perf: batch tenant summary response assembly

src/govoplan_tenancy/backend/api/v1/routes.py

@@ -82,6 +82,7 @@ TENANT_NON_STATUS_UPDATE_FIELDS = {
     "allow_api_keys",
 }
 TENANT_GOVERNANCE_OVERRIDE_FIELDS = ("allow_custom_groups", "allow_custom_roles", "allow_api_keys")
+TENANT_FULL_CURSOR_PREFIX = "full:tenants:"
 
 
 def _tenant_access_provisioner() -> TenantAccessProvisioner:
@@ -141,7 +142,11 @@ def _tenant_item(session: Session, tenant: Tenant) -> TenantAdminItem:
             "allow_api_keys": governance.allow_api_keys,
         },
         is_active=tenant.is_active,
-        counts=tenant_counts(session, tenant.id),
+        counts=tenant_counts(
+            session,
+            tenant.id,
+            module_ids=("campaigns", "files"),
+        ),
         created_at=tenant.created_at,
         updated_at=tenant.updated_at,
     )
@@ -317,6 +322,50 @@ def _tenant_list_response_watermark(session: Session, *, entries, has_more: bool
     return encode_sequence_watermark(entries[-1].id) if has_more and entries else _tenant_list_watermark(session)
 
 
+def _tenant_page(query, *, page: int, page_size: int):
+    total = query.order_by(None).count()
+    pages = max(1, (total + page_size - 1) // page_size)
+    items = query.offset((page - 1) * page_size).limit(page_size).all()
+    return items, {
+        "total": total,
+        "page": page,
+        "page_size": page_size,
+        "pages": pages,
+    }
+
+
+def _tenant_full_cursor(
+    *,
+    page: int,
+    snapshot_sequence: int,
+) -> str:
+    return f"{TENANT_FULL_CURSOR_PREFIX}{int(page)}:{int(snapshot_sequence)}"
+
+
+def _decode_tenant_full_cursor(value: str | None) -> tuple[int, int] | None:
+    if not value or not value.startswith(TENANT_FULL_CURSOR_PREFIX):
+        return None
+    parts = value[len(TENANT_FULL_CURSOR_PREFIX):].split(":", 1)
+    if len(parts) != 2:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Invalid tenant full snapshot cursor",
+        )
+    try:
+        page, snapshot_sequence = (int(item) for item in parts)
+    except ValueError as exc:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Invalid tenant full snapshot cursor",
+        ) from exc
+    if page < 1 or snapshot_sequence < 0:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Invalid tenant full snapshot cursor",
+        )
+    return page, snapshot_sequence
+
+
 def _tenant_list_deleted_entries(entries: list[ChangeSequenceEntry], visible_tenant_ids: set[str]):
     return [
         {"id": entry.resource_id, "resource_type": entry.resource_type or TENANT_LIST_RESOURCE}
@@ -397,21 +446,54 @@ def switch_tenant_context(
 
 @router.get("/tenants", response_model=TenantListResponse)
 def list_tenants(
+    page: int = Query(default=1, ge=1),
+    page_size: int = Query(default=100, ge=1, le=500),
     session: Session = Depends(get_session),
     principal: ApiPrincipal = Depends(require_scope("system:tenants:read")),
 ):
-    tenants = session.query(Tenant).order_by(Tenant.name.asc()).all()
-    return TenantListResponse(tenants=[_tenant_item(session, tenant) for tenant in tenants])
+    tenants, pagination = _tenant_page(
+        session.query(Tenant).order_by(Tenant.name.asc(), Tenant.id.asc()),
+        page=page,
+        page_size=page_size,
+    )
+    return TenantListResponse(
+        tenants=[_tenant_item(session, tenant) for tenant in tenants],
+        **pagination,
+    )
 
 
-def _full_tenant_list_delta_response(session: Session) -> TenantListDeltaResponse:
-    tenants = session.query(Tenant).order_by(Tenant.name.asc()).all()
+def _full_tenant_list_delta_response(
+    session: Session,
+    *,
+    cursor: tuple[int, int] | None = None,
+    limit: int = 100,
+) -> TenantListDeltaResponse:
+    page = cursor[0] if cursor is not None else 1
+    snapshot_sequence = (
+        cursor[1]
+        if cursor is not None
+        else decode_sequence_watermark(_tenant_list_watermark(session))
+    )
+    tenants, pagination = _tenant_page(
+        session.query(Tenant).order_by(Tenant.name.asc(), Tenant.id.asc()),
+        page=page,
+        page_size=limit,
+    )
+    has_more = page < pagination["pages"]
     return TenantListDeltaResponse(
         tenants=[_tenant_item(session, tenant) for tenant in tenants],
         deleted=[],
-        watermark=_tenant_list_watermark(session),
-        has_more=False,
+        watermark=(
+            _tenant_full_cursor(
+                page=page + 1,
+                snapshot_sequence=snapshot_sequence,
+            )
+            if has_more
+            else encode_sequence_watermark(snapshot_sequence)
+        ),
+        has_more=has_more,
         full=True,
+        **pagination,
     )
 
 
@@ -423,11 +505,16 @@ def list_tenants_delta(
     principal: ApiPrincipal = Depends(require_scope("system:tenants:read")),
 ):
     del principal
-    if since is None:
-        return _full_tenant_list_delta_response(session)
+    full_cursor = _decode_tenant_full_cursor(since)
+    if since is None or full_cursor is not None:
+        return _full_tenant_list_delta_response(
+            session,
+            cursor=full_cursor,
+            limit=limit,
+        )
     entries, has_more = _tenant_list_delta_entries(session, since=since, limit=limit)
     if entries is None:
-        return _full_tenant_list_delta_response(session)
+        return _full_tenant_list_delta_response(session, limit=limit)
     changed_ids = [entry.resource_id for entry in entries if entry.resource_id and entry.operation != "deleted"]
     tenants = []
     if changed_ids:
@@ -439,6 +526,10 @@ def list_tenants_delta(
         watermark=_tenant_list_response_watermark(session, entries=entries, has_more=has_more),
         has_more=has_more,
         full=False,
+        total=len(tenants),
+        page=1,
+        page_size=limit,
+        pages=1,
     )
 
 

src/govoplan_tenancy/backend/api/v1/schemas.py

@@ -27,9 +27,13 @@ class TenantAdminItem(BaseModel):
 
 class TenantListResponse(BaseModel):
     tenants: list[TenantAdminItem]
+    total: int = 0
+    page: int = 1
+    page_size: int = 100
+    pages: int = 1
 
 
-class TenantListDeltaResponse(BaseModel):
+class TenantListDeltaResponse(TenantListResponse):
     tenants: list[TenantAdminItem] = Field(default_factory=list)
     deleted: list[DeltaDeletedItem] = Field(default_factory=list)
     watermark: str | None = None