extract_odf_links: Support multiprocessing.

This cuts audit packet manifest build time in half on my 8-core laptop.

conservancy_beancount/tools/audit_report.py

@@ -242,7 +242,7 @@ def main(arglist: Optional[Sequence[str]]=None,
         if not args.force or len(missing_reports) == len(output_reports):
             return os.EX_UNAVAILABLE
 
-    arglist = [f'--delimiter={args.delimiter}']
+    arglist = [f'--delimiter={args.delimiter}', f'--jobs={args.jobs}']
     if repo_path is not None:
         arglist.append(f'--relative-to={repo_path}')
     arglist.extend(str(p) for p in output_reports if p not in missing_reports)

conservancy_beancount/tools/extract_odf_links.py

@@ -20,7 +20,9 @@ filesystem, and writes their full paths to stdout.
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import argparse
+import concurrent.futures as futmod
 import logging
+import multiprocessing
 import os
 import sys
 import urllib.parse
@@ -32,6 +34,8 @@ import odf.opendocument  # type:ignore[import]
 import odf.text  # type:ignore[import]
 
 from typing import (
+    Dict,
+    Hashable,
     Iterator,
     Optional,
     Sequence,
@@ -41,7 +45,11 @@ from typing import (
 
 from .. import cliutil
 
+# This should be Queue[Optional[Path]] but that requires newer typeshed
+PathQ = multiprocessing.SimpleQueue
+
 PROGNAME = 'extract-odf-links'
+_QUEUES: Dict[Hashable, PathQ] = {}
 logger = logging.getLogger('conservancy_beancount.tools.extract_odf_links')
 
 def parse_delimiter(arg: str) -> str:
@@ -58,6 +66,7 @@ def parse_arguments(arglist: Optional[Sequence[str]]=None) -> argparse.Namespace
     parser = argparse.ArgumentParser(prog=PROGNAME)
     cliutil.add_version_argument(parser)
     cliutil.add_loglevel_argument(parser)
+    cliutil.add_jobs_argument(parser)
     parser.add_argument(
         '--delimiter', '-d',
         metavar='TEXT',
@@ -88,8 +97,11 @@ spreadsheet's path
         help="""ODF file(s) to extract links from
 """)
     args = parser.parse_args(arglist)
+    paths_count = len(args.odf_paths)
+    args.odf_paths = [path for path in args.odf_paths if path != cliutil.STDSTREAM_PATH]
+    args.read_stdin = paths_count > len(args.odf_paths)
     if args.relative_to is None:
-        if any(path == cliutil.STDSTREAM_PATH for path in args.odf_paths):
+        if args.read_stdin:
             parser.error("--relative-to is required to read from stdin")
     elif args.relative_to.is_dir() or not args.relative_to.exists():
         args.relative_to /= 'PathStub.ods'
@@ -112,31 +124,68 @@ def extract_links(odf_doc: odf.opendocument.OpenDocument, rel_path: Path) -> Ite
                 continue
         yield path
 
+def enqueue_links(odf_path: Path,
+                  rel_path: Optional[Path],
+                  queue_key: Hashable,
+                  stdin_fd: int,
+) -> None:
+    queue = _QUEUES[queue_key]
+    try:
+        with cliutil.bytes_output(odf_path, stdin_fd, 'r') as odf_file:
+            odf_doc = odf.opendocument.load(odf_file)
+        for path in extract_links(odf_doc, rel_path or odf_path):
+            queue.put(path)
+    finally:
+        queue.put(None)
+
 def main(arglist: Optional[Sequence[str]]=None,
          stdout: TextIO=sys.stdout,
          stderr: TextIO=sys.stderr,
 ) -> int:
     args = parse_arguments(arglist)
     cliutil.set_loglevel(logger, args.loglevel)
+    args.odf_paths.sort(key=lambda path: path.stat().st_size)
+    if not args.read_stdin:
+        # Set a value that passes type checking but will crash if opened.
+        stdin_fd = -1
+    else:
+        # multiprocessing closes subprocesses' stdin.
+        # Migrate it to a new fd they can read.
+        stdin_fd = os.dup(sys.stdin.fileno())
+        os.set_inheritable(stdin_fd, True)
+        args.odf_paths.append(cliutil.STDSTREAM_PATH)
+    args.odf_paths.reverse()
+
+    queue_key = id(args)
+    queue = _QUEUES[queue_key] = multiprocessing.SimpleQueue()
+    # `args.jobs - 1` because the main process does enough work to count as one.
+    max_procs = max(1, min(args.jobs - 1, len(args.odf_paths)))
+    with futmod.ProcessPoolExecutor(max_procs) as pool:
+        procs = {pool.submit(
+            enqueue_links, odf_path, args.relative_to, queue_key, stdin_fd,
+        ) for odf_path in args.odf_paths}
+        procs_left = len(procs)
+        seen: Set[Path] = set()
+        while procs_left:
+            path = queue.get()
+            if path is None:
+                procs_left -= 1
+            elif path not in seen:
+                seen.add(path)
+                if not path.exists():
+                   logger.warning("path %s not found", path)
+                print(path, end=args.delimiter, file=stdout)
 
     returncode = 0
-    links: Set[Path] = set()
-    for odf_path in args.odf_paths:
+    for odf_path, proc in zip(args.odf_paths, procs):
         try:
-            with cliutil.bytes_output(odf_path, sys.stdin, 'r') as odf_file:
-                odf_doc = odf.opendocument.load(odf_file)
-            links.update(extract_links(odf_doc, args.relative_to or odf_path))
+            proc.result()
         except IOError as error:
             logger.error("error reading %s: %s", odf_path, error.strerror)
             returncode = os.EX_DATAERR
         except BadZipFile as error:
             logger.error("error parsing %s: %s", odf_path, error.args[0])
             returncode = os.EX_DATAERR
-
-    for link in links:
-        if not link.exists():
-            logger.warning("path %s not found", link)
-        print(link, end=args.delimiter, file=stdout)
     return returncode
 
 entry_point = cliutil.make_entry_point(__name__, PROGNAME)