table style

[cgilite] / storage.sh

diff --git a/storage.sh b/storage.sh
index 61eec88fb2cee63f706a634eaa48c85a09ef1967..22e6accbcba7cddd75bbaec0235a174b4aa53bd3 100755 (executable)
--- a/storage.sh
+++ b/storage.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright 2018, 2019 Paul Hänsch
+# Copyright 2018, 2019, 2021 Paul Hänsch
 #
 # This is a file format helper, part of CGIlite.
 # 
@@ -25,41 +25,40 @@ BR='
 '
 
 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"
@@ -67,11 +66,6 @@ RELEASE(){
   fi
 }
 
-# STRING='
-#   s;\\;\\\\;g; s;\t;\\t;g;
-#   s;\n;\\n;g;  s;\r;\\r;g;
-#   s;\+;\\+;g;  s; ;+;g;
-# '
 STRING(){
   local in out=''
   [ $# -gt 0 ] && in="$*" || in="$(cat)"
@@ -84,19 +78,9 @@ STRING(){
     " "*) out="${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(){
   local in out=''
   [ $# -gt 0 ] && in="$*" || in="$(cat)"
@@ -110,7 +94,7 @@ UNSTRING(){
     \\*) in="${in#\\}" ;;
     *) out="${out}${in%%[\\+]*}"; in="${in#"${in%%[\\+]*}"}" ;;
   esac; done
-  printf '%s' "$out"
+  printf '%s\n' "$out"
 }
 
 DBM() {