From e9fa0aac2167551490dd6e713dc22f4f48714ff0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Constantin=20F=C3=BCrst?= <c@fuersten.info>
Date: Mon, 29 Aug 2022 23:29:50 +0200
Subject: [PATCH] enable multithreading support by building a command list and
 iterating over it in parallel with thread amount configurable in ini

---
 libconv.py       | 20 +++++++++++++++++++-
 quality-flac.ini |  1 +
 small-mp3.ini    |  1 +
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/libconv.py b/libconv.py
index 23fcdc9..facb6dc 100644
--- a/libconv.py
+++ b/libconv.py
@@ -7,6 +7,7 @@ import subprocess
 import sys
 import re
 
+from joblib import Parallel, delayed
 from configparser import ConfigParser
 from copy import deepcopy
 from pathlib import Path
@@ -27,12 +28,15 @@ DRY_RUN: bool = config.get("libconv", "dry_run") != "false"
 DEDUCE_METADATA: bool = config.get("libconv", "deduce_metadata") == "true"
 FFMPEG_LOCATION: str = config.get("ffmpeg", "location")
 FFMPEG_OPTS: str = config.get("ffmpeg", "options")
+THREADS: int = int(config.get("libconv", "threads"))
 
 if DST_OVERWRITE:
     FFMPEG_OPTS += " -y"
 
 logging.basicConfig(level=logging.INFO)
 
+cmd_list: List[str] = []
+
 # ----------------------------------------------------------------- #
 # file and folder operations
 
@@ -49,7 +53,7 @@ def mkdir(path: str):
 def execute(command: str):
     logging.debug(f"execute: {command}")
     if not DRY_RUN:
-        os.system(command)
+        cmd_list.append(command)
 
 # ----------------------------------------------------------------- #
 # cue sheet processing
@@ -210,6 +214,18 @@ def process_folder(path: str):
         logging.info("scanning subfolders")
         scan_folder(path)
 
+def execute_command_list():
+    logging.info(f"Executing all {len(cmd_list)} commands with {THREADS} parallel threads")
+
+    if DRY_RUN:
+        logging.info("Skipping execution as we are dry-running. Printing list as debug-info.")
+        logging.debug(str(cmd_list))
+        return
+
+    Parallel(n_jobs=THREADS)(
+        delayed(os.system)(cmd) for cmd in cmd_list
+    )
+
 if __name__ == "__main__":
     logging.info(f"Using settings from {CONFIG_FILE}")
 
@@ -219,3 +235,5 @@ if __name__ == "__main__":
         logging.info("Overwrite of existing files active")
 
     process_folder(SRC_FOLDER)
+    execute_command_list()
+
diff --git a/quality-flac.ini b/quality-flac.ini
index 22127e0..4c831cf 100644
--- a/quality-flac.ini
+++ b/quality-flac.ini
@@ -11,4 +11,5 @@ location = ffmpeg
 [libconv]
 overwrite = false
 dry_run = true
+threads = 6
 
diff --git a/small-mp3.ini b/small-mp3.ini
index 53987c7..4ad4a8e 100644
--- a/small-mp3.ini
+++ b/small-mp3.ini
@@ -12,4 +12,5 @@ location = ffmpeg
 overwrite = true
 dry_run = false
 deduce_metadata = true
+threads = 6