Merge remote-tracking branch 'origin/development' into dev/sharding-squash

Author: bogovicj

src/main/java/org/janelia/saalfeldlab/n5/CachedGsonKeyValueN5Writer.java

@@ -57,19 +57,11 @@ default void createGroup(final String path) throws N5Exception {
 		// avoid hitting the backend if this path is already a group according to the cache
 		// else if exists is true (then a dataset is present) so throw an exception to avoid
 		// overwriting / invalidating existing data
-		if (cacheMeta()) {
-			if (getCache().isGroup(normalPath, getAttributesKey()))
-				return;
-			else if (getCache().exists(normalPath, getAttributesKey())) {
-				throw new N5Exception("Can't make a group on existing path.");
-			}
-		}
+		if (groupExists(normalPath))
+			return;
+		else if (datasetExists(normalPath))
+			throw new N5Exception("Can't make a group on existing dataset.");
 
-		// N5Writer.super.createGroup(path);
-		/*
-		 * the lines below duplicate the single line above but would have to call
-		 * normalizeGroupPath again the below duplicates code, but avoids extra work
-		 */
 		getKeyValueAccess().createDirectories(absoluteGroupPath(normalPath));
 
 		if (cacheMeta()) {

src/main/java/org/janelia/saalfeldlab/n5/HttpKeyValueAccess.java

@@ -158,7 +158,7 @@ public boolean exists(final String normalPath) {
 	public boolean isDirectory(final String normalPath) {
 
 		try {
-			requireValidHttpResponse(getDirectoryPath(normalPath), HEAD, (code,  msg,http) -> {
+			requireValidHttpResponse(getDirectoryPath(normalPath), HEAD, false, (code,  msg,http) -> {
 				final N5Exception cause = validExistsResponse(code, "Error checking directory: " + normalPath, msg, true);
 				if (code >= 300 && code < 400) {
 					final String redirectLocation = http.getHeaderField("Location");
@@ -200,7 +200,7 @@ public boolean isFile(final String normalPath) {
 
 		/* Files must not end in `/` And Don't accept a redirect to a location ending in `/` */
 		try {
-			requireValidHttpResponse(getFilePath(normalPath), HEAD, (code, msg, http) -> {
+			requireValidHttpResponse(getFilePath(normalPath), HEAD, false, (code, msg, http) -> {
 				final N5Exception cause = validExistsResponse(code, "Error accessing file: " + normalPath, msg, true);
 				if (code >= 300 && code < 400) {
 					final String redirectLocation = http.getHeaderField("Location");
@@ -316,12 +316,17 @@ private HttpURLConnection requireValidHttpResponse(String uri, String method, St
 	}
 
 	private HttpURLConnection requireValidHttpResponse(String uri, String method, TriFunction<Integer, String, HttpURLConnection, N5Exception> filterCode) throws N5Exception {
+		return requireValidHttpResponse(uri, method, true, filterCode);
+	}
+
+	private HttpURLConnection requireValidHttpResponse(String uri, String method, boolean followRedirects, TriFunction<Integer, String, HttpURLConnection, N5Exception> filterCode) throws N5Exception {
 
 		final int code;
 		final HttpURLConnection http;
 		final String responseMsg;
 		try {
 			http = httpRequest(uri, method);
+			http.setInstanceFollowRedirects(followRedirects);
 			code = http.getResponseCode();
 			responseMsg = http.getResponseMessage();
 		} catch (IOException e) {

src/test/java/org/janelia/saalfeldlab/n5/http/HttpReaderFsWriter.java

@@ -39,8 +39,7 @@
 import org.janelia.saalfeldlab.n5.GsonKeyValueN5Writer;
 import org.janelia.saalfeldlab.n5.KeyValueAccess;
 import org.janelia.saalfeldlab.n5.N5Exception;
-import org.janelia.saalfeldlab.n5.codec.BlockCodecInfo;
-import org.janelia.saalfeldlab.n5.codec.DataCodecInfo;
+import org.janelia.saalfeldlab.n5.N5KeyValueReader;
 
 import java.io.Serializable;
 import java.lang.reflect.Field;
@@ -70,8 +69,13 @@ public <W extends GsonKeyValueN5Writer, R extends GsonKeyValueN5Reader> HttpRead
 			if (cachedReader.cacheMeta()) {
 				/* Hack necessary to test HTTP reader caching without creating the data entirely first */
 				try {
-					// Access the private 'cache' field in the reader
-					final Field cacheField = reader.getClass().getDeclaredField("cache");
+					// Access the private 'cache' field in the reader (or the N5KeyValueReader as a fallback)
+					Field cacheField;
+					try {
+						cacheField = reader.getClass().getDeclaredField("cache");
+					} catch (NoSuchFieldException e) {
+						cacheField = N5KeyValueReader.class.getDeclaredField("cache");
+					}
 					cacheField.setAccessible(true);
 
 					// Set the value of 'cache' to the one from writer.getCache()