emc

README

Enhanced JVM Meomry Calculator

emc is enhanced cloudfoundry/java-buildpack-memory-calculator and inspired by making/memory-calculator-cnb. emc counts classes in directory and classes in jar, and show memory options.

# emc counts class in directory recursively. also supports jar in directory.
$ emc --total-memory 1G <path/to/directory>
-XX:MaxDirectMemorySize=10M -XX:MaxMetaspaceSize=14447K -XX:ReservedCodeCacheSize=240M -Xmx266128K

# emc counts class in jar recursively. also supports UberJar.
$ emc --total-memory 1G <path/to/your.jar>
-XX:MaxDirectMemorySize=10M -XX:MaxMetaspaceSize=14447K -XX:ReservedCodeCacheSize=240M -Xmx266128K

Install

# emc is not released yet. you can try with go get.
go get github.com/wreulicke/emc/cmd/emc

Usage

$ go run ./cmd/emc/ --help
usage: emc [<flags>] [<jarOrDirectory>]

Enhanced java memory calculator

Flags:
      --help              Show context-sensitive help (also try --help-long and --help-man).
  -v, --verbose           Verbose
      --total-memory=TOTAL-MEMORY  
                          Total memory. Required if is not limited by cgroup
      --loaded-class-count=LOADED-CLASS-COUNT  
                          Loaded class count
      --thread-count=250  thread count
      --java-options=""   JVM Options
      --head-room=0       Percentage of total memory available which will be left unallocated to cover JVM overhead
      --java-version=11    Java version

Args:
  [<jarOrDirectory>]  jar or directory

LICENSE

MIT LICENSE

Documentation

Index

• func Calculate(totalMemory int64, loadedClassCount int64, threadCount int64, ...) ([]string, error)
• func CountClassFile(file *os.File, fi os.FileInfo) (int64, error)
• func CountClassFileInDir(dir *os.File) (int64, error)
• func CountClassFileInJar(z *zip.Reader, pathPrefix string) (int64, error)
• func CountClassInStandardLibrary(version int) int64

Functions

func Calculate

func Calculate(totalMemory int64, loadedClassCount int64, threadCount int64, javaOptons string, headRoom int) ([]string, error)

func CountClassFile

func CountClassFile(file *os.File, fi os.FileInfo) (int64, error)

func CountClassFileInDir

func CountClassFileInDir(dir *os.File) (int64, error)

func CountClassFileInJar

func CountClassFileInJar(z *zip.Reader, pathPrefix string) (int64, error)

func CountClassInStandardLibrary

func CountClassInStandardLibrary(version int) int64