LCOV - code coverage report
Current view: directory - content/base/src - nsTextFragment.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 194 135 69.6 %
Date: 2012-06-02 Functions: 12 10 83.3 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2                 : /* ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is Mozilla Communicator client code.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is
      18                 :  * Netscape Communications Corporation.
      19                 :  * Portions created by the Initial Developer are Copyright (C) 1998
      20                 :  * the Initial Developer. All Rights Reserved.
      21                 :  *
      22                 :  * Contributor(s):
      23                 :  *
      24                 :  * Alternatively, the contents of this file may be used under the terms of
      25                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      26                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      27                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      28                 :  * of those above. If you wish to allow use of your version of this file only
      29                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      30                 :  * use your version of this file under the terms of the MPL, indicate your
      31                 :  * decision by deleting the provisions above and replace them with the notice
      32                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      33                 :  * the provisions above, a recipient may use your version of this file under
      34                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      35                 :  *
      36                 :  * ***** END LICENSE BLOCK ***** */
      37                 : 
      38                 : /*
      39                 :  * A class which represents a fragment of text (eg inside a text
      40                 :  * node); if only codepoints below 256 are used, the text is stored as
      41                 :  * a char*; otherwise the text is stored as a PRUnichar*
      42                 :  */
      43                 : 
      44                 : #include "nsTextFragment.h"
      45                 : #include "nsCRT.h"
      46                 : #include "nsReadableUtils.h"
      47                 : #include "nsMemory.h"
      48                 : #include "nsBidiUtils.h"
      49                 : #include "nsUnicharUtils.h"
      50                 : #include "nsUTF8Utils.h"
      51                 : #include "mozilla/SSE.h"
      52                 : 
      53                 : #define TEXTFRAG_WHITE_AFTER_NEWLINE 50
      54                 : #define TEXTFRAG_MAX_NEWLINES 7
      55                 : 
      56                 : // Static buffer used for common fragments
      57                 : static char* sSpaceSharedString[TEXTFRAG_MAX_NEWLINES + 1];
      58                 : static char* sTabSharedString[TEXTFRAG_MAX_NEWLINES + 1];
      59                 : static char sSingleCharSharedString[256];
      60                 : 
      61                 : // static
      62                 : nsresult
      63            1404 : nsTextFragment::Init()
      64                 : {
      65                 :   // Create whitespace strings
      66                 :   PRUint32 i;
      67           12636 :   for (i = 0; i <= TEXTFRAG_MAX_NEWLINES; ++i) {
      68           22464 :     sSpaceSharedString[i] = new char[1 + i + TEXTFRAG_WHITE_AFTER_NEWLINE];
      69           22464 :     sTabSharedString[i] = new char[1 + i + TEXTFRAG_WHITE_AFTER_NEWLINE];
      70           11232 :     NS_ENSURE_TRUE(sSpaceSharedString[i] && sTabSharedString[i],
      71                 :                    NS_ERROR_OUT_OF_MEMORY);
      72           11232 :     sSpaceSharedString[i][0] = ' ';
      73           11232 :     sTabSharedString[i][0] = ' ';
      74                 :     PRUint32 j;
      75           50544 :     for (j = 1; j < 1 + i; ++j) {
      76           39312 :       sSpaceSharedString[i][j] = '\n';
      77           39312 :       sTabSharedString[i][j] = '\n';
      78                 :     }
      79          572832 :     for (; j < (1 + i + TEXTFRAG_WHITE_AFTER_NEWLINE); ++j) {
      80          561600 :       sSpaceSharedString[i][j] = ' ';
      81          561600 :       sTabSharedString[i][j] = '\t';
      82                 :     }
      83                 :   }
      84                 : 
      85                 :   // Create single-char strings
      86          360828 :   for (i = 0; i < 256; ++i) {
      87          359424 :     sSingleCharSharedString[i] = i;
      88                 :   }
      89                 : 
      90            1404 :   return NS_OK;
      91                 : }
      92                 : 
      93                 : // static
      94                 : void
      95            1403 : nsTextFragment::Shutdown()
      96                 : {
      97                 :   PRUint32  i;
      98           12627 :   for (i = 0; i <= TEXTFRAG_MAX_NEWLINES; ++i) {
      99           11224 :     delete [] sSpaceSharedString[i];
     100           11224 :     delete [] sTabSharedString[i];
     101           11224 :     sSpaceSharedString[i] = nsnull;
     102           11224 :     sTabSharedString[i] = nsnull;
     103                 :   }
     104            1403 : }
     105                 : 
     106           74983 : nsTextFragment::~nsTextFragment()
     107                 : {
     108           74983 :   ReleaseText();
     109           74983 :   MOZ_COUNT_DTOR(nsTextFragment);
     110           74983 : }
     111                 : 
     112                 : void
     113          149954 : nsTextFragment::ReleaseText()
     114                 : {
     115          149954 :   if (mState.mLength && m1b && mState.mInHeap) {
     116           16870 :     nsMemory::Free(m2b); // m1b == m2b as far as nsMemory is concerned
     117                 :   }
     118                 : 
     119          149954 :   m1b = nsnull;
     120          149954 :   mState.mIsBidi = false;
     121                 : 
     122                 :   // Set mState.mIs2b, mState.mInHeap, and mState.mLength = 0 with mAllBits;
     123          149954 :   mAllBits = 0;
     124          149954 : }
     125                 : 
     126                 : nsTextFragment&
     127             482 : nsTextFragment::operator=(const nsTextFragment& aOther)
     128                 : {
     129             482 :   ReleaseText();
     130                 : 
     131             482 :   if (aOther.mState.mLength) {
     132             475 :     if (!aOther.mState.mInHeap) {
     133             320 :       m1b = aOther.m1b; // This will work even if aOther is using m2b
     134                 :     }
     135                 :     else {
     136                 :       m2b = static_cast<PRUnichar*>
     137                 :                        (nsMemory::Clone(aOther.m2b, aOther.mState.mLength *
     138             155 :                                     (aOther.mState.mIs2b ? sizeof(PRUnichar) : sizeof(char))));
     139                 :     }
     140                 : 
     141             475 :     if (m1b) {
     142             475 :       mAllBits = aOther.mAllBits;
     143                 :     }
     144                 :   }
     145                 : 
     146             482 :   return *this;
     147                 : }
     148                 : 
     149                 : static inline PRInt32
     150               0 : FirstNon8BitUnvectorized(const PRUnichar *str, const PRUnichar *end)
     151                 : {
     152                 : #if PR_BYTES_PER_WORD == 4
     153               0 :   const size_t mask = 0xff00ff00;
     154               0 :   const PRUint32 alignMask = 0x3;
     155               0 :   const PRUint32 numUnicharsPerWord = 2;
     156                 : #elif PR_BYTES_PER_WORD == 8
     157                 :   const size_t mask = 0xff00ff00ff00ff00;
     158                 :   const PRUint32 alignMask = 0x7;
     159                 :   const PRUint32 numUnicharsPerWord = 4;
     160                 : #else
     161                 : #error Unknown platform!
     162                 : #endif
     163                 : 
     164               0 :   const PRInt32 len = end - str;
     165               0 :   PRInt32 i = 0;
     166                 : 
     167                 :   // Align ourselves to a word boundary.
     168                 :   PRInt32 alignLen =
     169               0 :     NS_MIN(len, PRInt32(((-NS_PTR_TO_INT32(str)) & alignMask) / sizeof(PRUnichar)));
     170               0 :   for (; i < alignLen; i++) {
     171               0 :     if (str[i] > 255)
     172               0 :       return i;
     173                 :   }
     174                 : 
     175                 :   // Check one word at a time.
     176               0 :   const PRInt32 wordWalkEnd = ((len - i) / numUnicharsPerWord) * numUnicharsPerWord;
     177               0 :   for (; i < wordWalkEnd; i += numUnicharsPerWord) {
     178               0 :     const size_t word = *reinterpret_cast<const size_t*>(str + i);
     179               0 :     if (word & mask)
     180               0 :       return i;
     181                 :   }
     182                 : 
     183                 :   // Take care of the remainder one character at a time.
     184               0 :   for (; i < len; i++) {
     185               0 :     if (str[i] > 255)
     186               0 :       return i;
     187                 :   }
     188                 : 
     189               0 :   return -1;
     190                 : }
     191                 : 
     192                 : #ifdef MOZILLA_MAY_SUPPORT_SSE2
     193                 : namespace mozilla {
     194                 :   namespace SSE2 {
     195                 :     PRInt32 FirstNon8Bit(const PRUnichar *str, const PRUnichar *end);
     196                 :   }
     197                 : }
     198                 : #endif
     199                 : 
     200                 : /*
     201                 :  * This function returns -1 if all characters in str are 8 bit characters.
     202                 :  * Otherwise, it returns a value less than or equal to the index of the first
     203                 :  * non-8bit character in str. For example, if first non-8bit character is at
     204                 :  * position 25, it may return 25, or for example 24, or 16. But it guarantees
     205                 :  * there is no non-8bit character before returned value.
     206                 :  */
     207                 : static inline PRInt32
     208           16726 : FirstNon8Bit(const PRUnichar *str, const PRUnichar *end)
     209                 : {
     210                 : #ifdef MOZILLA_MAY_SUPPORT_SSE2
     211           16726 :   if (mozilla::supports_sse2()) {
     212           16726 :     return mozilla::SSE2::FirstNon8Bit(str, end);
     213                 :   }
     214                 : #endif
     215                 : 
     216               0 :   return FirstNon8BitUnvectorized(str, end);
     217                 : }
     218                 : 
     219                 : void
     220           74489 : nsTextFragment::SetTo(const PRUnichar* aBuffer, PRInt32 aLength, bool aUpdateBidi)
     221                 : {
     222           74489 :   ReleaseText();
     223                 : 
     224           74489 :   if (aLength == 0) {
     225              53 :     return;
     226                 :   }
     227                 :   
     228           74436 :   PRUnichar firstChar = *aBuffer;
     229           74436 :   if (aLength == 1 && firstChar < 256) {
     230            4595 :     m1b = sSingleCharSharedString + firstChar;
     231            4595 :     mState.mInHeap = false;
     232            4595 :     mState.mIs2b = false;
     233            4595 :     mState.mLength = 1;
     234                 : 
     235            4595 :     return;
     236                 :   }
     237                 : 
     238           69841 :   const PRUnichar *ucp = aBuffer;
     239           69841 :   const PRUnichar *uend = aBuffer + aLength;
     240                 : 
     241                 :   // Check if we can use a shared string
     242           69841 :   if (aLength <= 1 + TEXTFRAG_WHITE_AFTER_NEWLINE + TEXTFRAG_MAX_NEWLINES &&
     243                 :      (firstChar == ' ' || firstChar == '\n' || firstChar == '\t')) {
     244           55353 :     if (firstChar == ' ') {
     245            2116 :       ++ucp;
     246                 :     }
     247                 : 
     248           55353 :     const PRUnichar* start = ucp;
     249          166222 :     while (ucp < uend && *ucp == '\n') {
     250           55516 :       ++ucp;
     251                 :     }
     252           55353 :     const PRUnichar* endNewLine = ucp;
     253                 : 
     254           55353 :     PRUnichar space = ucp < uend && *ucp == '\t' ? '\t' : ' ';
     255          586587 :     while (ucp < uend && *ucp == space) {
     256          475881 :       ++ucp;
     257                 :     }
     258                 : 
     259           55353 :     if (ucp == uend &&
     260                 :         endNewLine - start <= TEXTFRAG_MAX_NEWLINES &&
     261                 :         ucp - endNewLine <= TEXTFRAG_WHITE_AFTER_NEWLINE) {
     262           53125 :       char** strings = space == ' ' ? sSpaceSharedString : sTabSharedString;
     263           53125 :       m1b = strings[endNewLine - start];
     264                 : 
     265                 :       // If we didn't find a space in the beginning, skip it now.
     266           53125 :       if (firstChar != ' ') {
     267           52711 :         ++m1b;
     268                 :       }
     269                 : 
     270           53125 :       mState.mInHeap = false;
     271           53125 :       mState.mIs2b = false;
     272           53125 :       mState.mLength = aLength;
     273                 : 
     274           53125 :       return;        
     275                 :     }
     276                 :   }
     277                 : 
     278                 :   // See if we need to store the data in ucs2 or not
     279           16716 :   PRInt32 first16bit = FirstNon8Bit(ucp, uend);
     280                 : 
     281           16716 :   if (first16bit != -1) { // aBuffer contains no non-8bit character
     282                 :     // Use ucs2 storage because we have to
     283                 :     m2b = (PRUnichar *)nsMemory::Clone(aBuffer,
     284               6 :                                        aLength * sizeof(PRUnichar));
     285               6 :     if (!m2b) {
     286               0 :       return;
     287                 :     }
     288                 : 
     289               6 :     mState.mIs2b = true;
     290               6 :     if (aUpdateBidi) {
     291               6 :       UpdateBidiFlag(aBuffer + first16bit, aLength - first16bit);
     292                 :     }
     293                 : 
     294                 :   } else {
     295                 :     // Use 1 byte storage because we can
     296           16710 :     char* buff = (char *)nsMemory::Alloc(aLength * sizeof(char));
     297           16710 :     if (!buff) {
     298               0 :       return;
     299                 :     }
     300                 : 
     301                 :     // Copy data
     302           16710 :     LossyConvertEncoding16to8 converter(buff);
     303           16710 :     copy_string(aBuffer, aBuffer+aLength, converter);
     304           16710 :     m1b = buff;
     305           16710 :     mState.mIs2b = false;
     306                 :   }
     307                 : 
     308                 :   // Setup our fields
     309           16716 :   mState.mInHeap = true;
     310           16716 :   mState.mLength = aLength;
     311                 : }
     312                 : 
     313                 : void
     314              20 : nsTextFragment::CopyTo(PRUnichar *aDest, PRInt32 aOffset, PRInt32 aCount)
     315                 : {
     316              20 :   NS_ASSERTION(aOffset >= 0, "Bad offset passed to nsTextFragment::CopyTo()!");
     317              20 :   NS_ASSERTION(aCount >= 0, "Bad count passed to nsTextFragment::CopyTo()!");
     318                 : 
     319              20 :   if (aOffset < 0) {
     320               0 :     aOffset = 0;
     321                 :   }
     322                 : 
     323              20 :   if (PRUint32(aOffset + aCount) > GetLength()) {
     324               0 :     aCount = mState.mLength - aOffset;
     325                 :   }
     326                 : 
     327              20 :   if (aCount != 0) {
     328              20 :     if (mState.mIs2b) {
     329               0 :       memcpy(aDest, m2b + aOffset, sizeof(PRUnichar) * aCount);
     330                 :     } else {
     331              20 :       const char *cp = m1b + aOffset;
     332              20 :       const char *end = cp + aCount;
     333              20 :       LossyConvertEncoding8to16 converter(aDest);
     334              20 :       copy_string(cp, end, converter);
     335                 :     }
     336                 :   }
     337              20 : }
     338                 : 
     339                 : void
     340              10 : nsTextFragment::Append(const PRUnichar* aBuffer, PRUint32 aLength, bool aUpdateBidi)
     341                 : {
     342                 :   // This is a common case because some callsites create a textnode
     343                 :   // with a value by creating the node and then calling AppendData.
     344              10 :   if (mState.mLength == 0) {
     345               0 :     SetTo(aBuffer, aLength, aUpdateBidi);
     346                 : 
     347               0 :     return;
     348                 :   }
     349                 : 
     350                 :   // Should we optimize for aData.Length() == 0?
     351                 : 
     352              10 :   if (mState.mIs2b) {
     353                 :     // Already a 2-byte string so the result will be too
     354               0 :     PRUnichar* buff = (PRUnichar*)nsMemory::Realloc(m2b, (mState.mLength + aLength) * sizeof(PRUnichar));
     355               0 :     if (!buff) {
     356               0 :       return;
     357                 :     }
     358                 : 
     359               0 :     memcpy(buff + mState.mLength, aBuffer, aLength * sizeof(PRUnichar));
     360               0 :     mState.mLength += aLength;
     361               0 :     m2b = buff;
     362                 : 
     363               0 :     if (aUpdateBidi) {
     364               0 :       UpdateBidiFlag(aBuffer, aLength);
     365                 :     }
     366                 : 
     367               0 :     return;
     368                 :   }
     369                 : 
     370                 :   // Current string is a 1-byte string, check if the new data fits in one byte too.
     371              10 :   PRInt32 first16bit = FirstNon8Bit(aBuffer, aBuffer + aLength);
     372                 : 
     373              10 :   if (first16bit != -1) { // aBuffer contains no non-8bit character
     374                 :     // The old data was 1-byte, but the new is not so we have to expand it
     375                 :     // all to 2-byte
     376                 :     PRUnichar* buff = (PRUnichar*)nsMemory::Alloc((mState.mLength + aLength) *
     377               0 :                                                   sizeof(PRUnichar));
     378               0 :     if (!buff) {
     379               0 :       return;
     380                 :     }
     381                 : 
     382                 :     // Copy data into buff
     383               0 :     LossyConvertEncoding8to16 converter(buff);
     384               0 :     copy_string(m1b, m1b+mState.mLength, converter);
     385                 : 
     386               0 :     memcpy(buff + mState.mLength, aBuffer, aLength * sizeof(PRUnichar));
     387               0 :     mState.mLength += aLength;
     388               0 :     mState.mIs2b = true;
     389                 : 
     390               0 :     if (mState.mInHeap) {
     391               0 :       nsMemory::Free(m2b);
     392                 :     }
     393               0 :     m2b = buff;
     394                 : 
     395               0 :     mState.mInHeap = true;
     396                 : 
     397               0 :     if (aUpdateBidi) {
     398               0 :       UpdateBidiFlag(aBuffer + first16bit, aLength - first16bit);
     399                 :     }
     400                 : 
     401               0 :     return;
     402                 :   }
     403                 : 
     404                 :   // The new and the old data is all 1-byte
     405                 :   char* buff;
     406              10 :   if (mState.mInHeap) {
     407                 :     buff = (char*)nsMemory::Realloc(const_cast<char*>(m1b),
     408               9 :                                     (mState.mLength + aLength) * sizeof(char));
     409               9 :     if (!buff) {
     410               0 :       return;
     411                 :     }
     412                 :   }
     413                 :   else {
     414               1 :     buff = (char*)nsMemory::Alloc((mState.mLength + aLength) * sizeof(char));
     415               1 :     if (!buff) {
     416               0 :       return;
     417                 :     }
     418                 : 
     419               1 :     memcpy(buff, m1b, mState.mLength);
     420               1 :     mState.mInHeap = true;
     421                 :   }
     422                 : 
     423                 :   // Copy aBuffer into buff.
     424              10 :   LossyConvertEncoding16to8 converter(buff + mState.mLength);
     425              10 :   copy_string(aBuffer, aBuffer + aLength, converter);
     426                 : 
     427              10 :   m1b = buff;
     428              10 :   mState.mLength += aLength;
     429                 : 
     430                 : }
     431                 : 
     432                 : /* virtual */ size_t
     433               0 : nsTextFragment::SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const
     434                 : {
     435               0 :   if (Is2b()) {
     436               0 :     return aMallocSizeOf(m2b);
     437                 :   }
     438                 : 
     439               0 :   if (mState.mInHeap) {
     440               0 :     return aMallocSizeOf(m1b);
     441                 :   }
     442                 : 
     443               0 :   return 0;
     444                 : }
     445                 : 
     446                 : // To save time we only do this when we really want to know, not during
     447                 : // every allocation
     448                 : void
     449               6 : nsTextFragment::UpdateBidiFlag(const PRUnichar* aBuffer, PRUint32 aLength)
     450                 : {
     451               6 :   if (mState.mIs2b && !mState.mIsBidi) {
     452               6 :     const PRUnichar* cp = aBuffer;
     453               6 :     const PRUnichar* end = cp + aLength;
     454              69 :     while (cp < end) {
     455              61 :       PRUnichar ch1 = *cp++;
     456              61 :       PRUint32 utf32Char = ch1;
     457              61 :       if (NS_IS_HIGH_SURROGATE(ch1) &&
     458                 :           cp < end &&
     459                 :           NS_IS_LOW_SURROGATE(*cp)) {
     460               3 :         PRUnichar ch2 = *cp++;
     461               3 :         utf32Char = SURROGATE_TO_UCS4(ch1, ch2);
     462                 :       }
     463              61 :       if (UTF32_CHAR_IS_BIDI(utf32Char) || IS_BIDI_CONTROL_CHAR(utf32Char)) {
     464               4 :         mState.mIsBidi = true;
     465               4 :         break;
     466                 :       }
     467                 :     }
     468                 :   }
     469               6 : }

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