Add multiprocess support in targs

1 files changed, 24 insertions, 7 deletions

diff --git a/patternutils/commands/targs.py b/patternutils/commands/targs.py
index bfacbfc..51f5527 100644
--- a/patternutils/commands/targs.py
+++ b/patternutils/commands/targs.py
@@ -1,11 +1,15 @@
+import functools
 import json
 import multiprocessing
+import os
 import shlex
 import subprocess
 
 from typing import (
     Union,
     List,
+    Dict,
+    Callable,
 )
 
 import click
@@ -13,6 +17,16 @@ import click
 import patternutils
 
 
+def run_command(data: Dict[str, str], render: Callable[..., str], shell: bool=False) -> None:
+    c = render(**data)
+    if not shell:
+        prepared_command = shlex.split(c)
+    else:
+        prepared_command = c
+
+    subprocess.run(prepared_command, shell=shell)
+
+
 @click.command(context_settings={'help_option_names': ('-h', '--help', '-?')})
 @click.option('--read-from', default='-', type=click.File('r'))
 @click.option('-s', '--shell', is_flag=True, default=False,
@@ -21,6 +35,7 @@ import patternutils
               help='select the template engine to use')
 @click.option('-v', '--verbose', is_flag=True, default=False,
               help='explain what is being done')
+@click.option('-P', '--max-procs', default=1, type=click.IntRange(min=0, clamp=True))
 @click.version_option()
 @click.argument('command')
 def targs(
@@ -28,6 +43,7 @@ def targs(
     read_from: click.File,
     shell: bool,
     template_engine: str,
+    max_procs: int,
     verbose: bool,
 ) -> None:
 
@@ -44,14 +60,15 @@ def targs(
         click.secho('jinja2 not installed!', fg='red', err=True)
         raise SystemExit
 
-    for r in data:
-        c = render(**r)
-        if not shell:
-            prepared_command = shlex.split(c)  # type: Union[str, List[str]]
-        else:
-            prepared_command = c
+    max_procs = os.cpu_count() * 2 if max_procs == 0 else max_procs
 
-        subprocess.run(prepared_command, shell=shell)
+    patched_run_command = functools.partial(run_command, render=render, shell=shell)
+    if max_procs == 1:
+        for r in data:
+            patched_run_command(r)
+    else:
+        with multiprocessing.Pool(max_procs) as p:
+            p.map(patched_run_command, data)
 
 
 if __name__ == '__main__':