#!/bin/bash
TIMEOUT=2
SERVERS=("127.0.0.1:11211")
DEFAULTPORT=11211
KEYLIMIT=100


function usage {
    echo ""
    echo "$0 [regex]"
    echo "Used to invalidate keys on memcached servers"
    echo ""
}

function memcache_netcat {
    netcat -q $TIMEOUT $SERVER $PORT
}

function memcache_delete {
    echo "DELETING: $1"
    RESULT=$(echo "delete $1" | memcache_netcat)
}

# Parameter is required
if [ -z $1 ]; then
    usage
    exit 1
fi




# For each server... (in SERVER:PORT format)
for definition in "${SERVERS[@]}"
do
    IFS=':'
    read -ra server <<< "$definition"
    SERVER=${server[0]}
    PORT=${server[1]-$DEFAULTPORT}
    LOOPS=0

    echo ""
    echo "Invalidating keys on: $SERVER:$PORT"
    echo "Searching for       : $1"
    echo ""
    echo "stats items" | memcache_netcat | while read line;
    do
        LOOPS=$[$LOOPS+1]
        let "ITERS=$LOOPS % 10"

        # Each STATS ITEM row brings back 10 statistics. Skip all but first row.
        if [ $ITERS -eq 1 ]; then
            read -ra chunks <<< "$line"

            # If this not a STATS ITEMS row, skip it
            if [ ${#chunks[@]} -lt 3 ]; then
                continue
            fi

            SLAB=${chunks[1]}
            XIFS=$IFS
            IFS=" "

            # Search this slab for the keys it contains
            echo "stats cachedump $SLAB $KEYLIMIT" | memcache_netcat | while read row;
            do
                # If the key matches the search, delete
                KEY=`echo "$row" | tr -d '\b\r' | sed 's/^.\{4\} \([^ ]*\).*$/\1/'`
                if [[ $KEY = "END" ]]; then
                    continue
                fi

                if [[ $KEY =~ $1 ]]; then
                    read -ra parts <<< "$row"
                    memcache_delete $KEY
                fi

            done

            IFS=$XIFS
        fi
    done

done

echo "DONE."
echo ""