From a1dea6ae43f5a1f5e5dfabac49766bda67983ea0 Mon Sep 17 00:00:00 2001
From: Sorin Ionescu <sorin.ionescu@gmail.com>
Date: Sun, 22 Feb 2015 19:51:09 -0500
Subject: [PATCH] Get Git status asynchronously

---
 modules/prompt/functions/prompt_sorin_setup | 50 ++++++++++++++++++---
 1 file changed, 43 insertions(+), 7 deletions(-)

diff --git a/modules/prompt/functions/prompt_sorin_setup b/modules/prompt/functions/prompt_sorin_setup
index 508dc80d..e27f7384 100644
--- a/modules/prompt/functions/prompt_sorin_setup
+++ b/modules/prompt/functions/prompt_sorin_setup
@@ -22,6 +22,33 @@ function prompt_sorin_pwd {
   fi
 }
 
+function prompt_sorin_git_info {
+  # Append Git status.
+  if [[ -s "$_prompt_sorin_precmd_async_data" ]]; then
+    alias typeset='typeset -g'
+    source "$_prompt_sorin_precmd_async_data"
+    RPROMPT+='${git_info:+${(e)git_info[status]}}'
+    unalias typeset
+  fi
+
+  # Reset PID.
+  _prompt_sorin_precmd_async_pid=0
+
+  # Redisplay prompt.
+  zle && zle reset-prompt
+}
+
+function prompt_sorin_precmd_async {
+  # Get Git repository information.
+  if (( $+functions[git-info] )); then
+    git-info
+    typeset -p git_info >! "$_prompt_sorin_precmd_async_data"
+  fi
+
+  # Signal completion to parent process.
+  kill -USR1 $$
+}
+
 function prompt_sorin_precmd {
   setopt LOCAL_OPTIONS
   unsetopt XTRACE KSH_ARRAYS
@@ -29,16 +56,26 @@ function prompt_sorin_precmd {
   # Format PWD.
   prompt_sorin_pwd
 
-  # Get Git repository information.
-  if (( $+functions[git-info] )); then
-    git-info
+  # Define prompts.
+  RPROMPT='${editor_info[overwrite]}%(?:: %F{red}⏎%f)${VIM:+" %B%F{green}V%f%b"}${INSIDE_EMACS:+" %B%F{green}E%f%b"}%f'
+
+  # Kill the old process of slow commands if it is still running.
+  if (( _prompt_sorin_precmd_async_pid > 0 )); then
+    kill -TERM "$_prompt_sorin_precmd_async_pid" &>/dev/null
   fi
+
+  # Compute slow commands in the background.
+  trap prompt_sorin_git_info USR1
+  prompt_sorin_precmd_async &!
+  _prompt_sorin_precmd_async_pid=$!
 }
 
 function prompt_sorin_setup {
   setopt LOCAL_OPTIONS
   unsetopt XTRACE KSH_ARRAYS
   prompt_opts=(cr percent subst)
+  _prompt_sorin_precmd_async_pid=0
+  _prompt_sorin_precmd_async_data="${TMPPREFIX}-prompt_sorin_data"
 
   # Load required functions.
   autoload -Uz add-zsh-hook
@@ -68,12 +105,11 @@ function prompt_sorin_setup {
   zstyle ':prezto:module:git:info:unmerged' format ' %%B%F{yellow}═%f%%b'
   zstyle ':prezto:module:git:info:untracked' format ' %%B%F{white}◼%f%%b'
   zstyle ':prezto:module:git:info:keys' format \
-    'prompt' ' %F{blue}git%f$(coalesce "%b" "%p" "%c")%s' \
-    'rprompt' '%A%B%S%a%d%m%r%U%u'
+    'status' ' %F{blue}git%f$(coalesce "%b" "%p" "%c")%s%A%B%S%a%d%m%r%U%u'
 
   # Define prompts.
-  PROMPT='${SSH_TTY:+"%F{red}%n%f@%F{yellow}%m%f "}%F{cyan}${_prompt_sorin_pwd}%f${git_info:+${(e)git_info[prompt]}}%(!. %B%F{red}#%f%b.)${editor_info[keymap]} '
-  RPROMPT='${editor_info[overwrite]}%(?:: %F{red}⏎%f)${VIM:+" %B%F{green}V%f%b"}${INSIDE_EMACS:+" %B%F{green}E%f%b"}${git_info[rprompt]}'
+  PROMPT='${SSH_TTY:+"%F{red}%n%f@%F{yellow}%m%f "}%F{cyan}${_prompt_sorin_pwd}%(!. %B%F{red}#%f%b.)${editor_info[keymap]} '
+  RPROMPT=''
   SPROMPT='zsh: correct %F{red}%R%f to %F{green}%r%f [nyae]? '
 }