HDDS-7789. [Snapshot] Provide API for snapDiff from OFS.

hadoop-hdds/common/src/main/java/org/apache/hadoop/ozone/OzoneConfigKeys.java

@@ -641,7 +641,11 @@ public final class OzoneConfigKeys {
       TimeDuration.valueOf(150, TimeUnit.SECONDS);
   public static final String OZONE_SCM_CLOSE_CONTAINER_WAIT_DURATION =
       "ozone.scm.close.container.wait.duration";
-
+
+  public static final String OZONE_OM_SNAPDIFF_MAX_PAGE_SIZE =
+      "ozone.om.snapdiff.max.page.size";
+  public static final int OZONE_OM_SNAPDIFF_MAX_PAGE_SIZE_DEFAULT = 1000;
+
   /**
    * There is no need to instantiate this class.
    */

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -3700,4 +3700,12 @@
       Buffer size for SST Dumptool Pipe which would be used for computing snapdiff when native library is enabled.
     </description>
   </property>
+  <property>
+    <name>ozone.om.snapdiff.max.page.size</name>
+    <value>1000</value>
+    <tag>OZONE, OM</tag>
+    <description>
+      Maximum number of entries that a single snapDiff RPC would return.
+    </description>
+  </property>
 </configuration>

hadoop-ozone/common/pom.xml

@@ -107,6 +107,10 @@ https://maven.apache.org/xsd/maven-4.0.0.xsd">
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-params</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.apache.hadoop</groupId>
+      <artifactId>hadoop-hdfs-client</artifactId>
+    </dependency>
   </dependencies>
 
   <build>

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/protocolPB/OzoneManagerProtocolClientSideTranslatorPB.java

@@ -191,7 +191,7 @@
 import org.apache.hadoop.ozone.security.proto.SecurityProtos.CancelDelegationTokenRequestProto;
 import org.apache.hadoop.ozone.security.proto.SecurityProtos.GetDelegationTokenRequestProto;
 import org.apache.hadoop.ozone.security.proto.SecurityProtos.RenewDelegationTokenRequestProto;
-import org.apache.hadoop.ozone.snapshot.SnapshotDiffReport;
+import org.apache.hadoop.ozone.snapshot.SnapshotDiffReportOzone;
 import org.apache.hadoop.ozone.snapshot.SnapshotDiffResponse;
 import org.apache.hadoop.ozone.snapshot.SnapshotDiffResponse.JobStatus;
 import org.apache.hadoop.ozone.upgrade.UpgradeFinalizer;
@@ -1228,8 +1228,8 @@ public SnapshotDiffResponse snapshotDiff(String volumeName,
     OzoneManagerProtocolProtos.SnapshotDiffResponse diffResponse =
         omResponse.getSnapshotDiffResponse();
 
-    return new SnapshotDiffResponse(
-        SnapshotDiffReport.fromProtobuf(diffResponse.getSnapshotDiffReport()),
+    return new SnapshotDiffResponse(SnapshotDiffReportOzone.fromProtobuf(
+        diffResponse.getSnapshotDiffReport()),
         JobStatus.fromProtobuf(diffResponse.getJobStatus()),
         diffResponse.getWaitTimeInMs());
   }