Add new package with methods to save and load compressor state (#63)

compressor_integration_tests/tests/auto_compressor_state_saving_tests.rs

@@ -0,0 +1,28 @@
+use auto_compressor::state_saving::{
+    connect_to_database, create_tables_if_needed, read_room_compressor_state,
+    write_room_compressor_state,
+};
+use compressor_integration_tests::{clear_compressor_state, DB_URL};
+use serial_test::serial;
+use synapse_compress_state::Level;
+
+#[test]
+#[serial(db)]
+fn write_then_read_state_gives_correct_results() {
+    let mut client = connect_to_database(DB_URL).unwrap();
+    create_tables_if_needed(&mut client).unwrap();
+    clear_compressor_state();
+
+    let room_id = "room1";
+    let written_info: Vec<Level> =
+        vec![Level::restore(3, 1, Some(6)), Level::restore(3, 2, Some(6))];
+    let written_num = 53;
+    write_room_compressor_state(&mut client, room_id, &written_info, written_num).unwrap();
+
+    let (read_num, read_info) = read_room_compressor_state(&mut client, room_id)
+        .unwrap()
+        .unwrap();
+
+    assert_eq!(written_info, read_info);
+    assert_eq!(written_num, read_num);
+}