/********************************************************************20**

     Name:     common library functions
  
     Type:     C source file
  
     Desc:     Common functions that are implemented in
               both a portable and a performance-efficient manner. These
               functions are selected based on the operating system.

     File:     cm_lib.c

     Sid:      cm_lib.c@@/main/10 - Fri Feb  9 16:23:51 2001

     Prg:      ak

*********************************************************************21*/

/***********************************************************************
 * This file provides memory and string library functions implemented in
 * one of two ways:
 *
 *     1. portable: does not assume library support for any of the functions
 *                  needed.
 *
 *     2. using environment specific: this uses existing library
 *        functions and is therefore, for an environment where such
 *        functionality is available and , a more desirable choice!
 *
 *  The following functions are available in this file:
 *
 *       1. cmMemcpy: copies specified number of octets from one memory
 *          location to another.
 *       2. cmMemcmp: compares specified number of octets at one memory
 *          locaton with the same number from another.
 *       3. cmMemset: sets specified number of octets starting at given
 *          memory location with the given value.
 *       4. cmStrCmp: compares two strings, until the '\0' character is
 *          encountered.
 *       5. cmStrncmp: compares two strings, until \0 is encountered or
 *          until the specified length is exceeded.
 *       6. cmStrlen: finds length of a string until the \0 character.
 *
 *  The following flags are used in this file:
 *
 *     1. DONT_USE_SYS_LIB: If defined, this will compile in the portable
 *        versions of each function in this file. This overrides all other
 *        flags defined in this file.
 *
 *  For the SOLARIS environment:
 *
 *     The functionality defined in this file is generally available as library
 *     functions in the native operating systems' libraries. We have provided
 *     the functionality using the SOLARIS libraries, in this file.
 *
 *     If you want to take advantage of these library functions, all you need
 *     to do is the following:
 *
 *     1. Do not turn on the DONT_USE_SYS_LIB flag.
 *     2. Turn on the SUNOS51 flag.
 *
 *     This, in turn, turns on the following flags
 *
 *        1. MEMCPY_AVAIL  : maps cmMemcpy to C library function memcpy
 *        2. MEMCMP_AVAIL  : maps cmMemcmp to C library function memcmp
 *        3. MEMSET_AVAIL  : maps cmMemset to C library function memset
 *        4. STRCMP_AVAIL  : maps cmStrcmp to Strings library function strcmp
 *        5. STRNCMP_AVAIL : maps cmStrncmp to Strings library function strncmp
 *        5. STRLEN_AVAIL  : maps cmStrlen to Strings library function strlen
 *
 *  For an environment different from SOLARIS:
 *        
 *    You will need to modify this file to do more or less the same stuff
 *    as has been done for Solaris. i.e.
 *
 *     1. create a section inside the #ifndef DONT_USE_SYS_LIB section
 *        similar to the #ifdef SUNOS51 section that:
 *             1. includes system header files.
 *             2. defines MEMCPY_AVAIL etc. as needed.
 *     2. modify code inside functions to make use of the system library
 *        primitive.
 *     3. communicate your changes to Trillium so they can be incorporated
 *        in the next release of this file
 *
 *  To add a new library primitive to this file:
 *     1. it should be implemented in both a portable and environment specific
 *        manner.
 *     2. the portable implementation will not be the default
 *     3. the portable version and the environment specif versions must be
 *        enclosed in #ifdef XXXXXX_AVAIL
 *                     <environment specific implementation>
 *                    #else
 *                     <portable implementation>
 *                    #endif
 *     4. It must be communicated to Trillium so it will be included in the
 *        next release of the file.
 *     5. Trillium engineering must have all changes approved by engineering
 *        management.
 *     6. Trillium reserves the right to not incorporate any changes submitted
 *        by customers, if not approved by Trillium engineering management.
 *     7. Trillium reserves the right to modify code submitted by customers to
 *        enhance this file.
 ************************************************************************/


#ifndef DONT_USE_SYS_LIB

#define MEMCPY_AVAIL   1
#define MEMCMP_AVAIL   1
#define MEMSET_AVAIL   1
#define STRCMP_AVAIL   1
#define STRNCMP_AVAIL  1
#define STRLEN_AVAIL   1

#else  /* DONT_USE_SYS_LIB */
#define MEMCPY_AVAIL   0
#define MEMCMP_AVAIL   0
#define MEMSET_AVAIL   0
#define STRCMP_AVAIL   0
#define STRNCMP_AVAIL  0
#define STRLEN_AVAIL   0
#endif /* not DONT_USE_SYS_LIB */


#include "envopt.h"        /* environment options */
#include "envind.h"        /* environment options */
#include "envdep.h"        /* environment options */
 
#include "gen.h"           /* general layer */
#include "ssi.h"           /* system services */

/* header/extern include files (.x) */
 
#include "gen.x"           /* general layer */
#include "ssi.x"           /* system services */
#include "cm_lib.x"        /* prototypes of primitives in this file */


#include "stdio.h"
#include "ctype.h"
#include "stdlib.h"
#include "string.h"

#if (ERRCLASS & ERRCLS_DEBUG)

#define ECMLIBBASE     0
#define ECMLIB001      ECMLIBBASE + 1
#define ECMLIB002      ECMLIBBASE + 2
#define ECMLIB003      ECMLIBBASE + 3
#define ECMLIB004      ECMLIBBASE + 4
#define ECMLIB005      ECMLIBBASE + 5
#define ECMLIB006      ECMLIBBASE + 6
#define ECMLIB007      ECMLIBBASE + 7

#define CMLIBERR(_eCode, _eVal, _eDesc) \
    SLogError ((Ent) 0, (Inst)0, (ProcId)0, __FILE__, __LINE__, \
               (ErrCls)ERRCLS_DEBUG, (ErrCode)_eCode, (ErrVal) _eVal, \
               (Txt *) _eDesc)
#else
#define CMLIBERR(_eCode, _eVal, _eDesc)
#endif


/*
*
*       Fun:   cmMemcpy
*
*       Desc:  common primitive to copy a contiguous string of bytes
*              optimized for when memcpy is available. It uses memcpy
*              when available. Otherwise, copies in a 'for' loop.
*
*              sets "len" memory locations starting from "tgt" to the values
*              of corresponding memory locations starting from "src".
*
*       Ret:   pointer to target string
*
*       Notes: None
*
*       File:  cm_lib.c
*
*/
#ifdef ANSI
PUBLIC U8 *cmMemcpy
(
U8           *tgt,
CONSTANT U8  *src,
PTR          len
)
#else
PUBLIC U8 *cmMemcpy(tgt, src, len)
U8           *tgt;
CONSTANT U8  *src;
PTR          len;
#endif
{
#if (MEMCPY_AVAIL) /* memcpy is available */
   RETVALUE((U8 *) memcpy((Void *)tgt, (CONSTANT Void *)src, (size_t)len));
#else
   while (len--)
      *tgt++ = *src++;

   RETVALUE(tgt);
#endif /* MEMCPY_AVAIL */

} /* end of cmMemcpy */


/*
*
*       Fun:   cmMemcmp
*
*       Desc:  common primitive to compare a contiguous string of bytes
*              optimized for when memcmp is available. It uses memcmp
*              when available. Otherwise, compares in a 'for' loop.
*
*       Ret:    < 0 => s1 < s2
*               > 0 => s1 > s2
*               = 0 => s1 = s2
*
*       Notes: None
*
*       File:  cm_lib.c
*
*/
#ifdef ANSI
PUBLIC S16 cmMemcmp
(
CONSTANT U8     *s1,
CONSTANT U8     *s2,
PTR             len
)
#else
PUBLIC S16 cmMemcmp (s1, s2, len)
CONSTANT U8     *s1;
CONSTANT U8     *s2;
PTR             len;
#endif
{
#if MEMCMP_AVAIL /* memcmp is available */
   RETVALUE((S16) memcmp((CONSTANT Void *)s1, (CONSTANT Void *)s2, (size_t)len));
#else  /* MEMCMP_AVAIL: memcmp is not available */
   while (len--)
   {
      if (*s1 ^ *s2)
         RETVALUE((S16) (*s1 - *s2));
      s1++;
      s2++;
   }
   RETVALUE(0);
#endif /* MEMCMP_AVAIL */
} /* end of cmMemcmp */


/*
*
*       Fun:   cmMemset
*
*       Desc:  common primitive to set a contiguous string of bytes
*              with a specified value optimized for when memset is available.
*              It uses memset when available. Otherwise, uses a 'for' loop.
*
*              sets "len" memory locations starting from "str" to the value
*              "val".
* 
*       Ret:   pointer to string
*
*       Notes: None
*
*       File:  cm_lib.c