Make gclient_scm.py use cache_dir

gclient_scm.py

Index: gclient_scm.py
diff --git a/gclient_scm.py b/gclient_scm.py
index 0389f466203b86413e0253ab9095d4cd422fe8ad..238122fce653903fd38b9ab28d93d1030dc0fed7 100644
--- a/gclient_scm.py
+++ b/gclient_scm.py
@@ -4,14 +4,12 @@
 
 """Gclient-specific SCM-specific operations."""
 
-import collections
 import logging
 import os
 import posixpath
 import re
 import sys
 import tempfile
-import threading
 import traceback
 import urlparse
 
@@ -148,9 +146,6 @@ class GitWrapper(SCMWrapper):
   remote = 'origin'
 
   cache_dir = None
-  # If a given cache is used in a solution more than once, prevent multiple
-  # threads from updating it simultaneously.
-  cache_locks = collections.defaultdict(threading.Lock)
 
   def __init__(self, url=None, root_dir=None, relpath=None):
     """Removes 'git+' fake prefix from git URL."""
@@ -352,10 +347,6 @@ class GitWrapper(SCMWrapper):
       self._FetchAndReset(revision, file_list, options)
       return_early = True
 
-    # Need to do this in the normal path as well as in the post-remote-switch
-    # path.
-    self._PossiblySwitchCache(url, options)
-
     if return_early:
       return self._Capture(['rev-parse', '--verify', 'HEAD'])
 
@@ -681,54 +672,6 @@ class GitWrapper(SCMWrapper):
     base_url = self.url
     return base_url[:base_url.rfind('/')] + url
 
-  @staticmethod
-  def _NormalizeGitURL(url):
-    '''Takes a git url, strips the scheme, and ensures it ends with '.git'.'''
-    idx = url.find('://')
-    if idx != -1:
-      url = url[idx+3:]
-    if not url.endswith('.git'):
-      url += '.git'
-    return url
-
-  def _PossiblySwitchCache(self, url, options):
-    """Handles switching a repo from with-cache to direct, or vice versa.
-
-    When we go from direct to with-cache, the remote url changes from the
-    'real' url to the local file url (in cache_dir). Therefore, this function
-    assumes that |url| points to the correctly-switched-over local file url, if
-    we're in cache_mode.
-
-    When we go from with-cache to direct, assume that the normal url-switching
-    code already flipped the remote over, and we just need to repack and break
-    the dependency to the cache.
-    """
-
-    altfile = os.path.join(
-        self.checkout_path, '.git', 'objects', 'info', 'alternates')
-    if self.cache_dir:
-      if not os.path.exists(altfile):
-        try:
-          with open(altfile, 'w') as f:
-            f.write(os.path.join(url, 'objects'))
-          # pylint: disable=C0301
-          # This dance is necessary according to emperical evidence, also at:
-          # http://lists-archives.com/git/713652-retrospectively-add-alternates-to-a-repository.html
-          self._Run(['repack', '-ad'], options)
-          self._Run(['repack', '-adl'], options)
-        except Exception:
-          # If something goes wrong, try to remove the altfile so we'll go down
-          # this path again next time.
-          try:
-            os.remove(altfile)
-          except OSError as e:
-            print >> sys.stderr, "FAILED: os.remove('%s') -> %s" % (altfile, e)
-          raise
-    else:
-      if os.path.exists(altfile):
-        self._Run(['repack', '-a'], options)
-        os.remove(altfile)
-
   def _CreateOrUpdateCache(self, url, options):
     """Make a new git mirror or update existing mirror for |url|, and return the
     mirror URI to clone from.
@@ -737,60 +680,12 @@ class GitWrapper(SCMWrapper):
     """
     if not self.cache_dir:
       return url
-
-    # Replace - with -- to avoid ambiguity. / with - to flatten folder structure
-    folder = os.path.join(
-      self.cache_dir,
-      self._NormalizeGitURL(url).replace('-', '--').replace('/', '-'))
-    altfile = os.path.join(folder, 'objects', 'info', 'alternates')
-
-    # If we're bringing an old cache up to date or cloning a new cache, and the
-    # existing repo is currently a direct clone, use its objects to help out
-    # the fetch here.
-    checkout_objects = os.path.join(self.checkout_path, '.git', 'objects')
-    checkout_altfile = os.path.join(checkout_objects, 'info', 'alternates')
-    use_reference = (
-        os.path.exists(checkout_objects) and
-        not os.path.exists(checkout_altfile))
-
     v = ['-v'] if options.verbose else []
-    filter_fn = lambda l: '[up to date]' not in l
-    with self.cache_locks[folder]:
-      gclient_utils.safe_makedirs(self.cache_dir)
-      if not os.path.exists(os.path.join(folder, 'config')):
-        gclient_utils.rmtree(folder)
-        cmd = ['clone'] + v + ['-c', 'core.deltaBaseCacheLimit=2g',
-                               '--progress', '--bare']
-
-        if use_reference:
-          cmd += ['--reference', os.path.abspath(self.checkout_path)]
-
-        self._Run(cmd + [url, folder],
-                  options, filter_fn=filter_fn, cwd=self.cache_dir, retry=True)
-      else:
-        # For now, assert that host/path/to/repo.git is identical. We may want
-        # to relax this restriction in the future to allow for smarter cache
-        # repo update schemes (such as pulling the same repo, but from a
-        # different host).
-        existing_url = self._Capture(['config', 'remote.%s.url' % self.remote],
-                                     cwd=folder)
-        assert self._NormalizeGitURL(existing_url) == self._NormalizeGitURL(url)
-
-        if use_reference:
-          with open(altfile, 'w') as f:
-            f.write(os.path.abspath(checkout_objects))
-
-        # Would normally use `git remote update`, but it doesn't support
-        # --progress, so use fetch instead.
-        self._Run(['fetch'] + v + ['--multiple', '--progress', '--all'],
-                  options, filter_fn=filter_fn, cwd=folder, retry=True)
-
-      # If the clone has an object dependency on the existing repo, break it
-      # with repack and remove the linkage.
-      if os.path.exists(altfile):
-        self._Run(['repack', '-a'], options, cwd=folder)
-        os.remove(altfile)
-    return folder
+    self._Run(['cache', 'populate'] + v +
+              ['--shallow', '--cache-dir', self.cache_dir, url],
+              options, cwd=self._root_dir, retry=True)
+    return self._Run(['cache', 'exists', '--cache-dir', self.cache_dir, url],
+                     options).strip()
 
   def _Clone(self, revision, url, options):
     """Clone a git repository from the given URL.
@@ -1044,7 +939,7 @@ class GitWrapper(SCMWrapper):
     stdout = kwargs.get('stdout', sys.stdout)
     stdout.write('\n________ running \'git %s\' in \'%s\'\n' % (
                  ' '.join(args), kwargs['cwd']))
-    gclient_utils.CheckCallAndFilter(['git'] + args, **kwargs)
+    return gclient_utils.CheckCallAndFilter(['git'] + args, **kwargs)
 
 
 class SVNWrapper(SCMWrapper):