integrate Gollum::GitAccess

lib/gollum/git_access.rb

@@ -2,18 +2,108 @@ module Gollum
   class GitAccess
     attr_reader :path
     attr_reader :repo
+
+    # Gets a Hash cache of refs to commit SHAs.
+    #
+    #   {"master" => "abc123", ...}
+    #
+    # Returns the Hash cache.
     attr_reader :ref_map
+
+    # Gets a Hash cache of commit SHAs to a recursive tree of blobs.
+    #
+    #   {"abc123" => [["lib/foo.rb", "blob-sha"], [file, sha], ...], ...}
+    #
+    # Returns the Hash cache.
     attr_reader :tree_map
+    attr_reader :commit_map
 
     def initialize(path)
-      @path     = path
-      @repo     = Grit::Repo.new(path)
-      @ref_map  = {}
-      @tree_map = {}
+      @path = path
+      @repo = Grit::Repo.new(path)
+      clear
+    end
+
+    def clear
+      @ref_map    = {}
+      @tree_map   = {}
+      @commit_map = {}
+    end
+
+    def refresh
+      @ref_map.clear
     end
 
     def exist?
       @repo.git.exist?
     end
+
+    def ref_to_sha(ref)
+      @ref_map[ref] ||= ref_to_sha!(ref)
+    end
+
+    def tree(ref)
+      sha = ref_to_sha(ref)
+      @tree_map[sha] ||= tree!(sha)
+    end
+
+    def blob(sha)
+      cat_file!(sha)
+    end
+
+    def commit(ref)
+      if sha = @ref_map[ref]
+        @commit_map[sha] ||= commit!(sha)
+      else
+        cm = commit!(ref)
+        @ref_map[ref]      = cm.id
+        @commit_map[cm.id] = cm
+      end
+    end
+
+    def ref_to_sha!(ref)
+      @repo.git.rev_list({:max_count=>1}, ref)
+    end
+
+    def tree!(sha)
+      tree  = @repo.git.native(:ls_tree, 
+        {:r => true, :l => true, :z => true}, sha)
+      tree.split("\0").inject([]) do |items, line|
+        items << parse_tree_line(line)
+      end
+    end
+
+    def cat_file!(sha)
+      @repo.git.cat_file({:p => true}, sha)
+    end
+
+    def commit!(sha)
+      @repo.commit(sha)
+    end
+
+    # Parses a line of output from the `ls-tree` command.
+    #
+    # line - A String line of output:
+    #          "100644 blob 839c2291b30495b9a882c17d08254d3c90d8fb53	Home.md"
+    #
+    # Returns an Array of BlobEntry instances.
+    def parse_tree_line(line)
+      mode, type, sha, size, *name = line.split(/\s+/)
+      BlobEntry.new(sha, name.to_s, size.to_i)
+    end
+
+    # Decode octal sequences (\NNN) in tree path names.
+    #
+    # path - String path name.
+    #
+    # Returns a decoded String.
+    def decode_git_path(path)
+      if path[0] == ?" && path[-1] == ?"
+        path = path[1...-1]
+        path.gsub!(/\\\d{3}/)   { |m| m[1..-1].to_i(8).chr }
+      end
+      path.gsub!(/\\[rn"\\]/) { |m| eval(%("#{m.to_s}")) }
+      path
+    end
   end
 end