X-Git-Url: https://git.plutz.net/?p=cgilite;a=blobdiff_plain;f=storage.sh;h=22e6accbcba7cddd75bbaec0235a174b4aa53bd3;hp=bf8b7b9f44343d3c210c57800b5e606208f6e6b2;hb=e02243e96d7cc400b63c3e856d0e80d4140c6805;hpb=438b528a68c8638b7681e7dca95ee225d07df48d

diff --git a/storage.sh b/storage.sh
index bf8b7b9..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.
 # 
@@ -17,57 +17,175 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with CGIlite.  If not, see <http://www.gnu.org/licenses/>. 
 
-# ksh and zsh workaround
-case "${0##*/}" in
-  zsh) setopt -o OCTAL_ZEROES 2>&- ;; # zsh, mostly ignored by other shells
-  ksh) set -o posix ;;                # ksh, will crash most other shells
-esac
+[ -n "$include_storage" ] && return 0
+include_storage="$0"
 
-STORE(){
-  # Store fields from a HTTP GET or POST string in a file
-  # usage: STORE "${QUERY_STRING}"
-  #    or: STORE "$(head -n $HTTP_CONTENT_LENGTH)"
-  # backslashes and newline characters will be escaped in field values,
-  # the escape symbol is a backslash
-  # hexadecimal character descriptions (%00 - %FF) will be expanded
-  # the + character will be converted to [space]
-  # one line in the output corresponds to exactly one field, so you can
-  # use grep to filter which fields of a query should be stored
-  printf "$(
-  printf '%s' "$@" \
-  | sed -r ':X; $bY; N; bX; :Y;
-            s;\+; ;g; s;(\\|5[Cc]);\\\\\\\\;g; s;(\n|%0[Aa]);\\\\n;g; s;(^|&)([^=]+)=;\1\2:;g; s;&;\n;g;
-            s;^\n+;;; s;$;\\n;; s;\n+;\n;g;
-            # Hexadecimal { %00 - %FF } will be transformed to octal { \000 - \377 } for posix printf
-            s;%[0123].;&\\0;g; s;%[4567].;&\\1;g; s;%[89AB].;&\\2;g; s;%[CDEF].;&\\3;g;
-            s;%[048C][0-7]\\.;&0;g; s;%[048C][89A-F]\\.;&1;g; s;%[159D][0-7]\\.;&2;g; s;%[159D][89A-F]\\.;&3;g;
-            s;%[26AE][0-7]\\.;&4;g; s;%[26AE][89A-F]\\.;&5;g; s;%[37BF][0-7]\\.;&6;g; s;%[37BF][89A-F]\\.;&7;g;
-            s;%.[08](\\..);\10;g; s;%.[19](\\..);\11;g; s;%.[2A](\\..);\12;g; s;%.[3B](\\..);\13;g;
-            s;%.[4C](\\..);\14;g; s;%.[5D](\\..);\15;g; s;%.[6E](\\..);\16;g; s;%.[7F](\\..);\17;g;
-           ' 
-  )"
+CR="
"
+BR='
+'
+
+LOCK(){
+  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 [ $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
+  done
+
+  debug "Timeout while trying to get lock: $lock"
+  return 1
+}
+
+RELEASE(){
+  local lock="${1}.lock" block
+
+  read block <"$lock"
+  if [ "$block" = $$ ]; then
+    rm -- "$lock"
+    return 0
+  else
+    debug "Refusing to release foreign lock: $lock"
+    return 1
+  fi
+}
+
+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(){
+  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"
 }
 
-LOAD(){
-  # read a file written by STORE and assign all fields to variables
-  # usage: eval "$(LOAD <file)"
-  #
-  # fields will be assigned to shell variables of the same name, but with the following constraints:
-  # * small letters will be converted to capitals
-  # * all non-alphanumeric characters will be converted to underscore (_)
-  # * an underscore will be prepended
-  # as a consequence variable names are guaranteed to match the regex /_[A-Z0-9_]+/
-  #
-  # field values may contain any character, proper escaping for safe use in eval is taken care of
-  # Your shell may or may not purge certain binary characters from variable values during processing
+DBM() {
+  local file="$1" cmd="$2"
+  local k v key value
+  shift 2;
 
-  sed -r 'h; s;^[^:]+:;;
-          s;'\'';'\''\\'\'\'';g;
-          s;^.*$;'\''&'\'';;
-          s;\\n;\n;g;
-          x; s;^([^:]+):.*$;\1;
-          y;abcdefghijklmnopqrstuvwxyz;ABCDEFGHIJKLMNOPQRSTUVWXYZ;
-          s;[^A-Z0-9_];_;g; s;^.*$;_&=;;
-          G; s;^([A-Z0-9_]+=)\n;\1;;
-         '
+  case "$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
 }