HBASE-22580 Add a table attribute to make user scan snapshot feature …

…configurable for table

hbase-client/src/main/java/org/apache/hadoop/hbase/HTableDescriptor.java

@@ -527,6 +527,16 @@ public boolean hasFamily(final byte [] familyName) {
     return delegatee.hasColumnFamily(familyName);
   }
 
+  /**
+   * Check if user scan snapshot enable flag of the table is true. If flag is false then
+   * SnapshotScannerHDFSAclController won't handle HDFS acls for users with table read permission
+   * @return true if user scan snapshot is enabled for this table
+   */
+  @Override
+  public boolean isUserScanSnapshotEnabled() {
+    return delegatee.isUserScanSnapshotEnabled();
+  }
+
   /**
    * @return Name of this table and then a map of all of the column family
    * descriptors.

hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptor.java

@@ -345,4 +345,11 @@ default boolean matchReplicationScope(boolean enabled) {
     }
     return !enabled;
   }
+
+  /**
+   * Check if user scan snapshot enable flag of the table is true. If flag is false then
+   * SnapshotScannerHDFSAclController won't handle HDFS acls for users with table read permission
+   * @return true if user scan snapshot is enabled for this table
+   */
+  boolean isUserScanSnapshotEnabled();
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java

@@ -188,6 +188,11 @@ public class TableDescriptorBuilder {
   private static final Bytes PRIORITY_KEY
           = new Bytes(Bytes.toBytes(PRIORITY));
 
+  @InterfaceAudience.Private
+  public static final String USER_SCAN_SNAPSHOT_ENABLED = "USER_SCAN_SNAPSHOT_ENABLED";
+  private static final Bytes USER_SCAN_SNAPSHOT_ENABLED_KEY =
+      new Bytes(Bytes.toBytes(USER_SCAN_SNAPSHOT_ENABLED));
+
   /**
    * Relative priority of the table used for rpc scheduling
    */
@@ -537,6 +542,11 @@ public TableDescriptorBuilder setReplicationScope(int scope) {
     return this;
   }
 
+  public TableDescriptorBuilder setUserScanSnapshotEnabled(boolean isEnable) {
+    desc.setUserScanSnapshotEnabled(isEnable);
+    return this;
+  }
+
   public TableDescriptor build() {
     return new ModifyableTableDescriptor(desc);
   }
@@ -1074,6 +1084,27 @@ public boolean hasColumnFamily(final byte[] familyName) {
       return families.containsKey(familyName);
     }
 
+    /**
+     * Setting the user scan snapshot enable flag.
+     *
+     * @param isEnabled True if enable user scan snapshot.
+     * @return the modifyable TD
+     */
+    public ModifyableTableDescriptor setUserScanSnapshotEnabled(boolean isEnabled) {
+      return setValue(USER_SCAN_SNAPSHOT_ENABLED_KEY, Boolean.toString(isEnabled));
+    }
+
+    /**
+     * Check if user scan snapshot enable flag of the table is true. If flag is false then
+     * SnapshotScannerHDFSAclController won't handle HDFS acls for users with table read permission
+     *
+     * @return true if user scan snapshot is enabled for this table
+     */
+    @Override
+    public boolean isUserScanSnapshotEnabled() {
+      return getOrDefault(USER_SCAN_SNAPSHOT_ENABLED_KEY, Boolean::valueOf, false);
+    }
+
     /**
      * @return Name of this table and then a map of all of the column family descriptors.
      */

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/PermissionStorage.java

@@ -508,6 +508,11 @@ public static ListMultimap<String, UserPermission> getNamespacePermissions(Confi
       false);
   }
 
+  public static ListMultimap<String, UserPermission> getGlobalPermissions(Configuration conf)
+      throws IOException {
+    return getPermissions(conf, null, null, null, null, null, false);
+  }
+
   /**
    * Reads user permission assignments stored in the <code>l:</code> column family of the first
    * table row in <code>_acl_</code>.