[FileCache#Find] N to 1 calls for file matching

lib/chef/file_cache.rb

@@ -159,9 +159,24 @@ def list
       # [String] - An array of file cache keys matching the glob
       def find(glob_pattern)
         keys = []
-        Dir[File.join(Chef::Util::PathHelper.escape_glob_dir(file_cache_path), glob_pattern)].each do |f|
+        file_cache_dir = Chef::Util::PathHelper.escape_glob_dir(file_cache_path)
+        first_filename = Dir[file_cache_dir].first # directory of the cache
+        return keys unless first_filename
+
+        # TODO: The usage of Regexp.escape and the match here is likely
+        # vestigial, but since it's only getting called once per method, the
+        # effort needed to confirm that its removal won't break something else
+        # isn't worth it. A task for a brave soul ;-)
+        regexp_pattern = /^(#{Regexp.escape(first_filename) + File::Separator}).+/
+
+        files = Dir[File.join(file_cache_dir, glob_pattern)]
+        until files.empty?
+          f = files.shift
           if File.file?(f)
-            keys << f[/^#{Regexp.escape(Dir[Chef::Util::PathHelper.escape_glob_dir(file_cache_path)].first) + File::Separator}(.+)/, 1]
+            # We remove the cache directory from the string of each entry
+            path_to_remove ||= f[regexp_pattern, 1]
+            f.delete_prefix!(path_to_remove)
+            keys << f
           end
         end
         keys

spec/unit/file_cache_spec.rb

@@ -94,7 +94,71 @@
     it "searches for cached files by globbing" do
       expect(Chef::FileCache.find("snappy/**/*")).to eq(%w{snappy/patter})
     end
+  end
+
+  describe "#find handles regex-unsafe unix paths" do
+    before(:each) do
+      # Dir.mktmpdir doesn't allow regex unsafe characters (the nerve!), so we'll have to fake file lookups
+      @file_cache_path = "/tmp/[foo* ^bar]"
+      escaped_file_cache_path = '/tmp/\[foo\* ^bar\]'
+      Chef::Config[:file_cache_path] = @file_cache_path
+      allow(Chef::Util::PathHelper).to receive(:escape_glob_dir).and_return(escaped_file_cache_path)
+      allow(Dir).to receive(:[]).with(File.join(escaped_file_cache_path, "snappy/**/*")).and_return([
+        File.join(@file_cache_path, "snappy"),
+        File.join(@file_cache_path, "snappy", "patter"),
+      ])
+      allow(Dir).to receive(:[]).with(escaped_file_cache_path).and_return([
+        @file_cache_path,
+      ])
+      [
+        File.join(@file_cache_path, "snappy", "patter"),
+        File.join(@file_cache_path, "whiz", "bang"),
+      ].each do |f|
+        allow(File).to receive(:file?).with(f).and_return(true)
+      end
+      [
+        File.join(@file_cache_path, "snappy"),
+        File.join(@file_cache_path, "whiz"),
+      ].each do |f|
+        allow(File).to receive(:file?).with(f).and_return(false)
+      end
+    end
+
+    it "searches for cached files by globbing" do
+      expect(Chef::FileCache.find("snappy/**/*")).to eq(%w{snappy/patter})
+    end
+  end
 
+  describe "#find handles Windows paths" do
+    before(:each) do
+      allow(ChefUtils).to receive(:windows?).and_return(true)
+      @file_cache_path = 'C:\tmp\fakecache'
+      escaped_file_cache_path = "C:\\tmp\\fakecache"
+      Chef::Config[:file_cache_path] = @file_cache_path
+      allow(Chef::Util::PathHelper).to receive(:escape_glob_dir).and_return(escaped_file_cache_path)
+      allow(Dir).to receive(:[]).with(File.join(escaped_file_cache_path, "snappy/**/*")).and_return([
+        File.join(@file_cache_path, "snappy"),
+        File.join(@file_cache_path, "snappy", "patter"),
+      ])
+      allow(Dir).to receive(:[]).with(escaped_file_cache_path).and_return([
+        @file_cache_path,
+      ])
+      [
+        File.join(@file_cache_path, "snappy", "patter"),
+        File.join(@file_cache_path, "whiz", "bang"),
+      ].each do |f|
+        allow(File).to receive(:file?).with(f).and_return(true)
+      end
+      [
+        File.join(@file_cache_path, "snappy"),
+        File.join(@file_cache_path, "whiz"),
+      ].each do |f|
+        allow(File).to receive(:file?).with(f).and_return(false)
+      end
+    end
+    it "searches for cached files by globbing" do
+      expect(Chef::FileCache.find("snappy/**/*")).to eq(%w{snappy/patter})
+    end
   end
 
   describe "when checking for the existence of a file" do