Add string pools to save storage.

core/fxcrt/include/fx_string.h

Index: core/fxcrt/include/fx_string.h
diff --git a/core/fxcrt/include/fx_string.h b/core/fxcrt/include/fx_string.h
index c1bd82dd7470367cd812cae61215cdedfe7f503a..82f07259f539db53a9cb1328883aba4737f09b9c 100644
--- a/core/fxcrt/include/fx_string.h
+++ b/core/fxcrt/include/fx_string.h
@@ -8,7 +8,9 @@
 #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"
@@ -170,7 +172,9 @@ class CFX_ByteString {
   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) {
@@ -365,7 +369,9 @@ class CFX_WideString {
   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,
@@ -440,4 +446,28 @@ inline FX_FLOAT FX_atof(const CFX_WideStringC& wsStr) {
 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_