X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=youtube_dl%2Futils.py;h=8fa4cb67f3c0fd8344ad33e1bc3098d2653cc085;hb=fa7df757a70b40e352735de8189f2aa7f900bc8d;hp=3d29039867efa2b21b005a035c9cbf5c43bb5d71;hpb=50317b111dadccba73bcdd828d9997d1da78a5f1;p=youtube-dl

diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 3d2903986..8fa4cb67f 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -6,6 +6,7 @@ import datetime
 import email.utils
 import errno
 import gzip
+import itertools
 import io
 import json
 import locale
@@ -1164,3 +1165,50 @@ def check_executable(exe, args=[]):
     except OSError:
         return False
     return exe
+
+
+class PagedList(object):
+    def __init__(self, pagefunc, pagesize):
+        self._pagefunc = pagefunc
+        self._pagesize = pagesize
+
+    def __len__(self):
+        # This is only useful for tests
+        return len(self.getslice())
+
+    def getslice(self, start=0, end=None):
+        res = []
+        for pagenum in itertools.count(start // self._pagesize):
+            firstid = pagenum * self._pagesize
+            nextfirstid = pagenum * self._pagesize + self._pagesize
+            if start >= nextfirstid:
+                continue
+
+            page_results = list(self._pagefunc(pagenum))
+
+            startv = (
+                start % self._pagesize
+                if firstid <= start < nextfirstid
+                else 0)
+
+            endv = (
+                ((end - 1) % self._pagesize) + 1
+                if (end is not None and firstid <= end <= nextfirstid)
+                else None)
+
+            if startv != 0 or endv is not None:
+                page_results = page_results[startv:endv]
+            res.extend(page_results)
+
+            # A little optimization - if current page is not "full", ie. does
+            # not contain page_size videos then we can assume that this page
+            # is the last one - there are no more ids on further pages -
+            # i.e. no need to query again.
+            if len(page_results) + startv < self._pagesize:
+                break
+
+            # If we got the whole page, but the next page is not interesting,
+            # break out early as well
+            if end == nextfirstid:
+                break
+        return res