Repo created

TMessagesProj/jni/voip/webrtc/absl/strings/internal/memutil.cc

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+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/memutil.h"
+
+#include <cstdlib>
+
+#include "absl/strings/ascii.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace strings_internal {
+
+int memcasecmp(const char* s1, const char* s2, size_t len) {
+  const unsigned char* us1 = reinterpret_cast<const unsigned char*>(s1);
+  const unsigned char* us2 = reinterpret_cast<const unsigned char*>(s2);
+
+  for (size_t i = 0; i < len; i++) {
+    unsigned char c1 = us1[i];
+    unsigned char c2 = us2[i];
+    // If bytes are the same, they will be the same when converted to lower.
+    // So we only need to convert if bytes are not equal.
+    // NOTE(b/308193381): We do not use `absl::ascii_tolower` here in order
+    // to avoid its lookup table and improve performance.
+    if (c1 != c2) {
+      c1 = c1 >= 'A' && c1 <= 'Z' ? c1 - 'A' + 'a' : c1;
+      c2 = c2 >= 'A' && c2 <= 'Z' ? c2 - 'A' + 'a' : c2;
+      const int diff = int{c1} - int{c2};
+      if (diff != 0) return diff;
+    }
+  }
+  return 0;
+}
+
+}  // namespace strings_internal
+ABSL_NAMESPACE_END
+}  // namespace absl