Do not load PR from database unnecessarily when updating its mergeability state

Author: Kobzol

.sqlx/query-0f0acf10f909aa60beaedde032c1770566948a06c2b2e1f07806e948d83803e1.json

@@ -230,7 +230,7 @@ async fn handle_start_auto_build(
             tracing::debug!("Failed to start auto build for PR {pr_num} due to merge conflict");
 
             ctx.db
-                .update_pr_mergeable_state(pr, MergeableState::Unknown)
+                .set_pr_mergeable_state(repo.repository(), pr.number, MergeableState::Unknown)
                 .await?;
             repo.client
                 .post_comment(pr.number, merge_conflict_comment(&gh_pr.head.name))

.sqlx/query-3cc3661fb1e1ff945e415f80637e7d7614ffac5358b73ff039220ffed15c4fce.json

@@ -297,19 +297,12 @@ pub async fn check_mergeability(
     }
 
     // We know the mergeability status, so update it in the DB
-    let pr_model = match ctx
-        .db
-        .get_pull_request(&pull_request.repo, pull_request.pr_number)
-        .await?
-    {
-        Some(model) => model,
-        None => {
-            return Err(anyhow::anyhow!("PR not found in database: {pull_request}"));
-        }
-    };
-
     ctx.db
-        .update_pr_mergeable_state(&pr_model, new_mergeable_state.clone().into())
+        .set_pr_mergeable_state(
+            repo_state.repository(),
+            fetched_pr.number,
+            new_mergeable_state.into(),
+        )
         .await?;
 
     Ok(())

src/bors/merge_queue.rs

@@ -16,9 +16,9 @@ use super::operations::{
     get_nonclosed_pull_requests, get_pending_builds, get_prs_with_unknown_mergeability_state,
     get_pull_request, get_repository, get_repository_by_name, get_tagged_bot_comments,
     get_workflow_urls_for_build, get_workflows_for_build, insert_repo_if_not_exists,
-    record_tagged_bot_comment, set_pr_assignees, set_pr_priority, set_pr_rollup, set_pr_status,
-    unapprove_pull_request, undelegate_pull_request, update_build_check_run_id,
-    update_build_status, update_mergeable_states_by_base_branch, update_pr_mergeability_state,
+    record_tagged_bot_comment, set_pr_assignees, set_pr_mergeability_state, set_pr_priority,
+    set_pr_rollup, set_pr_status, unapprove_pull_request, undelegate_pull_request,
+    update_build_check_run_id, update_build_status, update_mergeable_states_by_base_branch,
     update_pr_try_build_id, update_workflow_status, upsert_pull_request, upsert_repository,
 };
 use super::{ApprovalInfo, DelegatedPermission, MergeableState, RunId, UpsertPullRequestParams};
@@ -69,12 +69,13 @@ impl PgDbClient {
         undelegate_pull_request(&self.pool, pr.id).await
     }
 
-    pub async fn update_pr_mergeable_state(
+    pub async fn set_pr_mergeable_state(
         &self,
-        pr: &PullRequestModel,
+        repo: &GithubRepoName,
+        pr_number: PullRequestNumber,
         mergeable_state: MergeableState,
     ) -> anyhow::Result<()> {
-        update_pr_mergeability_state(&self.pool, pr.id, mergeable_state).await
+        set_pr_mergeability_state(&self.pool, repo, pr_number, mergeable_state).await
     }
 
     pub async fn set_pr_assignees(

src/bors/mergeability_queue.rs

@@ -235,16 +235,18 @@ pub(crate) async fn get_nonclosed_pull_requests(
     .await
 }
 
-pub(crate) async fn update_pr_mergeability_state(
+pub(crate) async fn set_pr_mergeability_state(
     executor: impl PgExecutor<'_>,
-    pr_id: i32,
+    repo: &GithubRepoName,
+    pr_number: PullRequestNumber,
     mergeability_state: MergeableState,
 ) -> anyhow::Result<()> {
     measure_db_query("update_pr_mergeability_state", || async {
         sqlx::query!(
-            "UPDATE pull_request SET mergeable_state = $1 WHERE id = $2",
+            "UPDATE pull_request SET mergeable_state = $3 WHERE repository = $1 AND number = $2",
+            repo as &GithubRepoName,
+            pr_number.0 as i32,
             mergeability_state as _,
-            pr_id
         )
         .execute(executor)
         .await?;