WiP! RRD support

README.md

@@ -28,6 +28,23 @@ Example configuration:
     $cap <cache { dataspace: $nixspace lifetime: 3600.0 }> ]
 ]
 ```
+### File System Usage
+
+Summarize the size of file-system directory. Equivalent to `du -s -b`.
+Query the size of a directory in bytes by observing `<file-system-usage "/SOME/PATH" ?size>`.
+
+```
+# Configuration example
+
+? <exposed-dataspace ?ds> [
+
+  <require-service <daemon syndesizer>>
+  ? <service-object <daemon syndesizer> ?cap> [
+    $cap <file-system-usage { dataspace: $ds }>
+  ]
+
+]
+```
 
 ### JSON Socket Translator
 

assertions.prs

@@ -0,0 +1,3 @@
+version 1.
+
+FileSystemUsage = <file-system-usage @path string @size int>.

config.prs

@@ -6,6 +6,10 @@ CacheArguments = <cache {
   lifetime: float
 }>.
 
+FileSystemUsageArguments = <file-system-usage {
+  dataspace: #!any
+}>.
+
 JsonTranslatorArguments = <json-stdio-translator {
   argv: [string ...]
   dataspace: #!any
@@ -18,6 +22,8 @@ JsonSocketTranslatorArguments = <json-socket-translator {
   socket: string
 }>.
 
+RrdArguments = <rrd { dataspace: #!any }>.
+
 SqliteArguments = <sqlite {
   database: string
   dataspace: #!any

rrd.prs

@@ -0,0 +1,3 @@
+version 1.
+
+RRDaction = <rrd @verb symbol @args [string...]>.

shell.nix

@@ -3,5 +3,5 @@
 pkgs.buildNimPackage {
   name = "dummy";
   propagatedNativeBuildInputs = [ pkgs.pkg-config ];
-  propagatedBuildInputs = [ pkgs.sqlite ];
+  propagatedBuildInputs = [ pkgs.rrdtool pkgs.sqlite ];
 }

src/schema/config.nim

@@ -27,6 +27,12 @@ type
   JsonSocketTranslatorArguments* {.preservesRecord: "json-socket-translator".} = object
     `field0`*: JsonSocketTranslatorArgumentsField0
 
+  RrdArgumentsField0* {.preservesDictionary.} = object
+    `dataspace`* {.preservesEmbedded.}: EmbeddedRef
+
+  RrdArguments* {.preservesRecord: "rrd".} = object
+    `field0`*: RrdArgumentsField0
+
   WebhooksArgumentsField0* {.preservesDictionary.} = object
     `endpoints`*: Table[seq[string], EmbeddedRef]
     `listen`*: Tcp
@@ -34,6 +40,12 @@ type
   WebhooksArguments* {.preservesRecord: "webhooks".} = object
     `field0`*: WebhooksArgumentsField0
 
+  FileSystemUsageArgumentsField0* {.preservesDictionary.} = object
+    `dataspace`* {.preservesEmbedded.}: EmbeddedRef
+
+  FileSystemUsageArguments* {.preservesRecord: "file-system-usage".} = object
+    `field0`*: FileSystemUsageArgumentsField0
+
   SqliteArgumentsField0* {.preservesDictionary.} = object
     `database`*: string
     `dataspace`* {.preservesEmbedded.}: EmbeddedRef
@@ -55,7 +67,9 @@ type
 proc `$`*(x: WebsocketArguments | JsonTranslatorArguments |
     JsonTranslatorConnected |
     JsonSocketTranslatorArguments |
+    RrdArguments |
     WebhooksArguments |
+    FileSystemUsageArguments |
     SqliteArguments |
     CacheArguments |
     Tcp): string =
@@ -64,7 +78,9 @@ proc `$`*(x: WebsocketArguments | JsonTranslatorArguments |
 proc encode*(x: WebsocketArguments | JsonTranslatorArguments |
     JsonTranslatorConnected |
     JsonSocketTranslatorArguments |
+    RrdArguments |
     WebhooksArguments |
+    FileSystemUsageArguments |
     SqliteArguments |
     CacheArguments |
     Tcp): seq[byte] =

src/schema/rrd.nim

@@ -0,0 +1,14 @@
+
+import
+  preserves
+
+type
+  RRDaction* {.preservesRecord: "rrd".} = object
+    `verb`*: Symbol
+    `args`*: seq[string]
+
+proc `$`*(x: RRDaction): string =
+  `$`(toPreserves(x))
+
+proc encode*(x: RRDaction): seq[byte] =
+  encode(toPreserves(x))

src/syndesizer.nim

@@ -7,8 +7,10 @@ import syndicate, syndicate/relays, syndicate/actors/timers
 
 import ./syndesizer/[
   cache_actor,
+  file_system_usage,
   json_socket_translator,
   json_translator,
+  rrd,
   sqlite_actor,
   webhooks,
   websockets]
@@ -17,9 +19,12 @@ runActor("syndesizer") do (turn: var Turn; root: Cap):
   connectStdio(turn, root)
   discard spawnTimers(turn, root)
   discard spawnCacheActor(turn, root)
+  discard spawnFileSystemUsageActor(turn, root)
   discard spawnJsonSocketTranslator(turn, root)
   discard spawnJsonStdioTranslator(turn, root)
   discard spawnWebhookActor(turn, root)
   discard spawnWebsocketActor(turn, root)
+  when withLibrrd:
+    discard spawnRrdActor(turn, root)
   when withSqlite:
     discard spawnSqliteActor(turn, root)

src/syndesizer/file_system_usage.nim

@@ -0,0 +1,27 @@
+# SPDX-FileCopyrightText: ☭ Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+import std/[dirs, os, paths]
+import preserves
+import syndicate, syndicate/relays
+
+import ../schema/[assertions, config]
+
+proc spawnFileSystemUsageActor*(turn: var Turn; root: Cap): Actor {.discardable.} =
+  spawn("file-system-usage", turn) do (turn: var Turn):
+    during(turn, root, ?:FileSystemUsageArguments) do (ds: Cap):
+      var pat = ?Observe(pattern: !FileSystemUsage) ?? { 0: grab() }
+      during(turn, ds, pat) do (lit: Literal[string]):
+        var ass = FileSystemUsage(path: lit.value)
+        if fileExists(ass.path): ass.size = getFileSize(ass.path)
+        else:
+          for fp in walkDirRec(paths.Path(lit.value), yieldFilter={pcFile}):
+            var fs = getFileSize(string fp)
+            inc(ass.size, fs)
+        discard publish(turn, ds, ass)
+          # TODO: updates?
+
+when isMainModule:
+  runActor("main") do (turn: var Turn; root: Cap):
+    connectStdio(turn, root)
+    discard spawnFileSystemUsageActor(turn, root)

src/syndesizer/rrd.nim

@@ -0,0 +1,33 @@
+# SPDX-FileCopyrightText: ☭ Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+const withLibrrd* {.booldefine.}: bool = true
+
+when withLibrrd:
+  import preserves, syndicate, syndicate/relays
+  import ../schema/[config, rrd]
+
+  {.passC: staticExec("pkg-config --cflags librrd").}
+  {.passL: staticExec("pkg-config --libs librrd").}
+
+  {.pragma: librrd, header: "rrd.h", importc.}
+
+  proc rrd_update(a1: cint; a2: cstringArray): cint {.librrd.}
+  proc rrd_get_error(): cstring {.librrd.}
+  proc rrd_clear_error() {.librrd.}
+
+  proc spawnRrdActor*(turn: var Turn; root: Cap): Actor {.discardable.} =
+    spawn("rrd-actor", turn) do (turn: var Turn):
+      during(turn, root, ?:RrdArguments) do (ds: Cap):
+        let updatePattern = RRDaction ?: {0: ?Symbol"update", 1: grab()}
+        onMessage(turn, ds, updatePattern) do (args: seq[string]):
+          var argv = allocCStringArray(args)
+          if rrd_update(args.len.cint, argv) != 0:
+            stderr.writeLine(rrd_get_error())
+            rrd_clear_error()
+          deallocCStringArray(argv)
+
+  when isMainModule:
+    runActor("main") do (turn: var Turn; root: Cap):
+      connectStdio(turn, root)
+      spawnRrdActor(turn, root)