From 1d74d8d9f631c8ba610f581d59e825252ab16185 Mon Sep 17 00:00:00 2001 From: Jody Bruchon Date: Thu, 17 Sep 2020 17:28:22 -0400 Subject: [PATCH] Try to mitigate the problem of loading a fully sorted archive Sorted archives turn the binary tree into a linked list and make things horribly slow. This is an incomplete mitigation for this issue. --- youtube_dlc/YoutubeDL.py | 45 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) diff --git a/youtube_dlc/YoutubeDL.py b/youtube_dlc/YoutubeDL.py index bae42bf37..6da32960a 100644 --- a/youtube_dlc/YoutubeDL.py +++ b/youtube_dlc/YoutubeDL.py @@ -113,12 +113,14 @@ from .version import __version__ if compat_os_name == 'nt': import ctypes +# Archive tree class ArchiveTree(object): def __init__(self, line): self.left = None self.right = None self.line = line + # Tree insertion def at_insert(self, line): # print("at_insert: ", line) cur = self @@ -130,6 +132,7 @@ class ArchiveTree(object): cur.left = ArchiveTree(line) return else: +# print("LEFT") cur = cur.left continue elif line > cur.line: @@ -137,6 +140,7 @@ class ArchiveTree(object): cur.right = ArchiveTree(line) return else: +# print("RIGHT") cur = cur.right continue else: @@ -410,16 +414,55 @@ class YoutubeDL(object): """Preload the archive, if any is specified""" def preload_download_archive(self): + lines = [] fn = self.params.get('download_archive') if fn is None: return False try: with locked_file(fn, 'r', encoding='utf-8') as archive_file: for line in archive_file: - self.archive.at_insert(line.strip()) + lines.append(line.strip()) except IOError as ioe: if ioe.errno != errno.ENOENT: raise + lmax = len(lines) + if lmax >= 4: + # Populate binary search tree by splitting the archive list in half + # and then adding from the outside edges inward + # This mitigates the worst case where the archive has been sorted + ptrLL = 0 + ptrLR = lmax // 2 + ptrRL = ptrLR + 1 + ptrRR = lmax - 1 + inserted = 0 + while True: +# print("ptrs: %d %d %d %d" % (ptrLL, ptrLR, ptrRL, ptrRR)) + if ptrLR > ptrLL: + self.archive.at_insert(lines[ptrLR]) + inserted += 1 + ptrLR -= 1; + if ptrRL < ptrRR: + self.archive.at_insert(lines[ptrRL]) + inserted += 1 + ptrRL += 1; + if ptrLL < ptrLR: + self.archive.at_insert(lines[ptrLL]) + inserted += 1 + ptrLL += 1; + if ptrRR > ptrRL: + self.archive.at_insert(lines[ptrRR]) + inserted += 1 + ptrRR -= 1; + if ptrLL == ptrLR and ptrRL == ptrRR: + print("inserted: %d, lmax: %d" % (inserted, lmax)) + break + elif lmax > 0: + # Skip multi-line logic for a single line + for idx in lines: + self.archive.at_insert(idx) + else: + # No lines were loaded + return False return True def check_deprecated(param, option, suggestion):