added option the create several channels at once

bstrd/bscache.py

@@ -45,6 +45,38 @@ class BSCache:
         self.pt.stop()
 
 
+    def get_vars(self, names):
+        if not isinstance(names, dict):
+            names = {n: {} for n in names}
+
+        new_chans = {}
+        for name, kwargs in names.items():
+            if name not in ["pid", "toc"] and name not in self.channels:
+                if not is_available(name):
+                    raise ValueError(f"channel {name} is not available")
+                cfg = make_channel_config(name, *kwargs)
+                new_chans[name] = cfg
+
+        self.update_source_multiple(new_chans)
+        return {n: BSVar(n, self) for n in names}
+
+
+    def update_source_multiple(self, chans):
+        self.pt.stop()
+        print("add channels", sorted(chans))
+        self.channels.update(chans)
+        self.pt.start()
+
+        while self.data is None:
+            print("dropping empty data")
+            next(self)
+
+        while not chans.keys() <= self.data.keys():
+            missing = self.data.keys() - chans.keys() - {"pid", "toc"}
+            print("dropping data that is missing new channel(s)", sorted(missing))
+            next(self)
+
+
     def get_var(self, name, modulo=None, offset=None):
         if name not in ["pid", "toc"] and name not in self.channels:
             if not is_available(name):
@@ -80,7 +112,7 @@ def get_available_channels():
 
 
 
-def make_channel_config(name, modulo, offset):
+def make_channel_config(name, modulo=None, offset=None):
     res = {}
     if modulo is not None:
         res["modulo"] = modulo