feat: add filter transformation for TimestampBasedKeyGenerator partition pruning

crates/core/src/keygen/mod.rs

@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+//! Key generator implementations for transforming user filters to partition filters.
+
+pub mod timestamp_based;
+
+use crate::expr::filter::Filter;
+use crate::Result;
+
+/// Trait for key generators that can transform user filters on data columns
+/// to filters on partition path columns.
+pub trait KeyGeneratorFilterTransformer {
+    /// Returns the source field name that this key generator operates on.
+    /// For example, "event_timestamp" or "ts_str".
+    fn source_field(&self) -> &str;
+
+    /// Transforms a filter on the source field to one or more filters on partition fields.
+    ///
+    /// # Arguments
+    /// * `filter` - The user-provided filter on the source data column
+    ///
+    /// # Returns
+    /// A vector of filters on partition path fields that are equivalent to the input filter.
+    ///
+    /// # Example
+    /// ```text
+    /// Input:  Filter { field: "event_timestamp", op: ">=", value: "2024-01-25T00:00:00.000Z" }
+    /// Output: [
+    ///   Filter { field: "year", op: ">=", value: "2024" },
+    ///   Filter { field: "month", op: ">=", value: "01" },
+    ///   Filter { field: "day", op: ">=", value: "25" },
+    /// ]
+    /// ```
+    fn transform_filter(&self, filter: &Filter) -> Result<Vec<Filter>>;
+}