Add slice copy support for socket file type.

Splice can be used to speed up file copy operations
by avoiding moving any memory between kernel/user space.
But splice copy can not support from socket file to
regular/socket file directly. So use pipe file as proxy,
socket/regular --> pipe --> socket/regular. Even it needs
2 times splice syscall, it is still much faster
than user space copy.

Please refer to the comparison data below for the time
consumption of executing FileUtils.copy in
FileUtilsTest:testCopy_SocketToFile_FileToSocket

file-->socket(unit ms):
32KB: user_cp:0.604, splice_cp:0.113, reduce 80%
32MB: user_cp:236, splice_cp:68, reduce 71%

socket-->file(unit ms):
32KB: user_cp:0.611, splice_cp:0.240, reduce 61%
32MB: user_cp:284, splice_cp:88, reduce 69%

The network environment for this test is localhost,
and the data in real scenarios depends more
on the actual network environment.

Test: atest FrameworksCoreTests:android.os.FileUtilsTest

Change-Id: I0636647934a889ce95bdf4df0db428cb370148fd
Signed-off-by: lizhigang <lizhigang.1220@bytedance.com>

core/java/android/os/FileUtils.java

@@ -25,6 +25,7 @@ import static android.os.ParcelFileDescriptor.MODE_WRITE_ONLY;
 import static android.system.OsConstants.EINVAL;
 import static android.system.OsConstants.ENOSYS;
 import static android.system.OsConstants.F_OK;
+import static android.system.OsConstants.EIO;
 import static android.system.OsConstants.O_ACCMODE;
 import static android.system.OsConstants.O_APPEND;
 import static android.system.OsConstants.O_CREAT;
@@ -37,6 +38,7 @@ import static android.system.OsConstants.SPLICE_F_MORE;
 import static android.system.OsConstants.SPLICE_F_MOVE;
 import static android.system.OsConstants.S_ISFIFO;
 import static android.system.OsConstants.S_ISREG;
+import static android.system.OsConstants.S_ISSOCK;
 import static android.system.OsConstants.W_OK;
 
 import android.annotation.NonNull;
@@ -459,6 +461,8 @@ public final class FileUtils {
                     }
                 } else if (S_ISFIFO(st_in.st_mode) || S_ISFIFO(st_out.st_mode)) {
                     return copyInternalSplice(in, out, count, signal, executor, listener);
+                } else if (S_ISSOCK(st_in.st_mode) || S_ISSOCK(st_out.st_mode)) {
+                    return copyInternalSpliceSocket(in, out, count, signal, executor, listener);
                 }
             } catch (ErrnoException e) {
                 throw e.rethrowAsIOException();
@@ -509,6 +513,86 @@ public final class FileUtils {
         }
         return progress;
     }
+    /**
+     * Requires one of input or output to be a socket file.
+     *
+     * @hide
+     */
+    @VisibleForTesting
+    public static long copyInternalSpliceSocket(FileDescriptor in, FileDescriptor out, long count,
+            CancellationSignal signal, Executor executor, ProgressListener listener)
+            throws ErrnoException {
+        long progress = 0;
+        long checkpoint = 0;
+        long countToRead = count;
+        long countInPipe = 0;
+        long t;
+
+        FileDescriptor[] pipes = Os.pipe();
+
+        while (countToRead > 0 || countInPipe > 0) {
+            if (countToRead > 0) {
+                t = Os.splice(in, null, pipes[1], null, Math.min(countToRead, COPY_CHECKPOINT_BYTES),
+                              SPLICE_F_MOVE | SPLICE_F_MORE);
+                if (t < 0) {
+                    // splice error
+                    Slog.e(TAG, "splice error, fdIn --> pipe, copy size:" + count +
+                           ", copied:" + progress +
+                           ", read:" + (count - countToRead) +
+                           ", in pipe:" + countInPipe);
+                    break;
+                } else if (t == 0) {
+                    // end of input, input count larger than real size
+                    Slog.w(TAG, "Reached the end of the input file. The size to be copied exceeds the actual size, copy size:" + count +
+                           ", copied:" + progress +
+                           ", read:" + (count - countToRead) +
+                           ", in pipe:" + countInPipe);
+                    countToRead = 0;
+                } else {
+                    countInPipe += t;
+                    countToRead -= t;
+                }
+            }
+
+            if (countInPipe > 0) {
+                t = Os.splice(pipes[0], null, out, null, Math.min(countInPipe, COPY_CHECKPOINT_BYTES),
+                              SPLICE_F_MOVE | SPLICE_F_MORE);
+                // The data is already in the pipeline, so the return value will not be zero.
+                // If it is 0, it means an error has occurred. So here use t<=0.
+                if (t <= 0) {
+                    Slog.e(TAG, "splice error, pipe --> fdOut, copy size:" + count +
+                           ", copied:" + progress +
+                           ", read:" + (count - countToRead) +
+                           ", in pipe: " + countInPipe);
+                    throw new ErrnoException("splice, pipe --> fdOut", EIO);
+                } else {
+                    progress += t;
+                    checkpoint += t;
+                    countInPipe -= t;
+                }
+            }
+
+            if (checkpoint >= COPY_CHECKPOINT_BYTES) {
+                if (signal != null) {
+                    signal.throwIfCanceled();
+                }
+                if (executor != null && listener != null) {
+                    final long progressSnapshot = progress;
+                    executor.execute(() -> {
+                        listener.onProgress(progressSnapshot);
+                    });
+                }
+                checkpoint = 0;
+            }
+        }
+        if (executor != null && listener != null) {
+            final long progressSnapshot = progress;
+            executor.execute(() -> {
+                listener.onProgress(progressSnapshot);
+            });
+        }
+        return progress;
+    }
 
     /**
      * Requires both input and output to be a regular file.

core/tests/coretests/src/android/os/FileUtilsTest.java

@@ -29,6 +29,7 @@ import static android.os.ParcelFileDescriptor.MODE_READ_ONLY;
 import static android.os.ParcelFileDescriptor.MODE_READ_WRITE;
 import static android.os.ParcelFileDescriptor.MODE_TRUNCATE;
 import static android.os.ParcelFileDescriptor.MODE_WRITE_ONLY;
+import static android.system.OsConstants.AF_INET;
 import static android.system.OsConstants.F_OK;
 import static android.system.OsConstants.O_APPEND;
 import static android.system.OsConstants.O_CREAT;
@@ -37,6 +38,7 @@ import static android.system.OsConstants.O_RDWR;
 import static android.system.OsConstants.O_TRUNC;
 import static android.system.OsConstants.O_WRONLY;
 import static android.system.OsConstants.R_OK;
+import static android.system.OsConstants.SOCK_STREAM;
 import static android.system.OsConstants.W_OK;
 import static android.system.OsConstants.X_OK;
 import static android.text.format.DateUtils.DAY_IN_MILLIS;
@@ -54,6 +56,7 @@ import static org.junit.Assert.fail;
 import android.content.Context;
 import android.os.FileUtils.MemoryPipe;
 import android.provider.DocumentsContract.Document;
+import android.system.Os;
 import android.util.DataUnit;
 
 import androidx.test.InstrumentationRegistry;
@@ -70,6 +73,8 @@ import org.junit.runner.RunWith;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileInputStream;
@@ -77,6 +82,7 @@ import java.io.FileOutputStream;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Random;
+import java.net.InetSocketAddress;
 
 @RunWith(AndroidJUnit4.class)
 public class FileUtilsTest {
@@ -249,6 +255,84 @@ public class FileUtilsTest {
         assertArrayEquals(expected, actual);
     }
 
+    //TODO(ravenwood) Remove the _$noRavenwood suffix and add @RavenwoodIgnore instead
+    @Test
+    public void testCopy_SocketToFile_FileToSocket$noRavenwood() throws Exception {
+        for (int size : DATA_SIZES ) {
+            final File src = new File(mTarget, "src");
+            final File dest = new File(mTarget, "dest");
+            byte[] expected = new byte[size];
+            byte[] actual = new byte[size];
+            new Random().nextBytes(expected);
+
+            // write test data in to src file
+            writeFile(src, expected);
+
+            // start server, get data from client and save to dest file (socket --> file)
+            FileDescriptor srvSocketFd = Os.socket(AF_INET, SOCK_STREAM, 0);
+            Os.bind(srvSocketFd, new InetSocketAddress("localhost", 0));
+            Os.listen(srvSocketFd, 5);
+            InetSocketAddress localSocketAddress = (InetSocketAddress) Os.getsockname(srvSocketFd);
+
+            final Thread srv = new Thread(new Runnable() {
+                public void run() {
+                    try {
+                        InetSocketAddress peerAddress = new InetSocketAddress();
+                        FileDescriptor srvConnFd = Os.accept(srvSocketFd, peerAddress);
+
+                        // read file size
+                        byte[] rcvFileSizeByteArray = new byte[8];
+                        Os.read(srvConnFd, rcvFileSizeByteArray, 0, rcvFileSizeByteArray.length);
+                        long rcvFileSize = 0;
+                        for (int i = 0; i < 8; i++) {
+                            rcvFileSize <<= 8;
+                            rcvFileSize |= (rcvFileSizeByteArray[i] & 0xFF);
+                        }
+
+                        FileOutputStream fileOutputStream = new FileOutputStream(dest);
+                        // copy data from socket to file
+                        FileUtils.copy(srvConnFd, fileOutputStream.getFD(), rcvFileSize, null, null, null);
+
+                        fileOutputStream.close();
+                        Os.close(srvConnFd);
+                        Os.close(srvSocketFd);
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+            });
+
+            srv.start();
+
+
+            // start client, get data from dest file and send to server (file --> socket)
+            FileDescriptor clientFd = Os.socket(AF_INET, SOCK_STREAM, 0);
+            Os.connect(clientFd, localSocketAddress.getAddress(), localSocketAddress.getPort());
+
+            FileInputStream fileInputStream = new FileInputStream(src);
+            long sndFileSize = src.length();
+            // send the file size to server
+            byte[] sndFileSizeByteArray = new byte[8];
+            for (int i = 7; i >= 0; i--) {
+                sndFileSizeByteArray[i] = (byte)(sndFileSize & 0xFF);
+                sndFileSize >>= 8;
+            }
+            Os.write(clientFd, sndFileSizeByteArray, 0, sndFileSizeByteArray.length);
+
+            // copy data from file to socket
+            FileUtils.copy(fileInputStream.getFD(), clientFd, src.length(), null, null, null);
+
+            fileInputStream.close();
+            Os.close(clientFd);
+
+            srv.join();
+
+            // read test data from dest file
+            actual = readFile(dest);
+            assertArrayEquals(expected, actual);
+        }
+    }
+
     @Test
     public void testIsFilenameSafe() throws Exception {
         assertTrue(FileUtils.isFilenameSafe(new File("foobar")));