aw-transform: Add union_events_split

Author: johan-bjareholt

aw-transform/src/lib.rs

@@ -44,3 +44,6 @@ pub use filter_period::filter_period_intersect;
 
 mod split_url;
 pub use split_url::split_url_event;
+
+mod union;
+pub use union::union_events_split;

aw-transform/src/union.rs

@@ -0,0 +1,178 @@
+use std::vec::Vec;
+
+use serde_json::{Map, Value};
+
+use aw_models::Event;
+
+fn merge_value(a: &mut Value, b: &Value) {
+    match (a, b) {
+        (&mut Value::Object(ref mut a), &Value::Object(ref b)) => {
+            for (kb, vb) in b {
+                merge_value(a.entry(kb.clone()).or_insert(Value::Null), vb);
+            }
+        }
+        (a, b) => {
+            *a = b.clone();
+        }
+    }
+}
+
+fn merge_map(map1: &mut Map<String, Value>, map2: &Map<String, Value>) {
+    for (k1, mut v1) in map1.iter_mut() {
+        if let Some(v2) = map2.get(k1) {
+            merge_value(&mut v1, &v2);
+            println!("{:?}", v1);
+        }
+    }
+    for (k2, v2) in map2.iter() {
+        if !map1.contains_key(k2) {
+            map1.insert(k2.to_string(), v2.clone());
+        }
+    }
+}
+
+/// events1 is the "master" list of events and if an event in events2
+/// intersects it the intersecting part will be removed from the original
+/// event and split into a new event and merges the data. It also differs from
+/// a normal intersection in that the part that does not intersect from the
+/// "master" events will still be kept, but if it also intersects that interval
+/// will be removed.
+///
+/// NOTE: It is technically only a union of the event1, not event2.
+///       Maybe we should improve that in the future?
+///
+/// Example:
+/// ```ignore
+///     |---------|--------------------|
+///     | events1 |[a     ][b     ]    |
+///     | events2 |    [c     ]    [d ]|
+///     | result  |[a ][ac][bc][b ]    |
+///     |---------|--------------------|
+/// ```
+pub fn union_events_split(events1: Vec<Event>, events2: &Vec<Event>) -> Vec<Event> {
+    let mut events: Vec<Event> = Vec::new();
+
+    'event1: for mut event1 in events1 {
+        let event1_endtime = event1.calculate_endtime();
+        'event2: for event2 in events2 {
+            // Check that events intersect, otherwise skip
+            if event2.timestamp > event1_endtime {
+                continue 'event2;
+            }
+            let event2_endtime = event2.calculate_endtime();
+            if event2_endtime < event1.timestamp {
+                continue 'event2;
+            }
+            // Find the events common intersection
+            let intersect_timestamp = std::cmp::max(event1.timestamp, event2.timestamp);
+            let intersect_endtime = std::cmp::min(event1_endtime, event2_endtime);
+            let intersect_duration = intersect_endtime - intersect_timestamp;
+
+            // If event1 starts before event2, add that event
+            if intersect_timestamp > event1.timestamp {
+                let prepended_event = Event {
+                    id: None,
+                    timestamp: event1.timestamp,
+                    duration: intersect_timestamp - event1.timestamp,
+                    data: event1.data.clone(),
+                };
+                events.push(prepended_event);
+            }
+
+            // Add intersecting event
+            let mut intersect_data = event1.data.clone();
+            merge_map(&mut intersect_data, &event2.data);
+            let intersecting_event = Event {
+                id: None,
+                timestamp: intersect_timestamp,
+                duration: intersect_duration,
+                data: intersect_data,
+            };
+            events.push(intersecting_event);
+
+            // Update event1 to end at end of common event
+            event1.timestamp = intersect_endtime;
+            event1.duration = event1_endtime - intersect_endtime;
+            if event1.duration.num_milliseconds() <= 0 {
+                continue 'event1;
+            }
+        }
+        events.push(event1);
+    }
+
+    events
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use chrono::DateTime;
+    use chrono::Duration;
+    use serde_json::json;
+    use std::str::FromStr;
+
+    #[test]
+    fn test_merge_data() {
+        /* test merge same */
+        let mut d1 = json_map! {"test": json!(1)};
+        let d2 = d1.clone();
+        merge_map(&mut d1, &d2);
+        assert_eq!(d1, d2);
+
+        /* test merge different keys */
+        let mut d1 = json_map! {"test1": json!(1)};
+        let d2 = json_map! {"test2": json!(2)};
+        merge_map(&mut d1, &d2);
+        assert_eq!(d1, json_map! {"test1": json!(1), "test2": json!(2)});
+
+        /* test merge intersecting objects */
+        let mut d1 = json_map! {"test": json_map!{"a": json!(1)}};
+        let d2 = json_map! {"test": json_map!{"b": json!(2)}};
+        merge_map(&mut d1, &d2);
+        assert_eq!(
+            d1,
+            json_map! {"test": json_map!{"a": json!(1), "b": json!(2)}}
+        );
+
+        /* test non-object conflict, prefer map1 value */
+        // TODO: This does not work yet!
+        //       It should be a pretty rare use-case anyway
+        /*
+        let mut d1 = json_map!{"test": json!(1)};
+        let d1_orig = d1.clone();
+        let d2 = json_map!{"test": json!(2)};
+        merge_map(&mut d1, &d2);
+        assert_eq!(d1, d1_orig);
+        */
+    }
+
+    #[test]
+    fn test_union_events_split() {
+        // Test intersection, before and after
+        let e1 = Event {
+            id: None,
+            timestamp: DateTime::from_str("2000-01-01T00:00:00Z").unwrap(),
+            duration: Duration::seconds(3),
+            data: json_map! {"test": json!(1)},
+        };
+        let mut e2 = e1.clone();
+        e2.timestamp = DateTime::from_str("2000-01-01T00:00:01Z").unwrap();
+        e2.duration = Duration::seconds(1);
+
+        let res = union_events_split(vec![e1.clone()], &vec![e2.clone()]);
+        assert_eq!(res.len(), 3);
+        assert_eq!(res[0].id, None);
+        assert_eq!(res[0].timestamp, e1.timestamp);
+        assert_eq!(res[0].duration, Duration::seconds(1));
+        assert_eq!(res[0].data, json_map! {"test": json!(1)});
+        assert_eq!(res[1].id, None);
+        assert_eq!(res[1].timestamp, e2.timestamp);
+        assert_eq!(res[1].duration, Duration::seconds(1));
+        assert_eq!(res[1].data, json_map! {"test": json!(1)});
+        assert_eq!(res[2].id, None);
+        assert_eq!(res[2].timestamp, e2.timestamp + e2.duration);
+        assert_eq!(res[2].duration, Duration::seconds(1));
+        assert_eq!(res[2].data, json_map! {"test": json!(1)});
+    }
+}