Class Constants

java.lang.Object
org.apache.lucene.util.Constants

public final class Constants extends Object
Some useful constants.
  • Field Details

    • UNKNOWN

      private static final String UNKNOWN
      See Also:
    • JVM_VENDOR

      public static final String JVM_VENDOR
      JVM vendor info.
    • JVM_NAME

      public static final String JVM_NAME
      JVM vendor name.
    • OS_NAME

      public static final String OS_NAME
      The value of System.getProperty("os.name"). *
    • LINUX

      public static final boolean LINUX
      True iff running on Linux.
    • WINDOWS

      public static final boolean WINDOWS
      True iff running on Windows.
    • SUN_OS

      public static final boolean SUN_OS
      True iff running on SunOS.
    • MAC_OS_X

      public static final boolean MAC_OS_X
      True iff running on Mac OS X
    • FREE_BSD

      public static final boolean FREE_BSD
      True iff running on FreeBSD
    • OS_ARCH

      public static final String OS_ARCH
      The value of System.getProperty("os.arch").
    • OS_VERSION

      public static final String OS_VERSION
      The value of System.getProperty("os.version").
    • JAVA_VENDOR

      public static final String JAVA_VENDOR
      The value of System.getProperty("java.vendor").
    • IS_CLIENT_VM

      public static final boolean IS_CLIENT_VM
      True iff the Java runtime is a client runtime and C2 compiler is not enabled.
    • IS_HOTSPOT_VM

      public static final boolean IS_HOTSPOT_VM
      True iff the Java VM is based on Hotspot and has the Hotspot MX bean readable by Lucene.
    • IS_JVMCI_VM

      public static final boolean IS_JVMCI_VM
      True if jvmci is enabled (e.g. graalvm)
    • JRE_IS_64BIT

      public static final boolean JRE_IS_64BIT
      True iff running on a 64bit JVM
    • HAS_FMA

      private static final boolean HAS_FMA
      true if FMA likely means a cpu instruction and not BigDecimal logic.
    • MAX_VECTOR_SIZE

      private static final int MAX_VECTOR_SIZE
      maximum supported vectorsize.
    • HAS_SSE4A

      private static final boolean HAS_SSE4A
      true for an AMD cpu with SSE4a instructions.
    • HAS_FAST_VECTOR_FMA

      public static final boolean HAS_FAST_VECTOR_FMA
      true iff we know VFMA has faster throughput than separate vmul/vadd.
    • HAS_FAST_SCALAR_FMA

      public static final boolean HAS_FAST_SCALAR_FMA
      true iff we know FMA has faster throughput than separate mul/add.
    • DEFAULT_READADVICE

      public static final ReadAdvice DEFAULT_READADVICE
      The default ReadAdvice used for opening index files. It will be ReadAdvice.RANDOM by default, unless set by system property org.apache.lucene.store.defaultReadAdvice.
  • Constructor Details

    • Constants

      private Constants()
  • Method Details

    • is64Bit

      private static boolean is64Bit()
    • hasFastVectorFMA

      private static boolean hasFastVectorFMA()
    • hasFastScalarFMA

      private static boolean hasFastScalarFMA()
    • getSysProp

      private static String getSysProp(String property)
    • getSysProp

      private static String getSysProp(String property, String def)
    • logSecurityWarning

      private static void logSecurityWarning(String property)
    • doPrivileged

      private static <T> T doPrivileged(PrivilegedAction<T> action)