Add safeReadAll() and return the result wrapped in a ReadResult object

Author: riclage

filesystem/src/main/java/com/nytimes/android/external/fs3/FSAllReader.java

@@ -3,14 +3,15 @@
 import com.nytimes.android.external.fs3.filesystem.FileSystem;
 import com.nytimes.android.external.store3.base.DiskAllRead;
 
+import com.nytimes.android.external.store3.base.ReadResult;
+import com.nytimes.android.external.store3.base.ReadResultFactory;
 import java.io.FileNotFoundException;
 
 import javax.annotation.Nonnull;
 
 import io.reactivex.Observable;
 import io.reactivex.exceptions.Exceptions;
 import okio.BufferedSource;
-import okio.Okio;
 
 /**
  * FSReader is used when persisting from file system
@@ -24,6 +25,25 @@ public FSAllReader(FileSystem fileSystem) {
         this.fileSystem = fileSystem;
     }
 
+    @Nonnull
+    @Override
+    public Observable<ReadResult<BufferedSource>> safeReadAll(@Nonnull final String path) {
+        return Observable.defer(() -> {
+            Observable<ReadResult<BufferedSource>> bufferedSourceObservable = null;
+            try {
+                bufferedSourceObservable = Observable
+                    .fromIterable(fileSystem.list(path))
+                    .flatMap(s ->
+                        Observable.defer(() -> Observable.just(fileSystem.read(s)))
+                            .map(ReadResultFactory::createSuccessResult)
+                            .onErrorReturn(ReadResultFactory::createFailureResult));
+            } catch (FileNotFoundException e) {
+                throw Exceptions.propagate(e);
+            }
+            return bufferedSourceObservable;
+        });
+    }
+
     @Nonnull
     @Override
     public Observable<BufferedSource> readAll(@Nonnull final String path) throws FileNotFoundException {
@@ -32,10 +52,13 @@ public Observable<BufferedSource> readAll(@Nonnull final String path) throws Fil
             try {
                 bufferedSourceObservable = Observable
                         .fromIterable(fileSystem.list(path))
-                        .flatMap(s ->
-                            Observable.defer(() -> Observable.just(fileSystem.read(s)))
-                                .onErrorReturn(throwable -> Okio.buffer(
-                                    ReadResultBufferedSourceFactory.createFailureResult(throwable))));
+                        .map(s -> {
+                            try {
+                                return fileSystem.read(s);
+                            } catch (FileNotFoundException e) {
+                                throw Exceptions.propagate(e);
+                            }
+                        });
             } catch (FileNotFoundException e) {
                 throw Exceptions.propagate(e);
             }

filesystem/src/main/java/com/nytimes/android/external/fs3/ReadResultBufferedSource.java

@@ -3,6 +3,7 @@
 
 import com.nytimes.android.external.fs3.filesystem.FileSystem;
 import com.nytimes.android.external.store3.base.AllPersister;
+import com.nytimes.android.external.store3.base.ReadResult;
 import com.nytimes.android.external.store3.base.impl.BarCode;
 
 import java.io.FileNotFoundException;
@@ -35,6 +36,12 @@ public SourceAllPersister(FileSystem fileSystem) {
         sourceFileWriter = new FSWriter<>(fileSystem,  new BarCodeReadAllPathResolver());
     }
 
+    @Nonnull
+    @Override
+    public Observable<ReadResult<BufferedSource>> safeReadAll(@Nonnull String path) {
+        return sourceFileAllReader.safeReadAll(path);
+    }
+
     @Nonnull
     @Override
     public Observable<BufferedSource> readAll(@Nonnull final String path) throws FileNotFoundException {

filesystem/src/main/java/com/nytimes/android/external/fs3/ReadResultBufferedSourceFactory.java

@@ -5,6 +5,7 @@
 import com.nytimes.android.external.fs3.filesystem.FileSystem;
 import com.nytimes.android.external.fs3.filesystem.FileSystemFactory;
 
+import com.nytimes.android.external.store3.base.ReadResult;
 import org.junit.Test;
 
 import java.io.ByteArrayInputStream;
@@ -47,6 +48,26 @@ public void readAll() throws IOException {
     }
 
     @Test
+    public void safeReadAllWithCrash() throws IOException {
+        File tempDir = createTempDir();
+        FileSystem fileSystem = new CrashOnReadFileSystem(tempDir);
+
+        //write different data to File System for each barcode
+        fileSystem.write(FOLDER + "/key.txt", source(CHALLAH));
+        fileSystem.write(FOLDER + "/key_crash.txt", source(CHALLAH));
+        fileSystem.write(FOLDER + "/" + INNER_FOLDER + "/key2.txt", source(CHALLAH_CHALLAH));
+        FSAllReader reader = new FSAllReader(fileSystem);
+        //read back all values for the FOLDER
+        Observable<ReadResult<BufferedSource>> observable = reader.safeReadAll(FOLDER);
+        observable.test()
+            .assertValueAt(0, bufferedSourceReadResult ->
+                bufferedSourceReadResult.getResult().readUtf8().equals(CHALLAH))
+            .assertValueAt(1, bufferedSourceReadResult -> !bufferedSourceReadResult.isSuccess())
+            .assertValueAt(2, bufferedSourceReadResult ->
+                bufferedSourceReadResult.getResult().readUtf8().equals(CHALLAH_CHALLAH));
+    }
+
+    @Test(expected = RuntimeException.class)
     public void readAllWithCrash() throws IOException {
         File tempDir = createTempDir();
         FileSystem fileSystem = new CrashOnReadFileSystem(tempDir);