nghttp2/src/template.h

549 lines
16 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2015 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef TEMPLATE_H
#define TEMPLATE_H
#include "nghttp2_config.h"
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <memory>
#include <array>
#include <functional>
#include <typeinfo>
#include <algorithm>
#include <ostream>
#include <utility>
namespace nghttp2 {
// std::forward is constexpr since C++14
template <typename... T>
constexpr std::array<
typename std::decay<typename std::common_type<T...>::type>::type,
sizeof...(T)>
make_array(T &&... t) {
return std::array<
typename std::decay<typename std::common_type<T...>::type>::type,
sizeof...(T)>{{std::forward<T>(t)...}};
}
template <typename T, size_t N> constexpr size_t array_size(T (&)[N]) {
return N;
}
template <typename T, size_t N> constexpr size_t str_size(T (&)[N]) {
return N - 1;
}
// inspired by <http://blog.korfuri.fr/post/go-defer-in-cpp/>, but our
// template can take functions returning other than void.
template <typename F, typename... T> struct Defer {
Defer(F &&f, T &&... t)
: f(std::bind(std::forward<F>(f), std::forward<T>(t)...)) {}
Defer(Defer &&o) noexcept : f(std::move(o.f)) {}
~Defer() { f(); }
using ResultType = typename std::result_of<typename std::decay<F>::type(
typename std::decay<T>::type...)>::type;
std::function<ResultType()> f;
};
template <typename F, typename... T> Defer<F, T...> defer(F &&f, T &&... t) {
return Defer<F, T...>(std::forward<F>(f), std::forward<T>(t)...);
}
template <typename T, typename F> bool test_flags(T t, F flags) {
return (t & flags) == flags;
}
// doubly linked list of element T*. T must have field T *dlprev and
// T *dlnext, which point to previous element and next element in the
// list respectively.
template <typename T> struct DList {
DList() : head(nullptr), tail(nullptr), len(0) {}
DList(const DList &) = delete;
DList &operator=(const DList &) = delete;
DList(DList &&other) noexcept
: head{std::exchange(other.head, nullptr)},
tail{std::exchange(other.tail, nullptr)},
len{std::exchange(other.len, 0)} {}
DList &operator=(DList &&other) noexcept {
if (this == &other) {
return *this;
}
head = std::exchange(other.head, nullptr);
tail = std::exchange(other.tail, nullptr);
len = std::exchange(other.len, 0);
return *this;
}
void append(T *t) {
++len;
if (tail) {
tail->dlnext = t;
t->dlprev = tail;
tail = t;
return;
}
head = tail = t;
}
void remove(T *t) {
--len;
auto p = t->dlprev;
auto n = t->dlnext;
if (p) {
p->dlnext = n;
}
if (head == t) {
head = n;
}
if (n) {
n->dlprev = p;
}
if (tail == t) {
tail = p;
}
t->dlprev = t->dlnext = nullptr;
}
bool empty() const { return head == nullptr; }
size_t size() const { return len; }
T *head, *tail;
size_t len;
};
template <typename T> void dlist_delete_all(DList<T> &dl) {
for (auto e = dl.head; e;) {
auto next = e->dlnext;
delete e;
e = next;
}
}
// User-defined literals for K, M, and G (powers of 1024)
constexpr unsigned long long operator"" _k(unsigned long long k) {
return k * 1024;
}
constexpr unsigned long long operator"" _m(unsigned long long m) {
return m * 1024 * 1024;
}
constexpr unsigned long long operator"" _g(unsigned long long g) {
return g * 1024 * 1024 * 1024;
}
// User-defined literals for time, converted into double in seconds
// hours
constexpr double operator"" _h(unsigned long long h) { return h * 60 * 60; }
// minutes
constexpr double operator"" _min(unsigned long long min) { return min * 60; }
// seconds
constexpr double operator"" _s(unsigned long long s) { return s; }
// milliseconds
constexpr double operator"" _ms(unsigned long long ms) { return ms / 1000.; }
// Returns a copy of NULL-terminated string [first, last).
template <typename InputIt>
std::unique_ptr<char[]> strcopy(InputIt first, InputIt last) {
auto res = std::make_unique<char[]>(last - first + 1);
*std::copy(first, last, res.get()) = '\0';
return res;
}
// Returns a copy of NULL-terminated string |val|.
inline std::unique_ptr<char[]> strcopy(const char *val) {
return strcopy(val, val + strlen(val));
}
inline std::unique_ptr<char[]> strcopy(const char *val, size_t n) {
return strcopy(val, val + n);
}
// Returns a copy of val.c_str().
inline std::unique_ptr<char[]> strcopy(const std::string &val) {
return strcopy(std::begin(val), std::end(val));
}
inline std::unique_ptr<char[]> strcopy(const std::unique_ptr<char[]> &val) {
if (!val) {
return nullptr;
}
return strcopy(val.get());
}
inline std::unique_ptr<char[]> strcopy(const std::unique_ptr<char[]> &val,
size_t n) {
if (!val) {
return nullptr;
}
return strcopy(val.get(), val.get() + n);
}
// ImmutableString represents string that is immutable unlike
// std::string. It has c_str() and size() functions to mimic
// std::string. It manages buffer by itself. Just like std::string,
// c_str() returns NULL-terminated string, but NULL character may
// appear before the final terminal NULL.
class ImmutableString {
public:
using traits_type = std::char_traits<char>;
using value_type = traits_type::char_type;
using allocator_type = std::allocator<char>;
using size_type = std::allocator_traits<allocator_type>::size_type;
using difference_type =
std::allocator_traits<allocator_type>::difference_type;
using const_reference = const value_type &;
using const_pointer = const value_type *;
using const_iterator = const_pointer;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
ImmutableString() : len(0), base("") {}
ImmutableString(const char *s, size_t slen)
: len(slen), base(copystr(s, s + len)) {}
explicit ImmutableString(const char *s)
: len(strlen(s)), base(copystr(s, s + len)) {}
explicit ImmutableString(const std::string &s)
: len(s.size()), base(copystr(std::begin(s), std::end(s))) {}
template <typename InputIt>
ImmutableString(InputIt first, InputIt last)
: len(std::distance(first, last)), base(copystr(first, last)) {}
ImmutableString(const ImmutableString &other)
: len(other.len), base(copystr(std::begin(other), std::end(other))) {}
ImmutableString(ImmutableString &&other) noexcept
: len{std::exchange(other.len, 0)}, base{std::exchange(other.base, "")} {}
~ImmutableString() {
if (len) {
delete[] base;
}
}
ImmutableString &operator=(const ImmutableString &other) {
if (this == &other) {
return *this;
}
if (len) {
delete[] base;
}
len = other.len;
base = copystr(std::begin(other), std::end(other));
return *this;
}
ImmutableString &operator=(ImmutableString &&other) noexcept {
if (this == &other) {
return *this;
}
if (len) {
delete[] base;
}
len = std::exchange(other.len, 0);
base = std::exchange(other.base, "");
return *this;
}
template <size_t N> static ImmutableString from_lit(const char (&s)[N]) {
return ImmutableString(s, N - 1);
}
const_iterator begin() const { return base; };
const_iterator cbegin() const { return base; };
const_iterator end() const { return base + len; };
const_iterator cend() const { return base + len; };
const_reverse_iterator rbegin() const {
return const_reverse_iterator{base + len};
}
const_reverse_iterator crbegin() const {
return const_reverse_iterator{base + len};
}
const_reverse_iterator rend() const { return const_reverse_iterator{base}; }
const_reverse_iterator crend() const { return const_reverse_iterator{base}; }
const char *c_str() const { return base; }
size_type size() const { return len; }
bool empty() const { return len == 0; }
const_reference operator[](size_type pos) const { return *(base + pos); }
private:
template <typename InputIt> const char *copystr(InputIt first, InputIt last) {
if (first == last) {
return "";
}
auto res = new char[std::distance(first, last) + 1];
*std::copy(first, last, res) = '\0';
return res;
}
size_type len;
const char *base;
};
inline bool operator==(const ImmutableString &lhs, const ImmutableString &rhs) {
return lhs.size() == rhs.size() &&
std::equal(std::begin(lhs), std::end(lhs), std::begin(rhs));
}
inline bool operator==(const ImmutableString &lhs, const std::string &rhs) {
return lhs.size() == rhs.size() &&
std::equal(std::begin(lhs), std::end(lhs), std::begin(rhs));
}
inline bool operator==(const std::string &lhs, const ImmutableString &rhs) {
return rhs == lhs;
}
inline bool operator==(const ImmutableString &lhs, const char *rhs) {
return lhs.size() == strlen(rhs) &&
std::equal(std::begin(lhs), std::end(lhs), rhs);
}
inline bool operator==(const char *lhs, const ImmutableString &rhs) {
return rhs == lhs;
}
inline bool operator!=(const ImmutableString &lhs, const ImmutableString &rhs) {
return !(lhs == rhs);
}
inline bool operator!=(const ImmutableString &lhs, const std::string &rhs) {
return !(lhs == rhs);
}
inline bool operator!=(const std::string &lhs, const ImmutableString &rhs) {
return !(rhs == lhs);
}
inline bool operator!=(const ImmutableString &lhs, const char *rhs) {
return !(lhs == rhs);
}
inline bool operator!=(const char *lhs, const ImmutableString &rhs) {
return !(rhs == lhs);
}
inline std::ostream &operator<<(std::ostream &o, const ImmutableString &s) {
return o.write(s.c_str(), s.size());
}
inline std::string &operator+=(std::string &lhs, const ImmutableString &rhs) {
lhs.append(rhs.c_str(), rhs.size());
return lhs;
}
// StringRef is a reference to a string owned by something else. So
// it behaves like simple string, but it does not own pointer. When
// it is default constructed, it has empty string. You can freely
// copy or move around this struct, but never free its pointer. str()
// function can be used to export the content as std::string.
class StringRef {
public:
using traits_type = std::char_traits<char>;
using value_type = traits_type::char_type;
using allocator_type = std::allocator<char>;
using size_type = std::allocator_traits<allocator_type>::size_type;
using difference_type =
std::allocator_traits<allocator_type>::difference_type;
using const_reference = const value_type &;
using const_pointer = const value_type *;
using const_iterator = const_pointer;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
constexpr StringRef() : base(""), len(0) {}
explicit StringRef(const std::string &s) : base(s.c_str()), len(s.size()) {}
explicit StringRef(const ImmutableString &s)
: base(s.c_str()), len(s.size()) {}
explicit StringRef(const char *s) : base(s), len(strlen(s)) {}
constexpr StringRef(const char *s, size_t n) : base(s), len(n) {}
template <typename CharT>
constexpr StringRef(const CharT *s, size_t n)
: base(reinterpret_cast<const char *>(s)), len(n) {}
template <typename InputIt>
StringRef(InputIt first, InputIt last)
: base(reinterpret_cast<const char *>(&*first)),
len(std::distance(first, last)) {}
template <typename InputIt>
StringRef(InputIt *first, InputIt *last)
: base(reinterpret_cast<const char *>(first)),
len(std::distance(first, last)) {}
template <typename CharT, size_t N>
constexpr static StringRef from_lit(const CharT (&s)[N]) {
return StringRef{s, N - 1};
}
static StringRef from_maybe_nullptr(const char *s) {
if (s == nullptr) {
return StringRef();
}
return StringRef(s);
}
constexpr const_iterator begin() const { return base; };
constexpr const_iterator cbegin() const { return base; };
constexpr const_iterator end() const { return base + len; };
constexpr const_iterator cend() const { return base + len; };
const_reverse_iterator rbegin() const {
return const_reverse_iterator{base + len};
}
const_reverse_iterator crbegin() const {
return const_reverse_iterator{base + len};
}
const_reverse_iterator rend() const { return const_reverse_iterator{base}; }
const_reverse_iterator crend() const { return const_reverse_iterator{base}; }
constexpr const char *c_str() const { return base; }
constexpr size_type size() const { return len; }
constexpr bool empty() const { return len == 0; }
constexpr const_reference operator[](size_type pos) const {
return *(base + pos);
}
std::string str() const { return std::string(base, len); }
const uint8_t *byte() const {
return reinterpret_cast<const uint8_t *>(base);
}
private:
const char *base;
size_type len;
};
inline bool operator==(const StringRef &lhs, const StringRef &rhs) {
return lhs.size() == rhs.size() &&
std::equal(std::begin(lhs), std::end(lhs), std::begin(rhs));
}
inline bool operator==(const StringRef &lhs, const std::string &rhs) {
return lhs.size() == rhs.size() &&
std::equal(std::begin(lhs), std::end(lhs), std::begin(rhs));
}
inline bool operator==(const std::string &lhs, const StringRef &rhs) {
return rhs == lhs;
}
inline bool operator==(const StringRef &lhs, const char *rhs) {
return lhs.size() == strlen(rhs) &&
std::equal(std::begin(lhs), std::end(lhs), rhs);
}
inline bool operator==(const StringRef &lhs, const ImmutableString &rhs) {
return lhs.size() == rhs.size() &&
std::equal(std::begin(lhs), std::end(lhs), std::begin(rhs));
}
inline bool operator==(const ImmutableString &lhs, const StringRef &rhs) {
return rhs == lhs;
}
inline bool operator==(const char *lhs, const StringRef &rhs) {
return rhs == lhs;
}
inline bool operator!=(const StringRef &lhs, const StringRef &rhs) {
return !(lhs == rhs);
}
inline bool operator!=(const StringRef &lhs, const std::string &rhs) {
return !(lhs == rhs);
}
inline bool operator!=(const std::string &lhs, const StringRef &rhs) {
return !(rhs == lhs);
}
inline bool operator!=(const StringRef &lhs, const char *rhs) {
return !(lhs == rhs);
}
inline bool operator!=(const char *lhs, const StringRef &rhs) {
return !(rhs == lhs);
}
inline bool operator<(const StringRef &lhs, const StringRef &rhs) {
return std::lexicographical_compare(std::begin(lhs), std::end(lhs),
std::begin(rhs), std::end(rhs));
}
inline std::ostream &operator<<(std::ostream &o, const StringRef &s) {
return o.write(s.c_str(), s.size());
}
inline std::string &operator+=(std::string &lhs, const StringRef &rhs) {
lhs.append(rhs.c_str(), rhs.size());
return lhs;
}
inline int run_app(std::function<int(int, char **)> app, int argc,
char **argv) {
try {
return app(argc, argv);
} catch (const std::bad_alloc &) {
fputs("Out of memory\n", stderr);
} catch (const std::exception &x) {
fprintf(stderr, "Caught %s:\n%s\n", typeid(x).name(), x.what());
} catch (...) {
fputs("Unknown exception caught\n", stderr);
}
return EXIT_FAILURE;
}
} // namespace nghttp2
namespace std {
template <> struct hash<nghttp2::StringRef> {
std::size_t operator()(const nghttp2::StringRef &s) const noexcept {
// 32 bit FNV-1a:
// https://tools.ietf.org/html/draft-eastlake-fnv-16#section-6.1.1
uint32_t h = 2166136261u;
for (auto c : s) {
h ^= static_cast<uint8_t>(c);
h += (h << 1) + (h << 4) + (h << 7) + (h << 8) + (h << 24);
}
return h;
}
};
} // namespace std
#endif // TEMPLATE_H