Merge pull request 'feat: add cursor-based pagination to /jobs endpoint' (#59) from feature/cursor-pagination into main

SPARC/api.py

@@ -77,6 +77,13 @@ class JobStatus(BaseModel):
     error: str | None = None
 
 
+class PaginatedJobsResponse(BaseModel):
+    """Paginated response for job listings."""
+
+    items: list["JobStatus"]
+    next_cursor: str | None = None
+
+
 class HealthResponse(BaseModel):
     """Health check response."""
 
@@ -609,24 +616,51 @@ async def get_job_status(
     return _job_row_to_status(job_row)
 
 
-@app.get("/jobs", response_model=list[JobStatus], tags=["Jobs"])
+@app.get("/jobs", response_model=PaginatedJobsResponse, tags=["Jobs"])
 async def list_jobs(
     status: Annotated[
         str | None,
         Query(description="Filter by status: pending, running, completed, failed"),
     ] = None,
     limit: Annotated[int, Query(ge=1, le=100)] = 10,
+    cursor: Annotated[
+        str | None,
+        Query(description="Opaque cursor from a previous response's next_cursor field"),
+    ] = None,
     _: UserResponse = Depends(get_current_user),
 ):
-    """List all analysis jobs.
+    """List analysis jobs with cursor-based pagination.
+
+    Pass ``limit`` to control page size. The response includes a ``next_cursor``
+    field; pass it back as the ``cursor`` query parameter to fetch the next page.
+    When ``next_cursor`` is ``null``, there are no more results.
+
+    Existing clients that use only ``limit`` (without ``cursor``) continue to
+    work without modification.
 
     Args:
         status: Optional filter by job status
         limit: Maximum number of jobs to return (default 10, max 100)
+        cursor: Opaque pagination cursor from a previous response
 
     Returns:
-        List of job statuses
+        Paginated list of job statuses
     """
     db = _get_job_db()
-    job_rows = db.list_jobs(status=status, limit=limit)
-    return [_job_row_to_status(row) for row in job_rows]
+    # Fetch one extra to determine if there is a next page
+    job_rows = db.list_jobs(status=status, limit=limit + 1, cursor=cursor)
+
+    has_next = len(job_rows) > limit
+    if has_next:
+        job_rows = job_rows[:limit]
+
+    items = [_job_row_to_status(row) for row in job_rows]
+
+    next_cursor = None
+    if has_next and job_rows:
+        last = job_rows[-1]
+        created = last["created_at"]
+        ts = created.isoformat() if hasattr(created, "isoformat") else str(created)
+        next_cursor = f"{ts}|{last['job_id']}"
+
+    return PaginatedJobsResponse(items=items, next_cursor=next_cursor)

SPARC/database.py

@@ -568,20 +568,45 @@ class DatabaseClient:
         self,
         status: Optional[str] = None,
         limit: int = 10,
+        cursor: Optional[str] = None,
     ) -> List[Dict]:
-        """List jobs, optionally filtered by status."""
-        query = "SELECT * FROM jobs"
+        """List jobs with optional status filter and cursor-based pagination.
+
+        Args:
+            status: Optional status filter (pending, running, completed, failed).
+            limit: Maximum number of jobs to return.
+            cursor: Opaque cursor (``created_at|job_id``) from a previous
+                response. When provided, only jobs older than the cursor are
+                returned.
+
+        Returns:
+            List of job dicts ordered by created_at descending.
+        """
+        conditions: list[str] = []
         params: list = []
+
         if status:
-            query += " WHERE status = %s"
+            conditions.append("status = %s")
             params.append(status)
-        query += " ORDER BY created_at DESC LIMIT %s"
+
+        if cursor:
+            try:
+                ts_str, cursor_job_id = cursor.rsplit("|", 1)
+                conditions.append("(created_at, job_id) < (%s, %s)")
+                params.extend([ts_str, cursor_job_id])
+            except ValueError:
+                pass  # Ignore malformed cursors; return from start
+
+        query = "SELECT * FROM jobs"
+        if conditions:
+            query += " WHERE " + " AND ".join(conditions)
+        query += " ORDER BY created_at DESC, job_id DESC LIMIT %s"
         params.append(limit)
 
         with self.get_conn() as conn:
-            with conn.cursor(cursor_factory=RealDictCursor) as cursor:
-                cursor.execute(query, params)
-                return [dict(row) for row in cursor.fetchall()]
+            with conn.cursor(cursor_factory=RealDictCursor) as cur:
+                cur.execute(query, params)
+                return [dict(row) for row in cur.fetchall()]
 
     def mark_stale_jobs_failed(self) -> int:
         """Mark any jobs in 'running' or 'pending' state as 'failed'.