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gecko-dev/xpcom/string/nsReadableUtils.cpp

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C++
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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/. */
#include "nsReadableUtils.h"
#include "nsReadableUtilsImpl.h"
#include <algorithm>
#include "mozilla/CheckedInt.h"
#include "nscore.h"
#include "nsMemory.h"
#include "nsString.h"
#include "nsTArray.h"
#include "nsUTF8Utils.h"
using mozilla::IsASCII;
/**
* Fallback implementation for finding the first non-ASCII character in a
* UTF-16 string.
*/
static inline int32_t
FirstNonASCIIUnvectorized(const char16_t* aBegin, const char16_t* aEnd)
{
typedef mozilla::NonASCIIParameters<sizeof(size_t)> p;
const size_t kMask = p::mask();
const uintptr_t kAlignMask = p::alignMask();
const size_t kNumUnicharsPerWord = p::numUnicharsPerWord();
const char16_t* idx = aBegin;
// Align ourselves to a word boundary.
for (; idx != aEnd && ((uintptr_t(idx) & kAlignMask) != 0); idx++) {
if (!IsASCII(*idx)) {
return idx - aBegin;
}
}
// Check one word at a time.
const char16_t* wordWalkEnd = mozilla::aligned(aEnd, kAlignMask);
for (; idx != wordWalkEnd; idx += kNumUnicharsPerWord) {
const size_t word = *reinterpret_cast<const size_t*>(idx);
if (word & kMask) {
return idx - aBegin;
}
}
// Take care of the remainder one character at a time.
for (; idx != aEnd; idx++) {
if (!IsASCII(*idx)) {
return idx - aBegin;
}
}
return -1;
}
/*
* This function returns -1 if all characters in str are ASCII characters.
* Otherwise, it returns a value less than or equal to the index of the first
* ASCII character in str. For example, if first non-ASCII character is at
* position 25, it may return 25, 24, or 16. But it guarantees
* there are only ASCII characters before returned value.
*/
static inline int32_t
FirstNonASCII(const char16_t* aBegin, const char16_t* aEnd)
{
#ifdef MOZILLA_MAY_SUPPORT_SSE2
if (mozilla::supports_sse2()) {
return mozilla::SSE2::FirstNonASCII(aBegin, aEnd);
}
#endif
return FirstNonASCIIUnvectorized(aBegin, aEnd);
}
void
LossyCopyUTF16toASCII(const nsAString& aSource, nsACString& aDest)
{
aDest.Truncate();
LossyAppendUTF16toASCII(aSource, aDest);
}
void
CopyASCIItoUTF16(const nsACString& aSource, nsAString& aDest)
{
if (!CopyASCIItoUTF16(aSource, aDest, mozilla::fallible)) {
// Note that this may wildly underestimate the allocation that failed, as
// we report the length of aSource as UTF-16 instead of UTF-8.
aDest.AllocFailed(aDest.Length() + aSource.Length());
}
}
bool
CopyASCIItoUTF16(const nsACString& aSource, nsAString& aDest,
const mozilla::fallible_t& aFallible)
{
aDest.Truncate();
return AppendASCIItoUTF16(aSource, aDest, aFallible);
}
void
LossyCopyUTF16toASCII(const char16ptr_t aSource, nsACString& aDest)
{
aDest.Truncate();
if (aSource) {
LossyAppendUTF16toASCII(nsDependentString(aSource), aDest);
}
}
void
CopyASCIItoUTF16(const char* aSource, nsAString& aDest)
{
aDest.Truncate();
if (aSource) {
AppendASCIItoUTF16(nsDependentCString(aSource), aDest);
}
}
void
CopyUTF16toUTF8(const nsAString& aSource, nsACString& aDest)
{
if (!CopyUTF16toUTF8(aSource, aDest, mozilla::fallible)) {
// Note that this may wildly underestimate the allocation that failed, as
// we report the length of aSource as UTF-16 instead of UTF-8.
aDest.AllocFailed(aDest.Length() + aSource.Length());
}
}
bool
CopyUTF16toUTF8(const nsAString& aSource, nsACString& aDest,
const mozilla::fallible_t& aFallible)
{
aDest.Truncate();
if (!AppendUTF16toUTF8(aSource, aDest, aFallible)) {
return false;
}
return true;
}
void
CopyUTF8toUTF16(const nsACString& aSource, nsAString& aDest)
{
aDest.Truncate();
AppendUTF8toUTF16(aSource, aDest);
}
void
CopyUTF16toUTF8(const char16ptr_t aSource, nsACString& aDest)
{
aDest.Truncate();
AppendUTF16toUTF8(aSource, aDest);
}
void
CopyUTF8toUTF16(const char* aSource, nsAString& aDest)
{
aDest.Truncate();
AppendUTF8toUTF16(aSource, aDest);
}
void
LossyAppendUTF16toASCII(const nsAString& aSource, nsACString& aDest)
{
uint32_t old_dest_length = aDest.Length();
aDest.SetLength(old_dest_length + aSource.Length());
nsAString::const_iterator fromBegin, fromEnd;
nsACString::iterator dest;
aDest.BeginWriting(dest);
dest.advance(old_dest_length);
// right now, this won't work on multi-fragment destinations
LossyConvertEncoding16to8 converter(dest.get());
copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
converter);
}
void
AppendASCIItoUTF16(const nsACString& aSource, nsAString& aDest)
{
if (!AppendASCIItoUTF16(aSource, aDest, mozilla::fallible)) {
aDest.AllocFailed(aDest.Length() + aSource.Length());
}
}
bool
AppendASCIItoUTF16(const nsACString& aSource, nsAString& aDest,
const mozilla::fallible_t& aFallible)
{
uint32_t old_dest_length = aDest.Length();
if (!aDest.SetLength(old_dest_length + aSource.Length(),
aFallible)) {
return false;
}
nsACString::const_iterator fromBegin, fromEnd;
nsAString::iterator dest;
aDest.BeginWriting(dest);
dest.advance(old_dest_length);
// right now, this won't work on multi-fragment destinations
LossyConvertEncoding8to16 converter(dest.get());
copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
converter);
return true;
}
void
LossyAppendUTF16toASCII(const char16ptr_t aSource, nsACString& aDest)
{
if (aSource) {
LossyAppendUTF16toASCII(nsDependentString(aSource), aDest);
}
}
bool
AppendASCIItoUTF16(const char* aSource, nsAString& aDest, const mozilla::fallible_t& aFallible)
{
if (aSource) {
return AppendASCIItoUTF16(nsDependentCString(aSource), aDest, aFallible);
}
return true;
}
void
AppendASCIItoUTF16(const char* aSource, nsAString& aDest)
{
if (aSource) {
AppendASCIItoUTF16(nsDependentCString(aSource), aDest);
}
}
void
AppendUTF16toUTF8(const nsAString& aSource, nsACString& aDest)
{
if (!AppendUTF16toUTF8(aSource, aDest, mozilla::fallible)) {
// Note that this may wildly underestimate the allocation that failed, as
// we report the length of aSource as UTF-16 instead of UTF-8.
aDest.AllocFailed(aDest.Length() + aSource.Length());
}
}
bool
AppendUTF16toUTF8(const nsAString& aSource, nsACString& aDest,
const mozilla::fallible_t& aFallible)
{
// At 16 characters analysis showed better performance of both the all ASCII
// and non-ASCII cases, so we limit calling |FirstNonASCII| to strings of
// that length.
const nsAString::size_type kFastPathMinLength = 16;
int32_t firstNonASCII = 0;
if (aSource.Length() >= kFastPathMinLength) {
firstNonASCII = FirstNonASCII(aSource.BeginReading(), aSource.EndReading());
}
if (firstNonASCII == -1) {
// This is all ASCII, we can use the more efficient lossy append.
mozilla::CheckedInt<nsACString::size_type> new_length(aSource.Length());
new_length += aDest.Length();
if (!new_length.isValid() ||
!aDest.SetCapacity(new_length.value(), aFallible)) {
return false;
}
LossyAppendUTF16toASCII(aSource, aDest);
return true;
}
nsAString::const_iterator source_start, source_end;
CalculateUTF8Size calculator;
aSource.BeginReading(source_start);
aSource.EndReading(source_end);
// Skip the characters that we know are single byte.
source_start.advance(firstNonASCII);
copy_string(source_start,
source_end, calculator);
// Include the ASCII characters that were skipped in the count.
size_t count = calculator.Size() + firstNonASCII;
if (count) {
auto old_dest_length = aDest.Length();
// Grow the buffer if we need to.
mozilla::CheckedInt<nsACString::size_type> new_length(count);
new_length += old_dest_length;
if (!new_length.isValid() ||
!aDest.SetLength(new_length.value(), aFallible)) {
return false;
}
// All ready? Time to convert
nsAString::const_iterator ascii_end;
aSource.BeginReading(ascii_end);
if (firstNonASCII >= static_cast<int32_t>(kFastPathMinLength)) {
// Use the more efficient lossy converter for the ASCII portion.
LossyConvertEncoding16to8 lossy_converter(
aDest.BeginWriting() + old_dest_length);
nsAString::const_iterator ascii_start;
aSource.BeginReading(ascii_start);
ascii_end.advance(firstNonASCII);
copy_string(ascii_start, ascii_end, lossy_converter);
} else {
// Not using the lossy shortcut, we need to include the leading ASCII
// chars.
firstNonASCII = 0;
}
ConvertUTF16toUTF8 converter(
aDest.BeginWriting() + old_dest_length + firstNonASCII);
copy_string(ascii_end,
aSource.EndReading(source_end), converter);
NS_ASSERTION(converter.Size() == count - firstNonASCII,
"Unexpected disparity between CalculateUTF8Size and "
"ConvertUTF16toUTF8");
}
return true;
}
void
AppendUTF8toUTF16(const nsACString& aSource, nsAString& aDest)
{
if (!AppendUTF8toUTF16(aSource, aDest, mozilla::fallible)) {
aDest.AllocFailed(aDest.Length() + aSource.Length());
}
}
bool
AppendUTF8toUTF16(const nsACString& aSource, nsAString& aDest,
const mozilla::fallible_t& aFallible)
{
nsACString::const_iterator source_start, source_end;
CalculateUTF8Length calculator;
copy_string(aSource.BeginReading(source_start),
aSource.EndReading(source_end), calculator);
uint32_t count = calculator.Length();
// Avoid making the string mutable if we're appending an empty string
if (count) {
uint32_t old_dest_length = aDest.Length();
// Grow the buffer if we need to.
if (!aDest.SetLength(old_dest_length + count, aFallible)) {
return false;
}
// All ready? Time to convert
ConvertUTF8toUTF16 converter(aDest.BeginWriting() + old_dest_length);
copy_string(aSource.BeginReading(source_start),
aSource.EndReading(source_end), converter);
NS_ASSERTION(converter.ErrorEncountered() ||
converter.Length() == count,
"CalculateUTF8Length produced the wrong length");
if (converter.ErrorEncountered()) {
NS_ERROR("Input wasn't UTF8 or incorrect length was calculated");
aDest.SetLength(old_dest_length);
}
}
return true;
}
void
AppendUTF16toUTF8(const char16ptr_t aSource, nsACString& aDest)
{
if (aSource) {
AppendUTF16toUTF8(nsDependentString(aSource), aDest);
}
}
void
AppendUTF8toUTF16(const char* aSource, nsAString& aDest)
{
if (aSource) {
AppendUTF8toUTF16(nsDependentCString(aSource), aDest);
}
}
/**
* A helper function that allocates a buffer of the desired character type big enough to hold a copy of the supplied string (plus a zero terminator).
*
* @param aSource an string you will eventually be making a copy of
* @return a new buffer (of the type specified by the second parameter) which you must free with |free|.
*
*/
template <class FromStringT, class ToCharT>
inline
ToCharT*
AllocateStringCopy(const FromStringT& aSource, ToCharT*)
{
return static_cast<ToCharT*>(moz_xmalloc(
(aSource.Length() + 1) * sizeof(ToCharT)));
}
char*
ToNewCString(const nsAString& aSource)
{
char* result = AllocateStringCopy(aSource, (char*)0);
if (!result) {
return nullptr;
}
nsAString::const_iterator fromBegin, fromEnd;
LossyConvertEncoding16to8 converter(result);
copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
converter).write_terminator();
return result;
}
char*
ToNewUTF8String(const nsAString& aSource, uint32_t* aUTF8Count)
{
nsAString::const_iterator start, end;
CalculateUTF8Size calculator;
copy_string(aSource.BeginReading(start), aSource.EndReading(end),
calculator);
if (aUTF8Count) {
*aUTF8Count = calculator.Size();
}
char* result = static_cast<char*>
(moz_xmalloc(calculator.Size() + 1));
if (!result) {
return nullptr;
}
ConvertUTF16toUTF8 converter(result);
copy_string(aSource.BeginReading(start), aSource.EndReading(end),
converter).write_terminator();
NS_ASSERTION(calculator.Size() == converter.Size(), "length mismatch");
return result;
}
char*
ToNewCString(const nsACString& aSource)
{
// no conversion needed, just allocate a buffer of the correct length and copy into it
char* result = AllocateStringCopy(aSource, (char*)0);
if (!result) {
return nullptr;
}
nsACString::const_iterator fromBegin, fromEnd;
char* toBegin = result;
*copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
toBegin) = char(0);
return result;
}
char16_t*
ToNewUnicode(const nsAString& aSource)
{
// no conversion needed, just allocate a buffer of the correct length and copy into it
char16_t* result = AllocateStringCopy(aSource, (char16_t*)0);
if (!result) {
return nullptr;
}
nsAString::const_iterator fromBegin, fromEnd;
char16_t* toBegin = result;
*copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
toBegin) = char16_t(0);
return result;
}
char16_t*
ToNewUnicode(const nsACString& aSource)
{
char16_t* result = AllocateStringCopy(aSource, (char16_t*)0);
if (!result) {
return nullptr;
}
nsACString::const_iterator fromBegin, fromEnd;
LossyConvertEncoding8to16 converter(result);
copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
converter).write_terminator();
return result;
}
uint32_t
CalcUTF8ToUnicodeLength(const nsACString& aSource)
{
nsACString::const_iterator start, end;
CalculateUTF8Length calculator;
copy_string(aSource.BeginReading(start), aSource.EndReading(end),
calculator);
return calculator.Length();
}
char16_t*
UTF8ToUnicodeBuffer(const nsACString& aSource, char16_t* aBuffer,
uint32_t* aUTF16Count)
{
nsACString::const_iterator start, end;
ConvertUTF8toUTF16 converter(aBuffer);
copy_string(aSource.BeginReading(start),
aSource.EndReading(end),
converter).write_terminator();
if (aUTF16Count) {
*aUTF16Count = converter.Length();
}
return aBuffer;
}
char16_t*
UTF8ToNewUnicode(const nsACString& aSource, uint32_t* aUTF16Count)
{
const uint32_t length = CalcUTF8ToUnicodeLength(aSource);
const size_t buffer_size = (length + 1) * sizeof(char16_t);
char16_t* buffer = static_cast<char16_t*>(moz_xmalloc(buffer_size));
if (!buffer) {
return nullptr;
}
uint32_t copied;
UTF8ToUnicodeBuffer(aSource, buffer, &copied);
NS_ASSERTION(length == copied, "length mismatch");
if (aUTF16Count) {
*aUTF16Count = copied;
}
return buffer;
}
char16_t*
CopyUnicodeTo(const nsAString& aSource, uint32_t aSrcOffset, char16_t* aDest,
uint32_t aLength)
{
nsAString::const_iterator fromBegin, fromEnd;
char16_t* toBegin = aDest;
copy_string(aSource.BeginReading(fromBegin).advance(int32_t(aSrcOffset)),
aSource.BeginReading(fromEnd).advance(int32_t(aSrcOffset + aLength)),
toBegin);
return aDest;
}
void
CopyUnicodeTo(const nsAString::const_iterator& aSrcStart,
const nsAString::const_iterator& aSrcEnd,
nsAString& aDest)
{
aDest.SetLength(Distance(aSrcStart, aSrcEnd));
nsAString::char_iterator dest = aDest.BeginWriting();
nsAString::const_iterator fromBegin(aSrcStart);
copy_string(fromBegin, aSrcEnd, dest);
}
void
AppendUnicodeTo(const nsAString::const_iterator& aSrcStart,
const nsAString::const_iterator& aSrcEnd,
nsAString& aDest)
{
uint32_t oldLength = aDest.Length();
aDest.SetLength(oldLength + Distance(aSrcStart, aSrcEnd));
nsAString::char_iterator dest = aDest.BeginWriting() + oldLength;
nsAString::const_iterator fromBegin(aSrcStart);
copy_string(fromBegin, aSrcEnd, dest);
}
bool
IsASCII(const nsAString& aString)
{
static const char16_t NOT_ASCII = char16_t(~0x007F);
// Don't want to use |copy_string| for this task, since we can stop at the first non-ASCII character
nsAString::const_iterator iter, done_reading;
aString.BeginReading(iter);
aString.EndReading(done_reading);
const char16_t* c = iter.get();
const char16_t* end = done_reading.get();
while (c < end) {
if (*c++ & NOT_ASCII) {
return false;
}
}
return true;
}
bool
IsASCII(const nsACString& aString)
{
static const char NOT_ASCII = char(~0x7F);
// Don't want to use |copy_string| for this task, since we can stop at the first non-ASCII character
nsACString::const_iterator iter, done_reading;
aString.BeginReading(iter);
aString.EndReading(done_reading);
const char* c = iter.get();
const char* end = done_reading.get();
while (c < end) {
if (*c++ & NOT_ASCII) {
return false;
}
}
return true;
}
bool
IsUTF8(const nsACString& aString, bool aRejectNonChar)
{
nsReadingIterator<char> done_reading;
aString.EndReading(done_reading);
int32_t state = 0;
bool overlong = false;
bool surrogate = false;
bool nonchar = false;
uint16_t olupper = 0; // overlong byte upper bound.
uint16_t slower = 0; // surrogate byte lower bound.
nsReadingIterator<char> iter;
aString.BeginReading(iter);
const char* ptr = iter.get();
const char* end = done_reading.get();
while (ptr < end) {
uint8_t c;
if (0 == state) {
c = *ptr++;
if (UTF8traits::isASCII(c)) {
continue;
}
if (c <= 0xC1) { // [80-BF] where not expected, [C0-C1] for overlong.
return false;
} else if (UTF8traits::is2byte(c)) {
state = 1;
} else if (UTF8traits::is3byte(c)) {
state = 2;
if (c == 0xE0) { // to exclude E0[80-9F][80-BF]
overlong = true;
olupper = 0x9F;
} else if (c == 0xED) { // ED[A0-BF][80-BF] : surrogate codepoint
surrogate = true;
slower = 0xA0;
} else if (c == 0xEF) { // EF BF [BE-BF] : non-character
nonchar = true;
}
} else if (c <= 0xF4) { // XXX replace /w UTF8traits::is4byte when it's updated to exclude [F5-F7].(bug 199090)
state = 3;
nonchar = true;
if (c == 0xF0) { // to exclude F0[80-8F][80-BF]{2}
overlong = true;
olupper = 0x8F;
} else if (c == 0xF4) { // to exclude F4[90-BF][80-BF]
// actually not surrogates but codepoints beyond 0x10FFFF
surrogate = true;
slower = 0x90;
}
} else {
return false; // Not UTF-8 string
}
}
if (nonchar && !aRejectNonChar) {
nonchar = false;
}
while (ptr < end && state) {
c = *ptr++;
--state;
// non-character : EF BF [BE-BF] or F[0-7] [89AB]F BF [BE-BF]
if (nonchar &&
((!state && c < 0xBE) ||
(state == 1 && c != 0xBF) ||
(state == 2 && 0x0F != (0x0F & c)))) {
nonchar = false;
}
if (!UTF8traits::isInSeq(c) || (overlong && c <= olupper) ||
(surrogate && slower <= c) || (nonchar && !state)) {
return false; // Not UTF-8 string
}
overlong = surrogate = false;
}
}
return !state; // state != 0 at the end indicates an invalid UTF-8 seq.
}
/**
* A character sink for in-place case conversion.
*/
class ConvertToUpperCase
{
public:
typedef char value_type;
uint32_t
write(const char* aSource, uint32_t aSourceLength)
{
char* cp = const_cast<char*>(aSource);
const char* end = aSource + aSourceLength;
while (cp != end) {
char ch = *cp;
if (ch >= 'a' && ch <= 'z') {
*cp = ch - ('a' - 'A');
}
++cp;
}
return aSourceLength;
}
};
void
ToUpperCase(nsACString& aCString)
{
ConvertToUpperCase converter;
char* start;
converter.write(aCString.BeginWriting(start), aCString.Length());
}
/**
* A character sink for copying with case conversion.
*/
class CopyToUpperCase
{
public:
typedef char value_type;
explicit CopyToUpperCase(nsACString::iterator& aDestIter,
const nsACString::iterator& aEndIter)
: mIter(aDestIter)
, mEnd(aEndIter)
{
}
uint32_t
write(const char* aSource, uint32_t aSourceLength)
{
uint32_t len = XPCOM_MIN(uint32_t(mEnd - mIter), aSourceLength);
char* cp = mIter.get();
const char* end = aSource + len;
while (aSource != end) {
char ch = *aSource;
if ((ch >= 'a') && (ch <= 'z')) {
*cp = ch - ('a' - 'A');
} else {
*cp = ch;
}
++aSource;
++cp;
}
mIter.advance(len);
return len;
}
protected:
nsACString::iterator& mIter;
const nsACString::iterator& mEnd;
};
void
ToUpperCase(const nsACString& aSource, nsACString& aDest)
{
nsACString::const_iterator fromBegin, fromEnd;
nsACString::iterator toBegin, toEnd;
aDest.SetLength(aSource.Length());
CopyToUpperCase converter(aDest.BeginWriting(toBegin), aDest.EndWriting(toEnd));
copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
converter);
}
/**
* A character sink for case conversion.
*/
class ConvertToLowerCase
{
public:
typedef char value_type;
uint32_t
write(const char* aSource, uint32_t aSourceLength)
{
char* cp = const_cast<char*>(aSource);
const char* end = aSource + aSourceLength;
while (cp != end) {
char ch = *cp;
if ((ch >= 'A') && (ch <= 'Z')) {
*cp = ch + ('a' - 'A');
}
++cp;
}
return aSourceLength;
}
};
void
ToLowerCase(nsACString& aCString)
{
ConvertToLowerCase converter;
char* start;
converter.write(aCString.BeginWriting(start), aCString.Length());
}
/**
* A character sink for copying with case conversion.
*/
class CopyToLowerCase
{
public:
typedef char value_type;
explicit CopyToLowerCase(nsACString::iterator& aDestIter,
const nsACString::iterator& aEndIter)
: mIter(aDestIter)
, mEnd(aEndIter)
{
}
uint32_t
write(const char* aSource, uint32_t aSourceLength)
{
uint32_t len = XPCOM_MIN(uint32_t(mEnd - mIter), aSourceLength);
char* cp = mIter.get();
const char* end = aSource + len;
while (aSource != end) {
char ch = *aSource;
if ((ch >= 'A') && (ch <= 'Z')) {
*cp = ch + ('a' - 'A');
} else {
*cp = ch;
}
++aSource;
++cp;
}
mIter.advance(len);
return len;
}
protected:
nsACString::iterator& mIter;
const nsACString::iterator& mEnd;
};
void
ToLowerCase(const nsACString& aSource, nsACString& aDest)
{
nsACString::const_iterator fromBegin, fromEnd;
nsACString::iterator toBegin, toEnd;
aDest.SetLength(aSource.Length());
CopyToLowerCase converter(aDest.BeginWriting(toBegin), aDest.EndWriting(toEnd));
copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd),
converter);
}
bool
ParseString(const nsACString& aSource, char aDelimiter,
nsTArray<nsCString>& aArray)
{
nsACString::const_iterator start, end;
aSource.BeginReading(start);
aSource.EndReading(end);
uint32_t oldLength = aArray.Length();
for (;;) {
nsACString::const_iterator delimiter = start;
FindCharInReadable(aDelimiter, delimiter, end);
if (delimiter != start) {
if (!aArray.AppendElement(Substring(start, delimiter))) {
aArray.RemoveElementsAt(oldLength, aArray.Length() - oldLength);
return false;
}
}
if (delimiter == end) {
break;
}
start = ++delimiter;
if (start == end) {
break;
}
}
return true;
}
template <class StringT, class IteratorT, class Comparator>
bool
FindInReadable_Impl(const StringT& aPattern, IteratorT& aSearchStart,
IteratorT& aSearchEnd, const Comparator& aCompare)
{
bool found_it = false;
// only bother searching at all if we're given a non-empty range to search
if (aSearchStart != aSearchEnd) {
IteratorT aPatternStart, aPatternEnd;
aPattern.BeginReading(aPatternStart);
aPattern.EndReading(aPatternEnd);
// outer loop keeps searching till we find it or run out of string to search
while (!found_it) {
// fast inner loop (that's what it's called, not what it is) looks for a potential match
while (aSearchStart != aSearchEnd &&
aCompare(aPatternStart.get(), aSearchStart.get(), 1, 1)) {
++aSearchStart;
}
// if we broke out of the `fast' loop because we're out of string ... we're done: no match
if (aSearchStart == aSearchEnd) {
break;
}
// otherwise, we're at a potential match, let's see if we really hit one
IteratorT testPattern(aPatternStart);
IteratorT testSearch(aSearchStart);
// slow inner loop verifies the potential match (found by the `fast' loop) at the current position
for (;;) {
// we already compared the first character in the outer loop,
// so we'll advance before the next comparison
++testPattern;
++testSearch;
// if we verified all the way to the end of the pattern, then we found it!
if (testPattern == aPatternEnd) {
found_it = true;
aSearchEnd = testSearch; // return the exact found range through the parameters
break;
}
// if we got to end of the string we're searching before we hit the end of the
// pattern, we'll never find what we're looking for
if (testSearch == aSearchEnd) {
aSearchStart = aSearchEnd;
break;
}
// else if we mismatched ... it's time to advance to the next search position
// and get back into the `fast' loop
if (aCompare(testPattern.get(), testSearch.get(), 1, 1)) {
++aSearchStart;
break;
}
}
}
}
return found_it;
}
/**
* This searches the entire string from right to left, and returns the first match found, if any.
*/
template <class StringT, class IteratorT, class Comparator>
bool
RFindInReadable_Impl(const StringT& aPattern, IteratorT& aSearchStart,
IteratorT& aSearchEnd, const Comparator& aCompare)
{
IteratorT patternStart, patternEnd, searchEnd = aSearchEnd;
aPattern.BeginReading(patternStart);
aPattern.EndReading(patternEnd);
// Point to the last character in the pattern
--patternEnd;
// outer loop keeps searching till we run out of string to search
while (aSearchStart != searchEnd) {
// Point to the end position of the next possible match
--searchEnd;
// Check last character, if a match, explore further from here
if (aCompare(patternEnd.get(), searchEnd.get(), 1, 1) == 0) {
// We're at a potential match, let's see if we really hit one
IteratorT testPattern(patternEnd);
IteratorT testSearch(searchEnd);
// inner loop verifies the potential match at the current position
do {
// if we verified all the way to the end of the pattern, then we found it!
if (testPattern == patternStart) {
aSearchStart = testSearch; // point to start of match
aSearchEnd = ++searchEnd; // point to end of match
return true;
}
// if we got to end of the string we're searching before we hit the end of the
// pattern, we'll never find what we're looking for
if (testSearch == aSearchStart) {
aSearchStart = aSearchEnd;
return false;
}
// test previous character for a match
--testPattern;
--testSearch;
} while (aCompare(testPattern.get(), testSearch.get(), 1, 1) == 0);
}
}
aSearchStart = aSearchEnd;
return false;
}
bool
FindInReadable(const nsAString& aPattern,
nsAString::const_iterator& aSearchStart,
nsAString::const_iterator& aSearchEnd,
const nsStringComparator& aComparator)
{
return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
}
bool
FindInReadable(const nsACString& aPattern,
nsACString::const_iterator& aSearchStart,
nsACString::const_iterator& aSearchEnd,
const nsCStringComparator& aComparator)
{
return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
}
bool
CaseInsensitiveFindInReadable(const nsACString& aPattern,
nsACString::const_iterator& aSearchStart,
nsACString::const_iterator& aSearchEnd)
{
return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd,
nsCaseInsensitiveCStringComparator());
}
bool
RFindInReadable(const nsAString& aPattern,
nsAString::const_iterator& aSearchStart,
nsAString::const_iterator& aSearchEnd,
const nsStringComparator& aComparator)
{
return RFindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
}
bool
RFindInReadable(const nsACString& aPattern,
nsACString::const_iterator& aSearchStart,
nsACString::const_iterator& aSearchEnd,
const nsCStringComparator& aComparator)
{
return RFindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
}
bool
FindCharInReadable(char16_t aChar, nsAString::const_iterator& aSearchStart,
const nsAString::const_iterator& aSearchEnd)
{
int32_t fragmentLength = aSearchEnd.get() - aSearchStart.get();
const char16_t* charFoundAt =
nsCharTraits<char16_t>::find(aSearchStart.get(), fragmentLength, aChar);
if (charFoundAt) {
aSearchStart.advance(charFoundAt - aSearchStart.get());
return true;
}
aSearchStart.advance(fragmentLength);
return false;
}
bool
FindCharInReadable(char aChar, nsACString::const_iterator& aSearchStart,
const nsACString::const_iterator& aSearchEnd)
{
int32_t fragmentLength = aSearchEnd.get() - aSearchStart.get();
const char* charFoundAt =
nsCharTraits<char>::find(aSearchStart.get(), fragmentLength, aChar);
if (charFoundAt) {
aSearchStart.advance(charFoundAt - aSearchStart.get());
return true;
}
aSearchStart.advance(fragmentLength);
return false;
}
uint32_t
CountCharInReadable(const nsAString& aStr, char16_t aChar)
{
uint32_t count = 0;
nsAString::const_iterator begin, end;
aStr.BeginReading(begin);
aStr.EndReading(end);
while (begin != end) {
if (*begin == aChar) {
++count;
}
++begin;
}
return count;
}
uint32_t
CountCharInReadable(const nsACString& aStr, char aChar)
{
uint32_t count = 0;
nsACString::const_iterator begin, end;
aStr.BeginReading(begin);
aStr.EndReading(end);
while (begin != end) {
if (*begin == aChar) {
++count;
}
++begin;
}
return count;
}
bool
StringBeginsWith(const nsAString& aSource, const nsAString& aSubstring)
{
nsAString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, 0, sub_len).Equals(aSubstring);
}
bool
StringBeginsWith(const nsAString& aSource, const nsAString& aSubstring,
const nsStringComparator& aComparator)
{
nsAString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, 0, sub_len).Equals(aSubstring, aComparator);
}
bool
StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring)
{
nsACString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, 0, sub_len).Equals(aSubstring);
}
bool
StringBeginsWith(const nsACString& aSource, const nsACString& aSubstring,
const nsCStringComparator& aComparator)
{
nsACString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, 0, sub_len).Equals(aSubstring, aComparator);
}
bool
StringEndsWith(const nsAString& aSource, const nsAString& aSubstring)
{
nsAString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring);
}
bool
StringEndsWith(const nsAString& aSource, const nsAString& aSubstring,
const nsStringComparator& aComparator)
{
nsAString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring,
aComparator);
}
bool
StringEndsWith(const nsACString& aSource, const nsACString& aSubstring)
{
nsACString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring);
}
bool
StringEndsWith(const nsACString& aSource, const nsACString& aSubstring,
const nsCStringComparator& aComparator)
{
nsACString::size_type src_len = aSource.Length(),
sub_len = aSubstring.Length();
if (sub_len > src_len) {
return false;
}
return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring,
aComparator);
}
static const char16_t empty_buffer[1] = { '\0' };
const nsString&
EmptyString()
{
static const nsDependentString sEmpty(empty_buffer);
return sEmpty;
}
const nsCString&
EmptyCString()
{
static const nsDependentCString sEmpty((const char*)empty_buffer);
return sEmpty;
}
const nsString&
NullString()
{
static const nsXPIDLString sNull;
return sNull;
}
const nsCString&
NullCString()
{
static const nsXPIDLCString sNull;
return sNull;
}
int32_t
CompareUTF8toUTF16(const nsACString& aUTF8String,
const nsAString& aUTF16String)
{
static const uint32_t NOT_ASCII = uint32_t(~0x7F);
const char* u8;
const char* u8end;
aUTF8String.BeginReading(u8);
aUTF8String.EndReading(u8end);
const char16_t* u16;
const char16_t* u16end;
aUTF16String.BeginReading(u16);
aUTF16String.EndReading(u16end);
while (u8 != u8end && u16 != u16end) {
// Cast away the signedness of *u8 to prevent signextension when
// converting to uint32_t
uint32_t c8_32 = (uint8_t)*u8;
if (c8_32 & NOT_ASCII) {
bool err;
c8_32 = UTF8CharEnumerator::NextChar(&u8, u8end, &err);
if (err) {
return INT32_MIN;
}
uint32_t c16_32 = UTF16CharEnumerator::NextChar(&u16, u16end);
// The above UTF16CharEnumerator::NextChar() calls can
// fail, but if it does for anything other than no data to
// look at (which can't happen here), it returns the
// Unicode replacement character 0xFFFD for the invalid
// data they were fed. Ignore that error and treat invalid
// UTF16 as 0xFFFD.
//
// This matches what our UTF16 to UTF8 conversion code
// does, and thus a UTF8 string that came from an invalid
// UTF16 string will compare equal to the invalid UTF16
// string it came from. Same is true for any other UTF16
// string differs only in the invalid part of the string.
if (c8_32 != c16_32) {
return c8_32 < c16_32 ? -1 : 1;
}
} else {
if (c8_32 != *u16) {
return c8_32 > *u16 ? 1 : -1;
}
++u8;
++u16;
}
}
if (u8 != u8end) {
// We get to the end of the UTF16 string, but no to the end of
// the UTF8 string. The UTF8 string is longer than the UTF16
// string
return 1;
}
if (u16 != u16end) {
// We get to the end of the UTF8 string, but no to the end of
// the UTF16 string. The UTF16 string is longer than the UTF8
// string
return -1;
}
// The two strings match.
return 0;
}
void
AppendUCS4ToUTF16(const uint32_t aSource, nsAString& aDest)
{
NS_ASSERTION(IS_VALID_CHAR(aSource), "Invalid UCS4 char");
if (IS_IN_BMP(aSource)) {
aDest.Append(char16_t(aSource));
} else {
aDest.Append(H_SURROGATE(aSource));
aDest.Append(L_SURROGATE(aSource));
}
}
extern "C" {
void Gecko_AppendUTF16toCString(nsACString* aThis, const nsAString* aOther)
{
AppendUTF16toUTF8(*aOther, *aThis);
}
void Gecko_AppendUTF8toString(nsAString* aThis, const nsACString* aOther)
{
AppendUTF8toUTF16(*aOther, *aThis);
}
bool Gecko_FallibleAppendUTF16toCString(nsACString* aThis, const nsAString* aOther)
{
return AppendUTF16toUTF8(*aOther, *aThis, mozilla::fallible);
}
bool Gecko_FallibleAppendUTF8toString(nsAString* aThis, const nsACString* aOther)
{
return AppendUTF8toUTF16(*aOther, *aThis, mozilla::fallible);
}
}
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