]> git.scottworley.com Git - pinch/blobdiff - pinch.py
Polymorphic pin()
[pinch] / pinch.py
index bfc6ac635dfd0866e8cae54d56ac4a9c1daae44f..a90ec3b594e0e51e997017a4af2467b0df8242c9 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -101,7 +101,9 @@ class AliasSearchPath(SearchPath):
         assert not hasattr(self, 'git_repo')
 
 
-class Channel(SearchPath):
+# (This lint-disable is for pylint bug https://github.com/PyCQA/pylint/issues/179
+# which is fixed in pylint 2.5.)
+class TarrableSearchPath(SearchPath, ABC):  # pylint: disable=abstract-method
     channel_html: bytes
     channel_url: str
     forwarded_url: str
@@ -111,21 +113,6 @@ class Channel(SearchPath):
     old_git_revision: str
     table: Dict[str, ChannelTableEntry]
 
-    def pin(self, v: Verification, conf: configparser.SectionProxy) -> None:
-        if hasattr(self, 'git_revision'):
-            self.old_git_revision = self.git_revision
-            del self.git_revision
-
-        if 'channel_url' in conf:
-            pin_channel(v, self)
-            conf['release_name'] = self.release_name
-            conf['tarball_url'] = self.table['nixexprs.tar.xz'].absolute_url
-            conf['tarball_sha256'] = self.table['nixexprs.tar.xz'].digest
-        else:
-            git_fetch(v, self)
-            conf['release_name'] = git_revision_name(v, self)
-        conf['git_revision'] = self.git_revision
-
     def fetch(self, v: Verification, section: str,
               conf: configparser.SectionProxy) -> str:
         if 'git_repo' not in conf or 'release_name' not in conf:
@@ -142,6 +129,30 @@ class Channel(SearchPath):
         return git_get_tarball(v, self)
 
 
+class GitSearchPath(TarrableSearchPath):
+    def pin(self, v: Verification, conf: configparser.SectionProxy) -> None:
+        if hasattr(self, 'git_revision'):
+            self.old_git_revision = self.git_revision
+            del self.git_revision
+
+        git_fetch(v, self)
+        conf['release_name'] = git_revision_name(v, self)
+        conf['git_revision'] = self.git_revision
+
+
+class ChannelSearchPath(TarrableSearchPath):
+    def pin(self, v: Verification, conf: configparser.SectionProxy) -> None:
+        if hasattr(self, 'git_revision'):
+            self.old_git_revision = self.git_revision
+            del self.git_revision
+
+        pin_channel(v, self)
+        conf['release_name'] = self.release_name
+        conf['tarball_url'] = self.table['nixexprs.tar.xz'].absolute_url
+        conf['tarball_sha256'] = self.table['nixexprs.tar.xz'].digest
+        conf['git_revision'] = self.git_revision
+
+
 def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
 
     def throw(error: OSError) -> None:
@@ -170,7 +181,7 @@ def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
     return filecmp.cmpfiles(a, b, files, shallow=False)
 
 
-def fetch(v: Verification, channel: Channel) -> None:
+def fetch(v: Verification, channel: TarrableSearchPath) -> None:
     v.status('Fetching channel')
     request = urllib.request.urlopen(channel.channel_url, timeout=10)
     channel.channel_html = request.read()
@@ -179,7 +190,7 @@ def fetch(v: Verification, channel: Channel) -> None:
     v.check('Got forwarded', channel.channel_url != channel.forwarded_url)
 
 
-def parse_channel(v: Verification, channel: Channel) -> None:
+def parse_channel(v: Verification, channel: TarrableSearchPath) -> None:
     v.status('Parsing channel description as XML')
     d = xml.dom.minidom.parseString(channel.channel_html)
     v.ok()
@@ -259,7 +270,7 @@ def fetch_with_nix_prefetch_url(
     return path  # type: ignore  # (for old mypy)
 
 
-def fetch_resources(v: Verification, channel: Channel) -> None:
+def fetch_resources(v: Verification, channel: TarrableSearchPath) -> None:
     for resource in ['git-revision', 'nixexprs.tar.xz']:
         fields = channel.table[resource]
         fields.absolute_url = urllib.parse.urljoin(
@@ -279,7 +290,7 @@ def git_cachedir(git_repo: str) -> str:
         digest_string(git_repo.encode()))
 
 
-def tarball_cache_file(channel: Channel) -> str:
+def tarball_cache_file(channel: TarrableSearchPath) -> str:
     return os.path.join(
         xdg.XDG_CACHE_HOME,
         'pinch/git-tarball',
@@ -289,7 +300,7 @@ def tarball_cache_file(channel: Channel) -> str:
          channel.release_name))
 
 
-def verify_git_ancestry(v: Verification, channel: Channel) -> None:
+def verify_git_ancestry(v: Verification, channel: TarrableSearchPath) -> None:
     cachedir = git_cachedir(channel.git_repo)
     v.status('Verifying rev is an ancestor of ref')
     process = subprocess.run(['git',
@@ -315,7 +326,7 @@ def verify_git_ancestry(v: Verification, channel: Channel) -> None:
         v.result(process.returncode == 0)
 
 
-def git_fetch(v: Verification, channel: Channel) -> None:
+def git_fetch(v: Verification, channel: TarrableSearchPath) -> 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
@@ -357,7 +368,9 @@ def git_fetch(v: Verification, channel: Channel) -> None:
     verify_git_ancestry(v, channel)
 
 
-def ensure_git_rev_available(v: Verification, channel: Channel) -> None:
+def ensure_git_rev_available(
+        v: Verification,
+        channel: TarrableSearchPath) -> None:
     cachedir = git_cachedir(channel.git_repo)
     if os.path.exists(cachedir):
         v.status('Checking if we already have this rev:')
@@ -376,7 +389,7 @@ def ensure_git_rev_available(v: Verification, channel: Channel) -> None:
 
 def compare_tarball_and_git(
         v: Verification,
-        channel: Channel,
+        channel: TarrableSearchPath,
         channel_contents: str,
         git_contents: str) -> None:
     v.status('Comparing channel tarball with git checkout')
@@ -407,7 +420,10 @@ def compare_tarball_and_git(
         len(benign_errors) == len(expected_errors))
 
 
-def extract_tarball(v: Verification, channel: Channel, dest: str) -> None:
+def extract_tarball(
+        v: Verification,
+        channel: TarrableSearchPath,
+        dest: str) -> None:
     v.status('Extracting tarball %s' %
              channel.table['nixexprs.tar.xz'].file)
     shutil.unpack_archive(
@@ -416,7 +432,10 @@ def extract_tarball(v: Verification, channel: Channel, dest: str) -> None:
     v.ok()
 
 
-def git_checkout(v: Verification, channel: Channel, dest: str) -> None:
+def git_checkout(
+        v: Verification,
+        channel: TarrableSearchPath,
+        dest: str) -> None:
     v.status('Checking out corresponding git revision')
     git = subprocess.Popen(['git',
                             '-C',
@@ -433,7 +452,7 @@ def git_checkout(v: Verification, channel: Channel, dest: str) -> None:
     v.result(git.returncode == 0 and tar.returncode == 0)
 
 
-def git_get_tarball(v: Verification, channel: Channel) -> str:
+def git_get_tarball(v: Verification, channel: TarrableSearchPath) -> str:
     cache_file = tarball_cache_file(channel)
     if os.path.exists(cache_file):
         cached_tarball = open(cache_file).read(9999)
@@ -472,7 +491,7 @@ def git_get_tarball(v: Verification, channel: Channel) -> str:
 
 def check_channel_metadata(
         v: Verification,
-        channel: Channel,
+        channel: TarrableSearchPath,
         channel_contents: str) -> None:
     v.status('Verifying git commit in channel tarball')
     v.result(
@@ -494,7 +513,9 @@ def check_channel_metadata(
     v.result(channel.release_name.endswith(version_suffix))
 
 
-def check_channel_contents(v: Verification, channel: Channel) -> None:
+def check_channel_contents(
+        v: Verification,
+        channel: TarrableSearchPath) -> None:
     with tempfile.TemporaryDirectory() as channel_contents, \
             tempfile.TemporaryDirectory() as git_contents:
 
@@ -509,7 +530,7 @@ def check_channel_contents(v: Verification, channel: Channel) -> None:
     v.ok()
 
 
-def pin_channel(v: Verification, channel: Channel) -> None:
+def pin_channel(v: Verification, channel: TarrableSearchPath) -> None:
     fetch(v, channel)
     parse_channel(v, channel)
     fetch_resources(v, channel)
@@ -517,7 +538,7 @@ def pin_channel(v: Verification, channel: Channel) -> None:
     check_channel_contents(v, channel)
 
 
-def git_revision_name(v: Verification, channel: Channel) -> str:
+def git_revision_name(v: Verification, channel: TarrableSearchPath) -> str:
     v.status('Getting commit date')
     process = subprocess.run(['git',
                               '-C',
@@ -537,7 +558,9 @@ def git_revision_name(v: Verification, channel: Channel) -> str:
 def read_search_path(conf: configparser.SectionProxy) -> SearchPath:
     if 'alias_of' in conf:
         return AliasSearchPath(**dict(conf.items()))
-    return Channel(**dict(conf.items()))
+    if 'channel_url' in conf:
+        return ChannelSearchPath(**dict(conf.items()))
+    return GitSearchPath(**dict(conf.items()))
 
 
 def read_config(filename: str) -> configparser.ConfigParser: