git_cachedir without Channel

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index 774f5f108ae9ed23b94b1a2bfb97005c6ed3da93..3e725e171557e1bd4c484a130dc89422e2277083 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -1,3 +1,4 @@
+import argparse
 import configparser
 import filecmp
 import functools
@@ -7,7 +8,6 @@ import os
 import os.path
 import shutil
 import subprocess
-import sys
 import tempfile
 import types
 import urllib.parse
@@ -38,7 +38,6 @@ class Channel(types.SimpleNamespace):
     channel_html: bytes
     channel_url: str
     forwarded_url: str
-    git_cachedir: str
     git_ref: str
     git_repo: str
     git_revision: str
@@ -211,6 +210,10 @@ def fetch_resources(v: Verification, channel: Channel) -> None:
         open(
             channel.table['git-revision'].file).read(999) == channel.git_revision)
 
+def git_cachedir(git_repo: str) -> str:
+    # TODO: Consider using pyxdg to find this path.
+    return os.path.expanduser('~/.cache/nix-pin-channel/git/%s' % digest_string(git_repo.encode()))
+
 
 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
@@ -219,22 +222,18 @@ def git_fetch(v: Verification, channel: Channel) -> None:
     # details for my comfort.  So we re-implement here half of nix.fetchGit.
     # :(
 
-    # TODO: Consider using pyxdg to find this path.
-    channel.git_cachedir = os.path.expanduser(
-        '~/.cache/nix-pin-channel/git/%s' %
-        digest_string(
-            channel.git_repo.encode()))
-    if not os.path.exists(channel.git_cachedir):
+    cachedir = git_cachedir(channel.git_repo)
+    if not os.path.exists(cachedir):
         v.status("Initializing git repo")
         process = subprocess.run(
-            ['git', 'init', '--bare', channel.git_cachedir])
+            ['git', 'init', '--bare', 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])
+            ['git', '-C', cachedir, 'cat-file', '-e', channel.git_revision])
         if process.returncode == 0:
             v.status('yes')
         if process.returncode == 1:
@@ -243,12 +242,14 @@ def git_fetch(v: Verification, channel: Channel) -> None:
         have_rev = process.returncode == 0
 
     if not have_rev:
-        v.status('Fetching ref "%s" from %s' % (channel.git_ref, channel.git_repo))
+        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,
+                                  cachedir,
                                   'fetch',
                                   channel.git_repo,
                                   '%s:%s' % (channel.git_ref,
@@ -257,13 +258,13 @@ def git_fetch(v: Verification, channel: Channel) -> None:
         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])
+                ['git', '-C', 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,
+                cachedir,
                 'refs',
                 'heads',
                 channel.git_ref)).read(999).strip()
@@ -271,7 +272,7 @@ def git_fetch(v: Verification, channel: Channel) -> None:
     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,
@@ -279,10 +280,12 @@ def git_fetch(v: Verification, channel: Channel) -> None:
     v.result(process.returncode == 0)
 
     if hasattr(channel, 'old_git_revision'):
-        v.status('Verifying rev is an ancestor of previous rev %s' % channel.old_git_revision)
+        v.status(
+            'Verifying rev is an ancestor of previous rev %s' %
+            channel.old_git_revision)
         process = subprocess.run(['git',
                                   '-C',
-                                  channel.git_cachedir,
+                                  cachedir,
                                   'merge-base',
                                   '--is-ancestor',
                                   channel.old_git_revision,
@@ -336,7 +339,7 @@ def git_checkout(v: Verification, channel: Channel, dest: str) -> None:
     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)
@@ -395,6 +398,22 @@ def pin_channel(v: Verification, channel: Channel) -> None:
     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'):
@@ -403,22 +422,34 @@ def make_channel(conf: configparser.SectionProxy) -> Channel:
     return channel
 
 
-def main(argv: List[str]) -> None:
+def pin(args: argparse.Namespace) -> None:
     v = Verification()
     config = configparser.ConfigParser()
-    config.read_file(open(argv[1]), argv[1])
+    config.read_file(open(args.channels_file), args.channels_file)
     for section in config.sections():
         channel = make_channel(config[section])
         if 'channel_url' in config[section]:
             pin_channel(v, channel)
+            config[section]['name'] = channel.release_name
             config[section]['tarball_url'] = channel.table['nixexprs.tar.xz'].absolute_url
             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(argv[1], 'w') as configfile:
+    with open(args.channels_file, 'w') as configfile:
         config.write(configfile)
 
 
-main(sys.argv)
+def main() -> None:
+    parser = argparse.ArgumentParser(prog='pinch')
+    subparsers = parser.add_subparsers(dest='mode', required=True)
+    parser_pin = subparsers.add_parser('pin')
+    parser_pin.add_argument('channels_file', type=str)
+    parser_pin.set_defaults(func=pin)
+    args = parser.parse_args()
+    args.func(args)
+
+
+main()