parser.c

来自「mgcp协议源代码和测试程序,还有一个编译器」· C语言 代码 · 共 641 行 · 第 1/2 页

  {
    if (strncmp(ctx->pCur, string, iLen) == 0
        && ctx->pCur+iLen <= ctx->pTail) /* Avoid curren pointer over boundary */
    {
      iCount++;
      ctx->pCur += strlen(string);
    }
    else break;
  }

  if (iCount < iRepmin)
    return FAIL;
  else return OK;
}
/***************************************************************************
 * Function          : EncodeString
 *
 * Description       : Encode a string repetition into abnf message
 *                     
 * Input parameters  : ctx - pointer to encode context
 *                     iRepmin - min repeat of string
 *                     iRepmax - max repeat of string
 *                     string - string to be encoded
 *
 * Output parameters : ctx - if succeed to encode string, ctx changed
 *
 * Return value      : FAIL - fail to encode string
 *                     OK - succeed to encode string
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
int EncodeString(TCtx *ctx, int iRep, char *string)
{
  int iCount = 0;
  size_t iLen = 0;
  
  Assert(ctx);
  Assert(string);
  iLen = strlen(string);  

  while (iCount < iRep)
  {
    if (ctx->pCur+iLen <= ctx->pTail) /* Avoid curren pointer over boundary */
    {
      strncpy(ctx->pCur, string, iLen);
      iCount++;
      ctx->pCur += strlen(string);
    }
    else return FAIL;
  }

  return OK;
}
/***************************************************************************
 * Function          : ParseChar
 *
 * Description       : Parse a char repetition in abnf message
 *                     
 * Input parameters  : ctx - pointer to decode context
 *                     iRepmin - min repeat of char repetition
 *                     iRepmax - max repeat of char repetition
 *                     ValBegin - min value of char
 *                     ValEnd - max value of chat
 *
 * Output parameters : ctx - if succeed to parse, ctx changed
 *
 * Return value      : FAIL - fail to parse char
 *                     OK - succeed to parse char
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
int ParseChar(TCtx *ctx, int iRepmin, int iRepmax, unsigned char ValBegin,
                  unsigned char ValEnd)
{
  int iCount = 0;
  
  Assert(ctx);
  while (iCount < iRepmax)
  {
    if (*ctx->pCur >= ValBegin 
        && *ctx->pCur <= ValEnd
        && ctx->pCur < ctx->pTail) /* Avoid curren pointer over boundary */
    {
      iCount++;
      ctx->pCur++;
    }
    else break;
  }
  
  if (iCount < iRepmin)
    return FAIL;
  else return OK;
}
/***************************************************************************
 * Function          : EncodeChar
 *
 * Description       : encode a char repetition into abnf message
 *                     
 * Input parameters  : ctx - pointer to encode context
 *                     iRepmin - min repeat of char repetition
 *                     iRepmax - max repeat of char repetition
 *                     ValBegin - min value of char
 *                     ValEnd - max value of chat
 *
 * Output parameters : ctx - if succeed to encode, ctx changed
 *
 * Return value      : FAIL - fail to encode char
 *                     OK - succeed to encode char
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
int EncodeChar(TCtx *ctx, int iRep, unsigned char ucValue)
{
  int iCount = 0;
  
  Assert(ctx);
  while (iCount < iRep)
  {
    if (ctx->pCur < ctx->pTail) /* Avoid curren pointer over boundary */
    {
      iCount++;
      *ctx->pCur = (char)ucValue; /* Only encode the lower value into ctx */
      ctx->pCur++;
    }
    else return FAIL;
  }
  
  return OK;
}
/***************************************************************************
 * Function          : ParseToken
 *
 * Description       : Parse token repetition in abnf message
 *                     
 * Input parameters  : ctx - pointer to decode context
 *                     iRepmin - min repeat of token repetition
 *                     iRepmax - max repeat of token repetition
 *                     decfunc - pointer to token decode function
 *
 * Output parameters : ctx - if succeed to parse, ctx changed
 *
 * Return value      : FAIL - fail to parse token repetition
 *                     OK - succeed to parse token repetition
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
int ParseToken(TCtx *ctx, int iRepmin, int iRepmax, DecodeFunc decfunc)
{
  int iCount = 0;
  
  Assert(ctx);
  Assert(decfunc);
  
  while (iCount < iRepmax)
  {
    if (decfunc(ctx) == OK)
      iCount++;
    else break;
  }

  if (iCount < iRepmin)
    return FAIL;
  else return OK;
}
/***************************************************************************
 * Function          : EncodeToken
 *
 * Description       : Encode token repetition into abnf message
 *                     
 * Input parameters  : ctx - pointer to encode context
 *                     iRepmin - min repeat of token repetition
 *                     iRepmax - max repeat of token repetition
 *                     encfunc - pointer to token encode function
 *
 * Output parameters : ctx - if succeed to encode, ctx changed
 *
 * Return value      : FAIL - fail to encode token repetition
 *                     OK - succeed to encode token repetition
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
int EncodeToken(TCtx *ctx, int iRep,  EncodeFunc encfunc)
{
  int iCount = 0;
  
  Assert(ctx);
  Assert(encfunc);
  
  while (iCount < iRep)
  {
    if (encfunc(ctx) == OK)
      iCount++;
    else return FAIL;
  }

  return OK;
}
/***************************************************************************
 * Function          : AbnfStrnClone
 *
 * Description       : Copy n chars into a new allocate string from the src string
 *                     
 * Input parameters  : ctx - pointer to ctx
 *                     Head - pointer to header char to be copied
 *                     Tail - pointer to tail char to be copied
 *
 * Output parameters : ctx - store the allocate memory pointer
 *
 * Return value      : If succeed, return the pointer of the new string;
 *                     If fail, return NULL
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
char* AbnfStrnClone(TCtx *ctx, char *Head, char *Tail)
{
  char *pTmp = NULL;
  int iLen = Tail - Head;
  
  Assert(ctx);
  Assert(Head);
  Assert(Tail);
  if (iLen > 0)
  {
    if ((pTmp = (char*)AbnfAlloc(ctx, (size_t)iLen+1)) != NULL)
    {
      strncpy(pTmp, Head, (size_t)iLen);
      pTmp[iLen] = '\0';
    }
  }

  return pTmp;
}
/***************************************************************************
 * Function          : ParseStrRule
 *
 * Description       : Parse a StringRule repetition in abnf message
 *                     
 * Input parameters  : ctx - pointer to decode context
 *                     iRepmin - min repeat of repetition
 *                     iRepmax - max repeat of repetition
 *                     ppdata - pointer to a string point which pointe to
 *                              the parse result
 *                     decfunc - pointer of decode function
 *
 * Output parameters : ctx - if succeed to parse, ctx changed
 *                     ppdata - if succeed to parse, create a new string
 *                              and return the sting pointer, otherwise 
 *                              return NULL
 *
 * Return value      : FAIL - fail to parse string
 *                     OK - succeed to parse string
 *
 * Comments          : 
 *
 * History           :
 *  2005/04/10       : Creation
 *
 * Date              : April 10 2005, Frank Zhang
 **************************************************************************/
int ParseStrRule(TCtx *ctx, char **ppdata, int iRepmin, int iRepmax, DecodeFunc decfunc)
{
  int iCount = 0;

  /* Save the entry pointer */
  char *pEntry = ctx->pCur;
  
  Assert(ctx);
  Assert(ppdata);
  Assert(decfunc);
  
  while (iCount < iRepmax)
  {
    if (decfunc(ctx) == OK)
      iCount++;
    else break;
  }
  
  if (iCount < iRepmin)
  {
    *ppdata = NULL;
    return FAIL;
  }

  *ppdata= AbnfStrnClone(ctx, pEntry, ctx->pCur);
  return OK;
}