1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
import hashlib
import json
import os.path
import filelock
cache_filename = "cache.json"
cache_data = None
def dump_cache():
with filelock.FileLock(cache_filename+".lock"):
with open(cache_filename, "w", encoding="utf8") as file:
json.dump(cache_data, file, indent=4)
def cache(subsection):
global cache_data
if cache_data is None:
with filelock.FileLock(cache_filename+".lock"):
if not os.path.isfile(cache_filename):
cache_data = {}
else:
with open(cache_filename, "r", encoding="utf8") as file:
cache_data = json.load(file)
s = cache_data.get(subsection, {})
cache_data[subsection] = s
return s
def calculate_sha256(filename):
hash_sha256 = hashlib.sha256()
with open(filename, "rb") as f:
for chunk in iter(lambda: f.read(4096), b""):
hash_sha256.update(chunk)
return hash_sha256.hexdigest()
def sha256(filename, title):
hashes = cache("hashes")
ondisk_mtime = os.path.getmtime(filename)
if title in hashes:
cached_sha256 = hashes[title].get("sha256", None)
cached_mtime = hashes[title].get("mtime", 0)
if ondisk_mtime <= cached_mtime and cached_sha256 is not None:
return cached_sha256
print(f"Calculating sha256 for {filename}: ", end='')
sha256_value = calculate_sha256(filename)
print(f"{sha256_value}")
hashes[title] = {
"mtime": ondisk_mtime,
"sha256": sha256_value,
}
dump_cache()
return sha256_value
|
