blob: 2755e5442a953884f5d82c2d2c06fa5d49e5d985 [file] [log] [blame]
/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* Copyright (C) 2005-2017 Apple Inc. All rights reserved.
* Copyright (C) 2009 Google Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef StringImpl_h
#define StringImpl_h
#include <limits.h>
#include <unicode/uchar.h>
#include <unicode/ustring.h>
#include <wtf/ASCIICType.h>
#include <wtf/CheckedArithmetic.h>
#include <wtf/Forward.h>
#include <wtf/Hasher.h>
#include <wtf/MathExtras.h>
#include <wtf/StdLibExtras.h>
#include <wtf/Vector.h>
#include <wtf/text/ConversionMode.h>
#include <wtf/text/StringCommon.h>
#if USE(CF)
typedef const struct __CFString * CFStringRef;
#endif
#ifdef __OBJC__
@class NSString;
#endif
namespace JSC {
namespace LLInt { class Data; }
class LLIntOffsetsExtractor;
}
namespace WTF {
class SymbolImpl;
class SymbolRegistry;
struct CStringTranslator;
template<typename> struct BufferFromStaticDataTranslator;
struct HashAndUTF8CharactersTranslator;
struct LCharBufferTranslator;
struct StringHash;
struct SubstringTranslator;
struct UCharBufferTranslator;
template<typename> class RetainPtr;
template<typename> struct HashAndCharactersTranslator;
enum TextCaseSensitivity {
TextCaseSensitive,
TextCaseInsensitive
};
typedef bool (*CharacterMatchFunctionPtr)(UChar);
typedef bool (*IsWhiteSpaceFunctionPtr)(UChar);
// Define STRING_STATS to 1 turn on run time statistics of string sizes and memory usage
#define STRING_STATS 0
#if STRING_STATS
struct StringStats {
inline void add8BitString(unsigned length, bool isSubString = false)
{
++m_totalNumberStrings;
++m_number8BitStrings;
if (!isSubString)
m_total8BitData += length;
}
inline void add16BitString(unsigned length, bool isSubString = false)
{
++m_totalNumberStrings;
++m_number16BitStrings;
if (!isSubString)
m_total16BitData += length;
}
void removeString(StringImpl&);
void printStats();
static const unsigned s_printStringStatsFrequency = 5000;
static std::atomic<unsigned> s_stringRemovesTillPrintStats;
std::atomic<unsigned> m_refCalls;
std::atomic<unsigned> m_derefCalls;
std::atomic<unsigned> m_totalNumberStrings;
std::atomic<unsigned> m_number8BitStrings;
std::atomic<unsigned> m_number16BitStrings;
std::atomic<unsigned long long> m_total8BitData;
std::atomic<unsigned long long> m_total16BitData;
};
#define STRING_STATS_ADD_8BIT_STRING(length) StringImpl::stringStats().add8BitString(length)
#define STRING_STATS_ADD_8BIT_STRING2(length, isSubString) StringImpl::stringStats().add8BitString(length, isSubString)
#define STRING_STATS_ADD_16BIT_STRING(length) StringImpl::stringStats().add16BitString(length)
#define STRING_STATS_ADD_16BIT_STRING2(length, isSubString) StringImpl::stringStats().add16BitString(length, isSubString)
#define STRING_STATS_REMOVE_STRING(string) StringImpl::stringStats().removeString(string)
#define STRING_STATS_REF_STRING(string) ++StringImpl::stringStats().m_refCalls;
#define STRING_STATS_DEREF_STRING(string) ++StringImpl::stringStats().m_derefCalls;
#else
#define STRING_STATS_ADD_8BIT_STRING(length) ((void)0)
#define STRING_STATS_ADD_8BIT_STRING2(length, isSubString) ((void)0)
#define STRING_STATS_ADD_16BIT_STRING(length) ((void)0)
#define STRING_STATS_ADD_16BIT_STRING2(length, isSubString) ((void)0)
#define STRING_STATS_ADD_UPCONVERTED_STRING(length) ((void)0)
#define STRING_STATS_REMOVE_STRING(string) ((void)0)
#define STRING_STATS_REF_STRING(string) ((void)0)
#define STRING_STATS_DEREF_STRING(string) ((void)0)
#endif
class StringImplShape {
WTF_MAKE_NONCOPYABLE(StringImplShape);
protected:
StringImplShape(unsigned refCount, unsigned length, const LChar* data8, unsigned hashAndFlags)
: m_refCount(refCount)
, m_length(length)
, m_data8(data8)
, m_hashAndFlags(hashAndFlags)
{ }
StringImplShape(unsigned refCount, unsigned length, const UChar* data16, unsigned hashAndFlags)
: m_refCount(refCount)
, m_length(length)
, m_data16(data16)
, m_hashAndFlags(hashAndFlags)
{ }
enum ConstructWithConstExprTag { ConstructWithConstExpr };
template<unsigned characterCount>
constexpr StringImplShape(unsigned refCount, unsigned length, const char (&characters)[characterCount], unsigned hashAndFlags, ConstructWithConstExprTag)
: m_refCount(refCount)
, m_length(length)
, m_data8Char(characters)
, m_hashAndFlags(hashAndFlags)
{ }
template<unsigned characterCount>
constexpr StringImplShape(unsigned refCount, unsigned length, const char16_t (&characters)[characterCount], unsigned hashAndFlags, ConstructWithConstExprTag)
: m_refCount(refCount)
, m_length(length)
, m_data16Char(characters)
, m_hashAndFlags(hashAndFlags)
{ }
unsigned m_refCount;
unsigned m_length;
union {
const LChar* m_data8;
const UChar* m_data16;
// It seems that reinterpret_cast prevents constexpr's compile time initialization in VC++.
// These are needed to avoid reinterpret_cast.
const char* m_data8Char;
const char16_t* m_data16Char;
};
mutable unsigned m_hashAndFlags;
};
class StringImpl : private StringImplShape {
WTF_MAKE_NONCOPYABLE(StringImpl); WTF_MAKE_FAST_ALLOCATED;
friend struct WTF::CStringTranslator;
template<typename CharacterType> friend struct WTF::HashAndCharactersTranslator;
friend struct WTF::HashAndUTF8CharactersTranslator;
template<typename CharacterType> friend struct WTF::BufferFromStaticDataTranslator;
friend struct WTF::LCharBufferTranslator;
friend struct WTF::SubstringTranslator;
friend struct WTF::UCharBufferTranslator;
friend class JSC::LLInt::Data;
friend class JSC::LLIntOffsetsExtractor;
friend class AtomicStringImpl;
friend class SymbolImpl;
friend class PrivateSymbolImpl;
friend class RegisteredSymbolImpl;
private:
enum BufferOwnership {
BufferInternal,
BufferOwned,
BufferSubstring,
};
// The bottom 6 bits in the hash are flags.
public:
static constexpr const unsigned s_flagCount = 6;
private:
static constexpr const unsigned s_flagMask = (1u << s_flagCount) - 1;
static_assert(s_flagCount <= StringHasher::flagCount, "StringHasher reserves enough bits for StringImpl flags");
static constexpr const unsigned s_flagStringKindCount = 4;
static constexpr const unsigned s_hashFlagStringKindIsAtomic = 1u << (s_flagStringKindCount);
static constexpr const unsigned s_hashFlagStringKindIsSymbol = 1u << (s_flagStringKindCount + 1);
static constexpr const unsigned s_hashMaskStringKind = s_hashFlagStringKindIsAtomic | s_hashFlagStringKindIsSymbol;
static constexpr const unsigned s_hashFlag8BitBuffer = 1u << 3;
static constexpr const unsigned s_hashFlagDidReportCost = 1u << 2;
static constexpr const unsigned s_hashMaskBufferOwnership = (1u << 0) | (1u << 1);
enum StringKind {
StringNormal = 0u, // non-symbol, non-atomic
StringAtomic = s_hashFlagStringKindIsAtomic, // non-symbol, atomic
StringSymbol = s_hashFlagStringKindIsSymbol, // symbol, non-atomic
};
// FIXME: there has to be a less hacky way to do this.
enum Force8Bit { Force8BitConstructor };
// Create a normal 8-bit string with internal storage (BufferInternal)
StringImpl(unsigned length, Force8Bit)
: StringImplShape(s_refCountIncrement, length, tailPointer<LChar>(), s_hashFlag8BitBuffer | StringNormal | BufferInternal)
{
ASSERT(m_data8);
ASSERT(m_length);
STRING_STATS_ADD_8BIT_STRING(m_length);
}
// Create a normal 16-bit string with internal storage (BufferInternal)
StringImpl(unsigned length)
: StringImplShape(s_refCountIncrement, length, tailPointer<UChar>(), StringNormal | BufferInternal)
{
ASSERT(m_data16);
ASSERT(m_length);
STRING_STATS_ADD_16BIT_STRING(m_length);
}
// Create a StringImpl adopting ownership of the provided buffer (BufferOwned)
StringImpl(MallocPtr<LChar> characters, unsigned length)
: StringImplShape(s_refCountIncrement, length, characters.leakPtr(), s_hashFlag8BitBuffer | StringNormal | BufferOwned)
{
ASSERT(m_data8);
ASSERT(m_length);
STRING_STATS_ADD_8BIT_STRING(m_length);
}
enum ConstructWithoutCopyingTag { ConstructWithoutCopying };
StringImpl(const UChar* characters, unsigned length, ConstructWithoutCopyingTag)
: StringImplShape(s_refCountIncrement, length, characters, StringNormal | BufferInternal)
{
ASSERT(m_data16);
ASSERT(m_length);
STRING_STATS_ADD_16BIT_STRING(m_length);
}
StringImpl(const LChar* characters, unsigned length, ConstructWithoutCopyingTag)
: StringImplShape(s_refCountIncrement, length, characters, s_hashFlag8BitBuffer | StringNormal | BufferInternal)
{
ASSERT(m_data8);
ASSERT(m_length);
STRING_STATS_ADD_8BIT_STRING(m_length);
}
// Create a StringImpl adopting ownership of the provided buffer (BufferOwned)
StringImpl(MallocPtr<UChar> characters, unsigned length)
: StringImplShape(s_refCountIncrement, length, characters.leakPtr(), StringNormal | BufferOwned)
{
ASSERT(m_data16);
ASSERT(m_length);
STRING_STATS_ADD_16BIT_STRING(m_length);
}
// Used to create new strings that are a substring of an existing 8-bit StringImpl (BufferSubstring)
StringImpl(const LChar* characters, unsigned length, Ref<StringImpl>&& base)
: StringImplShape(s_refCountIncrement, length, characters, s_hashFlag8BitBuffer | StringNormal | BufferSubstring)
{
ASSERT(is8Bit());
ASSERT(m_data8);
ASSERT(m_length);
ASSERT(base->bufferOwnership() != BufferSubstring);
substringBuffer() = &base.leakRef();
STRING_STATS_ADD_8BIT_STRING2(m_length, true);
}
// Used to create new strings that are a substring of an existing 16-bit StringImpl (BufferSubstring)
StringImpl(const UChar* characters, unsigned length, Ref<StringImpl>&& base)
: StringImplShape(s_refCountIncrement, length, characters, StringNormal | BufferSubstring)
{
ASSERT(!is8Bit());
ASSERT(m_data16);
ASSERT(m_length);
ASSERT(base->bufferOwnership() != BufferSubstring);
substringBuffer() = &base.leakRef();
STRING_STATS_ADD_16BIT_STRING2(m_length, true);
}
public:
WTF_EXPORT_STRING_API static void destroy(StringImpl*);
WTF_EXPORT_STRING_API static Ref<StringImpl> create(const UChar*, unsigned length);
WTF_EXPORT_STRING_API static Ref<StringImpl> create(const LChar*, unsigned length);
WTF_EXPORT_STRING_API static Ref<StringImpl> create8BitIfPossible(const UChar*, unsigned length);
template<size_t inlineCapacity>
static Ref<StringImpl> create8BitIfPossible(const Vector<UChar, inlineCapacity>& vector)
{
return create8BitIfPossible(vector.data(), vector.size());
}
WTF_EXPORT_STRING_API static Ref<StringImpl> create8BitIfPossible(const UChar*);
ALWAYS_INLINE static Ref<StringImpl> create(const char* s, unsigned length) { return create(reinterpret_cast<const LChar*>(s), length); }
WTF_EXPORT_STRING_API static Ref<StringImpl> create(const LChar*);
ALWAYS_INLINE static Ref<StringImpl> create(const char* s) { return create(reinterpret_cast<const LChar*>(s)); }
static ALWAYS_INLINE Ref<StringImpl> createSubstringSharingImpl(StringImpl& rep, unsigned offset, unsigned length)
{
ASSERT(length <= rep.length());
if (!length)
return *empty();
auto* ownerRep = ((rep.bufferOwnership() == BufferSubstring) ? rep.substringBuffer() : &rep);
// We allocate a buffer that contains both the StringImpl struct as well as the pointer to the owner string.
auto* stringImpl = static_cast<StringImpl*>(fastMalloc(allocationSize<StringImpl*>(1)));
if (rep.is8Bit())
return adoptRef(*new (NotNull, stringImpl) StringImpl(rep.m_data8 + offset, length, *ownerRep));
return adoptRef(*new (NotNull, stringImpl) StringImpl(rep.m_data16 + offset, length, *ownerRep));
}
template<unsigned characterCount>
ALWAYS_INLINE static Ref<StringImpl> createFromLiteral(const char (&characters)[characterCount])
{
COMPILE_ASSERT(characterCount > 1, StringImplFromLiteralNotEmpty);
COMPILE_ASSERT((characterCount - 1 <= ((unsigned(~0) - sizeof(StringImpl)) / sizeof(LChar))), StringImplFromLiteralCannotOverflow);
return createWithoutCopying(reinterpret_cast<const LChar*>(characters), characterCount - 1);
}
// FIXME: Transition off of these functions to createWithoutCopying instead.
WTF_EXPORT_STRING_API static Ref<StringImpl> createFromLiteral(const char* characters, unsigned length);
WTF_EXPORT_STRING_API static Ref<StringImpl> createFromLiteral(const char* characters);
WTF_EXPORT_STRING_API static Ref<StringImpl> createWithoutCopying(const UChar* characters, unsigned length);
WTF_EXPORT_STRING_API static Ref<StringImpl> createWithoutCopying(const LChar* characters, unsigned length);
WTF_EXPORT_STRING_API static Ref<StringImpl> createUninitialized(unsigned length, LChar*& data);
WTF_EXPORT_STRING_API static Ref<StringImpl> createUninitialized(unsigned length, UChar*& data);
template <typename T> static ALWAYS_INLINE RefPtr<StringImpl> tryCreateUninitialized(unsigned length, T*& output)
{
if (!length) {
output = nullptr;
return empty();
}
if (length > ((std::numeric_limits<unsigned>::max() - sizeof(StringImpl)) / sizeof(T))) {
output = nullptr;
return nullptr;
}
StringImpl* resultImpl;
if (!tryFastMalloc(allocationSize<T>(length)).getValue(resultImpl)) {
output = nullptr;
return nullptr;
}
output = resultImpl->tailPointer<T>();
return constructInternal<T>(resultImpl, length);
}
// Reallocate the StringImpl. The originalString must be only owned by the Ref,
// and the buffer ownership must be BufferInternal. Just like the input pointer of realloc(),
// the originalString can't be used after this function.
static Ref<StringImpl> reallocate(Ref<StringImpl>&& originalString, unsigned length, LChar*& data);
static Ref<StringImpl> reallocate(Ref<StringImpl>&& originalString, unsigned length, UChar*& data);
static unsigned flagsOffset() { return OBJECT_OFFSETOF(StringImpl, m_hashAndFlags); }
static unsigned flagIs8Bit() { return s_hashFlag8BitBuffer; }
static unsigned flagIsAtomic() { return s_hashFlagStringKindIsAtomic; }
static unsigned flagIsSymbol() { return s_hashFlagStringKindIsSymbol; }
static unsigned maskStringKind() { return s_hashMaskStringKind; }
static unsigned dataOffset() { return OBJECT_OFFSETOF(StringImpl, m_data8); }
template<typename CharType, size_t inlineCapacity, typename OverflowHandler>
static Ref<StringImpl> adopt(Vector<CharType, inlineCapacity, OverflowHandler>&& vector)
{
if (size_t size = vector.size()) {
ASSERT(vector.data());
if (size > std::numeric_limits<unsigned>::max())
CRASH();
return adoptRef(*new StringImpl(vector.releaseBuffer(), size));
}
return *empty();
}
WTF_EXPORT_STRING_API static Ref<StringImpl> adopt(StringBuffer<UChar>&&);
WTF_EXPORT_STRING_API static Ref<StringImpl> adopt(StringBuffer<LChar>&&);
unsigned length() const { return m_length; }
static ptrdiff_t lengthMemoryOffset() { return OBJECT_OFFSETOF(StringImpl, m_length); }
bool is8Bit() const { return m_hashAndFlags & s_hashFlag8BitBuffer; }
ALWAYS_INLINE const LChar* characters8() const { ASSERT(is8Bit()); return m_data8; }
ALWAYS_INLINE const UChar* characters16() const { ASSERT(!is8Bit()); return m_data16; }
template <typename CharType>
ALWAYS_INLINE const CharType *characters() const;
size_t cost() const
{
// For substrings, return the cost of the base string.
if (bufferOwnership() == BufferSubstring)
return substringBuffer()->cost();
// Note: we must not alter the m_hashAndFlags field in instances of StaticStringImpl.
// We ensure this by pre-setting the s_hashFlagDidReportCost bit in all instances of
// StaticStringImpl. As a result, StaticStringImpl instances will always return a cost of
// 0 here and avoid modifying m_hashAndFlags.
if (m_hashAndFlags & s_hashFlagDidReportCost)
return 0;
m_hashAndFlags |= s_hashFlagDidReportCost;
size_t result = m_length;
if (!is8Bit())
result <<= 1;
return result;
}
size_t costDuringGC()
{
if (isStatic())
return 0;
if (bufferOwnership() == BufferSubstring)
return divideRoundedUp(substringBuffer()->costDuringGC(), refCount());
size_t result = m_length;
if (!is8Bit())
result <<= 1;
return divideRoundedUp(result, refCount());
}
WTF_EXPORT_STRING_API size_t sizeInBytes() const;
StringKind stringKind() const { return static_cast<StringKind>(m_hashAndFlags & s_hashMaskStringKind); }
bool isSymbol() const { return m_hashAndFlags & s_hashFlagStringKindIsSymbol; }
bool isAtomic() const { return m_hashAndFlags & s_hashFlagStringKindIsAtomic; }
void setIsAtomic(bool isAtomic)
{
ASSERT(!isStatic());
ASSERT(!isSymbol());
if (isAtomic) {
m_hashAndFlags |= s_hashFlagStringKindIsAtomic;
ASSERT(stringKind() == StringAtomic);
} else {
m_hashAndFlags &= ~s_hashFlagStringKindIsAtomic;
ASSERT(stringKind() == StringNormal);
}
}
#if STRING_STATS
bool isSubString() const { return bufferOwnership() == BufferSubstring; }
#endif
static WTF_EXPORT_STRING_API CString utf8ForCharacters(const LChar* characters, unsigned length);
static WTF_EXPORT_STRING_API CString utf8ForCharacters(const UChar* characters, unsigned length, ConversionMode = LenientConversion);
WTF_EXPORT_STRING_API CString utf8ForRange(unsigned offset, unsigned length, ConversionMode = LenientConversion) const;
WTF_EXPORT_STRING_API CString utf8(ConversionMode = LenientConversion) const;
private:
static WTF_EXPORT_STRING_API bool utf8Impl(const UChar* characters, unsigned length, char*& buffer, size_t bufferSize, ConversionMode);
// The high bits of 'hash' are always empty, but we prefer to store our flags
// in the low bits because it makes them slightly more efficient to access.
// So, we shift left and right when setting and getting our hash code.
void setHash(unsigned hash) const
{
ASSERT(!hasHash());
ASSERT(!isStatic());
// Multiple clients assume that StringHasher is the canonical string hash function.
ASSERT(hash == (is8Bit() ? StringHasher::computeHashAndMaskTop8Bits(m_data8, m_length) : StringHasher::computeHashAndMaskTop8Bits(m_data16, m_length)));
ASSERT(!(hash & (s_flagMask << (8 * sizeof(hash) - s_flagCount)))); // Verify that enough high bits are empty.
hash <<= s_flagCount;
ASSERT(!(hash & m_hashAndFlags)); // Verify that enough low bits are empty after shift.
ASSERT(hash); // Verify that 0 is a valid sentinel hash value.
m_hashAndFlags |= hash; // Store hash with flags in low bits.
}
unsigned rawHash() const
{
return m_hashAndFlags >> s_flagCount;
}
public:
bool hasHash() const
{
return rawHash() != 0;
}
unsigned existingHash() const
{
ASSERT(hasHash());
return rawHash();
}
unsigned hash() const
{
if (hasHash())
return existingHash();
return hashSlowCase();
}
WTF_EXPORT_PRIVATE unsigned concurrentHash() const;
unsigned symbolAwareHash() const;
unsigned existingSymbolAwareHash() const;
bool isStatic() const { return m_refCount & s_refCountFlagIsStaticString; }
inline size_t refCount() const
{
return m_refCount / s_refCountIncrement;
}
inline bool hasOneRef() const
{
return m_refCount == s_refCountIncrement;
}
// This method is useful for assertions.
inline bool hasAtLeastOneRef() const
{
return !!m_refCount;
}
inline void ref()
{
STRING_STATS_REF_STRING(*this);
m_refCount += s_refCountIncrement;
}
inline void deref()
{
STRING_STATS_DEREF_STRING(*this);
unsigned tempRefCount = m_refCount - s_refCountIncrement;
if (!tempRefCount) {
StringImpl::destroy(this);
return;
}
m_refCount = tempRefCount;
}
class StaticStringImpl : private StringImplShape {
WTF_MAKE_NONCOPYABLE(StaticStringImpl);
public:
// Used to construct static strings, which have an special refCount that can never hit zero.
// This means that the static string will never be destroyed, which is important because
// static strings will be shared across threads & ref-counted in a non-threadsafe manner.
//
// In order to make StaticStringImpl thread safe, we also need to ensure that the rest of
// the fields are never mutated by threads. We have this guarantee because:
//
// 1. m_length is only set on construction and never mutated thereafter.
//
// 2. m_data8 and m_data16 are only set on construction and never mutated thereafter.
// We also know that a StringImpl never changes from 8 bit to 16 bit because there
// is no way to set/clear the s_hashFlag8BitBuffer flag other than at construction.
//
// 3. m_hashAndFlags will not be mutated by different threads because:
//
// a. StaticStringImpl's constructor sets the s_hashFlagDidReportCost flag to ensure
// that StringImpl::cost() returns early.
// This means StaticStringImpl costs are not counted. But since there should only
// be a finite set of StaticStringImpls, their cost can be aggregated into a single
// system cost if needed.
// b. setIsAtomic() is never called on a StaticStringImpl.
// setIsAtomic() asserts !isStatic().
// c. setHash() is never called on a StaticStringImpl.
// StaticStringImpl's constructor sets the hash on construction.
// StringImpl::hash() only sets a new hash iff !hasHash().
// Additionally, StringImpl::setHash() asserts hasHash() and !isStatic().
template<unsigned characterCount>
constexpr StaticStringImpl(const char (&characters)[characterCount], StringKind stringKind = StringNormal)
: StringImplShape(s_refCountFlagIsStaticString, characterCount - 1, characters,
s_hashFlag8BitBuffer | s_hashFlagDidReportCost | stringKind | BufferInternal | (StringHasher::computeLiteralHashAndMaskTop8Bits(characters) << s_flagCount), ConstructWithConstExpr)
{
}
template<unsigned characterCount>
constexpr StaticStringImpl(const char16_t (&characters)[characterCount], StringKind stringKind = StringNormal)
: StringImplShape(s_refCountFlagIsStaticString, characterCount - 1, characters,
s_hashFlagDidReportCost | stringKind | BufferInternal | (StringHasher::computeLiteralHashAndMaskTop8Bits(characters) << s_flagCount), ConstructWithConstExpr)
{
}
operator StringImpl&()
{
return *reinterpret_cast<StringImpl*>(this);
}
};
WTF_EXPORTDATA static StaticStringImpl s_atomicEmptyString;
ALWAYS_INLINE static StringImpl* empty() { return reinterpret_cast<StringImpl*>(&s_atomicEmptyString); }
// FIXME: Does this really belong in StringImpl?
template <typename T> static void copyChars(T* destination, const T* source, unsigned numCharacters)
{
if (numCharacters == 1) {
*destination = *source;
return;
}
memcpy(destination, source, numCharacters * sizeof(T));
}
ALWAYS_INLINE static void copyChars(UChar* destination, const LChar* source, unsigned numCharacters)
{
for (unsigned i = 0; i < numCharacters; ++i)
destination[i] = source[i];
}
// Some string features, like refcounting and the atomicity flag, are not
// thread-safe. We achieve thread safety by isolation, giving each thread
// its own copy of the string.
Ref<StringImpl> isolatedCopy() const;
WTF_EXPORT_STRING_API Ref<StringImpl> substring(unsigned pos, unsigned len = UINT_MAX);
UChar at(unsigned i) const
{
ASSERT_WITH_SECURITY_IMPLICATION(i < m_length);
if (is8Bit())
return m_data8[i];
return m_data16[i];
}
UChar operator[](unsigned i) const { return at(i); }
WTF_EXPORT_STRING_API UChar32 characterStartingAt(unsigned);
WTF_EXPORT_STRING_API bool containsOnlyWhitespace();
int toIntStrict(bool* ok = 0, int base = 10);
unsigned toUIntStrict(bool* ok = 0, int base = 10);
int64_t toInt64Strict(bool* ok = 0, int base = 10);
uint64_t toUInt64Strict(bool* ok = 0, int base = 10);
intptr_t toIntPtrStrict(bool* ok = 0, int base = 10);
WTF_EXPORT_STRING_API int toInt(bool* ok = 0); // ignores trailing garbage
unsigned toUInt(bool* ok = 0); // ignores trailing garbage
int64_t toInt64(bool* ok = 0); // ignores trailing garbage
uint64_t toUInt64(bool* ok = 0); // ignores trailing garbage
intptr_t toIntPtr(bool* ok = 0); // ignores trailing garbage
// FIXME: Like the strict functions above, these give false for "ok" when there is trailing garbage.
// Like the non-strict functions above, these return the value when there is trailing garbage.
// It would be better if these were more consistent with the above functions instead.
double toDouble(bool* ok = 0);
float toFloat(bool* ok = 0);
WTF_EXPORT_STRING_API Ref<StringImpl> convertToASCIILowercase();
WTF_EXPORT_STRING_API Ref<StringImpl> convertToASCIIUppercase();
WTF_EXPORT_STRING_API Ref<StringImpl> convertToLowercaseWithoutLocale();
WTF_EXPORT_STRING_API Ref<StringImpl> convertToLowercaseWithoutLocaleStartingAtFailingIndex8Bit(unsigned);
WTF_EXPORT_STRING_API Ref<StringImpl> convertToUppercaseWithoutLocale();
WTF_EXPORT_STRING_API Ref<StringImpl> convertToLowercaseWithLocale(const AtomicString& localeIdentifier);
WTF_EXPORT_STRING_API Ref<StringImpl> convertToUppercaseWithLocale(const AtomicString& localeIdentifier);
Ref<StringImpl> foldCase();
Ref<StringImpl> stripWhiteSpace();
Ref<StringImpl> stripWhiteSpace(IsWhiteSpaceFunctionPtr);
WTF_EXPORT_STRING_API Ref<StringImpl> simplifyWhiteSpace();
Ref<StringImpl> simplifyWhiteSpace(IsWhiteSpaceFunctionPtr);
Ref<StringImpl> removeCharacters(CharacterMatchFunctionPtr);
template <typename CharType>
ALWAYS_INLINE Ref<StringImpl> removeCharacters(const CharType* characters, CharacterMatchFunctionPtr);
size_t find(LChar character, unsigned start = 0);
size_t find(char character, unsigned start = 0);
size_t find(UChar character, unsigned start = 0);
WTF_EXPORT_STRING_API size_t find(CharacterMatchFunctionPtr, unsigned index = 0);
size_t find(const LChar*, unsigned index = 0);
ALWAYS_INLINE size_t find(const char* s, unsigned index = 0) { return find(reinterpret_cast<const LChar*>(s), index); }
WTF_EXPORT_STRING_API size_t find(StringImpl*);
WTF_EXPORT_STRING_API size_t find(StringImpl*, unsigned index);
size_t findIgnoringCase(const LChar*, unsigned index = 0);
ALWAYS_INLINE size_t findIgnoringCase(const char* s, unsigned index = 0) { return findIgnoringCase(reinterpret_cast<const LChar*>(s), index); }
WTF_EXPORT_STRING_API size_t findIgnoringCase(StringImpl*, unsigned index = 0);
WTF_EXPORT_STRING_API size_t findIgnoringASCIICase(const StringImpl&) const;
WTF_EXPORT_STRING_API size_t findIgnoringASCIICase(const StringImpl&, unsigned startOffset) const;
WTF_EXPORT_STRING_API size_t findIgnoringASCIICase(const StringImpl*) const;
WTF_EXPORT_STRING_API size_t findIgnoringASCIICase(const StringImpl*, unsigned startOffset) const;
WTF_EXPORT_STRING_API size_t reverseFind(UChar, unsigned index = UINT_MAX);
WTF_EXPORT_STRING_API size_t reverseFind(StringImpl*, unsigned index = UINT_MAX);
WTF_EXPORT_STRING_API size_t reverseFindIgnoringCase(StringImpl*, unsigned index = UINT_MAX);
WTF_EXPORT_STRING_API bool startsWith(const StringImpl*) const;
WTF_EXPORT_STRING_API bool startsWith(const StringImpl&) const;
WTF_EXPORT_STRING_API bool startsWithIgnoringASCIICase(const StringImpl*) const;
WTF_EXPORT_STRING_API bool startsWithIgnoringASCIICase(const StringImpl&) const;
bool startsWith(StringImpl* str, bool caseSensitive) { return caseSensitive ? startsWith(str) : (reverseFindIgnoringCase(str, 0) == 0); }
WTF_EXPORT_STRING_API bool startsWith(UChar) const;
WTF_EXPORT_STRING_API bool startsWith(const char*, unsigned matchLength, bool caseSensitive) const;
template<unsigned matchLength>
bool startsWith(const char (&prefix)[matchLength], bool caseSensitive = true) const { return startsWith(prefix, matchLength - 1, caseSensitive); }
WTF_EXPORT_STRING_API bool hasInfixStartingAt(const StringImpl&, unsigned startOffset) const;
WTF_EXPORT_STRING_API bool endsWith(StringImpl*);
WTF_EXPORT_STRING_API bool endsWith(StringImpl&);
WTF_EXPORT_STRING_API bool endsWithIgnoringASCIICase(const StringImpl*) const;
WTF_EXPORT_STRING_API bool endsWithIgnoringASCIICase(const StringImpl&) const;
WTF_EXPORT_STRING_API bool endsWith(StringImpl*, bool caseSensitive);
WTF_EXPORT_STRING_API bool endsWith(UChar) const;
WTF_EXPORT_STRING_API bool endsWith(const char*, unsigned matchLength, bool caseSensitive) const;
template<unsigned matchLength>
bool endsWith(const char (&prefix)[matchLength], bool caseSensitive = true) const { return endsWith(prefix, matchLength - 1, caseSensitive); }
WTF_EXPORT_STRING_API bool hasInfixEndingAt(const StringImpl&, unsigned endOffset) const;
WTF_EXPORT_STRING_API Ref<StringImpl> replace(UChar, UChar);
WTF_EXPORT_STRING_API Ref<StringImpl> replace(UChar, StringImpl*);
ALWAYS_INLINE Ref<StringImpl> replace(UChar pattern, const char* replacement, unsigned replacementLength) { return replace(pattern, reinterpret_cast<const LChar*>(replacement), replacementLength); }
WTF_EXPORT_STRING_API Ref<StringImpl> replace(UChar, const LChar*, unsigned replacementLength);
Ref<StringImpl> replace(UChar, const UChar*, unsigned replacementLength);
WTF_EXPORT_STRING_API Ref<StringImpl> replace(StringImpl*, StringImpl*);
WTF_EXPORT_STRING_API Ref<StringImpl> replace(unsigned index, unsigned len, StringImpl*);
WTF_EXPORT_STRING_API UCharDirection defaultWritingDirection(bool* hasStrongDirectionality = nullptr);
#if USE(CF)
RetainPtr<CFStringRef> createCFString();
#endif
#ifdef __OBJC__
WTF_EXPORT_STRING_API operator NSString *();
#endif
#if STRING_STATS
ALWAYS_INLINE static StringStats& stringStats() { return m_stringStats; }
#endif
protected:
~StringImpl();
enum CreateSymbolTag { CreateSymbol };
// Used to create new symbol strings that holds existing 8-bit [[Description]] string as a substring buffer (BufferSubstring).
StringImpl(CreateSymbolTag, const LChar* characters, unsigned length)
: StringImplShape(s_refCountIncrement, length, characters, s_hashFlag8BitBuffer | StringSymbol | BufferSubstring)
{
ASSERT(is8Bit());
ASSERT(m_data8);
STRING_STATS_ADD_8BIT_STRING2(m_length, true);
}
// Used to create new symbol strings that holds existing 16-bit [[Description]] string as a substring buffer (BufferSubstring).
StringImpl(CreateSymbolTag, const UChar* characters, unsigned length)
: StringImplShape(s_refCountIncrement, length, characters, StringSymbol | BufferSubstring)
{
ASSERT(!is8Bit());
ASSERT(m_data16);
STRING_STATS_ADD_16BIT_STRING2(m_length, true);
}
// Null symbol.
StringImpl(CreateSymbolTag)
: StringImplShape(s_refCountIncrement, 0, empty()->characters8(), s_hashFlag8BitBuffer | StringSymbol | BufferSubstring)
{
ASSERT(is8Bit());
ASSERT(m_data8);
STRING_STATS_ADD_8BIT_STRING2(m_length, true);
}
template<typename T>
static size_t allocationSize(Checked<size_t> tailElementCount)
{
return (tailOffset<T>() + tailElementCount * sizeof(T)).unsafeGet();
}
template<typename T>
static size_t tailOffset()
{
#if COMPILER(MSVC)
// MSVC doesn't support alignof yet.
return roundUpToMultipleOf<sizeof(T)>(sizeof(StringImpl));
#else
return roundUpToMultipleOf<alignof(T)>(offsetof(StringImpl, m_hashAndFlags) + sizeof(StringImpl::m_hashAndFlags));
#endif
}
private:
bool requiresCopy() const
{
if (bufferOwnership() != BufferInternal)
return true;
if (is8Bit())
return m_data8 == tailPointer<LChar>();
return m_data16 == tailPointer<UChar>();
}
template<typename T>
const T* tailPointer() const
{
return reinterpret_cast_ptr<const T*>(reinterpret_cast<const uint8_t*>(this) + tailOffset<T>());
}
template<typename T>
T* tailPointer()
{
return reinterpret_cast_ptr<T*>(reinterpret_cast<uint8_t*>(this) + tailOffset<T>());
}
StringImpl* const& substringBuffer() const
{
ASSERT(bufferOwnership() == BufferSubstring);
return *tailPointer<StringImpl*>();
}
StringImpl*& substringBuffer()
{
ASSERT(bufferOwnership() == BufferSubstring);
return *tailPointer<StringImpl*>();
}
enum class CaseConvertType { Upper, Lower };
template<CaseConvertType type, typename CharacterType> static Ref<StringImpl> convertASCIICase(StringImpl&, const CharacterType*, unsigned);
BufferOwnership bufferOwnership() const { return static_cast<BufferOwnership>(m_hashAndFlags & s_hashMaskBufferOwnership); }
template <class UCharPredicate> Ref<StringImpl> stripMatchedCharacters(UCharPredicate);
template <typename CharType, class UCharPredicate> Ref<StringImpl> simplifyMatchedCharactersToSpace(UCharPredicate);
template <typename CharType> static Ref<StringImpl> constructInternal(StringImpl*, unsigned);
template <typename CharType> static Ref<StringImpl> createUninitializedInternal(unsigned, CharType*&);
template <typename CharType> static Ref<StringImpl> createUninitializedInternalNonEmpty(unsigned, CharType*&);
template <typename CharType> static Ref<StringImpl> reallocateInternal(Ref<StringImpl>&&, unsigned, CharType*&);
template <typename CharType> static Ref<StringImpl> createInternal(const CharType*, unsigned);
WTF_EXPORT_PRIVATE NEVER_INLINE unsigned hashSlowCase() const;
// The bottom bit in the ref count indicates a static (immortal) string.
static const unsigned s_refCountFlagIsStaticString = 0x1;
static const unsigned s_refCountIncrement = 0x2; // This allows us to ref / deref without disturbing the static string flag.
#if STRING_STATS
WTF_EXPORTDATA static StringStats m_stringStats;
#endif
public:
#ifndef NDEBUG
void assertHashIsCorrect()
{
ASSERT(hasHash());
ASSERT(existingHash() == StringHasher::computeHashAndMaskTop8Bits(characters8(), length()));
}
#endif
};
using StaticStringImpl = StringImpl::StaticStringImpl;
static_assert(sizeof(StringImpl) == sizeof(StaticStringImpl), "");
#if ASSERT_ENABLED
// StringImpls created from StaticStringImpl will ASSERT
// in the generic ValueCheck<T>::checkConsistency
// as they are not allocated by fastMalloc.
// We don't currently have any way to detect that case
// so we ignore the consistency check for all StringImpl*.
template<> struct
ValueCheck<StringImpl*> {
static void checkConsistency(const StringImpl*) { }
};
#endif
template <>
ALWAYS_INLINE Ref<StringImpl> StringImpl::constructInternal<LChar>(StringImpl* impl, unsigned length) { return adoptRef(*new (NotNull, impl) StringImpl(length, Force8BitConstructor)); }
template <>
ALWAYS_INLINE Ref<StringImpl> StringImpl::constructInternal<UChar>(StringImpl* impl, unsigned length) { return adoptRef(*new (NotNull, impl) StringImpl(length)); }
template <>
ALWAYS_INLINE const LChar* StringImpl::characters<LChar>() const { return characters8(); }
template <>
ALWAYS_INLINE const UChar* StringImpl::characters<UChar>() const { return characters16(); }
WTF_EXPORT_STRING_API bool equal(const StringImpl*, const StringImpl*);
WTF_EXPORT_STRING_API bool equal(const StringImpl*, const LChar*);
inline bool equal(const StringImpl* a, const char* b) { return equal(a, reinterpret_cast<const LChar*>(b)); }
WTF_EXPORT_STRING_API bool equal(const StringImpl*, const LChar*, unsigned);
WTF_EXPORT_STRING_API bool equal(const StringImpl*, const UChar*, unsigned);
inline bool equal(const StringImpl* a, const char* b, unsigned length) { return equal(a, reinterpret_cast<const LChar*>(b), length); }
inline bool equal(const LChar* a, StringImpl* b) { return equal(b, a); }
inline bool equal(const char* a, StringImpl* b) { return equal(b, reinterpret_cast<const LChar*>(a)); }
WTF_EXPORT_STRING_API bool equal(const StringImpl& a, const StringImpl& b);
WTF_EXPORT_STRING_API bool equalIgnoringNullity(StringImpl*, StringImpl*);
WTF_EXPORT_STRING_API bool equalIgnoringNullity(const UChar*, size_t length, StringImpl*);
bool equalIgnoringASCIICase(const StringImpl&, const StringImpl&);
WTF_EXPORT_STRING_API bool equalIgnoringASCIICase(const StringImpl*, const StringImpl*);
bool equalIgnoringASCIICase(const StringImpl&, const char*);
bool equalIgnoringASCIICase(const StringImpl*, const char*);
WTF_EXPORT_STRING_API bool equalIgnoringASCIICaseNonNull(const StringImpl*, const StringImpl*);
template<unsigned length> bool equalLettersIgnoringASCIICase(const StringImpl&, const char (&lowercaseLetters)[length]);
template<unsigned length> bool equalLettersIgnoringASCIICase(const StringImpl*, const char (&lowercaseLetters)[length]);
inline size_t find(const LChar* characters, unsigned length, CharacterMatchFunctionPtr matchFunction, unsigned index = 0)
{
while (index < length) {
if (matchFunction(characters[index]))
return index;
++index;
}
return notFound;
}
inline size_t find(const UChar* characters, unsigned length, CharacterMatchFunctionPtr matchFunction, unsigned index = 0)
{
while (index < length) {
if (matchFunction(characters[index]))
return index;
++index;
}
return notFound;
}
template<typename CharacterType>
inline size_t reverseFindLineTerminator(const CharacterType* characters, unsigned length, unsigned index = UINT_MAX)
{
if (!length)
return notFound;
if (index >= length)
index = length - 1;
CharacterType c = characters[index];
while ((c != '\n') && (c != '\r')) {
if (!index--)
return notFound;
c = characters[index];
}
return index;
}
template<typename CharacterType>
inline size_t reverseFind(const CharacterType* characters, unsigned length, CharacterType matchCharacter, unsigned index = UINT_MAX)
{
if (!length)
return notFound;
if (index >= length)
index = length - 1;
while (characters[index] != matchCharacter) {
if (!index--)
return notFound;
}
return index;
}
ALWAYS_INLINE size_t reverseFind(const UChar* characters, unsigned length, LChar matchCharacter, unsigned index = UINT_MAX)
{
return reverseFind(characters, length, static_cast<UChar>(matchCharacter), index);
}
inline size_t reverseFind(const LChar* characters, unsigned length, UChar matchCharacter, unsigned index = UINT_MAX)
{
if (matchCharacter & ~0xFF)
return notFound;
return reverseFind(characters, length, static_cast<LChar>(matchCharacter), index);
}
inline size_t StringImpl::find(LChar character, unsigned start)
{
if (is8Bit())
return WTF::find(characters8(), m_length, character, start);
return WTF::find(characters16(), m_length, character, start);
}
ALWAYS_INLINE size_t StringImpl::find(char character, unsigned start)
{
return find(static_cast<LChar>(character), start);
}
inline size_t StringImpl::find(UChar character, unsigned start)
{
if (is8Bit())
return WTF::find(characters8(), m_length, character, start);
return WTF::find(characters16(), m_length, character, start);
}
template<size_t inlineCapacity> inline bool equalIgnoringNullity(const Vector<UChar, inlineCapacity>& a, StringImpl* b)
{
return equalIgnoringNullity(a.data(), a.size(), b);
}
template<typename CharacterType1, typename CharacterType2>
inline int codePointCompare(unsigned l1, unsigned l2, const CharacterType1* c1, const CharacterType2* c2)
{
const unsigned lmin = l1 < l2 ? l1 : l2;
unsigned pos = 0;
while (pos < lmin && *c1 == *c2) {
++c1;
++c2;
++pos;
}
if (pos < lmin)
return (c1[0] > c2[0]) ? 1 : -1;
if (l1 == l2)
return 0;
return (l1 > l2) ? 1 : -1;
}
inline int codePointCompare8(const StringImpl* string1, const StringImpl* string2)
{
return codePointCompare(string1->length(), string2->length(), string1->characters8(), string2->characters8());
}
inline int codePointCompare16(const StringImpl* string1, const StringImpl* string2)
{
return codePointCompare(string1->length(), string2->length(), string1->characters16(), string2->characters16());
}
inline int codePointCompare8To16(const StringImpl* string1, const StringImpl* string2)
{
return codePointCompare(string1->length(), string2->length(), string1->characters8(), string2->characters16());
}
inline int codePointCompare(const StringImpl* string1, const StringImpl* string2)
{
if (!string1)
return (string2 && string2->length()) ? -1 : 0;
if (!string2)
return string1->length() ? 1 : 0;
bool string1Is8Bit = string1->is8Bit();
bool string2Is8Bit = string2->is8Bit();
if (string1Is8Bit) {
if (string2Is8Bit)
return codePointCompare8(string1, string2);
return codePointCompare8To16(string1, string2);
}
if (string2Is8Bit)
return -codePointCompare8To16(string2, string1);
return codePointCompare16(string1, string2);
}
inline bool isSpaceOrNewline(UChar32 c)
{
// Use isASCIISpace() for basic Latin-1.
// This will include newlines, which aren't included in Unicode DirWS.
return c <= 0x7F ? isASCIISpace(c) : u_charDirection(c) == U_WHITE_SPACE_NEUTRAL;
}
template<typename CharacterType>
inline unsigned lengthOfNullTerminatedString(const CharacterType* string)
{
ASSERT(string);
size_t length = 0;
while (string[length])
++length;
RELEASE_ASSERT(length < std::numeric_limits<unsigned>::max());
return static_cast<unsigned>(length);
}
inline Ref<StringImpl> StringImpl::isolatedCopy() const
{
if (!requiresCopy()) {
if (is8Bit())
return StringImpl::createWithoutCopying(m_data8, m_length);
return StringImpl::createWithoutCopying(m_data16, m_length);
}
if (is8Bit())
return create(m_data8, m_length);
return create(m_data16, m_length);
}
// StringHash is the default hash for StringImpl* and RefPtr<StringImpl>
template<typename T> struct DefaultHash;
template<> struct DefaultHash<StringImpl*> {
typedef StringHash Hash;
};
template<> struct DefaultHash<RefPtr<StringImpl>> {
typedef StringHash Hash;
};
inline bool equalIgnoringASCIICase(const StringImpl& a, const StringImpl& b)
{
return equalIgnoringASCIICaseCommon(a, b);
}
inline bool equalIgnoringASCIICase(const StringImpl& a, const char* b)
{
return equalIgnoringASCIICaseCommon(a, b);
}
inline bool equalIgnoringASCIICase(const StringImpl* a, const char* b)
{
return a && equalIgnoringASCIICase(*a, b);
}
template<unsigned length> inline bool startsWithLettersIgnoringASCIICase(const StringImpl& string, const char (&lowercaseLetters)[length])
{
return startsWithLettersIgnoringASCIICaseCommon(string, lowercaseLetters);
}
template<unsigned length> inline bool startsWithLettersIgnoringASCIICase(const StringImpl* string, const char (&lowercaseLetters)[length])
{
return string && startsWithLettersIgnoringASCIICase(*string, lowercaseLetters);
}
template<unsigned length> inline bool equalLettersIgnoringASCIICase(const StringImpl& string, const char (&lowercaseLetters)[length])
{
return equalLettersIgnoringASCIICaseCommon(string, lowercaseLetters);
}
template<unsigned length> inline bool equalLettersIgnoringASCIICase(const StringImpl* string, const char (&lowercaseLetters)[length])
{
return string && equalLettersIgnoringASCIICase(*string, lowercaseLetters);
}
#define MAKE_STATIC_STRING_IMPL(characters) ([] { \
static StaticStringImpl impl(characters); \
return &impl; \
}())
} // namespace WTF
using WTF::StringImpl;
using WTF::StaticStringImpl;
using WTF::equal;
using WTF::TextCaseSensitivity;
using WTF::TextCaseSensitive;
using WTF::TextCaseInsensitive;
#endif