From a4d8caf302d189caea20c84b37d556f2f503d646 Mon Sep 17 00:00:00 2001
From: Craig Tracey <craigtracey@gmail.com>
Date: Fri, 9 Oct 2015 22:55:52 -0400
Subject: [PATCH] Add parallel builds

This change runs builds in parallel. By default all projects run
simultaneously unless --synchronous is specified. This should speed
up build times dramatically.
---
 giftwrap/build_spec.py        |  3 ++-
 giftwrap/builders/__init__.py | 14 +++++++++++++-
 giftwrap/settings.py          |  4 +++-
 giftwrap/shell.py             |  4 +++-
 4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/giftwrap/build_spec.py b/giftwrap/build_spec.py
index c0a7e2b..dbcb555 100644
--- a/giftwrap/build_spec.py
+++ b/giftwrap/build_spec.py
@@ -22,7 +22,7 @@ from giftwrap.settings import Settings
 
 class BuildSpec(object):
 
-    def __init__(self, manifest, version, build_type=None):
+    def __init__(self, manifest, version, build_type=None, parallel=True):
         self._manifest = yaml.load(manifest)
         self.version = version
         self.build_type = build_type
@@ -31,6 +31,7 @@ class BuildSpec(object):
             manifest_settings['version'] = version
         if build_type:
             manifest_settings['build_type'] = build_type
+        manifest_settings['parallel_build'] = parallel
         self.settings = Settings.factory(manifest_settings)
         self.projects = self._render_projects()
 
diff --git a/giftwrap/builders/__init__.py b/giftwrap/builders/__init__.py
index 666507a..fede4c1 100644
--- a/giftwrap/builders/__init__.py
+++ b/giftwrap/builders/__init__.py
@@ -16,6 +16,7 @@
 
 import logging
 import os
+import threading
 
 from giftwrap.gerrit import GerritReview
 
@@ -84,8 +85,19 @@ class Builder(object):
         self._temp_src_dir = os.path.join(self._temp_dir, 'src')
         LOG.debug("Temporary working directory: %s", self._temp_dir)
 
+        threads = []
         for project in spec.projects:
-            self._build_project(project)
+            if spec.settings.parallel_build:
+                t = threading.Thread(target=self._build_project,
+                                     args=(project,))
+                threads.append(t)
+                t.start()
+            else:
+                self._build_project(project)
+
+        if spec.settings.parallel_build:
+            for thread in threads:
+                thread.join()
 
         self._finalize_build()
 
diff --git a/giftwrap/settings.py b/giftwrap/settings.py
index 6175b2c..d6962e1 100644
--- a/giftwrap/settings.py
+++ b/giftwrap/settings.py
@@ -30,7 +30,8 @@ class Settings(object):
     def __init__(self, build_type=DEFAULT_BUILD_TYPE,
                  package_name_format=None, version=None,
                  base_path=None, install_path=None, gerrit_dependencies=True,
-                 force_overwrite=False, output_dir=None, include_config=True):
+                 force_overwrite=False, output_dir=None, include_config=True,
+                 parallel_build=True):
         if not version:
             raise Exception("'version' is a required settings")
         self.build_type = build_type
@@ -42,6 +43,7 @@ class Settings(object):
         self.force_overwrite = force_overwrite
         self._output_dir = output_dir
         self.include_config = include_config
+        self.parallel_build = parallel_build
 
     @property
     def package_name_format(self):
diff --git a/giftwrap/shell.py b/giftwrap/shell.py
index a461fed..f46ce1c 100644
--- a/giftwrap/shell.py
+++ b/giftwrap/shell.py
@@ -46,7 +46,7 @@ def build(args):
         with open(args.manifest, 'r') as fh:
             manifest = fh.read()
 
-        buildspec = BuildSpec(manifest, args.version, args.type)
+        buildspec = BuildSpec(manifest, args.version, args.type, args.parallel)
         builder = BuilderFactory.create_builder(args.type, buildspec)
 
         def _signal_handler(*args):
@@ -80,6 +80,8 @@ def main():
     build_subcmd.add_argument('-v', '--version')
     build_subcmd.add_argument('-t', '--type', choices=('docker', 'package'),
                               required=True)
+    build_subcmd.add_argument('-s', '--synchronous', dest='parallel',
+                              action='store_false')
     build_subcmd.set_defaults(func=build)
 
     args = parser.parse_args()