#!/bin/sh
#
# This is unsupport sample deleting cache files script.
# So s3fs's local cache files(stats and objects) grow up,
# you need to delete these.
# This script deletes these files with total size limit
# by sorted atime of files.
# You can modify this script for your system.
#
# [Usage] script <bucket name> <cache path> <limit size> [-silent]
#

func_usage()
{
  echo ""
  echo "Usage:  $1 <bucket name> <cache path> <limit size> [-silent]"
  echo "        $1 -h"
  echo "Sample: $1 mybucket /tmp/s3fs/cache 1073741824"
  echo ""
  echo "  bucket name = bucket name which specified s3fs option"
  echo "  cache path  = cache directory path which specified by"
  echo "                use_cache s3fs option."
  echo "  limit size  = limit for total cache files size."
  echo "                specify by BYTE"
  echo "  -silent     = silent mode"
  echo ""
}

PRGNAME=`basename $0`

if [ "X$1" = "X-h" -o "X$1" = "X-H" ]; then
  func_usage $PRGNAME
  exit 0
fi
if [ "X$1" = "X" -o "X$2" = "X" -o "X$3" = "X" ]; then
  func_usage $PRGNAME
  exit 1
fi

BUCKET=$1
CDIR="$2"
LIMIT=$3
SILENT=0
if [ "X$4" = "X-silent" ]; then
  SILENT=1
fi
FILES_CDIR="${CDIR}/${BUCKET}"
STATS_CDIR="${CDIR}/.${BUCKET}.stat"
CURRENT_CACHE_SIZE=`du -sb "$FILES_CDIR" | awk '{print $1}'`
#
# Check total size
#
if [ $LIMIT -ge $CURRENT_CACHE_SIZE ]; then
  if [ $SILENT -ne 1 ]; then
    echo "$FILES_CDIR ($CURRENT_CACHE_SIZE) is below allowed $LIMIT"
  fi
  exit 0
fi

#
# Remove loop
#
TMP_ATIME=0
TMP_STATS=""
TMP_CFILE=""
#
# Make file list by sorted access time
#
find "$STATS_CDIR" -type f -exec stat -c "%X:%n" "{}" \; | sort | while read part
do
  echo Looking at $part
  TMP_ATIME=`echo "$part" | cut -d: -f1`
  TMP_STATS="`echo "$part" | cut -d: -f2`"
  TMP_CFILE=`echo "$TMP_STATS" | sed s/\.$BUCKET\.stat/$BUCKET/`
  
  if [ `stat -c %X "$TMP_STATS"` -eq $TMP_ATIME ]; then
    rm -f "$TMP_STATS" "$TMP_CFILE" > /dev/null 2>&1
    if [ $? -ne 0 ]; then
      if [ $SILENT -ne 1 ]; then
        echo "ERROR: Could not remove files($TMP_STATS,$TMP_CFILE)"
      fi
      exit 1
    else
      if [ $SILENT -ne 1 ]; then
        echo "remove file: $TMP_CFILE	$TMP_STATS"
      fi
    fi
  fi
  if [ $LIMIT -ge `du -sb "$FILES_CDIR" | awk '{print $1}'` ]; then
    if [ $SILENT -ne 1 ]; then
      echo "finish removing files"
    fi
    break
  fi
done

if [ $SILENT -ne 1 ]; then
  TOTAL_SIZE=`du -sb "$FILES_CDIR" | awk '{print $1}'`
  echo "Finish: $FILES_CDIR total size is $TOTAL_SIZE"
fi

exit 0

#
# End
#
