Format cassandra collection types as JSON

By formatting collection types as JSON, we can use Presto's JSON
functions to extract values.

presto-cassandra/src/main/java/com/facebook/presto/cassandra/CassandraType.java

@@ -22,6 +22,7 @@
 import com.facebook.presto.spi.type.DoubleType;
 import com.facebook.presto.spi.type.Type;
 import com.facebook.presto.spi.type.VarcharType;
+import com.google.common.annotations.VisibleForTesting;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -225,8 +226,7 @@ private static String buildListValue(Row row, int i, CassandraType elemType)
         return buildArrayValue(row.getList(i, elemType.javaType), elemType);
     }
 
-    private static String buildMapValue(Row row, int i, CassandraType keyType,
-            CassandraType valueType)
+    private static String buildMapValue(Row row, int i, CassandraType keyType, CassandraType valueType)
     {
         StringBuilder sb = new StringBuilder();
         sb.append("{");
@@ -242,7 +242,8 @@ private static String buildMapValue(Row row, int i, CassandraType keyType,
         return sb.toString();
     }
 
-    private static String buildArrayValue(Collection<?> collection, CassandraType elemType)
+    @VisibleForTesting
+    static String buildArrayValue(Collection<?> collection, CassandraType elemType)
     {
         StringBuilder sb = new StringBuilder();
         sb.append("[");
@@ -319,11 +320,11 @@ private static String objectToString(Object object, CassandraType elemType)
             case TIMESTAMP:
             case INET:
             case VARINT:
-                return CassandraCqlUtils.quoteStringLiteral(object.toString());
+                return CassandraCqlUtils.quoteStringLiteralForJson(object.toString());
 
             case BLOB:
             case CUSTOM:
-                return CassandraCqlUtils.quoteStringLiteral(Bytes.toHexString((ByteBuffer) object));
+                return CassandraCqlUtils.quoteStringLiteralForJson(Bytes.toHexString((ByteBuffer) object));
 
             case INT:
             case BIGINT:

presto-cassandra/src/main/java/com/facebook/presto/cassandra/util/CassandraCqlUtils.java

@@ -19,6 +19,7 @@
 import com.facebook.presto.cassandra.CassandraColumnHandle;
 import com.facebook.presto.cassandra.CassandraTableHandle;
 import com.facebook.presto.spi.ConnectorColumnHandle;
+import com.fasterxml.jackson.core.io.JsonStringEncoder;
 
 import java.util.Arrays;
 import java.util.HashSet;
@@ -87,6 +88,11 @@ public static String quoteStringLiteral(String string)
         return "'" + string.replace("'", "''") + "'";
     }
 
+    public static String quoteStringLiteralForJson(String string)
+    {
+        return '"' + new String(JsonStringEncoder.getInstance().quoteAsUTF8(string)) + '"';
+    }
+
     public static void appendSelectColumns(StringBuilder stringBuilder, List<? extends ConnectorColumnHandle> columns)
     {
         appendSelectColumns(stringBuilder, columns, true);

presto-cassandra/src/test/java/com/facebook/presto/cassandra/TestCassandraType.java

@@ -0,0 +1,58 @@
+/*
+ * Licensed 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 com.facebook.presto.cassandra;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.Lists;
+import org.testng.annotations.Test;
+
+import java.io.IOException;
+
+import static org.testng.Assert.assertTrue;
+
+public class TestCassandraType
+{
+    @Test
+    public void testJsonMapEncoding()
+    {
+        assertTrue(isValidJson(CassandraType.buildArrayValue(Lists.newArrayList("one", "two", "three\""), CassandraType.VARCHAR)));
+        assertTrue(isValidJson(CassandraType.buildArrayValue(Lists.newArrayList(1, 2, 3), CassandraType.INT)));
+        assertTrue(isValidJson(CassandraType.buildArrayValue(Lists.newArrayList(100000L, 200000000L, 3000000000L), CassandraType.BIGINT)));
+        assertTrue(isValidJson(CassandraType.buildArrayValue(Lists.newArrayList(1.0, 2.0, 3.0), CassandraType.DOUBLE)));
+    }
+
+    private static void continueWhileNotNull(JsonParser parser, JsonToken token)
+            throws IOException
+    {
+        if (token != null) {
+            continueWhileNotNull(parser, parser.nextToken());
+        }
+    }
+
+    private static boolean isValidJson(String json)
+    {
+        boolean valid = false;
+        try {
+            JsonParser parser = new ObjectMapper().getFactory()
+                    .createJsonParser(json);
+            continueWhileNotNull(parser, parser.nextToken());
+            valid = true;
+        }
+        catch (IOException ignored) {
+        }
+        return valid;
+    }
+}

presto-cassandra/src/test/java/com/facebook/presto/cassandra/util/TestCassandraCqlUtils.java

@@ -21,6 +21,7 @@
 import java.util.List;
 
 import static com.facebook.presto.cassandra.util.CassandraCqlUtils.quoteStringLiteral;
+import static com.facebook.presto.cassandra.util.CassandraCqlUtils.quoteStringLiteralForJson;
 import static com.facebook.presto.cassandra.util.CassandraCqlUtils.validColumnName;
 import static com.facebook.presto.cassandra.util.CassandraCqlUtils.validSchemaName;
 import static com.facebook.presto.cassandra.util.CassandraCqlUtils.validTableName;
@@ -59,6 +60,14 @@ public void testQuote()
         assertEquals("'Presto''s'", quoteStringLiteral("Presto's"));
     }
 
+    @Test
+    public void testQuoteJson()
+    {
+        assertEquals("\"foo\"", quoteStringLiteralForJson("foo"));
+        assertEquals("\"Presto's\"", quoteStringLiteralForJson("Presto's"));
+        assertEquals("\"xx\\\"xx\"", quoteStringLiteralForJson("xx\"xx"));
+    }
+
     @Test
     public void testAppendSelectColumns()
     {