Extract implementation of fileType-based tree filter out of JGitSnapshot.HEADmaster

Such a filter is general enough that it's better to extract it it's own
object so it can be reused.

Change-Id: I30635577f6d1ca8dbfacec99c85de9919451a9da
Signed-off-by: Grzegorz Kossakowski <grzegorz.kossakowski@gmail.com>

2 files changed, 39 insertions, 17 deletions

diff --git a/src/main/scala/com/google/gimd/jgit/FileTypeTreeFilter.scala b/src/main/scala/com/google/gimd/jgit/FileTypeTreeFilter.scala
new file mode 100644
index 0000000..217c693
--- /dev/null
+++ b/src/main/scala/com/google/gimd/jgit/FileTypeTreeFilter.scala
@@ -0,0 +1,38 @@
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.gimd.jgit
+
+import org.spearce.jgit.lib.FileMode
+import com.google.gimd.file.FileType
+import org.spearce.jgit.treewalk.filter.{AndTreeFilter, PathFilter, PathSuffixFilter, TreeFilter}
+import org.spearce.jgit.treewalk.TreeWalk
+
+
+object FileTypeTreeFilter {
+
+  def apply[T](fileType: FileType[T]): TreeFilter =
+    AndTreeFilter.create(
+      Array(
+        RegularFileFilter,
+        fileType.pathPrefix.map(PathFilter.create(_)).getOrElse(TreeFilter.ALL),
+        fileType.pathSuffix.map(PathSuffixFilter.create(_)).getOrElse(TreeFilter.ALL)
+      )
+    )
+
+  private object RegularFileFilter extends TreeFilter {
+    def shouldBeRecursive = false
+    def include(treeWalk: TreeWalk) =
+      treeWalk.isSubtree || FileMode.REGULAR_FILE.equals(treeWalk.getFileMode(0))
+    override def clone = this
+  }
+
+}
diff --git a/src/main/scala/com/google/gimd/jgit/JGitSnapshot.scala b/src/main/scala/com/google/gimd/jgit/JGitSnapshot.scala
index 094577a..ab1e7d3 100644
--- a/src/main/scala/com/google/gimd/jgit/JGitSnapshot.scala
+++ b/src/main/scala/com/google/gimd/jgit/JGitSnapshot.scala
@@ -27,7 +27,7 @@ final class JGitSnapshot(val branch: JGitBranch, val commit: RevCommit) extends
     val treeWalk = new TreeWalk(branch.repository)
     treeWalk.reset(commit.getTree)
     treeWalk.setRecursive(true)
-    treeWalk.setFilter(treeFilter(fileType))
+    treeWalk.setFilter(FileTypeTreeFilter(fileType))
 
     val fileIterator = new Iterator[File[T]] {
       private var doesHasNext = treeWalk.next
@@ -44,20 +44,4 @@ final class JGitSnapshot(val branch: JGitBranch, val commit: RevCommit) extends
     fileIterator
   }
 
-  private def treeFilter[T](fileType: FileType[T]): TreeFilter =
-    AndTreeFilter.create(
-      Array(
-        RegularFileFilter,
-        fileType.pathPrefix.map(PathFilter.create(_)).getOrElse(TreeFilter.ALL),
-        fileType.pathSuffix.map(PathSuffixFilter.create(_)).getOrElse(TreeFilter.ALL)
-      )
-    )
-
-  private object RegularFileFilter extends TreeFilter {
-    def shouldBeRecursive = false
-    def include(treeWalk: TreeWalk) =
-      treeWalk.isSubtree || FileMode.REGULAR_FILE.equals(treeWalk.getFileMode(0))
-    override def clone = this
-  }
-
 }