src: simplify size() == 0 checks

PR-URL: #53440
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>

src/blob_serializer_deserializer-inl.h

@@ -247,7 +247,7 @@ size_t BlobSerializer<Impl>::WriteVector(const std::vector<T>& data) {
   }
 
   size_t written_total = WriteArithmetic<size_t>(data.size());
-  if (data.size() == 0) {
+  if (data.empty()) {
     return written_total;
   }
 

src/crypto/crypto_aes.cc

@@ -134,7 +134,7 @@ WebCryptoCipherStatus AES_Cipher(
   //
   // Refs: https://github.com/openssl/openssl/commit/420cb707b880e4fb649094241371701013eeb15f
   // Refs: https://github.com/nodejs/node/pull/38913#issuecomment-866505244
-  if (in.size() == 0) {
+  if (in.empty()) {
     out_len = 0;
   } else if (!EVP_CipherUpdate(ctx.get(),
                                buf.data<unsigned char>(),

src/crypto/crypto_ec.cc

@@ -398,8 +398,7 @@ void ECDH::ConvertKey(const FunctionCallbackInfo<Value>& args) {
   ArrayBufferOrViewContents<char> args0(args[0]);
   if (UNLIKELY(!args0.CheckSizeInt32()))
     return THROW_ERR_OUT_OF_RANGE(env, "key is too big");
-  if (args0.size() == 0)
-    return args.GetReturnValue().SetEmptyString();
+  if (args0.empty()) return args.GetReturnValue().SetEmptyString();
 
   node::Utf8Value curve(env->isolate(), args[1]);
 

src/crypto/crypto_spkac.cc

@@ -39,8 +39,7 @@ bool VerifySpkac(const ArrayBufferOrViewContents<char>& input) {
 void VerifySpkac(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   ArrayBufferOrViewContents<char> input(args[0]);
-  if (input.size() == 0)
-    return args.GetReturnValue().SetEmptyString();
+  if (input.empty()) return args.GetReturnValue().SetEmptyString();
 
   if (UNLIKELY(!input.CheckSizeInt32()))
     return THROW_ERR_OUT_OF_RANGE(env, "spkac is too large");
@@ -76,7 +75,7 @@ void ExportPublicKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
   ArrayBufferOrViewContents<char> input(args[0]);
-  if (input.size() == 0) return args.GetReturnValue().SetEmptyString();
+  if (input.empty()) return args.GetReturnValue().SetEmptyString();
 
   if (UNLIKELY(!input.CheckSizeInt32()))
     return THROW_ERR_OUT_OF_RANGE(env, "spkac is too large");
@@ -109,8 +108,7 @@ void ExportChallenge(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
   ArrayBufferOrViewContents<char> input(args[0]);
-  if (input.size() == 0)
-    return args.GetReturnValue().SetEmptyString();
+  if (input.empty()) return args.GetReturnValue().SetEmptyString();
 
   if (UNLIKELY(!input.CheckSizeInt32()))
     return THROW_ERR_OUT_OF_RANGE(env, "spkac is too large");

src/crypto/crypto_util.h

@@ -233,6 +233,9 @@ class ByteSource {
     // Returns the (allocated) size in bytes.
     size_t size() const { return size_; }
 
+    // Returns if (allocated) size is zero.
+    bool empty() const { return size_ == 0; }
+
     // Finalizes the Builder and returns a read-only view that is optionally
     // truncated.
     ByteSource release(std::optional<size_t> resize = std::nullopt) && {
@@ -271,6 +274,8 @@ class ByteSource {
 
   size_t size() const { return size_; }
 
+  bool empty() const { return size_ == 0; }
+
   operator bool() const { return data_ != nullptr; }
 
   BignumPointer ToBN() const {
@@ -718,22 +723,22 @@ class ArrayBufferOrViewContents {
     // Ideally, these would return nullptr if IsEmpty() or length_ is zero,
     // but some of the openssl API react badly if given a nullptr even when
     // length is zero, so we have to return something.
-    if (size() == 0)
-      return &buf;
+    if (empty()) return &buf;
     return reinterpret_cast<T*>(data_) + offset_;
   }
 
   inline T* data() {
     // Ideally, these would return nullptr if IsEmpty() or length_ is zero,
     // but some of the openssl API react badly if given a nullptr even when
     // length is zero, so we have to return something.
-    if (size() == 0)
-      return &buf;
+    if (empty()) return &buf;
     return reinterpret_cast<T*>(data_) + offset_;
   }
 
   inline size_t size() const { return length_; }
 
+  inline bool empty() const { return length_ == 0; }
+
   // In most cases, input buffer sizes passed in to openssl need to
   // be limited to <= INT_MAX. This utility method helps us check.
   inline bool CheckSizeInt32() { return size() <= INT_MAX; }
@@ -743,14 +748,14 @@ class ArrayBufferOrViewContents {
   }
 
   inline ByteSource ToCopy() const {
-    if (size() == 0) return ByteSource();
+    if (empty()) return ByteSource();
     ByteSource::Builder buf(size());
     memcpy(buf.data<void>(), data(), size());
     return std::move(buf).release();
   }
 
   inline ByteSource ToNullTerminatedCopy() const {
-    if (size() == 0) return ByteSource();
+    if (empty()) return ByteSource();
     ByteSource::Builder buf(size() + 1);
     memcpy(buf.data<void>(), data(), size());
     buf.data<char>()[size()] = 0;

src/module_wrap.cc

@@ -125,7 +125,7 @@ v8::Maybe<bool> ModuleWrap::CheckUnsettledTopLevelAwait() {
 
   auto stalled_messages =
       std::get<1>(module->GetStalledTopLevelAwaitMessages(isolate));
-  if (stalled_messages.size() == 0) {
+  if (stalled_messages.empty()) {
     return v8::Just(true);
   }
 

src/node_file.cc

@@ -1580,7 +1580,7 @@ int MKDirpSync(uv_loop_t* loop,
         // ~FSReqWrapSync():
         case 0:
           req_wrap->continuation_data()->MaybeSetFirstPath(next_path);
-          if (req_wrap->continuation_data()->paths().size() == 0) {
+          if (req_wrap->continuation_data()->paths().empty()) {
             return 0;
           }
           break;
@@ -1596,7 +1596,7 @@ int MKDirpSync(uv_loop_t* loop,
           if (dirname != next_path) {
             req_wrap->continuation_data()->PushPath(std::move(next_path));
             req_wrap->continuation_data()->PushPath(std::move(dirname));
-          } else if (req_wrap->continuation_data()->paths().size() == 0) {
+          } else if (req_wrap->continuation_data()->paths().empty()) {
             err = UV_EEXIST;
             continue;
           }
@@ -1653,7 +1653,7 @@ int MKDirpAsync(uv_loop_t* loop,
         // Note: uv_fs_req_cleanup in terminal paths will be called by
         // FSReqAfterScope::~FSReqAfterScope()
         case 0: {
-          if (req_wrap->continuation_data()->paths().size() == 0) {
+          if (req_wrap->continuation_data()->paths().empty()) {
             req_wrap->continuation_data()->MaybeSetFirstPath(path);
             req_wrap->continuation_data()->Done(0);
           } else {
@@ -1676,7 +1676,7 @@ int MKDirpAsync(uv_loop_t* loop,
           if (dirname != path) {
             req_wrap->continuation_data()->PushPath(path);
             req_wrap->continuation_data()->PushPath(std::move(dirname));
-          } else if (req_wrap->continuation_data()->paths().size() == 0) {
+          } else if (req_wrap->continuation_data()->paths().empty()) {
             err = UV_EEXIST;
             continue;
           }

src/permission/fs_permission.cc

@@ -177,7 +177,7 @@ FSPermission::RadixTree::~RadixTree() {
 bool FSPermission::RadixTree::Lookup(const std::string_view& s,
                                      bool when_empty_return) const {
   FSPermission::RadixTree::Node* current_node = root_node_;
-  if (current_node->children.size() == 0) {
+  if (current_node->children.empty()) {
     return when_empty_return;
   }
   size_t parent_node_prefix_len = current_node->prefix.length();

src/permission/fs_permission.h

@@ -129,7 +129,7 @@ class FSPermission final : public PermissionBase {
       // ---> er
       // ---> n
       bool IsEndNode() const {
-        if (children.size() == 0) {
+        if (children.empty()) {
           return true;
         }
         return is_leaf;