From b389cbc3c3f72c3691e5133672d559f13cd39ea1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Carlos=20Cuevas?= <reset.reboot@gmail.com>
Date: Sun, 8 Mar 2020 18:49:22 +0100
Subject: [PATCH] Now with multiprocessing to speed things up

---
 src/processor.py | 41 +++++++++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/processor.py b/src/processor.py
index cdc8108..089b889 100644
--- a/src/processor.py
+++ b/src/processor.py
@@ -2,6 +2,7 @@
 
 import argparse
 import math
+import multiprocessing
 import os
 
 from parser import parse_gpx
@@ -29,6 +30,24 @@ def create_args_parser():
     return parser
 
 
+def draw_frame(data):
+    """
+    For multiprocessing purposes, this takes a dict
+    with the options and the data point and creates
+    a frame
+    """
+    elem = data["datapoint"]
+    max_speed = data["max"]["speed"]
+    stills_path = data["stills"]
+    frame_no = data["frame_no"]
+    ctx = draw.initialize(1920, 1080)
+    draw.set_background(ctx, 0, 0, 0, 0.0)
+    speedometer(ctx, 200, 900, 150, elem[0], max_speed)
+    draw.save_to_file(ctx, os.path.join(stills_path, f"still-{frame_no:08}.png"))
+
+    return True
+
+
 def main(filename, fps, stills_path):
     data = parse_gpx(filename, fps)
     max_speed = data.get_maximum('speed')
@@ -43,15 +62,25 @@ def main(filename, fps, stills_path):
     frame = 0
     last_frame = data.length()
 
+    batch = []
+
+    print("Preparing batch processing")
     for elem in data.get_datapoints():
-        ctx = draw.initialize(1920, 1080)
-        draw.set_background(ctx, 0, 0, 0, 0.0)
-        progress_bar = create_progress_bar(frame, last_frame, 60)
-        print(f"Current Frame: {frame} {progress_bar} {(frame/last_frame) * 100.0:.2f} %", end="\r")
-        speedometer(ctx, 200, 900, 150, elem[0], max_speed)
-        draw.save_to_file(ctx, os.path.join(stills_path, f"still-{frame:08}.png"))
+        batch.append({"frame_no": frame,
+                      "datapoint": elem,
+                      "stills": stills_path,
+                      "max": {"speed": max_speed}})
         frame += 1
 
+    with multiprocessing.Pool() as p:
+        it = p.imap_unordered(draw_frame, batch)
+        count = 0
+
+        for elem in it:
+            count += 1
+            progress_bar = create_progress_bar(count, last_frame, 60)
+            print(f"Current Frame: {count} {progress_bar} {(count/last_frame) * 100.0:.2f} %", end="\r")
+
 
 if __name__ == "__main__":
     parser = create_args_parser()