#!/bin/sh
-# Copyright 2018 Paul Hänsch
+# Copyright 2018, 2019, 2021 Paul Hänsch
#
# This is a file format helper, part of CGIlite.
#
[ -n "$include_storage" ] && return 0
include_storage="$0"
+CR="\r"
+BR='
+'
+
LOCK(){
- local lock timeout block
- lock="${1}.lock"
- timeout="${2-20}"
- if [ \! -w "${lock%/*}" ] || [ -e "$lock" -a \! -d "$lock" ]; then
- printf 'Impossible to get lock: %s\n' "$lock" >&2
+ local lock="${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 "$block"; }; then
- printf 'Overriding stale lock: %s\n' "$lock" >&2
- break
- fi
- if [ $timeout -le 0 ]; then
- printf 'Timeout while trying to get lock: %s\n' "$lock" >&2
- 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
- printf 'Cannot remove tainted lock: %s\n' "$lock" >&2
- printf '%i\n' $$ >"${lock}/pid"
- return 1
- fi
+ local lock="${1}.lock" block
+
+ read block <"$lock"
+ if [ "$block" = $$ ]; then
+ rm -- "$lock"
return 0
else
- printf 'Refusing to release foreign lock: %s\n' "$lock" >&2
+ debug "Refusing to release foreign lock: $lock"
return 1
fi
}
-STRING='
- s;\\;\\\\;g;
- s;\n;\\n;g;
- s;\t;\\t;g;
- s;\r;\\r;g;
- s;\+;\\+;g;
- s; ;+;g;
-'
-
STRING(){
- { [ $# -eq 0 ] && cat || printf %s "$*"; } \
- | sed -r ':X; $!{N;bX;}'"$STRING"
+ local in out=''
+ [ $# -gt 0 ] && in="$*" || in="$(cat)"
+ while [ "$in" ]; do case $in in
+ \\*) out="${out}\\\\"; in="${in#\\}" ;;
+ "$BR"*) out="${out}\\n"; in="${in#${BR}}" ;;
+ "$CR"*) out="${out}\\r"; in="${in#${CR}}" ;;
+ " "*) out="${out}\\t"; in="${in# }" ;;
+ +*) out="${out}\\+"; in="${in#+}" ;;
+ " "*) out="${out}+"; in="${in# }" ;;
+ *) out="${out}${in%%[\\${CR}${BR} + ]*}"; in="${in#"${in%%[\\${BR}${CR} + ]*}"}" ;;
+ esac; done
+ printf '%s' "${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(){
- { [ $# -eq 0 ] && cat || printf %s "$*"; } \
- | sed -r "$UNSTRING"
+ local in out=''
+ [ $# -gt 0 ] && in="$*" || in="$(cat)"
+ while [ "$in" ]; do case $in in
+ \\\\*) out="${out}\\"; in="${in#\\\\}" ;;
+ \\n*) out="${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="${in#+}" ;;
+ \\*) in="${in#\\}" ;;
+ *) out="${out}${in%%[\\+]*}"; in="${in#"${in%%[\\+]*}"}" ;;
+ esac; done
+ printf '%s\n' "$out"
+}
+
+DBM() {
+ local file="$1" cmd="$2"
+ local k v key value
+ shift 2;
+
+ case "$cmd" in
+ check|contains)
+ key="$(STRING "$1")"
+ while read -r k v; do if [ "$k" = "$key" ]; then
+ return 0
+ fi; done <"$file" 2>&-
+ return 1
+ ;;
+ get)
+ key="$(STRING "$1")"
+ while read -r k v; do if [ "$k" = "$key" ]; then
+ UNSTRING "$v"
+ return 0
+ fi; done <"$file" 2>&-
+ return 1
+ ;;
+ set|store)
+ key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ { while read -r k v; do
+ [ "$k" = "$key" ] || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ printf '%s\t%s\n' "$key" "$value"
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ add|insert)
+ k="$1" key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ if DBM "$file" check "$k"; then
+ RELEASE "$file"
+ return 1
+ else
+ printf '%s\t%s\n' "$key" "$value" >>"${file}"
+ RELEASE "$file"
+ return 0
+ fi
+ ;;
+ update|replace)
+ k="$1" key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ if ! DBM "$file" check "$k"; then
+ RELEASE "$file"
+ return 1
+ fi
+ { while read -r k v; do
+ [ "$k" = "$key" ] \
+ && printf '%s\t%s\n' "$key" "$value" \
+ || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ append)
+ key="$(STRING "$1")" value="$(STRING "$2")"
+ LOCK "$file" || return 1
+ if ! DBM "$file" check "$1"; then
+ RELEASE "$file"
+ return 1
+ fi
+ { while read -r k v; do
+ [ "$k" = "$key" ] \
+ && printf '%s\t%s\n' "$key" "$v$value" \
+ || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ delete|remove)
+ key="$(STRING "$1")"
+ LOCK "$file" || return 1
+ { while read -r k v; do
+ [ "$k" = "$key" ] || printf '%s\t%s\n' "$k" "$v"
+ done <"$file" 2>&-
+ } >"${file}.$$.tmp"
+ mv "${file}.$$.tmp" "${file}"
+ RELEASE "$file"
+ return 0
+ ;;
+ esac
}
projects / cgilite / blobdiff