Jomik · April 12, 2019 08:15
diff --git a/update.py b/update.py
 #!/usr/bin/env nix-shell
 #!nix-shell -p nix-prefetch-git -p python3 nix -i python3

 # format:
 # $ nix run nixpkgs.python3Packages.black -c black update.py
 # type-check:
 # $ nix run nixpkgs.python3Packages.mypy -c mypy update.py
 # linted:
 # $ nix run nixpkgs.python3Packages.flake8 -c flake8 --ignore E501,E265 update.py

 import functools
 import json
 import os
 import subprocess
 import sys
 import traceback
 import urllib.error
 import urllib.request
 import xml.etree.ElementTree as ET
 from datetime import datetime
 from multiprocessing.dummy import Pool
 from pathlib import Path
 from typing import Dict, List, Optional, Tuple, Union, Any
 from urllib.parse import urljoin, urlparse
 from tempfile import NamedTemporaryFile

 ATOM_ENTRY = "{http://www.w3.org/2005/Atom}entry"
 ATOM_LINK = "{http://www.w3.org/2005/Atom}link"
 ATOM_UPDATED = "{http://www.w3.org/2005/Atom}updated"

 ROOT = Path(__file__).parent


 class Repo:
    def __init__(self, owner: str, name: str) -> None:
        self.owner = owner
        self.name = name

    def url(self, path: str) -> str:
        return urljoin(f"https://github.com/{self.owner}/{self.name}/", path)

    def __repr__(self) -> str:
        return f"Repo({self.owner}, {self.name})"

    def has_submodules(self) -> bool:
        try:
            urllib.request.urlopen(self.url("blob/master/.gitmodules")).close()
        except urllib.error.HTTPError as e:
            if e.code == 404:
                return False
            else:
                raise
        return True

    def latest_commit(self) -> Tuple[str, datetime]:
        with urllib.request.urlopen(self.url("commits/master.atom")) as req:
            xml = req.read()
            root = ET.fromstring(xml)
            latest_entry = root.find(ATOM_ENTRY)
            assert latest_entry is not None, f"No commits found in repository {self}"
            commit_link = latest_entry.find(ATOM_LINK)
            assert commit_link is not None, f"No link tag found feed entry {xml}"
            url = urlparse(commit_link.get("href"))
            updated_tag = latest_entry.find(ATOM_UPDATED)
            assert (
                updated_tag is not None and updated_tag.text is not None
            ), f"No updated tag found feed entry {xml}"
            updated = datetime.strptime(updated_tag.text, "%Y-%m-%dT%H:%M:%SZ")
            return Path(url.path).name, updated

    def prefetch_git(self, ref: str) -> str:
        data = subprocess.check_output(
            ["nix-prefetch-git", "--fetch-submodules", self.url(""), ref]
        )
        return json.loads(data)["sha256"]

    def prefetch_github(self, ref: str) -> str:
        data = subprocess.check_output(
            ["nix-prefetch-url", "--unpack", self.url(f"archive/{ref}.tar.gz")]
        )
        return data.strip().decode("utf-8")


 class Plugin:
    def __init__(
        self,
        name: str,
        commit: str,
        has_submodules: bool,
        sha256: str,
        date: Optional[datetime] = None,
    ) -> None:
        self.name = name
        self.commit = commit
        self.has_submodules = has_submodules
        self.sha256 = sha256
        self.date = date

    @property
    def normalized_name(self) -> str:
        return self.name.replace(".", "-")

    @property
    def version(self) -> str:
        assert self.date is not None
        return self.date.strftime("%Y-%m-%d")

    def as_json(self) -> Dict[str, str]:
        copy = self.__dict__.copy()
        del copy["date"]
        return copy


 GET_PLUGINS = f"""(with import <localpkgs> {{}};
 let
  inherit (pkgs.callPackage ./fish-utils.nix {}) buildFishPlugin;
  generated = callPackage {ROOT}/generated.nix {{
    inherit buildFishPlugin;
  }};
  hasChecksum = value: lib.isAttrs value && lib.hasAttrByPath ["src" "outputHash"] value;
  getChecksum = name: value:
    if hasChecksum value then {{
      submodules = value.src.fetchSubmodules or false;
      sha256 = value.src.outputHash;
      rev = value.src.rev;
    }} else null;
  checksums = lib.mapAttrs getChecksum generated;
 in lib.filterAttrs (n: v: v != null) checksums)"""


 class CleanEnvironment(object):
    def __enter__(self) -> None:
        self.old_environ = os.environ.copy()
        # local_pkgs = str(ROOT.joinpath("../../.."))
        # os.environ["NIX_PATH"] = f"localpkgs={local_pkgs}"
        self.empty_config = NamedTemporaryFile()
        self.empty_config.write(b"{}")
        self.empty_config.flush()
        os.environ["NIXPKGS_CONFIG"] = self.empty_config.name

    def __exit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
        os.environ.update(self.old_environ)
        self.empty_config.close()


 def get_current_plugins() -> List[Plugin]:
    with CleanEnvironment():
        out = subprocess.check_output(["nix", "eval", "--json", GET_PLUGINS])
    data = json.loads(out)
    plugins = []
    for name, attr in data.items():
        p = Plugin(name, attr["rev"], attr["submodules"], attr["sha256"])
        plugins.append(p)
    return plugins


 def prefetch_plugin(user: str, repo_name: str, cache: "Cache") -> Plugin:
    repo = Repo(user, repo_name)
    commit, date = repo.latest_commit()
    has_submodules = repo.has_submodules()
    cached_plugin = cache[commit]
    if cached_plugin is not None:
        cached_plugin.name = repo_name
        cached_plugin.date = date
        return cached_plugin

    print(f"prefetch {user}/{repo_name}")
    if has_submodules:
        sha256 = repo.prefetch_git(commit)
    else:
        sha256 = repo.prefetch_github(commit)

    return Plugin(repo_name, commit, has_submodules, sha256, date=date)


 def print_download_error(plugin: str, ex: Exception):
    print(f"{plugin}: {ex}", file=sys.stderr)
    ex_traceback = ex.__traceback__
    tb_lines = [
        line.rstrip("\n")
        for line in traceback.format_exception(ex.__class__, ex, ex_traceback)
    ]
    print("\n".join(tb_lines))


 def check_results(
    results: List[Tuple[str, str, Union[Exception, Plugin]]]
 ) -> List[Tuple[str, str, Plugin]]:
    failures: List[Tuple[str, Exception]] = []
    plugins = []
    for (owner, name, result) in results:
        if isinstance(result, Exception):
            failures.append((name, result))
        else:
            plugins.append((owner, name, result))

    print(f"{len(results) - len(failures)} plugins were checked", end="")
    if len(failures) == 0:
        print()
        return plugins
    else:
        print(f", {len(failures)} plugin(s) could not be downloaded:\n")

        for (plugin, exception) in failures:
            print_download_error(plugin, exception)

        sys.exit(1)


 def load_plugin_spec() -> List[Tuple[str, str]]:
    plugin_file = ROOT.joinpath("fish-plugin-names")
    plugins = []
    with open(plugin_file) as f:
        for line in f:
            spec = line.strip()
            parts = spec.split("/")
            if len(parts) != 2:
                msg = f"Invalid repository {spec}, must be in the format owner/repo"
                print(msg, file=sys.stderr)
                sys.exit(1)
            plugins.append((parts[0], parts[1]))
    return plugins


 def get_cache_path() -> Optional[Path]:
    xdg_cache = os.environ.get("XDG_CACHE_HOME", None)
    if xdg_cache is None:
        home = os.environ.get("HOME", None)
        if home is None:
            return None
        xdg_cache = str(Path(home, ".cache"))

    return Path(xdg_cache, "fish-plugin-cache.json")


 class Cache:
    def __init__(self, initial_plugins: List[Plugin]) -> None:
        self.cache_file = get_cache_path()

        downloads = {}
        for plugin in initial_plugins:
            downloads[plugin.commit] = plugin
        downloads.update(self.load())
        self.downloads = downloads

    def load(self) -> Dict[str, Plugin]:
        if self.cache_file is None or not self.cache_file.exists():
            return {}

        downloads: Dict[str, Plugin] = {}
        with open(self.cache_file) as f:
            data = json.load(f)
            for attr in data.values():
                p = Plugin(
                    attr["name"], attr["commit"], attr["has_submodules"], attr["sha256"]
                )
                downloads[attr["commit"]] = p
        return downloads

    def store(self) -> None:
        if self.cache_file is None:
            return

        os.makedirs(self.cache_file.parent, exist_ok=True)
        with open(self.cache_file, "w+") as f:
            data = {}
            for name, attr in self.downloads.items():
                data[name] = attr.as_json()
            json.dump(data, f, indent=4, sort_keys=True)

    def __getitem__(self, key: str) -> Optional[Plugin]:
        return self.downloads.get(key, None)

    def __setitem__(self, key: str, value: Plugin) -> None:
        self.downloads[key] = value


 def prefetch(
    args: Tuple[str, str], cache: Cache
 ) -> Tuple[str, str, Union[Exception, Plugin]]:
    assert len(args) == 2
    owner, repo = args
    try:
        plugin = prefetch_plugin(owner, repo, cache)
        cache[plugin.commit] = plugin
        return (owner, repo, plugin)
    except Exception as e:
        return (owner, repo, e)


 header = (
    "# This file has been generated by ./pkgs/fish-plugins/update.py. Do not edit!"
 )


 def generate_nix(plugins: List[Tuple[str, str, Plugin]]):
    sorted_plugins = sorted(plugins, key=lambda v: v[2].name.lower())

    with open(ROOT.joinpath("generated.nix"), "w+") as f:
        f.write(header)
        f.write(
            """
 { lib, buildFishPlugin, fetchFromGitHub, overrides ? (self: super: {}) }:

 let
  packages = ( self:
 {"""
        )
        for owner, repo, plugin in sorted_plugins:
            if plugin.has_submodules:
                submodule_attr = "\n      fetchSubmodules = true;"
            else:
                submodule_attr = ""

            f.write(
                f"""
  {plugin.normalized_name} = buildFishPlugin {{
    pname = "{plugin.normalized_name}";
    version = "{plugin.version}";
    src = fetchFromGitHub {{
      owner = "{owner}";
      repo = "{repo}";
      rev = "{plugin.commit}";
      sha256 = "{plugin.sha256}";{submodule_attr}
    }};
  }};
 """
            )
        f.write("""
 });
 in lib.fix' (lib.extends overrides packages)
 """)
    print("updated generated.nix")


 def main() -> None:
    plugin_names = load_plugin_spec()
    current_plugins = get_current_plugins()
    cache = Cache(current_plugins)

    prefetch_with_cache = functools.partial(prefetch, cache=cache)

    try:
        # synchronous variant for debugging
        # results = map(prefetch_with_cache, plugins)
        pool = Pool(processes=30)
        results = pool.map(prefetch_with_cache, plugin_names)
    finally:
        cache.store()

    plugins = check_results(results)

    generate_nix(plugins)


 if __name__ == "__main__":
    main()
	#!/usr/bin/env nix-shell
	#!nix-shell -p nix-prefetch-git -p python3 nix -i python3

	# format:
	# $ nix run nixpkgs.python3Packages.black -c black update.py
	# type-check:
	# $ nix run nixpkgs.python3Packages.mypy -c mypy update.py
	# linted:
	# $ nix run nixpkgs.python3Packages.flake8 -c flake8 --ignore E501,E265 update.py

	import functools
	import json
	import os
	import subprocess
	import sys
	import traceback
	import urllib.error
	import urllib.request
	import xml.etree.ElementTree as ET
	from datetime import datetime
	from multiprocessing.dummy import Pool
	from pathlib import Path
	from typing import Dict, List, Optional, Tuple, Union, Any
	from urllib.parse import urljoin, urlparse
	from tempfile import NamedTemporaryFile

	ATOM_ENTRY = "{http://www.w3.org/2005/Atom}entry"
	ATOM_LINK = "{http://www.w3.org/2005/Atom}link"
	ATOM_UPDATED = "{http://www.w3.org/2005/Atom}updated"

	ROOT = Path(__file__).parent


	class Repo:
	def __init__(self, owner: str, name: str) -> None:
	self.owner = owner
	self.name = name

	def url(self, path: str) -> str:
	return urljoin(f"https://github.com/{self.owner}/{self.name}/", path)

	def __repr__(self) -> str:
	return f"Repo({self.owner}, {self.name})"

	def has_submodules(self) -> bool:
	try:
	urllib.request.urlopen(self.url("blob/master/.gitmodules")).close()
	except urllib.error.HTTPError as e:
	if e.code == 404:
	return False
	else:
	raise
	return True

	def latest_commit(self) -> Tuple[str, datetime]:
	with urllib.request.urlopen(self.url("commits/master.atom")) as req:
	xml = req.read()
	root = ET.fromstring(xml)
	latest_entry = root.find(ATOM_ENTRY)
	assert latest_entry is not None, f"No commits found in repository {self}"
	commit_link = latest_entry.find(ATOM_LINK)
	assert commit_link is not None, f"No link tag found feed entry {xml}"
	url = urlparse(commit_link.get("href"))
	updated_tag = latest_entry.find(ATOM_UPDATED)
	assert (
	updated_tag is not None and updated_tag.text is not None
	), f"No updated tag found feed entry {xml}"
	updated = datetime.strptime(updated_tag.text, "%Y-%m-%dT%H:%M:%SZ")
	return Path(url.path).name, updated

	def prefetch_git(self, ref: str) -> str:
	data = subprocess.check_output(
	["nix-prefetch-git", "--fetch-submodules", self.url(""), ref]
	)
	return json.loads(data)["sha256"]

	def prefetch_github(self, ref: str) -> str:
	data = subprocess.check_output(
	["nix-prefetch-url", "--unpack", self.url(f"archive/{ref}.tar.gz")]
	)
	return data.strip().decode("utf-8")


	class Plugin:
	def __init__(
	self,
	name: str,
	commit: str,
	has_submodules: bool,
	sha256: str,
	date: Optional[datetime] = None,
	) -> None:
	self.name = name
	self.commit = commit
	self.has_submodules = has_submodules
	self.sha256 = sha256
	self.date = date

	@property
	def normalized_name(self) -> str:
	return self.name.replace(".", "-")

	@property
	def version(self) -> str:
	assert self.date is not None
	return self.date.strftime("%Y-%m-%d")

	def as_json(self) -> Dict[str, str]:
	copy = self.__dict__.copy()
	del copy["date"]
	return copy


	GET_PLUGINS = f"""(with import <localpkgs> {{}};
	let
	inherit (pkgs.callPackage ./fish-utils.nix {}) buildFishPlugin;
	generated = callPackage {ROOT}/generated.nix {{
	inherit buildFishPlugin;
	}};
	hasChecksum = value: lib.isAttrs value && lib.hasAttrByPath ["src" "outputHash"] value;
	getChecksum = name: value:
	if hasChecksum value then {{
	submodules = value.src.fetchSubmodules or false;
	sha256 = value.src.outputHash;
	rev = value.src.rev;
	}} else null;
	checksums = lib.mapAttrs getChecksum generated;
	in lib.filterAttrs (n: v: v != null) checksums)"""


	class CleanEnvironment(object):
	def __enter__(self) -> None:
	self.old_environ = os.environ.copy()
	# local_pkgs = str(ROOT.joinpath("../../.."))
	# os.environ["NIX_PATH"] = f"localpkgs={local_pkgs}"
	self.empty_config = NamedTemporaryFile()
	self.empty_config.write(b"{}")
	self.empty_config.flush()
	os.environ["NIXPKGS_CONFIG"] = self.empty_config.name

	def __exit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
	os.environ.update(self.old_environ)
	self.empty_config.close()


	def get_current_plugins() -> List[Plugin]:
	with CleanEnvironment():
	out = subprocess.check_output(["nix", "eval", "--json", GET_PLUGINS])
	data = json.loads(out)
	plugins = []
	for name, attr in data.items():
	p = Plugin(name, attr["rev"], attr["submodules"], attr["sha256"])
	plugins.append(p)
	return plugins


	def prefetch_plugin(user: str, repo_name: str, cache: "Cache") -> Plugin:
	repo = Repo(user, repo_name)
	commit, date = repo.latest_commit()
	has_submodules = repo.has_submodules()
	cached_plugin = cache[commit]
	if cached_plugin is not None:
	cached_plugin.name = repo_name
	cached_plugin.date = date
	return cached_plugin

	print(f"prefetch {user}/{repo_name}")
	if has_submodules:
	sha256 = repo.prefetch_git(commit)
	else:
	sha256 = repo.prefetch_github(commit)

	return Plugin(repo_name, commit, has_submodules, sha256, date=date)


	def print_download_error(plugin: str, ex: Exception):
	print(f"{plugin}: {ex}", file=sys.stderr)
	ex_traceback = ex.__traceback__
	tb_lines = [
	line.rstrip("\n")
	for line in traceback.format_exception(ex.__class__, ex, ex_traceback)
	]
	print("\n".join(tb_lines))


	def check_results(
	results: List[Tuple[str, str, Union[Exception, Plugin]]]
	) -> List[Tuple[str, str, Plugin]]:
	failures: List[Tuple[str, Exception]] = []
	plugins = []
	for (owner, name, result) in results:
	if isinstance(result, Exception):
	failures.append((name, result))
	else:
	plugins.append((owner, name, result))

	print(f"{len(results) - len(failures)} plugins were checked", end="")
	if len(failures) == 0:
	print()
	return plugins
	else:
	print(f", {len(failures)} plugin(s) could not be downloaded:\n")

	for (plugin, exception) in failures:
	print_download_error(plugin, exception)

	sys.exit(1)


	def load_plugin_spec() -> List[Tuple[str, str]]:
	plugin_file = ROOT.joinpath("fish-plugin-names")
	plugins = []
	with open(plugin_file) as f:
	for line in f:
	spec = line.strip()
	parts = spec.split("/")
	if len(parts) != 2:
	msg = f"Invalid repository {spec}, must be in the format owner/repo"
	print(msg, file=sys.stderr)
	sys.exit(1)
	plugins.append((parts[0], parts[1]))
	return plugins


	def get_cache_path() -> Optional[Path]:
	xdg_cache = os.environ.get("XDG_CACHE_HOME", None)
	if xdg_cache is None:
	home = os.environ.get("HOME", None)
	if home is None:
	return None
	xdg_cache = str(Path(home, ".cache"))

	return Path(xdg_cache, "fish-plugin-cache.json")


	class Cache:
	def __init__(self, initial_plugins: List[Plugin]) -> None:
	self.cache_file = get_cache_path()

	downloads = {}
	for plugin in initial_plugins:
	downloads[plugin.commit] = plugin
	downloads.update(self.load())
	self.downloads = downloads

	def load(self) -> Dict[str, Plugin]:
	if self.cache_file is None or not self.cache_file.exists():
	return {}

	downloads: Dict[str, Plugin] = {}
	with open(self.cache_file) as f:
	data = json.load(f)
	for attr in data.values():
	p = Plugin(
	attr["name"], attr["commit"], attr["has_submodules"], attr["sha256"]
	)
	downloads[attr["commit"]] = p
	return downloads

	def store(self) -> None:
	if self.cache_file is None:
	return

	os.makedirs(self.cache_file.parent, exist_ok=True)
	with open(self.cache_file, "w+") as f:
	data = {}
	for name, attr in self.downloads.items():
	data[name] = attr.as_json()
	json.dump(data, f, indent=4, sort_keys=True)

	def __getitem__(self, key: str) -> Optional[Plugin]:
	return self.downloads.get(key, None)

	def __setitem__(self, key: str, value: Plugin) -> None:
	self.downloads[key] = value


	def prefetch(
	args: Tuple[str, str], cache: Cache
	) -> Tuple[str, str, Union[Exception, Plugin]]:
	assert len(args) == 2
	owner, repo = args
	try:
	plugin = prefetch_plugin(owner, repo, cache)
	cache[plugin.commit] = plugin
	return (owner, repo, plugin)
	except Exception as e:
	return (owner, repo, e)


	header = (
	"# This file has been generated by ./pkgs/fish-plugins/update.py. Do not edit!"
	)


	def generate_nix(plugins: List[Tuple[str, str, Plugin]]):
	sorted_plugins = sorted(plugins, key=lambda v: v[2].name.lower())

	with open(ROOT.joinpath("generated.nix"), "w+") as f:
	f.write(header)
	f.write(
	"""
	{ lib, buildFishPlugin, fetchFromGitHub, overrides ? (self: super: {}) }:

	let
	packages = ( self:
	{"""
	)
	for owner, repo, plugin in sorted_plugins:
	if plugin.has_submodules:
	submodule_attr = "\n fetchSubmodules = true;"
	else:
	submodule_attr = ""

	f.write(
	f"""
	{plugin.normalized_name} = buildFishPlugin {{
	pname = "{plugin.normalized_name}";
	version = "{plugin.version}";
	src = fetchFromGitHub {{
	owner = "{owner}";
	repo = "{repo}";
	rev = "{plugin.commit}";
	sha256 = "{plugin.sha256}";{submodule_attr}
	}};
	}};
	"""
	)
	f.write("""
	});
	in lib.fix' (lib.extends overrides packages)
	""")
	print("updated generated.nix")


	def main() -> None:
	plugin_names = load_plugin_spec()
	current_plugins = get_current_plugins()
	cache = Cache(current_plugins)

	prefetch_with_cache = functools.partial(prefetch, cache=cache)

	try:
	# synchronous variant for debugging
	# results = map(prefetch_with_cache, plugins)
	pool = Pool(processes=30)
	results = pool.map(prefetch_with_cache, plugin_names)
	finally:
	cache.store()

	plugins = check_results(results)

	generate_nix(plugins)


	if __name__ == "__main__":
	main()