Merge pull request #398 from weibocom/uuid

减少对比次数
weibocom · Nov 29, 2023 · b4fec94 · b4fec94
2 parents 37ec8d9 + 52db15f
commit b4fec94
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Showing 3 changed files with 35 additions and 2 deletions.
diff --git a/protocol/src/uuid/mod.rs b/protocol/src/uuid/mod.rs
@@ -2,6 +2,7 @@ use crate::{
     Command, Commander, Error, Flag, HashedCommand, Metric, MetricItem, Protocol, RequestProcessor,
     Result, Stream, Writer,
 };
+use ds::ByteOrder;
 use sharding::hash::Hash;
 
 #[derive(Clone, Default)]
@@ -36,7 +37,8 @@ impl Protocol for Uuid {
                 return Ok(None);
             }
         }
-        if !data.start_with(0, b"VALUE") {
+        //等价于if !data.start_with(0, b"VALU")，但更快，用于判断响应是否乱序
+        if data.u32_le(0) != u32::from_le_bytes(*b"VALU") {
             return Err(crate::Error::UnexpectedData);
         }
         return Ok(Some(Command::from_ok(stream.take(oft))));

diff --git a/tests/src/benches/criterion.rs b/tests/src/benches/criterion.rs
@@ -19,7 +19,8 @@ criterion_group!(
     ring_slice,
     ring_slice::bench_iter,
     ring_slice::bench_copy,
-    ring_slice::bench_read_num
+    ring_slice::bench_read_num,
+    ring_slice::bench_read_num_vs_start_with
 );
 criterion_group!(arena, arena::bench_alloc);
 

diff --git a/tests/src/benches/ring_slice.rs b/tests/src/benches/ring_slice.rs
@@ -247,3 +247,33 @@ pub(super) fn bench_copy(c: &mut Criterion) {
     });
     group.finish();
 }
+
+pub(super) fn bench_read_num_vs_start_with(c: &mut Criterion) {
+    let mut group = c.benchmark_group("ring_slice_read_num_vs_start_with");
+    let s = b"1VALUE uuid 16784738294\r\njfdjk;afjkd;safjkds;ajfkdsa;".to_vec();
+    let runs = s.len() - 4;
+    let rs = RingSlice::from_vec(&s);
+    group.bench_function("read_num", |b| {
+        b.iter(|| {
+            black_box({
+                let mut v = 0;
+                for i in 0..runs {
+                    v += (rs.u32_le(i) != u32::from_le_bytes(*b"VALU")) as u64;
+                }
+                v
+            });
+        })
+    });
+    group.bench_function("start_with", |b| {
+        b.iter(|| {
+            black_box({
+                let mut v = 0;
+                for i in 0..runs {
+                    v += !rs.start_with(i, b"VALU") as u64;
+                }
+                v
+            });
+        })
+    });
+    group.finish();
+}