///////////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2008-2012 Artyom Beilis (Tonkikh) <artyomtnk@yahoo.com>
//
// See accompanying file COPYING.TXT file for licensing details.
//
///////////////////////////////////////////////////////////////////////////////
#ifndef CPPCMS_STRING_KEY_H
#define CPPCMS_STRING_KEY_H
#include <string>
#include <string.h>
#include <algorithm>
#include <stdexcept>
#include <ostream>
namespace cppcms {
///
/// \brief This is a special object that may hold an std::string or
/// alternatively reference to external (unowned) chunk of text
///
/// It is designed to be used for efficiency and reduce amount of
/// memory allocations and copies.
///
/// It has interface that is roughly similar to the interface of std::string,
/// but it does not provide a members that can mutate it or provide a NUL terminated
/// string c_str().
///
class string_key {
public:
///
/// Iterator type
///
typedef char const *const_iterator;
///
/// The last position of the character in the string
///
static const size_t npos = -1;
///
/// Default constructor - empty key
///
string_key() :
begin_(0),
end_(0)
{
}
///
/// Create a new string copying the \a key
///
string_key(char const *key) :
begin_(0),
end_(0),
key_(key)
{
}
///
/// Create a new string copying the \a key
///
string_key(std::string const &key) :
begin_(0),
end_(0),
key_(key)
{
}
///
/// String size in bytes
///
size_t size() const
{
return end() - begin();
}
///
/// Same as size()
///
size_t length() const
{
return size();
}
///
/// Clear the string
///
void clear()
{
begin_ = end_ = 0;
key_.clear();
}
///
/// Check if the string is empty
///
bool empty() const
{
return end() == begin();
}
///
/// Find first occurrence of a character \c in the string starting from
/// position \a pos. Returns npos if not character found.
///
size_t find(char c,size_t pos = 0) const
{
size_t s = size();
if(pos >= s)
return npos;
char const *p=begin() + pos;
while(pos <= s && *p!=c) {
pos++;
p++;
}
if(pos >= s)
return npos;
return pos;
}
///
/// Create a substring from this string starting from character \a pos of size at most \a n
///
string_key substr(size_t pos = 0,size_t n=npos) const
{
string_key tmp = unowned_substr(pos,n);
return string_key(std::string(tmp.begin(),tmp.end()));
}
///
/// Create a substring from this string starting from character \a pos of size at most \a n
/// such that the memory is not copied but only reference by the created substring
///
string_key unowned_substr(size_t pos = 0,size_t n=npos) const
{
if(pos >= size()) {
return string_key();
}
char const *p=begin() + pos;
char const *e=end();
if(n > size_t(e-p)) {
return string_key(p,e);
}
else {
return string_key(p,p+n);
}
}
///
/// Get a character at position \a n
///
char const &operator[](size_t n) const
{
return *(begin() + n);
}
///
/// Get a character at position \a n, if \a n is not valid position, throws std::out_of_range exception
///
char const &at(size_t n) const
{
if(n > size())
throw std::out_of_range("cppcms::string_key::at() range error");
return *(begin() + n);
}
///
/// Create a string from \a v without copying the memory. \a v should remain valid
/// as long as this object is used
///
static string_key unowned(std::string const &v)
{
return string_key(v.c_str(),v.c_str()+v.size());
}
///
/// Create a string from \a str without copying the memory. \a str should remain valid
/// as long as this object is used
///
static string_key unowned(char const *str)
{
char const *end = str;
while(*end)
end++;
return string_key(str,end);
}
///
/// Create a string from \a characters at rang [begin,end) without copying the memory.
/// The range should remain valid as long as this object is used
///
static string_key unowned(char const *begin,char const *end)
{
return string_key(begin,end);
}
///
/// Get a pointer to the first character in the string
///
char const *begin() const
{
if(begin_)
return begin_;
return key_.c_str();
}
///
/// Get a pointer to the one past last character in the string
///
char const *end() const
{
if(begin_)
return end_;
return key_.c_str() + key_.size();
}
///
/// Compare two strings
///
bool operator<(string_key const &other) const
{
return std::lexicographical_compare( begin(),end(),
other.begin(),other.end(),
std::char_traits<char>::lt);
}
///
/// Compare two strings
///
bool operator>(string_key const &other) const
{
return other < *this;
}
///
/// Compare two strings
///
bool operator>=(string_key const &other) const
{
return !(*this < other);
}
///
/// Compare two strings
///
bool operator<=(string_key const &other) const
{
return !(*this > other);
}
///
/// Compare two strings
///
bool operator==(string_key const &other) const
{
return (end() - begin() == other.end() - other.begin())
&& memcmp(begin(),other.begin(),end()-begin()) == 0;
}
///
/// Compare two strings
///
bool operator!=(string_key const &other) const
{
return !(*this==other);
}
///
/// Get the pointer to the first character in the string. Note it should not be NUL terminated
///
char const *data() const
{
return begin();
}
///
/// Create std::string from the key
///
std::string str() const
{
if(begin_)
return std::string(begin_,end_-begin_);
else
return key_;
}
///
/// Convert the key to the std::string
///
operator std::string() const
{
return str();
}
private:
string_key(char const *b,char const *e) :
begin_(b),
end_(e)
{
}
char const *begin_;
char const *end_;
std::string key_;
};
///
/// Write the string to the stream
///
inline std::ostream &operator<<(std::ostream &out,string_key const &s)
{
out.write(s.data(),s.size());
return out;
}
///
/// Compare two strings
///
inline bool operator==(string_key const &l,char const *r)
{
return l==string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator==(char const *l,string_key const &r)
{
return string_key::unowned(l) == r;
}
///
/// Compare two strings
///
inline bool operator==(string_key const &l,std::string const &r)
{
return l==string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator==(std::string const &l,string_key const &r)
{
return string_key::unowned(l) == r;
}
///
/// Compare two strings
///
inline bool operator!=(string_key const &l,char const *r)
{
return l!=string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator!=(char const *l,string_key const &r)
{
return string_key::unowned(l) != r;
}
///
/// Compare two strings
///
inline bool operator!=(string_key const &l,std::string const &r)
{
return l!=string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator!=(std::string const &l,string_key const &r)
{
return string_key::unowned(l) != r;
}
///
/// Compare two strings
///
inline bool operator<=(string_key const &l,char const *r)
{
return l<=string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator<=(char const *l,string_key const &r)
{
return string_key::unowned(l) <= r;
}
///
/// Compare two strings
///
inline bool operator<=(string_key const &l,std::string const &r)
{
return l<=string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator<=(std::string const &l,string_key const &r)
{
return string_key::unowned(l) <= r;
}
///
/// Compare two strings
///
inline bool operator>=(string_key const &l,char const *r)
{
return l>=string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator>=(char const *l,string_key const &r)
{
return string_key::unowned(l) >= r;
}
///
/// Compare two strings
///
inline bool operator>=(string_key const &l,std::string const &r)
{
return l>=string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator>=(std::string const &l,string_key const &r)
{
return string_key::unowned(l) >= r;
}
///
/// Compare two strings
///
inline bool operator<(string_key const &l,char const *r)
{
return l<string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator<(char const *l,string_key const &r)
{
return string_key::unowned(l) < r;
}
///
/// Compare two strings
///
inline bool operator<(string_key const &l,std::string const &r)
{
return l<string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator<(std::string const &l,string_key const &r)
{
return string_key::unowned(l) < r;
}
///
/// Compare two strings
///
inline bool operator>(string_key const &l,char const *r)
{
return l>string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator>(char const *l,string_key const &r)
{
return string_key::unowned(l) > r;
}
///
/// Compare two strings
///
inline bool operator>(string_key const &l,std::string const &r)
{
return l>string_key::unowned(r);
}
///
/// Compare two strings
///
inline bool operator>(std::string const &l,string_key const &r)
{
return string_key::unowned(l) > r;
}
}
#endif
