runtime/TemplateRegistryKey.h

   1 /*
   2  * Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
   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. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef TemplateRegistryKey_h
  27 #define TemplateRegistryKey_h
  28
  29 #include <limits>
  30 #include <wtf/Vector.h>
  31 #include <wtf/text/StringHash.h>
  32 #include <wtf/text/WTFString.h>
  33
  34 namespace JSC {
  35
  36 class TemplateRegistryKey {
  37 public:
  38     typedef Vector<String, 4> StringVector;
  39
  40     TemplateRegistryKey(const StringVector& rawStrings, const StringVector& cookedStrings);
  41     enum DeletedValueTag { DeletedValue };
  42     TemplateRegistryKey(DeletedValueTag);
  43     enum EmptyValueTag { EmptyValue };
  44     TemplateRegistryKey(EmptyValueTag);
  45
  46     bool isDeletedValue() const { return m_rawStrings.isEmpty() && m_hash == std::numeric_limits<unsigned>::max(); }
  47
  48     bool isEmptyValue() const { return m_rawStrings.isEmpty() && !m_hash; }
  49
  50     unsigned hash() const { return m_hash; }
  51
  52     const StringVector& rawStrings() const { return m_rawStrings; }
  53     const StringVector& cookedStrings() const { return m_cookedStrings; }
  54
  55     bool operator==(const TemplateRegistryKey& other) const { return m_hash == other.m_hash && m_rawStrings == other.m_rawStrings; }
  56     bool operator!=(const TemplateRegistryKey& other) const { return m_hash != other.m_hash || m_rawStrings != other.m_rawStrings; }
  57
  58     struct Hasher {
  59         static unsigned hash(const TemplateRegistryKey& key) { return key.hash(); }
  60         static bool equal(const TemplateRegistryKey& a, const TemplateRegistryKey& b) { return a == b; }
  61         static const bool safeToCompareToEmptyOrDeleted = false;
  62     };
  63
  64 private:
  65     StringVector m_rawStrings;
  66     StringVector m_cookedStrings;
  67     unsigned m_hash { 0 };
  68 };
  69
  70 inline TemplateRegistryKey::TemplateRegistryKey(const StringVector& rawStrings, const StringVector& cookedStrings)
  71     : m_rawStrings(rawStrings)
  72     , m_cookedStrings(cookedStrings)
  73 {
  74     m_hash = 0;
  75     for (const String& string : rawStrings)
  76         m_hash += WTF::StringHash::hash(string);
  77 }
  78
  79 inline TemplateRegistryKey::TemplateRegistryKey(DeletedValueTag)
  80     : m_hash(std::numeric_limits<unsigned>::max())
  81 {
  82 }
  83
  84 inline TemplateRegistryKey::TemplateRegistryKey(EmptyValueTag)
  85     : m_hash(0)
  86 {
  87 }
  88
  89 } // namespace JSC
  90
  91 namespace WTF {
  92 template<typename T> struct DefaultHash;
  93
  94 template<> struct DefaultHash<JSC::TemplateRegistryKey> {
  95     typedef JSC::TemplateRegistryKey::Hasher Hash;
  96 };
  97
  98 template<> struct HashTraits<JSC::TemplateRegistryKey> : CustomHashTraits<JSC::TemplateRegistryKey> {
  99 };
 100
 101 } // namespace WTF
 102
 103 #endif // TemplateRegistryKey_h