Make various trace methods take last_lines argument:

So that we could read last few lines rather than read
the entire file which could be huge.

1 files changed, 11 insertions, 9 deletions

diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index f9aa1984c1f..13f101cbecb 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -128,13 +128,14 @@ module Ci
       latest_builds.where('stage_idx < ?', stage_idx)
     end
 
-    def trace_html
-      trace_with_state[:html] || ''
+    def trace_html(**args)
+      trace_with_state(**args)[:html] || ''
     end
 
-    def trace_with_state(state = nil)
-      if trace.present?
-        Ci::Ansi2html.convert(trace, state)
+    def trace_with_state(state: nil, last_lines: nil)
+      trace_ansi = trace(last_lines)
+      if trace_ansi.present?
+        Ci::Ansi2html.convert(trace_ansi, state)
       else
         {}
       end
@@ -220,9 +221,10 @@ module Ci
       raw_trace.present?
     end
 
-    def raw_trace
+    def raw_trace(last_lines: nil)
       if File.exist?(trace_file_path)
-        File.read(trace_file_path)
+        Gitlab::Ci::TraceReader.new(trace_file_path).
+          read(last_lines: last_lines)
       else
         # backward compatibility
         read_attribute :trace
@@ -237,8 +239,8 @@ module Ci
       project.ci_id && File.exist?(old_path_to_trace)
     end
 
-    def trace
-      result = raw_trace
+    def trace(last_lines: nil)
+      result = raw_trace(last_lines)
       if project && result.present? && project.runners_token.present?
         result.gsub(project.runners_token, 'xxxxxx')
       else