diff -r 000000000000 -r 6474c204b198 xpcom/string/public/nsTSubstring.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/xpcom/string/public/nsTSubstring.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,956 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim:set ts=2 sw=2 sts=2 et cindent: */ +/* 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_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 const_iterator; + typedef nsWritingIterator 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& iter ) const + { + iter.mStart = mData; + iter.mEnd = mData + mLength; + iter.mPosition = iter.mStart; + return iter; + } + + const_iterator& EndReading( const_iterator& iter ) const + { + iter.mStart = mData; + iter.mEnd = mData + mLength; + iter.mPosition = iter.mEnd; + return iter; + } + + const_char_iterator& BeginReading( const_char_iterator& iter ) const + { + return iter = mData; + } + + const_char_iterator& EndReading( const_char_iterator& iter ) const + { + return iter = 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& iter ) + { + return iter = BeginWriting(); + } + + char_iterator& BeginWriting( char_iterator& iter, const fallible_t& ) + { + return iter = BeginWriting(fallible_t()); + } + + char_iterator& EndWriting( char_iterator& iter ) + { + return iter = EndWriting(); + } + + char_iterator& EndWriting( char_iterator& iter, const fallible_t& ) + { + return iter = EndWriting(fallible_t()); + } + + /** + * deprecated writing iterators + */ + + iterator& BeginWriting( iterator& iter ) + { + char_type *data = BeginWriting(); + iter.mStart = data; + iter.mEnd = data + mLength; + iter.mPosition = iter.mStart; + return iter; + } + + iterator& EndWriting( iterator& iter ) + { + char_type *data = BeginWriting(); + iter.mStart = data; + iter.mEnd = data + mLength; + iter.mPosition = iter.mEnd; + return iter; + } + + /** + * 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 i ) const + { + NS_ASSERTION(i < mLength, "index exceeds allowable range"); + return mData[i]; + } + + char_type operator[]( index_type i ) const + { + return CharAt(i); + } + + 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 offset = 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* data ) const; + bool NS_FASTCALL Equals( const char_type* data, const comparator_type& comp ) const; + +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + bool NS_FASTCALL Equals( char16ptr_t data ) const + { + return Equals(static_cast(data)); + } + bool NS_FASTCALL Equals( char16ptr_t data, const comparator_type& comp ) const + { + return Equals(static_cast(data), comp); + } +#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* data, size_type len ) 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* data ) 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 + inline bool EqualsLiteral( const char (&str)[N] ) const + { + return EqualsASCII(str, 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* data, size_type len ) const; + bool NS_FASTCALL LowerCaseEqualsASCII( const char* data ) 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 + inline bool LowerCaseEqualsLiteral( const char (&str)[N] ) const + { + return LowerCaseEqualsASCII(str, N-1); + } + + /** + * assignment + */ + + void NS_FASTCALL Assign( char_type c ); + bool NS_FASTCALL Assign( char_type c, const fallible_t& ) NS_WARN_UNUSED_RESULT; + + void NS_FASTCALL Assign( const char_type* data ); + void NS_FASTCALL Assign( const char_type* data, size_type length ); + bool NS_FASTCALL Assign( const char_type* data, size_type length, const fallible_t& ) NS_WARN_UNUSED_RESULT; + + void NS_FASTCALL Assign( const self_type& ); + bool NS_FASTCALL Assign( const self_type&, const fallible_t& ) NS_WARN_UNUSED_RESULT; + + void NS_FASTCALL Assign( const substring_tuple_type& ); + bool NS_FASTCALL Assign( const substring_tuple_type&, const fallible_t& ) NS_WARN_UNUSED_RESULT; + +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + void Assign (char16ptr_t data) + { + Assign(static_cast(data)); + } + + bool Assign(char16ptr_t data, const fallible_t&) NS_WARN_UNUSED_RESULT + { + return Assign(static_cast(data), fallible_t()); + } + + void Assign (char16ptr_t data, size_type length) + { + Assign(static_cast(data), length); + } + + bool Assign(char16ptr_t data, size_type length, const fallible_t&) NS_WARN_UNUSED_RESULT + { + return Assign(static_cast(data), length, fallible_t()); + } +#endif + + void NS_FASTCALL AssignASCII( const char* data, size_type length ); + bool NS_FASTCALL AssignASCII( const char* data, size_type length, const fallible_t& ) NS_WARN_UNUSED_RESULT; + + void NS_FASTCALL AssignASCII( const char* data ) + { + AssignASCII(data, mozilla::SafeCast(strlen(data))); + } + bool NS_FASTCALL AssignASCII( const char* data, const fallible_t& ) NS_WARN_UNUSED_RESULT + { + return AssignASCII(data, mozilla::SafeCast(strlen(data)), 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 + void AssignLiteral( const char_type (&str)[N] ) + { AssignLiteral(str, N - 1); } +#ifdef CharT_is_PRUnichar + template + void AssignLiteral( const char (&str)[N] ) + { AssignASCII(str, N-1); } +#endif + + self_type& operator=( char_type c ) { Assign(c); return *this; } + self_type& operator=( const char_type* data ) { Assign(data); return *this; } +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + self_type& operator=( char16ptr_t data ) { Assign(data); return *this; } +#endif + self_type& operator=( const self_type& str ) { Assign(str); return *this; } + self_type& operator=( const substring_tuple_type& tuple ) { Assign(tuple); return *this; } + + void NS_FASTCALL Adopt( char_type* data, size_type length = size_type(-1) ); + + + /** + * buffer manipulation + */ + + void NS_FASTCALL Replace( index_type cutStart, size_type cutLength, char_type c ); + bool NS_FASTCALL Replace( index_type cutStart, size_type cutLength, char_type c, const mozilla::fallible_t&) NS_WARN_UNUSED_RESULT; + void NS_FASTCALL Replace( index_type cutStart, size_type cutLength, const char_type* data, size_type length = size_type(-1) ); + bool NS_FASTCALL Replace( index_type cutStart, size_type cutLength, const char_type* data, size_type length, const mozilla::fallible_t&) NS_WARN_UNUSED_RESULT; + void Replace( index_type cutStart, size_type cutLength, const self_type& str ) { Replace(cutStart, cutLength, str.Data(), str.Length()); } + bool Replace( index_type cutStart, size_type cutLength, const self_type& str, const mozilla::fallible_t&) NS_WARN_UNUSED_RESULT + { return Replace(cutStart, cutLength, str.Data(), str.Length(), mozilla::fallible_t()); } + void NS_FASTCALL Replace( index_type cutStart, size_type cutLength, const substring_tuple_type& tuple ); + + void NS_FASTCALL ReplaceASCII( index_type cutStart, size_type cutLength, const char* data, size_type length = 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 + void ReplaceLiteral( index_type cutStart, size_type cutLength, const char_type (&str)[N] ) { ReplaceLiteral(cutStart, cutLength, str, N - 1); } + + void Append( char_type c ) { Replace(mLength, 0, c); } + bool Append( char_type c, const mozilla::fallible_t&) NS_WARN_UNUSED_RESULT { return Replace(mLength, 0, c, mozilla::fallible_t()); } + void Append( const char_type* data, size_type length = size_type(-1) ) { Replace(mLength, 0, data, length); } + bool Append( const char_type* data, size_type length, const mozilla::fallible_t&) NS_WARN_UNUSED_RESULT + { return Replace(mLength, 0, data, length, mozilla::fallible_t()); } + +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + void Append( char16ptr_t data, size_type length = size_type(-1) ) { Append(static_cast(data), length); } +#endif + + void Append( const self_type& str ) { Replace(mLength, 0, str); } + void Append( const substring_tuple_type& tuple ) { Replace(mLength, 0, tuple); } + + void AppendASCII( const char* data, size_type length = size_type(-1) ) { ReplaceASCII(mLength, 0, data, length); } + + /** + * Append a formatted string to the current string. Uses the format + * codes documented in prprf.h + */ + void AppendPrintf( const char* format, ... ); + void AppendPrintf( const char* format, va_list ap ); + 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 + void AppendLiteral( const char_type (&str)[N] ) { ReplaceLiteral(mLength, 0, str, N - 1); } +#ifdef CharT_is_PRUnichar + template + void AppendLiteral( const char (&str)[N] ) + { AppendASCII(str, N-1); } +#endif + + self_type& operator+=( char_type c ) { Append(c); return *this; } + self_type& operator+=( const char_type* data ) { Append(data); return *this; } +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + self_type& operator+=( char16ptr_t data ) { Append(data); return *this; } +#endif + self_type& operator+=( const self_type& str ) { Append(str); return *this; } + self_type& operator+=( const substring_tuple_type& tuple ) { Append(tuple); return *this; } + + void Insert( char_type c, index_type pos ) { Replace(pos, 0, c); } + void Insert( const char_type* data, index_type pos, size_type length = size_type(-1) ) { Replace(pos, 0, data, length); } +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + void Insert( char16ptr_t data, index_type pos, size_type length = size_type(-1) ) + { Insert(static_cast(data), pos, length); } +#endif + void Insert( const self_type& str, index_type pos ) { Replace(pos, 0, str); } + void Insert( const substring_tuple_type& tuple, index_type pos ) { Replace(pos, 0, tuple); } + + // 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 + void InsertLiteral( const char_type (&str)[N], index_type pos ) { ReplaceLiteral(pos, 0, str, N - 1); } + + void Cut( index_type cutStart, size_type cutLength ) { Replace(cutStart, cutLength, 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 newCapacity ); + bool NS_FASTCALL SetCapacity( size_type newCapacity, const fallible_t& ) NS_WARN_UNUSED_RESULT; + + void NS_FASTCALL SetLength( size_type newLength ); + bool NS_FASTCALL SetLength( size_type newLength, const fallible_t& ) NS_WARN_UNUSED_RESULT; + + void Truncate( size_type newLength = 0 ) + { + NS_ASSERTION(newLength <= mLength, "Truncate cannot make string longer"); + SetLength(newLength); + } + + + /** + * 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** data ) const + { + *data = 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** data, size_type newLen = size_type(-1) ) + { + if (!EnsureMutable(newLen)) + NS_ABORT_OOM(newLen == size_type(-1) ? mLength : newLen); + + *data = mData; + return mLength; + } + + size_type GetMutableData( char_type** data, size_type newLen, const fallible_t& ) + { + if (!EnsureMutable(newLen)) + { + *data = nullptr; + return 0; + } + + *data = mData; + return mLength; + } + +#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER) + size_type GetMutableData( wchar_t** data, size_type newLen = size_type(-1) ) + { + return GetMutableData(reinterpret_cast(data), newLen); + } + + size_type GetMutableData( wchar_t** data, size_type newLen, const fallible_t& ) + { + return GetMutableData(reinterpret_cast(data), newLen, 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. + */ + nsTSubstring_CharT(const substring_tuple_type& tuple) + : mData(nullptr), + mLength(0), + mFlags(F_NONE) + { + Assign(tuple); + } + + /** + * 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 *data, size_type length, uint32_t flags ); +#else +#undef XPCOM_STRING_CONSTRUCTOR_OUT_OF_LINE + nsTSubstring_CharT( char_type *data, size_type length, uint32_t flags ) + : mData(data), + mLength(length), + mFlags(flags) {} +#endif /* DEBUG || FORCE_BUILD_REFCNT_LOGGING */ + + size_t SizeOfExcludingThisMustBeUnshared(mozilla::MallocSizeOf mallocSizeOf) + const; + size_t SizeOfIncludingThisMustBeUnshared(mozilla::MallocSizeOf mallocSizeOf) + const; + + size_t SizeOfExcludingThisIfUnshared(mozilla::MallocSizeOf mallocSizeOf) + const; + size_t SizeOfIncludingThisIfUnshared(mozilla::MallocSizeOf mallocSizeOf) + 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 mallocSizeOf) + const; + size_t SizeOfIncludingThisEvenIfShared(mozilla::MallocSizeOf mallocSizeOf) + 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 flags ) + : mFlags(flags) {} + + // copy-constructor, constructs as dependent on given object + // (NOTE: this is for internal use only) + nsTSubstring_CharT( const self_type& str ) + : mData(str.mData), + mLength(str.mLength), + mFlags(str.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 capacity specifies the required capacity of mData + * @param old_data returns null or the old value of mData + * @param old_flags 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 capacity, char_type** old_data, uint32_t* old_flags ); + + /** + * 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 cutStart specifies the starting offset of the section + * @param cutLength specifies the length of the section to be replaced + * @param newLength 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. + */ + bool ReplacePrep(index_type cutStart, size_type cutLength, + size_type newLength) NS_WARN_UNUSED_RESULT + { + cutLength = XPCOM_MIN(cutLength, mLength - cutStart); + uint32_t newTotalLen = mLength - cutLength + newLength; + if (cutStart == mLength && Capacity() > newTotalLen) { + mFlags &= ~F_VOIDED; + mData[newTotalLen] = char_type(0); + mLength = newTotalLen; + return true; + } + return ReplacePrepInternal(cutStart, cutLength, newLength, newTotalLen); + } + + bool NS_FASTCALL ReplacePrepInternal(index_type cutStart, + size_type cutLength, + size_type newFragLength, + size_type newTotalLength) + NS_WARN_UNUSED_RESULT; + + /** + * 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. + */ + bool NS_FASTCALL EnsureMutable( size_type newLen = size_type(-1) ) NS_WARN_UNUSED_RESULT; + + /** + * returns true if this string overlaps with the given string fragment. + */ + bool IsDependentOn( const char_type *start, const char_type *end ) 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.end || f2.end <= f1.begin) + * + * Simplified, that gives us: + */ + return ( start < (mData + mLength) && end > mData ); + } + + /** + * this helper function stores the specified dataFlags in mFlags + */ + void SetDataFlags(uint32_t dataFlags) + { + NS_ASSERTION((dataFlags & 0xFFFF0000) == 0, "bad flags"); + mFlags = dataFlags | (mFlags & 0xFFFF0000); + } + + void NS_FASTCALL ReplaceLiteral( index_type cutStart, size_type cutLength, const char_type* data, size_type length ); + + static int AppendFunc( void* arg, const char* s, uint32_t len); + + 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* data, size_type length ); + + // 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& lhs, const nsTSubstring_CharT::base_string_type& rhs, const nsTStringComparator_CharT& = nsTDefaultStringComparator_CharT() ); + + +inline +bool operator!=( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::base_string_type& rhs ) + { + return !lhs.Equals(rhs); + } + +inline +bool operator< ( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::base_string_type& rhs ) + { + return Compare(lhs, rhs)< 0; + } + +inline +bool operator<=( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::base_string_type& rhs ) + { + return Compare(lhs, rhs)<=0; + } + +inline +bool operator==( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::base_string_type& rhs ) + { + return lhs.Equals(rhs); + } + +inline +bool operator==( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::char_type* rhs ) + { + return lhs.Equals(rhs); + } + + +inline +bool operator>=( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::base_string_type& rhs ) + { + return Compare(lhs, rhs)>=0; + } + +inline +bool operator> ( const nsTSubstring_CharT::base_string_type& lhs, const nsTSubstring_CharT::base_string_type& rhs ) + { + return Compare(lhs, rhs)> 0; + }