spf13--cobra/bash_completionsV2.go
Ville Skyttä 5b11656e45
perf(bash-v2): read directly to COMPREPLY on descriptionless short circuit (#1700)
Not that it'd really matter that much performancewise given the level we
are at for this case, but this change makes the short circuit roughly
twice as fast on my box as it was for the 1000 rounds done in
marckhouzam/cobra-completion-testing.

Perhaps more importantly, this makes the code arguably slightly cleaner.
2022-05-17 20:57:08 -04:00

326 lines
11 KiB
Go

package cobra
import (
"bytes"
"fmt"
"io"
"os"
)
func (c *Command) genBashCompletion(w io.Writer, includeDesc bool) error {
buf := new(bytes.Buffer)
genBashComp(buf, c.Name(), includeDesc)
_, err := buf.WriteTo(w)
return err
}
func genBashComp(buf io.StringWriter, name string, includeDesc bool) {
compCmd := ShellCompRequestCmd
if !includeDesc {
compCmd = ShellCompNoDescRequestCmd
}
WriteStringAndCheck(buf, fmt.Sprintf(`# bash completion V2 for %-36[1]s -*- shell-script -*-
__%[1]s_debug()
{
if [[ -n ${BASH_COMP_DEBUG_FILE:-} ]]; then
echo "$*" >> "${BASH_COMP_DEBUG_FILE}"
fi
}
# Macs have bash3 for which the bash-completion package doesn't include
# _init_completion. This is a minimal version of that function.
__%[1]s_init_completion()
{
COMPREPLY=()
_get_comp_words_by_ref "$@" cur prev words cword
}
# This function calls the %[1]s program to obtain the completion
# results and the directive. It fills the 'out' and 'directive' vars.
__%[1]s_get_completion_results() {
local requestComp lastParam lastChar args
# Prepare the command to request completions for the program.
# Calling ${words[0]} instead of directly %[1]s allows to handle aliases
args=("${words[@]:1}")
requestComp="${words[0]} %[2]s ${args[*]}"
lastParam=${words[$((${#words[@]}-1))]}
lastChar=${lastParam:$((${#lastParam}-1)):1}
__%[1]s_debug "lastParam ${lastParam}, lastChar ${lastChar}"
if [ -z "${cur}" ] && [ "${lastChar}" != "=" ]; then
# If the last parameter is complete (there is a space following it)
# We add an extra empty parameter so we can indicate this to the go method.
__%[1]s_debug "Adding extra empty parameter"
requestComp="${requestComp} ''"
fi
# When completing a flag with an = (e.g., %[1]s -n=<TAB>)
# bash focuses on the part after the =, so we need to remove
# the flag part from $cur
if [[ "${cur}" == -*=* ]]; then
cur="${cur#*=}"
fi
__%[1]s_debug "Calling ${requestComp}"
# Use eval to handle any environment variables and such
out=$(eval "${requestComp}" 2>/dev/null)
# Extract the directive integer at the very end of the output following a colon (:)
directive=${out##*:}
# Remove the directive
out=${out%%:*}
if [ "${directive}" = "${out}" ]; then
# There is not directive specified
directive=0
fi
__%[1]s_debug "The completion directive is: ${directive}"
__%[1]s_debug "The completions are: ${out}"
}
__%[1]s_process_completion_results() {
local shellCompDirectiveError=%[3]d
local shellCompDirectiveNoSpace=%[4]d
local shellCompDirectiveNoFileComp=%[5]d
local shellCompDirectiveFilterFileExt=%[6]d
local shellCompDirectiveFilterDirs=%[7]d
if [ $((directive & shellCompDirectiveError)) -ne 0 ]; then
# Error code. No completion.
__%[1]s_debug "Received error from custom completion go code"
return
else
if [ $((directive & shellCompDirectiveNoSpace)) -ne 0 ]; then
if [[ $(type -t compopt) = "builtin" ]]; then
__%[1]s_debug "Activating no space"
compopt -o nospace
else
__%[1]s_debug "No space directive not supported in this version of bash"
fi
fi
if [ $((directive & shellCompDirectiveNoFileComp)) -ne 0 ]; then
if [[ $(type -t compopt) = "builtin" ]]; then
__%[1]s_debug "Activating no file completion"
compopt +o default
else
__%[1]s_debug "No file completion directive not supported in this version of bash"
fi
fi
fi
if [ $((directive & shellCompDirectiveFilterFileExt)) -ne 0 ]; then
# File extension filtering
local fullFilter filter filteringCmd
# Do not use quotes around the $out variable or else newline
# characters will be kept.
for filter in ${out}; do
fullFilter+="$filter|"
done
filteringCmd="_filedir $fullFilter"
__%[1]s_debug "File filtering command: $filteringCmd"
$filteringCmd
elif [ $((directive & shellCompDirectiveFilterDirs)) -ne 0 ]; then
# File completion for directories only
# Use printf to strip any trailing newline
local subdir
subdir=$(printf "%%s" "${out}")
if [ -n "$subdir" ]; then
__%[1]s_debug "Listing directories in $subdir"
pushd "$subdir" >/dev/null 2>&1 && _filedir -d && popd >/dev/null 2>&1 || return
else
__%[1]s_debug "Listing directories in ."
_filedir -d
fi
else
__%[1]s_handle_completion_types
fi
__%[1]s_handle_special_char "$cur" :
__%[1]s_handle_special_char "$cur" =
}
__%[1]s_handle_completion_types() {
__%[1]s_debug "__%[1]s_handle_completion_types: COMP_TYPE is $COMP_TYPE"
case $COMP_TYPE in
37|42)
# Type: menu-complete/menu-complete-backward and insert-completions
# If the user requested inserting one completion at a time, or all
# completions at once on the command-line we must remove the descriptions.
# https://github.com/spf13/cobra/issues/1508
local tab=$'\t' comp
while IFS='' read -r comp; do
[[ -z $comp ]] && continue
# Strip any description
comp=${comp%%%%$tab*}
# Only consider the completions that match
if [[ $comp == "$cur"* ]]; then
COMPREPLY+=("$comp")
fi
done < <(printf "%%s\n" "${out}")
;;
*)
# Type: complete (normal completion)
__%[1]s_handle_standard_completion_case
;;
esac
}
__%[1]s_handle_standard_completion_case() {
local tab=$'\t' comp
# Short circuit to optimize if we don't have descriptions
if [[ $out != *$tab* ]]; then
IFS=$'\n' read -ra COMPREPLY -d '' < <(IFS=$'\n' compgen -W "$out" -- "$cur")
return 0
fi
local longest=0
local compline
# Look for the longest completion so that we can format things nicely
while IFS='' read -r compline; do
[[ -z $compline ]] && continue
# Strip any description before checking the length
comp=${compline%%%%$tab*}
# Only consider the completions that match
[[ $comp == "$cur"* ]] || continue
COMPREPLY+=("$compline")
if ((${#comp}>longest)); then
longest=${#comp}
fi
done < <(printf "%%s\n" "${out}")
# If there is a single completion left, remove the description text
if [ ${#COMPREPLY[*]} -eq 1 ]; then
__%[1]s_debug "COMPREPLY[0]: ${COMPREPLY[0]}"
comp="${COMPREPLY[0]%%%%$tab*}"
__%[1]s_debug "Removed description from single completion, which is now: ${comp}"
COMPREPLY[0]=$comp
else # Format the descriptions
__%[1]s_format_comp_descriptions $longest
fi
}
__%[1]s_handle_special_char()
{
local comp="$1"
local char=$2
if [[ "$comp" == *${char}* && "$COMP_WORDBREAKS" == *${char}* ]]; then
local word=${comp%%"${comp##*${char}}"}
local idx=${#COMPREPLY[*]}
while [[ $((--idx)) -ge 0 ]]; do
COMPREPLY[$idx]=${COMPREPLY[$idx]#"$word"}
done
fi
}
__%[1]s_format_comp_descriptions()
{
local tab=$'\t'
local comp desc maxdesclength
local longest=$1
local i ci
for ci in ${!COMPREPLY[*]}; do
comp=${COMPREPLY[ci]}
# Properly format the description string which follows a tab character if there is one
if [[ "$comp" == *$tab* ]]; then
__%[1]s_debug "Original comp: $comp"
desc=${comp#*$tab}
comp=${comp%%%%$tab*}
# $COLUMNS stores the current shell width.
# Remove an extra 4 because we add 2 spaces and 2 parentheses.
maxdesclength=$(( COLUMNS - longest - 4 ))
# Make sure we can fit a description of at least 8 characters
# if we are to align the descriptions.
if [[ $maxdesclength -gt 8 ]]; then
# Add the proper number of spaces to align the descriptions
for ((i = ${#comp} ; i < longest ; i++)); do
comp+=" "
done
else
# Don't pad the descriptions so we can fit more text after the completion
maxdesclength=$(( COLUMNS - ${#comp} - 4 ))
fi
# If there is enough space for any description text,
# truncate the descriptions that are too long for the shell width
if [ $maxdesclength -gt 0 ]; then
if [ ${#desc} -gt $maxdesclength ]; then
desc=${desc:0:$(( maxdesclength - 1 ))}
desc+="…"
fi
comp+=" ($desc)"
fi
COMPREPLY[ci]=$comp
__%[1]s_debug "Final comp: $comp"
fi
done
}
__start_%[1]s()
{
local cur prev words cword split
COMPREPLY=()
# Call _init_completion from the bash-completion package
# to prepare the arguments properly
if declare -F _init_completion >/dev/null 2>&1; then
_init_completion -n "=:" || return
else
__%[1]s_init_completion -n "=:" || return
fi
__%[1]s_debug
__%[1]s_debug "========= starting completion logic =========="
__%[1]s_debug "cur is ${cur}, words[*] is ${words[*]}, #words[@] is ${#words[@]}, cword is $cword"
# The user could have moved the cursor backwards on the command-line.
# We need to trigger completion from the $cword location, so we need
# to truncate the command-line ($words) up to the $cword location.
words=("${words[@]:0:$cword+1}")
__%[1]s_debug "Truncated words[*]: ${words[*]},"
local out directive
__%[1]s_get_completion_results
__%[1]s_process_completion_results
}
if [[ $(type -t compopt) = "builtin" ]]; then
complete -o default -F __start_%[1]s %[1]s
else
complete -o default -o nospace -F __start_%[1]s %[1]s
fi
# ex: ts=4 sw=4 et filetype=sh
`, name, compCmd,
ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs))
}
// GenBashCompletionFileV2 generates Bash completion version 2.
func (c *Command) GenBashCompletionFileV2(filename string, includeDesc bool) error {
outFile, err := os.Create(filename)
if err != nil {
return err
}
defer outFile.Close()
return c.GenBashCompletionV2(outFile, includeDesc)
}
// GenBashCompletionV2 generates Bash completion file version 2
// and writes it to the passed writer.
func (c *Command) GenBashCompletionV2(w io.Writer, includeDesc bool) error {
return c.genBashCompletion(w, includeDesc)
}