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

/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
 * See: http://www.inspircd.org/wiki/index.php/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#ifndef _HASHCOMP_H_
#define _HASHCOMP_H_

#include "inspircd_config.h"
#include "socket.h"
#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.
 *******************************************************/
 
using namespace std;
using irc::sockets::insp_aton;
using irc::sockets::insp_ntoa;
using irc::sockets::insp_inaddr;

#ifndef LOWERMAP
#define LOWERMAP
/** A mapping of uppercase to lowercase, including scandinavian
 * 'oddities' as specified by RFC1459, e.g. { -> [, and | -> \
 */
unsigned const char lowermap[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 */
};
#endif

/** Because of weirdness in g++, before 3.x this was namespace std. It's now __gnu_cxx.
 * This is a #define'd alias.
 */
namespace nspace
{
        /** Convert a string to lower case respecting RFC1459
         * @param n A string to lowercase
         */
        void strlower(char *n);

        /** Hashing function to hash insp_inaddr structs
         */
        template<> struct hash<insp_inaddr>
        {
                /** Hash an insp_inaddr
                 * @param a An insp_inaddr to hash
                 * @return The hash value
                 */
                size_t operator()(const insp_inaddr &a) const;
        };

        /** Hashing function to hash std::string without respect to case
         */
        template<> struct hash<std::string>
        {
                /** Hash a std::string using RFC1459 case sensitivity rules
                 * @param s A string to hash
                 * @return The hash value
                 */
                size_t operator()(const string &s) const;
        };
}

/** 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;
        };


        /** This class returns true if two insp_inaddr structs match.
         * Checking is done by copying both into a size_t then doing a
         * numeric comparison of the two.
         */
        struct InAddr_HashComp
        {
                /** The operator () does the actual comparison in hash_map
                 */
                bool operator()(const insp_inaddr &s1, const insp_inaddr &s2) const;
        };

        /** 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** array, using overloaded
         * constructors.
         */
        class stringjoiner
        {
         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** 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 modestacker
        {
         private:
                /** 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(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+1 items (MAXMODES mode parameters and
                 * one mode sequence string).
                 * @param result The deque to populate. This will
                 * be cleared before it is used.
                 * @return The number of elements in the deque
                 */
                int GetStackedLine(std::deque<std::string> &result);
        };

        /** 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 tokenstream
        {
         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);
                ~tokenstream();

                /** Fetch the next token from the stream
                 * @return The next token is returned, or an empty string if none remain
                 */
                const std::string GetToken();
        };

        /** 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 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);
                virtual ~sepstream();

                /** Fetch the next token from the stream
                 * @return The next token is returned, or an empty string if none remain
                 */
                virtual const std::string GetToken();
        };

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

        /** A derived form of sepstream, which seperates on spaces
         */
        class spacesepstream : public sepstream
        {
         public:
                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 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();
        };

        /** Used to hold a bitfield definition in dynamicbitmask.
         * You must be allocated one of these by dynamicbitmask::Allocate(),
         * you should not fill the values yourself!
         */
        typedef std::pair<size_t, unsigned char> bitfield;

        /** The irc::dynamicbitmask class is used to maintain a bitmap of
         * boolean values, which can grow to any reasonable size no matter
         * how many bitfields are in it.
         *
         * It starts off at 32 bits in size, large enough to hold 32 boolean
         * values, with a memory allocation of 8 bytes. If you allocate more
         * than 32 bits, the class will grow the bitmap by 8 bytes at a time
         * for each set of 8 bitfields you allocate with the Allocate()
         * method.
         *
         * This method is designed so that multiple modules can be allocated
         * bit values in a bitmap dynamically, rather than having to define
         * costs in a fixed size unsigned integer and having the possibility
         * of collisions of values in different third party modules.
         *
         * IMPORTANT NOTE:
         *
         * To use this class, you must derive from it.
         * This is because each derived instance has its own freebits array
         * which can determine what bitfields are allocated on a TYPE BY TYPE
         * basis, e.g. an irc::dynamicbitmask type for userrecs, and one for
         * chanrecs, etc. You should inheret it in a very simple way as follows.
         * The base class will resize and maintain freebits as required, you are
         * just required to make the pointer static and specific to this class
         * type.
         *
         * \code
         * class mydbitmask : public irc::dynamicbitmask
         * {
         *  private:
         *
         *      static unsigned char* freebits;
         *
         *  public:
         *
         *      mydbitmask() : irc::dynamicbitmask()
         *      {
         *          freebits = new unsigned char[this->bits_size];
         *          memset(freebits, 0, this->bits_size);
         *      }
         *
         *      ~mydbitmask()
         *      {
         *          delete[] freebits;
         *      }
         *
         *      unsigned char* GetFreeBits()
         *      {
         *          return freebits;
         *      }
         *
         *      void SetFreeBits(unsigned char* freebt)
         *      {
         *          freebits = freebt;
         *      }
         * };
         * \endcode
         */
        class dynamicbitmask : public classbase
        {
         private:
                /** Data bits. We start with four of these,
                 * and we grow the bitfield as we allocate
                 * more than 32 entries with Allocate().
                 */
                unsigned char* bits;
         protected:
                /** Current set size (size of freebits and bits).
                 * Both freebits and bits will ALWAYS be the
                 * same length.
                 */
                unsigned char bits_size;
         public:
                /** Allocate the initial memory for bits and
                 * freebits and zero the memory.
                 */
                dynamicbitmask();

                /** Free the memory used by bits and freebits
                 */
                virtual ~dynamicbitmask();

                /** Allocate an irc::bitfield.
                 * @return An irc::bitfield which can be used
                 * with Get, Deallocate and Toggle methods.
                 * @throw Can throw std::bad_alloc if there is
                 * no ram left to grow the bitmask.
                 */
                bitfield Allocate();

                /** Deallocate an irc::bitfield.
                 * @param An irc::bitfield to deallocate.
                 * @return True if the bitfield could be
                 * deallocated, false if it could not.
                 */
                bool Deallocate(bitfield &pos);

                /** Toggle the value of a bitfield.
                 * @param pos A bitfield to allocate, previously
                 * allocated by dyamicbitmask::Allocate().
                 * @param state The state to set the field to.
                 */
                void Toggle(bitfield &pos, bool state);

                /** Get the value of a bitfield.
                 * @param pos A bitfield to retrieve, previously
                 * allocated by dyamicbitmask::Allocate().
                 * @return The value of the bitfield.
                 * @throw Will throw ModuleException if the bitfield
                 * you provide is outside of the range
                 * 0 >= bitfield.first < size_bits.
                 */
                bool Get(bitfield &pos);

                /** Return the size in bytes allocated to the bits
                 * array.
                 * Note that the actual allocation is twice this,
                 * as there are an equal number of bytes allocated
                 * for the freebits array.
                 */
                unsigned char GetSize();

                virtual unsigned char* GetFreeBits() { return NULL; }

                virtual void SetFreeBits(unsigned char* freebits) { }
        };

        /** 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
                 */
                static bool eq(char c1st, char c2nd);

                /** Check if two chars do NOT match
                 */
                static bool ne(char c1st, char c2nd);

                /** Check if one char is less than another
                 */
                static bool lt(char c1st, char c2nd);

                /** Compare two strings of size n
                 */
                static int compare(const char* str1, const char* str2, size_t n);

                /** Find a char within a string up to position n
                 */
                static const char* find(const char* s1, int  n, char c);
        };

        std::string hex(const unsigned char *raw, size_t rawsz);

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

        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 */
std::ostream& operator<<(std::ostream &os, const irc::string &str);
std::istream& operator>>(std::istream &is, irc::string &str);

/* Define operators for + and == with irc::string to std::string for easy assignment
 * and comparison - Brain
 */
std::string operator+ (std::string& leftval, irc::string& rightval);
irc::string operator+ (irc::string& leftval, std::string& rightval);
bool operator== (std::string& leftval, irc::string& rightval);
bool operator== (irc::string& leftval, std::string& rightval);

std::string assign(const irc::string &other);
irc::string assign(const std::string &other);

namespace nspace
{
        /** Hashing function to hash irc::string
         */
        template<> struct hash<irc::string>
        {
                size_t operator()(const irc::string &s) const;
        };
}

#endif