| // Copyright 2014 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_UTILS_VECTOR_H_ |
| #define V8_UTILS_VECTOR_H_ |
| |
| #include <algorithm> |
| #include <cstring> |
| #include <iterator> |
| |
| #include "src/common/checks.h" |
| #include "src/common/globals.h" |
| #include "src/utils/allocation.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| template <typename T> |
| class Vector { |
| public: |
| constexpr Vector() : start_(nullptr), length_(0) {} |
| |
| constexpr Vector(T* data, size_t length) : start_(data), length_(length) { |
| #ifdef V8_CAN_HAVE_DCHECK_IN_CONSTEXPR |
| DCHECK(length == 0 || data != nullptr); |
| #endif |
| } |
| |
| static Vector<T> New(size_t length) { |
| return Vector<T>(NewArray<T>(length), length); |
| } |
| |
| // Returns a vector using the same backing storage as this one, |
| // spanning from and including 'from', to but not including 'to'. |
| Vector<T> SubVector(size_t from, size_t to) const { |
| DCHECK_LE(from, to); |
| DCHECK_LE(to, length_); |
| return Vector<T>(begin() + from, to - from); |
| } |
| |
| // Returns the length of the vector. Only use this if you really need an |
| // integer return value. Use {size()} otherwise. |
| int length() const { |
| DCHECK_GE(std::numeric_limits<int>::max(), length_); |
| return static_cast<int>(length_); |
| } |
| |
| // Returns the length of the vector as a size_t. |
| constexpr size_t size() const { return length_; } |
| |
| // Returns whether or not the vector is empty. |
| constexpr bool empty() const { return length_ == 0; } |
| |
| // Access individual vector elements - checks bounds in debug mode. |
| T& operator[](size_t index) const { |
| DCHECK_LT(index, length_); |
| return start_[index]; |
| } |
| |
| const T& at(size_t index) const { return operator[](index); } |
| |
| T& first() { return start_[0]; } |
| |
| T& last() { |
| DCHECK_LT(0, length_); |
| return start_[length_ - 1]; |
| } |
| |
| // Returns a pointer to the start of the data in the vector. |
| constexpr T* begin() const { return start_; } |
| |
| // Returns a pointer past the end of the data in the vector. |
| constexpr T* end() const { return start_ + length_; } |
| |
| // Returns a clone of this vector with a new backing store. |
| Vector<T> Clone() const { |
| T* result = NewArray<T>(length_); |
| for (size_t i = 0; i < length_; i++) result[i] = start_[i]; |
| return Vector<T>(result, length_); |
| } |
| |
| void Truncate(size_t length) { |
| DCHECK(length <= length_); |
| length_ = length; |
| } |
| |
| // Releases the array underlying this vector. Once disposed the |
| // vector is empty. |
| void Dispose() { |
| DeleteArray(start_); |
| start_ = nullptr; |
| length_ = 0; |
| } |
| |
| Vector<T> operator+(size_t offset) { |
| DCHECK_LE(offset, length_); |
| return Vector<T>(start_ + offset, length_ - offset); |
| } |
| |
| Vector<T> operator+=(size_t offset) { |
| DCHECK_LE(offset, length_); |
| start_ += offset; |
| length_ -= offset; |
| return *this; |
| } |
| |
| // Implicit conversion from Vector<T> to Vector<const T>. |
| inline operator Vector<const T>() const { |
| return Vector<const T>::cast(*this); |
| } |
| |
| template <typename S> |
| static constexpr Vector<T> cast(Vector<S> input) { |
| return Vector<T>(reinterpret_cast<T*>(input.begin()), |
| input.length() * sizeof(S) / sizeof(T)); |
| } |
| |
| bool operator==(const Vector<const T> other) const { |
| if (length_ != other.length_) return false; |
| if (start_ == other.start_) return true; |
| for (size_t i = 0; i < length_; ++i) { |
| if (start_[i] != other.start_[i]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private: |
| T* start_; |
| size_t length_; |
| }; |
| |
| template <typename T> |
| class ScopedVector : public Vector<T> { |
| public: |
| explicit ScopedVector(size_t length) |
| : Vector<T>(NewArray<T>(length), length) {} |
| ~ScopedVector() { DeleteArray(this->begin()); } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedVector); |
| }; |
| |
| template <typename T> |
| class OwnedVector { |
| public: |
| MOVE_ONLY_WITH_DEFAULT_CONSTRUCTORS(OwnedVector); |
| OwnedVector(std::unique_ptr<T[]> data, size_t length) |
| : data_(std::move(data)), length_(length) { |
| DCHECK_IMPLIES(length_ > 0, data_ != nullptr); |
| } |
| // Implicit conversion from {OwnedVector<U>} to {OwnedVector<T>}, instantiable |
| // if {std::unique_ptr<U>} can be converted to {std::unique_ptr<T>}. |
| // Can be used to convert {OwnedVector<T>} to {OwnedVector<const T>}. |
| template <typename U, |
| typename = typename std::enable_if<std::is_convertible< |
| std::unique_ptr<U>, std::unique_ptr<T>>::value>::type> |
| OwnedVector(OwnedVector<U>&& other) |
| : data_(std::move(other.data_)), length_(other.length_) { |
| STATIC_ASSERT(sizeof(U) == sizeof(T)); |
| other.length_ = 0; |
| } |
| |
| // Returns the length of the vector as a size_t. |
| constexpr size_t size() const { return length_; } |
| |
| // Returns whether or not the vector is empty. |
| constexpr bool empty() const { return length_ == 0; } |
| |
| // Returns the pointer to the start of the data in the vector. |
| T* start() const { |
| DCHECK_IMPLIES(length_ > 0, data_ != nullptr); |
| return data_.get(); |
| } |
| |
| constexpr T* begin() const { return start(); } |
| constexpr T* end() const { return start() + size(); } |
| |
| // Access individual vector elements - checks bounds in debug mode. |
| T& operator[](size_t index) const { |
| DCHECK_LT(index, length_); |
| return data_[index]; |
| } |
| |
| // Returns a {Vector<T>} view of the data in this vector. |
| Vector<T> as_vector() const { return Vector<T>(start(), size()); } |
| |
| // Releases the backing data from this vector and transfers ownership to the |
| // caller. This vector will be empty afterwards. |
| std::unique_ptr<T[]> ReleaseData() { |
| length_ = 0; |
| return std::move(data_); |
| } |
| |
| // Allocates a new vector of the specified size via the default allocator. |
| static OwnedVector<T> New(size_t size) { |
| if (size == 0) return {}; |
| return OwnedVector<T>(std::unique_ptr<T[]>(new T[size]), size); |
| } |
| |
| // Allocates a new vector containing the specified collection of values. |
| // {Iterator} is the common type of {std::begin} and {std::end} called on a |
| // {const U&}. This function is only instantiable if that type exists. |
| template <typename U, typename Iterator = typename std::common_type< |
| decltype(std::begin(std::declval<const U&>())), |
| decltype(std::end(std::declval<const U&>()))>::type> |
| static OwnedVector<T> Of(const U& collection) { |
| Iterator begin = std::begin(collection); |
| Iterator end = std::end(collection); |
| OwnedVector<T> vec = New(std::distance(begin, end)); |
| std::copy(begin, end, vec.start()); |
| return vec; |
| } |
| |
| bool operator==(std::nullptr_t) const { return data_ == nullptr; } |
| bool operator!=(std::nullptr_t) const { return data_ != nullptr; } |
| |
| private: |
| template <typename U> |
| friend class OwnedVector; |
| |
| std::unique_ptr<T[]> data_; |
| size_t length_ = 0; |
| }; |
| |
| template <size_t N> |
| constexpr Vector<const uint8_t> StaticCharVector(const char (&array)[N]) { |
| return Vector<const uint8_t>::cast(Vector<const char>(array, N - 1)); |
| } |
| |
| // The resulting vector does not contain a null-termination byte. If you want |
| // the null byte, use ArrayVector("foo"). |
| inline Vector<const char> CStrVector(const char* data) { |
| return Vector<const char>(data, strlen(data)); |
| } |
| |
| inline Vector<const uint8_t> OneByteVector(const char* data, size_t length) { |
| return Vector<const uint8_t>(reinterpret_cast<const uint8_t*>(data), length); |
| } |
| |
| inline Vector<const uint8_t> OneByteVector(const char* data) { |
| return OneByteVector(data, strlen(data)); |
| } |
| |
| inline Vector<char> MutableCStrVector(char* data) { |
| return Vector<char>(data, strlen(data)); |
| } |
| |
| inline Vector<char> MutableCStrVector(char* data, size_t max) { |
| return Vector<char>(data, strnlen(data, max)); |
| } |
| |
| // For string literals, ArrayVector("foo") returns a vector ['f', 'o', 'o', \0] |
| // with length 4 and null-termination. |
| // If you want ['f', 'o', 'o'], use CStrVector("foo"). |
| template <typename T, size_t N> |
| inline constexpr Vector<T> ArrayVector(T (&arr)[N]) { |
| return Vector<T>{arr, N}; |
| } |
| |
| // Construct a Vector from a start pointer and a size. |
| template <typename T> |
| inline constexpr Vector<T> VectorOf(T* start, size_t size) { |
| return Vector<T>(start, size); |
| } |
| |
| // Construct a Vector from anything providing a {data()} and {size()} accessor. |
| template <typename Container> |
| inline constexpr auto VectorOf(Container&& c) |
| -> decltype(VectorOf(c.data(), c.size())) { |
| return VectorOf(c.data(), c.size()); |
| } |
| |
| template <typename T, size_t kSize> |
| class EmbeddedVector : public Vector<T> { |
| public: |
| EmbeddedVector() : Vector<T>(buffer_, kSize) {} |
| |
| explicit EmbeddedVector(const T& initial_value) : Vector<T>(buffer_, kSize) { |
| std::fill_n(buffer_, kSize, initial_value); |
| } |
| |
| private: |
| T buffer_[kSize]; |
| |
| DISALLOW_COPY_AND_ASSIGN(EmbeddedVector); |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_UTILS_VECTOR_H_ |