fc-common: add failed paths cache infrastructure

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I35f9bfb044160151cf73c43ed9ada3476a6a6964

crates/common/src/repo/failed_paths_cache.rs

@@ -0,0 +1,64 @@
+use sqlx::PgPool;
+use uuid::Uuid;
+
+use crate::{
+  error::{CiError, Result},
+  models::BuildStatus,
+};
+
+pub async fn is_cached_failure(pool: &PgPool, drv_path: &str) -> Result<bool> {
+  let row: Option<(bool,)> =
+    sqlx::query_as("SELECT true FROM failed_paths_cache WHERE drv_path = $1")
+      .bind(drv_path)
+      .fetch_optional(pool)
+      .await
+      .map_err(CiError::Database)?;
+
+  Ok(row.is_some())
+}
+
+pub async fn insert(
+  pool: &PgPool,
+  drv_path: &str,
+  failure_status: BuildStatus,
+  source_build_id: Uuid,
+) -> Result<()> {
+  let status_str = failure_status.to_string();
+  sqlx::query(
+    "INSERT INTO failed_paths_cache (drv_path, source_build_id, \
+     failure_status, failed_at) VALUES ($1, $2, $3, NOW()) ON CONFLICT \
+     (drv_path) DO UPDATE SET source_build_id = $2, failure_status = $3, \
+     failed_at = NOW()",
+  )
+  .bind(drv_path)
+  .bind(source_build_id)
+  .bind(&status_str)
+  .execute(pool)
+  .await
+  .map_err(CiError::Database)?;
+
+  Ok(())
+}
+
+pub async fn invalidate(pool: &PgPool, drv_path: &str) -> Result<()> {
+  sqlx::query("DELETE FROM failed_paths_cache WHERE drv_path = $1")
+    .bind(drv_path)
+    .execute(pool)
+    .await
+    .map_err(CiError::Database)?;
+
+  Ok(())
+}
+
+pub async fn cleanup_expired(pool: &PgPool, ttl_seconds: u64) -> Result<u64> {
+  let result = sqlx::query(
+    "DELETE FROM failed_paths_cache WHERE failed_at < NOW() - \
+     make_interval(secs => $1)",
+  )
+  .bind(ttl_seconds as f64)
+  .execute(pool)
+  .await
+  .map_err(CiError::Database)?;
+
+  Ok(result.rows_affected())
+}