add MemoryMappedFile definition for cpp

Author: bianhq

.gitignore

@@ -23,4 +23,5 @@ test30G_pixels/
 *.csv
 resources/*.xml
 *.so
+*.o
 .vscode

cpp/Makefile

@@ -1,7 +1,10 @@
-all: NativePixelsCacheReader
+all: PixelsCacheReader
 
-NativePixelsCacheReader:
+PixelsCacheReader: PixelsCacheReader.cc MemoryMappedFile
 	$(CXX) -shared -fPIC $@.cc -o lib_pixels.so -I/usr/lib/jvm/java-1.8.0-openjdk-amd64/include/ -I/usr/lib/jvm/java-8-openjdk-amd64/include/linux/
 
+MemoryMappedFile:
+	$(CXX) -c $@.cc
+
 clean:
-	rm -rf ./lib_pixels.so
+	rm -rf ./lib_pixels.so ./*.o

cpp/MemoryMappedFile.cc

@@ -0,0 +1,2 @@
+#include <iostream>
+#include "MemoryMappedFile.h"

cpp/MemoryMappedFile.h

@@ -0,0 +1,243 @@
+#ifndef MemoryMappedFile_H
+#define MemoryMappedFile_H
+
+#include <string>
+
+using namespace std;
+
+typedef char byte;
+
+class MemoryMappedFile
+{
+private:
+    //Unsafe unsafe;
+    //private static final Method mmap;
+    //Method unmmap;
+    static int BYTE_ARRAY_OFFSET;
+
+    long addr, size;
+    string loc;
+
+    static long roundTo4096(long i)
+    {
+        return (i + 0xfffL) & ~0xfffL;
+    }
+
+    void mapAndSetOffset()
+    {
+    }
+
+public:
+    /**
+     * Constructs a new memory mapped file.
+     *
+     * @param loc the file name
+     * @param len the file length
+     * @throws Exception in case there was an error creating the memory mapped file
+     */
+    MemoryMappedFile(string &loc, long len)
+    {
+        loc = loc;
+        size = roundTo4096(len);
+        mapAndSetOffset();
+    }
+
+    void unmap()
+    {
+    }
+
+    /**
+     * Reads a byte from the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @return the value read
+     */
+    byte getByte(long pos)
+    {
+        return 0;
+    }
+
+    /**
+     * Reads a byte (volatile) from the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @return the value read
+     */
+    byte getByteVolatile(long pos)
+    {
+        return 0;
+    }
+
+    short getShort(long pos)
+    {
+        return 0;
+    }
+
+    short getShortVolatile(long pos)
+    {
+        return 0;
+    }
+
+    /**
+     * Reads an int from the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @return the value read
+     */
+    int getInt(long pos)
+    {
+        return 0;
+    }
+
+    /**
+     * Reads an int (volatile) from the specified position.
+     *
+     * @param pos position in the memory mapped file
+     * @return the value read
+     */
+    int getIntVolatile(long pos)
+    {
+        return 0;
+    }
+
+    /**
+     * Reads a long from the specified position.
+     *
+     * @param pos position in the memory mapped file
+     * @return the value read
+     */
+    long getLong(long pos)
+    {
+        return 0;
+    }
+
+    /**
+     * Reads a long (volatile) from the specified position.
+     *
+     * @param pos position in the memory mapped file
+     * @return the value read
+     */
+    long getLongVolatile(long pos)
+    {
+        return 0;
+    }
+
+    /**
+     * Writes a byte to the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @param val the value to write
+     */
+    void putByte(long pos, byte val)
+    {
+    }
+
+    void putBytes(long pos, byte* val, int length)
+    {
+        for (int i = 0; i < length ; ++i)
+        {
+            
+        }
+    }
+
+    /**
+     * Writes a byte (volatile) to the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @param val the value to write
+     */
+    void putByteVolatile(long pos, byte val)
+    {
+    }
+
+    void putShort(long pos, short val)
+    {
+    }
+
+    void putShortVolatile(long pos, short val)
+    {
+    }
+
+    /**
+     * Writes an int to the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @param val the value to write
+     */
+    void putInt(long pos, int val)
+    {
+    }
+
+    /**
+     * Writes an int (volatile) to the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @param val the value to write
+     */
+    void putIntVolatile(long pos, int val)
+    {
+    }
+
+    /**
+     * Writes a long to the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @param val the value to write
+     */
+    void putLong(long pos, long val)
+    {
+    }
+
+    /**
+     * Writes a long (volatile) to the specified position.
+     *
+     * @param pos the position in the memory mapped file
+     * @param val the value to write
+     */
+    void putLongVolatile(long pos, long val)
+    {
+    }
+
+    /**
+     * Reads a buffer of data.
+     *
+     * @param pos    the position in the memory mapped file
+     * @param data   the input buffer
+     * @param offset the offset in the buffer of the first byte to read data into
+     * @param length the length of the data
+     */
+    void getBytes(long pos, byte* data, int offset, int length)
+    {
+    }
+
+    /**
+     * Writes a buffer of data.
+     *
+     * @param pos    the position in the memory mapped file
+     * @param data   the output buffer
+     * @param offset the offset in the buffer of the first byte to write
+     * @param length the length of the data
+     */
+    void setBytes(long pos, byte* data, int offset, int length)
+    {
+    }
+
+    bool compareAndSwapInt(long pos, int expected, int value)
+    {
+    }
+
+    bool compareAndSwapLong(long pos, long expected, long value)
+    {
+    }
+
+    long getAndAddLong(long pos, long delta)
+    {
+    }
+
+    long getSize()
+    {
+        return size;
+    }
+};
+
+#endif

cpp/NativePixelsCacheReader.cc cpp/PixelsCacheReader.cccpp/NativePixelsCacheReader.cc renamed to cpp/PixelsCacheReader.cc

@@ -1,5 +1,6 @@
 #include <iostream>
-#include "NativePixelsCacheReader.h"
+#include "PixelsCacheReader.h"
+#include "MemoryMappedFile.h"
 using namespace std;
 
 JNIEXPORT jbyteArray JNICALL Java_cn_edu_ruc_iir_pixels_cache_NativePixelsCacheReader_get