Continue pulling release_name and git_revision out of SearchPath

diff --git a/pinch.py b/pinch.py
index 5e6aab9f6dcaab63bcbd936069b51654a7cd6182..1b11709901e79825fe98a3e9bb10699be374db9d 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -25,6 +25,7 @@ from typing import (
     Mapping,
     NamedTuple,
     NewType,
+    Optional,
     Tuple,
     Type,
     Union,
@@ -132,19 +133,19 @@ class TarrableSearchPath(SearchPath, ABC):  # pylint: disable=abstract-method
     forwarded_url: str
     git_ref: str
     git_repo: str
-    old_git_revision: str
     table: Dict[str, ChannelTableEntry]
 
 
 class GitSearchPath(TarrableSearchPath):
     def pin(self, v: Verification) -> GitPin:
+        old_revision = (
+            self.git_revision if hasattr(self, 'git_revision') else None)
         if hasattr(self, 'git_revision'):
-            self.old_git_revision = self.git_revision
             del self.git_revision
 
-        git_fetch(v, self)
-        return GitPin(release_name=git_revision_name(v, self),
-                      git_revision=self.git_revision)
+        new_revision = git_fetch(v, self, None, old_revision)
+        return GitPin(release_name=git_revision_name(v, self, new_revision),
+                      git_revision=new_revision)
 
     def fetch(self, v: Verification, section: str,
               conf: configparser.SectionProxy) -> str:
@@ -156,20 +157,21 @@ class GitSearchPath(TarrableSearchPath):
             release_name=conf['release_name'],
             git_revision=conf['git_revision'])
 
-        ensure_git_rev_available(v, self, the_pin)
+        ensure_git_rev_available(v, self, the_pin, None)
         return git_get_tarball(v, self, the_pin)
 
 
 class ChannelSearchPath(TarrableSearchPath):
     def pin(self, v: Verification) -> ChannelPin:
+        old_revision = (
+            self.git_revision if hasattr(self, 'git_revision') else None)
         if hasattr(self, 'git_revision'):
-            self.old_git_revision = self.git_revision
             del self.git_revision
 
         fetch(v, self)
         new_gitpin = parse_channel(v, self)
         fetch_resources(v, self, new_gitpin)
-        ensure_git_rev_available(v, self, new_gitpin)
+        ensure_git_rev_available(v, self, new_gitpin, old_revision)
         check_channel_contents(v, self)
         return ChannelPin(
             release_name=self.release_name,
@@ -342,7 +344,11 @@ def tarball_cache_file(channel: TarrableSearchPath) -> str:
          channel.release_name))
 
 
-def verify_git_ancestry(v: Verification, channel: TarrableSearchPath) -> None:
+def verify_git_ancestry(
+        v: Verification,
+        channel: TarrableSearchPath,
+        new_revision: str,
+        old_revision: Optional[str]) -> None:
     cachedir = git_cachedir(channel.git_repo)
     v.status('Verifying rev is an ancestor of ref')
     process = subprocess.run(['git',
@@ -350,25 +356,29 @@ def verify_git_ancestry(v: Verification, channel: TarrableSearchPath) -> None:
                               cachedir,
                               'merge-base',
                               '--is-ancestor',
-                              channel.git_revision,
+                              new_revision,
                               channel.git_ref])
     v.result(process.returncode == 0)
 
-    if hasattr(channel, 'old_git_revision'):
+    if old_revision is not None:
         v.status(
             'Verifying rev is an ancestor of previous rev %s' %
-            channel.old_git_revision)
+            old_revision)
         process = subprocess.run(['git',
                                   '-C',
                                   cachedir,
                                   'merge-base',
                                   '--is-ancestor',
-                                  channel.old_git_revision,
-                                  channel.git_revision])
+                                  old_revision,
+                                  new_revision])
         v.result(process.returncode == 0)
 
 
-def git_fetch(v: Verification, channel: TarrableSearchPath) -> None:
+def git_fetch(
+        v: Verification,
+        channel: TarrableSearchPath,
+        desired_revision: Optional[str],
+        old_revision: Optional[str]) -> str:
     # It would be nice if we could share the nix git cache, but as of the time
     # of writing it is transitioning from gitv2 (deprecated) to gitv3 (not ready
     # yet), and trying to straddle them both is too far into nix implementation
@@ -394,26 +404,29 @@ def git_fetch(v: Verification, channel: TarrableSearchPath) -> None:
                                          channel.git_ref)])
     v.result(process.returncode == 0)
 
-    if hasattr(channel, 'git_revision'):
+    if desired_revision is not None:
         v.status('Verifying that fetch retrieved this rev')
         process = subprocess.run(
-            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_revision])
+            ['git', '-C', cachedir, 'cat-file', '-e', desired_revision])
         v.result(process.returncode == 0)
-    else:
-        channel.git_revision = open(
-            os.path.join(
-                cachedir,
-                'refs',
-                'heads',
-                channel.git_ref)).read(999).strip()
 
-    verify_git_ancestry(v, channel)
+    new_revision = open(
+        os.path.join(
+            cachedir,
+            'refs',
+            'heads',
+            channel.git_ref)).read(999).strip()
+
+    verify_git_ancestry(v, channel, new_revision, old_revision)
+
+    return new_revision
 
 
 def ensure_git_rev_available(
         v: Verification,
         channel: TarrableSearchPath,
-        pin: GitPin) -> None:
+        pin: GitPin,
+        old_revision: Optional[str]) -> None:
     cachedir = git_cachedir(channel.git_repo)
     if os.path.exists(cachedir):
         v.status('Checking if we already have this rev:')
@@ -425,9 +438,9 @@ def ensure_git_rev_available(
             v.status('no')
         v.result(process.returncode == 0 or process.returncode == 1)
         if process.returncode == 0:
-            verify_git_ancestry(v, channel)
+            verify_git_ancestry(v, channel, pin.git_revision, old_revision)
             return
-    git_fetch(v, channel)
+    git_fetch(v, channel, pin.git_revision, old_revision)
 
 
 def compare_tarball_and_git(
@@ -576,7 +589,10 @@ def check_channel_contents(
     v.ok()
 
 
-def git_revision_name(v: Verification, channel: TarrableSearchPath) -> str:
+def git_revision_name(
+        v: Verification,
+        channel: TarrableSearchPath,
+        git_revision: str) -> str:
     v.status('Getting commit date')
     process = subprocess.run(['git',
                               '-C',
@@ -586,7 +602,7 @@ def git_revision_name(v: Verification, channel: TarrableSearchPath) -> str:
                               '--format=%ct-%h',
                               '--abbrev=11',
                               '--no-show-signature',
-                              channel.git_revision],
+                              git_revision],
                              stdout=subprocess.PIPE)
     v.result(process.returncode == 0 and process.stdout != b'')
     return '%s-%s' % (os.path.basename(channel.git_repo),