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easy_profiler/easy_profiler_core/hashed_cstr.h

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/************************************************************************
* file name : hashed_str.h
* ----------------- :
* creation time : 2016/09/11
* author : Victor Zarubkin
* email : v.s.zarubkin@gmail.com
* ----------------- :
* description : The file contains definition of C-strings with calculated hash-code.
* : These strings may be used as optimized keys for std::unordered_map.
* ----------------- :
* change log : * 2016/09/11 Victor Zarubkin: Initial commit. Moved sources from reader.cpp
* :
* : *
* ----------------- :
* license : Lightweight profiler library for c++
* : Copyright(C) 2016-2017 Sergey Yagovtsev, Victor Zarubkin
* :
* : Licensed under either of
* : * MIT license (LICENSE.MIT or http://opensource.org/licenses/MIT)
* : * Apache License, Version 2.0, (LICENSE.APACHE or http://www.apache.org/licenses/LICENSE-2.0)
* : at your option.
* :
* : The MIT License
* :
* : 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.
* :
* : The Apache License, Version 2.0 (the "License")
* :
* : You may not use this file except in compliance with the License.
* : You may obtain a copy of the License at
* :
* : http://www.apache.org/licenses/LICENSE-2.0
* :
* : Unless required by applicable law or agreed to in writing, software
* : distributed under the License is distributed on an "AS IS" BASIS,
* : WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* : See the License for the specific language governing permissions and
* : limitations under the License.
************************************************************************/
#ifndef EASY_PROFILER__HASHED_CSTR__H_
#define EASY_PROFILER__HASHED_CSTR__H_
#include <functional>
#include <string.h>
#include <string>
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
#if 0 == 1//defined(_MSC_VER)// && _MSC_VER >= 1800
# define EASY_PROFILER_HASHED_CSTR_DEFINED
namespace profiler {
/** \brief Simple C-string pointer with length.
It is used as base class for a key in std::unordered_map.
It is used to get better performance than std::string.
It simply stores a pointer and a length, there is no
any memory allocation and copy.
\warning Make sure you know what you are doing. You have to be sure that
pointed C-string will exist until you finish using this cstring.
\ingroup profiler
*/
class cstring
{
protected:
const char* m_str;
size_t m_len;
public:
cstring(const char* _str) : m_str(_str), m_len(strlen(_str))
{
}
cstring(const char* _str, size_t _len) : m_str(_str), m_len(_len)
{
}
cstring(const cstring&) = default;
cstring& operator = (const cstring&) = default;
inline bool operator == (const cstring& _other) const
{
return m_len == _other.m_len && !strncmp(m_str, _other.m_str, m_len);
}
inline bool operator != (const cstring& _other) const
{
return !operator == (_other);
}
inline bool operator < (const cstring& _other) const
{
if (m_len == _other.m_len)
{
return strncmp(m_str, _other.m_str, m_len) < 0;
}
return m_len < _other.m_len;
}
inline const char* c_str() const
{
return m_str;
}
inline size_t size() const
{
return m_len;
}
}; // END of class cstring.
/** \brief cstring with precalculated hash.
This is used to calculate hash for C-string and to cache it
to be used in the future without recurring hash calculatoin.
\note This class is used as a key in std::unordered_map.
\ingroup profiler
*/
class hashed_cstr : public cstring
{
typedef cstring Parent;
size_t m_hash;
public:
hashed_cstr(const char* _str) : Parent(_str), m_hash(0)
{
m_hash = ::std::_Hash_seq((const unsigned char *)m_str, m_len);
}
hashed_cstr(const char* _str, size_t _hash_code) : Parent(_str), m_hash(_hash_code)
{
}
hashed_cstr(const char* _str, size_t _len, size_t _hash_code) : Parent(_str, _len), m_hash(_hash_code)
{
}
hashed_cstr(const hashed_cstr&) = default;
hashed_cstr& operator = (const hashed_cstr&) = default;
inline bool operator == (const hashed_cstr& _other) const
{
return m_hash == _other.m_hash && Parent::operator == (_other);
}
inline bool operator != (const hashed_cstr& _other) const
{
return !operator == (_other);
}
inline size_t hcode() const
{
return m_hash;
}
}; // END of class hashed_cstr.
} // END of namespace profiler.
namespace std {
/** \brief Simply returns precalculated hash of a C-string. */
template <> struct hash<::profiler::hashed_cstr> {
typedef ::profiler::hashed_cstr argument_type;
typedef size_t result_type;
inline size_t operator () (const ::profiler::hashed_cstr& _str) const {
return _str.hcode();
}
};
} // END of namespace std.
#else ////////////////////////////////////////////////////////////////////
// TODO: Create hashed_cstr for Linux (need to use Linux version of std::_Hash_seq)
#endif
namespace profiler {
class hashed_stdstring
{
::std::string m_str;
size_t m_hash;
public:
hashed_stdstring(const char* _str) : m_str(_str), m_hash(::std::hash<::std::string>()(m_str))
{
}
hashed_stdstring(const ::std::string& _str) : m_str(_str), m_hash(::std::hash<::std::string>()(m_str))
{
}
hashed_stdstring(::std::string&& _str) : m_str(::std::forward<::std::string&&>(_str)), m_hash(::std::hash<::std::string>()(m_str))
{
}
hashed_stdstring(hashed_stdstring&& _other) : m_str(::std::move(_other.m_str)), m_hash(_other.m_hash)
{
}
hashed_stdstring(const char* _str, size_t _hash_code) : m_str(_str), m_hash(_hash_code)
{
}
hashed_stdstring(const ::std::string& _str, size_t _hash_code) : m_str(_str), m_hash(_hash_code)
{
}
hashed_stdstring(::std::string&& _str, size_t _hash_code) : m_str(::std::forward<::std::string&&>(_str)), m_hash(_hash_code)
{
}
hashed_stdstring(const hashed_stdstring&) = default;
hashed_stdstring& operator = (const hashed_stdstring&) = default;
hashed_stdstring& operator = (hashed_stdstring&& _other)
{
m_str = ::std::move(_other.m_str);
m_hash = _other.m_hash;
return *this;
}
inline bool operator == (const hashed_stdstring& _other) const
{
return m_hash == _other.m_hash && m_str == _other.m_str;
}
inline bool operator != (const hashed_stdstring& _other) const
{
return !operator == (_other);
}
inline size_t hcode() const
{
return m_hash;
}
inline const char* c_str() const
{
return m_str.c_str();
}
inline size_t size() const
{
return m_str.size();
}
}; // END of class hashed_stdstring.
} // END of namespace profiler.
namespace std {
/** \brief Simply returns precalculated hash of a std::string. */
template <> struct hash<::profiler::hashed_stdstring> {
typedef ::profiler::hashed_stdstring argument_type;
typedef size_t result_type;
inline size_t operator () (const ::profiler::hashed_stdstring& _str) const {
return _str.hcode();
}
};
} // END of namespace std.
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
#endif // EASY_PROFILER__HASHED_CSTR__H_
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