pike.git/ src/ builtin_functions.c

Branch: Tag:

2003-11-09

2003-11-09 23:59:14 by Martin Stjernholm <mast@lysator.liu.se>

Added a function hash_value to access the hashing method for mappings.

Rev: src/builtin_functions.c:1.518

2:   || This file is part of Pike. For copyright information see COPYRIGHT.   || Pike is distributed under GPL, LGPL and MPL. See the file COPYING   || for more information. - || $Id: builtin_functions.c,v 1.517 2003/11/07 21:28:07 mast Exp $ + || $Id: builtin_functions.c,v 1.518 2003/11/09 23:59:14 mast Exp $   */      #include "global.h" - RCSID("$Id: builtin_functions.c,v 1.517 2003/11/07 21:28:07 mast Exp $"); + RCSID("$Id: builtin_functions.c,v 1.518 2003/11/09 23:59:14 mast Exp $");   #include "interpret.h"   #include "svalue.h"   #include "pike_macros.h"
116:   /*! @decl int hash_7_4(string s)    *! @decl int hash_7_4(string s, int max)    *! -  *! This function will return an @expr{int@} derived from the string @[s]. -  *! The same string will always hash to the same value. -  *! If @[max] is given, the result will be >= 0 and < @[max], otherwise -  *! the result will be >= 0 and <= 0x7fffffff. +  *! Return an integer derived from the string @[s]. The same string +  *! will always hash to the same value, also between processes.    *! -  +  *! If @[max] is given, the result will be >= 0 and < @[max], +  *! otherwise the result will be >= 0 and <= 0x7fffffff. +  *!    *! @note    *! This function is provided for backward compatibility reasons.    *! -  *! This function is byte-order dependant. +  *! This function is byte-order dependant for wide strings.    *!    *! @seealso    *! @[hash()], @[hash_7_0()]
160:   /*! @decl int hash_7_0(string s)    *! @decl int hash_7_0(string s, int max)    *! -  *! This function will return an @expr{int@} derived from the string @[s]. -  *! The same string will always hash to the same value. -  *! If @[max] is given, the result will be >= 0 and < @[max], otherwise -  *! the result will be >= 0 and <= 0x7fffffff. +  *! Return an integer derived from the string @[s]. The same string +  *! always hashes to the same value, also between processes.    *! -  +  *! If @[max] is given, the result will be >= 0 and < @[max], +  *! otherwise the result will be >= 0 and <= 0x7fffffff. +  *!    *! @note    *! This function is provided for backward compatibility reasons.    *!
207:   /*! @decl int hash(string s)    *! @decl int hash(string s, int max)    *! -  *! This function will return an @expr{int@} derived from the string @[s]. -  *! The same string will always hash to the same value. -  *! If @[max] is given, the result will be >= 0 and < @[max], otherwise -  *! the result will be >= 0 and <= 0x7fffffff. +  *! Return an integer derived from the string @[s]. The same string +  *! always hashes to the same value, also between processes, +  *! architectures, and Pike versions (see compatibility notes below, +  *! though).    *! -  +  *! If @[max] is given, the result will be >= 0 and < @[max], +  *! otherwise the result will be >= 0 and <= 0x7fffffff. +  *!    *! @note    *! The hash algorithm was changed in Pike 7.5. If you want a hash    *! that is compatible with Pike 7.4 and earlier, use @[hash_7_4()]. -  +  *! The difference only affects wide strings.    *!    *! The hash algorithm was also changed in Pike 7.1. If you want a hash    *! that is compatible with Pike 7.0 and earlier, use @[hash_7_0()].    *!    *! @seealso -  *! @[hash_7_0()], @[hash_7_4()] +  *! @[hash_7_0()], @[hash_7_4()], @[hash_value]    */   PMOD_EXPORT void f_hash(INT32 args)   {
266:    push_int64(i);   }    + /*! @decl int hash_value (mixed value) +  *! +  *! Return a hash value for the argument. It's an integer in the +  *! native integer range. +  *! +  *! The hash will be the same for the same value in the running +  *! process only (the memory address is typically used as the basis +  *! for the hash value). +  *! +  *! If the value is an object with an @[lfun::__hash], that function +  *! is called and its result is returned. +  *! +  *! @note +  *! This is the hashing method used by mappings. +  *! +  *! @seealso +  *! @[hash] +  */ + void f_hash_value(INT32 args) + { +  unsigned INT32 h; +  +  if(!args) +  SIMPLE_TOO_FEW_ARGS_ERROR("hash_value",1); +  +  h = hash_svalue (Pike_sp - args); +  pop_n_elems (args); +  push_int (h); + } +    /*! @decl mixed copy_value(mixed value)    *!    *! Copy a value recursively.
8015:    ADD_EFUN("hash_7_4",f_hash_7_4,    tFunc(tStr tOr(tInt,tVoid),tInt),OPT_TRY_OPTIMIZE);    +  ADD_EFUN("hash_value",f_hash_value,tFunc(tMix,tInt),OPT_TRY_OPTIMIZE); +    /* function(string|array:int*)|function(mapping(1=mixed:mixed)|multiset(1=mixed):array(1))|function(object|program:string*) */    ADD_EFUN2("indices",f_indices,    tOr3(tFunc(tOr(tStr,tArray),tArr(tInt)),