Merge branch 'cassandra-2.1' into trunk

CHANGES.txt

@@ -142,6 +142,7 @@
  * Fix sstableupgrade throws exception (CASSANDRA-8688)
  * Fix hang when repairing empty keyspace (CASSANDRA-8694)
 Merged from 2.0:
+ * Add support for UPDATE ... IF EXISTS (CASSANDRA-8610)
  * Fix reversal of list prepends (CASSANDRA-8733)
  * Prevent non-zero default_time_to_live on tables with counters
    (CASSANDRA-8678)

pylib/cqlshlib/cql3handling.py

@@ -766,7 +766,7 @@ syntax_rules += r'''
                                   ( "AND" [updateopt]=<usingOption> )* )?
                         "SET" <assignment> ( "," <assignment> )*
                         "WHERE" <whereClause>
-                        ( "IF" <conditions> )?
+                        ( "IF" ( "EXISTS" | <conditions> ))?
                     ;
 <assignment> ::= updatecol=<cident>
                     ( "=" update_rhs=( <term> | <cident> )

pylib/cqlshlib/helptopics.py

@@ -562,7 +562,8 @@ class CQL3HelpTopics(CQLHelpTopics):
         UPDATE [<keyspace>.]<columnFamily>
                               [USING [TIMESTAMP <timestamp>]
                                 [AND TTL <timeToLive>]]
-               SET name1 = value1, name2 = value2 WHERE <keycol> = keyval;
+               SET name1 = value1, name2 = value2 WHERE <keycol> = keyval
+               [IF EXISTS];
 
         An UPDATE is used to write one or more columns to a record in a table.
         No results are returned. The record's primary key must be completely

src/java/org/apache/cassandra/cql3/Cql.g

@@ -387,18 +387,20 @@ updateStatement returns [UpdateStatement.ParsedUpdate expr]
     @init {
         Attributes.Raw attrs = new Attributes.Raw();
         List<Pair<ColumnIdentifier.Raw, Operation.RawUpdate>> operations = new ArrayList<Pair<ColumnIdentifier.Raw, Operation.RawUpdate>>();
+        boolean ifExists = false;
     }
     : K_UPDATE cf=columnFamilyName
       ( usingClause[attrs] )?
       K_SET columnOperation[operations] (',' columnOperation[operations])*
       K_WHERE wclause=whereClause
-      ( K_IF conditions=updateConditions )?
+      ( K_IF ( K_EXISTS { ifExists = true; } | conditions=updateConditions ))?
       {
           return new UpdateStatement.ParsedUpdate(cf,
                                                   attrs,
                                                   operations,
                                                   wclause,
-                                                  conditions == null ? Collections.<Pair<ColumnIdentifier.Raw, ColumnCondition.Raw>>emptyList() : conditions);
+                                                  conditions == null ? Collections.<Pair<ColumnIdentifier.Raw, ColumnCondition.Raw>>emptyList() : conditions,
+                                                  ifExists);
      }
     ;
 

src/java/org/apache/cassandra/cql3/statements/UpdateStatement.java

@@ -198,14 +198,16 @@ public class UpdateStatement extends ModificationStatement
          * @param attrs additional attributes for statement (timestamp, timeToLive)
          * @param updates a map of column operations to perform
          * @param whereClause the where clause
-         */
+         * @param ifExists flag to check if row exists
+         * */
         public ParsedUpdate(CFName name,
                             Attributes.Raw attrs,
                             List<Pair<ColumnIdentifier.Raw, Operation.RawUpdate>> updates,
                             List<Relation> whereClause,
-                            List<Pair<ColumnIdentifier.Raw, ColumnCondition.Raw>> conditions)
+                            List<Pair<ColumnIdentifier.Raw, ColumnCondition.Raw>> conditions,
+                            boolean ifExists)
         {
-            super(name, attrs, conditions, false, false);
+            super(name, attrs, conditions, false, ifExists);
             this.updates = updates;
             this.whereClause = whereClause;
         }