feat: Add CLP UDFs with query rewriting support

presto-clp/pom.xml

@@ -140,5 +140,22 @@
             <artifactId>commons-io</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.facebook.presto</groupId>
+            <artifactId>presto-tests</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>com.facebook.presto</groupId>
+            <artifactId>presto-main-base</artifactId>
+            <type>test-jar</type>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>com.facebook.presto</groupId>
+            <artifactId>presto-expressions</artifactId>
+        </dependency>
     </dependencies>
 </project>

presto-clp/src/main/java/com/facebook/presto/plugin/clp/ClpFunctions.java

@@ -0,0 +1,105 @@
+/*
+ * 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.plugin.clp;
+
+import com.facebook.presto.common.block.Block;
+import com.facebook.presto.common.block.BlockBuilder;
+import com.facebook.presto.common.type.StandardTypes;
+import com.facebook.presto.spi.function.Description;
+import com.facebook.presto.spi.function.ScalarFunction;
+import com.facebook.presto.spi.function.SqlType;
+import io.airlift.slice.Slice;
+import io.airlift.slice.Slices;
+
+import static com.facebook.presto.common.type.VarcharType.VARCHAR;
+
+public final class ClpFunctions
+{
+    private ClpFunctions()
+    {
+    }
+
+    @ScalarFunction(value = "CLP_GET_INT", deterministic = false)
+    @Description("Retrieves an integer value corresponding to the given JSON path.")
+    @SqlType(StandardTypes.BIGINT)
+    public static long clpGetInt(@SqlType(StandardTypes.VARCHAR) Slice jsonPath)
+    {
+        return 0;
+    }
+
+    @ScalarFunction(value = "CLP_GET_FLOAT", deterministic = false)
+    @Description("Retrieves a floating point value corresponding to the given JSON path.")
+    @SqlType(StandardTypes.DOUBLE)
+    public static double clpGetFloat(@SqlType(StandardTypes.VARCHAR) Slice jsonPath)
+    {
+        return 0.0;
+    }
+
+    @ScalarFunction(value = "CLP_GET_BOOL", deterministic = false)
+    @Description("Retrieves a boolean value corresponding to the given JSON path.")
+    @SqlType(StandardTypes.BOOLEAN)
+    public static boolean clpGetBool(@SqlType(StandardTypes.VARCHAR) Slice jsonPath)
+    {
+        return false;
+    }
+
+    @ScalarFunction(value = "CLP_GET_STRING", deterministic = false)
+    @Description("Retrieves a string value corresponding to the given JSON path.")
+    @SqlType(StandardTypes.VARCHAR)
+    public static Slice clpGetString(@SqlType(StandardTypes.VARCHAR) Slice jsonPath)
+    {
+        return Slices.EMPTY_SLICE;
+    }
+
+    @ScalarFunction(value = "CLP_GET_STRING_ARRAY", deterministic = false)
+    @Description("Retrieves an array value corresponding to the given JSON path and converts each element into a string.")
+    @SqlType("ARRAY(VARCHAR)")
+    public static Block clpGetStringArray(@SqlType(StandardTypes.VARCHAR) Slice jsonPath)
+    {
+        BlockBuilder blockBuilder = VARCHAR.createBlockBuilder(null, 0);
+        return blockBuilder.build();
+    }
+
+    @ScalarFunction(value = "CLP_WILDCARD_STRING_COLUMN", deterministic = false)
+    @Description("Used in filter expressions to allow comparisons with any string column in the log record.")
+    @SqlType(StandardTypes.VARCHAR)
+    public static Slice clpWildcardStringColumn()
+    {
+        return Slices.EMPTY_SLICE;
+    }
+
+    @ScalarFunction(value = "CLP_WILDCARD_INT_COLUMN", deterministic = false)
+    @Description("Used in filter expressions to allow comparisons with any integer column in the log record.")
+    @SqlType(StandardTypes.BIGINT)
+    public static long clpWildcardIntColumn()
+    {
+        return 0;
+    }
+
+    @ScalarFunction(value = "CLP_WILDCARD_FLOAT_COLUMN", deterministic = false)
+    @Description("Used in filter expressions to allow comparisons with any floating point column in the log record.")
+    @SqlType(StandardTypes.DOUBLE)
+    public static double clpWildcardFloatColumn()
+    {
+        return 0.0;
+    }
+
+    @ScalarFunction(value = "CLP_WILDCARD_BOOL_COLUMN", deterministic = false)
+    @Description("Used in filter expressions to allow comparisons with any boolean column in the log record.")
+    @SqlType(StandardTypes.BOOLEAN)
+    public static boolean clpWildcardBoolColumn()
+    {
+        return false;
+    }
+}

presto-clp/src/main/java/com/facebook/presto/plugin/clp/ClpMetadataFilterProvider.java

@@ -84,11 +84,16 @@ public class ClpMetadataFilterProvider
     public ClpMetadataFilterProvider(ClpConfig config)
     {
         requireNonNull(config, "config is null");
+        String configPath = config.getMetadataFilterConfig();
+        if (configPath == null || configPath.isEmpty()) {
+            filterMap = ImmutableMap.of();
+            return;
+        }
 
         ObjectMapper mapper = new ObjectMapper();
         try {
             filterMap = mapper.readValue(
-                    new File(config.getMetadataFilterConfig()),
+                    new File(configPath),
                     new TypeReference<Map<String, List<Filter>>>() {});
         }
         catch (IOException e) {