Kernelspec Caching

docs/source/api/jupyter_server.services.kernelspecs.monitors.rst

@@ -0,0 +1,25 @@
+jupyter\_server.services.kernelspecs.monitors package
+=====================================================
+
+Submodules
+----------
+
+
+.. automodule:: jupyter_server.services.kernelspecs.monitors.polling_monitor
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+
+.. automodule:: jupyter_server.services.kernelspecs.monitors.watchdog_monitor
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+Module contents
+---------------
+
+.. automodule:: jupyter_server.services.kernelspecs.monitors
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/source/api/jupyter_server.services.kernelspecs.rst

@@ -1,6 +1,14 @@
 jupyter\_server.services.kernelspecs package
 ============================================
 
+Subpackages
+-----------
+
+.. toctree::
+   :maxdepth: 4
+
+   jupyter_server.services.kernelspecs.monitors
+
 Submodules
 ----------
 
@@ -10,6 +18,12 @@ Submodules
    :undoc-members:
    :show-inheritance:
 
+
+.. automodule:: jupyter_server.services.kernelspecs.kernelspec_cache
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
 Module contents
 ---------------
 

jupyter_server/base/handlers.py

@@ -342,6 +342,10 @@ def terminal_manager(self):
     def kernel_spec_manager(self):
         return self.settings["kernel_spec_manager"]
 
+    @property
+    def kernel_spec_cache(self):
+        return self.settings["kernel_spec_cache"]
+
     @property
     def config_manager(self):
         return self.settings["config_manager"]

jupyter_server/kernelspecs/handlers.py

@@ -26,7 +26,7 @@ def initialize(self):
     @authorized
     async def get(self, kernel_name, path, include_body=True):
         """Get a kernelspec resource."""
-        ksm = self.kernel_spec_manager
+        ksc = self.kernel_spec_cache
         if path.lower().endswith(".png"):
             self.set_header("Cache-Control", f"max-age={60*60*24*30}")
         ksm = self.kernel_spec_manager
@@ -50,7 +50,7 @@ async def get(self, kernel_name, path, include_body=True):
                     )
                 )
         try:
-            kspec = await ensure_async(ksm.get_kernel_spec(kernel_name))
+            kspec = await ensure_async(ksc.get_kernel_spec(kernel_name))
             self.root = kspec.resource_dir
         except KeyError as e:
             raise web.HTTPError(404, "Kernel spec %s not found" % kernel_name) from e

jupyter_server/serverapp.py

@@ -108,6 +108,7 @@
     AsyncMappingKernelManager,
     MappingKernelManager,
 )
+from jupyter_server.services.kernelspecs.kernelspec_cache import KernelSpecCache
 from jupyter_server.services.sessions.sessionmanager import SessionManager
 from jupyter_server.utils import (
     check_pid,
@@ -235,6 +236,7 @@ def __init__(
         authorizer=None,
         identity_provider=None,
         kernel_websocket_connection_class=None,
+        kernel_spec_cache=None,
     ):
         """Initialize a server web application."""
         if identity_provider is None:
@@ -272,6 +274,7 @@ def __init__(
             authorizer=authorizer,
             identity_provider=identity_provider,
             kernel_websocket_connection_class=kernel_websocket_connection_class,
+            kernel_spec_cache=kernel_spec_cache,
         )
         handlers = self.init_handlers(default_services, settings)
 
@@ -296,6 +299,7 @@ def init_settings(
         authorizer=None,
         identity_provider=None,
         kernel_websocket_connection_class=None,
+        kernel_spec_cache=None,
     ):
         """Initialize settings for the web application."""
         _template_path = settings_overrides.get(
@@ -373,6 +377,7 @@ def init_settings(
             "contents_manager": contents_manager,
             "session_manager": session_manager,
             "kernel_spec_manager": kernel_spec_manager,
+            "kernel_spec_cache": kernel_spec_cache,
             "config_manager": config_manager,
             "authorizer": authorizer,
             "identity_provider": identity_provider,
@@ -1494,6 +1499,16 @@ def _default_session_manager_class(self):
             return "jupyter_server.gateway.managers.GatewaySessionManager"
         return SessionManager
 
+    kernel_spec_cache_class = Type(
+        default_value=KernelSpecCache,
+        klass=KernelSpecCache,
+        config=True,
+        help="""
+        The kernel spec cache class to use. Must be a subclass
+        of `jupyter_server.services.kernelspecs.kernelspec_cache.KernelSpecCache`.
+        """,
+    )
+
     kernel_websocket_connection_class = Type(
         klass=BaseKernelWebsocketConnection,
         config=True,
@@ -1892,6 +1907,11 @@ def init_configurables(self):
             kernel_manager=self.kernel_manager,
             contents_manager=self.contents_manager,
         )
+        self.kernel_spec_cache = self.kernel_spec_cache_class(
+            parent=self,
+            log=self.log,
+            kernel_spec_manager=self.kernel_spec_manager,
+        )
         self.config_manager = self.config_manager_class(
             parent=self,
             log=self.log,
@@ -2053,6 +2073,7 @@ def init_webapp(self):
             authorizer=self.authorizer,
             identity_provider=self.identity_provider,
             kernel_websocket_connection_class=self.kernel_websocket_connection_class,
+            kernel_spec_cache=self.kernel_spec_cache,
         )
         if self.certfile:
             self.ssl_options["certfile"] = self.certfile

jupyter_server/services/kernelspecs/handlers.py

@@ -62,12 +62,12 @@ class MainKernelSpecHandler(KernelSpecsAPIHandler):
     @authorized
     async def get(self):
         """Get the list of kernel specs."""
-        ksm = self.kernel_spec_manager
+        ksc = self.kernel_spec_cache
         km = self.kernel_manager
         model = {}
         model["default"] = km.default_kernel_name
         model["kernelspecs"] = specs = {}
-        kspecs = await ensure_async(ksm.get_all_specs())
+        kspecs = await ensure_async(ksc.get_all_specs())
         for kernel_name, kernel_info in kspecs.items():
             try:
                 if is_kernelspec_model(kernel_info):
@@ -94,10 +94,10 @@ class KernelSpecHandler(KernelSpecsAPIHandler):
     @authorized
     async def get(self, kernel_name):
         """Get a kernel spec model."""
-        ksm = self.kernel_spec_manager
+        ksc = self.kernel_spec_cache
         kernel_name = url_unescape(kernel_name)
         try:
-            spec = await ensure_async(ksm.get_kernel_spec(kernel_name))
+            spec = await ensure_async(ksc.get_kernel_spec(kernel_name))
         except KeyError as e:
             raise web.HTTPError(404, "Kernel spec %s not found" % kernel_name) from e
         if is_kernelspec_model(spec):