X-Git-Url: https://git.plutz.net/?p=cgilite;a=blobdiff_plain;f=storage.sh;h=22e6accbcba7cddd75bbaec0235a174b4aa53bd3;hp=0d09b262b4d700dac399dbc165ff5250570d16fa;hb=e02243e96d7cc400b63c3e856d0e80d4140c6805;hpb=ec06ef45d19a1a76462e5f871e0c40ce6c5b4f4e

diff --git a/storage.sh b/storage.sh
index 0d09b26..22e6acc 100755
--- a/storage.sh
+++ b/storage.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright 2018 Paul Hänsch
+# Copyright 2018, 2019, 2021 Paul Hänsch
 #
 # This is a file format helper, part of CGIlite.
 # 
@@ -20,74 +20,172 @@
 [ -n "$include_storage" ] && return 0
 include_storage="$0"
 
+CR="
"
+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
 }