From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- dom/base/nsTextFragment.cpp | 470 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 470 insertions(+) create mode 100644 dom/base/nsTextFragment.cpp (limited to 'dom/base/nsTextFragment.cpp') diff --git a/dom/base/nsTextFragment.cpp b/dom/base/nsTextFragment.cpp new file mode 100644 index 000000000..260e254be --- /dev/null +++ b/dom/base/nsTextFragment.cpp @@ -0,0 +1,470 @@ +/* -*- 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/. */ + +/* + * A class which represents a fragment of text (eg inside a text + * node); if only codepoints below 256 are used, the text is stored as + * a char*; otherwise the text is stored as a char16_t* + */ + +#include "nsTextFragment.h" +#include "nsCRT.h" +#include "nsReadableUtils.h" +#include "nsMemory.h" +#include "nsBidiUtils.h" +#include "nsUnicharUtils.h" +#include "nsUTF8Utils.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/SSE.h" +#include "nsTextFragmentImpl.h" +#include + +#define TEXTFRAG_WHITE_AFTER_NEWLINE 50 +#define TEXTFRAG_MAX_NEWLINES 7 + +// Static buffer used for common fragments +static char* sSpaceSharedString[TEXTFRAG_MAX_NEWLINES + 1]; +static char* sTabSharedString[TEXTFRAG_MAX_NEWLINES + 1]; +static char sSingleCharSharedString[256]; + +using mozilla::CheckedUint32; + +// static +nsresult +nsTextFragment::Init() +{ + // Create whitespace strings + uint32_t i; + for (i = 0; i <= TEXTFRAG_MAX_NEWLINES; ++i) { + sSpaceSharedString[i] = new char[1 + i + TEXTFRAG_WHITE_AFTER_NEWLINE]; + sTabSharedString[i] = new char[1 + i + TEXTFRAG_WHITE_AFTER_NEWLINE]; + sSpaceSharedString[i][0] = ' '; + sTabSharedString[i][0] = ' '; + uint32_t j; + for (j = 1; j < 1 + i; ++j) { + sSpaceSharedString[i][j] = '\n'; + sTabSharedString[i][j] = '\n'; + } + for (; j < (1 + i + TEXTFRAG_WHITE_AFTER_NEWLINE); ++j) { + sSpaceSharedString[i][j] = ' '; + sTabSharedString[i][j] = '\t'; + } + } + + // Create single-char strings + for (i = 0; i < 256; ++i) { + sSingleCharSharedString[i] = i; + } + + return NS_OK; +} + +// static +void +nsTextFragment::Shutdown() +{ + uint32_t i; + for (i = 0; i <= TEXTFRAG_MAX_NEWLINES; ++i) { + delete [] sSpaceSharedString[i]; + delete [] sTabSharedString[i]; + sSpaceSharedString[i] = nullptr; + sTabSharedString[i] = nullptr; + } +} + +nsTextFragment::~nsTextFragment() +{ + ReleaseText(); + MOZ_COUNT_DTOR(nsTextFragment); +} + +void +nsTextFragment::ReleaseText() +{ + if (mState.mLength && m1b && mState.mInHeap) { + free(m2b); // m1b == m2b as far as free is concerned + } + + m1b = nullptr; + mState.mIsBidi = false; + + // Set mState.mIs2b, mState.mInHeap, and mState.mLength = 0 with mAllBits; + mAllBits = 0; +} + +nsTextFragment& +nsTextFragment::operator=(const nsTextFragment& aOther) +{ + ReleaseText(); + + if (aOther.mState.mLength) { + if (!aOther.mState.mInHeap) { + m1b = aOther.m1b; // This will work even if aOther is using m2b + } + else { + CheckedUint32 m2bSize = aOther.mState.mLength; + m2bSize *= (aOther.mState.mIs2b ? sizeof(char16_t) : sizeof(char)); + m2b = nullptr; + if (m2bSize.isValid()) { + m2b = static_cast(malloc(m2bSize.value())); + } + + if (m2b) { + memcpy(m2b, aOther.m2b, m2bSize.value()); + } else { + // allocate a buffer for a single REPLACEMENT CHARACTER + m2b = static_cast(moz_xmalloc(sizeof(char16_t))); + m2b[0] = 0xFFFD; // REPLACEMENT CHARACTER + mState.mIs2b = true; + mState.mInHeap = true; + mState.mLength = 1; + } + } + + if (m1b) { + mAllBits = aOther.mAllBits; + } + } + + return *this; +} + +static inline int32_t +FirstNon8BitUnvectorized(const char16_t *str, const char16_t *end) +{ + typedef Non8BitParameters p; + const size_t mask = p::mask(); + const uint32_t alignMask = p::alignMask(); + const uint32_t numUnicharsPerWord = p::numUnicharsPerWord(); + const int32_t len = end - str; + int32_t i = 0; + + // Align ourselves to a word boundary. + int32_t alignLen = + std::min(len, int32_t(((-NS_PTR_TO_INT32(str)) & alignMask) / sizeof(char16_t))); + for (; i < alignLen; i++) { + if (str[i] > 255) + return i; + } + + // Check one word at a time. + const int32_t wordWalkEnd = ((len - i) / numUnicharsPerWord) * numUnicharsPerWord; + for (; i < wordWalkEnd; i += numUnicharsPerWord) { + const size_t word = *reinterpret_cast(str + i); + if (word & mask) + return i; + } + + // Take care of the remainder one character at a time. + for (; i < len; i++) { + if (str[i] > 255) + return i; + } + + return -1; +} + +#ifdef MOZILLA_MAY_SUPPORT_SSE2 +namespace mozilla { + namespace SSE2 { + int32_t FirstNon8Bit(const char16_t *str, const char16_t *end); + } // namespace SSE2 +} // namespace mozilla +#endif + +/* + * This function returns -1 if all characters in str are 8 bit characters. + * Otherwise, it returns a value less than or equal to the index of the first + * non-8bit character in str. For example, if first non-8bit character is at + * position 25, it may return 25, or for example 24, or 16. But it guarantees + * there is no non-8bit character before returned value. + */ +static inline int32_t +FirstNon8Bit(const char16_t *str, const char16_t *end) +{ +#ifdef MOZILLA_MAY_SUPPORT_SSE2 + if (mozilla::supports_sse2()) { + return mozilla::SSE2::FirstNon8Bit(str, end); + } +#endif + + return FirstNon8BitUnvectorized(str, end); +} + +bool +nsTextFragment::SetTo(const char16_t* aBuffer, int32_t aLength, bool aUpdateBidi) +{ + ReleaseText(); + + if (aLength == 0) { + return true; + } + + char16_t firstChar = *aBuffer; + if (aLength == 1 && firstChar < 256) { + m1b = sSingleCharSharedString + firstChar; + mState.mInHeap = false; + mState.mIs2b = false; + mState.mLength = 1; + + return true; + } + + const char16_t *ucp = aBuffer; + const char16_t *uend = aBuffer + aLength; + + // Check if we can use a shared string + if (aLength <= 1 + TEXTFRAG_WHITE_AFTER_NEWLINE + TEXTFRAG_MAX_NEWLINES && + (firstChar == ' ' || firstChar == '\n' || firstChar == '\t')) { + if (firstChar == ' ') { + ++ucp; + } + + const char16_t* start = ucp; + while (ucp < uend && *ucp == '\n') { + ++ucp; + } + const char16_t* endNewLine = ucp; + + char16_t space = ucp < uend && *ucp == '\t' ? '\t' : ' '; + while (ucp < uend && *ucp == space) { + ++ucp; + } + + if (ucp == uend && + endNewLine - start <= TEXTFRAG_MAX_NEWLINES && + ucp - endNewLine <= TEXTFRAG_WHITE_AFTER_NEWLINE) { + char** strings = space == ' ' ? sSpaceSharedString : sTabSharedString; + m1b = strings[endNewLine - start]; + + // If we didn't find a space in the beginning, skip it now. + if (firstChar != ' ') { + ++m1b; + } + + mState.mInHeap = false; + mState.mIs2b = false; + mState.mLength = aLength; + + return true; + } + } + + // See if we need to store the data in ucs2 or not + int32_t first16bit = FirstNon8Bit(ucp, uend); + + if (first16bit != -1) { // aBuffer contains no non-8bit character + // Use ucs2 storage because we have to + CheckedUint32 m2bSize = aLength; + m2bSize *= sizeof(char16_t); + if (!m2bSize.isValid()) { + return false; + } + + m2b = static_cast(malloc(m2bSize.value())); + if (!m2b) { + return false; + } + memcpy(m2b, aBuffer, m2bSize.value()); + + mState.mIs2b = true; + if (aUpdateBidi) { + UpdateBidiFlag(aBuffer + first16bit, aLength - first16bit); + } + + } else { + // Use 1 byte storage because we can + char* buff = static_cast(malloc(aLength)); + if (!buff) { + return false; + } + + // Copy data + LossyConvertEncoding16to8 converter(buff); + copy_string(aBuffer, aBuffer+aLength, converter); + m1b = buff; + mState.mIs2b = false; + } + + // Setup our fields + mState.mInHeap = true; + mState.mLength = aLength; + + return true; +} + +void +nsTextFragment::CopyTo(char16_t *aDest, int32_t aOffset, int32_t aCount) +{ + NS_ASSERTION(aOffset >= 0, "Bad offset passed to nsTextFragment::CopyTo()!"); + NS_ASSERTION(aCount >= 0, "Bad count passed to nsTextFragment::CopyTo()!"); + + if (aOffset < 0) { + aOffset = 0; + } + + if (uint32_t(aOffset + aCount) > GetLength()) { + aCount = mState.mLength - aOffset; + } + + if (aCount != 0) { + if (mState.mIs2b) { + memcpy(aDest, m2b + aOffset, sizeof(char16_t) * aCount); + } else { + const char *cp = m1b + aOffset; + const char *end = cp + aCount; + LossyConvertEncoding8to16 converter(aDest); + copy_string(cp, end, converter); + } + } +} + +bool +nsTextFragment::Append(const char16_t* aBuffer, uint32_t aLength, bool aUpdateBidi) +{ + // This is a common case because some callsites create a textnode + // with a value by creating the node and then calling AppendData. + if (mState.mLength == 0) { + return SetTo(aBuffer, aLength, aUpdateBidi); + } + + // Should we optimize for aData.Length() == 0? + + CheckedUint32 length = mState.mLength; + length += aLength; + + if (!length.isValid()) { + return false; + } + + if (mState.mIs2b) { + length *= sizeof(char16_t); + if (!length.isValid()) { + return false; + } + + // Already a 2-byte string so the result will be too + char16_t* buff = static_cast(realloc(m2b, length.value())); + if (!buff) { + return false; + } + + memcpy(buff + mState.mLength, aBuffer, aLength * sizeof(char16_t)); + mState.mLength += aLength; + m2b = buff; + + if (aUpdateBidi) { + UpdateBidiFlag(aBuffer, aLength); + } + + return true; + } + + // Current string is a 1-byte string, check if the new data fits in one byte too. + int32_t first16bit = FirstNon8Bit(aBuffer, aBuffer + aLength); + + if (first16bit != -1) { // aBuffer contains no non-8bit character + length *= sizeof(char16_t); + if (!length.isValid()) { + return false; + } + + // The old data was 1-byte, but the new is not so we have to expand it + // all to 2-byte + char16_t* buff = static_cast(malloc(length.value())); + if (!buff) { + return false; + } + + // Copy data into buff + LossyConvertEncoding8to16 converter(buff); + copy_string(m1b, m1b+mState.mLength, converter); + + memcpy(buff + mState.mLength, aBuffer, aLength * sizeof(char16_t)); + mState.mLength += aLength; + mState.mIs2b = true; + + if (mState.mInHeap) { + free(m2b); + } + m2b = buff; + + mState.mInHeap = true; + + if (aUpdateBidi) { + UpdateBidiFlag(aBuffer + first16bit, aLength - first16bit); + } + + return true; + } + + // The new and the old data is all 1-byte + char* buff; + if (mState.mInHeap) { + buff = static_cast(realloc(const_cast(m1b), length.value())); + if (!buff) { + return false; + } + } + else { + buff = static_cast(malloc(length.value())); + if (!buff) { + return false; + } + + memcpy(buff, m1b, mState.mLength); + mState.mInHeap = true; + } + + // Copy aBuffer into buff. + LossyConvertEncoding16to8 converter(buff + mState.mLength); + copy_string(aBuffer, aBuffer + aLength, converter); + + m1b = buff; + mState.mLength += aLength; + + return true; +} + +/* virtual */ size_t +nsTextFragment::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const +{ + if (Is2b()) { + return aMallocSizeOf(m2b); + } + + if (mState.mInHeap) { + return aMallocSizeOf(m1b); + } + + return 0; +} + +// To save time we only do this when we really want to know, not during +// every allocation +void +nsTextFragment::UpdateBidiFlag(const char16_t* aBuffer, uint32_t aLength) +{ + if (mState.mIs2b && !mState.mIsBidi) { + const char16_t* cp = aBuffer; + const char16_t* end = cp + aLength; + while (cp < end) { + char16_t ch1 = *cp++; + uint32_t utf32Char = ch1; + if (NS_IS_HIGH_SURROGATE(ch1) && + cp < end && + NS_IS_LOW_SURROGATE(*cp)) { + char16_t ch2 = *cp++; + utf32Char = SURROGATE_TO_UCS4(ch1, ch2); + } + if (UTF32_CHAR_IS_BIDI(utf32Char) || IsBidiControlRTL(utf32Char)) { + mState.mIsBidi = true; + break; + } + } + } +} -- cgit v1.2.3