Merge pull request #761 from uuid-rs/chore/bulk-example

Add an example of generating bulk v7 UUIDs

benches/v7.rs

@@ -2,10 +2,44 @@
 #![feature(test)]
 extern crate test;
 
+use std::time::SystemTime;
+
 use test::Bencher;
-use uuid::Uuid;
+use uuid::{ContextV7, NoContext, Timestamp, Uuid};
 
 #[bench]
 fn now_v7(b: &mut Bencher) {
     b.iter(|| Uuid::now_v7());
 }
+
+#[bench]
+fn new_v7_no_context(b: &mut Bencher) {
+    b.iter(|| Uuid::new_v7(Timestamp::now(NoContext)));
+}
+
+#[bench]
+fn new_v7_context(b: &mut Bencher) {
+    let ctxt = ContextV7::new();
+
+    b.iter(|| Uuid::new_v7(Timestamp::now(&ctxt)));
+}
+
+#[bench]
+fn v7_raw(b: &mut Bencher) {
+    let now = SystemTime::UNIX_EPOCH.elapsed().unwrap();
+    let secs = now.as_secs();
+    let subsec_nanos = now.subsec_nanos();
+    let mut counter = 0;
+
+    b.iter(|| {
+        Uuid::new_v7(Timestamp::from_unix_time(
+            secs,
+            subsec_nanos,
+            {
+                counter += 1;
+                counter
+            },
+            42,
+        ))
+    });
+}

examples/Cargo.toml

@@ -12,6 +12,10 @@ path = "src/random_uuid.rs"
 name = "sortable_uuid"
 path = "src/sortable_uuid.rs"
 
+[[example]]
+name = "sortable_uuid_bulk"
+path = "src/sortable_uuid_bulk.rs"
+
 [[example]]
 name = "uuid_macro"
 path = "src/uuid_macro.rs"

examples/src/sortable_uuid_bulk.rs

@@ -0,0 +1,15 @@
+//! Generating a sortable UUID.
+//!
+//! If you enable the `v7` feature you can generate sortable UUIDs.
+//! This example avoids the synchronization cost of `Uuid::now_v7()`
+//! when generating UUIDs in bulk.
+
+fn main() {
+    use uuid::{ContextV7, Timestamp, Uuid};
+
+    let ctxt = ContextV7::new();
+
+    for _ in 0..10 {
+        println!("{}", Uuid::new_v7(Timestamp::now(&ctxt)));
+    }
+}