buffer: make compare/equals faster

This patch adds a V8 fast API implementation for the buffer.compare binding, which is used both by Buffer.prototype.equals and Buffer.prototype.compare. In particular, it significantly improves the performance of comparing buffers for equality. PR-URL: nodejs#52993 Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Mohammed Keyvanzadeh <[email protected]>
RafaelGSS · May 16, 2024 · 075853e · 075853e
1 parent 3f3226c
commit 075853e
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Showing 2 changed files with 26 additions and 1 deletion.
diff --git a/src/node_buffer.cc b/src/node_buffer.cc
@@ -57,6 +57,7 @@ using v8::ArrayBufferView;
 using v8::BackingStore;
 using v8::Context;
 using v8::EscapableHandleScope;
+using v8::FastApiTypedArray;
 using v8::FunctionCallbackInfo;
 using v8::Global;
 using v8::HandleScope;
@@ -843,6 +844,23 @@ void Compare(const FunctionCallbackInfo<Value> &args) {
   args.GetReturnValue().Set(val);
 }
 
+int32_t FastCompare(v8::Local<v8::Value>,
+                    const FastApiTypedArray<uint8_t>& a,
+                    const FastApiTypedArray<uint8_t>& b) {
+  uint8_t* data_a;
+  uint8_t* data_b;
+  CHECK(a.getStorageIfAligned(&data_a));
+  CHECK(b.getStorageIfAligned(&data_b));
+
+  size_t cmp_length = std::min(a.length(), b.length());
+
+  return normalizeCompareVal(
+      cmp_length > 0 ? memcmp(data_a, data_b, cmp_length) : 0,
+      a.length(),
+      b.length());
+}
+
+static v8::CFunction fast_compare(v8::CFunction::Make(FastCompare));
 
 // Computes the offset for starting an indexOf or lastIndexOf search.
 // Returns either a valid offset in [0...<length - 1>], ie inside the Buffer,
@@ -1409,7 +1427,7 @@ void Initialize(Local<Object> target,
                             SlowByteLengthUtf8,
                             &fast_byte_length_utf8);
   SetMethod(context, target, "copy", Copy);
-  SetMethodNoSideEffect(context, target, "compare", Compare);
+  SetFastMethodNoSideEffect(context, target, "compare", Compare, &fast_compare);
   SetMethodNoSideEffect(context, target, "compareOffset", CompareOffset);
   SetMethod(context, target, "fill", Fill);
   SetMethodNoSideEffect(context, target, "indexOfBuffer", IndexOfBuffer);
@@ -1469,6 +1487,8 @@ void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
   registry->Register(FastByteLengthUtf8);
   registry->Register(Copy);
   registry->Register(Compare);
+  registry->Register(FastCompare);
+  registry->Register(fast_compare.GetTypeInfo());
   registry->Register(CompareOffset);
   registry->Register(Fill);
   registry->Register(IndexOfBuffer);

diff --git a/src/node_external_reference.h b/src/node_external_reference.h
@@ -27,6 +27,10 @@ using CFunctionCallbackWithStrings =
     bool (*)(v8::Local<v8::Value>,
              const v8::FastOneByteString& input,
              const v8::FastOneByteString& base);
+using CFunctionCallbackWithTwoUint8Arrays =
+    int32_t (*)(v8::Local<v8::Value>,
+                const v8::FastApiTypedArray<uint8_t>&,
+                const v8::FastApiTypedArray<uint8_t>&);
 using CFunctionCallbackWithTwoUint8ArraysFallback =
     bool (*)(v8::Local<v8::Value>,
              const v8::FastApiTypedArray<uint8_t>&,
@@ -56,6 +60,7 @@ class ExternalReferenceRegistry {
   V(CFunctionCallbackWithBool)                                                 \
   V(CFunctionCallbackWithString)                                               \
   V(CFunctionCallbackWithStrings)                                              \
+  V(CFunctionCallbackWithTwoUint8Arrays)                                       \
   V(CFunctionCallbackWithTwoUint8ArraysFallback)                               \
   V(CFunctionWithUint32)                                                       \
   V(CFunctionWithDoubleReturnDouble)                                           \