Add HTML reprs to some scheduler classes (#4795)

Author: jrbourbeau

distributed/scheduler.py

@@ -1,4 +1,5 @@
 import asyncio
+import html
 import inspect
 import itertools
 import json
@@ -732,13 +733,22 @@ def clean(self):
         return ws
 
     def __repr__(self):
-        return "<Worker %r, name: %s, memory: %d, processing: %d>" % (
+        return "<WorkerState %r, name: %s, memory: %d, processing: %d>" % (
             self._address,
             self._name,
             len(self._has_what),
             len(self._processing),
         )
 
+    def _repr_html_(self):
+        text = (
+            f"<b>WorkerState: </b> {html.escape(self._address)} "
+            f'<font style="color: var(--jp-ui-font-color2, gray)">name: </font>{self.name} '
+            f'<font style="color: var(--jp-ui-font-color2, gray)">memory: </font>{len(self._has_what)} '
+            f'<font style="color: var(--jp-ui-font-color2, gray)">processing: </font>{len(self._processing)}'
+        )
+        return text
+
     @ccall
     @exceptval(check=False)
     def identity(self) -> dict:
@@ -1549,7 +1559,19 @@ def set_nbytes(self, nbytes: Py_ssize_t):
         self._nbytes = nbytes
 
     def __repr__(self):
-        return "<Task %r %s>" % (self._key, self._state)
+        return "<TaskState %r %s>" % (self._key, self._state)
+
+    def _repr_html_(self):
+        color = (
+            "var(--jp-error-color0, red)"
+            if self._state == "erred"
+            else "var(--jp-ui-font-color0, black)"
+        )
+        text = f'<b>TaskState: </b> <font style="color: {color}">{self._state} </font>'
+        if self._state == "memory":
+            text += f'<font style="color: var(--jp-ui-font-color2, gray)">nbytes: </font>{format_bytes(self._nbytes)} '
+        text += f'<font style="color: var(--jp-ui-font-color2, gray)">key: </font>{html.escape(self._key)}'
+        return text
 
     @ccall
     def validate(self):
@@ -3579,11 +3601,22 @@ def __init__(
 
     def __repr__(self):
         parent: SchedulerState = cast(SchedulerState, self)
-        return '<Scheduler: "%s" processes: %d cores: %d>' % (
+        return '<Scheduler: "%s" workers: %d cores: %d, tasks: %d>' % (
             self.address,
             len(parent._workers),
             parent._total_nthreads,
+            len(parent._tasks),
+        )
+
+    def _repr_html_(self):
+        parent: SchedulerState = cast(SchedulerState, self)
+        text = (
+            f"<b>Scheduler: </b>{html.escape(self.address)} "
+            f'<font color="gray">workers: </font>{len(parent._workers)} '
+            f'<font color="gray">cores: </font>{parent._total_nthreads} '
+            f'<font color="gray">tasks: </font>{len(parent._tasks)}'
         )
+        return text
 
     def identity(self, comm=None):
         """ Basic information about ourselves and our cluster """