Clarify Cache interface

Author: root

Diff for: app/models/concerns/gitolitable_cache.rb

@@ -59,6 +59,7 @@ def find_by_path(path, flags = {})
 
   # If repo identifiers unique, identifier forms unique label
   # Else, use directory notation: <project identifier>/<repo identifier>
+  #
   def git_cache_id
     if identifier.blank?
       # Should only happen with one repo/project (the default)
@@ -71,9 +72,10 @@ def git_cache_id
   end
 
 
-  # Note: CacheManager doesn't know about repository object, it only know git_cache_id.
+  # Note: RedmineGitHosting::Cache doesn't know about repository object, it only knows git_cache_id.
+  #
   def empty_cache!
-    RedmineGitHosting::CacheManager.clear_cache_for_repository(git_cache_id)
+    RedmineGitHosting::Cache.clear_cache_for_repository(git_cache_id)
   end
 
 end

Diff for: app/use_cases/apply_settings.rb

@@ -107,7 +107,7 @@ def check_hooks_install
 
     def check_cache_config
       ## Gitolite cache has changed, clear cache entries!
-      RedmineGitHosting::CacheManager.clear_obsolete_cache_entries if value_has_changed?(:gitolite_cache_max_time)
+      RedmineGitHosting::Cache.clear_obsolete_cache_entries if value_has_changed?(:gitolite_cache_max_time)
     end
 
 

Diff for: lib/redmine_git_hosting/cache.rb

@@ -0,0 +1,128 @@
+module RedmineGitHosting
+  module Cache
+
+    class << self
+
+      def max_cache_time
+        RedmineGitHosting::Config.gitolite_cache_max_time
+      end
+
+
+      def max_cache_elements
+        RedmineGitHosting::Config.gitolite_cache_max_elements
+      end
+
+
+      # Used in ShellRedirector but define here to keep a clean interface.
+      def max_cache_size
+        RedmineGitHosting::Config.gitolite_cache_max_size
+      end
+
+
+      def set_cache(repo_id, out_value, primary_key, secondary_key = nil)
+        logger.debug("Inserting cache entry for repository '#{repo_id}'")
+        logger.debug(compose_key(primary_key, secondary_key))
+        command = compose_key(primary_key, secondary_key)
+        set_cache_entry(command, out_value, repo_id)
+      end
+
+
+      def check_cache(primary_key, secondary_key = nil)
+        cached = get_cache_entry(primary_key, secondary_key)
+
+        if cached
+          if valid_cache_entry?(cached)
+            # Update updated_at flag
+            cached.touch unless cached.command_output.nil?
+            out = cached.command_output
+          else
+            cached.destroy
+            out = nil
+          end
+        else
+          out = nil
+        end
+
+        # Return result as a string stream
+        out.nil? ? nil : StringIO.new(out)
+      end
+
+
+      # After resetting cache timing parameters -- delete entries that no-longer match
+      def clear_obsolete_cache_entries
+        return if max_cache_time < 0  # No expiration needed
+        limit = Time.now - max_cache_time
+        do_clear_obsolete_cache_entries(limit)
+      end
+
+
+      # Clear the cache entries for given repository / git_cache_id
+      def clear_cache_for_repository(repo_id)
+        do_clear_cache_for_repository(repo_id)
+      end
+
+
+      private
+
+
+        def set_cache_entry(command, output, repo_id)
+          begin
+            GitCache.create(
+              command:         command,
+              command_output:  output,
+              repo_identifier: repo_id
+            )
+          rescue => e
+            logger.error("Could not insert in cache, this is the error : '#{e.message}'")
+          else
+            apply_cache_limit
+          end
+        end
+
+
+        def get_cache_entry(primary_key, secondary_key)
+          GitCache.find_by_command(compose_key(primary_key, secondary_key))
+        end
+
+
+        def valid_cache_entry?(cached)
+          current_time = ActiveRecord::Base.default_timezone == :utc ? Time.now.utc : Time.now
+          expired = (current_time.to_i - cached.created_at.to_i < max_cache_time)
+          (!expired || max_cache_time < 0) ? true : false
+        end
+
+
+        def apply_cache_limit
+          GitCache.find(:last, order: 'created_at DESC').destroy if max_cache_elements >= 0 && GitCache.count > max_cache_elements
+        end
+
+
+        def compose_key(key1, key2)
+          if key2 && !key2.blank?
+            key1 + "\n" + key2
+          else
+            key1
+          end
+        end
+
+
+        def do_clear_obsolete_cache_entries(limit)
+          deleted = GitCache.delete_all(['created_at < ?', limit])
+          logger.info("Removed '#{deleted}' expired cache entries among all repositories")
+        end
+
+
+        def do_clear_cache_for_repository(repo_id)
+          deleted = GitCache.delete_all(['repo_identifier = ?', repo_id])
+          logger.info("Removed '#{deleted}' expired cache entries for repository '#{repo_id}'")
+        end
+
+
+        def logger
+          RedmineGitHosting.logger
+        end
+
+    end
+
+  end
+end

Diff for: lib/redmine_git_hosting/cache_manager.rb

@@ -49,7 +49,7 @@ def git_cmd_with_git_hosting(args, options = {}, &block)
 
             if !git_cache_id.nil? && git_cache_enabled?
               # Insert cache between shell execution and caller
-              RedmineGitHosting::CacheManager.execute(cmd_str, git_cache_id, options, &block)
+              RedmineGitHosting::ShellRedirector.execute(cmd_str, git_cache_id, options, &block)
             else
               Redmine::Scm::Adapters::AbstractAdapter.shellout(cmd_str, options, &block)
             end

Diff for: lib/redmine_git_hosting/patches/xitolite_adapter_patch.rb

@@ -24,7 +24,7 @@ def move_repository_to_recycle
 
       def remove_git_cache
         logger.info("Clean cache for repository '#{gitolite_repo_name}'")
-        RedmineGitHosting::CacheManager.clear_cache_for_repository(git_cache_id)
+        RedmineGitHosting::Cache.clear_cache_for_repository(git_cache_id)
       end
 
   end