Initial work on pipelines

tests/test_pipelines.nim

@@ -0,0 +1,54 @@
+import
+  std/[unittest, strutils, base64],
+  ../faststreams/pipelines,
+  ./base64 as fsBase64
+
+include system/timers
+
+type
+  TestTimes = object
+    fsPipeline: Nanos
+    fsAsyncPipeline: Nanos
+    stdFunctionCalls: Nanos
+
+proc upcaseAllCharacters(i: InputStream, o: OutputStream) =
+  while i.readable:
+    o.append toUpperAscii(char i.read())
+
+template timeit(timerVar: var Nanos, code: untyped) =
+  let t0 = getTicks()
+  code
+  timerVar = int(getTicks() - t0) div 1000000
+
+suite "pipelines":
+  var loremIpsum = """
+    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
+    tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
+    veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex
+    ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
+    velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat
+    cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id
+    est laborum.
+
+  """.repeat(100)
+
+  test "upper-case/base64 pipeline":
+    var
+      times: TestTimes
+      stdRes: string
+      fsRes: string
+
+    timeIt times.fsPipeline:
+      var memOut = memoryOutput()
+      executePipeline(memoryInput(loremIpsum),
+                      upcaseAllCharacters,
+                      base64encode,
+                      base64decode,
+                      memOut)
+      fsRes = memOut.getOutput(string)
+
+    timeIt times.stdFunctionCalls:
+      stdRes = base64.decode(base64.encode(toUpperAscii(loremIpsum)))
+
+    check fsRes == stdRes
+