Commit 4b662ffa authored by louiz’'s avatar louiz’

Much more efficient and clean way to get the last n messages from history

parent 07ab1138
......@@ -6,6 +6,7 @@
# it under the terms of the zlib license. See the COPYING file.
from os import environ, makedirs
import mmap
import os
import re
from datetime import datetime
......@@ -89,7 +90,10 @@ class Logger(object):
def get_logs(self, jid, nb=10):
"""
Get the log history for the given jid
Get the nb last messages from the log history for the given jid.
Note that a message may be more than one line in these files, so
this function is a little bit more complicated than “read the last
nb lines”.
"""
if config.get_by_tabname('load_log', 10, jid) <= 0:
return
......@@ -112,31 +116,27 @@ class Logger(object):
if not fd:
return
pos = fd.seek(0, 2)
reads = 0
check_next = False
while reads < nb:
if pos == 0:
break
pos -= 1
if pos < 0:
pos = 0
fd.seek(pos)
char = fd.read(1)
if char == b'\n':
if fd.read(2) in (b'MR', b'MI'):
reads += 1
fd.seek(-2, 1)
logs = fd.readlines()
fd.close()
lines = []
for line in logs:
lines.append(line.decode(errors='replace')[:-1])
# read the needed data from the file, we just search nb messages by
# searching "\nM" nb times from the end of the file. We use mmap to
# do that efficiently, instead of seek()s and read()s which are costly.
with fd:
m = mmap.mmap(fd.fileno(), 0, prot=mmap.PROT_READ)
pos = m.rfind(b"\nM") # start of messages begin with MI or MR,
# after a \n
# number of message found so far
count = 0
while pos != -1 and count < nb-1:
count += 1
pos = m.rfind(b"\nM", 0, pos)
if pos == -1: # If we don't have enough lines in the file
pos = 1 # 1, because we do -1 just on the next line
# to get 0 (start of the file)
lines = m[pos-1:].decode(errors='replace').split("\n")[:-1]
messages = []
color = '\x19%s}' % dump_tuple(get_theme().COLOR_INFORMATION_TEXT)
# now convert that data into actual Message objects
idx = 0
while idx < len(lines):
if lines[idx].startswith(' '): # should not happen ; skip
......
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