Introducing MemoryMappedExternalResource for creating an external...

src/v8utils.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 298 matching lines @@
       dest += kStepSize;
       src += kStepSize;
     }
   }
 #endif
   while (dest < limit) {
     *dest++ = static_cast<sinkchar>(*src++);
   }
 }
 
+
+// A resource for using mmapped files to back external strings that are read
+// from files.
+class MemoryMappedExternalResource: public
+    v8::String::ExternalAsciiStringResource {
+ public:
+  explicit MemoryMappedExternalResource(const char* filename);
+  MemoryMappedExternalResource(const char* filename,
+                               bool remove_file_on_cleanup);
+  virtual ~MemoryMappedExternalResource();
+
+  virtual const char* data() const { return data_; }
+  virtual size_t length() const { return length_; }
+
+  bool exists() const { return file_ != NULL; }
+  bool IsEmpty() const { return length_ == 0; }

[mnaganov (inactive), 2011/01/18 10:13:34]

is_empty() -- this is a getter-like operation.

[marklam, 2011/01/18 17:32:47]

Done.

+
+  bool EnsureIsAscii(bool abort_if_failed) const;
+  bool EnsureIsAscii() const { return EnsureIsAscii(true); }
+  bool IsAscii() const { return EnsureIsAscii(false); }
+
+ private:
+  void Init(const char* filename);
+
+  char* filename_;
+  OS::MemoryMappedFile* file_;
+
+  const char* data_;
+  size_t length_;
+  bool remove_file_on_cleanup_;
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_V8UTILS_H_