#!/bin/sh
-# Copyright 2018, 2019 Paul Hänsch
+# Copyright 2018, 2019, 2021 Paul Hänsch
#
# This is a file format helper, part of CGIlite.
#
'
LOCK(){
- local lock timeout block
- lock="${1}.lock"
- timeout="${2-20}"
- if [ \! -w "${lock%/*}" ] || [ -e "$lock" -a \! -d "$lock" ]; then
+ local lock="${1}.lock" timeout="${2-20}" block
+
+ if [ \! -w "${lock%/*}" ] || [ -e "$lock" -a \! -f "$lock" ]; then
debug "Impossible to get lock: $lock"
return 1
fi
- while ! mkdir "$lock" 2>&-; do
- block="$(cat "$lock/pid" || printf 1)"
- if ! { ps -eo pid |grep -qwF "$block"; }; then
- debug "Overriding stale lock: $lock"
- break
- fi
- if [ $timeout -le 0 ]; then
- debug "Timeout while trying to get lock: $lock"
- return 1
+ while [ $timeout -gt 0 ]; do
+ printf '%i\n' $$ >>"${lock}"
+ read block <"$lock"
+ if [ "$block" = $$ ]; then
+ return 0
+ elif ! { ps -eo pid |grep -qwF "$block"; }; then
+ debug "Trying to override stale lock: $lock"
+ if LOCK "$lock" 1; then
+ rm -- "$lock"
+ RELEASE "$lock"
+ fi
+ else
+ timeout=$((timeout - 1))
+ [ $timeout -gt 0 ] && sleep 1
fi
- timeout=$((timeout - 1))
- sleep 1
done
- printf '%i\n' $$ >"${lock}/pid"
- return 0
+
+ debug "Timeout while trying to get lock: $lock"
+ return 1
}
RELEASE(){
- local lock
- lock="${1}.lock"
- if [ "$(cat "$lock/pid")" = "$$" ]; then
- rm "$lock/pid"
- if ! rmdir "$lock"; then
- debug "Cannot remove tainted lock: $lock"
- printf '%i\n' $$ >"${lock}/pid"
- return 1
- fi
+ local lock="${1}.lock" block
+
+ read block <"$lock"
+ if [ "$block" = $$ ]; then
+ rm -- "$lock"
return 0
else
debug "Refusing to release foreign lock: $lock"
fi
}
-STRING='
- s;\\;\\\\;g;
- s;\n;\\n;g;
- s;\t;\\t;g;
- s;\r;\\r;g;
- s;\+;\\+;g;
- s; ;+;g;
-'
-
-STRING_OLD(){
- { [ $# -eq 0 ] && cat || printf %s "$*"; } \
- | sed -E ':X; $!{N;bX;}'"$STRING"
-}
-
STRING(){
local in out=''
[ $# -gt 0 ] && in="$*" || in="$(cat)"
" "*) out="${out}+"; in="${in# }" ;;
*) out="${out}${in%%[\\${CR}${BR} + ]*}"; in="${in#"${in%%[\\${BR}${CR} + ]*}"}" ;;
esac; done
- printf '%s' "$out"
+ printf '%s' "${out:-\\}"
}
-
-UNSTRING='
- :UNSTRING_X
- s;((^|[^\\])(\\\\)*)\\n;\1\n;g;
- s;((^|[^\\])(\\\\)*)\\t;\1\t;g;
- s;((^|[^\\])(\\\\)*)\\r;\1\r;g;
- s;((^|[^\\])(\\\\)*)\+;\1 ;g;
- tUNSTRING_X;
- s;((^|[^\\])(\\\\)*)\\\+;\1+;g;
- s;\\\\;\\;g;
-'
-UNSTRING_OLD(){
- { [ $# -eq 0 ] && cat || printf %s "$*"; } \
- | sed -E "$UNSTRING"
-}
UNSTRING(){
local in out=''
[ $# -gt 0 ] && in="$*" || in="$(cat)"
\\n*) out="${out}${BR}"; in="${in#\\n}" ;;
\\r*) out="${out}${CR}"; in="${in#\\r}" ;;
\\t*) out="${out} "; in="${in#\\t}" ;;
- \\+) out="${out}+"; in="${in#\\+}" ;;
+ \\+*) out="${out}+"; in="${in#\\+}" ;;
+*) out="${out} "; in="${in#+}" ;;
\\*) in="${in#\\}" ;;
*) out="${out}${in%%[\\+]*}"; in="${in#"${in%%[\\+]*}"}" ;;
esac; done
- printf '%s' "$out"
+ printf '%s\n' "$out"
}
DBM() {
update|replace)
k="$1" key="$(STRING "$1")" value="$(STRING "$2")"
LOCK "$file" || return 1
- if ! DBM check "$k"; then
+ if ! DBM "$file" check "$k"; then
RELEASE "$file"
return 1
fi
append)
key="$(STRING "$1")" value="$(STRING "$2")"
LOCK "$file" || return 1
- if ! DBM check "$1"; then
+ if ! DBM "$file" check "$1"; then
RELEASE "$file"
return 1
fi