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Posted to oak-commits@jackrabbit.apache.org by to...@apache.org on 2018/05/14 07:58:54 UTC

svn commit: r1831543 - in /jackrabbit/oak/branches/1.8/oak-upgrade: ./ src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/ src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/ src/test/java/org/apache/jackrabbit/oak/upgrade/ src/test/java/...

Author: tomekr
Date: Mon May 14 07:58:54 2018
New Revision: 1831543

URL: http://svn.apache.org/viewvc?rev=1831543&view=rev
Log:
OAK-7339: Introduce LoopbackBlobStore

Added:
    jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStore.java
    jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactory.java
      - copied, changed from r1831426, jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/MissingBlobStoreFactory.java
    jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactoryTest.java
    jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreTest.java
Removed:
    jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/MissingBlobStore.java
    jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/MissingBlobStoreFactory.java
Modified:
    jackrabbit/oak/branches/1.8/oak-upgrade/pom.xml
    jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/DatastoreArguments.java
    jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/CopyCheckpointsTest.java

Modified: jackrabbit/oak/branches/1.8/oak-upgrade/pom.xml
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/pom.xml?rev=1831543&r1=1831542&r2=1831543&view=diff
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/pom.xml (original)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/pom.xml Mon May 14 07:58:54 2018
@@ -212,6 +212,12 @@
       <version>${h2.version}</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>pl.pragmatists</groupId>
+      <artifactId>JUnitParams</artifactId>
+      <version>1.1.1</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <!-- Workaround for http://bugs.java.com/view_bug.do?bug_id=6550655 -->

Added: jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStore.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStore.java?rev=1831543&view=auto
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStore.java (added)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStore.java Mon May 14 07:58:54 2018
@@ -0,0 +1,112 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.jackrabbit.oak.upgrade.cli.blob;
+
+import org.apache.jackrabbit.oak.spi.blob.BlobOptions;
+import org.apache.jackrabbit.oak.spi.blob.BlobStore;
+
+import javax.annotation.Nonnull;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Utility BlobStore implementation to be used in tooling that can work with a
+ * FileStore without the need of the DataStore being present locally.
+ *
+ * Additionally instead of failing it tries to mimic and return blob reference
+ * passed in by <b>caller</b> by passing it back as a binary.
+ *
+ * Example: requesting <code>blobId = e7c22b994c59d9</code> it will return the
+ * <code>e7c22b994c59d9</code> text as a UTF-8 encoded binary file.
+ */
+public class LoopbackBlobStore implements BlobStore {
+
+    @Override
+    public String writeBlob(InputStream in) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public String writeBlob(InputStream in, BlobOptions options) throws IOException {
+        return writeBlob(in);
+    }
+
+    @Override
+    public int readBlob(String blobId, long pos, byte[] buff, int off,
+            int length) {
+        // Only a part of binary can be requested!
+        final int binaryLength = blobId.length();
+        checkBinaryOffsetInRange(pos, binaryLength);
+        final int effectiveSrcPos = Math.toIntExact(pos);
+        final int effectiveBlobLengthToBeRead = Math.min(
+                binaryLength - effectiveSrcPos, length);
+        checkForBufferOverflow(buff, off, effectiveBlobLengthToBeRead);
+        final byte[] blobIdBytes = getBlobIdStringAsByteArray(blobId);
+        System.arraycopy(blobIdBytes, effectiveSrcPos, buff, off,
+                effectiveBlobLengthToBeRead);
+        return effectiveBlobLengthToBeRead;
+    }
+
+    private void checkForBufferOverflow(final byte[] buff, final int off,
+                                        final int effectiveBlobLengthToBeRead) {
+        if (buff.length < effectiveBlobLengthToBeRead + off) {
+            // We cannot recover if buffer used to write is too small
+            throw new UnsupportedOperationException("Edge case: cannot fit " +
+                    "blobId in a buffer (buffer too small)");
+        }
+    }
+
+    private void checkBinaryOffsetInRange(final long pos, final int binaryLength) {
+        if (pos > binaryLength) {
+            throw new IllegalArgumentException(
+                    String.format("Offset %d out of range of %d", pos,
+                            binaryLength));
+        }
+    }
+
+    private byte[] getBlobIdStringAsByteArray(final String blobId) {
+        return blobId.getBytes(StandardCharsets.UTF_8);
+    }
+
+    @Override
+    public long getBlobLength(String blobId) throws IOException {
+        return blobId.length();
+    }
+
+    @Override
+    public InputStream getInputStream(String blobId) throws IOException {
+        checkNotNull(blobId);
+        return new ByteArrayInputStream(getBlobIdStringAsByteArray(blobId));
+    }
+
+    @Override
+    public String getBlobId(@Nonnull String reference) {
+        return checkNotNull(reference);
+    }
+
+    @Override
+    public String getReference(@Nonnull String blobId) {
+        return checkNotNull(blobId);
+    }
+}

Copied: jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactory.java (from r1831426, jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/MissingBlobStoreFactory.java)
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactory.java?p2=jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactory.java&p1=jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/MissingBlobStoreFactory.java&r1=1831426&r2=1831543&rev=1831543&view=diff
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/MissingBlobStoreFactory.java (original)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactory.java Mon May 14 07:58:54 2018
@@ -16,19 +16,21 @@
  */
 package org.apache.jackrabbit.oak.upgrade.cli.blob;
 
+import com.google.common.io.Closer;
 import org.apache.jackrabbit.oak.spi.blob.BlobStore;
 
-import com.google.common.io.Closer;
+import static com.google.common.base.Preconditions.checkNotNull;
 
-public class MissingBlobStoreFactory implements BlobStoreFactory {
+public class LoopbackBlobStoreFactory implements BlobStoreFactory {
 
     @Override
     public BlobStore create(Closer closer) {
-        return new MissingBlobStore();
+        checkNotNull(closer, "Closer object cannot be null");
+        return new LoopbackBlobStore();
     }
 
     @Override
     public String toString() {
-        return "MissingBlobStore";
+        return "LoopbackBlobStore";
     }
 }

Modified: jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/DatastoreArguments.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/DatastoreArguments.java?rev=1831543&r1=1831542&r2=1831543&view=diff
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/DatastoreArguments.java (original)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/DatastoreArguments.java Mon May 14 07:58:54 2018
@@ -23,7 +23,7 @@ import org.apache.jackrabbit.oak.upgrade
 import org.apache.jackrabbit.oak.upgrade.cli.blob.DummyBlobStoreFactory;
 import org.apache.jackrabbit.oak.upgrade.cli.blob.FileBlobStoreFactory;
 import org.apache.jackrabbit.oak.upgrade.cli.blob.FileDataStoreFactory;
-import org.apache.jackrabbit.oak.upgrade.cli.blob.MissingBlobStoreFactory;
+import org.apache.jackrabbit.oak.upgrade.cli.blob.LoopbackBlobStoreFactory;
 import org.apache.jackrabbit.oak.upgrade.cli.blob.S3DataStoreFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -110,7 +110,7 @@ public class DatastoreArguments {
         if (options.isSrcBlobStoreDefined()) {
             result = definedSrcBlob;
         } else if (blobMigrationCase == BlobMigrationCase.COPY_REFERENCES) {
-            result = new MissingBlobStoreFactory();
+            result = new LoopbackBlobStoreFactory();
         } else {
             result = new DummyBlobStoreFactory(); // embedded
         }
@@ -125,7 +125,7 @@ public class DatastoreArguments {
         } else if (blobMigrationCase == BlobMigrationCase.COPY_REFERENCES && (options.isSrcBlobStoreDefined() || storeArguments.getSrcType() == JCR2_DIR_XML)) {
             result = new ConstantBlobStoreFactory(srcBlobStore);
         } else if (blobMigrationCase == BlobMigrationCase.COPY_REFERENCES) {
-            result = new MissingBlobStoreFactory();
+            result = new LoopbackBlobStoreFactory();
         } else {
             result = new DummyBlobStoreFactory(); // embedded
         }

Modified: jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/CopyCheckpointsTest.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/CopyCheckpointsTest.java?rev=1831543&r1=1831542&r2=1831543&view=diff
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/CopyCheckpointsTest.java (original)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/CopyCheckpointsTest.java Mon May 14 07:58:54 2018
@@ -63,11 +63,11 @@ public class CopyCheckpointsTest extends
 
         BlobStoreContainer blob = new FileDataStoreContainer();
         params.add(new Object[]{
-                "Fails on missing blobstore",
+                "Without data store defined it always copies checkpoints",
                 new SegmentNodeStoreContainer(blob),
                 new SegmentNodeStoreContainer(blob),
                 asList(),
-                Result.EXCEPTION
+                Result.CHECKPOINTS_COPIED
         });
         params.add(new Object[]{
                 "Suppress the warning",

Added: jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactoryTest.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactoryTest.java?rev=1831543&view=auto
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactoryTest.java (added)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreFactoryTest.java Mon May 14 07:58:54 2018
@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.jackrabbit.oak.upgrade.cli.blob;
+
+import com.google.common.io.Closer;
+import org.apache.jackrabbit.oak.spi.blob.BlobStore;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static junit.framework.TestCase.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+@SuppressWarnings("UnusedLabel")
+public class LoopbackBlobStoreFactoryTest {
+
+    @Test(expected = NullPointerException.class)
+    public void cannotCreateLoopbackBlobStoreFactoryWithNullCloser() {
+        when: {
+            final LoopbackBlobStoreFactory factory = new LoopbackBlobStoreFactory();
+            factory.create(null);
+        }
+    }
+
+    @Test
+    public void canCreateLoopbackBlobStoreFactory() throws IOException {
+        when: {
+            final LoopbackBlobStoreFactory factory = new LoopbackBlobStoreFactory();
+            final Closer closer = Closer.create();
+            final BlobStore blobStore = factory.create(closer);
+
+            then: {
+                assertNotNull(blobStore);
+            }
+            and: {
+                closer.close();
+            }
+        }
+    }
+
+    @Test
+    public void canGetNameFromLoopbackBlobStoreFactory() {
+        when: {
+            final LoopbackBlobStoreFactory factory = new LoopbackBlobStoreFactory();
+
+            then: {
+                assertEquals("LoopbackBlobStore", factory.toString());
+            }
+        }
+    }
+
+}

Added: jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreTest.java
URL: http://svn.apache.org/viewvc/jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreTest.java?rev=1831543&view=auto
==============================================================================
--- jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreTest.java (added)
+++ jackrabbit/oak/branches/1.8/oak-upgrade/src/test/java/org/apache/jackrabbit/oak/upgrade/cli/blob/LoopbackBlobStoreTest.java Mon May 14 07:58:54 2018
@@ -0,0 +1,360 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.jackrabbit.oak.upgrade.cli.blob;
+
+import junitparams.JUnitParamsRunner;
+import junitparams.Parameters;
+import org.apache.commons.io.IOUtils;
+import org.apache.jackrabbit.oak.spi.blob.BlobOptions;
+import org.apache.jackrabbit.oak.spi.blob.BlobStore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertNotNull;
+
+@SuppressWarnings("UnusedLabel")
+@RunWith(JUnitParamsRunner.class)
+public class LoopbackBlobStoreTest {
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void writingBinariesIsNotSupported() throws IOException {
+        given:
+        {
+            final BlobStore blobStore = new LoopbackBlobStore();
+
+            when:
+            {
+                final String test = "Test";
+                blobStore.writeBlob(adaptToUtf8InputStream(test));
+            }
+        }
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void writingBinariesWithBlobOptsIsNotSupported() throws IOException {
+        given:
+        {
+            final BlobStore blobStore = new LoopbackBlobStore();
+            final BlobOptions blobOptions = new BlobOptions();
+
+            when:
+            {
+                blobStore.writeBlob(adaptToUtf8InputStream("Test"),
+                        blobOptions);
+            }
+        }
+    }
+
+
+    @Test
+    @Parameters(method = "blobIds")
+    public void getBlobIdShouldReturnTheSameValuePassedExceptOfNull(
+            final String blobId) {
+        given:
+        {
+            final BlobStore blobStore = new LoopbackBlobStore();
+            expect:
+            {
+                assertEquals(blobId, blobStore.getBlobId(blobId));
+            }
+        }
+    }
+
+
+    @SuppressWarnings("ConstantConditions")
+    @Test(expected = NullPointerException.class)
+    public void getBlobIdShouldThrowAnExceptionWhenNullIsPassed() {
+        given:
+        {
+            final BlobStore blobStore = new LoopbackBlobStore();
+            when:
+            {
+                blobStore.getBlobId(null);
+            }
+        }
+    }
+
+
+    @Test
+    @Parameters(method = "blobIds")
+    public void getReferenceShouldReturnTheSameValuePassedExceptOfNull(
+            final String blobId) {
+        given:
+        {
+            final BlobStore blobStore = new LoopbackBlobStore();
+            where:
+            {
+                expect:
+                {
+                    assertEquals(blobId, blobStore.getReference(blobId));
+                }
+            }
+        }
+    }
+
+    @SuppressWarnings("ConstantConditions")
+    @Test(expected = NullPointerException.class)
+    public void getReferenceShouldThrowAnExceptionWhenNullIsPassed() {
+        given:
+        {
+            final BlobStore blobStore = new LoopbackBlobStore();
+            when:
+            {
+                blobStore.getReference(null);
+            }
+        }
+    }
+
+    @Test
+    @Parameters(method = "blobIds")
+    public void getBlobLengthShouldAlwaysReturnRealLengthOfBlobThatWillBeReturned(
+            final String blobId) throws IOException {
+        given:
+        {
+            final BlobStore store = new LoopbackBlobStore();
+            expect:
+            {
+                assertEquals(blobId.getBytes().length, store.getBlobLength(blobId));
+            }
+        }
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void getBlobLengthShouldAlwaysThrowAnExceptionWhenNullBlobIdIsPassed()
+            throws IOException {
+        given:
+        {
+            final BlobStore store = new LoopbackBlobStore();
+            when:
+            {
+                store.getBlobLength(null);
+            }
+        }
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void getInputStreamShouldAlwaysThrowAnExceptionWhenNullBlobIdIsPassed()
+            throws IOException {
+        given:
+        {
+            final BlobStore store = new LoopbackBlobStore();
+            when:
+            {
+                store.getInputStream(null);
+            }
+        }
+    }
+
+    @Test
+    @Parameters(method = "blobIds")
+    public void shouldAlwaysReturnStreamOfRequestedBlobIdUtf8BinRepresentation(
+            final String blobId) throws IOException {
+        given:
+        {
+            final String encoding = "UTF-8";
+            final BlobStore store = new LoopbackBlobStore();
+            when:
+            {
+                final InputStream inputStream = store.getInputStream(blobId);
+                then:
+                {
+                    assertNotNull(inputStream);
+                }
+                and:
+                {
+                    final String actualInputStreamAsString = IOUtils.toString(
+                            inputStream, encoding);
+                    then:
+                    {
+                        assertEquals(actualInputStreamAsString, blobId);
+                    }
+                }
+            }
+        }
+    }
+
+    @Test
+    @Parameters(method = "blobIdsReads")
+    public void shouldAlwaysFillBufferWithRequestedBlobIdUtf8BinRepresentation(
+            final String blobId,
+            int offsetToRead,
+            int bufSize,
+            int bufOffset,
+            int lengthToRead,
+            final String expectedBufferContent,
+            final int expectedNumberOfBytesRead) throws IOException {
+        given:
+        {
+            final String encoding = "UTF-8";
+            final BlobStore blobStore = new LoopbackBlobStore();
+            final byte[] buffer = new byte[bufSize];
+            when:
+            {
+                final int numberOfBytesRead = blobStore.readBlob(
+                        blobId, offsetToRead, buffer, bufOffset, lengthToRead);
+                and:
+                {
+                    final String actualInputStreamAsString = IOUtils.toString(
+                            buffer, encoding);
+                    then:
+                    {
+                        assertEquals(numberOfBytesRead,
+                                expectedNumberOfBytesRead);
+                        assertEquals(expectedBufferContent,
+                                encodeBufferFreeSpace(actualInputStreamAsString));
+                    }
+                }
+            }
+        }
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    @Parameters(method = "blobIdsFailedBufferReadsCases")
+    public void getInputStreamShouldAlwaysReturnExceptionIfBufferTooSmall(
+            final String blobId,
+            int offsetToRead,
+            int bufSize,
+            int bufOffset,
+            int lengthToRead) throws IOException {
+        given:
+        {
+            final BlobStore store = new LoopbackBlobStore();
+            final byte[] buffer = new byte[bufSize];
+            when:
+            {
+                store.readBlob(
+                        blobId, offsetToRead, buffer, bufOffset, lengthToRead);
+            }
+        }
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    @Parameters(method = "blobIdsFailedOffsetReadsCases")
+    public void getInputStreamShouldAlwaysReturnExceptionIfBinaryOffsetIsBad(
+            final String blobId,
+            int offsetToRead,
+            int bufSize,
+            int bufOffset,
+            int lengthToRead) throws IOException {
+        given:
+        {
+            final BlobStore store = new LoopbackBlobStore();
+            final byte[] buffer = new byte[bufSize];
+            when:
+            {
+                store.readBlob(
+                        blobId, offsetToRead, buffer, bufOffset, lengthToRead);
+            }
+        }
+    }
+
+    @SuppressWarnings("unused")
+    private Object blobIdsReads() {
+        return new Object[]{
+                //blobId, offsetToRead, bufSize, bufOffset, lengthToRead, expectedBufferContent, expectedNumOfBytesRead
+                new Object[]{
+                        "",                                 0,  0, 0,   0, "",                      0},
+                new Object[]{
+                        "",                                 0,  0, 0,   1, "",                      0},
+                new Object[]{
+                        "IDX1",                             0,  4, 0,   4, "IDX1",                  4},
+                new Object[]{
+                        "IDX1",                             4,  0, 0,   4, "",                      0},
+                new Object[]{
+                        "IDX1",                             4,  4, 0,   4, "####",                  0},
+                new Object[]{
+                        "IDX1",                             0,  5, 0,   4, "IDX1#",                 4},
+                new Object[]{
+                        "IDX1",                             1,  4, 0,   3, "DX1#",                  3},
+                new Object[]{
+                        "IDX1",                             1,  4, 0,   4, "DX1#",                  3},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZYZYYXYZYZYXYZQ", 10, 20, 3,  10, "###XXXXYYZYZY#######", 10},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              10, 20, 3,  10, "###XXXXYYZY#########",  8},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              10, 20, 3,  10, "###XXXXYYZY#########",  8},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              10, 11, 3,  10, "###XXXXYYZY",           8},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              10, 11, 2,  10, "##XXXXYYZY#",           8},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              10, 11, 1,  10, "#XXXXYYZY##",           8},
+        };
+    }
+
+    @SuppressWarnings("unused")
+    private Object blobIdsFailedBufferReadsCases() {
+        return new Object[]{
+                //blobId, offsetToRead, bufferSize, bufferOffset, lengthToRead
+                new Object[]{
+                        " ",                                0,  0,  0,   1},
+                new Object[]{
+                        "IDX1",                             0,  3,  0,   4},
+                new Object[]{
+                        "IDX1",                             1,  3,  2,   3},
+                new Object[]{
+                        "IDX1",                             1,  2,  0,   3},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              10,  0, 30,  10},
+        };
+    }
+
+    @SuppressWarnings("unused")
+    private Object blobIdsFailedOffsetReadsCases() {
+        return new Object[]{
+                //blobId, offsetToRead, bufferSize, bufferOffset, lengthToRead
+                new Object[]{
+                        "",                                 1,  50, 0,   0},
+                new Object[]{
+                        "IDX1",                             5,  50, 0,   3},
+                new Object[]{
+                        "IDX1",                             6,  50, 0,   4},
+                new Object[]{
+                        "ID2XXXXXXXXXXXYYZY",              30,  50, 1,  10},
+        };
+    }
+
+
+    @SuppressWarnings("unused")
+    private Object blobIds() {
+        return new Object[]{
+                new Object[]{""},
+                new Object[]{"IDX1"},
+                new Object[]{"ID2XXXXXXXXXXXYYZYZYYXYZYZYXYZQ"},
+                new Object[]{"ABCQ"}
+        };
+    }
+
+    private String encodeBufferFreeSpace(final String actualInputStreamAsString) {
+        return actualInputStreamAsString.replace('\0', '#');
+    }
+
+    private InputStream adaptToUtf8InputStream(final String string)
+            throws IOException {
+        return IOUtils.toInputStream(string,
+                "UTF-8");
+    }
+
+}
+