2.1.1: Pin faster

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index b5e3b81567894101a9ee0d9cc9de34f253c15dd1..ed33c928ae6a466c5e27a70ccf2a52d592bc8bc8 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -127,6 +127,15 @@ def copy_to_nix_store(v: Verification, filename: str) -> str:
     return process.stdout.decode().strip()  # type: ignore  # (for old mypy)
 
 
+def symlink_archive(v: Verification, path: str) -> str:
+    with tempfile.TemporaryDirectory() as td:
+        archive_filename = os.path.join(td, 'link.tar.gz')
+        os.symlink(path, os.path.join(td, 'link'))
+        with tarfile.open(archive_filename, mode='x:gz') as t:
+            t.add(os.path.join(td, 'link'), arcname='link')
+        return copy_to_nix_store(v, archive_filename)
+
+
 class AliasSearchPath(NamedTuple):
     alias_of: str
 
@@ -143,12 +152,7 @@ class SymlinkSearchPath(NamedTuple):
         return SymlinkPin()
 
     def fetch(self, v: Verification, _: Pin) -> str:
-        with tempfile.TemporaryDirectory() as td:
-            archive_filename = os.path.join(td, 'link.tar.gz')
-            os.symlink(self.path, os.path.join(td, 'link'))
-            with tarfile.open(archive_filename, mode='x:gz') as t:
-                t.add(os.path.join(td, 'link'), arcname='link')
-            return copy_to_nix_store(v, archive_filename)
+        return symlink_archive(v, self.path)
 
 
 class GitSearchPath(NamedTuple):
@@ -182,6 +186,8 @@ class ChannelSearchPath(NamedTuple):
 
         channel_html, forwarded_url = fetch_channel(v, self)
         table, new_gitpin = parse_channel(v, channel_html)
+        if old_pin is not None and old_pin.git_revision == new_gitpin.git_revision:
+            return old_pin
         fetch_resources(v, new_gitpin, forwarded_url, table)
         ensure_git_rev_available(v, self, new_gitpin, old_revision)
         check_channel_contents(v, self, table, new_gitpin)
@@ -723,8 +729,7 @@ def updateCommand(args: argparse.Namespace) -> None:
     command = [
         'nix-env',
         '--profile',
-        '/nix/var/nix/profiles/per-user/%s/channels' %
-        getpass.getuser(),
+        args.profile,
         '--show-trace',
         '--file',
         '<nix/unpack-channel.nix>',
@@ -747,6 +752,8 @@ def main() -> None:
     parser_pin.set_defaults(func=pinCommand)
     parser_update = subparsers.add_parser('update')
     parser_update.add_argument('--dry-run', action='store_true')
+    parser_update.add_argument('--profile', default=(
+        '/nix/var/nix/profiles/per-user/%s/channels' % getpass.getuser()))
     parser_update.add_argument('channels_file', type=str, nargs='+')
     parser_update.set_defaults(func=updateCommand)
     args = parser.parse_args()