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-rw-r--r--absl/functional/BUILD.bazel51
-rw-r--r--absl/functional/function_ref.h137
-rw-r--r--absl/functional/function_ref_benchmark.cc140
-rw-r--r--absl/functional/function_ref_test.cc255
-rw-r--r--absl/functional/internal/function_ref.h104
-rw-r--r--absl/strings/BUILD.bazel5
-rw-r--r--absl/strings/CMakeLists.txt2
-rw-r--r--absl/strings/escaping.cc33
-rw-r--r--absl/strings/numbers.cc29
-rw-r--r--absl/strings/numbers.h45
-rw-r--r--absl/strings/numbers_benchmark.cc23
-rw-r--r--absl/strings/numbers_test.cc30
-rw-r--r--absl/strings/str_cat.cc5
-rw-r--r--absl/strings/substitute.cc5
14 files changed, 824 insertions, 40 deletions
diff --git a/absl/functional/BUILD.bazel b/absl/functional/BUILD.bazel
new file mode 100644
index 00000000..e861b8a5
--- /dev/null
+++ b/absl/functional/BUILD.bazel
@@ -0,0 +1,51 @@
+load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
+load(
+ "//absl:copts/configure_copts.bzl",
+ "ABSL_DEFAULT_COPTS",
+ "ABSL_DEFAULT_LINKOPTS",
+ "ABSL_TEST_COPTS",
+)
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"]) # Apache 2.0
+
+cc_library(
+ name = "function_ref",
+ srcs = ["internal/function_ref.h"],
+ hdrs = ["function_ref.h"],
+ copts = ABSL_DEFAULT_COPTS,
+ linkopts = ABSL_DEFAULT_LINKOPTS,
+ deps = [
+ "//absl/base:base_internal",
+ "//absl/meta:type_traits",
+ ],
+)
+
+cc_test(
+ name = "function_ref_test",
+ size = "small",
+ srcs = ["function_ref_test.cc"],
+ copts = ABSL_TEST_COPTS,
+ deps = [
+ ":function_ref",
+ "//absl/container:test_instance_tracker",
+ "//absl/memory",
+ "@com_google_googletest//:gtest_main",
+ ],
+)
+
+cc_test(
+ name = "function_ref_benchmark",
+ srcs = [
+ "function_ref_benchmark.cc",
+ ],
+ copts = ABSL_TEST_COPTS,
+ tags = ["benchmark"],
+ visibility = ["//visibility:private"],
+ deps = [
+ ":function_ref",
+ "//absl/base:core_headers",
+ "@com_github_google_benchmark//:benchmark_main",
+ ],
+)
diff --git a/absl/functional/function_ref.h b/absl/functional/function_ref.h
new file mode 100644
index 00000000..42d9f16f
--- /dev/null
+++ b/absl/functional/function_ref.h
@@ -0,0 +1,137 @@
+// Copyright 2019 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.
+//
+// -----------------------------------------------------------------------------
+// File: function_ref.h
+// -----------------------------------------------------------------------------
+//
+// This header file defines the `absl::FunctionRef` type for holding a
+// non-owning reference to an object of any invocable type. This function
+// reference is typically most useful as a type-erased argument type for
+// accepting function types that neither take ownership nor copy the type; using
+// the reference type in this case avoids a copy and an allocation. Best
+// practices of other non-owning reference-like objects (such as
+// `absl::string_view`) apply here.
+//
+// An `absl::FunctionRef` is similar in usage to a `std::function` but has the
+// following differences:
+//
+// * It doesn't own the underlying object.
+// * It doesn't have a null or empty state.
+// * It never performs deep copies or allocations.
+// * It's much faster and cheaper to construct.
+// * It's trivially copyable and destructable.
+//
+// Generally, `absl::FunctionRef` should not be used as a return value, data
+// member, or to initialize a `std::function`. Such usages will often lead to
+// problematic lifetime issues. Once you convert something to an
+// `absl::FunctionRef` you cannot make a deep copy later.
+//
+// This class is suitable for use wherever a "const std::function<>&"
+// would be used without making a copy. ForEach functions and other versions of
+// the visitor pattern are a good example of when this class should be used.
+//
+// This class is trivial to copy and should be passed by value.
+#ifndef ABSL_FUNCTIONAL_FUNCTION_REF_H_
+#define ABSL_FUNCTIONAL_FUNCTION_REF_H_
+
+#include <cassert>
+#include <functional>
+#include <type_traits>
+
+#include "absl/functional/internal/function_ref.h"
+#include "absl/meta/type_traits.h"
+
+namespace absl {
+
+// FunctionRef
+//
+// Dummy class declaration to allow the partial specialization based on function
+// types below.
+template <typename T>
+class FunctionRef;
+
+// FunctionRef
+//
+// An `absl::FunctionRef` is a lightweight wrapper to any invokable object with
+// a compatible signature. Generally, an `absl::FunctionRef` should only be used
+// as an argument type and should be preferred as an argument over a const
+// reference to a `std::function`.
+//
+// Example:
+//
+// // The following function takes a function callback by const reference
+// bool Visitor(const std::function<void(my_proto&,
+// absl::string_view)>& callback);
+//
+// // Assuming that the function is not stored or otherwise copied, it can be
+// // replaced by an `absl::FunctionRef`:
+// bool Visitor(absl::FunctionRef<void(my_proto&, absl::string_view)>
+// callback);
+//
+// Note: the assignment operator within an `absl::FunctionRef` is intentionally
+// deleted to prevent misuse; because the `absl::FunctionRef` does not own the
+// underlying type, assignment likely indicates misuse.
+template <typename R, typename... Args>
+class FunctionRef<R(Args...)> {
+ private:
+ // Used to disable constructors for objects that are not compatible with the
+ // signature of this FunctionRef.
+ template <typename F,
+ typename FR = absl::base_internal::InvokeT<F, Args&&...>>
+ using EnableIfCompatible =
+ typename std::enable_if<std::is_void<R>::value ||
+ std::is_convertible<FR, R>::value>::type;
+
+ public:
+ // Constructs a FunctionRef from any invokable type.
+ template <typename F, typename = EnableIfCompatible<const F&>>
+ FunctionRef(const F& f) // NOLINT(runtime/explicit)
+ : invoker_(&absl::functional_internal::InvokeObject<F, R, Args...>) {
+ absl::functional_internal::AssertNonNull(f);
+ ptr_.obj = &f;
+ }
+
+ // Overload for function pointers. This eliminates a level of indirection that
+ // would happen if the above overload was used (it lets us store the pointer
+ // instead of a pointer to a pointer).
+ //
+ // This overload is also used for references to functions, since references to
+ // functions can decay to function pointers implicitly.
+ template <
+ typename F, typename = EnableIfCompatible<F*>,
+ absl::functional_internal::EnableIf<absl::is_function<F>::value> = 0>
+ FunctionRef(F* f) // NOLINT(runtime/explicit)
+ : invoker_(&absl::functional_internal::InvokeFunction<F*, R, Args...>) {
+ assert(f != nullptr);
+ ptr_.fun = reinterpret_cast<decltype(ptr_.fun)>(f);
+ }
+
+ // To help prevent subtle lifetime bugs, FunctionRef is not assignable.
+ // Typically, it should only be used as an argument type.
+ FunctionRef& operator=(const FunctionRef& rhs) = delete;
+
+ // Call the underlying object.
+ R operator()(Args... args) const {
+ return invoker_(ptr_, std::forward<Args>(args)...);
+ }
+
+ private:
+ absl::functional_internal::VoidPtr ptr_;
+ absl::functional_internal::Invoker<R, Args...> invoker_;
+};
+
+} // namespace absl
+
+#endif // ABSL_FUNCTIONAL_FUNCTION_REF_H_
diff --git a/absl/functional/function_ref_benchmark.cc b/absl/functional/function_ref_benchmark.cc
new file mode 100644
index 00000000..f6dfcabf
--- /dev/null
+++ b/absl/functional/function_ref_benchmark.cc
@@ -0,0 +1,140 @@
+// Copyright 2019 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/functional/function_ref.h"
+
+#include <memory>
+
+#include "benchmark/benchmark.h"
+#include "absl/base/attributes.h"
+
+namespace absl {
+namespace {
+
+int dummy = 0;
+
+void FreeFunction() { benchmark::DoNotOptimize(dummy); }
+
+struct TrivialFunctor {
+ void operator()() const { benchmark::DoNotOptimize(dummy); }
+};
+
+struct LargeFunctor {
+ void operator()() const { benchmark::DoNotOptimize(this); }
+ std::string a, b, c;
+};
+
+template <typename Function, typename... Args>
+void ABSL_ATTRIBUTE_NOINLINE CallFunction(Function f, Args&&... args) {
+ f(std::forward<Args>(args)...);
+}
+
+template <typename Function, typename Callable, typename... Args>
+void ConstructAndCallFunctionBenchmark(benchmark::State& state,
+ const Callable& c, Args&&... args) {
+ for (auto _ : state) {
+ CallFunction<Function>(c, std::forward<Args>(args)...);
+ }
+}
+
+void BM_TrivialStdFunction(benchmark::State& state) {
+ ConstructAndCallFunctionBenchmark<std::function<void()>>(state,
+ TrivialFunctor{});
+}
+BENCHMARK(BM_TrivialStdFunction);
+
+void BM_TrivialFunctionRef(benchmark::State& state) {
+ ConstructAndCallFunctionBenchmark<FunctionRef<void()>>(state,
+ TrivialFunctor{});
+}
+BENCHMARK(BM_TrivialFunctionRef);
+
+void BM_LargeStdFunction(benchmark::State& state) {
+ ConstructAndCallFunctionBenchmark<std::function<void()>>(state,
+ LargeFunctor{});
+}
+BENCHMARK(BM_LargeStdFunction);
+
+void BM_LargeFunctionRef(benchmark::State& state) {
+ ConstructAndCallFunctionBenchmark<FunctionRef<void()>>(state, LargeFunctor{});
+}
+BENCHMARK(BM_LargeFunctionRef);
+
+void BM_FunPtrStdFunction(benchmark::State& state) {
+ ConstructAndCallFunctionBenchmark<std::function<void()>>(state, FreeFunction);
+}
+BENCHMARK(BM_FunPtrStdFunction);
+
+void BM_FunPtrFunctionRef(benchmark::State& state) {
+ ConstructAndCallFunctionBenchmark<FunctionRef<void()>>(state, FreeFunction);
+}
+BENCHMARK(BM_FunPtrFunctionRef);
+
+// Doesn't include construction or copy overhead in the loop.
+template <typename Function, typename Callable, typename... Args>
+void CallFunctionBenchmark(benchmark::State& state, const Callable& c,
+ Args... args) {
+ Function f = c;
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(&f);
+ f(args...);
+ }
+}
+
+struct FunctorWithTrivialArgs {
+ void operator()(int a, int b, int c) const {
+ benchmark::DoNotOptimize(a);
+ benchmark::DoNotOptimize(b);
+ benchmark::DoNotOptimize(c);
+ }
+};
+
+void BM_TrivialArgsStdFunction(benchmark::State& state) {
+ CallFunctionBenchmark<std::function<void(int, int, int)>>(
+ state, FunctorWithTrivialArgs{}, 1, 2, 3);
+}
+BENCHMARK(BM_TrivialArgsStdFunction);
+
+void BM_TrivialArgsFunctionRef(benchmark::State& state) {
+ CallFunctionBenchmark<FunctionRef<void(int, int, int)>>(
+ state, FunctorWithTrivialArgs{}, 1, 2, 3);
+}
+BENCHMARK(BM_TrivialArgsFunctionRef);
+
+struct FunctorWithNonTrivialArgs {
+ void operator()(std::string a, std::string b, std::string c) const {
+ benchmark::DoNotOptimize(&a);
+ benchmark::DoNotOptimize(&b);
+ benchmark::DoNotOptimize(&c);
+ }
+};
+
+void BM_NonTrivialArgsStdFunction(benchmark::State& state) {
+ std::string a, b, c;
+ CallFunctionBenchmark<
+ std::function<void(std::string, std::string, std::string)>>(
+ state, FunctorWithNonTrivialArgs{}, a, b, c);
+}
+BENCHMARK(BM_NonTrivialArgsStdFunction);
+
+void BM_NonTrivialArgsFunctionRef(benchmark::State& state) {
+ std::string a, b, c;
+ CallFunctionBenchmark<
+ FunctionRef<void(std::string, std::string, std::string)>>(
+ state, FunctorWithNonTrivialArgs{}, a, b, c);
+}
+BENCHMARK(BM_NonTrivialArgsFunctionRef);
+
+} // namespace
+} // namespace absl
diff --git a/absl/functional/function_ref_test.cc b/absl/functional/function_ref_test.cc
new file mode 100644
index 00000000..90829db0
--- /dev/null
+++ b/absl/functional/function_ref_test.cc
@@ -0,0 +1,255 @@
+// Copyright 2019 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/functional/function_ref.h"
+
+#include <memory>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/container/internal/test_instance_tracker.h"
+#include "absl/memory/memory.h"
+
+namespace absl {
+namespace {
+
+void RunFun(FunctionRef<void()> f) { f(); }
+
+TEST(FunctionRefTest, Lambda) {
+ bool ran = false;
+ RunFun([&] { ran = true; });
+ EXPECT_TRUE(ran);
+}
+
+int Function() { return 1337; }
+
+TEST(FunctionRefTest, Function1) {
+ FunctionRef<int()> ref(&Function);
+ EXPECT_EQ(1337, ref());
+}
+
+TEST(FunctionRefTest, Function2) {
+ FunctionRef<int()> ref(Function);
+ EXPECT_EQ(1337, ref());
+}
+
+int NoExceptFunction() noexcept { return 1337; }
+
+// TODO(jdennett): Add a test for noexcept member functions.
+TEST(FunctionRefTest, NoExceptFunction) {
+ FunctionRef<int()> ref(NoExceptFunction);
+ EXPECT_EQ(1337, ref());
+}
+
+TEST(FunctionRefTest, ForwardsArgs) {
+ auto l = [](std::unique_ptr<int> i) { return *i; };
+ FunctionRef<int(std::unique_ptr<int>)> ref(l);
+ EXPECT_EQ(42, ref(absl::make_unique<int>(42)));
+}
+
+TEST(FunctionRef, ReturnMoveOnly) {
+ auto l = [] { return absl::make_unique<int>(29); };
+ FunctionRef<std::unique_ptr<int>()> ref(l);
+ EXPECT_EQ(29, *ref());
+}
+
+TEST(FunctionRef, ManyArgs) {
+ auto l = [](int a, int b, int c) { return a + b + c; };
+ FunctionRef<int(int, int, int)> ref(l);
+ EXPECT_EQ(6, ref(1, 2, 3));
+}
+
+TEST(FunctionRef, VoidResultFromNonVoidFunctor) {
+ bool ran = false;
+ auto l = [&]() -> int {
+ ran = true;
+ return 2;
+ };
+ FunctionRef<void()> ref(l);
+ ref();
+ EXPECT_TRUE(ran);
+}
+
+TEST(FunctionRef, CastFromDerived) {
+ struct Base {};
+ struct Derived : public Base {};
+
+ Derived d;
+ auto l1 = [&](Base* b) { EXPECT_EQ(&d, b); };
+ FunctionRef<void(Derived*)> ref1(l1);
+ ref1(&d);
+
+ auto l2 = [&]() -> Derived* { return &d; };
+ FunctionRef<Base*()> ref2(l2);
+ EXPECT_EQ(&d, ref2());
+}
+
+TEST(FunctionRef, VoidResultFromNonVoidFuncton) {
+ FunctionRef<void()> ref(Function);
+ ref();
+}
+
+TEST(FunctionRef, MemberPtr) {
+ struct S {
+ int i;
+ };
+
+ S s{1100111};
+ auto mem_ptr = &S::i;
+ FunctionRef<int(const S& s)> ref(mem_ptr);
+ EXPECT_EQ(1100111, ref(s));
+}
+
+TEST(FunctionRef, MemberFun) {
+ struct S {
+ int i;
+ int get_i() const { return i; }
+ };
+
+ S s{22};
+ auto mem_fun_ptr = &S::get_i;
+ FunctionRef<int(const S& s)> ref(mem_fun_ptr);
+ EXPECT_EQ(22, ref(s));
+}
+
+TEST(FunctionRef, MemberFunRefqualified) {
+ struct S {
+ int i;
+ int get_i() && { return i; }
+ };
+ auto mem_fun_ptr = &S::get_i;
+ S s{22};
+ FunctionRef<int(S && s)> ref(mem_fun_ptr);
+ EXPECT_EQ(22, ref(std::move(s)));
+}
+
+#if !defined(_WIN32) && defined(GTEST_HAS_DEATH_TEST)
+
+TEST(FunctionRef, MemberFunRefqualifiedNull) {
+ struct S {
+ int i;
+ int get_i() && { return i; }
+ };
+ auto mem_fun_ptr = &S::get_i;
+ mem_fun_ptr = nullptr;
+ EXPECT_DEBUG_DEATH({ FunctionRef<int(S && s)> ref(mem_fun_ptr); }, "");
+}
+
+TEST(FunctionRef, NullMemberPtrAssertFails) {
+ struct S {
+ int i;
+ };
+ using MemberPtr = int S::*;
+ MemberPtr mem_ptr = nullptr;
+ EXPECT_DEBUG_DEATH({ FunctionRef<int(const S& s)> ref(mem_ptr); }, "");
+}
+
+#endif // GTEST_HAS_DEATH_TEST
+
+TEST(FunctionRef, CopiesAndMovesPerPassByValue) {
+ absl::test_internal::InstanceTracker tracker;
+ absl::test_internal::CopyableMovableInstance instance(0);
+ auto l = [](absl::test_internal::CopyableMovableInstance) {};
+ FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
+ ref(instance);
+ EXPECT_EQ(tracker.copies(), 1);
+ EXPECT_EQ(tracker.moves(), 1);
+}
+
+TEST(FunctionRef, CopiesAndMovesPerPassByRef) {
+ absl::test_internal::InstanceTracker tracker;
+ absl::test_internal::CopyableMovableInstance instance(0);
+ auto l = [](const absl::test_internal::CopyableMovableInstance&) {};
+ FunctionRef<void(const absl::test_internal::CopyableMovableInstance&)> ref(l);
+ ref(instance);
+ EXPECT_EQ(tracker.copies(), 0);
+ EXPECT_EQ(tracker.moves(), 0);
+}
+
+TEST(FunctionRef, CopiesAndMovesPerPassByValueCallByMove) {
+ absl::test_internal::InstanceTracker tracker;
+ absl::test_internal::CopyableMovableInstance instance(0);
+ auto l = [](absl::test_internal::CopyableMovableInstance) {};
+ FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
+ ref(std::move(instance));
+ EXPECT_EQ(tracker.copies(), 0);
+ EXPECT_EQ(tracker.moves(), 2);
+}
+
+TEST(FunctionRef, CopiesAndMovesPerPassByValueToRef) {
+ absl::test_internal::InstanceTracker tracker;
+ absl::test_internal::CopyableMovableInstance instance(0);
+ auto l = [](const absl::test_internal::CopyableMovableInstance&) {};
+ FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
+ ref(std::move(instance));
+ EXPECT_EQ(tracker.copies(), 0);
+ EXPECT_EQ(tracker.moves(), 1);
+}
+
+TEST(FunctionRef, PassByValueTypes) {
+ using absl::functional_internal::Invoker;
+ using absl::functional_internal::VoidPtr;
+ using absl::test_internal::CopyableMovableInstance;
+ struct Trivial {
+ void* p[2];
+ };
+ struct LargeTrivial {
+ void* p[3];
+ };
+
+ static_assert(std::is_same<Invoker<void, int>, void (*)(VoidPtr, int)>::value,
+ "Scalar types should be passed by value");
+ static_assert(
+ std::is_same<Invoker<void, Trivial>, void (*)(VoidPtr, Trivial)>::value,
+ "Small trivial types should be passed by value");
+ static_assert(std::is_same<Invoker<void, LargeTrivial>,
+ void (*)(VoidPtr, LargeTrivial &&)>::value,
+ "Large trivial types should be passed by rvalue reference");
+ static_assert(
+ std::is_same<Invoker<void, CopyableMovableInstance>,
+ void (*)(VoidPtr, CopyableMovableInstance &&)>::value,
+ "Types with copy/move ctor should be passed by rvalue reference");
+
+ // References are passed as references.
+ static_assert(
+ std::is_same<Invoker<void, int&>, void (*)(VoidPtr, int&)>::value,
+ "Reference types should be preserved");
+ static_assert(
+ std::is_same<Invoker<void, CopyableMovableInstance&>,
+ void (*)(VoidPtr, CopyableMovableInstance&)>::value,
+ "Reference types should be preserved");
+ static_assert(
+ std::is_same<Invoker<void, CopyableMovableInstance&&>,
+ void (*)(VoidPtr, CopyableMovableInstance &&)>::value,
+ "Reference types should be preserved");
+
+ // Make sure the address of an object received by reference is the same as the
+ // addess of the object passed by the caller.
+ {
+ LargeTrivial obj;
+ auto test = [&obj](LargeTrivial& input) { ASSERT_EQ(&input, &obj); };
+ absl::FunctionRef<void(LargeTrivial&)> ref(test);
+ ref(obj);
+ }
+
+ {
+ Trivial obj;
+ auto test = [&obj](Trivial& input) { ASSERT_EQ(&input, &obj); };
+ absl::FunctionRef<void(Trivial&)> ref(test);
+ ref(obj);
+ }
+}
+
+} // namespace
+} // namespace absl
diff --git a/absl/functional/internal/function_ref.h b/absl/functional/internal/function_ref.h
new file mode 100644
index 00000000..fcb0496c
--- /dev/null
+++ b/absl/functional/internal/function_ref.h
@@ -0,0 +1,104 @@
+// Copyright 2019 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.
+
+#ifndef ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_
+#define ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_
+
+#include <cassert>
+#include <functional>
+#include <type_traits>
+
+#include "absl/base/internal/invoke.h"
+#include "absl/meta/type_traits.h"
+
+namespace absl {
+namespace functional_internal {
+
+// Like a void* that can handle function pointers as well. The standard does not
+// allow function pointers to round-trip through void*, but void(*)() is fine.
+//
+// Note: It's important that this class remains trivial and is the same size as
+// a pointer, since this allows the compiler to perform tail-call optimizations
+// when the underlying function is a callable object with a matching signature.
+union VoidPtr {
+ const void* obj;
+ void (*fun)();
+};
+
+// Chooses the best type for passing T as an argument.
+// Attempt to be close to SystemV AMD64 ABI. Objects with trivial copy ctor are
+// passed by value.
+template <typename T>
+constexpr bool PassByValue() {
+ return !std::is_lvalue_reference<T>::value &&
+ absl::is_trivially_copy_constructible<T>::value &&
+ absl::is_trivially_copy_assignable<
+ typename std::remove_cv<T>::type>::value &&
+ std::is_trivially_destructible<T>::value &&
+ sizeof(T) <= 2 * sizeof(void*);
+}
+
+template <typename T>
+struct ForwardT : std::conditional<PassByValue<T>(), T, T&&> {};
+
+// An Invoker takes a pointer to the type-erased invokable object, followed by
+// the arguments that the invokable object expects.
+//
+// Note: The order of arguments here is an optimization, since member functions
+// have an implicit "this" pointer as their first argument, putting VoidPtr
+// first allows the compiler to perform tail-call optimization in many cases.
+template <typename R, typename... Args>
+using Invoker = R (*)(VoidPtr, typename ForwardT<Args>::type...);
+
+//
+// InvokeObject and InvokeFunction provide static "Invoke" functions that can be
+// used as Invokers for objects or functions respectively.
+//
+// static_cast<R> handles the case the return type is void.
+template <typename Obj, typename R, typename... Args>
+R InvokeObject(VoidPtr ptr, typename ForwardT<Args>::type... args) {
+ auto o = static_cast<const Obj*>(ptr.obj);
+ return static_cast<R>(
+ absl::base_internal::Invoke(*o, std::forward<Args>(args)...));
+}
+
+template <typename Fun, typename R, typename... Args>
+R InvokeFunction(VoidPtr ptr, typename ForwardT<Args>::type... args) {
+ auto f = reinterpret_cast<Fun>(ptr.fun);
+ return static_cast<R>(
+ absl::base_internal::Invoke(f, std::forward<Args>(args)...));
+}
+
+template <typename Sig>
+void AssertNonNull(const std::function<Sig>& f) {
+ assert(f != nullptr);
+ (void)f;
+}
+
+template <typename F>
+void AssertNonNull(const F&) {}
+
+template <typename F, typename C>
+void AssertNonNull(F C::*f) {
+ assert(f != nullptr);
+ (void)f;
+}
+
+template <bool C>
+using EnableIf = typename ::std::enable_if<C, int>::type;
+
+} // namespace functional_internal
+} // namespace absl
+
+#endif // ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_
diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 4863ead2..e38c8ad6 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -413,8 +413,9 @@ cc_test(
deps = [
":pow10_helper",
":strings",
- "//absl/base:core_headers",
"//absl/base:raw_logging_internal",
+ "//absl/random",
+ "//absl/random:distributions",
"@com_google_googletest//:gtest_main",
],
)
@@ -428,6 +429,8 @@ cc_test(
deps = [
":strings",
"//absl/base:raw_logging_internal",
+ "//absl/random",
+ "//absl/random:distributions",
"@com_github_google_benchmark//:benchmark_main",
],
)
diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt
index 3f907957..cd52a472 100644
--- a/absl/strings/CMakeLists.txt
+++ b/absl/strings/CMakeLists.txt
@@ -277,6 +277,8 @@ absl_cc_test(
absl::core_headers
absl::pow10_helper
absl::raw_logging_internal
+ absl::random_random
+ absl::random_distributions
gmock_main
)
diff --git a/absl/strings/escaping.cc b/absl/strings/escaping.cc
index 0d336e3f..88390fbf 100644
--- a/absl/strings/escaping.cc
+++ b/absl/strings/escaping.cc
@@ -35,27 +35,6 @@
namespace absl {
namespace {
-// Digit conversion.
-constexpr char kHexChar[] = "0123456789abcdef";
-
-constexpr char kHexTable[513] =
- "000102030405060708090a0b0c0d0e0f"
- "101112131415161718191a1b1c1d1e1f"
- "202122232425262728292a2b2c2d2e2f"
- "303132333435363738393a3b3c3d3e3f"
- "404142434445464748494a4b4c4d4e4f"
- "505152535455565758595a5b5c5d5e5f"
- "606162636465666768696a6b6c6d6e6f"
- "707172737475767778797a7b7c7d7e7f"
- "808182838485868788898a8b8c8d8e8f"
- "909192939495969798999a9b9c9d9e9f"
- "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
- "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
- "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
- "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
- "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
- "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
-
// These are used for the leave_nulls_escaped argument to CUnescapeInternal().
constexpr bool kUnescapeNulls = false;
@@ -348,14 +327,14 @@ std::string CEscapeInternal(absl::string_view src, bool use_hex,
(last_hex_escape && absl::ascii_isxdigit(c)))) {
if (use_hex) {
dest.append("\\" "x");
- dest.push_back(kHexChar[c / 16]);
- dest.push_back(kHexChar[c % 16]);
+ dest.push_back(numbers_internal::kHexChar[c / 16]);
+ dest.push_back(numbers_internal::kHexChar[c % 16]);
is_hex_escape = true;
} else {
dest.append("\\");
- dest.push_back(kHexChar[c / 64]);
- dest.push_back(kHexChar[(c % 64) / 8]);
- dest.push_back(kHexChar[c % 8]);
+ dest.push_back(numbers_internal::kHexChar[c / 64]);
+ dest.push_back(numbers_internal::kHexChar[(c % 64) / 8]);
+ dest.push_back(numbers_internal::kHexChar[c % 8]);
}
} else {
dest.push_back(c);
@@ -1019,7 +998,7 @@ template <typename T>
void BytesToHexStringInternal(const unsigned char* src, T dest, ptrdiff_t num) {
auto dest_ptr = &dest[0];
for (auto src_ptr = src; src_ptr != (src + num); ++src_ptr, dest_ptr += 2) {
- const char* hex_p = &kHexTable[*src_ptr * 2];
+ const char* hex_p = &numbers_internal::kHexTable[*src_ptr * 2];
std::copy(hex_p, hex_p + 2, dest_ptr);
}
}
diff --git a/absl/strings/numbers.cc b/absl/strings/numbers.cc
index 38d14869..d7b94fc1 100644
--- a/absl/strings/numbers.cc
+++ b/absl/strings/numbers.cc
@@ -19,8 +19,8 @@
#include <algorithm>
#include <cassert>
-#include <cfloat> // for DBL_DIG and FLT_DIG
-#include <cmath> // for HUGE_VAL
+#include <cfloat> // for DBL_DIG and FLT_DIG
+#include <cmath> // for HUGE_VAL
#include <cstdint>
#include <cstdio>
#include <cstdlib>
@@ -34,6 +34,7 @@
#include "absl/base/internal/raw_logging.h"
#include "absl/strings/ascii.h"
#include "absl/strings/charconv.h"
+#include "absl/strings/escaping.h"
#include "absl/strings/internal/memutil.h"
#include "absl/strings/match.h"
#include "absl/strings/str_cat.h"
@@ -885,6 +886,28 @@ inline bool safe_uint_internal(absl::string_view text, IntType* value_p,
} // anonymous namespace
namespace numbers_internal {
+
+// Digit conversion.
+ABSL_CONST_INIT const char kHexChar[] = "0123456789abcdef";
+
+ABSL_CONST_INIT const char kHexTable[513] =
+ "000102030405060708090a0b0c0d0e0f"
+ "101112131415161718191a1b1c1d1e1f"
+ "202122232425262728292a2b2c2d2e2f"
+ "303132333435363738393a3b3c3d3e3f"
+ "404142434445464748494a4b4c4d4e4f"
+ "505152535455565758595a5b5c5d5e5f"
+ "606162636465666768696a6b6c6d6e6f"
+ "707172737475767778797a7b7c7d7e7f"
+ "808182838485868788898a8b8c8d8e8f"
+ "909192939495969798999a9b9c9d9e9f"
+ "a0a1a2a3a4a5a6a7a8a9aaabacadaeaf"
+ "b0b1b2b3b4b5b6b7b8b9babbbcbdbebf"
+ "c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"
+ "d0d1d2d3d4d5d6d7d8d9dadbdcdddedf"
+ "e0e1e2e3e4e5e6e7e8e9eaebecedeeef"
+ "f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff";
+
bool safe_strto32_base(absl::string_view text, int32_t* value, int base) {
return safe_int_internal<int32_t>(text, value, base);
}
@@ -900,6 +923,6 @@ bool safe_strtou32_base(absl::string_view text, uint32_t* value, int base) {
bool safe_strtou64_base(absl::string_view text, uint64_t* value, int base) {
return safe_uint_internal<uint64_t>(text, value, base);
}
-} // namespace numbers_internal
+} // namespace numbers_internal
} // namespace absl
diff --git a/absl/strings/numbers.h b/absl/strings/numbers.h
index 100839b0..745de67a 100644
--- a/absl/strings/numbers.h
+++ b/absl/strings/numbers.h
@@ -24,6 +24,10 @@
#ifndef ABSL_STRINGS_NUMBERS_H_
#define ABSL_STRINGS_NUMBERS_H_
+#ifdef __SSE4_2__
+#include <x86intrin.h>
+#endif
+
#include <cstddef>
#include <cstdlib>
#include <cstring>
@@ -32,6 +36,8 @@
#include <string>
#include <type_traits>
+#include "absl/base/internal/bits.h"
+#include "absl/base/internal/endian.h"
#include "absl/base/macros.h"
#include "absl/base/port.h"
#include "absl/numeric/int128.h"
@@ -54,7 +60,8 @@ ABSL_MUST_USE_RESULT bool SimpleAtoi(absl::string_view str, int_type* out);
// Converts the given string (optionally followed or preceded by ASCII
// whitespace) into a float, which may be rounded on overflow or underflow.
// See https://en.cppreference.com/w/c/string/byte/strtof for details about the
-// allowed formats for `str`. If any errors are encountered, this function
+// allowed formats for `str`, except SimpleAtof() is locale-indepdent and will
+// always use the "C" locale. If any errors are encountered, this function
// returns `false`, leaving `out` in an unspecified state.
ABSL_MUST_USE_RESULT bool SimpleAtof(absl::string_view str, float* out);
@@ -63,7 +70,8 @@ ABSL_MUST_USE_RESULT bool SimpleAtof(absl::string_view str, float* out);
// Converts the given string (optionally followed or preceded by ASCII
// whitespace) into a double, which may be rounded on overflow or underflow.
// See https://en.cppreference.com/w/c/string/byte/strtof for details about the
-// allowed formats for `str`. If any errors are encountered, this function
+// allowed formats for `str`, except SimpleAtod is locale-independent and will
+// always use the "C" locale. If any errors are encountered, this function
// returns `false`, leaving `out` in an unspecified state.
ABSL_MUST_USE_RESULT bool SimpleAtod(absl::string_view str, double* out);
@@ -84,6 +92,10 @@ ABSL_MUST_USE_RESULT bool SimpleAtob(absl::string_view str, bool* out);
namespace absl {
namespace numbers_internal {
+// Digit conversion.
+extern const char kHexChar[17]; // 0123456789abcdef
+extern const char kHexTable[513]; // 000102030405060708090a0b0c0d0e0f1011...
+
// safe_strto?() functions for implementing SimpleAtoi()
bool safe_strto32_base(absl::string_view text, int32_t* value, int base);
bool safe_strto64_base(absl::string_view text, int64_t* value, int base);
@@ -170,6 +182,35 @@ ABSL_MUST_USE_RESULT bool safe_strtoi_base(absl::string_view s, int_type* out,
return parsed;
}
+// FastHexToBufferZeroPad16()
+//
+// Outputs `val` into `out` as if by `snprintf(out, 17, "%016x", val)` but
+// without the terminating null character. Thus `out` must be of length >= 16.
+// Returns the number of non-pad digits of the output (it can never be zero
+// since 0 has one digit).
+inline size_t FastHexToBufferZeroPad16(uint64_t val, char* out) {
+ uint64_t be = absl::big_endian::FromHost64(val);
+#ifdef __SSE4_2__
+ const auto kNibbleMask = _mm_set1_epi8(0xf);
+ const auto kHexDigits = _mm_setr_epi8('0', '1', '2', '3', '4', '5', '6', '7',
+ '8', '9', 'a', 'b', 'c', 'd', 'e', 'f');
+ auto v = _mm_loadu_si64(reinterpret_cast<__m128i*>(&be)); // load lo dword
+ auto v4 = _mm_srli_epi64(v, 4); // shift 4 right
+ auto il = _mm_unpacklo_epi8(v4, v); // interleave bytes
+ auto m = _mm_and_si128(il, kNibbleMask); // mask out nibbles
+ auto hexchars = _mm_shuffle_epi8(kHexDigits, m); // hex chars
+ _mm_storeu_si128(reinterpret_cast<__m128i*>(out), hexchars);
+#else
+ for (int i = 0; i < 8; ++i) {
+ auto byte = (be >> (8 * i)) & 0xFF;
+ auto* hex = &absl::numbers_internal::kHexTable[byte * 2];
+ std::memcpy(out + 2 * i, hex, 2);
+ }
+#endif
+ // | 0x1 so that even 0 has 1 digit.
+ return 16 - absl::base_internal::CountLeadingZeros64(val | 0x1) / 4;
+}
+
} // namespace numbers_internal
// SimpleAtoi()
diff --git a/absl/strings/numbers_benchmark.cc b/absl/strings/numbers_benchmark.cc
index 54dbedd3..6e79b3e8 100644
--- a/absl/strings/numbers_benchmark.cc
+++ b/absl/strings/numbers_benchmark.cc
@@ -20,6 +20,8 @@
#include "benchmark/benchmark.h"
#include "absl/base/internal/raw_logging.h"
+#include "absl/random/distributions.h"
+#include "absl/random/random.h"
#include "absl/strings/numbers.h"
namespace {
@@ -260,4 +262,25 @@ BENCHMARK_TEMPLATE(BM_SimpleAtod, std::string)
->ArgPair(10, 4)
->ArgPair(10, 8);
+void BM_FastHexToBufferZeroPad16(benchmark::State& state) {
+ absl::BitGen rng;
+ std::vector<uint64_t> nums;
+ nums.resize(1000);
+ auto min = std::numeric_limits<uint64_t>::min();
+ auto max = std::numeric_limits<uint64_t>::max();
+ for (auto& num : nums) {
+ num = absl::LogUniform(rng, min, max);
+ }
+
+ char buf[16];
+ while (state.KeepRunningBatch(nums.size())) {
+ for (auto num : nums) {
+ auto digits = absl::numbers_internal::FastHexToBufferZeroPad16(num, buf);
+ benchmark::DoNotOptimize(digits);
+ benchmark::DoNotOptimize(buf);
+ }
+ }
+}
+BENCHMARK(BM_FastHexToBufferZeroPad16);
+
} // namespace
diff --git a/absl/strings/numbers_test.cc b/absl/strings/numbers_test.cc
index d964e562..b92b9a8c 100644
--- a/absl/strings/numbers_test.cc
+++ b/absl/strings/numbers_test.cc
@@ -17,6 +17,7 @@
#include "absl/strings/numbers.h"
#include <sys/types.h>
+
#include <cfenv> // NOLINT(build/c++11)
#include <cinttypes>
#include <climits>
@@ -36,10 +37,11 @@
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
-#include "absl/strings/str_cat.h"
-
+#include "absl/random/distributions.h"
+#include "absl/random/random.h"
#include "absl/strings/internal/numbers_test_common.h"
#include "absl/strings/internal/pow10_helper.h"
+#include "absl/strings/str_cat.h"
namespace {
@@ -1187,4 +1189,28 @@ TEST(StrToUint64Base, PrefixOnly) {
}
}
+void TestFastHexToBufferZeroPad16(uint64_t v) {
+ char buf[16];
+ auto digits = absl::numbers_internal::FastHexToBufferZeroPad16(v, buf);
+ absl::string_view res(buf, 16);
+ char buf2[17];
+ snprintf(buf2, sizeof(buf2), "%016" PRIx64, v);
+ EXPECT_EQ(res, buf2) << v;
+ size_t expected_digits = snprintf(buf2, sizeof(buf2), "%" PRIx64, v);
+ EXPECT_EQ(digits, expected_digits) << v;
+}
+
+TEST(FastHexToBufferZeroPad16, Smoke) {
+ TestFastHexToBufferZeroPad16(std::numeric_limits<uint64_t>::min());
+ TestFastHexToBufferZeroPad16(std::numeric_limits<uint64_t>::max());
+ TestFastHexToBufferZeroPad16(std::numeric_limits<int64_t>::min());
+ TestFastHexToBufferZeroPad16(std::numeric_limits<int64_t>::max());
+ absl::BitGen rng;
+ for (int i = 0; i < 100000; ++i) {
+ TestFastHexToBufferZeroPad16(
+ absl::LogUniform(rng, std::numeric_limits<uint64_t>::min(),
+ std::numeric_limits<uint64_t>::max()));
+ }
+}
+
} // namespace
diff --git a/absl/strings/str_cat.cc b/absl/strings/str_cat.cc
index 99619445..d5877899 100644
--- a/absl/strings/str_cat.cc
+++ b/absl/strings/str_cat.cc
@@ -15,12 +15,14 @@
#include "absl/strings/str_cat.h"
#include <assert.h>
+
#include <algorithm>
#include <cstdint>
#include <cstring>
#include "absl/strings/ascii.h"
#include "absl/strings/internal/resize_uninitialized.h"
+#include "absl/strings/numbers.h"
namespace absl {
@@ -28,9 +30,8 @@ AlphaNum::AlphaNum(Hex hex) {
char* const end = &digits_[numbers_internal::kFastToBufferSize];
char* writer = end;
uint64_t value = hex.value;
- static const char hexdigits[] = "0123456789abcdef";
do {
- *--writer = hexdigits[value & 0xF];
+ *--writer = absl::numbers_internal::kHexChar[value & 0xF];
value >>= 4;
} while (value != 0);
diff --git a/absl/strings/substitute.cc b/absl/strings/substitute.cc
index bc176950..36dbfe7d 100644
--- a/absl/strings/substitute.cc
+++ b/absl/strings/substitute.cc
@@ -94,7 +94,6 @@ void SubstituteAndAppendArray(std::string* output, absl::string_view format,
assert(target == output->data() + output->size());
}
-static const char kHexDigits[] = "0123456789abcdef";
Arg::Arg(const void* value) {
static_assert(sizeof(scratch_) >= sizeof(value) * 2 + 2,
"fix sizeof(scratch_)");
@@ -104,7 +103,7 @@ Arg::Arg(const void* value) {
char* ptr = scratch_ + sizeof(scratch_);
uintptr_t num = reinterpret_cast<uintptr_t>(value);
do {
- *--ptr = kHexDigits[num & 0xf];
+ *--ptr = absl::numbers_internal::kHexChar[num & 0xf];
num >>= 4;
} while (num != 0);
*--ptr = 'x';
@@ -119,7 +118,7 @@ Arg::Arg(Hex hex) {
char* writer = end;
uint64_t value = hex.value;
do {
- *--writer = kHexDigits[value & 0xF];
+ *--writer = absl::numbers_internal::kHexChar[value & 0xF];
value >>= 4;
} while (value != 0);