Use smart pointers for various Jbig2 decoding contexts

core/fxcodec/jbig2/JBig2_Context.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fxcodec/jbig2/JBig2_Context.h"
 
 #include <algorithm>
 #include <list>
@@ skipping 27 matching lines @@
 
 // Implement a very small least recently used (LRU) cache. It is very
 // common for a JBIG2 dictionary to span multiple pages in a PDF file,
 // and we do not want to decode the same dictionary over and over
 // again. We key off of the memory location of the dictionary. The
 // list keeps track of the freshness of entries, with freshest ones
 // at the front. Even a tiny cache size like 2 makes a dramatic
 // difference for typical JBIG2 documents.
 static const int kSymbolDictCacheMaxSize = 2;
 
-CJBig2_Context* CJBig2_Context::CreateContext(
-    CPDF_StreamAcc* pGlobalStream,
-    CPDF_StreamAcc* pSrcStream,
-    std::list<CJBig2_CachePair>* pSymbolDictCache,
-    IFX_Pause* pPause) {
-  return new CJBig2_Context(pGlobalStream, pSrcStream, pSymbolDictCache, pPause,
-                            false);
-}
-
-void CJBig2_Context::DestroyContext(CJBig2_Context* pContext) {
-  delete pContext;
-}
-
 CJBig2_Context::CJBig2_Context(CPDF_StreamAcc* pGlobalStream,
                                CPDF_StreamAcc* pSrcStream,
                                std::list<CJBig2_CachePair>* pSymbolDictCache,
                                IFX_Pause* pPause,
                                bool bIsGlobal)
     : m_nSegmentDecoded(0),
       m_bInPage(false),
       m_bBufSpecified(false),
       m_PauseStep(10),
       m_pPause(pPause),
       m_ProcessingStatus(FXCODEC_STATUS_FRAME_READY),
-      m_gbContext(nullptr),
       m_dwOffset(0),
       m_pSymbolDictCache(pSymbolDictCache),
       m_bIsGlobal(bIsGlobal) {
   if (pGlobalStream && (pGlobalStream->GetSize() > 0)) {
-    m_pGlobalContext = new CJBig2_Context(nullptr, pGlobalStream,
-                                          pSymbolDictCache, pPause, true);
-  } else {
-    m_pGlobalContext = nullptr;
+    m_pGlobalContext.reset(new CJBig2_Context(nullptr, pGlobalStream,
+                                              pSymbolDictCache, pPause, true));
   }
-
   m_pStream.reset(new CJBig2_BitStream(pSrcStream));
 }
 
-CJBig2_Context::~CJBig2_Context() {
-  FX_Free(m_gbContext);
-  m_gbContext = nullptr;
-  delete m_pGlobalContext;
-  m_pGlobalContext = nullptr;
-}
+CJBig2_Context::~CJBig2_Context() {}
 
 int32_t CJBig2_Context::decode_SquentialOrgnazation(IFX_Pause* pPause) {
   int32_t nRet;
   if (m_pStream->getByteLeft() <= 0)
     return JBIG2_END_OF_FILE;
 
   while (m_pStream->getByteLeft() >= JBIG2_MIN_SEGMENT_SIZE) {
     if (!m_pSegment) {
       m_pSegment.reset(new CJBig2_Segment);
       nRet = parseSegmentHeader(m_pSegment.get());
@@ skipping 997 matching lines @@
             return JBIG2_ERROR_TOO_SHORT;
           }
         }
       }
     }
     pGRD->USESKIP = 0;
     m_pGRD = std::move(pGRD);
   }
   pSegment->m_nResultType = JBIG2_IMAGE_POINTER;
   if (m_pGRD->MMR == 0) {
-    if (!m_gbContext) {
+    if (!m_gbContext.size()) {

[Lei Zhang, 2016/07/18 23:55:10]

if (m_gbContext.empty())

[Wei Li, 2016/07/19 21:21:29]

Done.

       const size_t size = GetHuffContextSize(m_pGRD->GBTEMPLATE);
-      m_gbContext = FX_Alloc(JBig2ArithCtx, size);
-      JBIG2_memset(m_gbContext, 0, sizeof(JBig2ArithCtx) * size);
+      m_gbContext.resize(size);
     }
     if (!m_pArithDecoder) {
       m_pArithDecoder.reset(new CJBig2_ArithDecoder(m_pStream.get()));
-      m_ProcessingStatus = m_pGRD->Start_decode_Arith(
-          &pSegment->m_Result.im, m_pArithDecoder.get(), m_gbContext, pPause);
+      m_ProcessingStatus = m_pGRD->Start_decode_Arith(&pSegment->m_Result.im,
+                                                      m_pArithDecoder.get(),
+                                                      &m_gbContext[0], pPause);
     } else {
       m_ProcessingStatus = m_pGRD->Continue_decode(pPause);
     }
     if (m_ProcessingStatus == FXCODEC_STATUS_DECODE_TOBECONTINUE) {
       if (pSegment->m_cFlags.s.type != 36) {
         if (!m_bBufSpecified) {
           JBig2PageInfo* pPageInfo = m_PageInfoList.back();
           if ((pPageInfo->m_bIsStriped == 1) &&
               (m_ri.y + m_ri.height > m_pPage->m_nHeight)) {
             m_pPage->expand(m_ri.y + m_ri.height,
                             (pPageInfo->m_cFlags & 4) ? 1 : 0);
           }
         }
         FX_RECT Rect = m_pGRD->GetReplaceRect();
         m_pPage->composeFrom(m_ri.x + Rect.left, m_ri.y + Rect.top,
                              pSegment->m_Result.im,
                              (JBig2ComposeOp)(m_ri.flags & 0x03), &Rect);
       }
       return JBIG2_SUCCESS;
     } else {
       m_pArithDecoder.reset();
-      FX_Free(m_gbContext);
-      m_gbContext = nullptr;
+      m_gbContext.clear();
       if (!pSegment->m_Result.im) {
         m_ProcessingStatus = FXCODEC_STATUS_ERROR;
         m_pGRD.reset();
         return JBIG2_ERROR_FATAL;
       }
       m_pStream->alignByte();
       m_pStream->offset(2);
     }
   } else {
     m_pGRD->Start_decode_MMR(&pSegment->m_Result.im, m_pStream.get(), pPause);
@@ skipping 251 matching lines @@
         SBSYMCODES[CURTEMP].code = CURCODE;
         CURCODE = CURCODE + 1;
       }
       CURTEMP = CURTEMP + 1;
     }
     CURLEN = CURLEN + 1;
   }
   FX_Free(LENCOUNT);
   FX_Free(FIRSTCODE);
 }