Feature/filepersister (#115)

* generic file persister with path resolver

filesystem/src/main/java/com/nytimes/android/external/fs/BarCodePathResolver.java

@@ -0,0 +1,10 @@
+package com.nytimes.android.external.fs;
+
+import com.nytimes.android.external.store.base.impl.BarCode;
+
+class BarCodePathResolver implements PathResolver<BarCode> {
+    @Override
+    public String resolve(BarCode key) {
+        return key.toString();
+    }
+}

filesystem/src/main/java/com/nytimes/android/external/fs/FSReader.java

@@ -0,0 +1,41 @@
+package com.nytimes.android.external.fs;
+
+import com.nytimes.android.external.fs.filesystem.FileSystem;
+import com.nytimes.android.external.store.base.DiskRead;
+
+import java.io.FileNotFoundException;
+import java.util.concurrent.Callable;
+
+import javax.annotation.Nonnull;
+
+import okio.BufferedSource;
+import rx.Observable;
+
+/**
+ * FSReader is used when persisting from file system
+ * PathResolver will be used in creating file system paths based on cache keys.
+ * Make sure to have keys containing same data resolve to same "path"
+ * @param <T> key type
+ */
+public class FSReader<T> implements DiskRead<BufferedSource, T> {
+    final FileSystem fileSystem;
+    final PathResolver<T> pathResolver;
+
+    public FSReader(FileSystem fileSystem, PathResolver<T> pathResolver) {
+        this.fileSystem = fileSystem;
+        this.pathResolver = pathResolver;
+    }
+
+    @Nonnull
+    @Override
+    public Observable<BufferedSource> read(final T id) {
+        return fileSystem.exists(pathResolver.resolve(id)) ?
+                Observable.fromCallable(new Callable<BufferedSource>() {
+                    @Override
+                    public BufferedSource call() throws FileNotFoundException {
+                        return fileSystem.read(pathResolver.resolve(id));
+                    }
+                }) :
+                Observable.<BufferedSource>empty();
+    }
+}

filesystem/src/main/java/com/nytimes/android/external/fs/FSWriter.java

@@ -0,0 +1,40 @@
+package com.nytimes.android.external.fs;
+
+import com.nytimes.android.external.fs.filesystem.FileSystem;
+import com.nytimes.android.external.store.base.DiskWrite;
+
+import java.util.concurrent.Callable;
+
+import javax.annotation.Nonnull;
+
+import okio.BufferedSource;
+import rx.Observable;
+/**
+ * FSReader is used when persisting to file system
+ * PathResolver will be used in creating file system paths based on cache keys.
+ * Make sure to have keys containing same data resolve to same "path"
+ * @param <T> key type
+ */
+public class FSWriter<T> implements DiskWrite<BufferedSource, T> {
+    final FileSystem fileSystem;
+    final PathResolver<T> pathResolver;
+
+    public FSWriter(FileSystem fileSystem, PathResolver<T> pathResolver) {
+        this.fileSystem = fileSystem;
+        this.pathResolver = pathResolver;
+    }
+
+    @Nonnull
+    @Override
+    public Observable<Boolean> write(final T barCode, final BufferedSource data) {
+        return Observable.fromCallable(new Callable<Boolean>() {
+            @Nonnull
+            @Override
+            @SuppressWarnings("PMD.SignatureDeclareThrowsException")
+            public Boolean call() throws Exception {
+                fileSystem.write(pathResolver.resolve(barCode), data);
+                return true;
+            }
+        });
+    }
+}

filesystem/src/main/java/com/nytimes/android/external/fs/FileSystemPersister.java

@@ -0,0 +1,48 @@
+package com.nytimes.android.external.fs;
+
+import com.nytimes.android.external.fs.filesystem.FileSystem;
+import com.nytimes.android.external.store.base.Persister;
+
+import javax.annotation.Nonnull;
+
+import okio.BufferedSource;
+import rx.Observable;
+/**
+ * FileSystemPersister is used when persisting to/from file system
+ * PathResolver will be used in creating file system paths based on cache keys.
+ * Make sure to have keys containing same data resolve to same "path"
+ * @param <T> key type
+ */
+public final class FileSystemPersister<T> implements Persister<BufferedSource, T> {
+    final FileSystem fileSystem;
+    private final FSReader<T> fileReader;
+    private final FSWriter<T> fileWriter;
+
+    private FileSystemPersister(FileSystem fileSystem, PathResolver<T> pathResolver) {
+
+        fileReader = new FSReader<>(fileSystem, pathResolver);
+        fileWriter = new FSWriter<>(fileSystem, pathResolver);
+        this.fileSystem = fileSystem;
+    }
+
+    @Nonnull
+    public static <T> Persister<BufferedSource, T> create(FileSystem fileSystem,
+                                                          PathResolver<T> pathResolver) {
+        if (fileSystem == null) {
+            throw new IllegalArgumentException("root file cannot be null.");
+        }
+        return new FileSystemPersister<>(fileSystem, pathResolver);
+    }
+
+    @Nonnull
+    @Override
+    public Observable<BufferedSource> read(final T id) {
+        return fileReader.read(id);
+    }
+
+    @Nonnull
+    @Override
+    public Observable<Boolean> write(final T barCode, final BufferedSource data) {
+        return fileWriter.write(barCode, data);
+    }
+}

filesystem/src/main/java/com/nytimes/android/external/fs/PathResolver.java

@@ -0,0 +1,15 @@
+package com.nytimes.android.external.fs;
+
+/**
+ * Created by 206847 on 2/8/17.
+ */
+
+/**
+ * PathResolver will be used in creating file system paths based on cache keys.
+ * Make sure to have keys containing same data resolve to same "path"
+ * @param <T> Store key/request param type
+ */
+public interface PathResolver<T> {
+
+    String resolve(T key);
+}

filesystem/src/main/java/com/nytimes/android/external/fs/SourceFileReader.java

@@ -5,42 +5,20 @@ import com.nytimes.android.external.store.base.DiskRead;
 import com.nytimes.android.external.store.base.RecordState;
 import com.nytimes.android.external.store.base.impl.BarCode;
 
-import java.io.FileNotFoundException;
-import java.util.concurrent.Callable;
 import java.util.concurrent.TimeUnit;
 
 import javax.annotation.Nonnull;
-import javax.inject.Inject;
 
 import okio.BufferedSource;
-import rx.Observable;
 
 import static com.nytimes.android.external.fs.SourcePersister.pathForBarcode;
 
-public class SourceFileReader implements DiskRead<BufferedSource, BarCode> {
+public class SourceFileReader extends FSReader<BarCode> implements DiskRead<BufferedSource, BarCode> {
 
-    final FileSystem fileSystem;
-
-    @Inject
     public SourceFileReader(FileSystem fileSystem) {
-        this.fileSystem = fileSystem;
+        super(fileSystem, new BarCodePathResolver());
     }
 
-    @Nonnull
-    @Override
-    public Observable<BufferedSource> read(@Nonnull final BarCode barCode) {
-        return Observable.fromCallable(new Callable<BufferedSource>() {
-            @Nonnull
-            @Override
-            public BufferedSource call() throws FileNotFoundException {
-                return fileSystem.read(pathForBarcode(barCode));
-            }
-        });
-    }
-
-    public boolean exists(@Nonnull BarCode barCode) {
-        return fileSystem.exists(pathForBarcode(barCode));
-    }
 
     @Nonnull
     public RecordState getRecordState(@Nonnull BarCode barCode,

filesystem/src/main/java/com/nytimes/android/external/fs/SourceFileWriter.java

@@ -4,38 +4,12 @@ import com.nytimes.android.external.fs.filesystem.FileSystem;
 import com.nytimes.android.external.store.base.DiskWrite;
 import com.nytimes.android.external.store.base.impl.BarCode;
 
-import java.util.concurrent.Callable;
-
-import javax.annotation.Nonnull;
-import javax.inject.Inject;
-
 import okio.BufferedSource;
-import rx.Observable;
 
-import static com.nytimes.android.external.fs.SourcePersister.pathForBarcode;
-import static okio.Okio.buffer;
+public class SourceFileWriter extends FSWriter<BarCode> implements DiskWrite<BufferedSource, BarCode> {
 
-public class SourceFileWriter implements DiskWrite<BufferedSource, BarCode> {
-
-    final FileSystem fileSystem;
-
-    @Inject
     public SourceFileWriter(FileSystem fileSystem) {
-        this.fileSystem = fileSystem;
+        super(fileSystem, new BarCodePathResolver());
     }
 
-
-    @Nonnull
-    @Override
-    public Observable<Boolean> write(@Nonnull final BarCode barCode, @Nonnull final BufferedSource data) {
-        return Observable.fromCallable(new Callable<Boolean>() {
-            @Nonnull
-            @Override
-            @SuppressWarnings("PMD.SignatureDeclareThrowsException")
-            public Boolean call() throws Exception {
-                fileSystem.write(pathForBarcode(barCode), buffer(data));
-                return true;
-            }
-        });
-    }
 }

filesystem/src/main/java/com/nytimes/android/external/fs/SourcePersister.java

@@ -41,7 +41,7 @@ public class SourcePersister implements Persister<BufferedSource, BarCode>{
     @Nonnull
     @Override
     public Observable<BufferedSource> read(@Nonnull final BarCode barCode) {
-        return sourceFileReader.exists(barCode) ? sourceFileReader.read(barCode) : Observable.<BufferedSource>empty();
+        return sourceFileReader.read(barCode);
     }
 
     @Nonnull

filesystem/src/main/java/com/nytimes/android/external/fs/SourcePersisterFactory.java

@@ -39,10 +39,11 @@ public final class SourcePersisterFactory {
      * persistence {@link com.nytimes.android.external.fs.filesystem.FileSystem}.
      **/
     @Nonnull
-    public static Persister<BufferedSource, BarCode> create(@Nonnull FileSystem fileSystem)  {
+    public static Persister<BufferedSource, BarCode> create(@Nonnull FileSystem fileSystem) {
         if (fileSystem == null) {
             throw new IllegalArgumentException("fileSystem cannot be null.");
         }
         return new SourcePersister(fileSystem);
     }
+
 }

filesystem/src/test/java/com/nytimes/android/external/fs/FilePersisterTest.java

@@ -0,0 +1,79 @@
+package com.nytimes.android.external.fs;
+
+import com.nytimes.android.external.fs.filesystem.FileSystem;
+import com.nytimes.android.external.store.base.Persister;
+import com.nytimes.android.external.store.base.impl.BarCode;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.NoSuchElementException;
+
+import okio.BufferedSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.when;
+
+public class FilePersisterTest {
+    @Rule
+    public ExpectedException expectedException = ExpectedException.none();
+
+    @Mock
+    FileSystem fileSystem;
+    @Mock
+    BufferedSource bufferedSource;
+
+    private final BarCode simple = new BarCode("type", "key");
+    private final String resolvedPath = new BarCodePathResolver().resolve(simple);
+    private Persister<BufferedSource, BarCode> fileSystemPersister;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        fileSystemPersister = FileSystemPersister.create(fileSystem, new BarCodePathResolver());
+    }
+
+    @Test
+    public void readExists() throws FileNotFoundException {
+        when(fileSystem.exists(resolvedPath))
+                .thenReturn(true);
+        when(fileSystem.read(resolvedPath)).thenReturn(bufferedSource);
+
+        BufferedSource returnedValue = fileSystemPersister.read(simple).toBlocking().single();
+        assertThat(returnedValue).isEqualTo(bufferedSource);
+    }
+
+    @Test
+    public void readDoesNotExist() throws FileNotFoundException {
+        expectedException.expect(NoSuchElementException.class);
+        when(fileSystem.exists(resolvedPath))
+                .thenReturn(false);
+
+        fileSystemPersister.read(simple).toBlocking().single();
+    }
+
+    @Test
+    public void writeThenRead() throws IOException {
+        when(fileSystem.read(resolvedPath)).thenReturn(bufferedSource);
+        when(fileSystem.exists(resolvedPath)).thenReturn(true);
+        fileSystemPersister.write(simple, bufferedSource).toBlocking().single();
+        BufferedSource source = fileSystemPersister.read(simple).toBlocking().first();
+        InOrder inOrder = inOrder(fileSystem);
+        inOrder.verify(fileSystem).write(resolvedPath, bufferedSource);
+        inOrder.verify(fileSystem).exists(resolvedPath);
+        inOrder.verify(fileSystem).read(resolvedPath);
+
+        assertThat(source).isEqualTo(bufferedSource);
+
+
+    }
+
+}

filesystem/src/test/java/com/nytimes/android/external/fs/RecordPersisterTest.java

@@ -41,9 +41,9 @@ public class RecordPersisterTest {
 
     @Test
     public void readExists() throws FileNotFoundException {
-        when(fileSystem.exists(SourcePersister.pathForBarcode(simple)))
+        when(fileSystem.exists(simple.toString()))
                 .thenReturn(true);
-        when(fileSystem.read(SourcePersister.pathForBarcode(simple))).thenReturn(bufferedSource);
+        when(fileSystem.read(simple.toString())).thenReturn(bufferedSource);
 
         BufferedSource returnedValue = sourcePersister.read(simple).toBlocking().single();
         assertThat(returnedValue).isEqualTo(bufferedSource);

filesystem/src/test/java/com/nytimes/android/external/fs/SourcePersisterTest.java

@@ -40,9 +40,9 @@ public class SourcePersisterTest {
 
     @Test
     public void readExists() throws FileNotFoundException {
-        when(fileSystem.exists(SourcePersister.pathForBarcode(simple)))
+        when(fileSystem.exists(simple.toString()))
                 .thenReturn(true);
-        when(fileSystem.read(SourcePersister.pathForBarcode(simple))).thenReturn(bufferedSource);
+        when(fileSystem.read(simple.toString())).thenReturn(bufferedSource);
 
         BufferedSource returnedValue = sourcePersister.read(simple).toBlocking().single();
         assertThat(returnedValue).isEqualTo(bufferedSource);

store/src/main/java/com/nytimes/android/external/store/base/Persister.java

@@ -6,6 +6,7 @@ import rx.Observable;
 
 /**
  * Interface for fetching data from persister
+ * when implementing also think about implementing PathResolver to ease in creating primary keys
  *
  * @param <Raw> data type before parsing
  */