perf(bash-v2): standard completion optimizations (#1683)

Refactor to remove two loops over the entire list of candidates.

Format descriptions only for completions that are actually going to be
displayed, instead of for all candidates.

Format descriptions inline in completions array, removing need for a
command substitution/subshell and a printf escape per displayed
completion.
This commit is contained in:
Ville Skyttä 2022-05-03 04:00:51 +03:00 committed by GitHub
parent 4f0facbcee
commit 09d6ba690f
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23

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@ -177,40 +177,28 @@ __%[1]s_handle_standard_completion_case() {
local tab=$'\t' comp
local longest=0
local compline
# Look for the longest completion so that we can format things nicely
while IFS='' read -r comp; do
while IFS='' read -r compline; do
# Strip any description before checking the length
comp=${comp%%%%$tab*}
comp=${compline%%%%$tab*}
# Only consider the completions that match
comp=$(compgen -W "$comp" -- "$cur")
[[ -z $comp ]] && continue
COMPREPLY+=("$compline")
if ((${#comp}>longest)); then
longest=${#comp}
fi
done < <(printf "%%s\n" "${out}")
local completions=()
while IFS='' read -r comp; do
if [ -z "$comp" ]; then
continue
fi
__%[1]s_debug "Original comp: $comp"
comp="$(__%[1]s_format_comp_descriptions "$comp" "$longest")"
__%[1]s_debug "Final comp: $comp"
completions+=("$comp")
done < <(printf "%%s\n" "${out}")
while IFS='' read -r comp; do
COMPREPLY+=("$comp")
done < <(compgen -W "${completions[*]}" -- "$cur")
# 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]%%%% *}"
comp="${COMPREPLY[0]%%%%$tab*}"
__%[1]s_debug "Removed description from single completion, which is now: ${comp}"
COMPREPLY=()
COMPREPLY+=("$comp")
COMPREPLY[0]=$comp
else # Format the descriptions
__%[1]s_format_comp_descriptions $longest
fi
}
@ -230,43 +218,47 @@ __%[1]s_handle_special_char()
__%[1]s_format_comp_descriptions()
{
local tab=$'\t'
local comp="$1"
local longest=$2
local comp desc maxdesclength
local longest=$1
# Properly format the description string which follows a tab character if there is one
if [[ "$comp" == *$tab* ]]; then
desc=${comp#*$tab}
comp=${comp%%%%$tab*}
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 ))
# $COLUMNS stores the current shell width.
# Remove an extra 4 because we add 2 spaces and 2 parentheses.
maxdesclength=$(( 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+="…"
# 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 - ${#comp} - 4 ))
fi
comp+=" ($desc)"
fi
fi
# Must use printf to escape all special characters
printf "%%q" "${comp}"
# 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()