Various changes to JBig2 cache:

core/src/fxcodec/jbig2/JBig2_Context.h

 // 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
 
 #ifndef CORE_SRC_FXCODEC_JBIG2_JBIG2_CONTEXT_H_
 #define CORE_SRC_FXCODEC_JBIG2_JBIG2_CONTEXT_H_
 
 #include <list>
 #include <utility>
 
 #include "../../../../third_party/base/nonstd_unique_ptr.h"
+#include "../../../include/fpdfapi/fpdf_objects.h"
 #include "../../../include/fxcodec/fx_codec_def.h"
 #include "JBig2_List.h"
 #include "JBig2_Page.h"
 #include "JBig2_Segment.h"
 
 class CJBig2_GRDProc;
 class IFX_Pause;
 
-using CJBig2_CachePair = std::pair<const uint8_t*, CJBig2_SymbolDict*>;
+// Cache is keyed by the ObjNum of a stream and an index within the stream.
+using CJBig2_CacheKey = std::pair<FX_DWORD, FX_DWORD>;
+// NB: CJBig2_SymbolDict* is owned.
+using CJBig2_CachePair = std::pair<CJBig2_CacheKey, CJBig2_SymbolDict*>;
 
 #define JBIG2_SUCCESS 0
 #define JBIG2_FAILED -1
 #define JBIG2_ERROR_TOO_SHORT -2
 #define JBIG2_ERROR_FATAL -3
 #define JBIG2_END_OF_PAGE 2
 #define JBIG2_END_OF_FILE 3
 #define JBIG2_ERROR_FILE_FORMAT -4
 #define JBIG2_ERROR_STREAM_TYPE -5
 #define JBIG2_ERROR_LIMIT -6
 #define JBIG2_MIN_SEGMENT_SIZE 11
 
 class CJBig2_Context {
  public:
   static CJBig2_Context* CreateContext(
-      const uint8_t* pGlobalData,
-      FX_DWORD dwGlobalLength,
-      const uint8_t* pData,
-      FX_DWORD dwLength,
+      CPDF_StreamAcc* pGlobalStream,
+      CPDF_StreamAcc* pSrcStream,
       std::list<CJBig2_CachePair>* pSymbolDictCache,
       IFX_Pause* pPause = NULL);
 
   static void DestroyContext(CJBig2_Context* pContext);
 
   int32_t getFirstPage(uint8_t* pBuf,
                        int32_t width,
                        int32_t height,
                        int32_t stride,
                        IFX_Pause* pPause);
 
   int32_t Continue(IFX_Pause* pPause);
   FXCODEC_STATUS GetProcessingStatus() { return m_ProcessingStatus; }
 
  private:
-  CJBig2_Context(const uint8_t* pGlobalData,
-                 FX_DWORD dwGlobalLength,
-                 const uint8_t* pData,
-                 FX_DWORD dwLength,
+  CJBig2_Context(CPDF_StreamAcc* pGlobalStream,
+                 CPDF_StreamAcc* pSrcStream,
                  std::list<CJBig2_CachePair>* pSymbolDictCache,
-                 IFX_Pause* pPause);
+                 IFX_Pause* pPause,
+                 bool bIsGlobal);
 
   ~CJBig2_Context();
 
   int32_t decode_SquentialOrgnazation(IFX_Pause* pPause);
 
   int32_t decode_EmbedOrgnazation(IFX_Pause* pPause);
 
   int32_t decode_RandomOrgnazation_FirstPage(IFX_Pause* pPause);
 
   int32_t decode_RandomOrgnazation(IFX_Pause* pPause);
@@ skipping 45 matching lines @@
   int32_t m_PauseStep;
   IFX_Pause* m_pPause;
   FXCODEC_STATUS m_ProcessingStatus;
   nonstd::unique_ptr<CJBig2_ArithDecoder> m_pArithDecoder;
   nonstd::unique_ptr<CJBig2_GRDProc> m_pGRD;
   JBig2ArithCtx* m_gbContext;
   nonstd::unique_ptr<CJBig2_Segment> m_pSegment;
   FX_DWORD m_dwOffset;
   JBig2RegionInfo m_ri;
   std::list<CJBig2_CachePair>* const m_pSymbolDictCache;
+  bool m_bIsGlobal;
 };
 
 #endif  // CORE_SRC_FXCODEC_JBIG2_JBIG2_CONTEXT_H_