xpcom/string/nsReadableUtils.h
author Mike Hommey <mh+mozilla@glandium.org>
Thu, 30 Oct 2014 13:06:12 +0900
changeset 213063 55d15b285436576e1c5979f753e433c50fd9db3a
parent 191042 39192ab47239c73817b4ec8090f4ef498b2110e2
child 223901 27ae894ee4d70e08dea4e335352aa2afd810e82a
permissions -rw-r--r--
Bug 1077148 part 4 - Add and use new moz.build templates for Gecko programs and libraries. r=gps There are, sadly, many combinations of linkage in use throughout the tree. The main differentiator, though, is between program/libraries related to Gecko or not. Kind of. Some need mozglue, some don't. Some need dependent linkage, some standalone. Anyways, these new templates remove the need to manually define the right dependencies against xpcomglue, nspr, mozalloc and mozglue in most cases. Places that build programs and were resetting MOZ_GLUE_PROGRAM_LDFLAGS or that build libraries and were resetting MOZ_GLUE_LDFLAGS can now just not use those Gecko-specific templates.

/* -*- 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 char16_t* aSource, nsACString& aDest);
void CopyASCIItoUTF16(const char* aSource, nsAString& aDest);

void CopyUTF16toUTF8(const nsAString& aSource, nsACString& aDest);
void CopyUTF8toUTF16(const nsACString& aSource, nsAString& aDest);

void CopyUTF16toUTF8(const char16_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);
NS_WARN_UNUSED_RESULT bool AppendASCIItoUTF16(const nsACString& aSource,
                                              nsAString& aDest,
                                              const mozilla::fallible_t&);

void LossyAppendUTF16toASCII(const char16_t* aSource, nsACString& aDest);
void AppendASCIItoUTF16(const char* aSource, nsAString& aDest);

void AppendUTF16toUTF8(const nsAString& aSource, nsACString& aDest);
NS_WARN_UNUSED_RESULT bool AppendUTF16toUTF8(const nsAString& aSource,
                                             nsACString& aDest,
                                             const mozilla::fallible_t&);
void AppendUTF8toUTF16(const nsACString& aSource, nsAString& aDest);
NS_WARN_UNUSED_RESULT bool AppendUTF8toUTF16(const nsACString& aSource,
                                             nsAString& aDest,
                                             const mozilla::fallible_t&);

void AppendUTF16toUTF8(const char16_t* aSource, nsACString& aDest);
void AppendUTF8toUTF16(const char* aSource, nsAString& aDest);

#ifdef MOZ_USE_CHAR16_WRAPPER
inline void AppendUTF16toUTF8(char16ptr_t aSource, nsACString& aDest)
{
  return AppendUTF16toUTF8(static_cast<const char16_t*>(aSource), aDest);
}
#endif

/**
 * Returns a new |char| buffer containing a zero-terminated copy of |aSource|.
 *
 * Allocates and returns a new |char| buffer which you must free with |nsMemory::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 |nsMemory::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 |nsMemory::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 |nsMemory::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
 * |nsMemory::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 |nsMemory::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
 * |nsMemory::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 |nsMemory::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 |nsMemory::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 |nsMemory::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
 * |nsMemory::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 |nsMemory::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,
                      const nsStringComparator& aComparator =
                        nsDefaultStringComparator());
bool StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring,
                      const nsCStringComparator& aComparator =
                        nsDefaultCStringComparator());
bool StringEndsWith(const nsAString& aSource, const nsAString& aSubstring,
                    const nsStringComparator& aComparator =
                      nsDefaultStringComparator());
bool StringEndsWith(const nsACString& aSource, const nsACString& aSubstring,
                    const nsCStringComparator& aComparator =
                      nsDefaultCStringComparator());

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___)