jcha-capture

#!/bin/sh

# ---------------------------------------------------------------------------
# jcha - Java Class Histogram Analyser
#        Capture script
# ---------------------------------------------------------------------------

#######################################################################################
# Copyright 2014-present trivago GmbH
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#######################################################################################

if test $# = 0 -o  $# -gt 4; then
 echo "Usage: $0 [ [count] delaySeconds ] pid filnamePrefix"
 exit 1
fi

delaySecs=300
rounds=infinite

if test $# = 4; then
  rounds=$1
  shift
fi
if test $# = 3; then
  delaySecs=$1
  shift
fi
if test $# = 2; then
  thepid=$1
  shift
fi
if test $# = 1; then
  filePrefix=$1
  shift
fi

echo "Start capturing pid=${thepid} on ${filePrefix}.<datetime>.jch, delay=${delaySecs}s, count=${rounds}"
if test "x$count" = "xinfinite"; then
   echo "Running infinitely long. Press CTRL-c to stop"
fi

while test $rounds != 0; do
    dts=`date '+%Y%m%d-%H%M%S'`
    currentFileName=${filePrefix}-${dts}.jch
    echo $currentFileName
    jcmd ${thepid} GC.class_histogram > $currentFileName
    sleep $delaySecs
    if test "x$count" != "xinfinite"; then
        let rounds-=1
    fi
done