Android中匿名共享内存demo

package com.example.serverprocess.memory;

import android.content.Context;
import android.os.MemoryFile;
import android.widget.Toast;

import java.io.InputStream;
import java.io.OutputStream;

/**
 * Android中内存共享实现高性能IO操作，内部通过内存映射实现，内存映射是进程间通信的一种方式，可以实现进程间高性能IO操作
 * Created with Android Studio
 * Author:
 * Date:2017/6/16
 */
public class MemoryFileTest {
    private Context content;
    public MemoryFileTest(Context content) {
        this.content = content;
    }
    public void testFileDescriptor() throws Exception {
        MemoryFile file = new MemoryFile("MemoryFileTest", 1000000);
        byte[] buffer = new byte[testString.length];
        //把testString中的内容写入共享内存，testString开始读取的起点是0，读取的内容写入到共享内存中位于共享内存的起点是2000，testString中需要写入共享内存的长度为testString.length
        file.writeBytes(testString, 0, 2000, testString.length);
        //把共享内存中的内容写入buffer，从共享内存中开始读取的起点是2000，读取的内容写入到buffer的起点是0，共享内存中需要写入buffer的长度为testString.length
        file.readBytes(buffer, 2000, 0, testString.length);
        //比较读取的和写入的每个字节是否一致
        compareBuffers(testString, buffer, testString.length);
        OutputStream os = file.getOutputStream();
        //把testString中的数据写入os流中
        os.write(testString);
        InputStream is = file.getInputStream();
        //标记在当前is中的位置
        is.mark(testString.length);
        buffer = new byte[testString.length];
        //把is中数据读取并写入到buffer中
        is.read(buffer);
        compareBuffers(testString, buffer, testString.length);
        // test mark/reset
        is.reset();
        buffer = new byte[testString.length];
        is.read(buffer);
        compareBuffers(testString, buffer, testString.length);
        file.close();
    }
    private void compareBuffers(byte[] buffer1, byte[] buffer2, int length) throws Exception {
        for (int i = 0; i < length; i++) {
            if (buffer1[i] != buffer2[i]) {
                Toast.makeText(content, "readBytes did not read back what writeBytes wrote", Toast.LENGTH_SHORT).show();
            }
        }
    }
    private static final byte[] testString = new byte[] {
            3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8, 9, 7, 9, 3, 2, 3, 8, 4, 6, 2, 6, 4, 3, 3, 8, 3, 2, 7, 9, 5, 0, 2, 8, 8, 4, 1, 9, 7, 1, 6, 9, 3, 9, 9, 3, 7, 5, 1, 0, 5, 8, 2, 0, 9, 7, 4, 9, 4, 4, 5, 9, 2, 3, 0, 7, 8, 1, 6, 4,
            0, 6, 2, 8, 6, 2, 0, 8, 9, 9, 8, 6, 2, 8, 0, 3, 4, 8, 2, 5, 3, 4, 2, 1, 1, 7, 0, 6, 7, 9, 8, 2, 1, 4, 8, 0, 8, 6, 5, 1, 3, 2, 8, 2, 3, 0, 6, 6, 4, 7, 0, 9, 3, 8, 4, 4, 6, 0, 9, 5, 5, 0, 5, 8, 2, 2, 3, 1, 7, 2,
            5, 3, 5, 9, 4, 0, 8, 1, 2, 8, 4, 8, 1, 1, 1, 7, 4, 5, 0, 2, 8, 4, 1, 0, 2, 7, 0, 1, 9, 3, 8, 5, 2, 1, 1, 0, 5, 5, 5, 9, 6, 4, 4, 6, 2, 2, 9, 4, 8, 9, 5, 4, 9, 3, 0, 3, 8, 1, 9, 6, 4, 4, 2, 8, 8, 1, 0, 9, 7, 5,
            6, 6, 5, 9, 3, 3, 4, 4, 6, 1, 2, 8, 4, 7, 5, 6, 4, 8, 2, 3, 3, 7, 8, 6, 7, 8, 3, 1, 6, 5, 2, 7, 1, 2, 0, 1, 9, 0, 9, 1, 4, 5, 6, 4, 8, 5, 6, 6, 9, 2, 3, 4, 6, 0, 3, 4, 8, 6, 1, 0, 4, 5, 4, 3, 2, 6, 6, 4, 8, 2,
            1, 3, 3, 9, 3, 6, 0, 7, 2, 6, 0, 2, 4, 9, 1, 4, 1, 2, 7, 3, 7, 2, 4, 5, 8, 7, 0, 0, 6, 6, 0, 6, 3, 1, 5, 5, 8, 8, 1, 7, 4, 8, 8, 1, 5, 2, 0, 9, 2, 0, 9, 6, 2, 8, 2, 9, 2, 5, 4, 0, 9, 1, 7, 1, 5, 3, 6, 4, 3, 6,
            7, 8, 9, 2, 5, 9, 0, 3, 6, 0, 0, 1, 1, 3, 3, 0, 5, 3, 0, 5, 4, 8, 8, 2, 0, 4, 6, 6, 5, 2, 1, 3, 8, 4, 1, 4, 6, 9, 5, 1, 9, 4, 1, 5, 1, 1, 6, 0, 9, 4, 3, 3, 0, 5, 7, 2, 7, 0, 3, 6, 5, 7, 5, 9, 5, 9, 1, 9, 5, 3,
            0, 9, 2, 1, 8, 6, 1, 1, 7, 3, 8, 1, 9, 3, 2, 6, 1, 1, 7, 9, 3, 1, 0, 5, 1, 1, 8, 5, 4, 8, 0, 7, 4, 4, 6, 2, 3, 7, 9, 9, 6, 2, 7, 4, 9, 5, 6, 7, 3, 5, 1, 8, 8, 5, 7, 5, 2, 7, 2, 4, 8, 9, 1, 2, 2, 7, 9, 3, 8, 1,
            8, 3, 0, 1, 1, 9, 4, 9, 1, 2, 9, 8, 3, 3, 6, 7, 3, 3, 6, 2, 4, 4, 0, 6, 5, 6, 6, 4, 3, 0, 8, 6, 0, 2, 1, 3, 9, 4, 9, 4, 6, 3, 9, 5, 2, 2, 4, 7, 3, 7, 1, 9, 0, 7, 0, 2, 1, 7, 9, 8, 6, 0, 9, 4, 3, 7, 0, 2, 7, 7,
            0, 5, 3, 9, 2, 1, 7, 1, 7, 6, 2, 9, 3, 1, 7, 6, 7, 5, 2, 3, 8, 4, 6, 7, 4, 8, 1, 8, 4, 6, 7, 6, 6, 9, 4, 0, 5, 1, 3, 2, 0, 0, 0, 5, 6, 8, 1, 2, 7, 1, 4, 5, 2, 6, 3, 5, 6, 0, 8, 2, 7, 7, 8, 5, 7, 7, 1, 3, 4, 2,
            7, 5, 7, 7, 8, 9, 6, 0, 9, 1, 7, 3, 6, 3, 7, 1, 7, 8, 7, 2, 1, 4, 6, 8, 4, 4, 0, 9, 0, 1, 2, 2, 4, 9, 5, 3, 4, 3, 0, 1, 4, 6, 5, 4, 9, 5, 8, 5, 3, 7, 1, 0, 5, 0, 7, 9, 2, 2, 7, 9, 6, 8, 9, 2, 5, 8, 9, 2, 3, 5,
            4, 2, 0, 1, 9, 9, 5, 6, 1, 1, 2, 1, 2, 9, 0, 2, 1, 9, 6, 0, 8, 6, 4, 0, 3, 4, 4, 1, 8, 1, 5, 9, 8, 1, 3, 6, 2, 9, 7, 7, 4, 7, 7, 1, 3, 0, 9, 9, 6, 0, 5, 1, 8, 7, 0, 7, 2, 1, 1, 3, 4, 9, 9, 9, 9, 9, 9, 8, 3, 7,
            2, 9, 7, 8, 0, 4, 9, 9, 5, 1, 0, 5, 9, 7, 3, 1, 7, 3, 2, 8, 1, 6, 0, 9, 6, 3, 1, 8, 5, 9, 5, 0, 2, 4, 4, 5, 9, 4, 5, 5, 3, 4, 6, 9, 0, 8, 3, 0, 2, 6, 4, 2, 5, 2, 2, 3, 0, 8, 2, 5, 3, 3, 4, 4, 6, 8, 5, 0, 3, 5,
            2, 6, 1, 9, 3, 1, 1, 8, 8, 1, 7, 1, 0, 1, 0, 0, 0, 3, 1, 3, 7, 8, 3, 8, 7, 5, 2, 8, 8, 6, 5, 8, 7, 5, 3, 3, 2, 0, 8, 3, 8, 1, 4, 2, 0, 6, 1, 7, 1, 7, 7, 6, 6, 9, 1, 4, 7, 3, 0, 3, 5, 9, 8, 2, 5, 3, 4, 9, 0, 4,
            2, 8, 7, 5, 5, 4, 6, 8, 7, 3, 1, 1, 5, 9, 5, 6, 2, 8, 6, 3, 8, 8, 2, 3, 5, 3, 7, 8, 7, 5, 9, 3, 7, 5, 1, 9, 5, 7, 7, 8, 1, 8, 5, 7, 7, 8, 0, 5, 3, 2, 1, 7, 1, 2, 2, 6, 8, 0, 6, 6, 1, 3, 0, 0, 1, 9, 2, 7, 8, 7,
            6, 6, 1, 1, 1, 9, 5, 9, 0, 9, 2, 1, 6, 4, 2, 0, 1, 9, 8, 9, 3, 8, 0, 9, 5, 2, 5, 7, 2, 0, 1, 0, 6, 5, 4, 8, 5, 8, 6, 3, 2, 7, 8, 8, 6, 5, 9, 3, 6, 1, 5, 3, 3, 8, 1, 8, 2, 7, 9, 6, 8, 2, 3, 0, 3, 0, 1, 9, 5, 2,
            0, 3, 5, 3, 0, 1, 8, 5, 2, 9, 6, 8, 9, 9, 5, 7, 7, 3, 6, 2, 2, 5, 9, 9, 4, 1, 3, 8, 9, 1, 2, 4, 9, 7, 2, 1, 7, 7, 5, 2, 8, 3, 4, 7, 9, 1, 3, 1, 5, 1, 5, 5, 7, 4, 8, 5, 7, 2, 4, 2, 4, 5, 4, 1, 5, 0, 6, 9, 5, 9,
            5, 0, 8, 2, 9, 5, 3, 3, 1};
}
Android中内存共享实现高性能IO操作，内部通过内存映射实现，内存映射是进程间通信的一种方式，可以实现进程间高性能IO操作
 * Created with Android Studio
 * Author:
 * Date:2017/6/16
 */
public class MemoryFileTest {
    private Context content;
    public MemoryFileTest(Context content) {
        this.content = content;
    }
    public void testFileDescriptor() throws Exception {
        MemoryFile file = new MemoryFile("MemoryFileTest", 1000000);
        byte[] buffer = new byte[testString.length];
        //把testString中的内容写入共享内存，testString开始读取的起点是0，读取的内容写入到共享内存中位于共享内存的起点是2000，testString中需要写入共享内存的长度为testString.length
        file.writeBytes(testString, 0, 2000, testString.length);
        //把共享内存中的内容写入buffer，从共享内存中开始读取的起点是2000，读取的内容写入到buffer的起点是0，共享内存中需要写入buffer的长度为testString.length
        file.readBytes(buffer, 2000, 0, testString.length);
        //比较读取的和写入的每个字节是否一致
        compareBuffers(testString, buffer, testString.length);
        OutputStream os = file.getOutputStream();
        //把testString中的数据写入os流中
        os.write(testString);
        InputStream is = file.getInputStream();
        //标记在当前is中的位置
        is.mark(testString.length);
        buffer = new byte[testString.length];
        //把is中数据读取并写入到buffer中
        is.read(buffer);
        compareBuffers(testString, buffer, testString.length);
        // test mark/reset
        is.reset();
        buffer = new byte[testString.length];
        is.read(buffer);
        compareBuffers(testString, buffer, testString.length);
        file.close();
    }
    private void compareBuffers(byte[] buffer1, byte[] buffer2, int length) throws Exception {
        for (int i = 0; i < length; i++) {
            if (buffer1[i] != buffer2[i]) {
                Toast.makeText(content, "readBytes did not read back what writeBytes wrote", Toast.LENGTH_SHORT).show();
            }
        }
    }
    private static final byte[] testString = new byte[] {
            3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8, 9, 7, 9, 3, 2, 3, 8, 4, 6, 2, 6, 4, 3, 3, 8, 3, 2, 7, 9, 5, 0, 2, 8, 8, 4, 1, 9, 7, 1, 6, 9, 3, 9, 9, 3, 7, 5, 1, 0, 5, 8, 2, 0, 9, 7, 4, 9, 4, 4, 5, 9, 2, 3, 0, 7, 8, 1, 6, 4,
            0, 6, 2, 8, 6, 2, 0, 8, 9, 9, 8, 6, 2, 8, 0, 3, 4, 8, 2, 5, 3, 4, 2, 1, 1, 7, 0, 6, 7, 9, 8, 2, 1, 4, 8, 0, 8, 6, 5, 1, 3, 2, 8, 2, 3, 0, 6, 6, 4, 7, 0, 9, 3, 8, 4, 4, 6, 0, 9, 5, 5, 0, 5, 8, 2, 2, 3, 1, 7, 2,
            5, 3, 5, 9, 4, 0, 8, 1, 2, 8, 4, 8, 1, 1, 1, 7, 4, 5, 0, 2, 8, 4, 1, 0, 2, 7, 0, 1, 9, 3, 8, 5, 2, 1, 1, 0, 5, 5, 5, 9, 6, 4, 4, 6, 2, 2, 9, 4, 8, 9, 5, 4, 9, 3, 0, 3, 8, 1, 9, 6, 4, 4, 2, 8, 8, 1, 0, 9, 7, 5,
            6, 6, 5, 9, 3, 3, 4, 4, 6, 1, 2, 8, 4, 7, 5, 6, 4, 8, 2, 3, 3, 7, 8, 6, 7, 8, 3, 1, 6, 5, 2, 7, 1, 2, 0, 1, 9, 0, 9, 1, 4, 5, 6, 4, 8, 5, 6, 6, 9, 2, 3, 4, 6, 0, 3, 4, 8, 6, 1, 0, 4, 5, 4, 3, 2, 6, 6, 4, 8, 2,
            1, 3, 3, 9, 3, 6, 0, 7, 2, 6, 0, 2, 4, 9, 1, 4, 1, 2, 7, 3, 7, 2, 4, 5, 8, 7, 0, 0, 6, 6, 0, 6, 3, 1, 5, 5, 8, 8, 1, 7, 4, 8, 8, 1, 5, 2, 0, 9, 2, 0, 9, 6, 2, 8, 2, 9, 2, 5, 4, 0, 9, 1, 7, 1, 5, 3, 6, 4, 3, 6,
            7, 8, 9, 2, 5, 9, 0, 3, 6, 0, 0, 1, 1, 3, 3, 0, 5, 3, 0, 5, 4, 8, 8, 2, 0, 4, 6, 6, 5, 2, 1, 3, 8, 4, 1, 4, 6, 9, 5, 1, 9, 4, 1, 5, 1, 1, 6, 0, 9, 4, 3, 3, 0, 5, 7, 2, 7, 0, 3, 6, 5, 7, 5, 9, 5, 9, 1, 9, 5, 3,
            0, 9, 2, 1, 8, 6, 1, 1, 7, 3, 8, 1, 9, 3, 2, 6, 1, 1, 7, 9, 3, 1, 0, 5, 1, 1, 8, 5, 4, 8, 0, 7, 4, 4, 6, 2, 3, 7, 9, 9, 6, 2, 7, 4, 9, 5, 6, 7, 3, 5, 1, 8, 8, 5, 7, 5, 2, 7, 2, 4, 8, 9, 1, 2, 2, 7, 9, 3, 8, 1,
            8, 3, 0, 1, 1, 9, 4, 9, 1, 2, 9, 8, 3, 3, 6, 7, 3, 3, 6, 2, 4, 4, 0, 6, 5, 6, 6, 4, 3, 0, 8, 6, 0, 2, 1, 3, 9, 4, 9, 4, 6, 3, 9, 5, 2, 2, 4, 7, 3, 7, 1, 9, 0, 7, 0, 2, 1, 7, 9, 8, 6, 0, 9, 4, 3, 7, 0, 2, 7, 7,
            0, 5, 3, 9, 2, 1, 7, 1, 7, 6, 2, 9, 3, 1, 7, 6, 7, 5, 2, 3, 8, 4, 6, 7, 4, 8, 1, 8, 4, 6, 7, 6, 6, 9, 4, 0, 5, 1, 3, 2, 0, 0, 0, 5, 6, 8, 1, 2, 7, 1, 4, 5, 2, 6, 3, 5, 6, 0, 8, 2, 7, 7, 8, 5, 7, 7, 1, 3, 4, 2,
            7, 5, 7, 7, 8, 9, 6, 0, 9, 1, 7, 3, 6, 3, 7, 1, 7, 8, 7, 2, 1, 4, 6, 8, 4, 4, 0, 9, 0, 1, 2, 2, 4, 9, 5, 3, 4, 3, 0, 1, 4, 6, 5, 4, 9, 5, 8, 5, 3, 7, 1, 0, 5, 0, 7, 9, 2, 2, 7, 9, 6, 8, 9, 2, 5, 8, 9, 2, 3, 5,
            4, 2, 0, 1, 9, 9, 5, 6, 1, 1, 2, 1, 2, 9, 0, 2, 1, 9, 6, 0, 8, 6, 4, 0, 3, 4, 4, 1, 8, 1, 5, 9, 8, 1, 3, 6, 2, 9, 7, 7, 4, 7, 7, 1, 3, 0, 9, 9, 6, 0, 5, 1, 8, 7, 0, 7, 2, 1, 1, 3, 4, 9, 9, 9, 9, 9, 9, 8, 3, 7,
            2, 9, 7, 8, 0, 4, 9, 9, 5, 1, 0, 5, 9, 7, 3, 1, 7, 3, 2, 8, 1, 6, 0, 9, 6, 3, 1, 8, 5, 9, 5, 0, 2, 4, 4, 5, 9, 4, 5, 5, 3, 4, 6, 9, 0, 8, 3, 0, 2, 6, 4, 2, 5, 2, 2, 3, 0, 8, 2, 5, 3, 3, 4, 4, 6, 8, 5, 0, 3, 5,
            2, 6, 1, 9, 3, 1, 1, 8, 8, 1, 7, 1, 0, 1, 0, 0, 0, 3, 1, 3, 7, 8, 3, 8, 7, 5, 2, 8, 8, 6, 5, 8, 7, 5, 3, 3, 2, 0, 8, 3, 8, 1, 4, 2, 0, 6, 1, 7, 1, 7, 7, 6, 6, 9, 1, 4, 7, 3, 0, 3, 5, 9, 8, 2, 5, 3, 4, 9, 0, 4,
            2, 8, 7, 5, 5, 4, 6, 8, 7, 3, 1, 1, 5, 9, 5, 6, 2, 8, 6, 3, 8, 8, 2, 3, 5, 3, 7, 8, 7, 5, 9, 3, 7, 5, 1, 9, 5, 7, 7, 8, 1, 8, 5, 7, 7, 8, 0, 5, 3, 2, 1, 7, 1, 2, 2, 6, 8, 0, 6, 6, 1, 3, 0, 0, 1, 9, 2, 7, 8, 7,
            6, 6, 1, 1, 1, 9, 5, 9, 0, 9, 2, 1, 6, 4, 2, 0, 1, 9, 8, 9, 3, 8, 0, 9, 5, 2, 5, 7, 2, 0, 1, 0, 6, 5, 4, 8, 5, 8, 6, 3, 2, 7, 8, 8, 6, 5, 9, 3, 6, 1, 5, 3, 3, 8, 1, 8, 2, 7, 9, 6, 8, 2, 3, 0, 3, 0, 1, 9, 5, 2,
            0, 3, 5, 3, 0, 1, 8, 5, 2, 9, 6, 8, 9, 9, 5, 7, 7, 3, 6, 2, 2, 5, 9, 9, 4, 1, 3, 8, 9, 1, 2, 4, 9, 7, 2, 1, 7, 7, 5, 2, 8, 3, 4, 7, 9, 1, 3, 1, 5, 1, 5, 5, 7, 4, 8, 5, 7, 2, 4, 2, 4, 5, 4, 1, 5, 0, 6, 9, 5, 9,
            5, 0, 8, 2, 9, 5, 3, 3, 1};
}

 

 

可参考资料：https://blog.youkuaiyun.com/goodlixueyong/article/details/53151959