Make fetch_channel a Channel method

[pinch] / pinch.py

diff --git a/pinch.py b/pinch.py
index 47f4e34a261779d1a880a7693e8cc66b22f2f871..632994b8061a32a24f7c1e0bdfdd8252ffc17d72 100644 (file)
--- a/pinch.py
+++ b/pinch.py
@@ -38,31 +38,6 @@ xdg = XDG(
         os.path.expanduser('~/.cache')))
 
 
-Digest16 = NewType('Digest16', str)
-Digest32 = NewType('Digest32', str)
-
-
-class ChannelTableEntry(types.SimpleNamespace):
-    absolute_url: str
-    digest: Digest16
-    file: str
-    size: int
-    url: str
-
-
-class Channel(types.SimpleNamespace):
-    alias_of: str
-    channel_html: bytes
-    channel_url: str
-    forwarded_url: str
-    git_ref: str
-    git_repo: str
-    git_revision: str
-    old_git_revision: str
-    release_name: str
-    table: Dict[str, ChannelTableEntry]
-
-
 class VerificationError(Exception):
     pass
 
@@ -98,6 +73,68 @@ class Verification:
         self.result(True)
 
 
+Digest16 = NewType('Digest16', str)
+Digest32 = NewType('Digest32', str)
+
+
+class ChannelTableEntry(types.SimpleNamespace):
+    absolute_url: str
+    digest: Digest16
+    file: str
+    size: int
+    url: str
+
+
+class SearchPath(types.SimpleNamespace):
+    release_name: str
+
+
+class Channel(SearchPath):
+    alias_of: str
+    channel_html: bytes
+    channel_url: str
+    forwarded_url: str
+    git_ref: str
+    git_repo: str
+    git_revision: str
+    old_git_revision: str
+    table: Dict[str, ChannelTableEntry]
+
+    def pin(self, v: Verification, conf: configparser.SectionProxy) -> None:
+        if hasattr(self, 'alias_of'):
+            assert not hasattr(self, 'git_repo')
+            return
+
+        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:
+            raise Exception(
+                'Cannot update unpinned channel "%s" (Run "pin" before "update")' %
+                section)
+
+        if 'channel_url' in conf:
+            return fetch_with_nix_prefetch_url(
+                v, conf['tarball_url'], Digest16(
+                    conf['tarball_sha256']))
+
+        ensure_git_rev_available(v, self)
+        return git_get_tarball(v, self)
+
+
 def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
 
     def throw(error: OSError) -> None:
@@ -490,6 +527,10 @@ def git_revision_name(v: Verification, channel: Channel) -> str:
                       process.stdout.decode().strip())
 
 
+def read_search_path(conf: configparser.SectionProxy) -> Channel:
+    return Channel(**dict(conf.items()))
+
+
 def read_config(filename: str) -> configparser.ConfigParser:
     config = configparser.ConfigParser()
     config.read_file(open(filename), filename)
@@ -503,49 +544,14 @@ def pin(args: argparse.Namespace) -> None:
         if args.channels and section not in args.channels:
             continue
 
-        channel = Channel(**dict(config[section].items()))
+        channel = read_search_path(config[section])
 
-        if hasattr(channel, 'alias_of'):
-            assert not hasattr(channel, 'git_repo')
-            continue
-
-        if hasattr(channel, 'git_revision'):
-            channel.old_git_revision = channel.git_revision
-            del channel.git_revision
-
-        if 'channel_url' in config[section]:
-            pin_channel(v, channel)
-            config[section]['release_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]['release_name'] = git_revision_name(v, channel)
-        config[section]['git_revision'] = channel.git_revision
+        channel.pin(v, config[section])
 
     with open(args.channels_file, 'w') as configfile:
         config.write(configfile)
 
 
-def fetch_channel(
-        v: Verification,
-        section: str,
-        conf: configparser.SectionProxy) -> str:
-    if 'git_repo' not in conf or 'release_name' not in conf:
-        raise Exception(
-            'Cannot update unpinned channel "%s" (Run "pin" before "update")' %
-            section)
-
-    if 'channel_url' in conf:
-        return fetch_with_nix_prefetch_url(
-            v, conf['tarball_url'], Digest16(
-                conf['tarball_sha256']))
-
-    channel = Channel(**dict(conf.items()))
-    ensure_git_rev_available(v, channel)
-    return git_get_tarball(v, channel)
-
-
 def update(args: argparse.Namespace) -> None:
     v = Verification()
     config = configparser.ConfigParser()
@@ -556,7 +562,8 @@ def update(args: argparse.Namespace) -> None:
             if 'alias_of' in config[section]:
                 assert 'git_repo' not in config[section]
                 continue
-            tarball = fetch_channel(v, section, config[section])
+            sp = read_search_path(config[section])
+            tarball = sp.fetch(v, section, config[section])
             if section in exprs:
                 raise Exception('Duplicate channel "%s"' % section)
             exprs[section] = (