdweb")))]
+mod js {
+    extern "C" {
+        #[cfg(not(target_os = "emscripten"))]
+        pub fn now() -> f64;
+        #[cfg(target_os = "emscripten")]
+        pub fn _emscripten_get_now() -> f64;
+    }
+}
+// Make the unsafe extern function "safe" so it can be called like the other 'now' functions
+#[cfg(not(any(feature = "wasm-bindgen", feature = "stdweb")))]
+pub fn now() -> f64 {
+    #[cfg(not(target_os = "emscripten"))]
+    return unsafe { js::now() };
+    #[cfg(target_os = "emscripten")]
+    return unsafe { js::_emscripten_get_now() };
+}
+
+/// Returns the number of millisecods elapsed since January 1, 1970 00:00:00 UTC.
+#[cfg(any(feature = "wasm-bindgen", feature = "stdweb"))]
+fn get_time() -> f64 {
+    #[cfg(feature = "wasm-bindgen")]
+    return js_sys::Date::now();
+    #[cfg(all(feature = "stdweb", not(feature = "wasm-bindgen")))]
+    {
+        let v = js! { return Date.now(); };
+        return v.try_into().unwrap();
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, PartialOrd)]
+pub struct SystemTime(f64);
+
+impl SystemTime {
+    pub const UNIX_EPOCH: SystemTime = SystemTime(0.0);
+
+    pub fn now() -> SystemTime {
+        cfg_if::cfg_if! {
+            if #[cfg(any(feature = "wasm-bindgen", feature = "stdweb"))] {
+                SystemTime(get_time())
+            } else {
+                SystemTime(now())
+            }
+        }
+    }
+
+    pub fn duration_since(&self, earlier: SystemTime) -> Result<Duration, ()> {
+        let dur_ms = self.0 - earlier.0;
+        if dur_ms < 0.0 {
+            return Err(());
+        }
+        Ok(Duration::from_millis(dur_ms as u64))
+    }
+
+    pub fn elapsed(&self) -> Result<Duration, ()> {
+        self.duration_since(SystemTime::now())
+    }
+
+    pub fn checked_add(&self, duration: Duration) -> Option<SystemTime> {
+        Some(*self + duration)
+    }
+
+    pub fn checked_sub(&self, duration: Duration) -> Option<SystemTime> {
+        Some(*self - duration)
+    }
+}
+
+impl Add<Duration> for SystemTime {
+    type Output = SystemTime;
+
+    fn add(self, other: Duration) -> SystemTime {
+        SystemTime(self.0 + other.as_millis() as f64)
+    }
+}
+
+impl Sub<Duration> for SystemTime {
+    type Output = SystemTime;
+
+    fn sub(self, other: Duration) -> SystemTime {
+        SystemTime(self.0 - other.as_millis() as f64)
+    }
+}
+
+impl AddAssign<Duration> for SystemTime {
+    fn add_assign(&mut self, rhs: Duration) {
+        *self = *self + rhs;
+    }
+}
+
+impl SubAssign<Duration> for SystemTime {
+    fn sub_assign(&mut self, rhs: Duration) {
+        *self = *self - rhs;
+    }
+}
diff --git a/third_party/rust/instant/tests/wasm.rs b/third_party/rust/instant/tests/wasm.rs
new file mode 100644
index 0000000000..7dacdc4f9e
--- /dev/null
+++ b/third_party/rust/instant/tests/wasm.rs
@@ -0,0 +1,57 @@
+extern crate wasm_bindgen_test;
+
+use instant::{Instant, SystemTime};
+use std::time::Duration;
+use wasm_bindgen_test::*;
+
+wasm_bindgen_test_configure!(run_in_browser);
+// run these tests using: wasm-pack test --chrome --headless -- --features wasm-bindgen
+
+#[wasm_bindgen_test]
+fn test_instant_now() {
+    let now = Instant::now();
+    #[cfg(feature = "inaccurate")]
+    while now.elapsed().as_millis() == 0 {}
+    #[cfg(not(feature = "inaccurate"))]
+    assert!(now.elapsed().as_nanos() > 0);
+}
+
+#[wasm_bindgen_test]
+fn test_duration() {
+    let now = Instant::now();
+    let one_sec = Duration::from_secs(1);
+    assert!(now.elapsed() < one_sec);
+}
+
+// Duration::new will overflow when you have u64::MAX seconds and one billion nanoseconds.
+// <https://doc.rust-lang.org/std/time/struct.Duration.html#method.new>
+const ONE_BILLION: u32 = 1_000_000_000;
+
+#[wasm_bindgen_test]
+fn test_checked_add() {
+    let now = Instant::now();
+
+    assert!(now.checked_add(Duration::from_millis(1)).is_some());
+    assert_eq!(
+        None,
+        now.checked_add(Duration::new(u64::MAX, ONE_BILLION - 1))
+    );
+}
+
+#[wasm_bindgen_test]
+fn test_checked_sub() {
+    let now = Instant::now();
+
+    assert!(now.checked_sub(Duration::from_millis(1)).is_some());
+    assert!(now
+        .checked_sub(Duration::new(u64::MAX, ONE_BILLION - 1))
+        .is_none());
+}
+
+#[wasm_bindgen_test]
+fn test_system_time() {
+    assert!(SystemTime::UNIX_EPOCH
+        .duration_since(SystemTime::now())
+        .is_err());
+}
+