xpcom/string/nsTSubstringTuple.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7
   8 /**
   9  * computes the aggregate string length
  10  */
  11
  12 nsTSubstringTuple_CharT::size_type
  13 nsTSubstringTuple_CharT::Length() const
  14 {
  15   uint32_t len;
  16   if (mHead) {
  17     len = mHead->Length();
  18   } else {
  19     len = TO_SUBSTRING(mFragA).Length();
  20   }
  21
  22   return len + TO_SUBSTRING(mFragB).Length();
  23 }
  24
  25
  26 /**
  27  * writes the aggregate string to the given buffer. aBufLen is assumed
  28  * to be equal to or greater than the value returned by the Length()
  29  * method.  the string written to |aBuf| is not null-terminated.
  30  */
  31
  32 void
  33 nsTSubstringTuple_CharT::WriteTo(char_type* aBuf, uint32_t aBufLen) const
  34 {
  35   const substring_type& b = TO_SUBSTRING(mFragB);
  36
  37   NS_ASSERTION(aBufLen >= b.Length(), "buffer too small");
  38   uint32_t headLen = aBufLen - b.Length();
  39   if (mHead) {
  40     mHead->WriteTo(aBuf, headLen);
  41   } else {
  42     const substring_type& a = TO_SUBSTRING(mFragA);
  43
  44     NS_ASSERTION(a.Length() == headLen, "buffer incorrectly sized");
  45     char_traits::copy(aBuf, a.Data(), a.Length());
  46   }
  47
  48   char_traits::copy(aBuf + headLen, b.Data(), b.Length());
  49
  50 #if 0
  51   // we need to write out data into |aBuf|, ending at |aBuf + aBufLen|. So our
  52   // data needs to precede |aBuf + aBufLen| exactly. We trust that the buffer
  53   // was properly sized!
  54
  55   const substring_type& b = TO_SUBSTRING(mFragB);
  56
  57   NS_ASSERTION(aBufLen >= b.Length(), "buffer is too small");
  58   char_traits::copy(aBuf + aBufLen - b.Length(), b.Data(), b.Length());
  59
  60   aBufLen -= b.Length();
  61
  62   if (mHead) {
  63     mHead->WriteTo(aBuf, aBufLen);
  64   } else {
  65     const substring_type& a = TO_SUBSTRING(mFragA);
  66     NS_ASSERTION(aBufLen == a.Length(), "buffer is too small");
  67     char_traits::copy(aBuf, a.Data(), a.Length());
  68   }
  69 #endif
  70 }
  71
  72
  73 /**
  74  * returns true if this tuple is dependent on (i.e., overlapping with)
  75  * the given char sequence.
  76  */
  77
  78 bool
  79 nsTSubstringTuple_CharT::IsDependentOn(const char_type* aStart,
  80                                        const char_type* aEnd) const
  81 {
  82   // we aStart with the right-most fragment since it is faster to check.
  83
  84   if (TO_SUBSTRING(mFragB).IsDependentOn(aStart, aEnd)) {
  85     return true;
  86   }
  87
  88   if (mHead) {
  89     return mHead->IsDependentOn(aStart, aEnd);
  90   }
  91
  92   return TO_SUBSTRING(mFragA).IsDependentOn(aStart, aEnd);
  93 }