Merge pull request #716 from tmillr/fix-launchd-calendar-interval

fix(launchd): improve `StartCalendarInterval`

modules/launchd/launchd.nix

@@ -2,6 +2,10 @@
 
 with lib;
 
+let
+  launchdTypes = import ./types.nix { inherit config lib; };
+in
+
 {
   options = {
     Label = mkOption {
@@ -344,55 +348,21 @@ with lib;
       default = null;
       example = [{ Hour = 2; Minute = 30; }];
       description = ''
-        This optional key causes the job to be started every calendar interval as specified. Missing arguments
+        This optional key causes the job to be started every calendar interval as specified. The semantics are
-        are considered to be wildcard. The semantics are much like `crontab(5)`.  Unlike cron which skips job
+        much like {manpage}`crontab(5)`: Missing attributes are considered to be wildcard. Unlike cron which skips
-        invocations when the computer is asleep, launchd will start the job the next time the computer wakes
+        job invocations when the computer is asleep, launchd will start the job the next time the computer wakes
         up.  If multiple intervals transpire before the computer is woken, those events will be coalesced into
-        one event upon wake from sleep.
+        one event upon waking from sleep.
+
+        ::: {.important}
+        The list must not be empty and must not contain duplicate entries (attrsets which compare equally).
+        :::
+
+        ::: {.caution}
+        Since missing attrs become wildcards, an empty attrset effectively means "every minute".
+        :::
       '';
-      type = types.nullOr (types.listOf (types.submodule {
+      type = types.nullOr launchdTypes.StartCalendarInterval;
-        options = {
-          Minute = mkOption {
-            type = types.nullOr types.int;
-            default = null;
-            description = ''
-              The minute on which this job will be run.
-            '';
-          };
-
-          Hour = mkOption {
-            type = types.nullOr types.int;
-            default = null;
-            description = ''
-              The hour on which this job will be run.
-            '';
-          };
-
-          Day = mkOption {
-            type = types.nullOr types.int;
-            default = null;
-            description = ''
-              The day on which this job will be run.
-            '';
-          };
-
-          Weekday = mkOption {
-            type = types.nullOr types.int;
-            default = null;
-            description = ''
-              The weekday on which this job will be run (0 and 7 are Sunday).
-            '';
-          };
-
-          Month = mkOption {
-            type = types.nullOr types.int;
-            default = null;
-            description = ''
-              The month on which this job will be run.
-            '';
-          };
-        };
-      }));
     };
 
     StandardInPath = mkOption {
@@ -895,6 +865,5 @@ with lib;
     };
   };
 
-  config = {
+  config = {};
-  };
 }

modules/launchd/types.nix

@@ -0,0 +1,110 @@
+{ lib, ... }:
+
+let
+  inherit (lib) imap1 types mkOption showOption optionDescriptionPhrase mergeDefinitions;
+  inherit (builtins) map filter length deepSeq throw toString concatLists;
+  inherit (lib.options) showDefs;
+  wildcardText = lib.literalMD "`*`";
+
+  /**
+    A type of list which does not allow duplicate elements. The base/inner
+    list type to use (e.g. `types.listOf` or `types.nonEmptyListOf`) is passed
+    via argument `listType`, which must be the final type and not a function.
+
+    NOTE: The extra check for duplicates is quadratic and strict, so use this
+    type sparingly and only:
+
+      * when needed, and
+      * when the list is expected to be recursively short (e.g. < 10 elements)
+        and shallow (i.e. strict evaluation of the list won't take too long)
+
+    The implementation of this function is similar to that of
+    `types.nonEmptyListOf`.
+  */
+  types'.uniqueList = listType: listType // {
+      description = "unique ${types.optionDescriptionPhrase (class: class == "noun") listType}";
+      substSubModules = m: types'.uniqueList (listType.substSubModules m);
+      # This has been taken from the implementation of `types.listOf`, but has
+      # been modified to throw on duplicates. This check cannot be done in the
+      # `check` fn as this check is deep/strict, and because `check` runs
+      # prior to merging.
+      merge = loc: defs:
+        let
+          # Each element of `dupes` is a list. When there are duplicates,
+          # later lists will be duplicates of earlier lists, so just throw on
+          # the first set of duplicates found so that we don't have duplicate
+          # error msgs.
+          checked = filter (li:
+            if length li > 1
+            then throw "The option `${showOption loc}' contains duplicate entries after merging:\n${showDefs li}"
+            else false) dupes;
+          dupes = map (def: filter (def': def'.value == def.value) merged) merged;
+          merged = filter (x: x ? value) (concatLists (imap1 (n: def:
+            imap1 (m: el:
+              let
+                inherit (def) file;
+                loc' = loc ++ ["[definition ${toString n}-entry ${toString m}]"];
+              in
+                (mergeDefinitions
+                  loc'
+                  listType.nestedTypes.elemType
+                  [{ inherit file; value = el; }]
+                ).optionalValue // {inherit loc' file;}
+            ) def.value
+          ) defs));
+      in
+        deepSeq checked (map (x: x.value) merged);
+    };
+in {
+  StartCalendarInterval = let
+    CalendarIntervalEntry = types.submodule {
+      options = {
+        Minute = mkOption {
+          type = types.nullOr (types.ints.between 0 59);
+          default = null;
+          defaultText = wildcardText;
+          description = ''
+            The minute on which this job will be run.
+          '';
+        };
+
+        Hour = mkOption {
+          type = types.nullOr (types.ints.between 0 23);
+          default = null;
+          defaultText = wildcardText;
+          description = ''
+            The hour on which this job will be run.
+          '';
+        };
+
+        Day = mkOption {
+          type = types.nullOr (types.ints.between 1 31);
+          default = null;
+          defaultText = wildcardText;
+          description = ''
+            The day on which this job will be run.
+          '';
+        };
+
+        Weekday = mkOption {
+          type = types.nullOr (types.ints.between 0 7);
+          default = null;
+          defaultText = wildcardText;
+          description = ''
+            The weekday on which this job will be run (0 and 7 are Sunday).
+          '';
+        };
+
+        Month = mkOption {
+          type = types.nullOr (types.ints.between 1 12);
+          default = null;
+          defaultText = wildcardText;
+          description = ''
+            The month on which this job will be run.
+          '';
+        };
+      };
+    };
+  in
+    types.either CalendarIntervalEntry (types'.uniqueList (types.nonEmptyListOf CalendarIntervalEntry));
+}

modules/services/nix-gc/default.nix

@@ -6,6 +6,7 @@ with lib;
 
 let
   cfg = config.nix.gc;
+  launchdTypes = import ../../launchd/types.nix { inherit config lib; };
 in
 
 {
@@ -35,9 +36,13 @@ in
       };
 
       interval = mkOption {
-        type = types.attrs;
+        type = launchdTypes.StartCalendarInterval;
-        default = { Hour = 3; Minute = 15; };
+        default = [{ Weekday = 7; Hour = 3; Minute = 15; }];
-        description = "The time interval at which the garbage collector will run.";
+        description = ''
+          The calendar interval at which the garbage collector will run.
+          See the {option}`serviceConfig.StartCalendarInterval` option of
+          the {option}`launchd` module for more info.
+        '';
       };
 
       options = mkOption {
@@ -63,7 +68,7 @@ in
       command = "${config.nix.package}/bin/nix-collect-garbage ${cfg.options}";
       environment.NIX_REMOTE = optionalString config.nix.useDaemon "daemon";
       serviceConfig.RunAtLoad = false;
-      serviceConfig.StartCalendarInterval = [ cfg.interval ];
+      serviceConfig.StartCalendarInterval = cfg.interval;
       serviceConfig.UserName = cfg.user;
     };
 

modules/services/nix-optimise/default.nix

@@ -14,6 +14,7 @@ let
     ;
 
   cfg = config.nix.optimise;
+  launchdTypes = import ../../launchd/types.nix { inherit config lib; };
 in
 
 {
@@ -41,9 +42,13 @@ in
       };
 
       interval = mkOption {
-        type = types.attrs;
+        type = launchdTypes.StartCalendarInterval;
-        default = { Hour = 3; Minute = 15; };
+        default = [{ Weekday = 7; Hour = 4; Minute = 15; }];
-        description = "The time interval at which the optimiser will run.";
+        description = ''
+          The calendar interval at which the optimiser will run.
+          See the {option}`serviceConfig.StartCalendarInterval` option of
+          the {option}`launchd` module for more info.
+        '';
       };
 
     };
@@ -63,7 +68,7 @@ in
           "/bin/wait4path ${config.nix.package} && exec ${config.nix.package}/bin/nix-store --optimise"
         ];
         RunAtLoad = false;
-        StartCalendarInterval = [ cfg.interval ];
+        StartCalendarInterval = cfg.interval;
         UserName = cfg.user;
       };
     };