agnoster: cut down on fork/execs improve performance when not in a repo (#6210)

* agnoster: improve perf with use of $jobstates (zsh/parameter module) This saves multiple fork/execs (for the subshell and wc) each time the prompt is rendered * agnoster: compute git repo_path only when in a git repo this avoids needlessly invoking git twice every time we render the prompt * agnoster: avoid subshell when rendering prompt Rather than forking a subshell to print the prompt, construct it incrementally by appending to $PROMPT. v2: fix incorrect CURRENT_BG v3: fix bzr and hg prompting Thanks @mcornella for the help.

agnoster: cut down on fork/execs improve performance when not in a repo (#6210)
fbcda4d5 · Andrew Baumann · Marc Cornellà · 3dab7e46 · fbcda4d5
Commit fbcda4d5 authored May 17, 2018 by Andrew Baumann Committed by Marc Cornellà May 17, 2018
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Showing with 25 additions and 21 deletions

agnoster.zsh-theme themes/agnoster.zsh-theme +25 -21

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--- a/themes/agnoster.zsh-theme
+++ b/themes/agnoster.zsh-theme
@@ -29,6 +29,7 @@
 # A few utility functions to make it easy and re-usable to draw segmented prompts

 CURRENT_BG='NONE'
+zmodload zsh/parameter

 # Special Powerline characters

@@ -55,23 +56,23 @@ prompt_segment() {
  [[ -n $1 ]] && bg="%K{$1}" || bg="%k"
  [[ -n $2 ]] && fg="%F{$2}" || fg="%f"
  if [[ $CURRENT_BG != 'NONE' && $1 != $CURRENT_BG ]]; then
-    echo -n " %{$bg%F{$CURRENT_BG}%}$SEGMENT_SEPARATOR%{$fg%} "
+    PROMPT+=" %{$bg%F{$CURRENT_BG}%}$SEGMENT_SEPARATOR%{$fg%} "
  else
-    echo -n "%{$bg%}%{$fg%} "
+    PROMPT+="%{$bg%}%{$fg%} "
  fi
  CURRENT_BG=$1
-  [[ -n $3 ]] && echo -n $3
+  [[ -n $3 ]] && PROMPT+=$3
 }

 # End the prompt, closing any open segments
 prompt_end() {
  if [[ -n $CURRENT_BG ]]; then
-    echo -n " %{%k%F{$CURRENT_BG}%}$SEGMENT_SEPARATOR"
+    PROMPT+=" %{%k%F{$CURRENT_BG}%}$SEGMENT_SEPARATOR"
  else
-    echo -n "%{%k%}"
+    PROMPT+="%{%k%}"
  fi
-  echo -n "%{%f%}"
-  CURRENT_BG=''
+  PROMPT+="%{%f%}"
+  CURRENT_BG='NONE'
 }

 ### Prompt components
@@ -93,9 +94,9 @@ prompt_git() {
    PL_BRANCH_CHAR=$'\ue0a0'         # 
  }
  local ref dirty mode repo_path
-  repo_path=$(git rev-parse --git-dir 2>/dev/null)

  if $(git rev-parse --is-inside-work-tree >/dev/null 2>&1); then
+    repo_path=$(git rev-parse --git-dir 2>/dev/null)
    dirty=$(parse_git_dirty)
    ref=$(git symbolic-ref HEAD 2> /dev/null) || ref="➦ $(git rev-parse --short HEAD 2> /dev/null)"
    if [[ -n $dirty ]]; then
@@ -123,7 +124,7 @@ prompt_git() {
    zstyle ':vcs_info:*' formats ' %u%c'
    zstyle ':vcs_info:*' actionformats ' %u%c'
    vcs_info
-    echo -n "${ref/refs\/heads\//$PL_BRANCH_CHAR }${vcs_info_msg_0_%% }${mode}"
+    PROMPT+="${ref/refs\/heads\//$PL_BRANCH_CHAR }${vcs_info_msg_0_%% }${mode}"
  fi
 }

@@ -135,15 +136,15 @@ prompt_bzr() {
        revision=`bzr log | head -n2 | tail -n1 | sed 's/^revno: //'`
        if [[ $status_mod -gt 0 ]] ; then
            prompt_segment yellow black
-            echo -n "bzr@"$revision "✚ "
+            PROMPT+="bzr@$revision ✚ "
        else
            if [[ $status_all -gt 0 ]] ; then
                prompt_segment yellow black
-                echo -n "bzr@"$revision
+                PROMPT+="bzr@$revision"

            else
                prompt_segment green black
-                echo -n "bzr@"$revision
+                PROMPT+="bzr@$revision"
            fi
        fi
    fi
@@ -151,36 +152,36 @@ prompt_bzr() {

 prompt_hg() {
  (( $+commands[hg] )) || return
-  local rev status
+  local rev st branch
  if $(hg id >/dev/null 2>&1); then
    if $(hg prompt >/dev/null 2>&1); then
      if [[ $(hg prompt "{status|unknown}") = "?" ]]; then
        # if files are not added
        prompt_segment red white
-        st='±'
+        st=' ±'
      elif [[ -n $(hg prompt "{status|modified}") ]]; then
        # if any modification
        prompt_segment yellow black
-        st='±'
+        st=' ±'
      else
        # if working copy is clean
        prompt_segment green black
      fi
-      echo -n $(hg prompt "☿ {rev}@{branch}") $st
+      PROMPT+="$(hg prompt "☿ {rev}@{branch}")$st"
    else
      st=""
      rev=$(hg id -n 2>/dev/null | sed 's/[^-0-9]//g')
      branch=$(hg id -b 2>/dev/null)
      if `hg st | grep -q "^\?"`; then
        prompt_segment red black
-        st='±'
+        st=' ±'
      elif `hg st | grep -q "^[MA]"`; then
        prompt_segment yellow black
-        st='±'
+        st=' ±'
      else
        prompt_segment green black
      fi
-      echo -n "☿ $rev@$branch" $st
+      PROMPT+="☿ $rev@$branch$st"
    fi
  fi
 }
@@ -207,7 +208,7 @@ prompt_status() {
  symbols=()
  [[ $RETVAL -ne 0 ]] && symbols+="%{%F{red}%}✘"
  [[ $UID -eq 0 ]] && symbols+="%{%F{yellow}%}⚡"
-  [[ $(jobs -l | wc -l) -gt 0 ]] && symbols+="%{%F{cyan}%}⚙"
+  [[ ${#jobstates} -ne 0 ]] && symbols+="%{%F{cyan}%}⚙"

  [[ -n "$symbols" ]] && prompt_segment black default "$symbols"
 }
@@ -215,6 +216,7 @@ prompt_status() {
 ## Main prompt
 build_prompt() {
  RETVAL=$?
+  PROMPT='%{%f%b%k%}'
  prompt_status
  prompt_virtualenv
  prompt_context
@@ -223,6 +225,8 @@ build_prompt() {
  prompt_bzr
  prompt_hg
  prompt_end
+  PROMPT+=' '
 }

-PROMPT='%{%f%b%k%}$(build_prompt) '
+autoload -U add-zsh-hook
+add-zsh-hook precmd build_prompt