From: Zeshy <ml.zsh@gmx.es>
To: zsh-workers@zsh.org
Subject: [BUG] APPEND_HISTORY leads to complete reread + rewrite of histfile
Date: Wed, 6 Dec 2017 20:31:23 +0100 [thread overview]
Message-ID: <20171206193122.w4r3dhkotlhdtrah@local> (raw)
Hi all!
In search of the reason why zsh (5.4.2 and fairly recent git) is
so much slower reading/writing larger history files (13 MB, 330k lines)
than bash (4.4.12), I think I found a bug. If I missed something (like
some option), and this is not a bug, but just misconfiguration, or if
you need more information, please let me know.
When configured to *append* the history on exit with the following
config:
---------------- BEGIN .zshrc -----------------
#!/usr/bin/zsh
HISTFILE="/var/tmp/.histfile"
HISTSIZE=9223372036854775807 # LONG_MAX (limits.h)
SAVEHIST=9223372036854775807 # LONG_MAX (limits.h)
setopt append_history
setopt extended_history
unsetopt hist_save_by_copy
unsetopt inc_append_history_time
---------------- END .zshrc -----------------
zsh (with "-d" or without) seems to do the following:
Step 1) append to history file
Step 2) read complete history file
Step 3) write complete history file
This seems to be invariant to
- option HIST_SAVE_BY_COPY,
- option INC_APPEND_HISTORY_TIME,
- values of HISTSIZE and SAVEHIST (tried with 500000 for both).
With "unsetopt APPEND_HISTORY", only step 3 is executed, as expected.
I interspersed some debug printf's in Src/hist.c and saved the output
of simply starting zsh and hitting Ctrl-D (exit). Absolute and relative
times are in milliseconds.
URLs:
https://pastebin.com/BzJhrr69 .zshrc-appendhistory
https://pastebin.com/ULCt7XcR .zshrc-noappendhistory
https://pastebin.com/bHTqQu0C hist.c
https://pastebin.com/QUjZ98Zn zsh-appendhistory--debug-output.txt
https://pastebin.com/VUpGf6Fa zsh-noappendhistory--debug-output.txt
Zeshy
next reply other threads:[~2017-12-06 19:36 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-06 19:31 Zeshy [this message]
2017-12-06 19:51 ` Bart Schaefer
2017-12-06 19:52 ` Bart Schaefer
2017-12-21 20:52 ` Zeshy
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