Delete outdated libs as part of unpack()

Summary: We might want different logic for different so sources.

Reviewed By: danjin250

Differential Revision: D49539327

fbshipit-source-id: fc868e95d0c0063efc1964f4c381c5483c3f9560

java/com/facebook/soloader/ExoSoSource.java

@@ -126,6 +126,7 @@ public Dso[] getDsos() throws IOException {
     @Override
     public void unpack(File soDirectory) throws IOException {
       byte[] ioBuffer = new byte[32 * 1024];
+      deleteUnmentionedFiles(mDsos);
       for (FileDso fileDso : mDsos) {
         FileInputStream is = new FileInputStream(fileDso.backingFile);
         try (InputDso inputDso = new InputDso(fileDso, is)) {

java/com/facebook/soloader/ExtractFromZipSoSource.java

@@ -136,6 +136,7 @@ public final Dso[] getDsos() throws IOException {
     public void unpack(File soDirectory) throws IOException {
       byte[] ioBuffer = new byte[32 * 1024];
       ZipDso[] dsos = getExtractableDsosFromZip();
+      deleteUnmentionedFiles(dsos);
       for (ZipDso zipDso : dsos) {
         InputStream is = mZipFile.getInputStream(zipDso.backingEntry);
         try (InputDso inputDso = new InputDso(zipDso, is)) {

java/com/facebook/soloader/UnpackingSoSource.java

@@ -136,7 +136,7 @@ private static void writeState(File stateFileName, byte state, boolean runFsync)
   }
 
   /** Delete files not mentioned in the given DSO list. */
-  private void deleteUnmentionedFiles(Dso[] dsos) throws IOException {
+  protected void deleteUnmentionedFiles(Dso[] dsos) throws IOException {
     String[] existingFiles = soDirectory.list();
     if (existingFiles == null) {
       throw new IOException("unable to list directory " + soDirectory);
@@ -169,6 +169,7 @@ private void deleteUnmentionedFiles(Dso[] dsos) throws IOException {
   protected abstract static class Unpacker implements Closeable {
     public abstract Dso[] getDsos() throws IOException;
 
+    /* Unpacks to soDirectory and removes existing outdated libs */
     public abstract void unpack(File soDirectory) throws IOException;
 
     @Override
@@ -358,17 +359,10 @@ private boolean refreshLocked(final FileLocker lock, final int flags) throws IOE
     final boolean runFsync = ((flags & PREPARE_FLAG_DISABLE_FS_SYNC_JOB) == 0);
     LogUtil.v(TAG, "so store dirty: regenerating");
     writeState(stateFileName, STATE_DIRTY, runFsync);
-    Dso[] desiredDsos = null;
     try (Unpacker u = makeUnpacker(forceUnpacking)) {
-      desiredDsos = u.getDsos();
-      deleteUnmentionedFiles(desiredDsos);
       u.unpack(soDirectory);
     }
 
-    if (desiredDsos == null) {
-      return false; // No sync needed
-    }
-
     // N.B. We can afford to write the deps file without fsyncs because we've marked the DSO
     // store STATE_DIRTY, which will cause us to ignore all intermediate state when regenerating it.
     // That is, it's okay for the depsFile blocks to hit the disk before the actual DSO data file