[reactor] add wait-min & -max options (#148)

docs/configuration.rst

@@ -583,6 +583,16 @@ Description Download Pixiv's Ugoira animations or ignore them.
 =========== =====
 
 
+extractor.reactor.wait-min & .wait-max
+--------------------------------------
+=========== =====
+Type        ``float``
+Default     ``3.0`` and ``6.0``
+Description Minimum and maximum wait time in seconds between HTTP requests
+            during the extraction process.
+=========== =====
+
+
 extractor.recursive.blacklist
 -----------------------------
 =========== =====

gallery_dl/extractor/reactor.py

@@ -11,6 +11,8 @@
 from .common import SharedConfigExtractor, Message
 from .. import text
 import urllib.parse
+import random
+import time
 import json
 
 
@@ -30,6 +32,11 @@ class ReactorExtractor(SharedConfigExtractor):
         self.root = "http://" + match.group(1)
         self.session.headers["Referer"] = self.root
 
+        self.wait_min = self.config("wait-min", 3)
+        self.wait_max = self.config("wait-max", 6)
+        if self.wait_max < self.wait_min:
+            self.wait_max = self.wait_min
+
         if not self.category:
             # set category based on domain name
             netloc = urllib.parse.urlsplit(self.root).netloc
@@ -55,6 +62,7 @@ class ReactorExtractor(SharedConfigExtractor):
 
     def _pagination(self, url):
         while True:
+            time.sleep(random.uniform(self.wait_min, self.wait_max))
             page = self.request(url).text
 
             yield from text.extract_iter(