runtime/JSStringJoiner.h

   1 /*
   2  * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef JSStringJoiner_h
  27 #define JSStringJoiner_h
  28
  29 #include "JSCJSValue.h"
  30 #include <wtf/Vector.h>
  31 #include <wtf/text/WTFString.h>
  32
  33 namespace JSC {
  34
  35 class ExecState;
  36
  37
  38 class JSStringJoiner {
  39 public:
  40     JSStringJoiner(const String& separator, size_t stringCount);
  41
  42     void append(const String&);
  43     JSValue join(ExecState*);
  44
  45 private:
  46     String m_separator;
  47     Vector<String> m_strings;
  48
  49     Checked<unsigned, RecordOverflow> m_accumulatedStringsLength;
  50     bool m_isValid;
  51     bool m_is8Bits;
  52 };
  53
  54 inline JSStringJoiner::JSStringJoiner(const String& separator, size_t stringCount)
  55     : m_separator(separator)
  56     , m_isValid(true)
  57     , m_is8Bits(m_separator.is8Bit())
  58 {
  59     ASSERT(!m_separator.isNull());
  60     m_isValid = m_strings.tryReserveCapacity(stringCount);
  61 }
  62
  63 inline void JSStringJoiner::append(const String& str)
  64 {
  65     if (!m_isValid)
  66         return;
  67
  68     m_strings.append(str);
  69     if (!str.isNull()) {
  70         m_accumulatedStringsLength += str.length();
  71         m_is8Bits = m_is8Bits && str.is8Bit();
  72     }
  73 }
  74
  75 }
  76
  77 #endif