1 files changed, 29 insertions, 3 deletions
diff --git a/vendor/fastrand/src/lib.rs b/vendor/fastrand/src/lib.rs
index e6f93233a..3f3ec3d9f 100644
--- a/vendor/fastrand/src/lib.rs
+++ b/vendor/fastrand/src/lib.rs
@@ -70,13 +70,14 @@
 
 use std::cell::Cell;
 use std::collections::hash_map::DefaultHasher;
+use std::convert::TryInto;
 use std::hash::{Hash, Hasher};
 use std::ops::{Bound, RangeBounds};
 use std::thread;
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", not(target_os = "wasi")))]
 use instant::Instant;
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"))))]
 use std::time::Instant;
 
 /// A random number generator.
@@ -281,6 +282,7 @@ impl Rng {
 
     /// Creates a new random number generator with the initial seed.
     #[inline]
+    #[must_use = "this creates a new instance of `Rng`; if you want to initialize the thread-local generator, use `fastrand::seed()` instead"]
     pub fn with_seed(seed: u64) -> Self {
         let rng = Rng(Cell::new(0));
 
@@ -441,6 +443,30 @@ impl Rng {
         }
     }
 
+    /// Fill a byte slice with random data.
+    #[inline]
+    pub fn fill(&self, slice: &mut [u8]) {
+        // We fill the slice by chunks of 8 bytes, or one block of
+        // WyRand output per new state.
+        let mut chunks = slice.chunks_exact_mut(core::mem::size_of::<u64>());
+        for chunk in chunks.by_ref() {
+            let n = self.gen_u64().to_ne_bytes();
+            // Safe because the chunks are always 8 bytes exactly.
+            chunk.copy_from_slice(&n);
+        }
+
+        let remainder = chunks.into_remainder();
+
+        // Any remainder will always be less than 8 bytes.
+        if !remainder.is_empty() {
+            // Generate one last block of 8 bytes of entropy
+            let n = self.gen_u64().to_ne_bytes();
+
+            // Use the remaining length to copy from block
+            remainder.copy_from_slice(&n[..remainder.len()]);
+        }
+    }
+
     rng_integer!(
         u8,
         u8,
@@ -528,7 +554,7 @@ impl Rng {
     /// Panics if the range is empty.
     #[inline]
     pub fn char(&self, range: impl RangeBounds<char>) -> char {
-        use std::convert::{TryFrom, TryInto};
+        use std::convert::TryFrom;
 
         let panic_empty_range = || {
             panic!(