Make git-freeze bail out if the user has too much untracked data.

R=iannucci@chromium.org
BUG=376099

Review-Url: https://codereview.chromium.org/2052113002

git_common.py

@@ -32,8 +32,10 @@ import threading
 
 import subprocess2
 
-ROOT = os.path.abspath(os.path.dirname(__file__))
+from StringIO import StringIO
+
 
+ROOT = os.path.abspath(os.path.dirname(__file__))
 IS_WIN = sys.platform == 'win32'
 GIT_EXE = ROOT+'\\git.bat' if IS_WIN else 'git'
 TEST_MODE = False
@@ -392,6 +394,36 @@ def diff(oldrev, newrev, *args):
 
 def freeze():
   took_action = False
+  key = 'depot-tools.freeze-size-limit'
+  MB = 2**20
+  limit_mb = get_config_int(key, 100)
+  untracked_bytes = 0
+
+  for f, s in status():
+    if is_unmerged(s):
+      die("Cannot freeze unmerged changes!")
+    if limit_mb > 0:
+      if s.lstat == '?':
+        untracked_bytes += os.stat(f).st_size
+      if untracked_bytes > limit_mb * MB:
+        die("""\
+          You appear to have too much untracked+unignored data in your git
+          checkout: %.1f / %d MB.
+
+          Run `git status` to see what it is.
+
+          In addition to making many git commands slower, this will prevent
+          depot_tools from freezing your in-progress changes.
+
+          You should add untracked data that you want to ignore to your repo's
+            .git/info/excludes
+          file. See `git help ignore` for the format of this file.
+
+          If this data is indended as part of your commit, you may adjust the
+          freeze limit by running:
+            git config %s <new_limit>
+          Where <new_limit> is an integer threshold in megabytes.""",
+          untracked_bytes / (MB * 1.0), limit_mb, key)
 
   try:
     run('commit', '--no-verify', '-m', FREEZE + '.indexed')
@@ -502,6 +534,13 @@ def is_dormant(branch):
   return branch_config(branch, 'dormant', 'false') != 'false'
 
 
+def is_unmerged(stat_value):
+  return (
+      'U' in (stat_value.lstat, stat_value.rstat) or
+      ((stat_value.lstat == stat_value.rstat) and stat_value.lstat in 'AD')
+  )
+
+
 def manual_merge_base(branch, base, parent):
   set_branch_config(branch, 'base', base)
   set_branch_config(branch, 'base-upstream', parent)
@@ -711,6 +750,45 @@ def is_dirty_git_tree(cmd):
   return False
 
 
+def status():
+  """Returns a parsed version of git-status.
+
+  Returns a generator of (current_name, (lstat, rstat, src)) pairs where:
+    * current_name is the name of the file
+    * lstat is the left status code letter from git-status
+    * rstat is the left status code letter from git-status
+    * src is the current name of the file, or the original name of the file
+      if lstat == 'R'
+  """
+  stat_entry = collections.namedtuple('stat_entry', 'lstat rstat src')
+
+  def tokenizer(stream):
+    acc = StringIO()
+    c = None
+    while c != '':
+      c = stream.read(1)
+      if c in (None, '', '\0'):
+        if acc.len:
+          yield acc.getvalue()
+          acc = StringIO()
+      else:
+        acc.write(c)
+
+  def parser(tokens):
+    while True:
+      # Raises StopIteration if it runs out of tokens.
+      status_dest = next(tokens)
+      stat, dest = status_dest[:2], status_dest[3:]
+      lstat, rstat = stat
+      if lstat == 'R':
+        src = next(tokens)
+      else:
+        src = dest
+      yield (dest, stat_entry(lstat, rstat, src))
+
+  return parser(tokenizer(run_stream('status', '-z', bufsize=-1)))
+
+
 def squash_current_branch(header=None, merge_base=None):
   header = header or 'git squash commit.'
   merge_base = merge_base or get_or_create_merge_base(current_branch())

man/html/git-freeze.html

@@ -773,6 +773,8 @@ exactly the same working state later (by running <code>git thaw</code>).</p></di
 with <em>git add</em>, <em>git mv</em>, <em>git rm</em>, etc.). A commit with the message
 <code>FREEZE.unindexed</code> will contain all changes which were not in your index at the
 time you ran git freeze (freshly modified files, new files, etc.).</p></div>
+<div class="paragraph"><p>By default <code>git freeze</code> will only freeze up to 100MB of untracked files. See
+<em>CONFIGURATION VARIABLES</em> for more details.</p></div>
 </div>
 </div>
 <div class="sect1">
@@ -788,7 +790,7 @@ time you ran git freeze (freshly modified files, new files, etc.).</p></div>
 <span style="font-weight: bold; color: #ffffff">$ git freeze</span>
 <span style="font-weight: bold; color: #ffffff">$ git status --short</span>
 <span style="font-weight: bold; color: #ffffff">$ git log -n 2 --stat</span>
-<span style="color: #e7e71c">commit 648c29b68da0142bcad41872339f9732c6ec4470</span>
+<span style="color: #e7e71c">commit 07f208f5916bd8ee3affbf8d182c918a8dc1a699</span>
 Author: local &lt;local@chromium.org&gt;
 Date:   Thu Apr 10 08:54:56 2014 +0000
 
@@ -800,7 +802,7 @@ Date:   Thu Apr 10 08:54:56 2014 +0000
  unstaged_deleted_file            | 1 <span style="color: #e42e16">-</span>
  4 files changed, 2 insertions(+), 1 deletion(-)
 
-<span style="color: #e7e71c">commit a4e49c2896814f52feec3fc06ef0454962ee6b8c</span>
+<span style="color: #e7e71c">commit 9f803ff1f05dd0c77d31b8958992520e37ed6278</span>
 Author: local &lt;local@chromium.org&gt;
 Date:   Thu Apr 10 08:54:56 2014 +0000
 
@@ -822,6 +824,17 @@ Date:   Thu Apr 10 08:54:56 2014 +0000
 </div>
 </div>
 <div class="sect1">
+<h2 id="_configuration_variables">CONFIGURATION VARIABLES</h2>
+<div class="sectionbody">
+<div class="sect2">
+<h3 id="_depot_tools_freeze_size_limit">depot-tools.freeze-size-limit</h3>
+<div class="paragraph"><p>This sets the size limit as an integer number of megabytes of untracked files
+that git-freeze will be willing to put in suspended animation. A 0 or negative
+limit disables the size-limit check entirely. <strong>100</strong> by default.</p></div>
+</div>
+</div>
+</div>
+<div class="sect1">
 <h2 id="_see_also">SEE ALSO</h2>
 <div class="sectionbody">
 <div class="paragraph"><p><a href="git-thaw.html">git-thaw(1)</a></p></div>
@@ -839,7 +852,7 @@ from <a href="https://chromium.googlesource.com/chromium/tools/depot_tools.git">
 <div id="footnotes"><hr /></div>
 <div id="footer">
 <div id="footer-text">
-Last updated 2014-04-10 14:23:11 PDT
+Last updated 2014-06-04 16:12:59 PDT
 </div>
 </div>
 </body>

man/man1/git-freeze.1

@@ -2,12 +2,12 @@
 .\"     Title: git-freeze
 .\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
 .\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
-.\"      Date: 04/10/2014
+.\"      Date: 06/04/2014
 .\"    Manual: Chromium depot_tools Manual
-.\"    Source: depot_tools 68b1017
+.\"    Source: depot_tools d39bbb5
 .\"  Language: English
 .\"
-.TH "GIT\-FREEZE" "1" "04/10/2014" "depot_tools 68b1017" "Chromium depot_tools Manual"
+.TH "GIT\-FREEZE" "1" "06/04/2014" "depot_tools d39bbb5" "Chromium depot_tools Manual"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -40,6 +40,8 @@ git-freeze \- Freeze all changes on a branch (indexed and unindexed)\&.
 git freeze works a lot like git stash, in that it stores the current changes in your working copy and index \fIsomewhere\fR\&. Unlike git stash, git freeze stores those changes on your current branch\&. This effectively allows you to \fIpause\fR development of a branch, work on something else, and then come back to exactly the same working state later (by running git thaw)\&.
 .sp
 git freeze will make up to 2 commits on your branch\&. A commit with the message FREEZE\&.indexed will contain all changes which you\(cqve added to your index (like with \fIgit add\fR, \fIgit mv\fR, \fIgit rm\fR, etc\&.)\&. A commit with the message FREEZE\&.unindexed will contain all changes which were not in your index at the time you ran git freeze (freshly modified files, new files, etc\&.)\&.
+.sp
+By default git freeze will only freeze up to 100MB of untracked files\&. See \fICONFIGURATION VARIABLES\fR for more details\&.
 .SH "EXAMPLE"
 .sp
 
@@ -58,7 +60,7 @@ D  deleted_file
 \fB$ git freeze\fR
 \fB$ git status \-\-short\fR
 \fB$ git log \-n 2 \-\-stat\fR
-commit 85b90eda860a6f62d95efdb29a09ebe2bace018d
+commit 13e157e1f666206fca297c48bec82f3f16ae3c2f
 Author: local <local@chromium\&.org>
 Date:   Thu Apr 10 08:54:56 2014 +0000
 
@@ -70,7 +72,7 @@ Date:   Thu Apr 10 08:54:56 2014 +0000
  unstaged_deleted_file            | 1 \-
  4 files changed, 2 insertions(+), 1 deletion(\-)
 
-commit 4d4db1b3bfbb42b0c9c87326bd522cc9d6946911
+commit 30791edff23b9a8fecc5f863da134e820a4c9f1a
 Author: local <local@chromium\&.org>
 Date:   Thu Apr 10 08:54:56 2014 +0000
 
@@ -93,6 +95,10 @@ D  deleted_file
 .RE
 .\}
 .sp
+.SH "CONFIGURATION VARIABLES"
+.SS "depot\-tools\&.freeze\-size\-limit"
+.sp
+This sets the size limit as an integer number of megabytes of untracked files that git\-freeze will be willing to put in suspended animation\&. A 0 or negative limit disables the size\-limit check entirely\&. \fB100\fR by default\&.
 .SH "SEE ALSO"
 .sp
 \fBgit-thaw\fR(1)

man/src/git-freeze.txt

@@ -26,10 +26,25 @@ with 'git add', 'git mv', 'git rm', etc.). A commit with the message
 `FREEZE.unindexed` will contain all changes which were not in your index at the
 time you ran git freeze (freshly modified files, new files, etc.).
 
+By default `git freeze` will only freeze up to 100MB of untracked files. See
+'CONFIGURATION VARIABLES' for more details.
+
+
 EXAMPLE
 -------
 demo:1[]
 
+
+CONFIGURATION VARIABLES
+-----------------------
+
+depot-tools.freeze-size-limit
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+This sets the size limit as an integer number of megabytes of untracked files
+that git-freeze will be willing to put in suspended animation. A 0 or negative
+limit disables the size-limit check entirely. *100* by default.
+
+
 SEE ALSO
 --------
 linkgit:git-thaw[1]

tests/git_common_test.py

@@ -731,6 +731,23 @@ class GitMutableStructuredTest(git_test_utils.GitRepoReadWriteTestBase,
     CAT DOG
     """)
 
+  def testStatus(self):
+    def inner():
+      dictified_status = lambda: {
+          k: dict(v._asdict())  # pylint: disable=W0212
+          for k, v in self.repo.run(self.gc.status)
+      }
+      self.repo.git('mv', 'file', 'cat')
+      with open('COOL', 'w') as f:
+        f.write('Super cool file!')
+      self.assertDictEqual(
+          dictified_status(),
+          {'cat':  {'lstat': 'R', 'rstat': ' ', 'src': 'file'},
+           'COOL': {'lstat': '?', 'rstat': '?', 'src': 'COOL'}}
+      )
+
+    self.repo.run(inner)
+
 
 class GitFreezeThaw(git_test_utils.GitRepoReadWriteTestBase):
   @classmethod
@@ -809,6 +826,52 @@ class GitFreezeThaw(git_test_utils.GitRepoReadWriteTestBase):
 
     self.repo.run(inner)
 
+  def testTooBig(self):
+    def inner():
+      self.repo.git('config', 'depot-tools.freeze-size-limit', '1')
+      with open('bigfile', 'w') as f:
+        chunk = 'NERDFACE' * 1024
+        for _ in xrange(128 * 2 + 1):  # Just over 2 mb
+          f.write(chunk)
+      _, err = self.repo.capture_stdio(self.gc.freeze)
+      self.assertIn('too much untracked+unignored', err)
+
+    self.repo.run(inner)
+
+  def testTooBigMultipleFiles(self):
+    def inner():
+      self.repo.git('config', 'depot-tools.freeze-size-limit', '1')
+      for i in xrange(3):
+        with open('file%d' % i, 'w') as f:
+          chunk = 'NERDFACE' * 1024
+          for _ in xrange(50):  # About 400k
+            f.write(chunk)
+      _, err = self.repo.capture_stdio(self.gc.freeze)
+      self.assertIn('too much untracked+unignored', err)
+
+    self.repo.run(inner)
+
+  def testMerge(self):
+    def inner():
+      self.repo.git('checkout', '-b', 'bad_merge_branch')
+      with open('bad_merge', 'w') as f:
+        f.write('bad_merge_left')
+      self.repo.git('add', 'bad_merge')
+      self.repo.git('commit', '-m', 'bad_merge')
+
+      self.repo.git('checkout', 'branch_D')
+      with open('bad_merge', 'w') as f:
+        f.write('bad_merge_right')
+      self.repo.git('add', 'bad_merge')
+      self.repo.git('commit', '-m', 'bad_merge_d')
+
+      self.repo.git('merge', 'bad_merge_branch')
+
+      _, err = self.repo.capture_stdio(self.gc.freeze)
+      self.assertIn('Cannot freeze unmerged changes', err)
+
+    self.repo.run(inner)
+
 
 class GitMakeWorkdir(git_test_utils.GitRepoReadOnlyTestBase, GitCommonTestBase):
   def setUp(self):