Initial Comit

common/mmap.hpp

@@ -0,0 +1,96 @@
+#ifndef _COMMON_MMAP_HPP_
+#define _COMMON_MMAP_HPP_
+#include <fcntl.h> 
+#include <sys/stat.h> 
+#include <unistd.h> 
+#include <cstring>
+#include <sys/mman.h>
+#include <common/string.hpp>
+
+class MemoryMappedFile
+{
+  public:
+    enum CreationFlags{ReadOnly,ReadWrite};
+    MemoryMappedFile(const String& pathFileName,CreationFlags creationFlags);
+    virtual ~MemoryMappedFile();
+    bool open(const String& pathFileName,CreationFlags creationFlags);
+    bool readLine(String &strLine);
+    char readChar(void);
+    bool eof(void);
+    char peekChar(void);
+    void close(void);
+    bool isOkay(void);
+    off_t tell(void); 
+  private:
+    enum {CarriageReturn=0x0D,LineFeed=0x0A,NullChar=0x00};  
+    enum {BlockSize=65536};
+    bool createMemoryMap(void);
+    int getFileAccessFromFlags(CreationFlags creationFlags)const;
+    int getMemoryMapAccessFromFlags(CreationFlags creationFlags)const;
+
+    int mFD = -1;
+    unsigned long mIndex;
+    off_t mFileLength = -1;
+    char *mlpMappedDataBase = 0;
+    CreationFlags mCreationFlags;
+};
+
+/// @brief 
+/// @param pathFileName 
+/// @param access
+inline 
+MemoryMappedFile::MemoryMappedFile(const String& pathFileName,CreationFlags creationFlags)
+{
+  open(pathFileName, creationFlags);
+}
+
+inline
+MemoryMappedFile::~MemoryMappedFile()
+{
+}
+
+inline
+char MemoryMappedFile::readChar()
+{
+  return mlpMappedDataBase[mIndex++];
+}
+
+inline
+bool MemoryMappedFile::eof()
+{
+  return mIndex<mFileLength?false:true;
+}
+
+inline 
+char MemoryMappedFile::peekChar()
+{
+  return mlpMappedDataBase[mIndex];
+}
+
+inline
+off_t MemoryMappedFile::tell(void)
+{
+  return mIndex;
+} 
+
+inline
+bool MemoryMappedFile::readLine(String &strLine)
+{
+  off_t beginPosition = mIndex;
+  while(mIndex<mFileLength && !(LineFeed==mlpMappedDataBase[mIndex++]));
+  off_t currentPosition = mIndex;
+  if(beginPosition==currentPosition)return false;
+  off_t length = (currentPosition - beginPosition) -1;
+  strLine.reserve(length<<1,0);
+  ::memcpy((char*)strLine,mlpMappedDataBase+beginPosition,length);
+  *((char*)strLine+length)=0;
+  return true;
+}
+
+inline
+bool MemoryMappedFile::isOkay(void)
+{
+    return -1==mFD?false:true;
+}
+
+#endif