feature: introduce java sdk

Signed-off-by: Shuoran Liu <shuoranliu@gmail.com>

java/README.md

@@ -0,0 +1,31 @@
+# Usage
+
+### Build shared library
+
+```bash
+cd libsdk
+sh build.sh
+sudo cp libcfs.so /usr/lib/libcfs.so
+```
+
+### Build jar with dependencies
+
+```bash
+cd java
+mvn clean package
+```
+
+### Deploy single-node cluster using docker
+
+```bash
+cd docker
+./run_docker.sh -r
+```
+
+## Run the java test program
+
+```
+java -cp target/libchubaofs-1.0-SNAPSHOT-jar-with-dependencies.jar io.chubao.fs.TestCfsClient ls <dirpath>
+java -cp target/libchubaofs-1.0-SNAPSHOT-jar-with-dependencies.jar io.chubao.fs.TestCfsClient read <filepath>
+java -cp target/libchubaofs-1.0-SNAPSHOT-jar-with-dependencies.jar io.chubao.fs.TestCfsClient write <filepath>
+```

java/pom.xml

@@ -13,6 +13,14 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
+    <dependencies>
+        <dependency>
+            <groupId>net.java.dev.jna</groupId>
+            <artifactId>jna</artifactId>
+            <version>5.6.0</version>
+        </dependency>
+    </dependencies>
+
     <build>
         <resources>
             <resource>
@@ -25,7 +33,32 @@
                 <filtering>false</filtering>
             </resource>
         </resources>
+
         <plugins>
+            <plugin>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>3.3.0</version>
+                <configuration>
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <artifactId>maven-clean-plugin</artifactId>
+                <version>3.1.0</version>
+            </plugin>
+
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
@@ -38,4 +71,4 @@
         </plugins>
     </build>
 
-</project>
+</project>

java/src/main/java/io/chubao/fs/CfsDriver.java

@@ -0,0 +1,94 @@
+package io.chubao.fs;
+
+import com.sun.jna.Library;
+import com.sun.jna.Structure;
+import com.sun.jna.Pointer;
+import java.util.List;
+import java.util.Arrays;
+
+public interface CfsDriver extends Library {
+    public class StatInfo extends Structure implements Structure.ByReference {
+        // note that the field layout should be aligned with cfs_stat_info
+        public long ino;
+        public long size;
+        public long blocks;
+        public long atime;
+        public long mtime;
+        public long ctime;
+        public int atime_nsec;
+        public int mtime_nsec;
+        public int ctime_nsec;
+        public int mode;
+        public int nlink;
+        public int blkSize;
+        public int uid;
+        public int gid;
+
+        public StatInfo() {
+            super();
+        };
+
+        @Override
+        protected List<String> getFieldOrder() {
+            return Arrays.asList(new String[] { "ino", "size", "blocks", "atime", "mtime", "ctime", "atime_nsec",
+                    "mtime_nsec", "ctime_nsec", "mode", "nlink", "blkSize", "uid", "gid" });
+        }
+    }
+
+    public class Dirent extends Structure {
+        // note that the field layout should be aligned with cfs_dirent
+        public long ino;
+        public byte[] name = new byte[256];
+        public byte dType;
+
+        public Dirent() {
+            super();
+        };
+
+        @Override
+        protected List<String> getFieldOrder() {
+            return Arrays.asList(new String[] { "ino", "name", "dType" });
+        }
+    }
+
+    public class DirentArray extends Structure {
+        public static class ByValue extends DirentArray implements Structure.ByValue {
+        }
+
+        // note that the field layout should be aligned with GoSlice
+        public Pointer data;
+        public long len;
+        public long cap;
+
+        public DirentArray() {
+            super();
+        }
+
+        protected List<String> getFieldOrder() {
+            return Arrays.asList(new String[] { "data", "len", "cap" });
+        }
+    }
+
+    // exports from shared library
+    long cfs_new_client();
+
+    int cfs_set_client(long id, String key, String val);
+
+    int cfs_start_client(long id);
+
+    void cfs_close_client(long id);
+
+    int cfs_getattr(long id, String path, StatInfo stat);
+
+    int cfs_open(long id, String path, int flags, int mode);
+
+    int cfs_flush(long id, int fd);
+
+    void cfs_close(long id, int fd);
+
+    long cfs_write(long id, int fd, byte[] buf, long size, long offset);
+
+    long cfs_read(long id, int fd, byte[] buf, long size, long offset);
+
+    int cfs_readdir(long id, int fd, DirentArray.ByValue dents, long count);
+}

java/src/main/java/io/chubao/fs/CfsMount.java

@@ -0,0 +1,88 @@
+package io.chubao.fs;
+
+import com.sun.jna.Native;
+import com.sun.jna.Pointer;
+
+import io.chubao.fs.CfsDriver.Dirent;
+import io.chubao.fs.CfsDriver.DirentArray;
+
+public class CfsMount {
+    public int O_RDONLY = 0;
+    public int O_WRONLY = 1;
+    public int O_RDWR = 2;
+    public int O_ACCMODE = 3;
+    public int O_CREAT = 100;
+    public int O_TRUNC = 1000;
+    public int O_APPEND = 2000;
+    public int O_DIRECT = 40000;
+
+    public int S_IFDIR = 0040000;
+    public int S_IFREG = 0100000;
+    public int S_IFLNK = 0120000;
+
+    private CfsDriver driver;
+    private String libpath;
+
+    public CfsMount(String path) {
+        libpath = path;
+        driver = (CfsDriver) Native.load(libpath, CfsDriver.class);
+    }
+
+    public long NewClient() {
+        return driver.cfs_new_client();
+    }
+
+    public int SetClient(long id, String key, String val) {
+        return driver.cfs_set_client(id, key, val);
+    }
+
+    public int StartClient(long id) {
+        return driver.cfs_start_client(id);
+    }
+
+    public void CloseClient(long id) {
+        driver.cfs_close_client(id);
+    }
+
+    public int GetAttr(long id, String path, CfsDriver.StatInfo stat) {
+        return driver.cfs_getattr(id, path, stat);
+    }
+
+    public int Open(long id, String path, int flags, int mode) {
+        return driver.cfs_open(id, path, flags, mode);
+    }
+
+    public void Close(long id, int fd) {
+        driver.cfs_close(id, fd);
+    }
+
+    public long Write(long id, int fd, byte[] buf, long size, long offset) {
+        return driver.cfs_write(id, fd, buf, size, offset);
+    }
+
+    public long Read(long id, int fd, byte[] buf, long size, long offset) {
+        return driver.cfs_read(id, fd, buf, size, offset);
+    }
+
+    /*
+     * Note that the memory allocated for Dirent[] must be countinuous. For example,
+     * (new Dirent()).toArray(count).
+     */
+    public int Readdir(long id, int fd, Dirent[] dents, int count) {
+        Pointer arr = dents[0].getPointer();
+        DirentArray.ByValue slice = new DirentArray.ByValue();
+        slice.data = arr;
+        slice.len = (long) count;
+        slice.cap = (long) count;
+
+        long arrSize = driver.cfs_readdir(id, fd, slice, count);
+
+        if (arrSize > 0) {
+            for (int i = 0; i < (int) arrSize; i++) {
+                dents[i].read();
+            }
+        }
+
+        return (int) arrSize;
+    }
+}

java/src/main/java/io/chubao/fs/TestCfsClient.java

@@ -0,0 +1,115 @@
+package io.chubao.fs;
+
+import io.chubao.fs.CfsDriver.Dirent;
+
+public class TestCfsClient {
+    public static void main(String[] args) {
+        CfsMount mnt = new CfsMount("/usr/lib/libcfs.so");
+        long cid = mnt.NewClient();
+
+        mnt.SetClient(cid, "volName", "ltptest");
+        mnt.SetClient(cid, "masterAddr", "192.168.0.11:17010,192.168.0.12:17010,192.168.0.13:17010");
+        mnt.SetClient(cid, "logDir", "/home/liushuoran/log");
+        mnt.SetClient(cid, "logLeval", "info");
+        int ret = mnt.StartClient(cid);
+        if (ret < 0) {
+            System.out.println("start client failed!!!");
+            return;
+        }
+
+        if (args.length < 2) {
+            System.out.println("Invalid args: lack of path");
+            return;
+        }
+
+        String targetPath = args[1];
+
+        if (args[0].equals("read")) {
+            CfsDriver.StatInfo stat = new CfsDriver.StatInfo();
+            ret = mnt.GetAttr(cid, targetPath, stat);
+            if (ret < 0) {
+                System.out.println("GetAttr failed: " + ret);
+                return;
+            }
+
+            System.out.println("ino: " + stat.ino);
+            System.out.println("size: " + stat.size);
+            System.out.println("blocks: " + stat.blocks);
+            System.out.println("nlink: " + stat.nlink);
+            System.out.println("mode: " + stat.mode);
+            System.out.println("uid: " + stat.uid);
+            System.out.println("gid: " + stat.gid);
+
+            int fd = mnt.Open(cid, targetPath, mnt.O_RDONLY, 0644);
+
+            if (fd < 0) {
+                System.out.println("Open failed: " + fd);
+                return;
+            }
+
+            byte[] buf = new byte[4096];
+
+            long readByte = mnt.Read(cid, fd, buf, buf.length, 0);
+
+            System.out.println("fd: " + fd);
+            System.out.println("read bytes: " + readByte);
+            System.out.println(new String(buf));
+
+            // verify md5sum
+            byte[] toVerify = new byte[(int) readByte];
+            System.arraycopy(buf, 0, toVerify, 0, (int) readByte);
+
+            StringBuilder sb = new StringBuilder();
+            java.security.MessageDigest md5 = null;
+            try {
+                md5 = java.security.MessageDigest.getInstance("MD5");
+                md5.update(toVerify);
+            } catch (java.security.NoSuchAlgorithmException e) {
+            }
+            if (md5 != null) {
+                for (byte b : md5.digest()) {
+                    sb.append(String.format("%02x", b));
+                }
+            }
+
+            System.out.println("md5: " + sb.toString());
+
+            mnt.Close(cid, fd);
+        } else if (args[0].equals("write")) {
+            int fd = mnt.Open(cid, targetPath, mnt.O_RDWR | mnt.O_CREAT, 0644);
+
+            if (fd < 0) {
+                System.out.println("Open failed: " + fd);
+                return;
+            }
+
+            String toWrite = "abcdefg";
+            byte[] buf = toWrite.getBytes();
+
+            long writeBytes = mnt.Write(cid, fd, buf, buf.length, 0);
+
+            System.out.println("write bytes: " + writeBytes);
+
+            mnt.Close(cid, fd);
+        } else if (args[0].equals("ls")) {
+            int fd = mnt.Open(cid, targetPath, mnt.O_RDWR, 0644);
+
+            if (fd < 0) {
+                System.out.println("Open failed: " + fd);
+                return;
+            }
+
+            Dirent dent = new Dirent();
+            Dirent[] dents = (Dirent[]) dent.toArray(16);
+            int n = mnt.Readdir(cid, fd, dents, 16);
+            System.out.println("num of entries: " + n);
+            for (int i = 0; i < n; i++) {
+                System.out.println("ino: " + dents[i].ino + " | d_type: " + dents[i].dType);
+            }
+
+            mnt.Close(cid, fd);
+        }
+
+        mnt.CloseClient(cid);
+    }
+}

java/src/main/java/io/chubao/fs/package-info.java

@@ -1 +0,0 @@
-package io.chubao.fs;