1 files changed, 96 insertions, 0 deletions
diff --git a/xpcom/string/nsTSubstringTuple.cpp b/xpcom/string/nsTSubstringTuple.cpp
new file mode 100644
index 000000000..2a84a9a4e
--- /dev/null
+++ b/xpcom/string/nsTSubstringTuple.cpp
@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/CheckedInt.h"
+
+/**
+ * computes the aggregate string length
+ */
+
+nsTSubstringTuple_CharT::size_type
+nsTSubstringTuple_CharT::Length() const
+{
+  mozilla::CheckedInt<size_type> len;
+  if (mHead) {
+    len = mHead->Length();
+  } else {
+    len = TO_SUBSTRING(mFragA).Length();
+  }
+
+  len += TO_SUBSTRING(mFragB).Length();
+  MOZ_RELEASE_ASSERT(len.isValid(), "Substring tuple length is invalid");
+  return len.value();
+}
+
+
+/**
+ * writes the aggregate string to the given buffer. aBufLen is assumed
+ * to be equal to or greater than the value returned by the Length()
+ * method.  the string written to |aBuf| is not null-terminated.
+ */
+
+void
+nsTSubstringTuple_CharT::WriteTo(char_type* aBuf, uint32_t aBufLen) const
+{
+  const substring_type& b = TO_SUBSTRING(mFragB);
+
+  MOZ_RELEASE_ASSERT(aBufLen >= b.Length(), "buffer too small");
+  uint32_t headLen = aBufLen - b.Length();
+  if (mHead) {
+    mHead->WriteTo(aBuf, headLen);
+  } else {
+    const substring_type& a = TO_SUBSTRING(mFragA);
+
+    MOZ_RELEASE_ASSERT(a.Length() == headLen, "buffer incorrectly sized");
+    char_traits::copy(aBuf, a.Data(), a.Length());
+  }
+
+  char_traits::copy(aBuf + headLen, b.Data(), b.Length());
+
+#if 0
+  // we need to write out data into |aBuf|, ending at |aBuf + aBufLen|. So our
+  // data needs to precede |aBuf + aBufLen| exactly. We trust that the buffer
+  // was properly sized!
+
+  const substring_type& b = TO_SUBSTRING(mFragB);
+
+  NS_ASSERTION(aBufLen >= b.Length(), "buffer is too small");
+  char_traits::copy(aBuf + aBufLen - b.Length(), b.Data(), b.Length());
+
+  aBufLen -= b.Length();
+
+  if (mHead) {
+    mHead->WriteTo(aBuf, aBufLen);
+  } else {
+    const substring_type& a = TO_SUBSTRING(mFragA);
+    NS_ASSERTION(aBufLen == a.Length(), "buffer is too small");
+    char_traits::copy(aBuf, a.Data(), a.Length());
+  }
+#endif
+}
+
+
+/**
+ * returns true if this tuple is dependent on (i.e., overlapping with)
+ * the given char sequence.
+ */
+
+bool
+nsTSubstringTuple_CharT::IsDependentOn(const char_type* aStart,
+                                       const char_type* aEnd) const
+{
+  // we aStart with the right-most fragment since it is faster to check.
+
+  if (TO_SUBSTRING(mFragB).IsDependentOn(aStart, aEnd)) {
+    return true;
+  }
+
+  if (mHead) {
+    return mHead->IsDependentOn(aStart, aEnd);
+  }
+
+  return TO_SUBSTRING(mFragA).IsDependentOn(aStart, aEnd);
+}