gecko-dev/xpcom/string/nsReadableUtils.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

429 lines
16 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"
#ifndef nsReadableUtils_h___
#define nsReadableUtils_h___
/**
* I guess all the routines in this file are all mis-named.
* According to our conventions, they should be |NS_xxx|.
*/
#include "mozilla/Assertions.h"
#include "nsAString.h"
#include "nsTArrayForwardDeclare.h"
inline size_t
Distance(const nsReadingIterator<char16_t>& aStart,
const nsReadingIterator<char16_t>& aEnd)
{
MOZ_ASSERT(aStart.get() <= aEnd.get());
return static_cast<size_t>(aEnd.get() - aStart.get());
}
inline size_t
Distance(const nsReadingIterator<char>& aStart,
const nsReadingIterator<char>& aEnd)
{
MOZ_ASSERT(aStart.get() <= aEnd.get());
return static_cast<size_t>(aEnd.get() - aStart.get());
}
void LossyCopyUTF16toASCII(const nsAString& aSource, nsACString& aDest);
void CopyASCIItoUTF16(const nsACString& aSource, nsAString& aDest);
void LossyCopyUTF16toASCII(const char16ptr_t aSource, nsACString& aDest);
void CopyASCIItoUTF16(const char* aSource, nsAString& aDest);
void CopyUTF16toUTF8(const nsAString& aSource, nsACString& aDest);
MOZ_MUST_USE bool CopyUTF16toUTF8(const nsAString& aSource, nsACString& aDest,
const mozilla::fallible_t&);
void CopyUTF8toUTF16(const nsACString& aSource, nsAString& aDest);
void CopyUTF16toUTF8(const char16ptr_t aSource, nsACString& aDest);
void CopyUTF8toUTF16(const char* aSource, nsAString& aDest);
void LossyAppendUTF16toASCII(const nsAString& aSource, nsACString& aDest);
void AppendASCIItoUTF16(const nsACString& aSource, nsAString& aDest);
MOZ_MUST_USE bool AppendASCIItoUTF16(const nsACString& aSource,
nsAString& aDest,
const mozilla::fallible_t&);
void LossyAppendUTF16toASCII(const char16ptr_t aSource, nsACString& aDest);
MOZ_MUST_USE bool AppendASCIItoUTF16(const char* aSource,
nsAString& aDest,
const mozilla::fallible_t&);
void AppendASCIItoUTF16(const char* aSource, nsAString& aDest);
void AppendUTF16toUTF8(const nsAString& aSource, nsACString& aDest);
MOZ_MUST_USE bool AppendUTF16toUTF8(const nsAString& aSource,
nsACString& aDest,
const mozilla::fallible_t&);
void AppendUTF8toUTF16(const nsACString& aSource, nsAString& aDest);
MOZ_MUST_USE bool AppendUTF8toUTF16(const nsACString& aSource,
nsAString& aDest,
const mozilla::fallible_t&);
void AppendUTF16toUTF8(const char16ptr_t aSource, nsACString& aDest);
void AppendUTF8toUTF16(const char* aSource, nsAString& aDest);
/**
* Returns a new |char| buffer containing a zero-terminated copy of |aSource|.
*
* Allocates and returns a new |char| buffer which you must free with |free|.
* Performs a lossy encoding conversion by chopping 16-bit wide characters down to 8-bits wide while copying |aSource| to your new buffer.
* This conversion is not well defined; but it reproduces legacy string behavior.
* The new buffer is zero-terminated, but that may not help you if |aSource| contains embedded nulls.
*
* @param aSource a 16-bit wide string
* @return a new |char| buffer you must free with |free|.
*/
char* ToNewCString(const nsAString& aSource);
/**
* Returns a new |char| buffer containing a zero-terminated copy of |aSource|.
*
* Allocates and returns a new |char| buffer which you must free with |free|.
* The new buffer is zero-terminated, but that may not help you if |aSource| contains embedded nulls.
*
* @param aSource an 8-bit wide string
* @return a new |char| buffer you must free with |free|.
*/
char* ToNewCString(const nsACString& aSource);
/**
* Returns a new |char| buffer containing a zero-terminated copy of |aSource|.
*
* Allocates and returns a new |char| buffer which you must free with
* |free|.
* Performs an encoding conversion from a UTF-16 string to a UTF-8 string
* copying |aSource| to your new buffer.
* The new buffer is zero-terminated, but that may not help you if |aSource|
* contains embedded nulls.
*
* @param aSource a UTF-16 string (made of char16_t's)
* @param aUTF8Count the number of 8-bit units that was returned
* @return a new |char| buffer you must free with |free|.
*/
char* ToNewUTF8String(const nsAString& aSource, uint32_t* aUTF8Count = nullptr);
/**
* Returns a new |char16_t| buffer containing a zero-terminated copy of
* |aSource|.
*
* Allocates and returns a new |char16_t| buffer which you must free with
* |free|.
* The new buffer is zero-terminated, but that may not help you if |aSource|
* contains embedded nulls.
*
* @param aSource a UTF-16 string
* @return a new |char16_t| buffer you must free with |free|.
*/
char16_t* ToNewUnicode(const nsAString& aSource);
/**
* Returns a new |char16_t| buffer containing a zero-terminated copy of |aSource|.
*
* Allocates and returns a new |char16_t| buffer which you must free with |free|.
* Performs an encoding conversion by 0-padding 8-bit wide characters up to 16-bits wide while copying |aSource| to your new buffer.
* This conversion is not well defined; but it reproduces legacy string behavior.
* The new buffer is zero-terminated, but that may not help you if |aSource| contains embedded nulls.
*
* @param aSource an 8-bit wide string (a C-string, NOT UTF-8)
* @return a new |char16_t| buffer you must free with |free|.
*/
char16_t* ToNewUnicode(const nsACString& aSource);
/**
* Returns the required length for a char16_t buffer holding
* a copy of aSource, using UTF-8 to UTF-16 conversion.
* The length does NOT include any space for zero-termination.
*
* @param aSource an 8-bit wide string, UTF-8 encoded
* @return length of UTF-16 encoded string copy, not zero-terminated
*/
uint32_t CalcUTF8ToUnicodeLength(const nsACString& aSource);
/**
* Copies the source string into the specified buffer, converting UTF-8 to
* UTF-16 in the process. The conversion is well defined for valid UTF-8
* strings.
* The copied string will be zero-terminated! Any embedded nulls will be
* copied nonetheless. It is the caller's responsiblity to ensure the buffer
* is large enough to hold the string copy plus one char16_t for
* zero-termination!
*
* @see CalcUTF8ToUnicodeLength( const nsACString& )
* @see UTF8ToNewUnicode( const nsACString&, uint32_t* )
*
* @param aSource an 8-bit wide string, UTF-8 encoded
* @param aBuffer the buffer holding the converted string copy
* @param aUTF16Count receiving optionally the number of 16-bit units that
* were copied
* @return aBuffer pointer, for convenience
*/
char16_t* UTF8ToUnicodeBuffer(const nsACString& aSource,
char16_t* aBuffer,
uint32_t* aUTF16Count = nullptr);
/**
* Returns a new |char16_t| buffer containing a zero-terminated copy
* of |aSource|.
*
* Allocates and returns a new |char| buffer which you must free with
* |free|. Performs an encoding conversion from UTF-8 to UTF-16
* while copying |aSource| to your new buffer. This conversion is well defined
* for a valid UTF-8 string. The new buffer is zero-terminated, but that
* may not help you if |aSource| contains embedded nulls.
*
* @param aSource an 8-bit wide string, UTF-8 encoded
* @param aUTF16Count the number of 16-bit units that was returned
* @return a new |char16_t| buffer you must free with |free|.
* (UTF-16 encoded)
*/
char16_t* UTF8ToNewUnicode(const nsACString& aSource,
uint32_t* aUTF16Count = nullptr);
/**
* Copies |aLength| 16-bit code units from the start of |aSource| to the
* |char16_t| buffer |aDest|.
*
* After this operation |aDest| is not null terminated.
*
* @param aSource a UTF-16 string
* @param aSrcOffset start offset in the source string
* @param aDest a |char16_t| buffer
* @param aLength the number of 16-bit code units to copy
* @return pointer to destination buffer - identical to |aDest|
*/
char16_t* CopyUnicodeTo(const nsAString& aSource,
uint32_t aSrcOffset,
char16_t* aDest,
uint32_t aLength);
/**
* Copies 16-bit characters between iterators |aSrcStart| and
* |aSrcEnd| to the writable string |aDest|. Similar to the
* |nsString::Mid| method.
*
* After this operation |aDest| is not null terminated.
*
* @param aSrcStart start source iterator
* @param aSrcEnd end source iterator
* @param aDest destination for the copy
*/
void CopyUnicodeTo(const nsAString::const_iterator& aSrcStart,
const nsAString::const_iterator& aSrcEnd,
nsAString& aDest);
/**
* Appends 16-bit characters between iterators |aSrcStart| and
* |aSrcEnd| to the writable string |aDest|.
*
* After this operation |aDest| is not null terminated.
*
* @param aSrcStart start source iterator
* @param aSrcEnd end source iterator
* @param aDest destination for the copy
*/
void AppendUnicodeTo(const nsAString::const_iterator& aSrcStart,
const nsAString::const_iterator& aSrcEnd,
nsAString& aDest);
/**
* Returns |true| if |aString| contains only ASCII characters, that is, characters in the range (0x00, 0x7F).
*
* @param aString a 16-bit wide string to scan
*/
bool IsASCII(const nsAString& aString);
/**
* Returns |true| if |aString| contains only ASCII characters, that is, characters in the range (0x00, 0x7F).
*
* @param aString a 8-bit wide string to scan
*/
bool IsASCII(const nsACString& aString);
/**
* Returns |true| if |aString| is a valid UTF-8 string.
* XXX This is not bullet-proof and nor an all-purpose UTF-8 validator.
* It is mainly written to replace and roughly equivalent to
*
* str.Equals(NS_ConvertUTF16toUTF8(NS_ConvertUTF8toUTF16(str)))
*
* (see bug 191541)
* As such, it does not check for non-UTF-8 7bit encodings such as
* ISO-2022-JP and HZ.
*
* It rejects sequences with the following errors:
*
* byte sequences that cannot be decoded into characters according to
* UTF-8's rules (including cases where the input is part of a valid
* UTF-8 sequence but starts or ends mid-character)
* overlong sequences (i.e., cases where a character was encoded
* non-canonically by using more bytes than necessary)
* surrogate codepoints (i.e., the codepoints reserved for
representing astral characters in UTF-16)
* codepoints above the unicode range (i.e., outside the first 17
* planes; higher than U+10FFFF), in accordance with
* http://tools.ietf.org/html/rfc3629
* when aRejectNonChar is true (the default), any codepoint whose low
* 16 bits are 0xFFFE or 0xFFFF
*
* @param aString an 8-bit wide string to scan
* @param aRejectNonChar a boolean to control the rejection of utf-8
* non characters
*/
bool IsUTF8(const nsACString& aString, bool aRejectNonChar = true);
bool ParseString(const nsACString& aAstring, char aDelimiter,
nsTArray<nsCString>& aArray);
/**
* Converts case in place in the argument string.
*/
void ToUpperCase(nsACString&);
void ToLowerCase(nsACString&);
void ToUpperCase(nsCSubstring&);
void ToLowerCase(nsCSubstring&);
/**
* Converts case from string aSource to aDest.
*/
void ToUpperCase(const nsACString& aSource, nsACString& aDest);
void ToLowerCase(const nsACString& aSource, nsACString& aDest);
/**
* Finds the leftmost occurrence of |aPattern|, if any in the range |aSearchStart|..|aSearchEnd|.
*
* Returns |true| if a match was found, and adjusts |aSearchStart| and |aSearchEnd| to
* point to the match. If no match was found, returns |false| and makes |aSearchStart == aSearchEnd|.
*
* Currently, this is equivalent to the O(m*n) implementation previously on |ns[C]String|.
* If we need something faster, then we can implement that later.
*/
bool FindInReadable(const nsAString& aPattern, nsAString::const_iterator&,
nsAString::const_iterator&,
const nsStringComparator& = nsDefaultStringComparator());
bool FindInReadable(const nsACString& aPattern, nsACString::const_iterator&,
nsACString::const_iterator&,
const nsCStringComparator& = nsDefaultCStringComparator());
/* sometimes we don't care about where the string was, just that we
* found it or not */
inline bool
FindInReadable(const nsAString& aPattern, const nsAString& aSource,
const nsStringComparator& aCompare = nsDefaultStringComparator())
{
nsAString::const_iterator start, end;
aSource.BeginReading(start);
aSource.EndReading(end);
return FindInReadable(aPattern, start, end, aCompare);
}
inline bool
FindInReadable(const nsACString& aPattern, const nsACString& aSource,
const nsCStringComparator& aCompare = nsDefaultCStringComparator())
{
nsACString::const_iterator start, end;
aSource.BeginReading(start);
aSource.EndReading(end);
return FindInReadable(aPattern, start, end, aCompare);
}
bool CaseInsensitiveFindInReadable(const nsACString& aPattern,
nsACString::const_iterator&,
nsACString::const_iterator&);
/**
* Finds the rightmost occurrence of |aPattern|
* Returns |true| if a match was found, and adjusts |aSearchStart| and |aSearchEnd| to
* point to the match. If no match was found, returns |false| and makes |aSearchStart == aSearchEnd|.
*
*/
bool RFindInReadable(const nsAString& aPattern, nsAString::const_iterator&,
nsAString::const_iterator&,
const nsStringComparator& = nsDefaultStringComparator());
bool RFindInReadable(const nsACString& aPattern, nsACString::const_iterator&,
nsACString::const_iterator&,
const nsCStringComparator& = nsDefaultCStringComparator());
/**
* Finds the leftmost occurrence of |aChar|, if any in the range
* |aSearchStart|..|aSearchEnd|.
*
* Returns |true| if a match was found, and adjusts |aSearchStart| to
* point to the match. If no match was found, returns |false| and
* makes |aSearchStart == aSearchEnd|.
*/
bool FindCharInReadable(char16_t aChar, nsAString::const_iterator& aSearchStart,
const nsAString::const_iterator& aSearchEnd);
bool FindCharInReadable(char aChar, nsACString::const_iterator& aSearchStart,
const nsACString::const_iterator& aSearchEnd);
/**
* Finds the number of occurences of |aChar| in the string |aStr|
*/
uint32_t CountCharInReadable(const nsAString& aStr,
char16_t aChar);
uint32_t CountCharInReadable(const nsACString& aStr,
char aChar);
bool StringBeginsWith(const nsAString& aSource, const nsAString& aSubstring);
bool StringBeginsWith(const nsAString& aSource, const nsAString& aSubstring,
const nsStringComparator& aComparator);
bool StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring);
bool StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring,
const nsCStringComparator& aComparator);
bool StringEndsWith(const nsAString& aSource, const nsAString& aSubstring);
bool StringEndsWith(const nsAString& aSource, const nsAString& aSubstring,
const nsStringComparator& aComparator);
bool StringEndsWith(const nsACString& aSource, const nsACString& aSubstring);
bool StringEndsWith(const nsACString& aSource, const nsACString& aSubstring,
const nsCStringComparator& aComparator);
const nsAFlatString& EmptyString();
const nsAFlatCString& EmptyCString();
const nsAFlatString& NullString();
const nsAFlatCString& NullCString();
/**
* Compare a UTF-8 string to an UTF-16 string.
*
* Returns 0 if the strings are equal, -1 if aUTF8String is less
* than aUTF16Count, and 1 in the reverse case. In case of fatal
* error (eg the strings are not valid UTF8 and UTF16 respectively),
* this method will return INT32_MIN.
*/
int32_t CompareUTF8toUTF16(const nsASingleFragmentCString& aUTF8String,
const nsASingleFragmentString& aUTF16String);
void AppendUCS4ToUTF16(const uint32_t aSource, nsAString& aDest);
template<class T>
inline bool
EnsureStringLength(T& aStr, uint32_t aLen)
{
aStr.SetLength(aLen);
return (aStr.Length() == aLen);
}
#endif // !defined(nsReadableUtils_h___)