/*
- * Copyright 2012 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
// @author Mark Rabkin (mrabkin@fb.com)
// @author Andrei Alexandrescu (andrei.alexandrescu@fb.com)
-#ifndef FOLLY_RANGE_H_
-#define FOLLY_RANGE_H_
+#pragma once
-#include "folly/FBString.h"
+#include <folly/FBString.h>
+#include <folly/Portability.h>
+#include <folly/SpookyHashV2.h>
+#include <folly/portability/BitsFunctexcept.h>
+#include <folly/portability/Constexpr.h>
+#include <folly/portability/String.h>
+
+#include <boost/operators.hpp>
#include <glog/logging.h>
#include <algorithm>
+#include <array>
+#include <climits>
+#include <cstddef>
#include <cstring>
-#include <iostream>
-#include <string>
+#include <iosfwd>
#include <stdexcept>
+#include <string>
#include <type_traits>
-#include <boost/operators.hpp>
-#include <boost/utility/enable_if.hpp>
-#include <boost/type_traits.hpp>
+
+// libc++ doesn't provide this header, nor does msvc
+#ifdef FOLLY_HAVE_BITS_CXXCONFIG_H
+// This file appears in two locations: inside fbcode and in the
+// libstdc++ source code (when embedding fbstring as std::string).
+// To aid in this schizophrenic use, two macros are defined in
+// c++config.h:
+// _LIBSTDCXX_FBSTRING - Set inside libstdc++. This is useful to
+// gate use inside fbcode v. libstdc++
#include <bits/c++config.h>
-#include "folly/Traits.h"
+#endif
+
+#include <folly/CpuId.h>
+#include <folly/Traits.h>
+#include <folly/Likely.h>
+#include <folly/detail/RangeCommon.h>
+#include <folly/detail/RangeSse42.h>
+
+// Ignore shadowing warnings within this file, so includers can use -Wshadow.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wshadow"
namespace folly {
-template <class T> class Range;
+template <class Iter> class Range;
/**
* Finds the first occurrence of needle in haystack. The algorithm is on
* as Boyer-Moore. On the upside, it does not do any upfront
* preprocessing and does not allocate memory.
*/
-template <class T>
-inline size_t qfind(const Range<T> & haystack,
- const Range<T> & needle);
+template <class Iter,
+ class Comp = std::equal_to<typename Range<Iter>::value_type>>
+inline size_t qfind(const Range<Iter> & haystack,
+ const Range<Iter> & needle,
+ Comp eq = Comp());
/**
* Finds the first occurrence of needle in haystack. The result is the
* offset reported to the beginning of haystack, or string::npos if
* needle wasn't found.
*/
-template <class T>
-size_t qfind(const Range<T> & haystack,
- const typename Range<T>::value_type& needle);
+template <class Iter>
+size_t qfind(const Range<Iter> & haystack,
+ const typename Range<Iter>::value_type& needle);
+
+/**
+ * Finds the last occurrence of needle in haystack. The result is the
+ * offset reported to the beginning of haystack, or string::npos if
+ * needle wasn't found.
+ */
+template <class Iter>
+size_t rfind(const Range<Iter> & haystack,
+ const typename Range<Iter>::value_type& needle);
/**
* Finds the first occurrence of any element of needle in
* haystack. The algorithm is O(haystack.size() * needle.size()).
*/
-template <class T>
-inline size_t qfind_first_of(const Range<T> & haystack,
- const Range<T> & needle);
+template <class Iter>
+inline size_t qfind_first_of(const Range<Iter> & haystack,
+ const Range<Iter> & needle);
/**
* Small internal helper - returns the value just before an iterator.
* For random-access iterators, the value before is simply i[-1].
*/
template <class Iter>
-typename boost::enable_if_c<
- boost::is_same<typename std::iterator_traits<Iter>::iterator_category,
- std::random_access_iterator_tag>::value,
+typename std::enable_if<
+ std::is_same<typename std::iterator_traits<Iter>::iterator_category,
+ std::random_access_iterator_tag>::value,
typename std::iterator_traits<Iter>::reference>::type
value_before(Iter i) {
return i[-1];
* For all other iterators, we need to use the decrement operator.
*/
template <class Iter>
-typename boost::enable_if_c<
- !boost::is_same<typename std::iterator_traits<Iter>::iterator_category,
- std::random_access_iterator_tag>::value,
+typename std::enable_if<
+ !std::is_same<typename std::iterator_traits<Iter>::iterator_category,
+ std::random_access_iterator_tag>::value,
typename std::iterator_traits<Iter>::reference>::type
value_before(Iter i) {
return *--i;
}
+/*
+ * Use IsCharPointer<T>::type to enable const char* or char*.
+ * Use IsCharPointer<T>::const_type to enable only const char*.
+ */
+template <class T> struct IsCharPointer {};
+
+template <>
+struct IsCharPointer<char*> {
+ typedef int type;
+};
+
+template <>
+struct IsCharPointer<const char*> {
+ typedef int const_type;
+ typedef int type;
+};
+
} // namespace detail
/**
typedef std::size_t size_type;
typedef Iter iterator;
typedef Iter const_iterator;
- typedef typename boost::remove_reference<
+ typedef typename std::remove_reference<
typename std::iterator_traits<Iter>::reference>::type
value_type;
+ using difference_type = typename std::iterator_traits<Iter>::difference_type;
typedef typename std::iterator_traits<Iter>::reference reference;
- typedef std::char_traits<value_type> traits_type;
+
+ /**
+ * For MutableStringPiece and MutableByteRange we define StringPiece
+ * and ByteRange as const_range_type (for everything else its just
+ * identity). We do that to enable operations such as find with
+ * args which are const.
+ */
+ typedef typename std::conditional<
+ std::is_same<Iter, char*>::value
+ || std::is_same<Iter, unsigned char*>::value,
+ Range<const value_type*>,
+ Range<Iter>>::type const_range_type;
+
+ typedef std::char_traits<typename std::remove_const<value_type>::type>
+ traits_type;
static const size_type npos;
// Works for all iterators
- Range() : b_(), e_() {
+ constexpr Range() : b_(), e_() {
}
-private:
- static bool reachable(Iter b, Iter e, std::forward_iterator_tag) {
- for (; b != e; ++b) {
- LOG_EVERY_N(INFO, 100000) << __FILE__ ":" << __LINE__
- << " running reachability test ("
- << google::COUNTER << " iterations)...";
- }
- return true;
- }
-
- static bool reachable(Iter b, Iter e, std::random_access_iterator_tag) {
- return b <= e;
- }
+ constexpr Range(const Range&) = default;
+ constexpr Range(Range&&) = default;
public:
// Works for all iterators
- Range(Iter start, Iter end)
- : b_(start), e_(end) {
- assert(reachable(b_, e_,
- typename std::iterator_traits<Iter>::iterator_category()));
+ constexpr Range(Iter start, Iter end) : b_(start), e_(end) {
}
// Works only for random-access iterators
- Range(Iter start, size_t size)
+ constexpr Range(Iter start, size_t size)
: b_(start), e_(start + size) { }
- // Works only for Range<const char*>
- /* implicit */ Range(Iter str)
- : b_(str), e_(b_ + strlen(str)) {}
- // Works only for Range<const char*>
+ /* implicit */ Range(std::nullptr_t) = delete;
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::type = 0>
+ constexpr /* implicit */ Range(Iter str)
+ : b_(str), e_(str + constexpr_strlen(str)) {}
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
/* implicit */ Range(const std::string& str)
: b_(str.data()), e_(b_ + str.size()) {}
- // Works only for Range<const char*>
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
Range(const std::string& str, std::string::size_type startFrom) {
- CHECK_LE(startFrom, str.size());
+ if (UNLIKELY(startFrom > str.size())) {
+ std::__throw_out_of_range("index out of range");
+ }
b_ = str.data() + startFrom;
e_ = str.data() + str.size();
}
- // Works only for Range<const char*>
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
Range(const std::string& str,
std::string::size_type startFrom,
std::string::size_type size) {
- CHECK_LE(startFrom + size, str.size());
+ if (UNLIKELY(startFrom > str.size())) {
+ std::__throw_out_of_range("index out of range");
+ }
b_ = str.data() + startFrom;
- e_ = b_ + size;
- }
- Range(const Range<Iter>& str,
- size_t startFrom,
- size_t size) {
- CHECK_LE(startFrom + size, str.size());
- b_ = str.b_ + startFrom;
- e_ = b_ + size;
+ if (str.size() - startFrom < size) {
+ e_ = str.data() + str.size();
+ } else {
+ e_ = b_ + size;
+ }
}
- // Works only for Range<const char*>
+
+ Range(const Range& other,
+ size_type first,
+ size_type length = npos)
+ : Range(other.subpiece(first, length))
+ { }
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
/* implicit */ Range(const fbstring& str)
: b_(str.data()), e_(b_ + str.size()) { }
- // Works only for Range<const char*>
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
Range(const fbstring& str, fbstring::size_type startFrom) {
- CHECK_LE(startFrom, str.size());
+ if (UNLIKELY(startFrom > str.size())) {
+ std::__throw_out_of_range("index out of range");
+ }
b_ = str.data() + startFrom;
e_ = str.data() + str.size();
}
- // Works only for Range<const char*>
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
Range(const fbstring& str, fbstring::size_type startFrom,
fbstring::size_type size) {
- CHECK_LE(startFrom + size, str.size());
+ if (UNLIKELY(startFrom > str.size())) {
+ std::__throw_out_of_range("index out of range");
+ }
b_ = str.data() + startFrom;
- e_ = b_ + size;
+ if (str.size() - startFrom < size) {
+ e_ = str.data() + str.size();
+ } else {
+ e_ = b_ + size;
+ }
}
// Allow implicit conversion from Range<const char*> (aka StringPiece) to
// direction.
template <class OtherIter, typename std::enable_if<
(std::is_same<Iter, const unsigned char*>::value &&
- std::is_same<OtherIter, const char*>::value), int>::type = 0>
+ (std::is_same<OtherIter, const char*>::value ||
+ std::is_same<OtherIter, char*>::value)), int>::type = 0>
/* implicit */ Range(const Range<OtherIter>& other)
: b_(reinterpret_cast<const unsigned char*>(other.begin())),
e_(reinterpret_cast<const unsigned char*>(other.end())) {
}
+ template <class OtherIter, typename std::enable_if<
+ (std::is_same<Iter, unsigned char*>::value &&
+ std::is_same<OtherIter, char*>::value), int>::type = 0>
+ /* implicit */ Range(const Range<OtherIter>& other)
+ : b_(reinterpret_cast<unsigned char*>(other.begin())),
+ e_(reinterpret_cast<unsigned char*>(other.end())) {
+ }
+
template <class OtherIter, typename std::enable_if<
(std::is_same<Iter, const char*>::value &&
- std::is_same<OtherIter, const unsigned char*>::value), int>::type = 0>
+ (std::is_same<OtherIter, const unsigned char*>::value ||
+ std::is_same<OtherIter, unsigned char*>::value)), int>::type = 0>
explicit Range(const Range<OtherIter>& other)
: b_(reinterpret_cast<const char*>(other.begin())),
e_(reinterpret_cast<const char*>(other.end())) {
}
+ template <class OtherIter, typename std::enable_if<
+ (std::is_same<Iter, char*>::value &&
+ std::is_same<OtherIter, unsigned char*>::value), int>::type = 0>
+ explicit Range(const Range<OtherIter>& other)
+ : b_(reinterpret_cast<char*>(other.begin())),
+ e_(reinterpret_cast<char*>(other.end())) {
+ }
+
+ // Allow implicit conversion from Range<From> to Range<To> if From is
+ // implicitly convertible to To.
+ template <class OtherIter, typename std::enable_if<
+ (!std::is_same<Iter, OtherIter>::value &&
+ std::is_convertible<OtherIter, Iter>::value), int>::type = 0>
+ constexpr /* implicit */ Range(const Range<OtherIter>& other)
+ : b_(other.begin()),
+ e_(other.end()) {
+ }
+
+ // Allow explicit conversion from Range<From> to Range<To> if From is
+ // explicitly convertible to To.
+ template <class OtherIter, typename std::enable_if<
+ (!std::is_same<Iter, OtherIter>::value &&
+ !std::is_convertible<OtherIter, Iter>::value &&
+ std::is_constructible<Iter, const OtherIter&>::value), int>::type = 0>
+ constexpr explicit Range(const Range<OtherIter>& other)
+ : b_(other.begin()),
+ e_(other.end()) {
+ }
+
+ /**
+ * Allow explicit construction of Range() from a std::array of a
+ * convertible type.
+ *
+ * For instance, this allows constructing StringPiece from a
+ * std::array<char, N> or a std::array<const char, N>
+ */
+ template <
+ class T,
+ size_t N,
+ typename = typename std::enable_if<
+ std::is_convertible<const T*, Iter>::value>::type>
+ constexpr explicit Range(const std::array<T, N>& array)
+ : b_{array.empty() ? nullptr : &array.at(0)},
+ e_{array.empty() ? nullptr : &array.at(0) + N} {}
+ template <
+ class T,
+ size_t N,
+ typename =
+ typename std::enable_if<std::is_convertible<T*, Iter>::value>::type>
+ constexpr explicit Range(std::array<T, N>& array)
+ : b_{array.empty() ? nullptr : &array.at(0)},
+ e_{array.empty() ? nullptr : &array.at(0) + N} {}
+
+ Range& operator=(const Range& rhs) & = default;
+ Range& operator=(Range&& rhs) & = default;
+
+ template <class T = Iter, typename detail::IsCharPointer<T>::const_type = 0>
+ Range& operator=(std::string&& rhs) = delete;
+
void clear() {
b_ = Iter();
e_ = Iter();
reset(str.data(), str.size());
}
- size_type size() const {
- assert(b_ <= e_);
- return e_ - b_;
+ constexpr size_type size() const {
+ // It would be nice to assert(b_ <= e_) here. This can be achieved even
+ // in a C++11 compatible constexpr function:
+ // http://ericniebler.com/2014/09/27/assert-and-constexpr-in-cxx11/
+ // Unfortunately current gcc versions have a bug causing it to reject
+ // this check in a constexpr function:
+ // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71448
+ return size_type(e_ - b_);
+ }
+ constexpr size_type walk_size() const {
+ return size_type(std::distance(b_, e_));
}
- size_type walk_size() const {
- assert(b_ <= e_);
- return std::distance(b_, e_);
+ constexpr bool empty() const {
+ return b_ == e_;
+ }
+ constexpr Iter data() const {
+ return b_;
+ }
+ constexpr Iter start() const {
+ return b_;
+ }
+ constexpr Iter begin() const {
+ return b_;
+ }
+ constexpr Iter end() const {
+ return e_;
+ }
+ constexpr Iter cbegin() const {
+ return b_;
+ }
+ constexpr Iter cend() const {
+ return e_;
}
- bool empty() const { return b_ == e_; }
- Iter data() const { return b_; }
- Iter start() const { return b_; }
- Iter begin() const { return b_; }
- Iter end() const { return e_; }
- Iter cbegin() const { return b_; }
- Iter cend() const { return e_; }
value_type& front() {
assert(b_ < e_);
return *b_;
assert(b_ < e_);
return detail::value_before(e_);
}
- // Works only for Range<const char*>
+ // Works only for Range<const char*> and Range<char*>
std::string str() const { return std::string(b_, size()); }
std::string toString() const { return str(); }
- // Works only for Range<const char*>
+ // Works only for Range<const char*> and Range<char*>
fbstring fbstr() const { return fbstring(b_, size()); }
fbstring toFbstring() const { return fbstr(); }
- // Works only for Range<const char*>
- int compare(const Range& o) const {
+ const_range_type castToConst() const {
+ return const_range_type(*this);
+ }
+
+ // Works only for Range<const char*> and Range<char*>
+ 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) r = tsize - osize;
+ 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) {
- CHECK_GT(size(), i);
+ DCHECK_GT(size(), i);
return b_[i];
}
const value_type& operator[](size_t i) const {
- CHECK_GT(size(), i);
+ DCHECK_GT(size(), i);
return b_[i];
}
value_type& at(size_t i) {
- if (i >= size()) throw std::out_of_range("index out of range");
+ if (i >= size()) std::__throw_out_of_range("index out of range");
return b_[i];
}
const value_type& at(size_t i) const {
- if (i >= size()) throw std::out_of_range("index out of range");
+ if (i >= size()) std::__throw_out_of_range("index out of range");
return b_[i];
}
- // Works only for Range<const char*>
+ // 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
+ FOLLY_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
}
void advance(size_type n) {
- CHECK_LE(n, size());
+ if (UNLIKELY(n > size())) {
+ std::__throw_out_of_range("index out of range");
+ }
b_ += n;
}
void subtract(size_type n) {
- CHECK_LE(n, size());
+ if (UNLIKELY(n > size())) {
+ std::__throw_out_of_range("index out of range");
+ }
+ e_ -= n;
+ }
+
+ Range subpiece(size_type first, size_type length = npos) const {
+ if (UNLIKELY(first > size())) {
+ std::__throw_out_of_range("index out of range");
+ }
+
+ return Range(b_ + first, std::min(length, size() - first));
+ }
+
+ // unchecked versions
+ void uncheckedAdvance(size_type n) {
+ DCHECK_LE(n, size());
+ b_ += n;
+ }
+
+ void uncheckedSubtract(size_type n) {
+ DCHECK_LE(n, size());
e_ -= n;
}
+ Range uncheckedSubpiece(size_type first, size_type length = npos) const {
+ DCHECK_LE(first, size());
+ return Range(b_ + first, std::min(length, size() - first));
+ }
+
void pop_front() {
assert(b_ < e_);
++b_;
--e_;
}
- Range subpiece(size_type first,
- size_type length = std::string::npos) const {
- CHECK_LE(first, size());
- return Range(b_ + first,
- std::min<std::string::size_type>(length, size() - first));
- }
-
// string work-alike functions
- size_type find(Range str) const {
- return qfind(*this, str);
+ size_type find(const_range_type str) const {
+ return qfind(castToConst(), str);
}
- size_type find(Range str, size_t pos) const {
+ size_type find(const_range_type str, size_t pos) const {
if (pos > size()) return std::string::npos;
- size_t ret = qfind(subpiece(pos), str);
+ 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;
- size_t ret = qfind(pos ? subpiece(pos) : *this, Range(s, n));
+ 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
+ // Works only for Range<(const) (unsigned) char*> which have Range(Iter) ctor
size_type find(const Iter s) const {
- return qfind(*this, Range(s));
+ return qfind(castToConst(), const_range_type(s));
}
- // Works only for Range<const (unsigned) char*> which have Range(Iter) ctor
+ // 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(subpiece(pos), Range(s));
+ 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(*this, c);
+ 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(subpiece(pos), c);
+ size_type ret = qfind(castToConst().subpiece(pos), c);
return ret == npos ? ret : ret + pos;
}
- size_type find_first_of(Range needles) const {
- return qfind_first_of(*this, needles);
+ size_type find_first_of(const_range_type needles) const {
+ return qfind_first_of(castToConst(), needles);
}
- size_type find_first_of(Range needles, size_t pos) const {
+ 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(pos ? subpiece(pos) : *this, needles);
+ 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
+ // Works only for Range<(const) (unsigned) char*> which have Range(Iter) ctor
size_type find_first_of(Iter needles) const {
- return find_first_of(Range(needles));
+ return find_first_of(const_range_type(needles));
}
- // Works only for Range<const (unsigned) char*> which have Range(Iter) ctor
+ // 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(Range(needles), pos);
+ 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(Range(needles, n), pos);
+ return find_first_of(const_range_type(needles, n), pos);
}
size_type find_first_of(value_type c) 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));
+ }
+
+ /**
+ * 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 {
+ std::__throw_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 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 T>
-void swap(Range<T>& lhs, Range<T>& rhs) {
+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>
-Range<Iter> makeRange(Iter first, Iter last) {
+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,
+ class T = typename std::remove_pointer<
+ decltype(std::declval<Collection>().data())>::type>
+constexpr Range<T*> range(Collection&& v) {
+ return Range<T*>(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<const T*> range(const std::array<T, n>& array) {
+ return Range<const T*>{array};
+}
+
typedef Range<const char*> StringPiece;
+typedef Range<char*> MutableStringPiece;
typedef Range<const unsigned char*> ByteRange;
+typedef Range<unsigned char*> MutableByteRange;
+
+inline std::ostream& operator<<(std::ostream& os,
+ const StringPiece piece) {
+ os.write(piece.start(), std::streamsize(piece.size()));
+ return os;
+}
-std::ostream& operator<<(std::ostream& os, const StringPiece& piece);
+inline std::ostream& operator<<(std::ostream& os,
+ const MutableStringPiece piece) {
+ os.write(piece.start(), std::streamsize(piece.size()));
+ return os;
+}
/**
* Templated comparison operators
*/
-template <class T>
-inline bool operator==(const Range<T>& lhs, const Range<T>& rhs) {
+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 T>
-inline bool operator<(const Range<T>& lhs, const Range<T>& rhs) {
+template <class Iter>
+inline bool operator<(const Range<Iter>& lhs, const Range<Iter>& rhs) {
return lhs.compare(rhs) < 0;
}
struct ComparableAsStringPiece {
enum {
value =
- (
boost::is_convertible<A, StringPiece>::value
- && boost::is_same<B, StringPiece>::value)
+ (
std::is_convertible<A, StringPiece>::value
+ && std::is_same<B, StringPiece>::value)
||
- (boost::is_convertible<B, StringPiece>::value
- &&
boost::is_same<A, StringPiece>::value)
+ (std::is_convertible<B, StringPiece>::value
+ &&
std::is_same<A, StringPiece>::value)
};
};
*/
template <class T, class U>
typename
-boost::enable_if_c<detail::ComparableAsStringPiece<T, U>::value, bool>::type
+std::enable_if<detail::ComparableAsStringPiece<T, U>::value, bool>::type
operator==(const T& lhs, const U& rhs) {
return StringPiece(lhs) == StringPiece(rhs);
}
*/
template <class T, class U>
typename
-boost::enable_if_c<detail::ComparableAsStringPiece<T, U>::value, bool>::type
+std::enable_if<detail::ComparableAsStringPiece<T, U>::value, bool>::type
operator<(const T& lhs, const U& rhs) {
return StringPiece(lhs) < StringPiece(rhs);
}
*/
template <class T, class U>
typename
-boost::enable_if_c<detail::ComparableAsStringPiece<T, U>::value, bool>::type
+std::enable_if<detail::ComparableAsStringPiece<T, U>::value, bool>::type
operator>(const T& lhs, const U& rhs) {
return StringPiece(lhs) > StringPiece(rhs);
}
*/
template <class T, class U>
typename
-boost::enable_if_c<detail::ComparableAsStringPiece<T, U>::value, bool>::type
+std::enable_if<detail::ComparableAsStringPiece<T, U>::value, bool>::type
operator<=(const T& lhs, const U& rhs) {
return StringPiece(lhs) <= StringPiece(rhs);
}
*/
template <class T, class U>
typename
-boost::enable_if_c<detail::ComparableAsStringPiece<T, U>::value, bool>::type
+std::enable_if<detail::ComparableAsStringPiece<T, U>::value, bool>::type
operator>=(const T& lhs, const U& rhs) {
return StringPiece(lhs) >= StringPiece(rhs);
}
-struct StringPieceHash {
- std::size_t operator()(const StringPiece& str) const {
- return static_cast<std::size_t>(str.hash());
- }
-};
-
/**
* Finds substrings faster than brute force by borrowing from Boyer-Moore
*/
-template <class T, class Comp>
-size_t qfind(const Range<T>& haystack,
- const Range<T>& needle,
+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
// Check if done searching
if (++j == nsize) {
// Yay
- return i - haystack.begin();
+ return size_t(i - haystack.begin());
}
}
}
return std::string::npos;
}
-template <class T, class Comp>
-size_t qfind_first_of(const Range<T> & haystack,
- const Range<T> & needle,
+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(),
- needle.begin(), needle.end(),
+ needles.begin(), needles.end(),
eq);
return ret == haystack.end() ? std::string::npos : ret - haystack.begin();
}
}
};
+/**
+ * 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 {
- return toupper(lhs) == toupper(rhs);
+ char k = lhs ^ rhs;
+ if (k == 0) return true;
+ if (k != 32) return false;
+ k = lhs | rhs;
+ return (k >= 'a' && k <= 'z');
}
};
-extern const AsciiCaseSensitive asciiCaseSensitive;
-extern const AsciiCaseInsensitive asciiCaseInsensitive;
-
-template <class T>
-size_t qfind(const Range<T>& haystack,
- const Range<T>& needle) {
- return qfind(haystack, needle, asciiCaseSensitive);
-}
-
-template <class T>
-size_t qfind(const Range<T>& haystack,
- const typename Range<T>::value_type& needle) {
+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 <class T>
-size_t qfind_first_of(const Range<T>& haystack,
- const Range<T>& needle) {
- return qfind_first_of(haystack, needle, asciiCaseSensitive);
+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*>,
+ typename std::enable_if<std::is_pod<T>::value, void>::type> {
+ size_t operator()(folly::Range<T*> r) const {
+ return hash::SpookyHashV2::Hash64(r.begin(), r.size() * sizeof(T), 0);
+ }
+};
+
+/**
+ * Ubiquitous helper template for knowing what's a string
+ */
+template <class T> struct IsSomeString {
+ enum { value = std::is_same<T, std::string>::value
+ || std::is_same<T, fbstring>::value };
+};
+
} // !namespace folly
-FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(folly::Range);
+#pragma GCC diagnostic pop
-#endif // FOLLY_RANGE_H_
+FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(folly::Range);
projects / folly.git / blobdiff