revng daemon: add save mutation

Add the `save` mutation to the GraphQL api. This allows a client to
trigger saving.

python/revng/internal/api/manager.py

@@ -52,7 +52,7 @@ class Manager:
     def uid(self) -> int:
         return int(ffi.cast("uintptr_t", self._manager))
 
-    def save(self):
+    def save(self) -> bool:
         return _api.rp_manager_save(self._manager)
 
     # description utilities

python/revng/internal/daemon/event_manager.py

@@ -6,7 +6,7 @@ import time
 from enum import StrEnum, auto
 from functools import wraps
 from threading import Thread
-from typing import Callable, Iterable
+from typing import Callable, Iterable, cast
 
 from revng.internal.api import Manager
 
@@ -60,12 +60,12 @@ class EventManager(Thread):
                 self.last_save = time.time()
             time.sleep(10)
 
-    def save(self):
+    def save(self) -> bool:
         result = self.manager.save()
         if result:
             self.next_save = None
             for hook in self.save_hooks:
-                hook(self.manager, self.credentials)
+                hook(self.manager, cast(str, self.credentials))
         return result
 
     def handle_event(self, type_: EventType):

python/revng/internal/daemon/graphql.py

@@ -21,7 +21,7 @@ from revng.internal.api.errors import DocumentError, Error, SimpleError
 from revng.internal.api.manager import Manager
 from revng.internal.api.target import Target
 
-from .event_manager import EventType, emit_event
+from .event_manager import EventManager, EventType, emit_event
 from .multiqueue import MultiQueue
 from .util import produce_serializer
 
@@ -171,6 +171,12 @@ async def resolve_context_commit_index(_, info) -> int:
     return await run_in_executor(manager.get_context_commit_index)
 
 
+@mutation.field("save")
+async def resolve_save(_, info) -> bool:
+    event_manager: EventManager = info.context["event_manager"]
+    return await run_in_executor(event_manager.save)
+
+
 @mutation.field("uploadB64")
 @emit_event(EventType.BEGIN)
 async def resolve_upload_b64(_, info, *, input: str, container: str):  # noqa: A002

python/revng/internal/daemon/schema.graphql

@@ -28,6 +28,7 @@ type Target {
 }
 
 type Mutation {
+    save: Boolean!
     uploadB64(input: String!, container: String!): Boolean!
     uploadFile(file: Upload, container: String!): Boolean!
     runAnalysis(step: String!, analysis: String!, containerToTargets: String, options: String, index: BigInt!): AnalysisResult!