From 37d2c8c06bce01f79b4cb74d9bc275f22f676750 Mon Sep 17 00:00:00 2001
From: Jaremy Creechley <creechley@gmail.com>
Date: Thu, 24 Aug 2023 16:18:31 -0700
Subject: [PATCH] updates

---
 datastore.nimble            |  1 +
 datastore/threadbackend.nim | 40 ++++++++++++++++++++++++++++---------
 tests/exampletaskpool.nim   | 34 +++++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+), 9 deletions(-)
 create mode 100644 tests/exampletaskpool.nim

diff --git a/datastore.nimble b/datastore.nimble
index 6252c6d..e14bb51 100644
--- a/datastore.nimble
+++ b/datastore.nimble
@@ -13,6 +13,7 @@ requires "nim >= 1.2.0",
          "sqlite3_abi",
          "stew",
          "unittest2",
+         "patty",
          "upraises >= 0.1.0 & < 0.2.0"
 
 task coverage, "generates code coverage report":
diff --git a/datastore/threadbackend.nim b/datastore/threadbackend.nim
index 57a245d..27fe9c3 100644
--- a/datastore/threadbackend.nim
+++ b/datastore/threadbackend.nim
@@ -4,6 +4,8 @@ import pkg/chronos
 import pkg/questionable
 import pkg/questionable/results
 import pkg/upraises
+import pkg/taskpools
+import pkg/patty
 
 import ./key
 import ./query
@@ -14,9 +16,29 @@ export key, query
 
 push: {.upraises: [].}
 
+variant Shape:
+  Circle(r: float)
+  Rectangle(w: float, h: float)
+
 type
+  DatastoreBackend* {.pure.} = enum
+    FileSystem
+    SQlite
+
   ThreadDatastore* = ref object of Datastore
-    # stores*: Table[KeyBuffer, ThreadDatastore]
+    tp: Taskpool
+
+var backendDatastore {.threadvar.}: ref Datastore
+
+proc startupDatastore(backend: DatastoreBackend): bool =
+
+  case backend:
+  of FileSystem:
+    backendDatastore = FSDatastore.new(
+      root: string,
+      depth = 2,
+      caseSensitive = true,
+      ignoreProtected = false
 
 proc has*(
   self: ThreadDatastore,
@@ -86,20 +108,20 @@ proc put*(
 proc close*(
   self: ThreadDatastore
 ): Future[?!void] {.async.} =
-
-  # for s in self.stores.values:
-  #   discard await s.store.close()
-
-  # TODO: how to handle failed close?
+  self.tp.shutdown()
   return success()
 
 func new*[S: ref Datastore](
   T: typedesc[ThreadDatastore],
-  storeTp: typedesc[S]
+  backend: DatastoreBackend,
 ): ?!ThreadDatastore =
 
   var self = T()
-  # for (k, v) in stores.pairs:
-  #   self.stores[?k.path] = MountedStore(store: v, key: k)
+  self.tp = Taskpool.new(num_threads = 1) ##\
+    ## Default to one thread, multiple threads \
+    ## will require more work
+
+  let pending = self.tp.spawn startupDatastore(backend)
+  sync pending
 
   success self
diff --git a/tests/exampletaskpool.nim b/tests/exampletaskpool.nim
new file mode 100644
index 0000000..c410235
--- /dev/null
+++ b/tests/exampletaskpool.nim
@@ -0,0 +1,34 @@
+
+
+import
+  std/[strutils, math, cpuinfo],
+  taskpools
+
+# From https://github.com/nim-lang/Nim/blob/v1.6.2/tests/parallel/tpi.nim
+# Leibniz Formula https://en.wikipedia.org/wiki/Leibniz_formula_for_%CF%80
+proc term(k: int): float =
+  if k mod 2 == 1:
+    -4'f / float(2*k + 1)
+  else:
+    4'f / float(2*k + 1)
+
+proc piApprox(tp: Taskpool, n: int): float =
+  var pendingFuts = newSeq[FlowVar[float]](n)
+  for k in 0 ..< pendingFuts.len:
+    pendingFuts[k] = tp.spawn term(k) # Schedule a task on the threadpool a return a handle to retrieve the result.
+  for k in 0 ..< pendingFuts.len:
+    result += sync pendingFuts[k]     # Block until the result is available.
+
+proc main() =
+  var n = 1_000_000
+  var nthreads = countProcessors()
+
+  var tp = Taskpool.new(num_threads = nthreads) # Default to the number of hardware threads.
+
+  echo formatFloat(tp.piApprox(n))
+
+  tp.syncAll()                                  # Block until all pending tasks are processed (implied in tp.shutdown())
+  tp.shutdown()
+
+# Compile with nim c -r -d:release --threads:on --outdir:build example.nim
+main()
\ No newline at end of file