From a1cddf051e6a4a2e0cb3a20efb9f323328fa4bce Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Sat, 6 May 2017 01:57:39 +0900
Subject: [PATCH 01/17] Reproduced

---
 spec/lib/gitlab/ci/trace/stream_spec.rb | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/spec/lib/gitlab/ci/trace/stream_spec.rb b/spec/lib/gitlab/ci/trace/stream_spec.rb
index 40ac5a3ed37..a607f000431 100644
--- a/spec/lib/gitlab/ci/trace/stream_spec.rb
+++ b/spec/lib/gitlab/ci/trace/stream_spec.rb
@@ -240,10 +240,18 @@ describe Gitlab::Ci::Trace::Stream do
     end
 
     context 'multiple results in content & regex' do
-      let(:data) { ' (98.39%) covered. (98.29%) covered' }
+      let(:data) do
+        <<~HEREDOC
+          (98.39%) covered
+          (98.29%) covered
+        HEREDOC
+      end
+
       let(:regex) { '\(\d+.\d+\%\) covered' }
 
-      it { is_expected.to eq("98.29") }
+      it 'returns the last matched coverage' do
+        is_expected.to eq("98.29")
+      end
     end
 
     context 'using a regex capture' do

From 6018afa89fc34b0ea9ba691e3690a9837fadc122 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Sat, 6 May 2017 03:16:39 +0900
Subject: [PATCH 02/17] Add reverse_line

---
 lib/gitlab/ci/trace/stream.rb | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index fa462cbe095..be8e40af016 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -73,7 +73,7 @@ module Gitlab
 
           match = ""
 
-          stream.each_line do |line|
+          reverse_line do |line|
             matches = line.scan(regex)
             next unless matches.is_a?(Array)
             next if matches.empty?
@@ -115,6 +115,26 @@ module Gitlab
 
           chunks.join.lines.last(last_lines).join
         end
+
+        def reverse_line
+          pos = 0
+          max = stream.size
+
+          while true
+            pos += BUFFER_SIZE
+
+            buf =
+              if pos <= max
+                stream.seek(-pos, IO::SEEK_END)
+                stream.read(BUFFER_SIZE)
+              else # Reached the head, read only left
+                stream.seek(0)
+                stream.read(BUFFER_SIZE - (pos - max))
+              end
+
+            yield(buf)
+          end
+        end
       end
     end
   end

From ddf67424ec5d84ff373e5e39195b5012c84eb920 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Sat, 6 May 2017 17:38:56 +0900
Subject: [PATCH 03/17] Fix while true

---
 lib/gitlab/ci/trace/stream.rb | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index be8e40af016..72a0d669de0 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -117,23 +117,18 @@ module Gitlab
         end
 
         def reverse_line
-          pos = 0
+          pos = BUFFER_SIZE
           max = stream.size
 
-          while true
+          while pos < max
+            stream.seek(-pos, IO::SEEK_END)
+            yield(stream.read(BUFFER_SIZE))
             pos += BUFFER_SIZE
-
-            buf =
-              if pos <= max
-                stream.seek(-pos, IO::SEEK_END)
-                stream.read(BUFFER_SIZE)
-              else # Reached the head, read only left
-                stream.seek(0)
-                stream.read(BUFFER_SIZE - (pos - max))
-              end
-
-            yield(buf)
           end
+
+          # Reached the head, read only left
+          stream.seek(0)
+          yield(stream.read(BUFFER_SIZE - (pos - max)))
         end
       end
     end

From 3d11b7d8e25ca39b347e61e12100c7745b6ea085 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 10 May 2017 02:40:34 +0900
Subject: [PATCH 04/17] Fix reverse_line from chunk based

---
 lib/gitlab/ci/trace/stream.rb           | 19 +++++++++++++++++--
 spec/lib/gitlab/ci/trace/stream_spec.rb | 22 ++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 72a0d669de0..546f6788a78 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -119,16 +119,31 @@ module Gitlab
         def reverse_line
           pos = BUFFER_SIZE
           max = stream.size
+          debris = ''
 
           while pos < max
             stream.seek(-pos, IO::SEEK_END)
-            yield(stream.read(BUFFER_SIZE))
+            stream.read(BUFFER_SIZE).tap do |buf|
+              buf = buf + debris
+              lines = buf.split("\n")
+              lines.reverse.each do |line|
+                yield(line)
+              end
+              debris = lines.count > 0 ? lines[0] : ''
+            end
             pos += BUFFER_SIZE
           end
 
           # Reached the head, read only left
           stream.seek(0)
-          yield(stream.read(BUFFER_SIZE - (pos - max)))
+          last = (max > BUFFER_SIZE) ? (max % BUFFER_SIZE) : max
+          stream.read(last).tap do |buf|
+            buf = buf + debris
+            lines = buf.split("\n")
+            lines.reverse.each do |line|
+              yield(line)
+            end
+          end
         end
       end
     end
diff --git a/spec/lib/gitlab/ci/trace/stream_spec.rb b/spec/lib/gitlab/ci/trace/stream_spec.rb
index a607f000431..d90ccf4f799 100644
--- a/spec/lib/gitlab/ci/trace/stream_spec.rb
+++ b/spec/lib/gitlab/ci/trace/stream_spec.rb
@@ -254,6 +254,28 @@ describe Gitlab::Ci::Trace::Stream do
       end
     end
 
+    context 'when BUFFER_SIZE is smaller than stream.size' do
+      let(:data) { 'Coverage 1033 / 1051 LOC (98.29%) covered\n' }
+      let(:regex) { '\(\d+.\d+\%\) covered' }
+
+      before do
+        stub_const('Gitlab::Ci::Trace::Stream::BUFFER_SIZE', 5)
+      end
+
+      it { is_expected.to eq("98.29") }
+    end
+
+    context 'when BUFFER_SIZE is equal to stream.size' do
+      let(:data) { 'Coverage 1033 / 1051 LOC (98.29%) covered\n' }
+      let(:regex) { '\(\d+.\d+\%\) covered' }
+
+      before do
+        stub_const('Gitlab::Ci::Trace::Stream::BUFFER_SIZE', data.length)
+      end
+
+      it { is_expected.to eq("98.29") }
+    end
+
     context 'using a regex capture' do
       let(:data) { 'TOTAL      9926   3489    65%' }
       let(:regex) { 'TOTAL\s+\d+\s+\d+\s+(\d{1,3}\%)' }

From 14c0833c1c9f1633ab6d3e791decd57eb7422c4f Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 10 May 2017 02:44:47 +0900
Subject: [PATCH 05/17] Add changelog

---
 changelogs/unreleased/31556-ci-coverage-paralel-rspec.yml | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 changelogs/unreleased/31556-ci-coverage-paralel-rspec.yml

diff --git a/changelogs/unreleased/31556-ci-coverage-paralel-rspec.yml b/changelogs/unreleased/31556-ci-coverage-paralel-rspec.yml
new file mode 100644
index 00000000000..4137050a077
--- /dev/null
+++ b/changelogs/unreleased/31556-ci-coverage-paralel-rspec.yml
@@ -0,0 +1,4 @@
+---
+title: Fix the last coverage in trace log should be extracted
+merge_request: 11128
+author: dosuken123

From b9950c22b38456537af92c77210f1b837bdc914c Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Tue, 16 May 2017 22:35:18 +0900
Subject: [PATCH 06/17] Use each_line. Avoid comparison of partial. Add UTF-8
 spec.

---
 lib/gitlab/ci/trace/stream.rb           |  8 +++-----
 spec/lib/gitlab/ci/trace/stream_spec.rb | 11 +++++++++++
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 546f6788a78..56d6855c3c6 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -125,11 +125,10 @@ module Gitlab
             stream.seek(-pos, IO::SEEK_END)
             stream.read(BUFFER_SIZE).tap do |buf|
               buf = buf + debris
-              lines = buf.split("\n")
-              lines.reverse.each do |line|
+              debris, *lines = buf.each_line.to_a
+              lines.reverse_each do |line|
                 yield(line)
               end
-              debris = lines.count > 0 ? lines[0] : ''
             end
             pos += BUFFER_SIZE
           end
@@ -139,8 +138,7 @@ module Gitlab
           last = (max > BUFFER_SIZE) ? (max % BUFFER_SIZE) : max
           stream.read(last).tap do |buf|
             buf = buf + debris
-            lines = buf.split("\n")
-            lines.reverse.each do |line|
+            buf.each_line.reverse_each do |line|
               yield(line)
             end
           end
diff --git a/spec/lib/gitlab/ci/trace/stream_spec.rb b/spec/lib/gitlab/ci/trace/stream_spec.rb
index d90ccf4f799..b4fdfd06daf 100644
--- a/spec/lib/gitlab/ci/trace/stream_spec.rb
+++ b/spec/lib/gitlab/ci/trace/stream_spec.rb
@@ -265,6 +265,17 @@ describe Gitlab::Ci::Trace::Stream do
       it { is_expected.to eq("98.29") }
     end
 
+    context 'when regex is multi-byte char' do
+      let(:data) { 'ゴッドファット\n' }
+      let(:regex) { 'ゴッドファット' }
+
+      before do
+        stub_const('Gitlab::Ci::Trace::Stream::BUFFER_SIZE', 5)
+      end
+
+      it { is_expected.to be_nil }
+    end
+
     context 'when BUFFER_SIZE is equal to stream.size' do
       let(:data) { 'Coverage 1033 / 1051 LOC (98.29%) covered\n' }
       let(:regex) { '\(\d+.\d+\%\) covered' }

From a6f6056c62693f18d9a2da570578b2e19aa20afe Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 17 May 2017 15:05:18 +0900
Subject: [PATCH 07/17] Use force_encoding when regex contains UTF-8 char

---
 lib/gitlab/ci/trace/stream.rb           | 2 +-
 spec/lib/gitlab/ci/trace/stream_spec.rb | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 56d6855c3c6..233cc5c1c7a 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -74,7 +74,7 @@ module Gitlab
           match = ""
 
           reverse_line do |line|
-            matches = line.scan(regex)
+            matches = line.force_encoding(Encoding.default_external).scan(regex)
             next unless matches.is_a?(Array)
             next if matches.empty?
 
diff --git a/spec/lib/gitlab/ci/trace/stream_spec.rb b/spec/lib/gitlab/ci/trace/stream_spec.rb
index b4fdfd06daf..bbb3f9912a3 100644
--- a/spec/lib/gitlab/ci/trace/stream_spec.rb
+++ b/spec/lib/gitlab/ci/trace/stream_spec.rb
@@ -266,14 +266,14 @@ describe Gitlab::Ci::Trace::Stream do
     end
 
     context 'when regex is multi-byte char' do
-      let(:data) { 'ゴッドファット\n' }
-      let(:regex) { 'ゴッドファット' }
+      let(:data) { '95.0 ゴッドファット\n' }
+      let(:regex) { '\d+\.\d+ ゴッドファット' }
 
       before do
         stub_const('Gitlab::Ci::Trace::Stream::BUFFER_SIZE', 5)
       end
 
-      it { is_expected.to be_nil }
+      it { is_expected.to eq('95.0') }
     end
 
     context 'when BUFFER_SIZE is equal to stream.size' do

From 318b46407239f35cd11d35b21271fa743d435dad Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 17 May 2017 17:53:31 +0900
Subject: [PATCH 08/17] Use force_encoding(regex.encoding)

---
 lib/gitlab/ci/trace/stream.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 233cc5c1c7a..3b4728951c4 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -74,7 +74,7 @@ module Gitlab
           match = ""
 
           reverse_line do |line|
-            matches = line.force_encoding(Encoding.default_external).scan(regex)
+            matches = line.force_encoding(regex.encoding).scan(regex)
             next unless matches.is_a?(Array)
             next if matches.empty?
 
@@ -86,7 +86,7 @@ module Gitlab
           nil
         rescue
           # if bad regex or something goes wrong we dont want to interrupt transition
-          # so we just silentrly ignore error for now
+          # so we just silently ignore error for now
         end
 
         private

From dddfa28eec6a55f8548e848d41b4fa3749a7d4d7 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 17 May 2017 18:18:16 +0900
Subject: [PATCH 09/17] Refer reverse_line from read_last_lines

---
 lib/gitlab/ci/trace/stream.rb | 29 +++++++----------------------
 1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 3b4728951c4..3d32fae6525 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -91,29 +91,14 @@ module Gitlab
 
         private
 
-        def read_last_lines(last_lines)
-          chunks = []
-          pos = lines = 0
-          max = stream.size
-
-          # We want an extra line to make sure fist line has full contents
-          while lines <= last_lines && pos < max
-            pos += BUFFER_SIZE
-
-            buf =
-              if pos <= max
-                stream.seek(-pos, IO::SEEK_END)
-                stream.read(BUFFER_SIZE)
-              else # Reached the head, read only left
-                stream.seek(0)
-                stream.read(BUFFER_SIZE - (pos - max))
-              end
-
-            lines += buf.count("\n")
-            chunks.unshift(buf)
+        def read_last_lines(limit)
+          result = ''
+          reverse_line do |line|
+            result = line + result
+            limit -= 1
+            return result if limit <= 0
           end
-
-          chunks.join.lines.last(last_lines).join
+          result
         end
 
         def reverse_line

From 6be609dd6418f1688d027f21cfe6fdb167375bc0 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 17 May 2017 18:26:38 +0900
Subject: [PATCH 10/17] much better

---
 lib/gitlab/ci/trace/stream.rb | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 3d32fae6525..5777332b251 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -92,13 +92,7 @@ module Gitlab
         private
 
         def read_last_lines(limit)
-          result = ''
-          reverse_line do |line|
-            result = line + result
-            limit -= 1
-            return result if limit <= 0
-          end
-          result
+          to_enum(:reverse_line).first(limit).reverse.join
         end
 
         def reverse_line

From 8c1b07e0cc3e461939cae0a9566cbab172360cdf Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 17 May 2017 20:21:13 +0900
Subject: [PATCH 11/17] Optimize reverse_line

---
 lib/gitlab/ci/trace/stream.rb | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 5777332b251..e8c34f3da05 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -96,30 +96,31 @@ module Gitlab
         end
 
         def reverse_line
-          pos = BUFFER_SIZE
+          pos = 0
           max = stream.size
           debris = ''
 
-          while pos < max
+          while (read_size = calc_read_size(pos, max)) > 0
+            pos += read_size
             stream.seek(-pos, IO::SEEK_END)
-            stream.read(BUFFER_SIZE).tap do |buf|
+            stream.read(read_size).tap do |buf|
               buf = buf + debris
               debris, *lines = buf.each_line.to_a
               lines.reverse_each do |line|
                 yield(line)
               end
             end
-            pos += BUFFER_SIZE
           end
 
-          # Reached the head, read only left
-          stream.seek(0)
-          last = (max > BUFFER_SIZE) ? (max % BUFFER_SIZE) : max
-          stream.read(last).tap do |buf|
-            buf = buf + debris
-            buf.each_line.reverse_each do |line|
-              yield(line)
-            end
+          yield(debris) if debris != ''
+        end
+
+        def calc_read_size(pos, max)
+          if pos > max
+            BUFFER_SIZE + (pos - max)
+          else
+            remain = max - pos
+            (remain > BUFFER_SIZE) ? BUFFER_SIZE : remain
           end
         end
       end

From fdcd2f192dd37ac2a2ea5b73926122009fbbe0aa Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 17 May 2017 20:39:47 +0900
Subject: [PATCH 12/17] Improve calc_read_size

---
 lib/gitlab/ci/trace/stream.rb | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index e8c34f3da05..39826846be0 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -116,12 +116,8 @@ module Gitlab
         end
 
         def calc_read_size(pos, max)
-          if pos > max
-            BUFFER_SIZE + (pos - max)
-          else
-            remain = max - pos
-            (remain > BUFFER_SIZE) ? BUFFER_SIZE : remain
-          end
+          remain = max - pos
+          (remain > BUFFER_SIZE) ? BUFFER_SIZE : remain
         end
       end
     end

From 72b0af2c4cefea51c521d3606a0a3307aee41348 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Thu, 18 May 2017 01:44:15 +0900
Subject: [PATCH 13/17] Avoid tap. Use unless&empty.

---
 lib/gitlab/ci/trace/stream.rb | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 39826846be0..d64c43df1d5 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -103,16 +103,14 @@ module Gitlab
           while (read_size = calc_read_size(pos, max)) > 0
             pos += read_size
             stream.seek(-pos, IO::SEEK_END)
-            stream.read(read_size).tap do |buf|
-              buf = buf + debris
-              debris, *lines = buf.each_line.to_a
-              lines.reverse_each do |line|
-                yield(line)
-              end
+            buf = stream.read(read_size) + debris
+            debris, *lines = buf.each_line.to_a
+            lines.reverse_each do |line|
+              yield(line)
             end
           end
 
-          yield(debris) if debris != ''
+          yield(debris) unless debris.empty?
         end
 
         def calc_read_size(pos, max)

From 22f1d2a1c46ce9eb2835611c4eac6948bd983488 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Thu, 18 May 2017 01:59:04 +0900
Subject: [PATCH 14/17] Append gurad clause. remove unless debris.empty

---
 lib/gitlab/ci/trace/stream.rb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index d64c43df1d5..c2abe37f003 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -96,6 +96,8 @@ module Gitlab
         end
 
         def reverse_line
+          return if stream.size <= 0
+
           pos = 0
           max = stream.size
           debris = ''
@@ -110,7 +112,7 @@ module Gitlab
             end
           end
 
-          yield(debris) unless debris.empty?
+          yield(debris)
         end
 
         def calc_read_size(pos, max)

From a16387486ae6db94b1aa49310cfc67642b68f23c Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Mon, 22 May 2017 15:17:08 +0900
Subject: [PATCH 15/17] put force_encoding in def reverse_line

---
 lib/gitlab/ci/trace/stream.rb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index c2abe37f003..45b32e4a7f2 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -74,7 +74,7 @@ module Gitlab
           match = ""
 
           reverse_line do |line|
-            matches = line.force_encoding(regex.encoding).scan(regex)
+            matches = line.scan(regex)
             next unless matches.is_a?(Array)
             next if matches.empty?
 
@@ -108,11 +108,11 @@ module Gitlab
             buf = stream.read(read_size) + debris
             debris, *lines = buf.each_line.to_a
             lines.reverse_each do |line|
-              yield(line)
+              yield(line.force_encoding('UTF-8'))
             end
           end
 
-          yield(debris)
+          yield(debris.force_encoding('UTF-8'))
         end
 
         def calc_read_size(pos, max)

From cf4ab10d71ea03c83fad22abf70dac21bbf73e72 Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Wed, 24 May 2017 20:20:20 +0900
Subject: [PATCH 16/17] Adopt ayufan script

---
 lib/gitlab/ci/trace/stream.rb | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index 45b32e4a7f2..c5a1ddfe691 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -96,28 +96,29 @@ module Gitlab
         end
 
         def reverse_line
-          return if stream.size <= 0
-
-          pos = 0
-          max = stream.size
+          stream.seek(0, IO::SEEK_END)
           debris = ''
 
-          while (read_size = calc_read_size(pos, max)) > 0
-            pos += read_size
-            stream.seek(-pos, IO::SEEK_END)
-            buf = stream.read(read_size) + debris
+          while !(buf = read_backward(BUFFER_SIZE)).empty?
+            buf += debris
             debris, *lines = buf.each_line.to_a
             lines.reverse_each do |line|
               yield(line.force_encoding('UTF-8'))
             end
           end
 
-          yield(debris.force_encoding('UTF-8'))
+          yield(debris.force_encoding('UTF-8')) if !(debris).empty?
         end
 
-        def calc_read_size(pos, max)
-          remain = max - pos
-          (remain > BUFFER_SIZE) ? BUFFER_SIZE : remain
+        def read_backward(length)
+          cur_offset = stream.tell
+          start = cur_offset - length
+          start = 0 if start < 0
+
+          stream.seek(start, IO::SEEK_SET)
+          stream.read(cur_offset - start).tap do
+            stream.seek(start, IO::SEEK_SET)
+          end
         end
       end
     end

From f9c9daac780666dbd2ce4ad6270c66e1ee32545a Mon Sep 17 00:00:00 2001
From: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date: Thu, 25 May 2017 01:35:40 +0900
Subject: [PATCH 17/17] Resolve static analysys. Use until instead of negative
 while

---
 lib/gitlab/ci/trace/stream.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/gitlab/ci/trace/stream.rb b/lib/gitlab/ci/trace/stream.rb
index c5a1ddfe691..c4c0623df6c 100644
--- a/lib/gitlab/ci/trace/stream.rb
+++ b/lib/gitlab/ci/trace/stream.rb
@@ -99,7 +99,7 @@ module Gitlab
           stream.seek(0, IO::SEEK_END)
           debris = ''
 
-          while !(buf = read_backward(BUFFER_SIZE)).empty?
+          until (buf = read_backward(BUFFER_SIZE)).empty?
             buf += debris
             debris, *lines = buf.each_line.to_a
             lines.reverse_each do |line|
@@ -107,7 +107,7 @@ module Gitlab
             end
           end
 
-          yield(debris.force_encoding('UTF-8')) if !(debris).empty?
+          yield(debris.force_encoding('UTF-8')) unless debris.empty?
         end
 
         def read_backward(length)