Added ability for the transcoder to determine if a video file is open in another program to avoid trying to transcode/remove a partially written file; reworked the main transcode loop to handle one file at a time instead of archiving everything, then transcoding, then cleanup

src/main/java/tech/bitgoblin/io/IOUtils.java

@@ -1,6 +1,8 @@
 package tech.bitgoblin.io;
 
-import java.io.File;
+import tech.bitgoblin.Logger;
+
+import java.io.*;
 
 public class IOUtils {
 
@@ -24,4 +26,23 @@ public class IOUtils {
     return path;
   }
 
+  // checks to see if a file is currently locked/being written to.
+  public static boolean isFileLocked(File file) throws IOException {
+    String[] cmd = {"lsof", file.toString()};
+    Process process = Runtime.getRuntime().exec(cmd);
+    BufferedReader reader = new BufferedReader(new InputStreamReader(
+        process.getInputStream()));
+
+    boolean isOpen = false; // we'll change this if lsof returns that the file is open
+
+    String s;
+    while ((s = reader.readLine()) != null) {
+      if (s.endsWith(file.toString())) {
+        isOpen = true;
+      }
+    }
+
+    return isOpen;
+  }
+
 }

src/main/java/tech/bitgoblin/transcoder/Repository.java

@@ -40,25 +40,21 @@ public class Repository {
   }
 
   // archives files in the ingest directory
-  public void archiveIngest(File[] sourceFiles) {
-    for (File f : sourceFiles) {
-      Path filePath = Path.of(f.toString());
-      String filename = filePath.getFileName().toString();
-      String archivePath = Paths.get(this.archivePath, filename).toString();
+  public void archiveFile(File sourceFile) {
+    Path filePath = Path.of(sourceFile.toString());
+    String filename = filePath.getFileName().toString();
+    String archivePath = Paths.get(this.archivePath, filename).toString();
 
-      try {
-        Files.copy(filePath, Paths.get(archivePath), StandardCopyOption.COPY_ATTRIBUTES, StandardCopyOption.REPLACE_EXISTING);
-      } catch (IOException e) {
-        throw new RuntimeException(e);
-      }
+    try {
+      Files.copy(filePath, Paths.get(archivePath), StandardCopyOption.COPY_ATTRIBUTES, StandardCopyOption.REPLACE_EXISTING);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
     }
   }
 
   // clean up the ingest directory once we're done
-  public void cleanupIngest(File[] sourceFiles) {
-    for (File f : sourceFiles) {
-      f.delete();
-    }
+  public void cleanupFile(File sourceFile) {
+    sourceFile.delete();
   }
 
   // returns the repository's path

src/main/java/tech/bitgoblin/transcoder/RunTranscoderTask.java

@@ -1,5 +1,6 @@
 package tech.bitgoblin.transcoder;
 
+import java.io.IOException;
 import java.util.TimerTask;
 
 public class RunTranscoderTask extends TimerTask {
@@ -13,7 +14,11 @@ public class RunTranscoderTask extends TimerTask {
   @Override
   public void run() {
     // archive the files
-    transcoder.run();
+    try {
+      transcoder.run();
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
   }
 
 }

src/main/java/tech/bitgoblin/transcoder/Transcoder.java

@@ -31,54 +31,29 @@ public class Transcoder {
   }
 
   // create a periodic timer task and start it
-  public void run() {
+  public void run() throws IOException {
     // pull list of files to transcode
     File[] sourceFiles = this.repo.searchIngest();
 
-    // archive files
-    this.repo.archiveIngest(sourceFiles);
-    // transcode files
-    this.transcode(sourceFiles);
-    // cleanup old files
-    this.repo.cleanupIngest(sourceFiles);
-  }
-
-  // transcode files in the working directory
-  public void transcode(File[] sourceFiles) {
-    // check if the ingest directory is empty
+    // check if we have anything to process
     if (sourceFiles.length == 0) {
-      Logger.logger.info("There is nothing to transcode in ingest.");
-      return;
+      Logger.logger.info("There is nothing in ingest, skipping transcode run.");
     }
 
-    // transcode
-    Logger.logger.info("Transcoding video files ingest...");
-    for (File f : sourceFiles) {
-      String filePath = f.toString().substring(0, f.toString().lastIndexOf("."));
-      String filename = Paths.get(filePath).getFileName().toString();
-      String outputPath = Paths.get(this.repo.getOutputPath(), String.format("%s.mov", filename)).toString();
-
-      String cmd = String.format("%s -i %s -y -f %s -c:v %s -vf %s -profile:v %s -c:a %s %s",
-        this.ffmpeg_path, // FFMPEG binary path
-        f.toString(), // input file
-        this.config.getString("transcoder.video_format"), // video container format
-        this.config.getString("transcoder.video_codec"), // video codec
-        this.config.getString("transcoder.video_parameters"), // video format
-        this.config.getString("transcoder.video_profile"), // video profile
-        this.config.getString("transcoder.audio_codec"), // audio codec
-        outputPath // output file path
-      );
-
-      ProcessBuilder pb = new ProcessBuilder(cmd.split("\\s+"));
-      pb.inheritIO(); // use the java processes' input and output streams
-      try {
-        Process process = pb.start();
-        int ret = process.waitFor();
-        Logger.logger.info("Program exited with code: %d", ret);
-        Logger.logger.info("");
-      } catch (IOException | InterruptedException e) {
-        throw new RuntimeException(e);
+    // loop through each file
+    for (File sf : sourceFiles) {
+      // check if the file is open before attempting to transcode it
+      if (IOUtils.isFileLocked(sf)) {
+        Logger.logger.info(String.format("Skipping %s because it is open in another program.", sf.toString()));
+        continue;
       }
+
+      // archive files
+      this.repo.archiveFile(sf);
+      // transcode files
+      this.transcodeFile(sf);
+      // cleanup old files
+      this.repo.cleanupFile(sf);
     }
 
     // end output
@@ -86,4 +61,33 @@ public class Transcoder {
     Logger.logger.info("");
   }
 
+  // transcode files in the working directory
+  public void transcodeFile(File sourceFile) throws IOException {
+    String filePath = sourceFile.toString().substring(0, sourceFile.toString().lastIndexOf("."));
+    String filename = Paths.get(filePath).getFileName().toString();
+    String outputPath = Paths.get(this.repo.getOutputPath(), String.format("%s.mov", filename)).toString();
+
+    String cmd = String.format("%s -i %s -y -f %s -c:v %s -vf %s -profile:v %s -c:a %s %s",
+      this.ffmpeg_path, // FFMPEG binary path
+      sourceFile.toString(), // input file
+      this.config.getString("transcoder.video_format"), // video container format
+      this.config.getString("transcoder.video_codec"), // video codec
+      this.config.getString("transcoder.video_parameters"), // video format
+      this.config.getString("transcoder.video_profile"), // video profile
+      this.config.getString("transcoder.audio_codec"), // audio codec
+      outputPath // output file path
+    );
+
+    ProcessBuilder pb = new ProcessBuilder(cmd.split("\\s+"));
+    pb.inheritIO(); // use the java processes' input and output streams
+    try {
+      Process process = pb.start();
+      int ret = process.waitFor();
+      Logger.logger.info(String.format("Program exited with code: %d", ret));
+      Logger.logger.info("");
+    } catch (IOException | InterruptedException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
 }

src/test/java/tech/bitgoblin/io/IOUtilsTest.java

@@ -1,15 +1,21 @@
 package tech.bitgoblin.io;
 
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
 
 public class IOUtilsTest {
 
   private static String testDir = "test-temp";
+  private static String testFile = "test.txt";
 
   @Test
   public void shouldCreateDirectory() {
@@ -28,9 +34,30 @@ public class IOUtilsTest {
     IOUtils.resolveTilda("~test");
   }
 
+  @Test
+  public void fileShouldBeLocked() throws IOException {
+    RandomAccessFile raf = new RandomAccessFile(testFile, "rw");
+    assertTrue(IOUtils.isFileLocked(new File(testFile)));
+  }
+
+  @Test
+  public void fileShouldNotBeLocked() throws IOException {
+    RandomAccessFile raf = new RandomAccessFile("test.txt", "rw");
+    raf.close();
+    assertFalse(IOUtils.isFileLocked(new File(testFile)));
+  }
+
+  @BeforeClass
+  // ensure that test files are created before running tests
+  public static void setup() throws IOException {
+    new File(testFile).createNewFile();
+  }
+
   @AfterClass
+  // ensure test files are cleaned up from the environment
   public static void cleanup() {
     new File(testDir).delete();
+    new File(testFile).delete();
   }
 
 }