Split ensure_git_rev_available out from git_fetch

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index 6ad2cdccbd991d596e7974f563d7844218461d96..0f8f00a611390cff8aaca8e20ff0d1361a4a4274 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -38,7 +38,6 @@ class Channel(types.SimpleNamespace):
     channel_html: bytes
     channel_url: str
     forwarded_url: str
     channel_html: bytes
     channel_url: str
     forwarded_url: str

-    git_cachedir: str

     git_ref: str
     git_repo: str
     git_revision: str
     git_ref: str
     git_repo: str
     git_revision: str


@@ -212,68 +211,20 @@ def fetch_resources(v: Verification, channel: Channel) -> None:
             channel.table['git-revision'].file).read(999) == channel.git_revision)
 
 
             channel.table['git-revision'].file).read(999) == channel.git_revision)
 
 

-def git_fetch(v: Verification, channel: Channel) -> None:
-    # 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
-    # details for my comfort.  So we re-implement here half of nix.fetchGit.
-    # :(
-
+def git_cachedir(git_repo: str) -> str:

     # TODO: Consider using pyxdg to find this path.
     # TODO: Consider using pyxdg to find this path.

-    channel.git_cachedir = os.path.expanduser(
+    return os.path.expanduser(

         '~/.cache/nix-pin-channel/git/%s' %
         digest_string(
         '~/.cache/nix-pin-channel/git/%s' %
         digest_string(

-            channel.git_repo.encode()))
-    if not os.path.exists(channel.git_cachedir):
-        v.status("Initializing git repo")
-        process = subprocess.run(
-            ['git', 'init', '--bare', channel.git_cachedir])
-        v.result(process.returncode == 0)
-
-    have_rev = False
-    if hasattr(channel, 'git_revision'):
-        v.status('Checking if we already have this rev:')
-        process = subprocess.run(
-            ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_revision])
-        if process.returncode == 0:
-            v.status('yes')
-        if process.returncode == 1:
-            v.status('no')
-        v.result(process.returncode == 0 or process.returncode == 1)
-        have_rev = process.returncode == 0
+            git_repo.encode()))

 
 

-    if not have_rev:
-        v.status(
-            'Fetching ref "%s" from %s' %
-            (channel.git_ref, channel.git_repo))
-        # We don't use --force here because we want to abort and freak out if forced
-        # updates are happening.
-        process = subprocess.run(['git',
-                                  '-C',
-                                  channel.git_cachedir,
-                                  'fetch',
-                                  channel.git_repo,
-                                  '%s:%s' % (channel.git_ref,
-                                             channel.git_ref)])
-        v.result(process.returncode == 0)
-        if hasattr(channel, 'git_revision'):
-            v.status('Verifying that fetch retrieved this rev')
-            process = subprocess.run(
-                ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_revision])
-            v.result(process.returncode == 0)
-
-    if not hasattr(channel, 'git_revision'):
-        channel.git_revision = open(
-            os.path.join(
-                channel.git_cachedir,
-                'refs',
-                'heads',
-                channel.git_ref)).read(999).strip()

 
 

+def verify_git_ancestry(v: Verification, channel: Channel) -> None:
+    cachedir = git_cachedir(channel.git_repo)

     v.status('Verifying rev is an ancestor of ref')
     process = subprocess.run(['git',
                               '-C',
     v.status('Verifying rev is an ancestor of ref')
     process = subprocess.run(['git',
                               '-C',

-                              channel.git_cachedir,
+                              cachedir,

                               'merge-base',
                               '--is-ancestor',
                               channel.git_revision,
                               'merge-base',
                               '--is-ancestor',
                               channel.git_revision,


@@ -286,7 +237,7 @@ def git_fetch(v: Verification, channel: Channel) -> None:
             channel.old_git_revision)
         process = subprocess.run(['git',
                                   '-C',
             channel.old_git_revision)
         process = subprocess.run(['git',
                                   '-C',

-                                  channel.git_cachedir,
+                                  cachedir,

                                   'merge-base',
                                   '--is-ancestor',
                                   channel.old_git_revision,
                                   'merge-base',
                                   '--is-ancestor',
                                   channel.old_git_revision,


@@ -294,6 +245,65 @@ def git_fetch(v: Verification, channel: Channel) -> None:
         v.result(process.returncode == 0)
 
 
         v.result(process.returncode == 0)
 
 

+def git_fetch(v: Verification, channel: Channel) -> None:
+    # 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
+    # details for my comfort.  So we re-implement here half of nix.fetchGit.
+    # :(
+
+    cachedir = git_cachedir(channel.git_repo)
+    if not os.path.exists(cachedir):
+        v.status("Initializing git repo")
+        process = subprocess.run(
+            ['git', 'init', '--bare', cachedir])
+        v.result(process.returncode == 0)
+
+    v.status('Fetching ref "%s" from %s' % (channel.git_ref, channel.git_repo))
+    # We don't use --force here because we want to abort and freak out if forced
+    # updates are happening.
+    process = subprocess.run(['git',
+                              '-C',
+                              cachedir,
+                              'fetch',
+                              channel.git_repo,
+                              '%s:%s' % (channel.git_ref,
+                                         channel.git_ref)])
+    v.result(process.returncode == 0)
+
+    if hasattr(channel, 'git_revision'):
+        v.status('Verifying that fetch retrieved this rev')
+        process = subprocess.run(
+            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_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)
+
+
+def ensure_git_rev_available(v: Verification, channel: Channel) -> None:
+    cachedir = git_cachedir(channel.git_repo)
+    if os.path.exists(cachedir):
+        v.status('Checking if we already have this rev:')
+        process = subprocess.run(
+            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_revision])
+        if process.returncode == 0:
+            v.status('yes')
+        if process.returncode == 1:
+            v.status('no')
+        v.result(process.returncode == 0 or process.returncode == 1)
+        if process.returncode == 0:
+            verify_git_ancestry(v, channel)
+            return
+    git_fetch(v, channel)
+
+

 def compare_tarball_and_git(
         v: Verification,
         channel: Channel,
 def compare_tarball_and_git(
         v: Verification,
         channel: Channel,


@@ -340,7 +350,7 @@ def git_checkout(v: Verification, channel: Channel, dest: str) -> None:
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',

-                            channel.git_cachedir,
+                            git_cachedir(channel.git_repo),

                             'archive',
                             channel.git_revision],
                            stdout=subprocess.PIPE)
                             'archive',
                             channel.git_revision],
                            stdout=subprocess.PIPE)


@@ -395,10 +405,26 @@ def pin_channel(v: Verification, channel: Channel) -> None:
     fetch(v, channel)
     parse_channel(v, channel)
     fetch_resources(v, channel)
     fetch(v, channel)
     parse_channel(v, channel)
     fetch_resources(v, channel)

-    git_fetch(v, channel)
+    ensure_git_rev_available(v, channel)

     check_channel_contents(v, channel)
 
 
     check_channel_contents(v, channel)
 
 

+def git_revision_name(v: Verification, channel: Channel) -> str:
+    v.status('Getting commit date')
+    process = subprocess.run(['git',
+                              '-C',
+                              git_cachedir(channel.git_repo),
+                              'lo',
+                              '-n1',
+                              '--format=%ct-%h',
+                              '--abbrev=11',
+                              channel.git_revision],
+                             capture_output=True)
+    v.result(process.returncode == 0 and process.stdout != '')
+    return '%s-%s' % (os.path.basename(channel.git_repo),
+                      process.stdout.decode().strip())
+
+

 def make_channel(conf: configparser.SectionProxy) -> Channel:
     channel = Channel(**dict(conf.items()))
     if hasattr(channel, 'git_revision'):
 def make_channel(conf: configparser.SectionProxy) -> Channel:
     channel = Channel(**dict(conf.items()))
     if hasattr(channel, 'git_revision'):


@@ -420,6 +446,7 @@ def pin(args: argparse.Namespace) -> None:
             config[section]['tarball_sha256'] = channel.table['nixexprs.tar.xz'].digest
         else:
             git_fetch(v, channel)
             config[section]['tarball_sha256'] = channel.table['nixexprs.tar.xz'].digest
         else:
             git_fetch(v, channel)

+            config[section]['name'] = git_revision_name(v, channel)

         config[section]['git_revision'] = channel.git_revision
 
     with open(args.channels_file, 'w') as configfile:
         config[section]['git_revision'] = channel.git_revision
 
     with open(args.channels_file, 'w') as configfile: