zsh: limit history in memory to 10000 lines

10000 lines should suffice in general, no need to waste additional
memory. Additionally hist_expire_dups_first has been removed, because
this causes a lot of additional CPU load, probably loading $HISTFILE
over and over again.

If further history is required, it can be loaded with a function like
the following:

function hist {
    local TEMPHISTFILE="$HISTFILE"
    local TEMPSIZE=$SAVEHIST
    fc -pa
    HISTSIZE=$TEMPSIZE
    fc -R "$TEMPHISTFILE"
    fc -l 0
}

The problem with the above is that it will increase the memory footprint
of the zsh process, up to ~50MiB, that doesn't seem to be freed later.

Just grepping $HISTFILE produces a similar result, without this
drawback.

1 files changed, 2 insertions, 3 deletions

diff --git a/.zshrc b/.zshrc
index 964c288..8c5c92e 100644
--- a/.zshrc
+++ b/.zshrc
@@ -31,13 +31,12 @@ zle -N bracketed-paste bracketed-paste-magic
 
 ## history
 HISTFILE="$ZSH_HOME/.zsh_history"
-HISTSIZE=100000000
-SAVEHIST=$HISTSIZE
+HISTSIZE=10000
+SAVEHIST=100000000
 setopt extended_history
 setopt hist_ignore_dups
 setopt inc_append_history
 setopt share_history
-setopt hist_expire_dups_first
 
 ## completion
 zmodload zsh/complist