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gecko-dev/xpcom/string/nsTSubstring.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// IWYU pragma: private, include "nsString.h"
#include "mozilla/Casting.h"
#include "mozilla/MemoryReporting.h"
#ifndef MOZILLA_INTERNAL_API
#error Cannot use internal string classes without MOZILLA_INTERNAL_API defined. Use the frozen header nsStringAPI.h instead.
#endif
/**
* The base for string comparators
*/
class nsTStringComparator_CharT
{
public:
typedef CharT char_type;
nsTStringComparator_CharT()
{
}
virtual int operator()(const char_type*, const char_type*,
uint32_t, uint32_t) const = 0;
};
/**
* The default string comparator (case-sensitive comparision)
*/
class nsTDefaultStringComparator_CharT
: public nsTStringComparator_CharT
{
public:
typedef CharT char_type;
nsTDefaultStringComparator_CharT()
{
}
virtual int operator()(const char_type*, const char_type*,
uint32_t, uint32_t) const;
};
/**
* nsTSubstring is the most abstract class in the string hierarchy. It
* represents a single contiguous array of characters, which may or may not
* be null-terminated. This type is not instantiated directly. A sub-class
* is instantiated instead. For example, see nsTString.
*
* NAMES:
* nsAString for wide characters
* nsACString for narrow characters
*
* Many of the accessors on nsTSubstring are inlined as an optimization.
*/
class nsTSubstring_CharT
{
public:
typedef mozilla::fallible_t fallible_t;
typedef CharT char_type;
typedef nsCharTraits<char_type> char_traits;
typedef char_traits::incompatible_char_type incompatible_char_type;
typedef nsTSubstring_CharT self_type;
typedef self_type abstract_string_type;
typedef self_type base_string_type;
typedef self_type substring_type;
typedef nsTSubstringTuple_CharT substring_tuple_type;
typedef nsTString_CharT string_type;
typedef nsReadingIterator<char_type> const_iterator;
typedef nsWritingIterator<char_type> iterator;
typedef nsTStringComparator_CharT comparator_type;
typedef char_type* char_iterator;
typedef const char_type* const_char_iterator;
typedef uint32_t size_type;
typedef uint32_t index_type;
public:
// this acts like a virtual destructor
~nsTSubstring_CharT()
{
Finalize();
}
/**
* reading iterators
*/
const_char_iterator BeginReading() const
{
return mData;
}
const_char_iterator EndReading() const
{
return mData + mLength;
}
/**
* deprecated reading iterators
*/
const_iterator& BeginReading(const_iterator& aIter) const
{
aIter.mStart = mData;
aIter.mEnd = mData + mLength;
aIter.mPosition = aIter.mStart;
return aIter;
}
const_iterator& EndReading(const_iterator& aIter) const
{
aIter.mStart = mData;
aIter.mEnd = mData + mLength;
aIter.mPosition = aIter.mEnd;
return aIter;
}
const_char_iterator& BeginReading(const_char_iterator& aIter) const
{
return aIter = mData;
}
const_char_iterator& EndReading(const_char_iterator& aIter) const
{
return aIter = mData + mLength;
}
/**
* writing iterators
*/
char_iterator BeginWriting()
{
if (!EnsureMutable()) {
NS_ABORT_OOM(mLength);
}
return mData;
}
char_iterator BeginWriting(const fallible_t&)
{
return EnsureMutable() ? mData : char_iterator(0);
}
char_iterator EndWriting()
{
if (!EnsureMutable()) {
NS_ABORT_OOM(mLength);
}
return mData + mLength;
}
char_iterator EndWriting(const fallible_t&)
{
return EnsureMutable() ? (mData + mLength) : char_iterator(0);
}
char_iterator& BeginWriting(char_iterator& aIter)
{
return aIter = BeginWriting();
}
char_iterator& BeginWriting(char_iterator& aIter, const fallible_t&)
{
return aIter = BeginWriting(fallible_t());
}
char_iterator& EndWriting(char_iterator& aIter)
{
return aIter = EndWriting();
}
char_iterator& EndWriting(char_iterator& aIter, const fallible_t&)
{
return aIter = EndWriting(fallible_t());
}
/**
* deprecated writing iterators
*/
iterator& BeginWriting(iterator& aIter)
{
char_type* data = BeginWriting();
aIter.mStart = data;
aIter.mEnd = data + mLength;
aIter.mPosition = aIter.mStart;
return aIter;
}
iterator& EndWriting(iterator& aIter)
{
char_type* data = BeginWriting();
aIter.mStart = data;
aIter.mEnd = data + mLength;
aIter.mPosition = aIter.mEnd;
return aIter;
}
/**
* accessors
*/
// returns pointer to string data (not necessarily null-terminated)
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
char16ptr_t Data() const
#else
const char_type* Data() const
#endif
{
return mData;
}
size_type Length() const
{
return mLength;
}
uint32_t Flags() const
{
return mFlags;
}
bool IsEmpty() const
{
return mLength == 0;
}
bool IsLiteral() const
{
return (mFlags & F_LITERAL) != 0;
}
bool IsVoid() const
{
return (mFlags & F_VOIDED) != 0;
}
bool IsTerminated() const
{
return (mFlags & F_TERMINATED) != 0;
}
char_type CharAt(index_type aIndex) const
{
NS_ASSERTION(aIndex < mLength, "index exceeds allowable range");
return mData[aIndex];
}
char_type operator[](index_type aIndex) const
{
return CharAt(aIndex);
}
char_type First() const
{
NS_ASSERTION(mLength > 0, "|First()| called on an empty string");
return mData[0];
}
inline char_type Last() const
{
NS_ASSERTION(mLength > 0, "|Last()| called on an empty string");
return mData[mLength - 1];
}
size_type NS_FASTCALL CountChar(char_type) const;
int32_t NS_FASTCALL FindChar(char_type, index_type aOffset = 0) const;
/**
* equality
*/
bool NS_FASTCALL Equals(const self_type&) const;
bool NS_FASTCALL Equals(const self_type&, const comparator_type&) const;
bool NS_FASTCALL Equals(const char_type* aData) const;
bool NS_FASTCALL Equals(const char_type* aData,
const comparator_type& aComp) const;
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
bool NS_FASTCALL Equals(char16ptr_t aData) const
{
return Equals(static_cast<const char16_t*>(aData));
}
bool NS_FASTCALL Equals(char16ptr_t aData, const comparator_type& aComp) const
{
return Equals(static_cast<const char16_t*>(aData), aComp);
}
#endif
/**
* An efficient comparison with ASCII that can be used even
* for wide strings. Call this version when you know the
* length of 'data'.
*/
bool NS_FASTCALL EqualsASCII(const char* aData, size_type aLen) const;
/**
* An efficient comparison with ASCII that can be used even
* for wide strings. Call this version when 'data' is
* null-terminated.
*/
bool NS_FASTCALL EqualsASCII(const char* aData) const;
// EqualsLiteral must ONLY be applied to an actual literal string, or
// a char array *constant* declared without an explicit size.
// Do not attempt to use it with a regular char* pointer, or with a
// non-constant char array variable. Use EqualsASCII for them.
// The template trick to acquire the array length at compile time without
// using a macro is due to Corey Kosak, with much thanks.
template<int N>
inline bool EqualsLiteral(const char (&aStr)[N]) const
{
return EqualsASCII(aStr, N - 1);
}
// The LowerCaseEquals methods compare the ASCII-lowercase version of
// this string (lowercasing only ASCII uppercase characters) to some
// ASCII/Literal string. The ASCII string is *not* lowercased for
// you. If you compare to an ASCII or literal string that contains an
// uppercase character, it is guaranteed to return false. We will
// throw assertions too.
bool NS_FASTCALL LowerCaseEqualsASCII(const char* aData,
size_type aLen) const;
bool NS_FASTCALL LowerCaseEqualsASCII(const char* aData) const;
// LowerCaseEqualsLiteral must ONLY be applied to an actual
// literal string, or a char array *constant* declared without an
// explicit size. Do not attempt to use it with a regular char*
// pointer, or with a non-constant char array variable. Use
// LowerCaseEqualsASCII for them.
template<int N>
inline bool LowerCaseEqualsLiteral(const char (&aStr)[N]) const
{
return LowerCaseEqualsASCII(aStr, N - 1);
}
/**
* assignment
*/
void NS_FASTCALL Assign(char_type aChar);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL Assign(char_type aChar,
const fallible_t&);
void NS_FASTCALL Assign(const char_type* aData);
void NS_FASTCALL Assign(const char_type* aData, size_type aLength);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL Assign(const char_type* aData,
size_type aLength,
const fallible_t&);
void NS_FASTCALL Assign(const self_type&);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL Assign(const self_type&,
const fallible_t&);
void NS_FASTCALL Assign(const substring_tuple_type&);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL Assign(const substring_tuple_type&,
const fallible_t&);
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
void Assign(char16ptr_t aData)
{
Assign(static_cast<const char16_t*>(aData));
}
NS_WARN_UNUSED_RESULT bool Assign(char16ptr_t aData, const fallible_t&)
{
return Assign(static_cast<const char16_t*>(aData), fallible_t());
}
void Assign(char16ptr_t aData, size_type aLength)
{
Assign(static_cast<const char16_t*>(aData), aLength);
}
NS_WARN_UNUSED_RESULT bool Assign(char16ptr_t aData, size_type aLength,
const fallible_t&)
{
return Assign(static_cast<const char16_t*>(aData), aLength, fallible_t());
}
#endif
void NS_FASTCALL AssignASCII(const char* aData, size_type aLength);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL AssignASCII(const char* aData,
size_type aLength,
const fallible_t&);
void NS_FASTCALL AssignASCII(const char* aData)
{
AssignASCII(aData, mozilla::AssertedCast<size_type, size_t>(strlen(aData)));
}
NS_WARN_UNUSED_RESULT bool NS_FASTCALL AssignASCII(const char* aData,
const fallible_t&)
{
return AssignASCII(aData,
mozilla::AssertedCast<size_type, size_t>(strlen(aData)),
fallible_t());
}
// AssignLiteral must ONLY be applied to an actual literal string, or
// a char array *constant* declared without an explicit size.
// Do not attempt to use it with a regular char* pointer, or with a
// non-constant char array variable. Use AssignASCII for those.
// There are not fallible version of these methods because they only really
// apply to small allocations that we wouldn't want to check anyway.
template<int N>
void AssignLiteral(const char_type (&aStr)[N])
{
AssignLiteral(aStr, N - 1);
}
#ifdef CharT_is_PRUnichar
template<int N>
void AssignLiteral(const char (&aStr)[N])
{
AssignASCII(aStr, N - 1);
}
#endif
self_type& operator=(char_type aChar)
{
Assign(aChar);
return *this;
}
self_type& operator=(const char_type* aData)
{
Assign(aData);
return *this;
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
self_type& operator=(char16ptr_t aData)
{
Assign(aData);
return *this;
}
#endif
self_type& operator=(const self_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_tuple_type& aTuple)
{
Assign(aTuple);
return *this;
}
void NS_FASTCALL Adopt(char_type* aData, size_type aLength = size_type(-1));
/**
* buffer manipulation
*/
void NS_FASTCALL Replace(index_type aCutStart, size_type aCutLength,
char_type aChar);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL Replace(index_type aCutStart,
size_type aCutLength,
char_type aChar,
const mozilla::fallible_t&);
void NS_FASTCALL Replace(index_type aCutStart, size_type aCutLength,
const char_type* aData,
size_type aLength = size_type(-1));
NS_WARN_UNUSED_RESULT bool NS_FASTCALL Replace(index_type aCutStart,
size_type aCutLength,
const char_type* aData,
size_type aLength,
const mozilla::fallible_t&);
void Replace(index_type aCutStart, size_type aCutLength,
const self_type& aStr)
{
Replace(aCutStart, aCutLength, aStr.Data(), aStr.Length());
}
NS_WARN_UNUSED_RESULT bool Replace(index_type aCutStart,
size_type aCutLength,
const self_type& aStr,
const mozilla::fallible_t&)
{
return Replace(aCutStart, aCutLength, aStr.Data(), aStr.Length(),
mozilla::fallible_t());
}
void NS_FASTCALL Replace(index_type aCutStart, size_type aCutLength,
const substring_tuple_type& aTuple);
void NS_FASTCALL ReplaceASCII(index_type aCutStart, size_type aCutLength,
const char* aData,
size_type aLength = size_type(-1));
// ReplaceLiteral must ONLY be applied to an actual literal string.
// Do not attempt to use it with a regular char* pointer, or with a char
// array variable. Use Replace or ReplaceASCII for those.
template<int N>
void ReplaceLiteral(index_type aCutStart, size_type aCutLength,
const char_type (&aStr)[N])
{
ReplaceLiteral(aCutStart, aCutLength, aStr, N - 1);
}
void Append(char_type aChar)
{
Replace(mLength, 0, aChar);
}
NS_WARN_UNUSED_RESULT bool Append(char_type aChar,
const mozilla::fallible_t&)
{
return Replace(mLength, 0, aChar, mozilla::fallible_t());
}
void Append(const char_type* aData, size_type aLength = size_type(-1))
{
Replace(mLength, 0, aData, aLength);
}
NS_WARN_UNUSED_RESULT bool Append(const char_type* aData, size_type aLength,
const mozilla::fallible_t&)
{
return Replace(mLength, 0, aData, aLength, mozilla::fallible_t());
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
void Append(char16ptr_t aData, size_type aLength = size_type(-1))
{
Append(static_cast<const char16_t*>(aData), aLength);
}
#endif
void Append(const self_type& aStr)
{
Replace(mLength, 0, aStr);
}
void Append(const substring_tuple_type& aTuple)
{
Replace(mLength, 0, aTuple);
}
void AppendASCII(const char* aData, size_type aLength = size_type(-1))
{
ReplaceASCII(mLength, 0, aData, aLength);
}
/**
* Append a formatted string to the current string. Uses the format
* codes documented in prprf.h
*/
void AppendPrintf(const char* aFormat, ...);
void AppendPrintf(const char* aFormat, va_list aAp);
void AppendInt(int32_t aInteger)
{
AppendPrintf("%d", aInteger);
}
void AppendInt(int32_t aInteger, int aRadix)
{
const char* fmt = aRadix == 10 ? "%d" : aRadix == 8 ? "%o" : "%x";
AppendPrintf(fmt, aInteger);
}
void AppendInt(uint32_t aInteger)
{
AppendPrintf("%u", aInteger);
}
void AppendInt(uint32_t aInteger, int aRadix)
{
const char* fmt = aRadix == 10 ? "%u" : aRadix == 8 ? "%o" : "%x";
AppendPrintf(fmt, aInteger);
}
void AppendInt(int64_t aInteger)
{
AppendPrintf("%lld", aInteger);
}
void AppendInt(int64_t aInteger, int aRadix)
{
const char* fmt = aRadix == 10 ? "%lld" : aRadix == 8 ? "%llo" : "%llx";
AppendPrintf(fmt, aInteger);
}
void AppendInt(uint64_t aInteger)
{
AppendPrintf("%llu", aInteger);
}
void AppendInt(uint64_t aInteger, int aRadix)
{
const char* fmt = aRadix == 10 ? "%llu" : aRadix == 8 ? "%llo" : "%llx";
AppendPrintf(fmt, aInteger);
}
/**
* Append the given float to this string
*/
void NS_FASTCALL AppendFloat(float aFloat);
void NS_FASTCALL AppendFloat(double aFloat);
public:
// AppendLiteral must ONLY be applied to an actual literal string.
// Do not attempt to use it with a regular char* pointer, or with a char
// array variable. Use Append or AppendASCII for those.
template<int N>
void AppendLiteral(const char_type (&aStr)[N])
{
ReplaceLiteral(mLength, 0, aStr, N - 1);
}
#ifdef CharT_is_PRUnichar
template<int N>
void AppendLiteral(const char (&aStr)[N])
{
AppendASCII(aStr, N - 1);
}
#endif
self_type& operator+=(char_type aChar)
{
Append(aChar);
return *this;
}
self_type& operator+=(const char_type* aData)
{
Append(aData);
return *this;
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
self_type& operator+=(char16ptr_t aData)
{
Append(aData);
return *this;
}
#endif
self_type& operator+=(const self_type& aStr)
{
Append(aStr);
return *this;
}
self_type& operator+=(const substring_tuple_type& aTuple)
{
Append(aTuple);
return *this;
}
void Insert(char_type aChar, index_type aPos)
{
Replace(aPos, 0, aChar);
}
void Insert(const char_type* aData, index_type aPos,
size_type aLength = size_type(-1))
{
Replace(aPos, 0, aData, aLength);
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
void Insert(char16ptr_t aData, index_type aPos,
size_type aLength = size_type(-1))
{
Insert(static_cast<const char16_t*>(aData), aPos, aLength);
}
#endif
void Insert(const self_type& aStr, index_type aPos)
{
Replace(aPos, 0, aStr);
}
void Insert(const substring_tuple_type& aTuple, index_type aPos)
{
Replace(aPos, 0, aTuple);
}
// InsertLiteral must ONLY be applied to an actual literal string.
// Do not attempt to use it with a regular char* pointer, or with a char
// array variable. Use Insert for those.
template<int N>
void InsertLiteral(const char_type (&aStr)[N], index_type aPos)
{
ReplaceLiteral(aPos, 0, aStr, N - 1);
}
void Cut(index_type aCutStart, size_type aCutLength)
{
Replace(aCutStart, aCutLength, char_traits::sEmptyBuffer, 0);
}
/**
* buffer sizing
*/
/**
* Attempts to set the capacity to the given size in number of
* characters, without affecting the length of the string.
* There is no need to include room for the null terminator: it is
* the job of the string class.
* Also ensures that the buffer is mutable.
*/
void NS_FASTCALL SetCapacity(size_type aNewCapacity);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL SetCapacity(size_type aNewCapacity,
const fallible_t&);
void NS_FASTCALL SetLength(size_type aNewLength);
NS_WARN_UNUSED_RESULT bool NS_FASTCALL SetLength(size_type aNewLength,
const fallible_t&);
void Truncate(size_type aNewLength = 0)
{
NS_ASSERTION(aNewLength <= mLength, "Truncate cannot make string longer");
SetLength(aNewLength);
}
/**
* buffer access
*/
/**
* Get a const pointer to the string's internal buffer. The caller
* MUST NOT modify the characters at the returned address.
*
* @returns The length of the buffer in characters.
*/
inline size_type GetData(const char_type** aData) const
{
*aData = mData;
return mLength;
}
/**
* Get a pointer to the string's internal buffer, optionally resizing
* the buffer first. If size_type(-1) is passed for newLen, then the
* current length of the string is used. The caller MAY modify the
* characters at the returned address (up to but not exceeding the
* length of the string).
*
* @returns The length of the buffer in characters or 0 if unable to
* satisfy the request due to low-memory conditions.
*/
size_type GetMutableData(char_type** aData, size_type aNewLen = size_type(-1))
{
if (!EnsureMutable(aNewLen)) {
NS_ABORT_OOM(aNewLen == size_type(-1) ? mLength : aNewLen);
}
*aData = mData;
return mLength;
}
size_type GetMutableData(char_type** aData, size_type aNewLen, const fallible_t&)
{
if (!EnsureMutable(aNewLen)) {
*aData = nullptr;
return 0;
}
*aData = mData;
return mLength;
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
size_type GetMutableData(wchar_t** aData, size_type aNewLen = size_type(-1))
{
return GetMutableData(reinterpret_cast<char16_t**>(aData), aNewLen);
}
size_type GetMutableData(wchar_t** aData, size_type aNewLen, const fallible_t&)
{
return GetMutableData(reinterpret_cast<char16_t**>(aData), aNewLen,
fallible_t());
}
#endif
/**
* string data is never null, but can be marked void. if true, the
* string will be truncated. @see nsTSubstring::IsVoid
*/
void NS_FASTCALL SetIsVoid(bool);
/**
* This method is used to remove all occurrences of aChar from this
* string.
*
* @param aChar -- char to be stripped
* @param aOffset -- where in this string to start stripping chars
*/
void StripChar(char_type aChar, int32_t aOffset = 0);
/**
* This method is used to remove all occurrences of aChars from this
* string.
*
* @param aChars -- chars to be stripped
* @param aOffset -- where in this string to start stripping chars
*/
void StripChars(const char_type* aChars, uint32_t aOffset = 0);
/**
* If the string uses a shared buffer, this method
* clears the pointer without releasing the buffer.
*/
void ForgetSharedBuffer()
{
if (mFlags & nsSubstring::F_SHARED) {
mData = char_traits::sEmptyBuffer;
mLength = 0;
mFlags = F_TERMINATED;
}
}
public:
/**
* this is public to support automatic conversion of tuple to string
* base type, which helps avoid converting to nsTAString.
*/
MOZ_IMPLICIT nsTSubstring_CharT(const substring_tuple_type& aTuple)
: mData(nullptr)
, mLength(0)
, mFlags(F_NONE)
{
Assign(aTuple);
}
/**
* allows for direct initialization of a nsTSubstring object.
*
* NOTE: this constructor is declared public _only_ for convenience
* inside the string implementation.
*/
// XXXbz or can I just include nscore.h and use NS_BUILD_REFCNT_LOGGING?
#if defined(DEBUG) || defined(FORCE_BUILD_REFCNT_LOGGING)
#define XPCOM_STRING_CONSTRUCTOR_OUT_OF_LINE
nsTSubstring_CharT(char_type* aData, size_type aLength, uint32_t aFlags);
#else
#undef XPCOM_STRING_CONSTRUCTOR_OUT_OF_LINE
nsTSubstring_CharT(char_type* aData, size_type aLength, uint32_t aFlags)
: mData(aData)
, mLength(aLength)
, mFlags(aFlags)
{
}
#endif /* DEBUG || FORCE_BUILD_REFCNT_LOGGING */
size_t SizeOfExcludingThisMustBeUnshared(mozilla::MallocSizeOf aMallocSizeOf)
const;
size_t SizeOfIncludingThisMustBeUnshared(mozilla::MallocSizeOf aMallocSizeOf)
const;
size_t SizeOfExcludingThisIfUnshared(mozilla::MallocSizeOf aMallocSizeOf)
const;
size_t SizeOfIncludingThisIfUnshared(mozilla::MallocSizeOf aMallocSizeOf)
const;
/**
* WARNING: Only use these functions if you really know what you are
* doing, because they can easily lead to double-counting strings. If
* you do use them, please explain clearly in a comment why it's safe
* and won't lead to double-counting.
*/
size_t SizeOfExcludingThisEvenIfShared(mozilla::MallocSizeOf aMallocSizeOf)
const;
size_t SizeOfIncludingThisEvenIfShared(mozilla::MallocSizeOf aMallocSizeOf)
const;
protected:
friend class nsTObsoleteAStringThunk_CharT;
friend class nsTSubstringTuple_CharT;
// XXX GCC 3.4 needs this :-(
friend class nsTPromiseFlatString_CharT;
char_type* mData;
size_type mLength;
uint32_t mFlags;
// default initialization
nsTSubstring_CharT()
: mData(char_traits::sEmptyBuffer)
, mLength(0)
, mFlags(F_TERMINATED)
{
}
// version of constructor that leaves mData and mLength uninitialized
explicit
nsTSubstring_CharT(uint32_t aFlags)
: mFlags(aFlags)
{
}
// copy-constructor, constructs as dependent on given object
// (NOTE: this is for internal use only)
nsTSubstring_CharT(const self_type& aStr)
: mData(aStr.mData)
, mLength(aStr.mLength)
, mFlags(aStr.mFlags & (F_TERMINATED | F_VOIDED))
{
}
/**
* this function releases mData and does not change the value of
* any of its member variables. in other words, this function acts
* like a destructor.
*/
void NS_FASTCALL Finalize();
/**
* this function prepares mData to be mutated.
*
* @param aCapacity specifies the required capacity of mData
* @param aOldData returns null or the old value of mData
* @param aOldFlags returns 0 or the old value of mFlags
*
* if mData is already mutable and of sufficient capacity, then this
* function will return immediately. otherwise, it will either resize
* mData or allocate a new shared buffer. if it needs to allocate a
* new buffer, then it will return the old buffer and the corresponding
* flags. this allows the caller to decide when to free the old data.
*
* this function returns false if is unable to allocate sufficient
* memory.
*
* XXX we should expose a way for subclasses to free old_data.
*/
bool NS_FASTCALL MutatePrep(size_type aCapacity,
char_type** aOldData, uint32_t* aOldFlags);
/**
* this function prepares a section of mData to be modified. if
* necessary, this function will reallocate mData and possibly move
* existing data to open up the specified section.
*
* @param aCutStart specifies the starting offset of the section
* @param aCutLength specifies the length of the section to be replaced
* @param aNewLength specifies the length of the new section
*
* for example, suppose mData contains the string "abcdef" then
*
* ReplacePrep(2, 3, 4);
*
* would cause mData to look like "ab____f" where the characters
* indicated by '_' have an unspecified value and can be freely
* modified. this function will null-terminate mData upon return.
*
* this function returns false if is unable to allocate sufficient
* memory.
*/
NS_WARN_UNUSED_RESULT bool ReplacePrep(index_type aCutStart,
size_type aCutLength,
size_type aNewLength)
{
aCutLength = XPCOM_MIN(aCutLength, mLength - aCutStart);
uint32_t newTotalLen = mLength - aCutLength + aNewLength;
if (aCutStart == mLength && Capacity() > newTotalLen) {
mFlags &= ~F_VOIDED;
mData[newTotalLen] = char_type(0);
mLength = newTotalLen;
return true;
}
return ReplacePrepInternal(aCutStart, aCutLength, aNewLength, newTotalLen);
}
NS_WARN_UNUSED_RESULT bool NS_FASTCALL ReplacePrepInternal(
index_type aCutStart,
size_type aCutLength,
size_type aNewFragLength,
size_type aNewTotalLength);
/**
* returns the number of writable storage units starting at mData.
* the value does not include space for the null-terminator character.
*
* NOTE: this function returns 0 if mData is immutable (or the buffer
* is 0-sized).
*/
size_type NS_FASTCALL Capacity() const;
/**
* this helper function can be called prior to directly manipulating
* the contents of mData. see, for example, BeginWriting.
*/
NS_WARN_UNUSED_RESULT bool NS_FASTCALL EnsureMutable(
size_type aNewLen = size_type(-1));
/**
* returns true if this string overlaps with the given string fragment.
*/
bool IsDependentOn(const char_type* aStart, const char_type* aEnd) const
{
/**
* if it _isn't_ the case that one fragment starts after the other ends,
* or ends before the other starts, then, they conflict:
*
* !(f2.begin >= f1.aEnd || f2.aEnd <= f1.begin)
*
* Simplified, that gives us:
*/
return (aStart < (mData + mLength) && aEnd > mData);
}
/**
* this helper function stores the specified dataFlags in mFlags
*/
void SetDataFlags(uint32_t aDataFlags)
{
NS_ASSERTION((aDataFlags & 0xFFFF0000) == 0, "bad flags");
mFlags = aDataFlags | (mFlags & 0xFFFF0000);
}
void NS_FASTCALL ReplaceLiteral(index_type aCutStart, size_type aCutLength,
const char_type* aData, size_type aLength);
static int AppendFunc(void* aArg, const char* aStr, uint32_t aLen);
public:
// NOTE: this method is declared public _only_ for convenience for
// callers who don't have access to the original nsLiteralString_CharT.
void NS_FASTCALL AssignLiteral(const char_type* aData, size_type aLength);
// mFlags is a bitwise combination of the following flags. the meaning
// and interpretation of these flags is an implementation detail.
//
// NOTE: these flags are declared public _only_ for convenience inside
// the string implementation.
enum
{
F_NONE = 0, // no flags
// data flags are in the lower 16-bits
F_TERMINATED = 1 << 0, // IsTerminated returns true
F_VOIDED = 1 << 1, // IsVoid returns true
F_SHARED = 1 << 2, // mData points to a heap-allocated, shared buffer
F_OWNED = 1 << 3, // mData points to a heap-allocated, raw buffer
F_FIXED = 1 << 4, // mData points to a fixed-size writable, dependent buffer
F_LITERAL = 1 << 5, // mData points to a string literal; F_TERMINATED will also be set
// class flags are in the upper 16-bits
F_CLASS_FIXED = 1 << 16 // indicates that |this| is of type nsTFixedString
};
//
// Some terminology:
//
// "dependent buffer" A dependent buffer is one that the string class
// does not own. The string class relies on some
// external code to ensure the lifetime of the
// dependent buffer.
//
// "shared buffer" A shared buffer is one that the string class
// allocates. When it allocates a shared string
// buffer, it allocates some additional space at
// the beginning of the buffer for additional
// fields, including a reference count and a
// buffer length. See nsStringHeader.
//
// "adopted buffer" An adopted buffer is a raw string buffer
// allocated on the heap (using nsMemory::Alloc)
// of which the string class subsumes ownership.
//
// Some comments about the string flags:
//
// F_SHARED, F_OWNED, and F_FIXED are all mutually exlusive. They
// indicate the allocation type of mData. If none of these flags
// are set, then the string buffer is dependent.
//
// F_SHARED, F_OWNED, or F_FIXED imply F_TERMINATED. This is because
// the string classes always allocate null-terminated buffers, and
// non-terminated substrings are always dependent.
//
// F_VOIDED implies F_TERMINATED, and moreover it implies that mData
// points to char_traits::sEmptyBuffer. Therefore, F_VOIDED is
// mutually exclusive with F_SHARED, F_OWNED, and F_FIXED.
//
};
int NS_FASTCALL
Compare(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs,
const nsTStringComparator_CharT& = nsTDefaultStringComparator_CharT());
inline bool
operator!=(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs)
{
return !aLhs.Equals(aRhs);
}
inline bool
operator<(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs)
{
return Compare(aLhs, aRhs) < 0;
}
inline bool
operator<=(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs)
{
return Compare(aLhs, aRhs) <= 0;
}
inline bool
operator==(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs)
{
return aLhs.Equals(aRhs);
}
inline bool
operator==(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::char_type* aRhs)
{
return aLhs.Equals(aRhs);
}
inline bool
operator>=(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs)
{
return Compare(aLhs, aRhs) >= 0;
}
inline bool
operator>(const nsTSubstring_CharT::base_string_type& aLhs,
const nsTSubstring_CharT::base_string_type& aRhs)
{
return Compare(aLhs, aRhs) > 0;
}
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