]> git.scottworley.com Git - pinch/blobdiff - pinch.py
Start on 3.0.6
[pinch] / pinch.py
index 9b845e3414df7a5c66a0cd940890a8562ebf7da8..18055dc9a00d9f2190e8b9ab101a8a16a27b66c6 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -11,6 +11,7 @@ import shlex
 import shutil
 import subprocess
 import sys
+import tarfile
 import tempfile
 import types
 import urllib.parse
@@ -33,6 +34,8 @@ from typing import (
     Union,
 )
 
+import git_cache
+
 # Use xdg module when it's less painful to have as a dependency
 
 
@@ -97,6 +100,12 @@ class AliasPin(NamedTuple):
     pass
 
 
+class SymlinkPin(NamedTuple):
+    @property
+    def release_name(self) -> str:
+        return 'link'
+
+
 class GitPin(NamedTuple):
     git_revision: str
     release_name: str
@@ -109,7 +118,24 @@ class ChannelPin(NamedTuple):
     tarball_sha256: str
 
 
-Pin = Union[AliasPin, GitPin, ChannelPin]
+Pin = Union[AliasPin, SymlinkPin, GitPin, ChannelPin]
+
+
+def copy_to_nix_store(v: Verification, filename: str) -> str:
+    v.status('Putting tarball in Nix store')
+    process = subprocess.run(
+        ['nix-store', '--add', filename], stdout=subprocess.PIPE)
+    v.result(process.returncode == 0)
+    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):
@@ -120,22 +146,33 @@ class AliasSearchPath(NamedTuple):
         return AliasPin()
 
 
+class SymlinkSearchPath(NamedTuple):
+    path: str
+
+    # pylint: disable=no-self-use
+    def pin(self, _: Verification, __: Optional[Pin]) -> SymlinkPin:
+        return SymlinkPin()
+
+    def fetch(self, v: Verification, _: Pin) -> str:
+        return symlink_archive(v, self.path)
+
+
 class GitSearchPath(NamedTuple):
     git_ref: str
     git_repo: str
 
     def pin(self, v: Verification, old_pin: Optional[Pin]) -> GitPin:
+        _, new_revision = git_cache.fetch(self.git_repo, self.git_ref)
         if old_pin is not None:
             assert isinstance(old_pin, GitPin)
-        old_revision = old_pin.git_revision if old_pin is not None else None
-
-        new_revision = git_fetch(v, self, None, old_revision)
+            verify_git_ancestry(v, self, old_pin.git_revision, new_revision)
         return GitPin(release_name=git_revision_name(v, self, new_revision),
                       git_revision=new_revision)
 
     def fetch(self, v: Verification, pin: Pin) -> str:
         assert isinstance(pin, GitPin)
-        ensure_git_rev_available(v, self, pin, None)
+        git_cache.ensure_rev_available(
+            self.git_repo, self.git_ref, pin.git_revision)
         return git_get_tarball(v, self, pin)
 
 
@@ -147,12 +184,17 @@ class ChannelSearchPath(NamedTuple):
     def pin(self, v: Verification, old_pin: Optional[Pin]) -> ChannelPin:
         if old_pin is not None:
             assert isinstance(old_pin, ChannelPin)
-        old_revision = old_pin.git_revision if old_pin is not None else None
 
         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)
+        git_cache.ensure_rev_available(
+            self.git_repo, self.git_ref, new_gitpin.git_revision)
+        if old_pin is not None:
+            verify_git_ancestry(
+                v, self, old_pin.git_revision, new_gitpin.git_revision)
         check_channel_contents(v, self, table, new_gitpin)
         return ChannelPin(
             release_name=new_gitpin.release_name,
@@ -168,7 +210,10 @@ class ChannelSearchPath(NamedTuple):
             v, pin.tarball_url, Digest16(pin.tarball_sha256))
 
 
-SearchPath = Union[AliasSearchPath, GitSearchPath, ChannelSearchPath]
+SearchPath = Union[AliasSearchPath,
+                   SymlinkSearchPath,
+                   GitSearchPath,
+                   ChannelSearchPath]
 TarrableSearchPath = Union[GitSearchPath, ChannelSearchPath]
 
 
@@ -204,7 +249,7 @@ def fetch_channel(
         v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]:
     v.status('Fetching channel')
     request = urllib.request.urlopen(channel.channel_url, timeout=10)
-    channel_html = request.read()
+    channel_html = request.read().decode()
     forwarded_url = request.geturl()
     v.result(request.status == 200)  # type: ignore  # (for old mypy)
     v.check('Got forwarded', channel.channel_url != forwarded_url)
@@ -257,18 +302,39 @@ def digest_file(filename: str) -> Digest16:
     return Digest16(hasher.hexdigest())
 
 
+@functools.lru_cache
+def _experimental_flag_needed(v: Verification) -> bool:
+    v.status('Checking Nix version')
+    process = subprocess.run(['nix', '--help'], stdout=subprocess.PIPE)
+    v.result(process.returncode == 0)
+    return b'--experimental-features' in process.stdout
+
+
+def _nix_command(v: Verification) -> List[str]:
+    return ['nix', '--experimental-features',
+            'nix-command'] if _experimental_flag_needed(v) else ['nix']
+
+
 def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
     v.status('Converting digest to base16')
-    process = subprocess.run(
-        ['nix', 'to-base16', '--type', 'sha256', digest32], stdout=subprocess.PIPE)
+    process = subprocess.run(_nix_command(v) + [
+        'to-base16',
+        '--type',
+        'sha256',
+        digest32],
+        stdout=subprocess.PIPE)
     v.result(process.returncode == 0)
     return Digest16(process.stdout.decode().strip())
 
 
 def to_Digest32(v: Verification, digest16: Digest16) -> Digest32:
     v.status('Converting digest to base32')
-    process = subprocess.run(
-        ['nix', 'to-base32', '--type', 'sha256', digest16], stdout=subprocess.PIPE)
+    process = subprocess.run(_nix_command(v) + [
+        'to-base32',
+        '--type',
+        'sha256',
+        digest16],
+        stdout=subprocess.PIPE)
     v.result(process.returncode == 0)
     return Digest32(process.stdout.decode().strip())
 
@@ -285,7 +351,7 @@ def fetch_with_nix_prefetch_url(
     assert empty == ''
     v.check("Verifying nix-prefetch-url's digest",
             to_Digest16(v, Digest32(prefetch_digest)) == digest)
-    v.status("Verifying file digest")
+    v.status("Verifying digest of %s" % path)
     file_digest = digest_file(path)
     v.result(file_digest == digest)
     return path  # type: ignore  # (for old mypy)
@@ -305,13 +371,6 @@ def fetch_resources(
     v.result(open(table['git-revision'].file).read(999) == pin.git_revision)
 
 
-def git_cachedir(git_repo: str) -> str:
-    return os.path.join(
-        xdg.XDG_CACHE_HOME,
-        'pinch/git',
-        digest_string(git_repo.encode()))
-
-
 def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
     return os.path.join(
         xdg.XDG_CACHE_HOME,
@@ -325,101 +384,19 @@ def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
 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')
+        old_revision: str,
+        new_revision: str) -> None:
+    cachedir = git_cache.git_cachedir(channel.git_repo)
+    v.status('Verifying rev is an ancestor of previous rev %s' % old_revision)
     process = subprocess.run(['git',
                               '-C',
                               cachedir,
                               'merge-base',
                               '--is-ancestor',
-                              new_revision,
-                              channel.git_ref])
+                              old_revision,
+                              new_revision])
     v.result(process.returncode == 0)
 
-    if old_revision is not None:
-        v.status(
-            'Verifying rev is an ancestor of previous rev %s' %
-            old_revision)
-        process = subprocess.run(['git',
-                                  '-C',
-                                  cachedir,
-                                  'merge-base',
-                                  '--is-ancestor',
-                                  old_revision,
-                                  new_revision])
-        v.result(process.returncode == 0)
-
-
-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
-    # 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 desired_revision is not None:
-        v.status('Verifying that fetch retrieved this rev')
-        process = subprocess.run(
-            ['git', '-C', cachedir, 'cat-file', '-e', desired_revision])
-        v.result(process.returncode == 0)
-
-    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,
-        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:')
-        process = subprocess.run(
-            ['git', '-C', cachedir, 'cat-file', '-e', pin.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, pin.git_revision, old_revision)
-            return
-    git_fetch(v, channel, pin.git_revision, old_revision)
-
 
 def compare_tarball_and_git(
         v: Verification,
@@ -471,7 +448,7 @@ def git_checkout(
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',
-                            git_cachedir(channel.git_repo),
+                            git_cache.git_cachedir(channel.git_repo),
                             'archive',
                             pin.git_revision],
                            stdout=subprocess.PIPE)
@@ -503,7 +480,7 @@ def git_get_tarball(
                 pin.git_revision)
             git = subprocess.Popen(['git',
                                     '-C',
-                                    git_cachedir(channel.git_repo),
+                                    git_cache.git_cachedir(channel.git_repo),
                                     'archive',
                                     '--prefix=%s/' % pin.release_name,
                                     pin.git_revision],
@@ -513,11 +490,7 @@ def git_get_tarball(
             git.wait()
             v.result(git.returncode == 0 and xz.returncode == 0)
 
-        v.status('Putting tarball in Nix store')
-        process = subprocess.run(
-            ['nix-store', '--add', output_filename], stdout=subprocess.PIPE)
-        v.result(process.returncode == 0)
-        store_tarball = process.stdout.decode().strip()
+        store_tarball = copy_to_nix_store(v, output_filename)
 
         os.makedirs(os.path.dirname(cache_file), exist_ok=True)
         open(cache_file, 'w').write(store_tarball)
@@ -574,7 +547,7 @@ def git_revision_name(
     v.status('Getting commit date')
     process = subprocess.run(['git',
                               '-C',
-                              git_cachedir(channel.git_repo),
+                              git_cache.git_cachedir(channel.git_repo),
                               'log',
                               '-n1',
                               '--format=%ct-%h',
@@ -614,13 +587,14 @@ def read_config_section(
         'alias': (AliasSearchPath, AliasPin),
         'channel': (ChannelSearchPath, ChannelPin),
         'git': (GitSearchPath, GitPin),
+        'symlink': (SymlinkSearchPath, SymlinkPin),
     }
     SP, P = mapping[conf['type']]
     _, all_fields = filter_dict(dict(conf.items()), set(['type']))
     pin_fields, remaining_fields = filter_dict(all_fields, set(P._fields))
     # Error suppression works around https://github.com/python/mypy/issues/9007
     pin_present = pin_fields != {} or P._fields == ()
-    pin = P(**pin_fields) if pin_present else None  # type:ignore[call-arg]
+    pin = P(**pin_fields) if pin_present else None  # type: ignore
     return SP(**remaining_fields), pin
 
 
@@ -692,8 +666,7 @@ 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>',
@@ -716,6 +689,8 @@ 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()