Fix hardlinking issue happening on linux.

Uses a temporary directory on the same filesystem than cache_dir if /tmp is
mapped on another file system, like tmpfs.

NOTRY=true
R=cmp@chromium.org
BUG=
TEST=


Review URL: https://chromiumcodereview.appspot.com/10538010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@140575 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 1 deletions

diff --git a/tools/isolate/run_test_from_archive.py b/tools/isolate/run_test_from_archive.py
index 847e5cf..220e24f 100755
--- a/tools/isolate/run_test_from_archive.py
+++ b/tools/isolate/run_test_from_archive.py
@@ -107,6 +107,14 @@ def rmtree(root):
     shutil.rmtree(root)
 
 
+def is_same_filesystem(path1, path2):
+  """Returns True if both paths are on the same filesystem.
+
+  This is required to enable the use of hardlinks.
+  """
+  return os.stat(path1).st_dev == os.stat(path2).st_dev
+
+
 def open_remote(file_or_url):
   """Reads a file or url."""
   if re.match(r'^https?://.+$', file_or_url):
@@ -266,7 +274,15 @@ def run_tha_test(manifest, cache_dir, remote, max_cache_size, min_free_space):
   directory and runs the executable.
   """
   cache = Cache(cache_dir, remote, max_cache_size, min_free_space)
-  outdir = tempfile.mkdtemp(prefix='run_tha_test')
+
+  base_temp_dir = None
+  if not is_same_filesystem(cache_dir, tempfile.gettempdir()):
+    # Do not use tempdir since it's a separate filesystem than cache_dir. It
+    # could be tmpfs for example. This would mean copying up to 100mb of data
+    # there, when a simple tree of hardlinks would do.
+    base_temp_dir = os.path.dirname(cache_dir)
+  outdir = tempfile.mkdtemp(prefix='run_tha_test', dir=base_temp_dir)
+
   try:
     for filepath, properties in manifest['files'].iteritems():
       infile = properties['sha-1']