runtime/RegExpCachedResult.h

   1 /*
   2  * Copyright (C) 2012 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 RegExpCachedResult_h
  27 #define RegExpCachedResult_h
  28
  29 #include "RegExpObject.h"
  30
  31 namespace JSC {
  32
  33 class JSArray;
  34 class JSString;
  35
  36 // RegExpCachedResult is used to track the cached results of the last
  37 // match, stores on the RegExp constructor (e.g. $&, $_, $1, $2 ...).
  38 // These values will be lazily generated on demand, so the cached result
  39 // may be in a lazy or reified state. A lazy state is indicated by a
  40 // value of m_result indicating a successful match, and a reified state
  41 // is indicated by setting m_result to MatchResult::failed().
  42 // Following a successful match, m_result, m_lastInput and m_lastRegExp
  43 // can be used to reify the results from the match, following reification
  44 // m_reifiedResult and m_reifiedInput hold the cached results.
  45 class RegExpCachedResult {
  46 public:
  47     RegExpCachedResult(VM& vm, JSObject* owner, RegExp* emptyRegExp)
  48         : m_result(0, 0)
  49         , m_reified(false)
  50     {
  51         m_lastInput.set(vm, owner, jsEmptyString(&vm));
  52         m_lastRegExp.set(vm, owner, emptyRegExp);
  53     }
  54
  55     ALWAYS_INLINE void record(VM& vm, JSObject* owner, RegExp* regExp, JSString* input, MatchResult result)
  56     {
  57         m_lastRegExp.set(vm, owner, regExp);
  58         m_lastInput.set(vm, owner, input);
  59         m_reifiedLeftContext.clear();
  60         m_reifiedRightContext.clear();
  61         m_result = result;
  62         m_reified = false;
  63     }
  64
  65     JSArray* lastResult(ExecState*, JSObject* owner);
  66     void setInput(ExecState*, JSObject* owner, JSString*);
  67
  68     JSString* leftContext(ExecState*, JSObject* owner);
  69     JSString* rightContext(ExecState*, JSObject* owner);
  70
  71     JSString* input()
  72     {
  73         return m_reified ? m_reifiedInput.get() : m_lastInput.get();
  74     }
  75
  76     void visitChildren(SlotVisitor&);
  77
  78 private:
  79     MatchResult m_result;
  80     bool m_reified;
  81     WriteBarrier<JSString> m_lastInput;
  82     WriteBarrier<RegExp> m_lastRegExp;
  83     WriteBarrier<JSArray> m_reifiedResult;
  84     WriteBarrier<JSString> m_reifiedInput;
  85     WriteBarrier<JSString> m_reifiedLeftContext;
  86     WriteBarrier<JSString> m_reifiedRightContext;
  87 };
  88
  89 } // namespace JSC
  90
  91 #endif // RegExpCachedResult_h