resdir: cache contents on creation, serve case-insensitive, fixes #104

neverwinter/resdir.nim

@@ -1,31 +1,55 @@
 ## A Resdir is the contents of a single directory mapped into resman. The contents
-## are available live (meaning that adding files makes them available immediately).
-## This may change in the future.
+## are cached on creation and additions to the local filesystem are not reflected.
 
-import streams, os
+import std/[streams, os, tables, logging]
 
 import resman
 
 type
   ResDir* = ref object of ResContainer
     directory: string
+    contentMap: Table[ResRef, string]
+    contentSet: OrderedSet[ResRef]
+
+proc rebuild(self: ResDir) =
+  assert(self.directory != "")
+  self.contentMap.clear()
+  self.contentSet.clear()
+  for pc in walkDir(self.directory, relative = true):
+    if pc.kind in {pcFile, pcLinkToFile}:
+      let rr = tryNewResolvedResRef(pc.path)
+      if rr.isSome:
+        self.contentMap[rr.unsafeGet] = pc.path
+        self.contentSet.incl(rr.unsafeGet)
 
 proc newResDir*(directory: string): ResDir =
   new(result)
   result.directory = directory
+  result.rebuild()
 
 proc directory*(self: ResDir): string =
   self.directory
 
-proc resRefToFullPath(self: ResDir, rr: ResolvedResRef): string =
-  self.directory & DirSep & rr.toFile
+proc checkExists(self: ResDir, rr: ResRef): bool =
+  if not self.contentSet.contains(rr):
+    return false
+
+  if not fileExists(self.directory / self.contentMap[rr]):
+    debug self, ": ", rr, " disappeared since ResDir creation"
+    self.contentMap.del(rr)
+    self.contentSet.excl(rr)
+    return false
+
+  return true
 
 method contains*(self: ResDir, rr: ResRef): bool =
-  let r = rr.resolve()
-  result = r.isSome and fileExists(self.resRefToFullPath(r.get()))
+  self.checkExists(rr)
 
 method demand*(self: ResDir, rr: ResRef): Res =
-  let fp = self.resRefToFullPath(rr.resolve().get())
+  if not self.checkExists(rr):
+    return nil
+
+  let fp = self.directory / self.contentMap[rr]
   let mtime = getLastModificationTime(fp)
   let sz = getFileSize(fp).int
 
@@ -38,15 +62,7 @@ method count*(self: ResDir): int =
   self.contents.card
 
 method contents*(self: ResDir): OrderedSet[ResRef] =
-  result = initOrderedSet[ResRef]()
-
-  for pc in walkDir(self.directory, true):
-    if (pc.kind == pcFile or pc.kind == pcLinkToFile):
-      let rr = tryNewResolvedResRef(pc.path)
-      if rr.isSome:
-        # if pc.path != pc.path.toLowerAscii:
-        #   warn self, ": '" & pc.path & "' is not lowercase. This will break on Linux."
-        result.incl(rr.get())
+  self.contentSet
 
 method `$`*(self: ResDir): string =
   "ResDir:" & self.directory

tests/resman/corpus_uc/SAMPLE.txt

@@ -0,0 +1 @@
+OLLEH

tests/resman/tcase.nim

@@ -0,0 +1,18 @@
+import std/[os, strutils]
+import neverwinter/[resman, resdir]
+
+let rr = newResolvedResRef("SAMPLE.txt")
+var rm = newResMan(0)
+
+const sourceDir = currentSourcePath().splitFile().dir
+
+rm.add newResDir(sourceDir / "corpus")
+rm.add newResDir(sourceDir / "corpus_uc")
+
+let rd = rm.demand(rr, useCache=false)
+
+# The uppercase file must override the lowercase variant further up the stack
+# (the uppercase variant contains OLLEH, the lowercase variant HELLO)
+# This test will only be effective on case-sensitive file sytems.
+let check = rd.readAll().strip()
+doAssert check == "OLLEH", "got: " & check