gecko-dev/xpcom/string/nsTString.h
Nicholas Nethercote 2511b2c327 Bug 1267550 (part 2) - Rename MOZ_WARN_UNUSED_RESULT as MOZ_MUST_USE. r=froydnj.
It's an annotation that is used a lot, and should be used even more, so a
shorter name is better.

MozReview-Commit-ID: 1VS4Dney4WX

--HG--
extra : rebase_source : b26919c1b0fcb32e5339adeef5be5becae6032cf
2016-04-27 14:16:50 +10:00

882 lines
23 KiB
C++

/* -*- 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"
/**
* This is the canonical null-terminated string class. All subclasses
* promise null-terminated storage. Instances of this class allocate
* strings on the heap.
*
* NAMES:
* nsString for wide characters
* nsCString for narrow characters
*
* This class is also known as nsAFlat[C]String, where "flat" is used
* to denote a null-terminated string.
*/
class nsTString_CharT : public nsTSubstring_CharT
{
public:
typedef nsTString_CharT self_type;
public:
/**
* constructors
*/
nsTString_CharT()
: substring_type()
{
}
explicit
nsTString_CharT(const char_type* aData, size_type aLength = size_type(-1))
: substring_type()
{
Assign(aData, aLength);
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
explicit
nsTString_CharT(char16ptr_t aStr, size_type aLength = size_type(-1))
: substring_type()
{
Assign(static_cast<const char16_t*>(aStr), aLength);
}
#endif
nsTString_CharT(const self_type& aStr)
: substring_type()
{
Assign(aStr);
}
MOZ_IMPLICIT nsTString_CharT(const substring_tuple_type& aTuple)
: substring_type()
{
Assign(aTuple);
}
explicit
nsTString_CharT(const substring_type& aReadable)
: substring_type()
{
Assign(aReadable);
}
// |operator=| does not inherit, so we must define our own
self_type& operator=(char_type aChar)
{
Assign(aChar);
return *this;
}
self_type& operator=(const char_type* aData)
{
Assign(aData);
return *this;
}
self_type& operator=(const self_type& aStr)
{
Assign(aStr);
return *this;
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
self_type& operator=(const char16ptr_t aStr)
{
Assign(static_cast<const char16_t*>(aStr));
return *this;
}
#endif
self_type& operator=(const substring_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_tuple_type& aTuple)
{
Assign(aTuple);
return *this;
}
/**
* returns the null-terminated string
*/
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
char16ptr_t get() const
#else
const char_type* get() const
#endif
{
return mData;
}
/**
* returns character at specified index.
*
* NOTE: unlike nsTSubstring::CharAt, this function allows you to index
* the null terminator character.
*/
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);
}
#if MOZ_STRING_WITH_OBSOLETE_API
/**
* Search for the given substring within this string.
*
* @param aString is substring to be sought in this
* @param aIgnoreCase selects case sensitivity
* @param aOffset tells us where in this string to start searching
* @param aCount tells us how far from the offset we are to search. Use
* -1 to search the whole string.
* @return offset in string, or kNotFound
*/
int32_t Find(const nsCString& aString, bool aIgnoreCase = false,
int32_t aOffset = 0, int32_t aCount = -1) const;
int32_t Find(const char* aString, bool aIgnoreCase = false,
int32_t aOffset = 0, int32_t aCount = -1) const;
#ifdef CharT_is_PRUnichar
int32_t Find(const nsAFlatString& aString, int32_t aOffset = 0,
int32_t aCount = -1) const;
int32_t Find(const char16_t* aString, int32_t aOffset = 0,
int32_t aCount = -1) const;
#ifdef MOZ_USE_CHAR16_WRAPPER
int32_t Find(char16ptr_t aString, int32_t aOffset = 0,
int32_t aCount = -1) const
{
return Find(static_cast<const char16_t*>(aString), aOffset, aCount);
}
#endif
#endif
/**
* This methods scans the string backwards, looking for the given string
*
* @param aString is substring to be sought in this
* @param aIgnoreCase tells us whether or not to do caseless compare
* @param aOffset tells us where in this string to start searching.
* Use -1 to search from the end of the string.
* @param aCount tells us how many iterations to make starting at the
* given offset.
* @return offset in string, or kNotFound
*/
int32_t RFind(const nsCString& aString, bool aIgnoreCase = false,
int32_t aOffset = -1, int32_t aCount = -1) const;
int32_t RFind(const char* aCString, bool aIgnoreCase = false,
int32_t aOffset = -1, int32_t aCount = -1) const;
#ifdef CharT_is_PRUnichar
int32_t RFind(const nsAFlatString& aString, int32_t aOffset = -1,
int32_t aCount = -1) const;
int32_t RFind(const char16_t* aString, int32_t aOffset = -1,
int32_t aCount = -1) const;
#endif
/**
* Search for given char within this string
*
* @param aChar is the character to search for
* @param aOffset tells us where in this string to start searching
* @param aCount tells us how far from the offset we are to search.
* Use -1 to search the whole string.
* @return offset in string, or kNotFound
*/
// int32_t FindChar( char16_t aChar, int32_t aOffset=0, int32_t aCount=-1 ) const;
int32_t RFindChar(char16_t aChar, int32_t aOffset = -1,
int32_t aCount = -1) const;
/**
* This method searches this string for the first character found in
* the given string.
*
* @param aString contains set of chars to be found
* @param aOffset tells us where in this string to start searching
* (counting from left)
* @return offset in string, or kNotFound
*/
int32_t FindCharInSet(const char* aString, int32_t aOffset = 0) const;
int32_t FindCharInSet(const self_type& aString, int32_t aOffset = 0) const
{
return FindCharInSet(aString.get(), aOffset);
}
#ifdef CharT_is_PRUnichar
int32_t FindCharInSet(const char16_t* aString, int32_t aOffset = 0) const;
#endif
/**
* This method searches this string for the last character found in
* the given string.
*
* @param aString contains set of chars to be found
* @param aOffset tells us where in this string to start searching
* (counting from left)
* @return offset in string, or kNotFound
*/
int32_t RFindCharInSet(const char_type* aString, int32_t aOffset = -1) const;
int32_t RFindCharInSet(const self_type& aString, int32_t aOffset = -1) const
{
return RFindCharInSet(aString.get(), aOffset);
}
/**
* Compares a given string to this string.
*
* @param aString is the string to be compared
* @param aIgnoreCase tells us how to treat case
* @param aCount tells us how many chars to compare
* @return -1,0,1
*/
#ifdef CharT_is_char
int32_t Compare(const char* aString, bool aIgnoreCase = false,
int32_t aCount = -1) const;
#endif
/**
* Equality check between given string and this string.
*
* @param aString is the string to check
* @param aIgnoreCase tells us how to treat case
* @param aCount tells us how many chars to compare
* @return boolean
*/
#ifdef CharT_is_char
bool EqualsIgnoreCase(const char* aString, int32_t aCount = -1) const
{
return Compare(aString, true, aCount) == 0;
}
#else
bool EqualsIgnoreCase(const char* aString, int32_t aCount = -1) const;
#endif // !CharT_is_PRUnichar
/**
* Perform string to double-precision float conversion.
*
* @param aErrorCode will contain error if one occurs
* @return double-precision float rep of string value
*/
double ToDouble(nsresult* aErrorCode) const;
/**
* Perform string to single-precision float conversion.
*
* @param aErrorCode will contain error if one occurs
* @return single-precision float rep of string value
*/
float ToFloat(nsresult* aErrorCode) const
{
return (float)ToDouble(aErrorCode);
}
/**
* Perform string to int conversion.
* @param aErrorCode will contain error if one occurs
* @param aRadix tells us which radix to assume; kAutoDetect tells us to determine the radix for you.
* @return int rep of string value, and possible (out) error code
*/
int32_t ToInteger(nsresult* aErrorCode, uint32_t aRadix = kRadix10) const;
/**
* Perform string to 64-bit int conversion.
* @param aErrorCode will contain error if one occurs
* @param aRadix tells us which radix to assume; kAutoDetect tells us to determine the radix for you.
* @return 64-bit int rep of string value, and possible (out) error code
*/
int64_t ToInteger64(nsresult* aErrorCode, uint32_t aRadix = kRadix10) const;
/**
* |Left|, |Mid|, and |Right| are annoying signatures that seem better almost
* any _other_ way than they are now. Consider these alternatives
*
* aWritable = aReadable.Left(17); // ...a member function that returns a |Substring|
* aWritable = Left(aReadable, 17); // ...a global function that returns a |Substring|
* Left(aReadable, 17, aWritable); // ...a global function that does the assignment
*
* as opposed to the current signature
*
* aReadable.Left(aWritable, 17); // ...a member function that does the assignment
*
* or maybe just stamping them out in favor of |Substring|, they are just duplicate functionality
*
* aWritable = Substring(aReadable, 0, 17);
*/
size_type Mid(self_type& aResult, uint32_t aStartPos, uint32_t aCount) const;
size_type Left(self_type& aResult, size_type aCount) const
{
return Mid(aResult, 0, aCount);
}
size_type Right(self_type& aResult, size_type aCount) const
{
aCount = XPCOM_MIN(mLength, aCount);
return Mid(aResult, mLength - aCount, aCount);
}
/**
* Set a char inside this string at given index
*
* @param aChar is the char you want to write into this string
* @param anIndex is the ofs where you want to write the given char
* @return TRUE if successful
*/
bool SetCharAt(char16_t aChar, uint32_t aIndex);
/**
* These methods are used to remove all occurrences of the
* characters found in aSet from this string.
*
* @param aSet -- characters to be cut from this
*/
void StripChars(const char* aSet);
/**
* This method strips whitespace throughout the string.
*/
void StripWhitespace();
/**
* swaps occurence of 1 string for another
*/
void ReplaceChar(char_type aOldChar, char_type aNewChar);
void ReplaceChar(const char* aSet, char_type aNewChar);
#ifdef CharT_is_PRUnichar
void ReplaceChar(const char16_t* aSet, char16_t aNewChar);
#endif
/**
* Replace all occurrences of aTarget with aNewValue.
* The complexity of this function is O(n+m), n being the length of the string
* and m being the length of aNewValue.
*/
void ReplaceSubstring(const self_type& aTarget, const self_type& aNewValue);
void ReplaceSubstring(const char_type* aTarget, const char_type* aNewValue);
MOZ_MUST_USE bool ReplaceSubstring(const self_type& aTarget,
const self_type& aNewValue,
const fallible_t&);
MOZ_MUST_USE bool ReplaceSubstring(const char_type* aTarget,
const char_type* aNewValue,
const fallible_t&);
/**
* This method trims characters found in aTrimSet from
* either end of the underlying string.
*
* @param aSet -- contains chars to be trimmed from both ends
* @param aEliminateLeading
* @param aEliminateTrailing
* @param aIgnoreQuotes -- if true, causes surrounding quotes to be ignored
* @return this
*/
void Trim(const char* aSet, bool aEliminateLeading = true,
bool aEliminateTrailing = true, bool aIgnoreQuotes = false);
/**
* This method strips whitespace from string.
* You can control whether whitespace is yanked from start and end of
* string as well.
*
* @param aEliminateLeading controls stripping of leading ws
* @param aEliminateTrailing controls stripping of trailing ws
*/
void CompressWhitespace(bool aEliminateLeading = true,
bool aEliminateTrailing = true);
/**
* assign/append/insert with _LOSSY_ conversion
*/
void AssignWithConversion(const nsTAString_IncompatibleCharT& aString);
void AssignWithConversion(const incompatible_char_type* aData,
int32_t aLength = -1);
#endif // !MOZ_STRING_WITH_OBSOLETE_API
/**
* Allow this string to be bound to a character buffer
* until the string is rebound or mutated; the caller
* must ensure that the buffer outlives the string.
*/
void Rebind(const char_type* aData, size_type aLength);
/**
* verify restrictions for dependent strings
*/
void AssertValidDependentString()
{
NS_ASSERTION(mData, "nsTDependentString must wrap a non-NULL buffer");
NS_ASSERTION(mLength != size_type(-1), "nsTDependentString has bogus length");
NS_ASSERTION(mData[mLength] == 0,
"nsTDependentString must wrap only null-terminated strings. "
"You are probably looking for nsTDependentSubstring.");
}
protected:
explicit
nsTString_CharT(uint32_t aFlags)
: substring_type(aFlags)
{
}
// allow subclasses to initialize fields directly
nsTString_CharT(char_type* aData, size_type aLength, uint32_t aFlags)
: substring_type(aData, aLength, aFlags)
{
}
struct Segment {
uint32_t mBegin, mLength;
Segment(uint32_t aBegin, uint32_t aLength)
: mBegin(aBegin)
, mLength(aLength)
{}
};
};
class nsTFixedString_CharT : public nsTString_CharT
{
public:
typedef nsTFixedString_CharT self_type;
typedef nsTFixedString_CharT fixed_string_type;
public:
/**
* @param aData
* fixed-size buffer to be used by the string (the contents of
* this buffer may be modified by the string)
* @param aStorageSize
* the size of the fixed buffer
* @param aLength (optional)
* the length of the string already contained in the buffer
*/
nsTFixedString_CharT(char_type* aData, size_type aStorageSize)
: string_type(aData, uint32_t(char_traits::length(aData)),
F_TERMINATED | F_FIXED | F_CLASS_FIXED)
, mFixedCapacity(aStorageSize - 1)
, mFixedBuf(aData)
{
}
nsTFixedString_CharT(char_type* aData, size_type aStorageSize,
size_type aLength)
: string_type(aData, aLength, F_TERMINATED | F_FIXED | F_CLASS_FIXED)
, mFixedCapacity(aStorageSize - 1)
, mFixedBuf(aData)
{
// null-terminate
mFixedBuf[aLength] = char_type(0);
}
// |operator=| does not inherit, so we must define our own
self_type& operator=(char_type aChar)
{
Assign(aChar);
return *this;
}
self_type& operator=(const char_type* aData)
{
Assign(aData);
return *this;
}
self_type& operator=(const substring_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_tuple_type& aTuple)
{
Assign(aTuple);
return *this;
}
protected:
friend class nsTSubstring_CharT;
size_type mFixedCapacity;
char_type* mFixedBuf;
};
/**
* nsTAutoString_CharT
*
* Subclass of nsTString_CharT that adds support for stack-based string
* allocation. It is normally not a good idea to use this class on the
* heap, because it will allocate space which may be wasted if the string
* it contains is significantly smaller or any larger than 64 characters.
*
* NAMES:
* nsAutoString for wide characters
* nsAutoCString for narrow characters
*/
class MOZ_NON_MEMMOVABLE nsTAutoString_CharT : public nsTFixedString_CharT
{
public:
typedef nsTAutoString_CharT self_type;
public:
/**
* constructors
*/
nsTAutoString_CharT()
: fixed_string_type(mStorage, kDefaultStorageSize, 0)
{
}
explicit
nsTAutoString_CharT(char_type aChar)
: fixed_string_type(mStorage, kDefaultStorageSize, 0)
{
Assign(aChar);
}
explicit
nsTAutoString_CharT(const char_type* aData, size_type aLength = size_type(-1))
: fixed_string_type(mStorage, kDefaultStorageSize, 0)
{
Assign(aData, aLength);
}
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
explicit
nsTAutoString_CharT(char16ptr_t aData, size_type aLength = size_type(-1))
: nsTAutoString_CharT(static_cast<const char16_t*>(aData), aLength)
{
}
#endif
nsTAutoString_CharT(const self_type& aStr)
: fixed_string_type(mStorage, kDefaultStorageSize, 0)
{
Assign(aStr);
}
explicit
nsTAutoString_CharT(const substring_type& aStr)
: fixed_string_type(mStorage, kDefaultStorageSize, 0)
{
Assign(aStr);
}
MOZ_IMPLICIT nsTAutoString_CharT(const substring_tuple_type& aTuple)
: fixed_string_type(mStorage, kDefaultStorageSize, 0)
{
Assign(aTuple);
}
// |operator=| does not inherit, so we must define our own
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 aStr)
{
Assign(aStr);
return *this;
}
#endif
self_type& operator=(const self_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_tuple_type& aTuple)
{
Assign(aTuple);
return *this;
}
enum
{
kDefaultStorageSize = 64
};
private:
char_type mStorage[kDefaultStorageSize];
};
//
// nsAutoString stores pointers into itself which are invalidated when an
// nsTArray is resized, so nsTArray must not be instantiated with nsAutoString
// elements!
//
template<class E> class nsTArrayElementTraits;
template<>
class nsTArrayElementTraits<nsTAutoString_CharT>
{
public:
template<class A> struct Dont_Instantiate_nsTArray_of;
template<class A> struct Instead_Use_nsTArray_of;
static Dont_Instantiate_nsTArray_of<nsTAutoString_CharT>*
Construct(Instead_Use_nsTArray_of<nsTString_CharT>* aE)
{
return 0;
}
template<class A>
static Dont_Instantiate_nsTArray_of<nsTAutoString_CharT>*
Construct(Instead_Use_nsTArray_of<nsTString_CharT>* aE, const A& aArg)
{
return 0;
}
static Dont_Instantiate_nsTArray_of<nsTAutoString_CharT>*
Destruct(Instead_Use_nsTArray_of<nsTString_CharT>* aE)
{
return 0;
}
};
/**
* nsTXPIDLString extends nsTString such that:
*
* (1) mData can be null
* (2) objects of this type can be automatically cast to |const CharT*|
* (3) getter_Copies method is supported to adopt data allocated with
* moz_xmalloc, such as "out string" parameters in XPIDL.
*
* NAMES:
* nsXPIDLString for wide characters
* nsXPIDLCString for narrow characters
*/
class nsTXPIDLString_CharT : public nsTString_CharT
{
public:
typedef nsTXPIDLString_CharT self_type;
public:
nsTXPIDLString_CharT()
: string_type(char_traits::sEmptyBuffer, 0, F_TERMINATED | F_VOIDED)
{
}
// copy-constructor required to avoid default
nsTXPIDLString_CharT(const self_type& aStr)
: string_type(char_traits::sEmptyBuffer, 0, F_TERMINATED | F_VOIDED)
{
Assign(aStr);
}
// return nullptr if we are voided
#if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
char16ptr_t get() const
#else
const char_type* get() const
#endif
{
return (mFlags & F_VOIDED) ? nullptr : mData;
}
// this case operator is the reason why this class cannot just be a
// typedef for nsTString
operator const char_type*() const
{
return get();
}
// need this to diambiguous operator[int]
char_type operator[](int32_t aIndex) const
{
return CharAt(index_type(aIndex));
}
// |operator=| does not inherit, so we must define our own
self_type& operator=(char_type aChar)
{
Assign(aChar);
return *this;
}
self_type& operator=(const char_type* aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const self_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_tuple_type& aTuple)
{
Assign(aTuple);
return *this;
}
};
/**
* getter_Copies support for use with raw string out params:
*
* NS_IMETHOD GetBlah(char**);
*
* void some_function()
* {
* nsXPIDLCString blah;
* GetBlah(getter_Copies(blah));
* // ...
* }
*/
class MOZ_STACK_CLASS nsTGetterCopies_CharT
{
public:
typedef CharT char_type;
explicit nsTGetterCopies_CharT(nsTSubstring_CharT& aStr)
: mString(aStr)
, mData(nullptr)
{
}
~nsTGetterCopies_CharT()
{
mString.Adopt(mData); // OK if mData is null
}
operator char_type**()
{
return &mData;
}
private:
nsTSubstring_CharT& mString;
char_type* mData;
};
inline nsTGetterCopies_CharT
getter_Copies(nsTSubstring_CharT& aString)
{
return nsTGetterCopies_CharT(aString);
}
/**
* nsTAdoptingString extends nsTXPIDLString such that:
*
* (1) Adopt given string on construction or assignment, i.e. take
* the value of what's given, and make what's given forget its
* value. Note that this class violates constness in a few
* places. Be careful!
*/
class nsTAdoptingString_CharT : public nsTXPIDLString_CharT
{
public:
typedef nsTAdoptingString_CharT self_type;
public:
explicit nsTAdoptingString_CharT()
{
}
explicit nsTAdoptingString_CharT(char_type* aStr,
size_type aLength = size_type(-1))
{
Adopt(aStr, aLength);
}
// copy-constructor required to adopt on copy. Note that this
// will violate the constness of |aStr| in the operator=()
// call. |aStr| will be truncated as a side-effect of this
// constructor.
nsTAdoptingString_CharT(const self_type& aStr)
{
*this = aStr;
}
// |operator=| does not inherit, so we must define our own
self_type& operator=(const substring_type& aStr)
{
Assign(aStr);
return *this;
}
self_type& operator=(const substring_tuple_type& aTuple)
{
Assign(aTuple);
return *this;
}
// Adopt(), if possible, when assigning to a self_type&. Note
// that this violates the constness of aStr, aStr is always
// truncated when this operator is called.
self_type& operator=(const self_type& aStr);
private:
self_type& operator=(const char_type* aData) = delete;
self_type& operator=(char_type* aData) = delete;
};