[user/henk/code/inspircd.git] / include / hashcomp.h

/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
 * See: http://wiki.inspircd.org/Credits
 *
 * This program is free but copyrighted software; see
 *          the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#ifndef _HASHCOMP_H_
#define _HASHCOMP_H_

#include <cstring>
#include "hash_map.h"

/*******************************************************
 * This file contains classes and templates that deal
 * with the comparison and hashing of 'irc strings'.
 * An 'irc string' is a string which compares in a
 * case insensitive manner, and as per RFC 1459 will
 * treat [ identical to {, ] identical to }, and \
 * as identical to |.
 *
 * Our hashing functions are designed  to accept
 * std::string and compare/hash them as type irc::string
 * by converting them internally. This makes them
 * backwards compatible with other code which is not
 * aware of irc::string.
 *******************************************************/

#ifndef LOWERMAP
#define LOWERMAP

/** A mapping of uppercase to lowercase, including scandinavian
 * 'oddities' as specified by RFC1459, e.g. { -> [, and | -> \
 */
unsigned const char rfc_case_insensitive_map[256] = {
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,                                   /* 0-19 */
        20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,                         /* 20-39 */
        40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,                         /* 40-59 */
        60, 61, 62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,             /* 60-79 */
        112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 94, 95, 96, 97, 98, 99,           /* 80-99 */
        100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,     /* 100-119 */
        120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139,     /* 120-139 */
        140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,     /* 140-159 */
        160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179,     /* 160-179 */
        180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199,     /* 180-199 */
        200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,     /* 200-219 */
        220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,     /* 220-239 */
        240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255                          /* 240-255 */
};

/** Seperate from the other casemap tables so that code *can* still exclusively rely on RFC casemapping
 * if it must.
 *
 * This is provided as a pointer so that modules can change it to their custom mapping tables,
 * e.g. for national character support.
 */
CoreExport extern unsigned const char *national_case_insensitive_map;

/** Case insensitive map, ASCII rules.
 * That is;
 * [ != {, but A == a.
 */
unsigned const char ascii_case_insensitive_map[256] = {
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,                                   /* 0-19 */
        20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,                         /* 20-39 */
        40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,                         /* 40-59 */
        60, 61, 62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,             /* 60-79 */
        112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95, 96, 97, 98, 99,              /* 80-99 */
        100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,     /* 100-119 */
        120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139,     /* 120-139 */
        140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,     /* 140-159 */
        160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179,     /* 160-179 */
        180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199,     /* 180-199 */
        200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,     /* 200-219 */
        220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,     /* 220-239 */
        240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255                          /* 240-255 */
};

/** Case sensitive map.
 * Can technically also be used for ASCII case sensitive comparisons, as [ != {, etc.
 */
unsigned const char rfc_case_sensitive_map[256] = {
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
        21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
        41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
        61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80,
        81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100,
        101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120,
        121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140,
        141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160,
        161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180,
        181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200,
        201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220,
        221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240,
        241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};

#endif

template<typename T> const T& SearchAndReplace(T& text, const T& pattern, const T& replace)
{
        T replacement;
        if ((!pattern.empty()) && (!text.empty()))
        {
                for (std::string::size_type n = 0; n != text.length(); ++n)
                {
                        if (text.length() >= pattern.length() && text.substr(n, pattern.length()) == pattern)
                        {
                                /* Found the pattern in the text, replace it, and advance */
                                replacement.append(replace);
                                n = n + pattern.length() - 1;
                        }
                        else
                        {
                                replacement += text[n];
                        }
                }
        }
        text = replacement;
        return text;
}

/** The irc namespace contains a number of helper classes.
 */
namespace irc
{

        /** This class returns true if two strings match.
         * Case sensitivity is ignored, and the RFC 'character set'
         * is adhered to
         */
        struct StrHashComp
        {
                /** The operator () does the actual comparison in hash_map
                 */
                bool operator()(const std::string& s1, const std::string& s2) const;
        };

        /** The irc_char_traits class is used for RFC-style comparison of strings.
         * This class is used to implement irc::string, a case-insensitive, RFC-
         * comparing string class.
         */
        struct irc_char_traits : std::char_traits<char> {

                /** Check if two chars match.
                 * @param c1st First character
                 * @param c2nd Second character
                 * @return true if the characters are equal
                 */
                static bool eq(char c1st, char c2nd);

                /** Check if two chars do NOT match.
                 * @param c1st First character
                 * @param c2nd Second character
                 * @return true if the characters are unequal
                 */
                static bool ne(char c1st, char c2nd);

                /** Check if one char is less than another.
                 * @param c1st First character
                 * @param c2nd Second character
                 * @return true if c1st is less than c2nd
                 */
                static bool lt(char c1st, char c2nd);

                /** Compare two strings of size n.
                 * @param str1 First string
                 * @param str2 Second string
                 * @param n Length to compare to
                 * @return similar to strcmp, zero for equal, less than zero for str1
                 * being less and greater than zero for str1 being greater than str2.
                 */
                static CoreExport int compare(const char* str1, const char* str2, size_t n);

                /** Find a char within a string up to position n.
                 * @param s1 String to find in
                 * @param n Position to search up to
                 * @param c Character to search for
                 * @return Pointer to the first occurance of c in s1
                 */
                static CoreExport const char* find(const char* s1, int  n, char c);
        };

        /** Compose a hex string from raw data.
         * @param raw The raw data to compose hex from
         * @pram rawsz The size of the raw data buffer
         * @return The hex string.
         */
        CoreExport std::string hex(const unsigned char *raw, size_t rawsz);

        /** This typedef declares irc::string based upon irc_char_traits.
         */
        typedef std::basic_string<char, irc_char_traits, std::allocator<char> > string;

        /** irc::stringjoiner joins string lists into a string, using
         * the given seperator string.
         * This class can join a vector of std::string, a deque of
         * std::string, or a const char* const* array, using overloaded
         * constructors.
         */
        class CoreExport stringjoiner : public classbase
        {
         private:

                /** Output string
                 */
                std::string joined;

         public:

                /** Join elements of a vector, between (and including) begin and end
                 * @param seperator The string to seperate values with
                 * @param sequence One or more items to seperate
                 * @param begin The starting element in the sequence to be joined
                 * @param end The ending element in the sequence to be joined
                 */
                stringjoiner(const std::string &seperator, const std::vector<std::string> &sequence, int begin, int end);

                /** Join elements of a deque, between (and including) begin and end
                 * @param seperator The string to seperate values with
                 * @param sequence One or more items to seperate
                 * @param begin The starting element in the sequence to be joined
                 * @param end The ending element in the sequence to be joined
                 */
                stringjoiner(const std::string &seperator, const std::deque<std::string> &sequence, int begin, int end);

                /** Join elements of an array of char arrays, between (and including) begin and end
                 * @param seperator The string to seperate values with
                 * @param sequence One or more items to seperate
                 * @param begin The starting element in the sequence to be joined
                 * @param end The ending element in the sequence to be joined
                 */
                stringjoiner(const std::string &seperator, const char* const* sequence, int begin, int end);

                /** Get the joined sequence
                 * @return A reference to the joined string
                 */
                std::string& GetJoined();
        };

        /** irc::modestacker stacks mode sequences into a list.
         * It can then reproduce this list, clamped to a maximum of MAXMODES
         * values per line.
         */
        class CoreExport modestacker : public classbase
        {
         private:
                InspIRCd* ServerInstance;

                /** The mode sequence and its parameters
                 */
                std::deque<std::string> sequence;

                /** True if the mode sequence is initially adding
                 * characters, false if it is initially removing
                 * them
                 */
                bool adding;
         public:

                /** Construct a new modestacker.
                 * @param add True if the stack is adding modes,
                 * false if it is removing them
                 */
                modestacker(InspIRCd* Instance, bool add);

                /** Push a modeletter and its parameter onto the stack.
                 * No checking is performed as to if this mode actually
                 * requires a parameter. If you stack invalid mode
                 * sequences, they will be tidied if and when they are
                 * passed to a mode parser.
                 * @param modeletter The mode letter to insert
                 * @param parameter The parameter for the mode
                 */
                void Push(char modeletter, const std::string &parameter);

                /** Push a modeletter without parameter onto the stack.
                 * No checking is performed as to if this mode actually
                 * requires a parameter. If you stack invalid mode
                 * sequences, they will be tidied if and when they are
                 * passed to a mode parser.
                 * @param modeletter The mode letter to insert
                 */
                void Push(char modeletter);

                /** Push a '+' symbol onto the stack.
                 */
                void PushPlus();

                /** Push a '-' symbol onto the stack.
                 */
                void PushMinus();

                /** Return zero or more elements which form the
                 * mode line. This will be clamped to a max of
                 * MAXMODES items (MAXMODES-1 mode parameters and
                 * one mode sequence string), and max_line_size
                 * characters. As specified below, this function
                 * should be called in a loop until it returns zero,
                 * indicating there are no more modes to return.
                 * @param result The deque to populate. This will
                 * be cleared before it is used.
                 * @param max_line_size The maximum size of the line
                 * to build, in characters, seperate to MAXMODES.
                 * @return The number of elements in the deque.
                 * The function should be called repeatedly until it
                 * returns 0, in case there are multiple lines of
                 * mode changes to be obtained.
                 */
                int GetStackedLine(std::deque<std::string> &result, int max_line_size = 360);
        };

        /** irc::tokenstream reads a string formatted as per RFC1459 and RFC2812.
         * It will split the string into 'tokens' each containing one parameter
         * from the string.
         * For instance, if it is instantiated with the string:
         * "PRIVMSG #test :foo bar baz qux"
         * then each successive call to tokenstream::GetToken() will return
         * "PRIVMSG", "#test", "foo bar baz qux", "".
         * Note that if the whole string starts with a colon this is not taken
         * to mean the string is all one parameter, and the first item in the
         * list will be ":item". This is to allow for parsing 'source' fields
         * from data.
         */
        class CoreExport tokenstream : public classbase
        {
         private:

                /** Original string
                 */
                std::string tokens;

                /** Last position of a seperator token
                 */
                std::string::iterator last_starting_position;

                /** Current string position
                 */
                std::string::iterator n;

                /** True if the last value was an ending value
                 */
                bool last_pushed;
         public:

                /** Create a tokenstream and fill it with the provided data
                 */
                tokenstream(const std::string &source);

                /** Destructor
                 */
                ~tokenstream();

                /** Fetch the next token from the stream as a std::string
                 * @param token The next token available, or an empty string if none remain
                 * @return True if tokens are left to be read, false if the last token was just retrieved.
                 */
                bool GetToken(std::string &token);

                /** Fetch the next token from the stream as an irc::string
                 * @param token The next token available, or an empty string if none remain
                 * @return True if tokens are left to be read, false if the last token was just retrieved.
                 */
                bool GetToken(irc::string &token);

                /** Fetch the next token from the stream as an integer
                 * @param token The next token available, or undefined if none remain
                 * @return True if tokens are left to be read, false if the last token was just retrieved.
                 */
                bool GetToken(int &token);

                /** Fetch the next token from the stream as a long integer
                 * @param token The next token available, or undefined if none remain
                 * @return True if tokens are left to be read, false if the last token was just retrieved.
                 */
                bool GetToken(long &token);
        };

        /** irc::sepstream allows for splitting token seperated lists.
         * Each successive call to sepstream::GetToken() returns
         * the next token, until none remain, at which point the method returns
         * an empty string.
         */
        class CoreExport sepstream : public classbase
        {
         private:
                /** Original string.
                 */
                std::string tokens;
                /** Last position of a seperator token
                 */
                std::string::iterator last_starting_position;
                /** Current string position
                 */
                std::string::iterator n;
                /** Seperator value
                 */
                char sep;
         public:
                /** Create a sepstream and fill it with the provided data
                 */
                sepstream(const std::string &source, char seperator);

                /** Destructor
                 */
                virtual ~sepstream();

                /** Fetch the next token from the stream
                 * @param token The next token from the stream is placed here
                 * @return True if tokens still remain, false if there are none left
                 */
                virtual bool GetToken(std::string &token);

                /** Fetch the entire remaining stream, without tokenizing
                 * @return The remaining part of the stream
                 */
                virtual const std::string GetRemaining();

                /** Returns true if the end of the stream has been reached
                 * @return True if the end of the stream has been reached, otherwise false
                 */
                virtual bool StreamEnd();
        };

        /** A derived form of sepstream, which seperates on commas
         */
        class CoreExport commasepstream : public sepstream
        {
         public:
                /** Initialize with comma seperator
                 */
                commasepstream(const std::string &source) : sepstream(source, ',')
                {
                }
        };

        /** A derived form of sepstream, which seperates on spaces
         */
        class CoreExport spacesepstream : public sepstream
        {
         public:
                /** Initialize with space seperator
                 */
                spacesepstream(const std::string &source) : sepstream(source, ' ')
                {
                }
        };

        /** The portparser class seperates out a port range into integers.
         * A port range may be specified in the input string in the form
         * "6660,6661,6662-6669,7020". The end of the stream is indicated by
         * a return value of 0 from portparser::GetToken(). If you attempt
         * to specify an illegal range (e.g. one where start >= end, or
         * start or end < 0) then GetToken() will return the first element
         * of the pair of numbers.
         */
        class CoreExport portparser : public classbase
        {
         private:

                /** Used to split on commas
                 */
                commasepstream* sep;

                /** Current position in a range of ports
                 */
                long in_range;

                /** Starting port in a range of ports
                 */
                long range_begin;

                /** Ending port in a range of ports
                 */
                long range_end;

                /** Allow overlapped port ranges
                 */
                bool overlapped;

                /** Used to determine overlapping of ports
                 * without O(n) algorithm being used
                 */
                std::map<long, bool> overlap_set;

                /** Returns true if val overlaps an existing range
                 */
                bool Overlaps(long val);
         public:

                /** Create a portparser and fill it with the provided data
                 * @param source The source text to parse from
                 * @param allow_overlapped Allow overlapped ranges
                 */
                portparser(const std::string &source, bool allow_overlapped = true);

                /** Frees the internal commasepstream object
                 */
                ~portparser();

                /** Fetch the next token from the stream
                 * @return The next port number is returned, or 0 if none remain
                 */
                long GetToken();
        };

        /** Turn _ characters in a string into spaces
         * @param n String to translate
         * @return The new value with _ translated to space.
         */
        CoreExport const char* Spacify(const char* n);
}

/* Define operators for using >> and << with irc::string to an ostream on an istream. */
/* This was endless fun. No. Really. */
/* It was also the first core change Ommeh made, if anyone cares */

/** Operator << for irc::string
 */
inline std::ostream& operator<<(std::ostream &os, const irc::string &str) { return os << str.c_str(); }

/** Operator >> for irc::string
 */
inline std::istream& operator>>(std::istream &is, irc::string &str)
{
        std::string tmp;
        is >> tmp;
        str = tmp.c_str();
        return is;
}

/* Define operators for + and == with irc::string to std::string for easy assignment
 * and comparison
 *
 * Operator +
 */
inline std::string operator+ (std::string& leftval, irc::string& rightval)
{
        return leftval + std::string(rightval.c_str());
}

/* Define operators for + and == with irc::string to std::string for easy assignment
 * and comparison
 *
 * Operator +
 */
inline irc::string operator+ (irc::string& leftval, std::string& rightval)
{
        return leftval + irc::string(rightval.c_str());
}

/* Define operators for + and == with irc::string to std::string for easy assignment
 * and comparison
 *
 * Operator ==
 */
inline bool operator== (const std::string& leftval, const irc::string& rightval)
{
        return (leftval.c_str() == rightval);
}

/* Define operators for + and == with irc::string to std::string for easy assignment
 * and comparison
 *
 * Operator ==
 */
inline bool operator== (const irc::string& leftval, const std::string& rightval)
{
        return (leftval == rightval.c_str());
}

/* Define operators != for irc::string to std::string for easy comparison
 */
inline bool operator!= (const irc::string& leftval, const std::string& rightval)
{
        return !(leftval == rightval.c_str());
}

/* Define operators != for std::string to irc::string for easy comparison
 */
inline bool operator!= (const std::string& leftval, const irc::string& rightval)
{
        return !(leftval.c_str() == rightval);
}

// FIXME MAXBUF messes up these
#if 0
template<std::size_t N>
static inline bool operator == (std::string const &lhs, char const (&rhs)[N])
{
        return lhs.length() == N - 1 && !std::memcmp(lhs.data(), rhs, N - 1);
}

template<std::size_t N>
static inline bool operator != (std::string const &lhs, char const (&rhs)[N])
{
        return !(lhs == rhs);
}
#endif

/** Assign an irc::string to a std::string.
 */
inline std::string assign(const irc::string &other) { return other.c_str(); }

/** Assign a std::string to an irc::string.
 */
inline irc::string assign(const std::string &other) { return other.c_str(); }

/** Trim the leading and trailing spaces from a std::string.
 */
inline std::string& trim(std::string &str)
{
        std::string::size_type start = str.find_first_not_of(" ");
        std::string::size_type end = str.find_last_not_of(" ");
        if (start == std::string::npos || end == std::string::npos)
                str = "";
        else
                str = str.substr(start, end-start+1);

        return str;
}

/** Hashing stuff is totally different on vc++'s hash_map implementation, so to save a buttload of
 * #ifdefs we'll just do it all at once. Except, of course, with TR1, when it's the same as GCC.
 */
BEGIN_HASHMAP_NAMESPACE

        /** Hashing function to hash irc::string
         */
#if defined(WINDOWS) && !defined(HAS_TR1_UNORDERED)
        template<> class CoreExport hash_compare<irc::string, std::less<irc::string> >
        {
        public:
                enum { bucket_size = 4, min_buckets = 8 }; /* Got these numbers from the CRT source, if anyone wants to change them feel free. */

                /** Compare two irc::string values for hashing in hash_map
                 */
                bool operator()(const irc::string & s1, const irc::string & s2) const
                {
                        if(s1.length() != s2.length()) return true;
                        return (irc::irc_char_traits::compare(s1.c_str(), s2.c_str(), (size_t)s1.length()) < 0);
                }

                /** Hash an irc::string value for hash_map
                 */
                size_t operator()(const irc::string & s) const;
        };

        template<> class CoreExport hash_compare<std::string, std::less<std::string> >
        {
        public:
                enum { bucket_size = 4, min_buckets = 8 }; /* Again, from the CRT source */

                /** Compare two std::string values for hashing in hash_map
                 */
                bool operator()(const std::string & s1, const std::string & s2) const
                {
                        if(s1.length() != s2.length()) return true;
                        return (irc::irc_char_traits::compare(s1.c_str(), s2.c_str(), (size_t)s1.length()) < 0);
                }

                /** Hash a std::string using RFC1459 case sensitivity rules
                * @param s A string to hash
                * @return The hash value
                */
                size_t operator()(const std::string & s) const;
        };
#else

        template<> struct hash<irc::string>
        {
                /** Hash an irc::string using RFC1459 case sensitivity rules
                 * @param s A string to hash
                 * @return The hash value
                 */
                size_t CoreExport operator()(const irc::string &s) const;
        };

        /* XXX FIXME: Implement a hash function overriding std::string's that works with TR1! */

#ifdef HASHMAP_DEPRECATED
        struct insensitive
#else
        CoreExport template<> struct hash<std::string>
#endif
        {
                size_t CoreExport operator()(const std::string &s) const;
        };

#endif

        /** Convert a string to lower case respecting RFC1459
        * @param n A string to lowercase
        */
        void strlower(char *n);

END_HASHMAP_NAMESPACE

#endif