X-Git-Url: http://git.scottworley.com/pinch/blobdiff_plain/b17def3f6b3c3f002d1bf7ef7d838110374d015d..0e5e611d13ab114528838b4ab50b0bf417303877:/pinch.py

diff --git a/pinch.py b/pinch.py
index e3b6882..71496a3 100644
--- 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
@@ -42,6 +42,7 @@ class Channel(types.SimpleNamespace):
     git_ref: str
     git_repo: str
     git_revision: str
+    old_git_revision: str
     release_name: str
     table: Dict[str, ChannelTableEntry]
 
@@ -229,16 +230,22 @@ def git_fetch(v: Verification, channel: Channel) -> None:
             ['git', 'init', '--bare', channel.git_cachedir])
         v.result(process.returncode == 0)
 
-    v.status('Checking if we already have this rev:')
-    process = subprocess.run(
-        ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.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 == 1:
-        v.status('Fetching ref "%s"' % channel.git_ref)
+    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])
+        if process.returncode == 0:
+            v.status('yes')
+        if process.returncode == 1:
+            v.status('no')
+        v.result(process.returncode == 0 or process.returncode == 1)
+        have_rev = process.returncode == 0
+
+    if not have_rev:
+        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',
@@ -249,10 +256,19 @@ def git_fetch(v: Verification, channel: Channel) -> None:
                                   '%s:%s' % (channel.git_ref,
                                              channel.git_ref)])
         v.result(process.returncode == 0)
-        v.status('Verifying that fetch retrieved this rev')
-        process = subprocess.run(
-            ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_revision])
-        v.result(process.returncode == 0)
+        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])
+            v.result(process.returncode == 0)
+
+    if not hasattr(channel, 'git_revision'):
+        channel.git_revision = open(
+            os.path.join(
+                channel.git_cachedir,
+                'refs',
+                'heads',
+                channel.git_ref)).read(999).strip()
 
     v.status('Verifying rev is an ancestor of ref')
     process = subprocess.run(['git',
@@ -264,6 +280,19 @@ def git_fetch(v: Verification, channel: Channel) -> None:
                               channel.git_ref])
     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)
+        process = subprocess.run(['git',
+                                  '-C',
+                                  channel.git_cachedir,
+                                  'merge-base',
+                                  '--is-ancestor',
+                                  channel.old_git_revision,
+                                  channel.git_revision])
+        v.result(process.returncode == 0)
+
 
 def compare_tarball_and_git(
         v: Verification,
@@ -362,22 +391,48 @@ def check_channel_contents(v: Verification, channel: Channel) -> None:
     v.ok()
 
 
-def main(argv: List[str]) -> None:
+def pin_channel(v: Verification, channel: Channel) -> None:
+    fetch(v, channel)
+    parse_channel(v, channel)
+    fetch_resources(v, channel)
+    git_fetch(v, channel)
+    check_channel_contents(v, channel)
+
+
+def make_channel(conf: configparser.SectionProxy) -> Channel:
+    channel = Channel(**dict(conf.items()))
+    if hasattr(channel, 'git_revision'):
+        channel.old_git_revision = channel.git_revision
+        del channel.git_revision
+    return channel
+
+
+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 = Channel(**dict(config[section].items()))
-        fetch(v, channel)
-        parse_channel(v, channel)
-        fetch_resources(v, channel)
-        git_fetch(v, channel)
-        check_channel_contents(v, channel)
-        config[section]['git_rev'] = channel.git_revision
-        config[section]['tarball_url'] = channel.table['nixexprs.tar.xz'].absolute_url
-        config[section]['tarball_sha256'] = channel.table['nixexprs.tar.xz'].digest
-    with open(argv[1], 'w') as configfile:
+        channel = make_channel(config[section])
+        if 'channel_url' in config[section]:
+            pin_channel(v, channel)
+            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]['git_revision'] = channel.git_revision
+
+    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()