1551 lines
45 KiB
C++
1551 lines
45 KiB
C++
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// @author Mark Rabkin (mrabkin@fb.com)
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// @author Andrei Alexandrescu (andrei.alexandrescu@fb.com)
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#pragma once
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#include <folly/Portability.h>
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#include <folly/hash/SpookyHashV2.h>
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#include <folly/lang/Exception.h>
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#include <folly/portability/Constexpr.h>
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#include <folly/portability/String.h>
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#include <algorithm>
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#include <array>
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#include <cassert>
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#include <climits>
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#include <cstddef>
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#include <cstring>
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#include <iosfwd>
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#include <iterator>
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#include <stdexcept>
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#include <string>
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#include <type_traits>
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#if FOLLY_HAS_STRING_VIEW
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#include <string_view> // @manual
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#endif
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#include <folly/CpuId.h>
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#include <folly/Likely.h>
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#include <folly/Traits.h>
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#include <folly/detail/RangeCommon.h>
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#include <folly/detail/RangeSse42.h>
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// Ignore shadowing warnings within this file, so includers can use -Wshadow.
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FOLLY_PUSH_WARNING
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FOLLY_GNU_DISABLE_WARNING("-Wshadow")
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namespace folly {
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/**
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* Ubiquitous helper template for knowing what's a string.
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*/
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template <class T>
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struct IsSomeString : std::false_type {};
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template <typename Alloc>
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struct IsSomeString<std::basic_string<char, std::char_traits<char>, Alloc>>
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: std::true_type {};
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template <class Iter>
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class Range;
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/**
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* Finds the first occurrence of needle in haystack. The algorithm is on
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* average faster than O(haystack.size() * needle.size()) but not as fast
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* as Boyer-Moore. On the upside, it does not do any upfront
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* preprocessing and does not allocate memory.
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*/
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template <
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class Iter,
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class Comp = std::equal_to<typename Range<Iter>::value_type>>
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inline size_t
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qfind(const Range<Iter>& haystack, const Range<Iter>& needle, Comp eq = Comp());
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/**
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* Finds the first occurrence of needle in haystack. The result is the
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* offset reported to the beginning of haystack, or string::npos if
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* needle wasn't found.
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*/
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template <class Iter>
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size_t qfind(
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const Range<Iter>& haystack,
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const typename Range<Iter>::value_type& needle);
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/**
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* Finds the last occurrence of needle in haystack. The result is the
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* offset reported to the beginning of haystack, or string::npos if
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* needle wasn't found.
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*/
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template <class Iter>
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size_t rfind(
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const Range<Iter>& haystack,
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const typename Range<Iter>::value_type& needle);
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/**
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* Finds the first occurrence of any element of needle in
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* haystack. The algorithm is O(haystack.size() * needle.size()).
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*/
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template <class Iter>
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inline size_t qfind_first_of(
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const Range<Iter>& haystack,
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const Range<Iter>& needle);
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/**
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* Small internal helper - returns the value just before an iterator.
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*/
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namespace detail {
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/*
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* Use IsCharPointer<T>::type to enable const char* or char*.
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* Use IsCharPointer<T>::const_type to enable only const char*.
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*/
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template <class T>
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struct IsCharPointer {};
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template <>
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struct IsCharPointer<char*> {
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typedef int type;
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};
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template <>
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struct IsCharPointer<const char*> {
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typedef int const_type;
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typedef int type;
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};
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} // namespace detail
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/**
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* Range abstraction keeping a pair of iterators. We couldn't use
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* boost's similar range abstraction because we need an API identical
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* with the former StringPiece class, which is used by a lot of other
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* code. This abstraction does fulfill the needs of boost's
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* range-oriented algorithms though.
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*
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* (Keep memory lifetime in mind when using this class, since it
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* doesn't manage the data it refers to - just like an iterator
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* wouldn't.)
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*/
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template <class Iter>
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class Range {
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private:
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template <typename Alloc>
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using string = std::basic_string<char, std::char_traits<char>, Alloc>;
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public:
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typedef std::size_t size_type;
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typedef Iter iterator;
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typedef Iter const_iterator;
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typedef typename std::remove_reference<
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typename std::iterator_traits<Iter>::reference>::type value_type;
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using difference_type = typename std::iterator_traits<Iter>::difference_type;
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typedef typename std::iterator_traits<Iter>::reference reference;
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/**
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* For MutableStringPiece and MutableByteRange we define StringPiece
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* and ByteRange as const_range_type (for everything else its just
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* identity). We do that to enable operations such as find with
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* args which are const.
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*/
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typedef typename std::conditional<
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std::is_same<Iter, char*>::value ||
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std::is_same<Iter, unsigned char*>::value,
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Range<const value_type*>,
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Range<Iter>>::type const_range_type;
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typedef std::char_traits<typename std::remove_const<value_type>::type>
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traits_type;
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static const size_type npos;
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// Works for all iterators
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constexpr Range() : b_(), e_() {}
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constexpr Range(const Range&) = default;
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constexpr Range(Range&&) = default;
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public:
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// Works for all iterators
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constexpr Range(Iter start, Iter end) : b_(start), e_(end) {}
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// Works only for random-access iterators
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constexpr Range(Iter start, size_t size) : b_(start), e_(start + size) {}
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/* implicit */ Range(std::nullptr_t) = delete;
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constexpr /* implicit */ Range(Iter str)
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: b_(str), e_(str + constexpr_strlen(str)) {
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static_assert(
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std::is_same<int, typename detail::IsCharPointer<Iter>::type>::value,
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"This constructor is only available for character ranges");
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}
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template <
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class Alloc,
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class T = Iter,
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typename detail::IsCharPointer<T>::const_type = 0>
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/* implicit */ Range(const string<Alloc>& str)
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: b_(str.data()), e_(b_ + str.size()) {}
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template <
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class Alloc,
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class T = Iter,
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typename detail::IsCharPointer<T>::const_type = 0>
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Range(const string<Alloc>& str, typename string<Alloc>::size_type startFrom) {
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if (UNLIKELY(startFrom > str.size())) {
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throw_exception<std::out_of_range>("index out of range");
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}
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b_ = str.data() + startFrom;
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e_ = str.data() + str.size();
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}
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template <
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class Alloc,
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class T = Iter,
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typename detail::IsCharPointer<T>::const_type = 0>
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Range(
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const string<Alloc>& str,
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typename string<Alloc>::size_type startFrom,
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typename string<Alloc>::size_type size) {
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if (UNLIKELY(startFrom > str.size())) {
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throw_exception<std::out_of_range>("index out of range");
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}
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b_ = str.data() + startFrom;
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if (str.size() - startFrom < size) {
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e_ = str.data() + str.size();
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} else {
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e_ = b_ + size;
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}
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}
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Range(const Range& other, size_type first, size_type length = npos)
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: Range(other.subpiece(first, length)) {}
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template <
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class Container,
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class = typename std::enable_if<
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std::is_same<Iter, typename Container::const_pointer>::value>::type,
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class = decltype(
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Iter(std::declval<Container const&>().data()),
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Iter(
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std::declval<Container const&>().data() +
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std::declval<Container const&>().size()))>
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/* implicit */ constexpr Range(Container const& container)
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: b_(container.data()), e_(b_ + container.size()) {}
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template <
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class Container,
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class = typename std::enable_if<
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std::is_same<Iter, typename Container::const_pointer>::value>::type,
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class = decltype(
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Iter(std::declval<Container const&>().data()),
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Iter(
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std::declval<Container const&>().data() +
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std::declval<Container const&>().size()))>
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Range(Container const& container, typename Container::size_type startFrom) {
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auto const cdata = container.data();
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auto const csize = container.size();
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if (UNLIKELY(startFrom > csize)) {
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throw_exception<std::out_of_range>("index out of range");
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}
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b_ = cdata + startFrom;
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e_ = cdata + csize;
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}
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template <
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class Container,
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class = typename std::enable_if<
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std::is_same<Iter, typename Container::const_pointer>::value>::type,
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class = decltype(
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Iter(std::declval<Container const&>().data()),
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Iter(
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std::declval<Container const&>().data() +
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std::declval<Container const&>().size()))>
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Range(
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Container const& container,
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typename Container::size_type startFrom,
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typename Container::size_type size) {
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auto const cdata = container.data();
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auto const csize = container.size();
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if (UNLIKELY(startFrom > csize)) {
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throw_exception<std::out_of_range>("index out of range");
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}
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b_ = cdata + startFrom;
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if (csize - startFrom < size) {
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e_ = cdata + csize;
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} else {
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e_ = b_ + size;
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}
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}
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// Allow implicit conversion from Range<const char*> (aka StringPiece) to
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// Range<const unsigned char*> (aka ByteRange), as they're both frequently
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// used to represent ranges of bytes. Allow explicit conversion in the other
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// direction.
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template <
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class OtherIter,
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typename std::enable_if<
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(std::is_same<Iter, const unsigned char*>::value &&
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(std::is_same<OtherIter, const char*>::value ||
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std::is_same<OtherIter, char*>::value)),
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int>::type = 0>
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/* implicit */ Range(const Range<OtherIter>& other)
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: b_(reinterpret_cast<const unsigned char*>(other.begin())),
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e_(reinterpret_cast<const unsigned char*>(other.end())) {}
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template <
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class OtherIter,
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typename std::enable_if<
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(std::is_same<Iter, unsigned char*>::value &&
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std::is_same<OtherIter, char*>::value),
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int>::type = 0>
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/* implicit */ Range(const Range<OtherIter>& other)
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: b_(reinterpret_cast<unsigned char*>(other.begin())),
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e_(reinterpret_cast<unsigned char*>(other.end())) {}
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template <
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class OtherIter,
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typename std::enable_if<
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(std::is_same<Iter, const char*>::value &&
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(std::is_same<OtherIter, const unsigned char*>::value ||
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std::is_same<OtherIter, unsigned char*>::value)),
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int>::type = 0>
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explicit Range(const Range<OtherIter>& other)
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: b_(reinterpret_cast<const char*>(other.begin())),
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e_(reinterpret_cast<const char*>(other.end())) {}
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template <
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class OtherIter,
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typename std::enable_if<
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(std::is_same<Iter, char*>::value &&
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std::is_same<OtherIter, unsigned char*>::value),
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int>::type = 0>
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explicit Range(const Range<OtherIter>& other)
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: b_(reinterpret_cast<char*>(other.begin())),
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e_(reinterpret_cast<char*>(other.end())) {}
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// Allow implicit conversion from Range<From> to Range<To> if From is
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// implicitly convertible to To.
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template <
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class OtherIter,
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typename std::enable_if<
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(!std::is_same<Iter, OtherIter>::value &&
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std::is_convertible<OtherIter, Iter>::value),
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int>::type = 0>
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constexpr /* implicit */ Range(const Range<OtherIter>& other)
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: b_(other.begin()), e_(other.end()) {}
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// Allow explicit conversion from Range<From> to Range<To> if From is
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// explicitly convertible to To.
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template <
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class OtherIter,
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typename std::enable_if<
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(!std::is_same<Iter, OtherIter>::value &&
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!std::is_convertible<OtherIter, Iter>::value &&
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std::is_constructible<Iter, const OtherIter&>::value),
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int>::type = 0>
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constexpr explicit Range(const Range<OtherIter>& other)
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: b_(other.begin()), e_(other.end()) {}
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/**
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* Allow explicit construction of Range() from a std::array of a
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* convertible type.
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*
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* For instance, this allows constructing StringPiece from a
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* std::array<char, N> or a std::array<const char, N>
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*/
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template <
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class T,
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size_t N,
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typename = typename std::enable_if<
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std::is_convertible<const T*, Iter>::value>::type>
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constexpr explicit Range(const std::array<T, N>& array)
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: b_{array.empty() ? nullptr : &array.at(0)},
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e_{array.empty() ? nullptr : &array.at(0) + N} {}
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template <
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class T,
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size_t N,
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typename =
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typename std::enable_if<std::is_convertible<T*, Iter>::value>::type>
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constexpr explicit Range(std::array<T, N>& array)
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: b_{array.empty() ? nullptr : &array.at(0)},
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e_{array.empty() ? nullptr : &array.at(0) + N} {}
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Range& operator=(const Range& rhs) & = default;
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Range& operator=(Range&& rhs) & = default;
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template <
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class Alloc,
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class T = Iter,
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typename detail::IsCharPointer<T>::const_type = 0>
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Range& operator=(string<Alloc>&& rhs) = delete;
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void clear() {
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b_ = Iter();
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e_ = Iter();
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}
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void assign(Iter start, Iter end) {
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b_ = start;
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e_ = end;
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}
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void reset(Iter start, size_type size) {
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b_ = start;
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e_ = start + size;
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}
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// Works only for Range<const char*>
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template <typename Alloc>
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void reset(const string<Alloc>& str) {
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reset(str.data(), str.size());
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}
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constexpr size_type size() const {
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#if __clang__ || !__GNUC__ || __GNUC__ >= 7
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assert(b_ <= e_);
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#endif
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return size_type(e_ - b_);
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}
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constexpr size_type walk_size() const {
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return size_type(std::distance(b_, e_));
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}
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constexpr bool empty() const {
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return b_ == e_;
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}
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constexpr Iter data() const {
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return b_;
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}
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constexpr Iter start() const {
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return b_;
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}
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constexpr Iter begin() const {
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return b_;
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}
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constexpr Iter end() const {
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return e_;
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}
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constexpr Iter cbegin() const {
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return b_;
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}
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constexpr Iter cend() const {
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return e_;
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}
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value_type& front() {
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assert(b_ < e_);
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return *b_;
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}
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value_type& back() {
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assert(b_ < e_);
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return *std::prev(e_);
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}
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const value_type& front() const {
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assert(b_ < e_);
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return *b_;
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}
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const value_type& back() const {
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assert(b_ < e_);
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return *std::prev(e_);
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}
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private:
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// It would be nice to be able to implicit convert to any target type
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// T for which either an (Iter, Iter) or (Iter, size_type) noexcept
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// constructor was available, and explicitly convert to any target
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// type for which those signatures were available but not noexcept.
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// The problem is that this creates ambiguity when there is also a
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// T constructor that takes a type U that is implicitly convertible
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// from Range.
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//
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// To avoid ambiguity, we need to avoid having explicit operator T
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// and implicit operator U coexist when T is constructible from U.
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// U cannot be deduced when searching for operator T (and C++ won't
|
|
// perform an existential search for it), so we must limit the implicit
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// target types to a finite set that we can enumerate.
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|
//
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|
// At the moment the set of implicit target types consists of just
|
|
// std::string_view (when it is available).
|
|
#if FOLLY_HAS_STRING_VIEW
|
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struct NotStringView {};
|
|
template <typename ValueType>
|
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struct StringViewType
|
|
: std::conditional<
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std::is_pod<std::remove_const_t<ValueType>>::value,
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|
std::basic_string_view<std::remove_const_t<ValueType>>,
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NotStringView> {};
|
|
|
|
template <typename Target>
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struct IsConstructibleViaStringView
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|
: Conjunction<
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|
std::is_constructible<
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_t<StringViewType<value_type>>,
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Iter const&,
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size_type>,
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std::is_constructible<Target, _t<StringViewType<value_type>>>> {};
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#else
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template <typename Target>
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using IsConstructibleViaStringView = std::false_type;
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#endif
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|
|
public:
|
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/// explicit operator conversion to any compatible type
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|
///
|
|
/// A compatible type is one which is constructible with an iterator and a
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|
/// size (preferred), or a pair of iterators (fallback), passed by const-ref.
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///
|
|
/// Participates in overload resolution precisely when the target type is
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|
/// compatible. This allows std::is_constructible compile-time checks to work.
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|
template <
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typename Tgt,
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|
std::enable_if_t<
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|
std::is_constructible<Tgt, Iter const&, size_type>::value &&
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|
!IsConstructibleViaStringView<Tgt>::value,
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|
int> = 0>
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|
constexpr explicit operator Tgt() const noexcept(
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|
std::is_nothrow_constructible<Tgt, Iter const&, size_type>::value) {
|
|
return Tgt(b_, walk_size());
|
|
}
|
|
template <
|
|
typename Tgt,
|
|
std::enable_if_t<
|
|
!std::is_constructible<Tgt, Iter const&, size_type>::value &&
|
|
std::is_constructible<Tgt, Iter const&, Iter const&>::value &&
|
|
!IsConstructibleViaStringView<Tgt>::value,
|
|
int> = 0>
|
|
constexpr explicit operator Tgt() const noexcept(
|
|
std::is_nothrow_constructible<Tgt, Iter const&, Iter const&>::value) {
|
|
return Tgt(b_, e_);
|
|
}
|
|
|
|
#if FOLLY_HAS_STRING_VIEW
|
|
/// implicit operator conversion to std::string_view
|
|
template <
|
|
typename Tgt,
|
|
typename ValueType = value_type,
|
|
std::enable_if_t<
|
|
StrictConjunction<
|
|
std::is_same<Tgt, _t<StringViewType<ValueType>>>,
|
|
std::is_constructible<
|
|
_t<StringViewType<ValueType>>,
|
|
Iter const&,
|
|
size_type>>::value,
|
|
int> = 0>
|
|
constexpr operator Tgt() const noexcept(
|
|
std::is_nothrow_constructible<Tgt, Iter const&, size_type>::value) {
|
|
return Tgt(b_, walk_size());
|
|
}
|
|
#endif
|
|
|
|
/// explicit non-operator conversion to any compatible type
|
|
///
|
|
/// A compatible type is one which is constructible with an iterator and a
|
|
/// size (preferred), or a pair of iterators (fallback), passed by const-ref.
|
|
///
|
|
/// Participates in overload resolution precisely when the target type is
|
|
/// compatible. This allows is_invocable compile-time checks to work.
|
|
///
|
|
/// Provided in addition to the explicit operator conversion to permit passing
|
|
/// additional arguments to the target type constructor. A canonical example
|
|
/// of an additional argument might be an allocator, where the target type is
|
|
/// some specialization of std::vector or std::basic_string in a context which
|
|
/// requires a non-default-constructed allocator.
|
|
template <typename Tgt, typename... Args>
|
|
constexpr std::enable_if_t<
|
|
std::is_constructible<Tgt, Iter const&, size_type>::value,
|
|
Tgt>
|
|
to(Args&&... args) const noexcept(
|
|
std::is_nothrow_constructible<Tgt, Iter const&, size_type, Args&&...>::
|
|
value) {
|
|
return Tgt(b_, walk_size(), static_cast<Args&&>(args)...);
|
|
}
|
|
template <typename Tgt, typename... Args>
|
|
constexpr std::enable_if_t<
|
|
!std::is_constructible<Tgt, Iter const&, size_type>::value &&
|
|
std::is_constructible<Tgt, Iter const&, Iter const&>::value,
|
|
Tgt>
|
|
to(Args&&... args) const noexcept(
|
|
std::is_nothrow_constructible<Tgt, Iter const&, Iter const&, Args&&...>::
|
|
value) {
|
|
return Tgt(b_, e_, static_cast<Args&&>(args)...);
|
|
}
|
|
|
|
// Works only for Range<const char*> and Range<char*>
|
|
std::string str() const {
|
|
return to<std::string>();
|
|
}
|
|
std::string toString() const {
|
|
return to<std::string>();
|
|
}
|
|
|
|
const_range_type castToConst() const {
|
|
return const_range_type(*this);
|
|
}
|
|
|
|
int compare(const const_range_type& o) const {
|
|
const size_type tsize = this->size();
|
|
const size_type osize = o.size();
|
|
const size_type msize = std::min(tsize, osize);
|
|
int r = traits_type::compare(data(), o.data(), msize);
|
|
if (r == 0 && tsize != osize) {
|
|
// We check the signed bit of the subtraction and bit shift it
|
|
// to produce either 0 or 2. The subtraction yields the
|
|
// comparison values of either -1 or 1.
|
|
r = (static_cast<int>((osize - tsize) >> (CHAR_BIT * sizeof(size_t) - 1))
|
|
<< 1) -
|
|
1;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
value_type& operator[](size_t i) {
|
|
assert(i < size());
|
|
return b_[i];
|
|
}
|
|
|
|
const value_type& operator[](size_t i) const {
|
|
assert(i < size());
|
|
return b_[i];
|
|
}
|
|
|
|
value_type& at(size_t i) {
|
|
if (i >= size()) {
|
|
throw_exception<std::out_of_range>("index out of range");
|
|
}
|
|
return b_[i];
|
|
}
|
|
|
|
const value_type& at(size_t i) const {
|
|
if (i >= size()) {
|
|
throw_exception<std::out_of_range>("index out of range");
|
|
}
|
|
return b_[i];
|
|
}
|
|
|
|
// Do NOT use this function, which was left behind for backwards
|
|
// compatibility. Use SpookyHashV2 instead -- it is faster, and produces
|
|
// a 64-bit hash, which means dramatically fewer collisions in large maps.
|
|
// (The above advice does not apply if you are targeting a 32-bit system.)
|
|
//
|
|
// Works only for Range<const char*> and Range<char*>
|
|
//
|
|
//
|
|
// ** WANT TO GET RID OF THIS LINT? **
|
|
//
|
|
// A) Use a better hash function (*cough*folly::Hash*cough*), but
|
|
// only if you don't serialize data in a format that depends on
|
|
// this formula (ie the writer and reader assume this exact hash
|
|
// function is used).
|
|
//
|
|
// B) If you have to use this exact function then make your own hasher
|
|
// object and copy the body over (see thrift example: D3972362).
|
|
// https://github.com/facebook/fbthrift/commit/f8ed502e24ab4a32a9d5f266580
|
|
[[deprecated(
|
|
"Replace with folly::Hash if the hash is not serialized")]] uint32_t
|
|
hash() const {
|
|
// Taken from fbi/nstring.h:
|
|
// Quick and dirty bernstein hash...fine for short ascii strings
|
|
uint32_t hash = 5381;
|
|
for (size_t ix = 0; ix < size(); ix++) {
|
|
hash = ((hash << 5) + hash) + b_[ix];
|
|
}
|
|
return hash;
|
|
}
|
|
|
|
void advance(size_type n) {
|
|
if (UNLIKELY(n > size())) {
|
|
throw_exception<std::out_of_range>("index out of range");
|
|
}
|
|
b_ += n;
|
|
}
|
|
|
|
void subtract(size_type n) {
|
|
if (UNLIKELY(n > size())) {
|
|
throw_exception<std::out_of_range>("index out of range");
|
|
}
|
|
e_ -= n;
|
|
}
|
|
|
|
Range subpiece(size_type first, size_type length = npos) const {
|
|
if (UNLIKELY(first > size())) {
|
|
throw_exception<std::out_of_range>("index out of range");
|
|
}
|
|
|
|
return Range(b_ + first, std::min(length, size() - first));
|
|
}
|
|
|
|
// unchecked versions
|
|
void uncheckedAdvance(size_type n) {
|
|
assert(n <= size());
|
|
b_ += n;
|
|
}
|
|
|
|
void uncheckedSubtract(size_type n) {
|
|
assert(n <= size());
|
|
e_ -= n;
|
|
}
|
|
|
|
Range uncheckedSubpiece(size_type first, size_type length = npos) const {
|
|
assert(first <= size());
|
|
return Range(b_ + first, std::min(length, size() - first));
|
|
}
|
|
|
|
void pop_front() {
|
|
assert(b_ < e_);
|
|
++b_;
|
|
}
|
|
|
|
void pop_back() {
|
|
assert(b_ < e_);
|
|
--e_;
|
|
}
|
|
|
|
// string work-alike functions
|
|
size_type find(const_range_type str) const {
|
|
return qfind(castToConst(), str);
|
|
}
|
|
|
|
size_type find(const_range_type str, size_t pos) const {
|
|
if (pos > size()) {
|
|
return std::string::npos;
|
|
}
|
|
size_t ret = qfind(castToConst().subpiece(pos), str);
|
|
return ret == npos ? ret : ret + pos;
|
|
}
|
|
|
|
size_type find(Iter s, size_t pos, size_t n) const {
|
|
if (pos > size()) {
|
|
return std::string::npos;
|
|
}
|
|
auto forFinding = castToConst();
|
|
size_t ret = qfind(
|
|
pos ? forFinding.subpiece(pos) : forFinding, const_range_type(s, n));
|
|
return ret == npos ? ret : ret + pos;
|
|
}
|
|
|
|
// Works only for Range<(const) (unsigned) char*> which have Range(Iter) ctor
|
|
size_type find(const Iter s) const {
|
|
return qfind(castToConst(), const_range_type(s));
|
|
}
|
|
|
|
// Works only for Range<(const) (unsigned) char*> which have Range(Iter) ctor
|
|
size_type find(const Iter s, size_t pos) const {
|
|
if (pos > size()) {
|
|
return std::string::npos;
|
|
}
|
|
size_type ret = qfind(castToConst().subpiece(pos), const_range_type(s));
|
|
return ret == npos ? ret : ret + pos;
|
|
}
|
|
|
|
size_type find(value_type c) const {
|
|
return qfind(castToConst(), c);
|
|
}
|
|
|
|
size_type rfind(value_type c) const {
|
|
return folly::rfind(castToConst(), c);
|
|
}
|
|
|
|
size_type find(value_type c, size_t pos) const {
|
|
if (pos > size()) {
|
|
return std::string::npos;
|
|
}
|
|
size_type ret = qfind(castToConst().subpiece(pos), c);
|
|
return ret == npos ? ret : ret + pos;
|
|
}
|
|
|
|
size_type find_first_of(const_range_type needles) const {
|
|
return qfind_first_of(castToConst(), needles);
|
|
}
|
|
|
|
size_type find_first_of(const_range_type needles, size_t pos) const {
|
|
if (pos > size()) {
|
|
return std::string::npos;
|
|
}
|
|
size_type ret = qfind_first_of(castToConst().subpiece(pos), needles);
|
|
return ret == npos ? ret : ret + pos;
|
|
}
|
|
|
|
// Works only for Range<(const) (unsigned) char*> which have Range(Iter) ctor
|
|
size_type find_first_of(Iter needles) const {
|
|
return find_first_of(const_range_type(needles));
|
|
}
|
|
|
|
// Works only for Range<(const) (unsigned) char*> which have Range(Iter) ctor
|
|
size_type find_first_of(Iter needles, size_t pos) const {
|
|
return find_first_of(const_range_type(needles), pos);
|
|
}
|
|
|
|
size_type find_first_of(Iter needles, size_t pos, size_t n) const {
|
|
return find_first_of(const_range_type(needles, n), pos);
|
|
}
|
|
|
|
size_type find_first_of(value_type c) const {
|
|
return find(c);
|
|
}
|
|
|
|
size_type find_first_of(value_type c, size_t pos) const {
|
|
return find(c, pos);
|
|
}
|
|
|
|
/**
|
|
* Determine whether the range contains the given subrange or item.
|
|
*
|
|
* Note: Call find() directly if the index is needed.
|
|
*/
|
|
bool contains(const const_range_type& other) const {
|
|
return find(other) != std::string::npos;
|
|
}
|
|
|
|
bool contains(const value_type& other) const {
|
|
return find(other) != std::string::npos;
|
|
}
|
|
|
|
void swap(Range& rhs) {
|
|
std::swap(b_, rhs.b_);
|
|
std::swap(e_, rhs.e_);
|
|
}
|
|
|
|
/**
|
|
* Does this Range start with another range?
|
|
*/
|
|
bool startsWith(const const_range_type& other) const {
|
|
return size() >= other.size() &&
|
|
castToConst().subpiece(0, other.size()) == other;
|
|
}
|
|
bool startsWith(value_type c) const {
|
|
return !empty() && front() == c;
|
|
}
|
|
|
|
template <class Comp>
|
|
bool startsWith(const const_range_type& other, Comp&& eq) const {
|
|
if (size() < other.size()) {
|
|
return false;
|
|
}
|
|
auto const trunc = subpiece(0, other.size());
|
|
return std::equal(
|
|
trunc.begin(), trunc.end(), other.begin(), std::forward<Comp>(eq));
|
|
}
|
|
|
|
/**
|
|
* Does this Range end with another range?
|
|
*/
|
|
bool endsWith(const const_range_type& other) const {
|
|
return size() >= other.size() &&
|
|
castToConst().subpiece(size() - other.size()) == other;
|
|
}
|
|
bool endsWith(value_type c) const {
|
|
return !empty() && back() == c;
|
|
}
|
|
|
|
template <class Comp>
|
|
bool endsWith(const const_range_type& other, Comp&& eq) const {
|
|
if (size() < other.size()) {
|
|
return false;
|
|
}
|
|
auto const trunc = subpiece(size() - other.size());
|
|
return std::equal(
|
|
trunc.begin(), trunc.end(), other.begin(), std::forward<Comp>(eq));
|
|
}
|
|
|
|
template <class Comp>
|
|
bool equals(const const_range_type& other, Comp&& eq) const {
|
|
return size() == other.size() &&
|
|
std::equal(begin(), end(), other.begin(), std::forward<Comp>(eq));
|
|
}
|
|
|
|
/**
|
|
* Remove the items in [b, e), as long as this subrange is at the beginning
|
|
* or end of the Range.
|
|
*
|
|
* Required for boost::algorithm::trim()
|
|
*/
|
|
void erase(Iter b, Iter e) {
|
|
if (b == b_) {
|
|
b_ = e;
|
|
} else if (e == e_) {
|
|
e_ = b;
|
|
} else {
|
|
throw_exception<std::out_of_range>("index out of range");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Remove the given prefix and return true if the range starts with the given
|
|
* prefix; return false otherwise.
|
|
*/
|
|
bool removePrefix(const const_range_type& prefix) {
|
|
return startsWith(prefix) && (b_ += prefix.size(), true);
|
|
}
|
|
bool removePrefix(value_type prefix) {
|
|
return startsWith(prefix) && (++b_, true);
|
|
}
|
|
|
|
/**
|
|
* Remove the given suffix and return true if the range ends with the given
|
|
* suffix; return false otherwise.
|
|
*/
|
|
bool removeSuffix(const const_range_type& suffix) {
|
|
return endsWith(suffix) && (e_ -= suffix.size(), true);
|
|
}
|
|
bool removeSuffix(value_type suffix) {
|
|
return endsWith(suffix) && (--e_, true);
|
|
}
|
|
|
|
/**
|
|
* Replaces the content of the range, starting at position 'pos', with
|
|
* contents of 'replacement'. Entire 'replacement' must fit into the
|
|
* range. Returns false if 'replacements' does not fit. Example use:
|
|
*
|
|
* char in[] = "buffer";
|
|
* auto msp = MutablesStringPiece(input);
|
|
* EXPECT_TRUE(msp.replaceAt(2, "tt"));
|
|
* EXPECT_EQ(msp, "butter");
|
|
*
|
|
* // not enough space
|
|
* EXPECT_FALSE(msp.replace(msp.size() - 1, "rr"));
|
|
* EXPECT_EQ(msp, "butter"); // unchanged
|
|
*/
|
|
bool replaceAt(size_t pos, const_range_type replacement) {
|
|
if (size() < pos + replacement.size()) {
|
|
return false;
|
|
}
|
|
|
|
std::copy(replacement.begin(), replacement.end(), begin() + pos);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Replaces all occurences of 'source' with 'dest'. Returns number
|
|
* of replacements made. Source and dest have to have the same
|
|
* length. Throws if the lengths are different. If 'source' is a
|
|
* pattern that is overlapping with itself, we perform sequential
|
|
* replacement: "aaaaaaa".replaceAll("aa", "ba") --> "bababaa"
|
|
*
|
|
* Example use:
|
|
*
|
|
* char in[] = "buffer";
|
|
* auto msp = MutablesStringPiece(input);
|
|
* EXPECT_EQ(msp.replaceAll("ff","tt"), 1);
|
|
* EXPECT_EQ(msp, "butter");
|
|
*/
|
|
size_t replaceAll(const_range_type source, const_range_type dest) {
|
|
if (source.size() != dest.size()) {
|
|
throw_exception<std::invalid_argument>(
|
|
"replacement must have the same size as source");
|
|
}
|
|
|
|
if (dest.empty()) {
|
|
return 0;
|
|
}
|
|
|
|
size_t pos = 0;
|
|
size_t num_replaced = 0;
|
|
size_type found = std::string::npos;
|
|
while ((found = find(source, pos)) != std::string::npos) {
|
|
replaceAt(found, dest);
|
|
pos += source.size();
|
|
++num_replaced;
|
|
}
|
|
|
|
return num_replaced;
|
|
}
|
|
|
|
/**
|
|
* Splits this `Range` `[b, e)` in the position `i` dictated by the next
|
|
* occurence of `delimiter`.
|
|
*
|
|
* Returns a new `Range` `[b, i)` and adjusts this range to start right after
|
|
* the delimiter's position. This range will be empty if the delimiter is not
|
|
* found. If called on an empty `Range`, both this and the returned `Range`
|
|
* will be empty.
|
|
*
|
|
* Example:
|
|
*
|
|
* folly::StringPiece s("sample string for split_next");
|
|
* auto p = s.split_step(' ');
|
|
*
|
|
* // prints "string for split_next"
|
|
* cout << s << endl;
|
|
*
|
|
* // prints "sample"
|
|
* cout << p << endl;
|
|
*
|
|
* Example 2:
|
|
*
|
|
* void tokenize(StringPiece s, char delimiter) {
|
|
* while (!s.empty()) {
|
|
* cout << s.split_step(delimiter);
|
|
* }
|
|
* }
|
|
*
|
|
* @author: Marcelo Juchem <marcelo@fb.com>
|
|
*/
|
|
Range split_step(value_type delimiter) {
|
|
auto i = std::find(b_, e_, delimiter);
|
|
Range result(b_, i);
|
|
|
|
b_ = i == e_ ? e_ : std::next(i);
|
|
|
|
return result;
|
|
}
|
|
|
|
Range split_step(Range delimiter) {
|
|
auto i = find(delimiter);
|
|
Range result(b_, i == std::string::npos ? size() : i);
|
|
|
|
b_ = result.end() == e_
|
|
? e_
|
|
: std::next(
|
|
result.end(),
|
|
typename std::iterator_traits<Iter>::difference_type(
|
|
delimiter.size()));
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* Convenience method that calls `split_step()` and passes the result to a
|
|
* functor, returning whatever the functor does. Any additional arguments
|
|
* `args` passed to this function are perfectly forwarded to the functor.
|
|
*
|
|
* Say you have a functor with this signature:
|
|
*
|
|
* Foo fn(Range r) { }
|
|
*
|
|
* `split_step()`'s return type will be `Foo`. It works just like:
|
|
*
|
|
* auto result = fn(myRange.split_step(' '));
|
|
*
|
|
* A functor returning `void` is also supported.
|
|
*
|
|
* Example:
|
|
*
|
|
* void do_some_parsing(folly::StringPiece s) {
|
|
* auto version = s.split_step(' ', [&](folly::StringPiece x) {
|
|
* if (x.empty()) {
|
|
* throw std::invalid_argument("empty string");
|
|
* }
|
|
* return std::strtoull(x.begin(), x.end(), 16);
|
|
* });
|
|
*
|
|
* // ...
|
|
* }
|
|
*
|
|
* struct Foo {
|
|
* void parse(folly::StringPiece s) {
|
|
* s.split_step(' ', parse_field, bar, 10);
|
|
* s.split_step('\t', parse_field, baz, 20);
|
|
*
|
|
* auto const kludge = [](folly::StringPiece x, int &out, int def) {
|
|
* if (x == "null") {
|
|
* out = 0;
|
|
* } else {
|
|
* parse_field(x, out, def);
|
|
* }
|
|
* };
|
|
*
|
|
* s.split_step('\t', kludge, gaz);
|
|
* s.split_step(' ', kludge, foo);
|
|
* }
|
|
*
|
|
* private:
|
|
* int bar;
|
|
* int baz;
|
|
* int gaz;
|
|
* int foo;
|
|
*
|
|
* static parse_field(folly::StringPiece s, int &out, int def) {
|
|
* try {
|
|
* out = folly::to<int>(s);
|
|
* } catch (std::exception const &) {
|
|
* value = def;
|
|
* }
|
|
* }
|
|
* };
|
|
*
|
|
* @author: Marcelo Juchem <marcelo@fb.com>
|
|
*/
|
|
template <typename TProcess, typename... Args>
|
|
auto split_step(value_type delimiter, TProcess&& process, Args&&... args)
|
|
-> decltype(process(std::declval<Range>(), std::forward<Args>(args)...)) {
|
|
return process(split_step(delimiter), std::forward<Args>(args)...);
|
|
}
|
|
|
|
template <typename TProcess, typename... Args>
|
|
auto split_step(Range delimiter, TProcess&& process, Args&&... args)
|
|
-> decltype(process(std::declval<Range>(), std::forward<Args>(args)...)) {
|
|
return process(split_step(delimiter), std::forward<Args>(args)...);
|
|
}
|
|
|
|
private:
|
|
Iter b_, e_;
|
|
};
|
|
|
|
template <class Iter>
|
|
const typename Range<Iter>::size_type Range<Iter>::npos = std::string::npos;
|
|
|
|
template <class Iter>
|
|
void swap(Range<Iter>& lhs, Range<Iter>& rhs) {
|
|
lhs.swap(rhs);
|
|
}
|
|
|
|
/**
|
|
* Create a range from two iterators, with type deduction.
|
|
*/
|
|
template <class Iter>
|
|
constexpr Range<Iter> range(Iter first, Iter last) {
|
|
return Range<Iter>(first, last);
|
|
}
|
|
|
|
/*
|
|
* Creates a range to reference the contents of a contiguous-storage container.
|
|
*/
|
|
// Use pointers for types with '.data()' member
|
|
template <class Collection>
|
|
constexpr auto range(Collection& v) -> Range<decltype(v.data())> {
|
|
return Range<decltype(v.data())>(v.data(), v.data() + v.size());
|
|
}
|
|
template <class Collection>
|
|
constexpr auto range(Collection const& v) -> Range<decltype(v.data())> {
|
|
return Range<decltype(v.data())>(v.data(), v.data() + v.size());
|
|
}
|
|
template <class Collection>
|
|
constexpr auto crange(Collection const& v) -> Range<decltype(v.data())> {
|
|
return Range<decltype(v.data())>(v.data(), v.data() + v.size());
|
|
}
|
|
|
|
template <class T, size_t n>
|
|
constexpr Range<T*> range(T (&array)[n]) {
|
|
return Range<T*>(array, array + n);
|
|
}
|
|
template <class T, size_t n>
|
|
constexpr Range<T const*> range(T const (&array)[n]) {
|
|
return Range<T const*>(array, array + n);
|
|
}
|
|
template <class T, size_t n>
|
|
constexpr Range<T const*> crange(T const (&array)[n]) {
|
|
return Range<T const*>(array, array + n);
|
|
}
|
|
|
|
template <class T, size_t n>
|
|
constexpr Range<T*> range(std::array<T, n>& array) {
|
|
return Range<T*>{array};
|
|
}
|
|
template <class T, size_t n>
|
|
constexpr Range<T const*> range(std::array<T, n> const& array) {
|
|
return Range<T const*>{array};
|
|
}
|
|
template <class T, size_t n>
|
|
constexpr Range<T const*> crange(std::array<T, n> const& array) {
|
|
return Range<T const*>{array};
|
|
}
|
|
|
|
typedef Range<const char*> StringPiece;
|
|
typedef Range<char*> MutableStringPiece;
|
|
typedef Range<const unsigned char*> ByteRange;
|
|
typedef Range<unsigned char*> MutableByteRange;
|
|
|
|
template <class C>
|
|
std::basic_ostream<C>& operator<<(
|
|
std::basic_ostream<C>& os,
|
|
Range<C const*> piece) {
|
|
using StreamSize = decltype(os.width());
|
|
os.write(piece.start(), static_cast<StreamSize>(piece.size()));
|
|
return os;
|
|
}
|
|
|
|
template <class C>
|
|
std::basic_ostream<C>& operator<<(std::basic_ostream<C>& os, Range<C*> piece) {
|
|
using StreamSize = decltype(os.width());
|
|
os.write(piece.start(), static_cast<StreamSize>(piece.size()));
|
|
return os;
|
|
}
|
|
|
|
/**
|
|
* Templated comparison operators
|
|
*/
|
|
|
|
template <class Iter>
|
|
inline bool operator==(const Range<Iter>& lhs, const Range<Iter>& rhs) {
|
|
return lhs.size() == rhs.size() && lhs.compare(rhs) == 0;
|
|
}
|
|
|
|
template <class Iter>
|
|
inline bool operator!=(const Range<Iter>& lhs, const Range<Iter>& rhs) {
|
|
return !(operator==(lhs, rhs));
|
|
}
|
|
|
|
template <class Iter>
|
|
inline bool operator<(const Range<Iter>& lhs, const Range<Iter>& rhs) {
|
|
return lhs.compare(rhs) < 0;
|
|
}
|
|
|
|
template <class Iter>
|
|
inline bool operator<=(const Range<Iter>& lhs, const Range<Iter>& rhs) {
|
|
return lhs.compare(rhs) <= 0;
|
|
}
|
|
|
|
template <class Iter>
|
|
inline bool operator>(const Range<Iter>& lhs, const Range<Iter>& rhs) {
|
|
return lhs.compare(rhs) > 0;
|
|
}
|
|
|
|
template <class Iter>
|
|
inline bool operator>=(const Range<Iter>& lhs, const Range<Iter>& rhs) {
|
|
return lhs.compare(rhs) >= 0;
|
|
}
|
|
|
|
/**
|
|
* Specializations of comparison operators for StringPiece
|
|
*/
|
|
|
|
namespace detail {
|
|
|
|
template <class A, class B>
|
|
struct ComparableAsStringPiece {
|
|
enum {
|
|
value = (std::is_convertible<A, StringPiece>::value &&
|
|
std::is_same<B, StringPiece>::value) ||
|
|
(std::is_convertible<B, StringPiece>::value &&
|
|
std::is_same<A, StringPiece>::value)
|
|
};
|
|
};
|
|
|
|
} // namespace detail
|
|
|
|
/**
|
|
* operator== through conversion for Range<const char*>
|
|
*/
|
|
template <class T, class U>
|
|
std::enable_if_t<detail::ComparableAsStringPiece<T, U>::value, bool> operator==(
|
|
const T& lhs,
|
|
const U& rhs) {
|
|
return StringPiece(lhs) == StringPiece(rhs);
|
|
}
|
|
|
|
/**
|
|
* operator!= through conversion for Range<const char*>
|
|
*/
|
|
template <class T, class U>
|
|
std::enable_if_t<detail::ComparableAsStringPiece<T, U>::value, bool> operator!=(
|
|
const T& lhs,
|
|
const U& rhs) {
|
|
return StringPiece(lhs) != StringPiece(rhs);
|
|
}
|
|
|
|
/**
|
|
* operator< through conversion for Range<const char*>
|
|
*/
|
|
template <class T, class U>
|
|
std::enable_if_t<detail::ComparableAsStringPiece<T, U>::value, bool> operator<(
|
|
const T& lhs,
|
|
const U& rhs) {
|
|
return StringPiece(lhs) < StringPiece(rhs);
|
|
}
|
|
|
|
/**
|
|
* operator> through conversion for Range<const char*>
|
|
*/
|
|
template <class T, class U>
|
|
std::enable_if_t<detail::ComparableAsStringPiece<T, U>::value, bool> operator>(
|
|
const T& lhs,
|
|
const U& rhs) {
|
|
return StringPiece(lhs) > StringPiece(rhs);
|
|
}
|
|
|
|
/**
|
|
* operator< through conversion for Range<const char*>
|
|
*/
|
|
template <class T, class U>
|
|
std::enable_if_t<detail::ComparableAsStringPiece<T, U>::value, bool> operator<=(
|
|
const T& lhs,
|
|
const U& rhs) {
|
|
return StringPiece(lhs) <= StringPiece(rhs);
|
|
}
|
|
|
|
/**
|
|
* operator> through conversion for Range<const char*>
|
|
*/
|
|
template <class T, class U>
|
|
std::enable_if_t<detail::ComparableAsStringPiece<T, U>::value, bool> operator>=(
|
|
const T& lhs,
|
|
const U& rhs) {
|
|
return StringPiece(lhs) >= StringPiece(rhs);
|
|
}
|
|
|
|
/**
|
|
* Finds substrings faster than brute force by borrowing from Boyer-Moore
|
|
*/
|
|
template <class Iter, class Comp>
|
|
size_t qfind(const Range<Iter>& haystack, const Range<Iter>& needle, Comp eq) {
|
|
// Don't use std::search, use a Boyer-Moore-like trick by comparing
|
|
// the last characters first
|
|
auto const nsize = needle.size();
|
|
if (haystack.size() < nsize) {
|
|
return std::string::npos;
|
|
}
|
|
if (!nsize) {
|
|
return 0;
|
|
}
|
|
auto const nsize_1 = nsize - 1;
|
|
auto const lastNeedle = needle[nsize_1];
|
|
|
|
// Boyer-Moore skip value for the last char in the needle. Zero is
|
|
// not a valid value; skip will be computed the first time it's
|
|
// needed.
|
|
std::string::size_type skip = 0;
|
|
|
|
auto i = haystack.begin();
|
|
auto iEnd = haystack.end() - nsize_1;
|
|
|
|
while (i < iEnd) {
|
|
// Boyer-Moore: match the last element in the needle
|
|
while (!eq(i[nsize_1], lastNeedle)) {
|
|
if (++i == iEnd) {
|
|
// not found
|
|
return std::string::npos;
|
|
}
|
|
}
|
|
// Here we know that the last char matches
|
|
// Continue in pedestrian mode
|
|
for (size_t j = 0;;) {
|
|
assert(j < nsize);
|
|
if (!eq(i[j], needle[j])) {
|
|
// Not found, we can skip
|
|
// Compute the skip value lazily
|
|
if (skip == 0) {
|
|
skip = 1;
|
|
while (skip <= nsize_1 && !eq(needle[nsize_1 - skip], lastNeedle)) {
|
|
++skip;
|
|
}
|
|
}
|
|
i += skip;
|
|
break;
|
|
}
|
|
// Check if done searching
|
|
if (++j == nsize) {
|
|
// Yay
|
|
return size_t(i - haystack.begin());
|
|
}
|
|
}
|
|
}
|
|
return std::string::npos;
|
|
}
|
|
|
|
namespace detail {
|
|
|
|
inline size_t qfind_first_byte_of(
|
|
const StringPiece haystack,
|
|
const StringPiece needles) {
|
|
static auto const qfind_first_byte_of_fn = folly::CpuId().sse42()
|
|
? qfind_first_byte_of_sse42
|
|
: qfind_first_byte_of_nosse;
|
|
return qfind_first_byte_of_fn(haystack, needles);
|
|
}
|
|
|
|
} // namespace detail
|
|
|
|
template <class Iter, class Comp>
|
|
size_t qfind_first_of(
|
|
const Range<Iter>& haystack,
|
|
const Range<Iter>& needles,
|
|
Comp eq) {
|
|
auto ret = std::find_first_of(
|
|
haystack.begin(), haystack.end(), needles.begin(), needles.end(), eq);
|
|
return ret == haystack.end() ? std::string::npos : ret - haystack.begin();
|
|
}
|
|
|
|
struct AsciiCaseSensitive {
|
|
bool operator()(char lhs, char rhs) const {
|
|
return lhs == rhs;
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Check if two ascii characters are case insensitive equal.
|
|
* The difference between the lower/upper case characters are the 6-th bit.
|
|
* We also check they are alpha chars, in case of xor = 32.
|
|
*/
|
|
struct AsciiCaseInsensitive {
|
|
bool operator()(char lhs, char rhs) const {
|
|
char k = lhs ^ rhs;
|
|
if (k == 0) {
|
|
return true;
|
|
}
|
|
if (k != 32) {
|
|
return false;
|
|
}
|
|
k = lhs | rhs;
|
|
return (k >= 'a' && k <= 'z');
|
|
}
|
|
};
|
|
|
|
template <class Iter>
|
|
size_t qfind(
|
|
const Range<Iter>& haystack,
|
|
const typename Range<Iter>::value_type& needle) {
|
|
auto pos = std::find(haystack.begin(), haystack.end(), needle);
|
|
return pos == haystack.end() ? std::string::npos : pos - haystack.data();
|
|
}
|
|
|
|
template <class Iter>
|
|
size_t rfind(
|
|
const Range<Iter>& haystack,
|
|
const typename Range<Iter>::value_type& needle) {
|
|
for (auto i = haystack.size(); i-- > 0;) {
|
|
if (haystack[i] == needle) {
|
|
return i;
|
|
}
|
|
}
|
|
return std::string::npos;
|
|
}
|
|
|
|
// specialization for StringPiece
|
|
template <>
|
|
inline size_t qfind(const Range<const char*>& haystack, const char& needle) {
|
|
// memchr expects a not-null pointer, early return if the range is empty.
|
|
if (haystack.empty()) {
|
|
return std::string::npos;
|
|
}
|
|
auto pos = static_cast<const char*>(
|
|
::memchr(haystack.data(), needle, haystack.size()));
|
|
return pos == nullptr ? std::string::npos : pos - haystack.data();
|
|
}
|
|
|
|
template <>
|
|
inline size_t rfind(const Range<const char*>& haystack, const char& needle) {
|
|
// memchr expects a not-null pointer, early return if the range is empty.
|
|
if (haystack.empty()) {
|
|
return std::string::npos;
|
|
}
|
|
auto pos = static_cast<const char*>(
|
|
::memrchr(haystack.data(), needle, haystack.size()));
|
|
return pos == nullptr ? std::string::npos : pos - haystack.data();
|
|
}
|
|
|
|
// specialization for ByteRange
|
|
template <>
|
|
inline size_t qfind(
|
|
const Range<const unsigned char*>& haystack,
|
|
const unsigned char& needle) {
|
|
// memchr expects a not-null pointer, early return if the range is empty.
|
|
if (haystack.empty()) {
|
|
return std::string::npos;
|
|
}
|
|
auto pos = static_cast<const unsigned char*>(
|
|
::memchr(haystack.data(), needle, haystack.size()));
|
|
return pos == nullptr ? std::string::npos : pos - haystack.data();
|
|
}
|
|
|
|
template <>
|
|
inline size_t rfind(
|
|
const Range<const unsigned char*>& haystack,
|
|
const unsigned char& needle) {
|
|
// memchr expects a not-null pointer, early return if the range is empty.
|
|
if (haystack.empty()) {
|
|
return std::string::npos;
|
|
}
|
|
auto pos = static_cast<const unsigned char*>(
|
|
::memrchr(haystack.data(), needle, haystack.size()));
|
|
return pos == nullptr ? std::string::npos : pos - haystack.data();
|
|
}
|
|
|
|
template <class Iter>
|
|
size_t qfind_first_of(const Range<Iter>& haystack, const Range<Iter>& needles) {
|
|
return qfind_first_of(haystack, needles, AsciiCaseSensitive());
|
|
}
|
|
|
|
// specialization for StringPiece
|
|
template <>
|
|
inline size_t qfind_first_of(
|
|
const Range<const char*>& haystack,
|
|
const Range<const char*>& needles) {
|
|
return detail::qfind_first_byte_of(haystack, needles);
|
|
}
|
|
|
|
// specialization for ByteRange
|
|
template <>
|
|
inline size_t qfind_first_of(
|
|
const Range<const unsigned char*>& haystack,
|
|
const Range<const unsigned char*>& needles) {
|
|
return detail::qfind_first_byte_of(
|
|
StringPiece(haystack), StringPiece(needles));
|
|
}
|
|
|
|
template <class Key, class Enable>
|
|
struct hasher;
|
|
|
|
template <class T>
|
|
struct hasher<
|
|
folly::Range<T*>,
|
|
std::enable_if_t<std::is_integral<T>::value, void>> {
|
|
using folly_is_avalanching = std::true_type;
|
|
|
|
size_t operator()(folly::Range<T*> r) const {
|
|
// std::is_integral<T> is too restrictive, but is sufficient to
|
|
// guarantee we can just hash all of the underlying bytes to get a
|
|
// suitable hash of T. Something like absl::is_uniquely_represented<T>
|
|
// would be better. std::is_pod is not enough, because POD types
|
|
// can contain pointers and padding. Also, floating point numbers
|
|
// may be == without being bit-identical.
|
|
return hash::SpookyHashV2::Hash64(r.begin(), r.size() * sizeof(T), 0);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* _sp is a user-defined literal suffix to make an appropriate Range
|
|
* specialization from a literal string.
|
|
*
|
|
* Modeled after C++17's `sv` suffix.
|
|
*/
|
|
inline namespace literals {
|
|
inline namespace string_piece_literals {
|
|
constexpr Range<char const*> operator"" _sp(
|
|
char const* str,
|
|
size_t len) noexcept {
|
|
return Range<char const*>(str, len);
|
|
}
|
|
|
|
constexpr Range<char16_t const*> operator"" _sp(
|
|
char16_t const* str,
|
|
size_t len) noexcept {
|
|
return Range<char16_t const*>(str, len);
|
|
}
|
|
|
|
constexpr Range<char32_t const*> operator"" _sp(
|
|
char32_t const* str,
|
|
size_t len) noexcept {
|
|
return Range<char32_t const*>(str, len);
|
|
}
|
|
|
|
constexpr Range<wchar_t const*> operator"" _sp(
|
|
wchar_t const* str,
|
|
size_t len) noexcept {
|
|
return Range<wchar_t const*>(str, len);
|
|
}
|
|
} // namespace string_piece_literals
|
|
} // namespace literals
|
|
|
|
} // namespace folly
|
|
|
|
FOLLY_POP_WARNING
|
|
|
|
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(folly::Range)
|