nexus_common/models/follow/
traits.rs

1use crate::db::{execute_graph_operation, get_neo4j_graph, queries, OperationOutcome, RedisOps};
2use crate::types::DynError;
3use async_trait::async_trait;
4use chrono::Utc;
5use neo4rs::Query;
6
7#[async_trait]
8pub trait UserFollows: Sized + RedisOps + AsRef<[String]> + Default {
9    fn from_vec(vec: Vec<String>) -> Self;
10
11    async fn put_to_graph(
12        follower_id: &str,
13        followee_id: &str,
14    ) -> Result<OperationOutcome, DynError> {
15        let indexed_at = Utc::now().timestamp_millis();
16        let query = queries::put::create_follow(follower_id, followee_id, indexed_at);
17        execute_graph_operation(query).await
18    }
19
20    async fn get_by_id(
21        user_id: &str,
22        skip: Option<usize>,
23        limit: Option<usize>,
24    ) -> Result<Option<Self>, DynError> {
25        match Self::get_from_index(user_id, skip, limit).await? {
26            Some(connections) => Ok(Some(Self::from_vec(connections))),
27            None => {
28                let graph_response = Self::get_from_graph(user_id, skip, limit).await?;
29                if let Some(follows) = graph_response {
30                    follows.put_to_index(user_id).await?;
31                    return Ok(Some(follows));
32                }
33                Ok(None)
34            }
35        }
36    }
37
38    async fn get_from_graph(
39        user_id: &str,
40        skip: Option<usize>,
41        limit: Option<usize>,
42    ) -> Result<Option<Self>, DynError> {
43        let mut result;
44        {
45            let graph = get_neo4j_graph()?;
46            let query = Self::get_query(user_id, skip, limit);
47
48            let graph = graph.lock().await;
49            result = graph.execute(query).await?;
50        }
51
52        if let Some(row) = result.next().await? {
53            let user_exists: bool = row.get("user_exists").unwrap_or(false);
54            if !user_exists {
55                return Ok(None);
56            }
57
58            match row.get::<Option<Vec<String>>>(Self::get_ids_field_name()) {
59                Ok(response) => {
60                    if let Some(connections) = response {
61                        return Ok(Some(Self::from_vec(connections)));
62                    } else {
63                        return Ok(Some(Self::default()));
64                    }
65                }
66                Err(_e) => return Ok(None),
67            }
68        } else {
69            Ok(None)
70        }
71    }
72
73    async fn get_from_index(
74        user_id: &str,
75        skip: Option<usize>,
76        limit: Option<usize>,
77    ) -> Result<Option<Vec<String>>, DynError> {
78        Self::try_from_index_set(&[user_id], skip, limit, None).await
79    }
80
81    async fn put_to_index(&self, user_id: &str) -> Result<(), DynError> {
82        let user_list_ref: Vec<&str> = self.as_ref().iter().map(|id| id.as_str()).collect();
83        Self::put_index_set(&[user_id], &user_list_ref, None, None).await
84    }
85
86    async fn reindex(user_id: &str) -> Result<(), DynError> {
87        match Self::get_from_graph(user_id, None, None).await? {
88            Some(follow) => follow.put_to_index(user_id).await?,
89            None => tracing::error!(
90                "{}: Could not found user follow relationship in the graph",
91                user_id
92            ),
93        }
94        Ok(())
95    }
96
97    async fn del_from_graph(
98        follower_id: &str,
99        followee_id: &str,
100    ) -> Result<OperationOutcome, DynError> {
101        let query = queries::del::delete_follow(follower_id, followee_id);
102        execute_graph_operation(query).await
103    }
104
105    async fn del_from_index(&self, user_id: &str) -> Result<(), DynError> {
106        self.remove_from_index_set(&[user_id]).await
107    }
108
109    fn get_query(user_id: &str, skip: Option<usize>, limit: Option<usize>) -> Query;
110
111    fn get_ids_field_name() -> &'static str;
112
113    // Checks whether user_a is (following | follower) of user_b
114    async fn check(user_a_id: &str, user_b_id: &str) -> Result<bool, DynError> {
115        let user_a_key_parts = &[user_a_id][..];
116        let (_, follow) = Self::check_set_member(user_a_key_parts, user_b_id).await?;
117        Ok(follow)
118    }
119}
nexus_common/models/follow/traits.rs

nexus_common/models/follow/
traits.rs
