stop on busy system.

Might break multi-processing on same machine. Might fix later.

bin/vcmp

@@ -8,11 +8,32 @@ import argparse
 import tempfile
 import logging
 import time
+import psutil
 
 video_extensions: list[str] = ["mp4", "mkv", "avi", "wmv", "mov", "m4v", "ts", "flv", "mpg"]
 
 total_files: int = 0
 
+def is_system_busy() -> bool:
+    """Returns true if the cpu is doing something else. maybe."""
+    total_cpu = 0
+    our_pids = [os.getpid()]
+    try:
+        # add child processes
+        our_pids.extend(p.pid for p in psutil.Process().children(recursive=True))
+    except:
+        pass
+
+    for proc in psutil.process_iter(['cpu_percent', 'pid']):
+        if proc.info['pid'] not in our_pids:
+            total_cpu += proc.info['cpu_percent']
+    #print(total_cpu)
+
+    cpu_count = psutil.cpu_count()
+    if cpu_count is None:
+        cpu_count = 1
+    return total_cpu > 50 * cpu_count  # TODO: Parameter
+
 def acquire_file_lock(filepath: pathlib.Path) -> bool:
     lock_file = filepath.with_suffix(filepath.suffix + '.lock')
     try:
@@ -105,7 +126,7 @@ def get_video_duration(input_file: pathlib.Path) -> float:
         logging.error(f"Error getting duration for {input_file}")
         return 1.0
 
-def run_progress(process, duration, file_index=0):
+def run_progress(process, duration, file_index=0) -> bool:
     current_time = None
     last_update = 0
     progress = 0
@@ -128,6 +149,8 @@ def run_progress(process, duration, file_index=0):
                 elapsed = time.time() - start_time
                 speed = current_time / elapsed if elapsed > 0 else 0
                 if time.time() - last_update > UPDATE_INTERVAL:
+                    if is_system_busy():
+                        return False
                     total_progress = (file_index / total_files) * 100
                     sys.stdout.write(
                         f"\rProcessing ({file_index}/{total_files} [{total_progress:.1f}%]) :"
@@ -140,6 +163,7 @@ def run_progress(process, duration, file_index=0):
                     last_update = time.time()
             except:
                 pass
+    return True
 
 def run(filepath: pathlib.Path, cmd: list[str], temp_path: pathlib.Path, file_index: int) -> None:
     duration = get_video_duration(filepath)
@@ -154,7 +178,12 @@ def run(filepath: pathlib.Path, cmd: list[str], temp_path: pathlib.Path, file_in
             stderr=log_file,
             universal_newlines=True
         )
-        run_progress(process, duration, file_index)
+        if not run_progress(process, duration, file_index):
+            process.kill()
+            release_file_lock(filepath)
+            if temp_path.exists():
+                temp_path.unlink()
+            sys.exit(0)
         sys.stdout.write("\n")
         sys.stdout.flush()
 
@@ -165,6 +194,7 @@ def run(filepath: pathlib.Path, cmd: list[str], temp_path: pathlib.Path, file_in
             logging.error(f"FFmpeg exited with code {process.returncode}")
             if temp_path.exists():
                 temp_path.unlink()
+            release_file_lock(filepath)
             raise subprocess.CalledProcessError(process.returncode, cmd)
 
 def process_single_file(