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27 #include "SmallStrings.h"
29 #include "HeapRootVisitor.h"
30 #include "JSGlobalObject.h"
32 #include <wtf/Noncopyable.h>
33 #include <wtf/PassOwnPtr.h>
37 static inline void finalize(JSString*& string)
39 if (!string || Heap::isMarked(string))
44 class SmallStringsStorage {
45 WTF_MAKE_NONCOPYABLE(SmallStringsStorage); WTF_MAKE_FAST_ALLOCATED;
47 SmallStringsStorage();
49 StringImpl* rep(unsigned char character)
51 return m_reps[character].get();
55 static const unsigned singleCharacterStringCount = maxSingleCharacterString + 1;
57 RefPtr<StringImpl> m_reps[singleCharacterStringCount];
60 SmallStringsStorage::SmallStringsStorage()
62 UChar* characterBuffer = 0;
63 RefPtr<StringImpl> baseString = StringImpl::createUninitialized(singleCharacterStringCount, characterBuffer);
64 for (unsigned i = 0; i < singleCharacterStringCount; ++i) {
65 characterBuffer[i] = i;
66 m_reps[i] = StringImpl::create(baseString, i, 1);
70 SmallStrings::SmallStrings()
72 COMPILE_ASSERT(singleCharacterStringCount == sizeof(m_singleCharacterStrings) / sizeof(m_singleCharacterStrings[0]), IsNumCharactersConstInSyncWithClassUsage);
76 SmallStrings::~SmallStrings()
80 void SmallStrings::finalizeSmallStrings()
82 finalize(m_emptyString);
83 for (unsigned i = 0; i < singleCharacterStringCount; ++i)
84 finalize(m_singleCharacterStrings[i]);
87 void SmallStrings::clear()
90 for (unsigned i = 0; i < singleCharacterStringCount; ++i)
91 m_singleCharacterStrings[i] = 0;
94 unsigned SmallStrings::count() const
99 for (unsigned i = 0; i < singleCharacterStringCount; ++i) {
100 if (m_singleCharacterStrings[i])
106 void SmallStrings::createEmptyString(JSGlobalData* globalData)
108 ASSERT(!m_emptyString);
109 m_emptyString = JSString::createHasOtherOwner(*globalData, "");
112 void SmallStrings::createSingleCharacterString(JSGlobalData* globalData, unsigned char character)
115 m_storage = adoptPtr(new SmallStringsStorage);
116 ASSERT(!m_singleCharacterStrings[character]);
117 m_singleCharacterStrings[character] = JSString::createHasOtherOwner(*globalData, PassRefPtr<StringImpl>(m_storage->rep(character)));
120 StringImpl* SmallStrings::singleCharacterStringRep(unsigned char character)
123 m_storage = adoptPtr(new SmallStringsStorage);
124 return m_storage->rep(character);