Add string pools to save storage.

core/fxcrt/include/fx_string.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_FXCRT_INCLUDE_FX_STRING_H_
 #define CORE_FXCRT_INCLUDE_FX_STRING_H_
 
 #include <stdint.h>  // For intptr_t.
+
 #include <algorithm>
+#include <functional>
 
 #include "core/fxcrt/cfx_string_c_template.h"
 #include "core/fxcrt/cfx_string_data_template.h"
 #include "core/fxcrt/include/cfx_retain_ptr.h"
 #include "core/fxcrt/include/fx_memory.h"
 #include "core/fxcrt/include/fx_system.h"
 
 class CFX_ByteString;
 class CFX_WideString;
 
@@ skipping 141 matching lines @@
 
   void ReallocBeforeWrite(FX_STRSIZE nNewLen);
   void AllocBeforeWrite(FX_STRSIZE nNewLen);
   void AllocCopy(CFX_ByteString& dest,
                  FX_STRSIZE nCopyLen,
                  FX_STRSIZE nCopyIndex) const;
   void AssignCopy(const FX_CHAR* pSrcData, FX_STRSIZE nSrcLen);
   void Concat(const FX_CHAR* lpszSrcData, FX_STRSIZE nSrcLen);
 
   CFX_RetainPtr<StringData> m_pData;
+
   friend class fxcrt_ByteStringConcat_Test;
+  friend class fxcrt_ByteStringPool_Test;
 };
 
 inline bool operator==(const char* lhs, const CFX_ByteString& rhs) {
   return rhs == lhs;
 }
 inline bool operator==(const CFX_ByteStringC& lhs, const CFX_ByteString& rhs) {
   return rhs == lhs;
 }
 inline bool operator!=(const char* lhs, const CFX_ByteString& rhs) {
   return rhs != lhs;
@@ skipping 174 matching lines @@
 
   void ReallocBeforeWrite(FX_STRSIZE nLen);
   void AllocBeforeWrite(FX_STRSIZE nLen);
   void AllocCopy(CFX_WideString& dest,
                  FX_STRSIZE nCopyLen,
                  FX_STRSIZE nCopyIndex) const;
   void AssignCopy(const FX_WCHAR* pSrcData, FX_STRSIZE nSrcLen);
   void Concat(const FX_WCHAR* lpszSrcData, FX_STRSIZE nSrcLen);
 
   CFX_RetainPtr<StringData> m_pData;
+
   friend class fxcrt_WideStringConcatInPlace_Test;
+  friend class fxcrt_WideStringPool_Test;
 };
 
 inline CFX_WideString operator+(const CFX_WideStringC& str1,
                                 const CFX_WideStringC& str2) {
   return CFX_WideString(str1, str2);
 }
 inline CFX_WideString operator+(const CFX_WideStringC& str1,
                                 const FX_WCHAR* str2) {
   return CFX_WideString(str1, str2);
 }
@@ skipping 54 matching lines @@
   return FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength());
 }
 
 FX_FLOAT FX_atof(const CFX_ByteStringC& str);
 inline FX_FLOAT FX_atof(const CFX_WideStringC& wsStr) {
   return FX_atof(FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength()).c_str());
 }
 bool FX_atonum(const CFX_ByteStringC& str, void* pData);
 FX_STRSIZE FX_ftoa(FX_FLOAT f, FX_CHAR* buf);
 
+uint32_t FX_HashCode_GetA(const CFX_ByteStringC& str, bool bIgnoreCase);
+uint32_t FX_HashCode_GetW(const CFX_WideStringC& str, bool bIgnoreCase);
+
+namespace std {

[dsinclair, 2016/09/15 20:23:26]

Are we allowed to put things into namespace std?

[Tom Sepez, 2016/09/15 20:51:24]

See https://cs.chromium.org/chromium/src/base/optional.h?rcl=0&l=463 for
precedent.

+
+template <>
+struct hash<CFX_ByteString> {
+  std::size_t operator()(const CFX_ByteString& str) const {
+    return FX_HashCode_GetA(str.AsStringC(), false);
+  }
+};
+
+template <>
+struct hash<CFX_WideString> {
+  std::size_t operator()(const CFX_WideString& str) const {
+    return FX_HashCode_GetW(str.AsStringC(), false);
+  }
+};
+
+}  // namespace std
+
+extern template struct std::hash<CFX_ByteString>;
+extern template struct std::hash<CFX_WideString>;
+
 #endif  // CORE_FXCRT_INCLUDE_FX_STRING_H_