Add unit tests for IndexSelectPlan

src/index/plan/index_select_plan.rs

@@ -57,3 +57,109 @@ impl PlanControl for IndexSelectPlan {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::index::IndexControl;
+    use crate::{
+        db::SimpleDB,
+        record::{layout::Layout, schema::Schema},
+        scan::{table_scan::TableScan, RecordId, Scan, ScanControl},
+    };
+    use std::sync::{Arc, Mutex};
+
+    #[test]
+    fn test_index_select_plan_open_and_stats() -> Result<(), TransactionError> {
+        let temp_dir = tempfile::tempdir().unwrap().into_path().join("directory");
+        let block_size = 1024;
+        let num_buffers = 256;
+        let db = SimpleDB::new(temp_dir, block_size, num_buffers)?;
+
+        let tx = Arc::new(Mutex::new(db.new_transaction()?));
+
+        let mut schema = Schema::new();
+        schema.add_i32_field("A");
+        schema.add_string_field("B", 20);
+        let layout = Arc::new(Layout::new(schema));
+
+        let table_name = "test_table";
+        let index_name = "test_index";
+        {
+            let mut mm = db.metadata_manager.lock().unwrap();
+            mm.create_table(table_name, &layout.schema, tx.clone())?;
+            mm.create_index(index_name, table_name, "B", tx.clone())?;
+        }
+
+        let mut table_scan = TableScan::new(tx.clone(), table_name, layout.clone())?;
+        let mut index = db
+            .metadata_manager
+            .lock()
+            .unwrap()
+            .get_index_info(table_name, tx.clone())?
+            .get("B")
+            .unwrap()
+            .open()?;
+
+        let mut expected = Vec::new();
+        table_scan.before_first()?;
+        for i in 0..30 {
+            table_scan.insert()?;
+            table_scan.set_i32("A", i)?;
+            let val = (i % 4).to_string();
+            table_scan.set_string("B", &val)?;
+            index.insert(
+                &Value::String(val.clone()),
+                &RecordId::from(table_scan.get_record_pointer()),
+            )?;
+            if val == "2" {
+                expected.push(i);
+            }
+        }
+        drop(index);
+        drop(table_scan);
+        tx.lock().unwrap().commit()?;
+
+        let tx = Arc::new(Mutex::new(db.new_transaction()?));
+        db.metadata_manager
+            .lock()
+            .unwrap()
+            .stat_manager
+            .lock()
+            .unwrap()
+            .refresh_statistics(tx.clone())?;
+
+        let table_plan = TablePlan::new(tx.clone(), table_name, db.metadata_manager.clone())?;
+        let index_info = db
+            .metadata_manager
+            .lock()
+            .unwrap()
+            .get_index_info(table_name, tx.clone())?
+            .get("B")
+            .unwrap()
+            .clone();
+
+        let mut plan =
+            IndexSelectPlan::new(table_plan, &index_info, &Value::String("2".to_string()));
+        let mut scan = match plan.open(tx.clone())? {
+            Scan::IndexSelectScan(s) => s,
+            _ => panic!("Expected IndexSelectScan"),
+        };
+
+        scan.before_first()?;
+        let mut actual = Vec::new();
+        while scan.next()? {
+            actual.push(scan.get_i32("A")?.unwrap());
+        }
+        actual.sort();
+        expected.sort();
+        assert_eq!(actual, expected);
+
+        assert!(plan.get_num_accessed_blocks() > 0);
+        assert!(plan.get_num_output_records() > 0);
+        assert!(plan.num_distinct_values("B") >= 1);
+        assert!(plan.schema().has_field("A"));
+
+        Ok(())
+    }
+}