feat: update cloudstorageconfiguration to improve cross-bucket perfor…

…mance

google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystem.java

@@ -61,10 +61,10 @@ public final class CloudStorageFileSystem extends FileSystem {
   public static final int BLOCK_SIZE_DEFAULT = 2 * 1024 * 1024;
   public static final FileTime FILE_TIME_UNKNOWN = FileTime.fromMillis(0);
   public static final Set<String> SUPPORTED_VIEWS = ImmutableSet.of(BASIC_VIEW, GCS_VIEW);
-
   private final CloudStorageFileSystemProvider provider;
   private final String bucket;
   private final CloudStorageConfiguration config;
+  private static CloudStorageFileSystem cloudStorageFileSystem;
 
   // Users can change this: then this affects every filesystem object created
   // later, including via SPI. This is meant to be done only once, at the beginning
@@ -134,6 +134,18 @@ public static CloudStorageFileSystem forBucket(String bucket) {
     return forBucket(bucket, userSpecifiedDefault);
   }
 
+  /**
+   * Creates new file system instance for {@code bucket}, with existing provider and configuration.
+   *
+   * @param bucketName the name of the bucket to initialize CloudStorageFileSystem Object.
+   * @return CloudStorageFileSystem Object with existing provider and config.
+   * @see #forBucket(String)
+   */
+  private static CloudStorageFileSystem getExistingCloudStorageConfiguration(String bucketName) {
+    return new CloudStorageFileSystem(
+        cloudStorageFileSystem.provider(), bucketName, cloudStorageFileSystem.config());
+  }
+
   /**
    * Creates new file system instance for {@code bucket}, with customizable settings.
    *
@@ -144,8 +156,10 @@ public static CloudStorageFileSystem forBucket(String bucket, CloudStorageConfig
     checkArgument(
         !bucket.startsWith(URI_SCHEME + ":"), "Bucket name must not have schema: %s", bucket);
     checkNotNull(config);
-    return new CloudStorageFileSystem(
-        new CloudStorageFileSystemProvider(config.userProject()), bucket, config);
+    return (cloudStorageFileSystem != null && cloudStorageFileSystem.config().equals(config))
+        ? getExistingCloudStorageConfiguration(bucket)
+        : new CloudStorageFileSystem(
+            new CloudStorageFileSystemProvider(config.userProject()), bucket, config);
   }
 
   /**
@@ -168,10 +182,12 @@ public static CloudStorageFileSystem forBucket(
       String bucket, CloudStorageConfiguration config, @Nullable StorageOptions storageOptions) {
     checkArgument(
         !bucket.startsWith(URI_SCHEME + ":"), "Bucket name must not have schema: %s", bucket);
-    return new CloudStorageFileSystem(
-        new CloudStorageFileSystemProvider(config.userProject(), storageOptions),
-        bucket,
-        checkNotNull(config));
+    return (cloudStorageFileSystem != null && cloudStorageFileSystem.config().equals(config))
+        ? getExistingCloudStorageConfiguration(bucket)
+        : new CloudStorageFileSystem(
+            new CloudStorageFileSystemProvider(config.userProject(), storageOptions),
+            bucket,
+            checkNotNull(config));
   }
 
   CloudStorageFileSystem(
@@ -195,6 +211,7 @@ public static CloudStorageFileSystem forBucket(
     }
     this.provider = provider;
     this.config = config;
+    this.cloudStorageFileSystem = this;
   }
 
   @Override

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemTest.java

@@ -18,6 +18,9 @@
 
 import static com.google.common.truth.Truth.assertThat;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 
 import com.google.cloud.storage.StorageOptions;
 import com.google.cloud.storage.contrib.nio.testing.LocalStorageHelper;
@@ -334,6 +337,43 @@ public void testDeleteRecursive() throws IOException {
     }
   }
 
+  @Test
+  public void testSameProvider() {
+    try (CloudStorageFileSystem sourceFileSystem =
+        CloudStorageFileSystem.forBucket(
+            "bucket",
+            CloudStorageConfiguration.builder().permitEmptyPathComponents(true).build())) {
+      CloudStorageFileSystem destFileSystem =
+          CloudStorageFileSystem.forBucket(
+              "new-bucket",
+              CloudStorageConfiguration.builder().permitEmptyPathComponents(true).build());
+      assertEquals(sourceFileSystem.provider(), destFileSystem.provider());
+      assertEquals(sourceFileSystem.config(), destFileSystem.config());
+      assertEquals("bucket", sourceFileSystem.bucket());
+      assertEquals("new-bucket", destFileSystem.bucket());
+    } catch (IOException e) {
+
+    }
+  }
+
+  @Test
+  public void testDifferentProvider() {
+    try (CloudStorageFileSystem sourceFileSystem =
+        CloudStorageFileSystem.forBucket(
+            "bucket",
+            CloudStorageConfiguration.builder().permitEmptyPathComponents(true).build())) {
+      CloudStorageFileSystem destFileSystem =
+          CloudStorageFileSystem.forBucket(
+              "new-bucket",
+              CloudStorageConfiguration.builder().permitEmptyPathComponents(false).build());
+      assertFalse(sourceFileSystem.provider() == destFileSystem.provider());
+      assertNotEquals(sourceFileSystem.config(), destFileSystem.config());
+      assertEquals("bucket", sourceFileSystem.bucket());
+      assertEquals("new-bucket", destFileSystem.bucket());
+    } catch (IOException e) {
+      // fail
+    }
+  }
   /**
    * Delete the given directory and all of its contents if non-empty.
    *

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/it/ITGcsNio.java

@@ -20,6 +20,8 @@
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 
 import com.google.api.client.http.HttpResponseException;
 import com.google.cloud.storage.BlobInfo;
@@ -96,6 +98,7 @@ public class ITGcsNio {
 
   private static final Logger log = Logger.getLogger(ITGcsNio.class.getName());
   private static final String BUCKET = RemoteStorageHelper.generateBucketName();
+  private static final String TARGET_BUCKET = RemoteStorageHelper.generateBucketName();
   private static final String REQUESTER_PAYS_BUCKET =
       RemoteStorageHelper.generateBucketName() + "_rp";
   private static final String SML_FILE = "tmp-test-small-file.txt";
@@ -119,6 +122,7 @@ public static void beforeClass() throws IOException {
     storage = storageOptions.getService();
     // create and populate test bucket
     storage.create(BucketInfo.of(BUCKET));
+    storage.create(BucketInfo.of(TARGET_BUCKET));
     fillFile(storage, BUCKET, SML_FILE, SML_SIZE);
     fillFile(storage, BUCKET, BIG_FILE, BIG_SIZE);
     BucketInfo requesterPaysBucket =
@@ -1040,6 +1044,34 @@ public ImmutableList<Path> getPaths() {
     }
   }
 
+  @Test
+  public void testCopyWithSameProvider() throws IOException {
+    CloudStorageFileSystem sourceFileSystem = getTestBucket();
+    CloudStorageFileSystem targetFileSystem =
+        CloudStorageFileSystem.forBucket(
+            TARGET_BUCKET, CloudStorageConfiguration.DEFAULT, storageOptions);
+    Path sourceFileSystemPath = sourceFileSystem.getPath(SML_FILE);
+    Path targetFileSystemPath = targetFileSystem.getPath(PREFIX + randomSuffix());
+    Files.copy(sourceFileSystemPath, targetFileSystemPath);
+    assertEquals(sourceFileSystem.provider(), targetFileSystem.provider());
+    assertEquals(sourceFileSystem.config(), targetFileSystem.config());
+  }
+
+  @Test
+  public void testCopyWithDifferentProvider() throws IOException {
+    CloudStorageFileSystem sourceFileSystem = getTestBucket();
+    CloudStorageFileSystem targetFileSystem =
+        CloudStorageFileSystem.forBucket(
+            TARGET_BUCKET,
+            CloudStorageConfiguration.builder().permitEmptyPathComponents(true).build(),
+            storageOptions);
+    Path sourceFileSystemPath = sourceFileSystem.getPath(SML_FILE);
+    Path targetFileSystemPath = targetFileSystem.getPath(PREFIX + randomSuffix());
+    Files.copy(sourceFileSystemPath, targetFileSystemPath);
+    assertThat(sourceFileSystem.provider() == targetFileSystem.provider()).isFalse();
+    assertNotEquals(sourceFileSystem.config(), targetFileSystem.config());
+  }
+
   private CloudStorageFileSystem getTestBucket() throws IOException {
     // in typical usage we use the single-argument version of forBucket
     // and rely on the user being logged into their project with the