ArchiveBox/archivebox/links.py
2019-03-22 21:38:08 -04:00

117 lines
3.5 KiB
Python

"""
In ArchiveBox, a Link represents a single entry that we track in the
json index. All links pass through all archiver functions and the latest,
most up-to-date canonical output for each is stored in "latest".
Link {
timestamp: str, (how we uniquely id links)
url: str,
title: str,
tags: str,
sources: [str],
history: {
pdf: [
{start_ts, end_ts, duration, cmd, pwd, status, output},
...
],
...
},
}
"""
from html import unescape
from collections import OrderedDict
from util import (
merge_links,
check_link_structure,
check_links_structure,
)
def validate_links(links):
check_links_structure(links)
links = archivable_links(links) # remove chrome://, about:, mailto: etc.
links = uniquefied_links(links) # merge/dedupe duplicate timestamps & urls
links = sorted_links(links) # deterministically sort the links based on timstamp, url
if not links:
print('[X] No links found :(')
raise SystemExit(1)
for link in links:
link['title'] = unescape(link['title'].strip()) if link['title'].strip() else None
check_link_structure(link)
return list(links)
def archivable_links(links):
"""remove chrome://, about:// or other schemed links that cant be archived"""
return (
link
for link in links
if any(link['url'].lower().startswith(s) for s in ('http://', 'https://', 'ftp://'))
)
def uniquefied_links(sorted_links):
"""
ensures that all non-duplicate links have monotonically increasing timestamps
"""
unique_urls = OrderedDict()
lower = lambda url: url.lower().strip()
without_www = lambda url: url.replace('://www.', '://', 1)
without_trailing_slash = lambda url: url[:-1] if url[-1] == '/' else url.replace('/?', '?')
for link in sorted_links:
fuzzy_url = without_www(without_trailing_slash(lower(link['url'])))
if fuzzy_url in unique_urls:
# merge with any other links that share the same url
link = merge_links(unique_urls[fuzzy_url], link)
unique_urls[fuzzy_url] = link
unique_timestamps = OrderedDict()
for link in unique_urls.values():
link['timestamp'] = lowest_uniq_timestamp(unique_timestamps, link['timestamp'])
unique_timestamps[link['timestamp']] = link
return unique_timestamps.values()
def sorted_links(links):
sort_func = lambda link: (link['timestamp'].split('.', 1)[0], link['url'])
return sorted(links, key=sort_func, reverse=True)
def links_after_timestamp(links, timestamp=None):
if not timestamp:
yield from links
return
for link in links:
try:
if float(link['timestamp']) <= float(timestamp):
yield link
except (ValueError, TypeError):
print('Resume value and all timestamp values must be valid numbers.')
def lowest_uniq_timestamp(used_timestamps, timestamp):
"""resolve duplicate timestamps by appending a decimal 1234, 1234 -> 1234.1, 1234.2"""
timestamp = timestamp.split('.')[0]
nonce = 0
# first try 152323423 before 152323423.0
if timestamp not in used_timestamps:
return timestamp
new_timestamp = '{}.{}'.format(timestamp, nonce)
while new_timestamp in used_timestamps:
nonce += 1
new_timestamp = '{}.{}'.format(timestamp, nonce)
return new_timestamp