xpcom/string/src/nsTSubstringTuple.cpp

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  22  * Contributor(s):
  23  *   Darin Fisher <darin@meer.net>
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  38
  39
  40   /**
  41    * computes the aggregate string length
  42    */
  43
  44 nsTSubstringTuple_CharT::size_type
  45 nsTSubstringTuple_CharT::Length() const
  46   {
  47     PRUint32 len;
  48     if (mHead)
  49       len = mHead->Length();
  50     else
  51       len = TO_SUBSTRING(mFragA).Length();
  52
  53     return len + TO_SUBSTRING(mFragB).Length();
  54   }
  55
  56
  57   /**
  58    * writes the aggregate string to the given buffer.  bufLen is assumed
  59    * to be equal to or greater than the value returned by the Length()
  60    * method.  the string written to |buf| is not null-terminated.
  61    */
  62
  63 void
  64 nsTSubstringTuple_CharT::WriteTo( char_type *buf, PRUint32 bufLen ) const
  65   {
  66     const substring_type& b = TO_SUBSTRING(mFragB);
  67
  68     NS_ASSERTION(bufLen >= b.Length(), "buffer too small");
  69     PRUint32 headLen = bufLen - b.Length();
  70     if (mHead)
  71       {
  72         mHead->WriteTo(buf, headLen);
  73       }
  74     else
  75       {
  76         const substring_type& a = TO_SUBSTRING(mFragA);
  77
  78         NS_ASSERTION(a.Length() == headLen, "buffer incorrectly sized");
  79         char_traits::copy(buf, a.Data(), a.Length());
  80       }
  81
  82     char_traits::copy(buf + headLen, b.Data(), b.Length());
  83
  84 #if 0
  85     // we need to write out data into |buf|, ending at |buf+bufLen|.  so our
  86     // data needs to precede |buf+bufLen| exactly.  we trust that the buffer
  87     // was properly sized!
  88
  89     const substring_type& b = TO_SUBSTRING(mFragB);
  90
  91     NS_ASSERTION(bufLen >= b.Length(), "buffer is too small");
  92     char_traits::copy(buf + bufLen - b.Length(), b.Data(), b.Length());
  93
  94     bufLen -= b.Length();
  95
  96     if (mHead)
  97       {
  98         mHead->WriteTo(buf, bufLen);
  99       }
 100     else
 101       {
 102         const substring_type& a = TO_SUBSTRING(mFragA);
 103         NS_ASSERTION(bufLen == a.Length(), "buffer is too small");
 104         char_traits::copy(buf, a.Data(), a.Length());
 105       }
 106 #endif
 107   }
 108
 109
 110   /**
 111    * returns true if this tuple is dependent on (i.e., overlapping with)
 112    * the given char sequence.
 113    */
 114
 115 PRBool
 116 nsTSubstringTuple_CharT::IsDependentOn( const char_type *start, const char_type *end ) const
 117   {
 118     // we start with the right-most fragment since it is faster to check.
 119
 120     if (TO_SUBSTRING(mFragB).IsDependentOn(start, end))
 121       return PR_TRUE;
 122
 123     if (mHead)
 124       return mHead->IsDependentOn(start, end);
 125
 126     return TO_SUBSTRING(mFragA).IsDependentOn(start, end);
 127   }