Bazel: allow installer script to install into multiple directories, in parallel

misc/bazel/internal/install.py

@@ -5,56 +5,145 @@
 * resolving destination directory with respect to a provided `--build-file`
 * clean-up of target destination directory before a reinstall
 * installing imported zip files using a provided `--ripunzip`
+
+This also allows installing onto multiple targets:
+* multiple --pkg-install-script and --zip-manifest options can be passed
+* --subdir can be used to change installation directory with respect to --destdir (an implicit initial --subdir=. is
+  implied)
+
+Install actions are carried out in parallel.
 """
 
 import argparse
 import pathlib
 import shutil
 import subprocess
+import concurrent.futures
+import dataclasses
+import typing
 from python.runfiles import runfiles
 
 runfiles = runfiles.Create()
 assert runfiles, "Installer should be run with `bazel run`"
 
-parser = argparse.ArgumentParser(description=__doc__)
-parser.add_argument("--destdir", type=pathlib.Path, required=True,
-                    help="Desination directory, relative to `--build-file`")
-parser.add_argument("--pkg-install-script", required=True,
-                    help="The wrapped `pkg_install` installation script rlocation")
-parser.add_argument("--build-file",
-                    help="BUILD.bazel rlocation relative to which the installation should take place")
-parser.add_argument("--ripunzip",
-                    help="ripunzip executable rlocation. Must be provided if `--zip-manifest` is.")
-parser.add_argument("--zip-manifest",
-                    help="The rlocation of a file containing newline-separated `prefix:zip_file` entries")
-parser.add_argument("--cleanup", action=argparse.BooleanOptionalAction, default=True,
-                    help="Whether to wipe the destination directory before installing (true by default)")
-opts = parser.parse_args()
-if opts.zip_manifest and not opts.ripunzip:
-    parser.error("Provide `--ripunzip` when specifying `--zip-manifest`")
-
-if opts.build_file:
-    build_file = runfiles.Rlocation(opts.build_file)
-    destdir = pathlib.Path(build_file).resolve().parent / opts.destdir
-else:
-    destdir = pathlib.Path(opts.destdir)
-    assert destdir.is_absolute(), "Provide `--build-file` to resolve destination directory"
-script = runfiles.Rlocation(opts.pkg_install_script)
-
-if destdir.exists() and opts.cleanup:
-    shutil.rmtree(destdir)
-
-destdir.mkdir(parents=True, exist_ok=True)
-subprocess.run([script, "--destdir", destdir], check=True)
-
-if opts.zip_manifest:
-    ripunzip = runfiles.Rlocation(opts.ripunzip)
-    zip_manifest = runfiles.Rlocation(opts.zip_manifest)
-    with open(zip_manifest) as manifest:
-        for line in manifest:
-            prefix, _, zip = line.partition(":")
-            assert zip, f"missing prefix for {prefix}, you should use prefix:zip format"
-            zip = zip.strip()
-            dest = destdir / prefix
-            dest.mkdir(parents=True, exist_ok=True)
-            subprocess.run([ripunzip, "unzip-file", zip, "-d", dest], check=True)
+
+def options():
+    parser = argparse.ArgumentParser(description=__doc__)
+    actions = {pathlib.Path(): []}
+    parser.set_defaults(actions=actions, current_destdir_actions=actions[pathlib.Path()])
+    parser.add_argument("--destdir", type=pathlib.Path,
+                        help="Base desination directory, relative to `--build-file` if provided")
+    parser.add_argument("--subdir", action=ChangeDestDir,
+                        help="Subdirectory of `--destdir` to use for following install actions")
+    parser.add_argument("--pkg-install-script", type=ScriptInstruction, action=AppendInstruction,
+                        help="The wrapped `pkg_install` installation script rlocation")
+    parser.add_argument("--zip-manifest", type=ZipInstruction, action=AppendInstruction,
+                        help="The rlocation of a file containing newline-separated `prefix:zip_file` entries")
+    parser.add_argument("--build-file",
+                        help="BUILD.bazel rlocation relative to which the installation should take place")
+    parser.add_argument("--ripunzip",
+                        help="ripunzip executable rlocation. Must be provided if `--zip-manifest` is.")
+    parser.add_argument("--cleanup", action=argparse.BooleanOptionalAction, default=True,
+                        help="Whether to wipe the destination directories before installing (true by default)")
+    return parser.parse_args()
+
+
+class ChangeDestDir(argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        namespace.current_destdir_actions = namespace.actions.setdefault(values, [])
+
+
+class AppendInstruction(argparse.Action):
+    def __call__(self, parser, namespace, values, option_string=None):
+        namespace.current_destdir_actions.append(values)
+
+
+class Task:
+    def run(self):
+        ...
+
+
+class Instruction:
+    def tasks(self, target: pathlib.Path, ripunzip: str | None) -> typing.Iterable[Task]:
+        ...
+
+
+@dataclasses.dataclass
+class ScriptInstruction(Instruction):
+    script: str
+
+    def tasks(self, target: pathlib.Path, ripunzip: str | None):
+        return (ScriptTask(pathlib.Path(runfiles.Rlocation(self.script)), target),)
+
+
+@dataclasses.dataclass
+class ScriptTask(Task):
+    script: pathlib.Path
+    target: pathlib.Path
+
+    def run(self):
+        subprocess.run([self.script, "--destdir", self.target], check=True)
+
+    def __str__(self):
+        return f"run {self.script.name} into {self.target}"
+
+
+@dataclasses.dataclass
+class ZipInstruction(Instruction):
+    manifest: str
+
+    def tasks(self, target: pathlib.Path, ripunzip: str | None):
+        assert ripunzip, "--ripunzip must be provided when --zip-manifest is"
+        manifest_file = runfiles.Rlocation(self.manifest)
+        with open(manifest_file) as manifest:
+            for line in manifest:
+                prefix, _, zip = line.partition(":")
+                assert zip, f"missing prefix for {prefix}, you should use prefix:zip format"
+                zip = zip.strip()
+                yield ZipTask(prefix, pathlib.Path(zip), target, ripunzip)
+
+
+@dataclasses.dataclass
+class ZipTask(Task):
+    prefix: str
+    zip: pathlib.Path
+    target: pathlib.Path
+    ripunzip: str
+
+    def run(self):
+        dest = self.target / self.prefix
+        dest.mkdir(parents=True, exist_ok=True)
+        subprocess.run([self.ripunzip, "unzip-file", self.zip, "-d", dest], check=True, stderr=subprocess.DEVNULL)
+
+    def __str__(self):
+        return f"extracted {self.zip.name} to {self.target / self.prefix}"
+
+
+def main():
+    opts = options()
+    if opts.build_file:
+        basedir = pathlib.Path(runfiles.Rlocation(opts.build_file)).resolve().parent / opts.destdir
+    else:
+        assert opts.destdir.is_absolute(), "Provide `--build-file` to resolve destination directories"
+        basedir = opts.destdir
+    ripunzip = opts.ripunzip and runfiles.Rlocation(opts.ripunzip)
+    with concurrent.futures.ThreadPoolExecutor() as pool:
+        tasks = {}
+        for dir, actions in opts.actions.items():
+            if actions:
+                target = basedir / dir
+                if target.exists() and opts.cleanup:
+                    shutil.rmtree(target)
+                target.mkdir(parents=True, exist_ok=True)
+                tasks.update((pool.submit(t.run), t)
+                             for action in actions
+                             for t in action.tasks(target, ripunzip))
+        while tasks:
+            done, _ = concurrent.futures.wait(tasks, return_when=concurrent.futures.FIRST_COMPLETED)
+            for future in done:
+                future.result()
+                print(tasks.pop(future))
+
+
+if __name__ == '__main__':
+    main()