Merge branch 'smarter-cache-invalidation' into 'master'

Smarter cache invalidation

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/23550

See merge request !7360

1 files changed, 63 insertions, 0 deletions

diff --git a/lib/gitlab/file_detector.rb b/lib/gitlab/file_detector.rb
new file mode 100644
index 00000000000..1d93a67dc56
--- /dev/null
+++ b/lib/gitlab/file_detector.rb
@@ -0,0 +1,63 @@
+require 'set'
+
+module Gitlab
+  # Module that can be used to detect if a path points to a special file such as
+  # a README or a CONTRIBUTING file.
+  module FileDetector
+    PATTERNS = {
+      readme: /\Areadme/i,
+      changelog: /\A(changelog|history|changes|news)/i,
+      license: /\A(licen[sc]e|copying)(\..+|\z)/i,
+      contributing: /\Acontributing/i,
+      version: 'version',
+      gitignore: '.gitignore',
+      koding: '.koding.yml',
+      gitlab_ci: '.gitlab-ci.yml',
+      avatar: /\Alogo\.(png|jpg|gif)\z/
+    }
+
+    # Returns an Array of file types based on the given paths.
+    #
+    # This method can be used to check if a list of file paths (e.g. of changed
+    # files) involve any special files such as a README or a LICENSE file.
+    #
+    # Example:
+    #
+    #     types_in_paths(%w{README.md foo/bar.txt}) # => [:readme]
+    def self.types_in_paths(paths)
+      types = Set.new
+
+      paths.each do |path|
+        type = type_of(path)
+
+        types << type if type
+      end
+
+      types.to_a
+    end
+
+    # Returns the type of a file path, or nil if none could be detected.
+    #
+    # Returned types are Symbols such as `:readme`, `:version`, etc.
+    #
+    # Example:
+    #
+    #     type_of('README.md') # => :readme
+    #     type_of('VERSION') # => :version
+    def self.type_of(path)
+      name = File.basename(path)
+
+      PATTERNS.each do |type, search|
+        did_match = if search.is_a?(Regexp)
+                      name =~ search
+                    else
+                      name.casecmp(search) == 0
+                    end
+
+        return type if did_match
+      end
+
+      nil
+    end
+  end
+end