From 1876043dae48ad6a97fe1cc5ad2643f83658ecf2 Mon Sep 17 00:00:00 2001
From: Hunter Haugen <hunter@puppet.com>
Date: Fri, 11 May 2018 14:29:30 -0700
Subject: [PATCH] Remove threading and use caching

The octo_fetcher caches the commits, so removing the threading around
methods requesting commits from the cache reduces CPU time and memory
usage.

Closes #651
---
 .../generator/generator_fetcher.rb            | 28 ++++++-------------
 .../octo_fetcher.rb                           |  9 +++---
 2 files changed, 14 insertions(+), 23 deletions(-)

diff --git a/lib/github_changelog_generator/generator/generator_fetcher.rb b/lib/github_changelog_generator/generator/generator_fetcher.rb
index 22dc1c93b..fabe6ef3b 100644
--- a/lib/github_changelog_generator/generator/generator_fetcher.rb
+++ b/lib/github_changelog_generator/generator/generator_fetcher.rb
@@ -18,34 +18,24 @@ def fetch_events_for_issues_and_pr
     # Async fetching of all tags dates
     def fetch_tags_dates(tags)
       print "Fetching tag dates...\r" if options[:verbose]
-      # Async fetching tags:
-      threads = []
       i = 0
-      all = tags.count
       tags.each do |tag|
-        print "                                 \r"
-        threads << Thread.new do
-          get_time_of_tag(tag)
-          print "Fetching tags dates: #{i + 1}/#{all}\r" if options[:verbose]
-          i += 1
-        end
+        get_time_of_tag(tag)
+        i += 1
       end
-      threads.each(&:join)
-      puts "Fetching tags dates: #{i}" if options[:verbose]
+      puts "Fetching tags dates: #{i}/#{tags.count}" if options[:verbose]
     end
 
     # Find correct closed dates, if issues was closed by commits
     def detect_actual_closed_dates(issues)
       print "Fetching closed dates for issues...\r" if options[:verbose]
 
-      issues.each_slice(MAX_THREAD_NUMBER) do |issues_slice|
-        threads = []
-        issues_slice.each do |issue|
-          threads << Thread.new { find_closed_date_by_commit(issue) }
-        end
-        threads.each(&:join)
+      i = 0
+      issues.each do |issue|
+        find_closed_date_by_commit(issue)
+        i += 1
       end
-      puts "Fetching closed dates for issues: Done!" if options[:verbose]
+      puts "Fetching closed dates for issues: #{i}/#{issues.count}" if options[:verbose]
     end
 
     # Adds a key "first_occurring_tag" to each PR with a value of the oldest
@@ -190,7 +180,7 @@ def set_date_from_event(event, issue)
         issue["actual_date"] = issue["closed_at"]
       else
         begin
-          commit = @fetcher.fetch_commit(event)
+          commit = @fetcher.fetch_commit(event["commit_id"])
           issue["actual_date"] = commit["commit"]["author"]["date"]
 
           # issue['actual_date'] = commit['author']['date']
diff --git a/lib/github_changelog_generator/octo_fetcher.rb b/lib/github_changelog_generator/octo_fetcher.rb
index 7466949b1..0204c99a6 100644
--- a/lib/github_changelog_generator/octo_fetcher.rb
+++ b/lib/github_changelog_generator/octo_fetcher.rb
@@ -238,7 +238,7 @@ def fetch_comments_async(prs)
     #
     # @return [Time] time of specified tag
     def fetch_date_of_tag(tag)
-      commit_data = check_github_response { @client.commit(user_project, tag["commit"]["sha"]) }
+      commit_data = fetch_commit(tag["commit"]["sha"])
       commit_data = stringify_keys_deep(commit_data.to_hash)
 
       commit_data["commit"]["committer"]["date"]
@@ -260,17 +260,18 @@ def fetch_compare(older, newer)
 
     # Fetch commit for specified event
     #
+    # @param [String] commit_id the SHA of a commit to fetch
     # @return [Hash]
-    def fetch_commit(event)
+    def fetch_commit(commit_id)
       found = commits.find do |commit|
-        commit["sha"] == event["commit_id"]
+        commit["sha"] == commit_id
       end
       if found
         stringify_keys_deep(found.to_hash)
       else
         # cache miss; don't add to @commits because unsure of order.
         check_github_response do
-          commit = @client.commit(user_project, event["commit_id"])
+          commit = @client.commit(user_project, commit_id)
           commit = stringify_keys_deep(commit.to_hash)
           commit
         end