Refactors TimedLogger to be more OOP compliant

Adds a #full_message method so that external classes
do not have access to the state of the logger.

Adds a #append_message to always append to the array in-place

lib/gitlab/checks/change_access.rb

@@ -47,7 +47,7 @@ module Gitlab
         @protocol = protocol
 
         @logger = logger
-        @logger.log << "Running checks for ref: #{@branch_name || @tag_name}"
+        @logger.append_message("Running checks for ref: #{@branch_name || @tag_name}")
       end
 
       def exec(skip_commits_check: false)

lib/gitlab/checks/timed_logger.rb

@@ -5,15 +5,18 @@ module Gitlab
     class TimedLogger
       TimeoutError = Class.new(StandardError)
 
-      attr_reader :start_time
-      attr_accessor :log, :timeout
+      attr_reader :start_time, :header, :log, :timeout
 
-      def initialize(start_time: Time.now, log: [], timeout:)
+      def initialize(start_time: Time.now, log: [], timeout:, header: "")
         @start_time = start_time
         @timeout = timeout
+        @header = header
         @log = log
       end
 
+      # Adds trace of method being tracked with
+      # the correspondent time it took to run it
+      #
       def log_timed(log_message, start = Time.now)
         check_timeout_reached
 
@@ -21,12 +24,12 @@ module Gitlab
 
         yield
 
-        log << log_message + time_suffix_message(start: start)
+        append_message(log_message + time_suffix_message(start: start))
       rescue GRPC::DeadlineExceeded, TimeoutError
         args = { cancelled: true }
         args[:start] = start if timed
 
-        log << log_message + time_suffix_message(args)
+        append_message(log_message + time_suffix_message(args))
 
         raise TimeoutError
       end
@@ -41,6 +44,15 @@ module Gitlab
         (start_time + timeout.seconds) - Time.now
       end
 
+      def full_message
+        header + log.join("\n")
+      end
+
+      # We always want to append in-place on the log
+      def append_message(message)
+        log << message
+      end
+
       private
 
       def time_expired?

lib/gitlab/git_access.rb

@@ -27,6 +27,12 @@ module Gitlab
       cannot_push_to_read_only: "You can't push code to a read-only GitLab instance."
     }.freeze
 
+    LOG_HEADER = <<~MESSAGE
+      Push operation timed out
+
+      Timing information for debugging purposes:
+    MESSAGE
+
     INTERNAL_TIMEOUT = 50.seconds.freeze
     DOWNLOAD_COMMANDS = %w{git-upload-pack git-upload-archive}.freeze
     PUSH_COMMANDS = %w{git-receive-pack}.freeze
@@ -46,7 +52,7 @@ module Gitlab
     end
 
     def check(cmd, changes)
-      @logger = Checks::TimedLogger.new(timeout: INTERNAL_TIMEOUT)
+      @logger = Checks::TimedLogger.new(timeout: INTERNAL_TIMEOUT, header: LOG_HEADER)
       @changes = changes
 
       check_protocol!
@@ -284,13 +290,7 @@ module Gitlab
 
       change_access.exec
     rescue Checks::TimedLogger::TimeoutError
-      header = <<~MESSAGE
-      Push operation timed out
-
-      Timing information for debugging purposes:
-      MESSAGE
-
-      raise TimeoutError, header + logger.log.join("\n")
+      raise TimeoutError, logger.full_message
     end
 
     def deploy_key