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edu.sdsc.grid.io
Class Host

java.lang.Object
  edu.sdsc.grid.io.Host

public final class Host
extends java.lang.Object
extends java.lang.Object

The Host class describes important attributes of the current host processor, compiler, and operating system. Attributes include:

Byte order
Data type storage sizes
Data type significant bits
Data type storage alignment (imposed by compiler)

All methods and fields of this class are static. Object instances of this class cannot be created.

Attributes

Byte order
For all data types requiring more than one byte (i.e., sizeof(type)>1), the processor stores the value as a sequence of bytes. That sequence may place the highest-order bytes first or last:

Big endian = Most-significant Byte First = MBF
Little endian = Least-significant Byte First = LBF

Intel processors are LBF, while most other processors are MBF. Java is always MBF, regardless of processor.
Data type storage sizes
Java defines fixed values, independent of processor, for the storage size of each primitive type.
Data type significant bits
The significant bits of a data type are the bits that may be set when using a value of that type. In Java this is the same number of bits as used to store that type.
Data type storage alignment
Storage alignment forces data types to start on half-word, word, or double-word address boundaries (depending on the type). This data cannot be determined, or used, in Java applications.

methods

Cast methods
Methods named "castToType" where "Type" is "Short," "Int", etc., provide a smart method of casting bytes from a raw byte array into a data type's value. For instance, if an array "bytes" contains a 4-byte float, then use:
float value = Host.castToFloat( bytes );

Copy methods
Methods named "copyType" where "Type" is "Short," "Int," etc., provide a smart method of copying a data typed value into a raw byte array. For instance, if a 4-byte float value needs to be copied into the next 4 bytes in a "bytes" array, then use:
Host.copyFloat( value, bytes );

Sub-classing: Final
Thread safe: Yes

Field Summary
`static int`	`CHAR` A language primitive signed or unsigned char.
`static int`	`DOUBLE` A language primitive double.
`static int`	`FLOAT` A language primitive float.
`static int`	`INT` A language primitive signed or unsigned integer.
`static int`	`LONG` A language primitive signed or unsigned long integer.
`static int`	`LONGDOUBLE` A language primitive long double.
`static int`	`LONGLONG` A language primitive signed or unsigned long long integer.
`static int`	`MAX_TYPE_SIZE` The guaranteed maximum number of bytes ever needed to hold the largest data type.
`static int`	`NUMBER_TYPES` The number of language primitive types.
`static int`	`SHORT` A language primitive signed or unsigned short integer.

Constructor Summary
`Host()`

Method Summary
`static short`	`castToByte(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static short`	`castToByte(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static double`	`castToDouble(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static double`	`castToDouble(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static float`	`castToFloat(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static float`	`castToFloat(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static int`	`castToInt(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static int`	`castToInt(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToLong(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToLong(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static double`	`castToLongDouble(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static double`	`castToLongDouble(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToLongLong(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToLongLong(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static short`	`castToShort(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static short`	`castToShort(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToUnsignedInt(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToUnsignedInt(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToUnsignedLong(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToUnsignedLong(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToUnsignedLongLong(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static long`	`castToUnsignedLongLong(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static int`	`castToUnsignedShort(byte[] bytes)` Casts bytes from the given byte array into a value of the type and returns it.
`static int`	`castToUnsignedShort(byte[] bytes, int offset)` Casts bytes from the given byte array into a value of the type and returns it.
`static void`	`copyDouble(double value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyDouble(double value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyFloat(double value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyFloat(double value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyFloat(float value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyFloat(float value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyInt(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLong(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLongDouble(double value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLongDouble(double value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyLongLong(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyShort(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedInt(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLong(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedLongLong(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(byte value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(byte value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(int value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(int value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(long value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(long value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(short value, byte[] bytes)` Copies the given value of the type into the given byte array.
`static void`	`copyUnsignedShort(short value, byte[] bytes, int offset)` Copies the given value of the type into the given byte array.
`static int`	`getCompilerAlignment(int type)` Gets the alignment boundary, in bytes, imposed by the compiler for the type.
`static java.lang.String`	`getName(int type)` Gets the name of the type.
`static int`	`getSignificantBits(int type)` Gets the number of significant bits of the type.
`static byte`	`getStorageSize(int type)` Gets the number of bytes occupied by the type.
`static boolean`	`isLBFByteOrder()` Returns true if the host's byte order is "little endian" or Least-significant-Byte-First (LBF); otherwise false.
`static boolean`	`isMBFByteOrder()` Returns true if the host's byte order is "big endian" or Most-significant-Byte-First (MBF); otherwise false.
`static void`	`print()` Prints to System.out the attributes of the current host.
`static void`	`swap(byte[] bytes, int nBytes)` Reverses the byte order of the first nBytes of the byte array.
`static void`	`swap(byte[] bytes, int offset, int nBytes)` Reverses the byte order of nBytes of the byte array, starting at the given offset.
`static void`	`swapMultiple(byte[] bytes, int nBytes, int nTimes)` Reverses the byte order of nBytes of the byte array, doing it nTimes in a row for consecutive runs of nBytes.
`static void`	`swapMultiple(byte[] bytes, int offset, int nBytes, int nTimes)` Reverses the byte order of nBytes of the byte array, starting at the given offset, and doing it nTimes in a row for consecutive runs of nBytes.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

CHAR

public static final int CHAR

A language primitive signed or unsigned char.

See Also:: Constant Field Values

SHORT

public static final int SHORT

A language primitive signed or unsigned short integer.

See Also:: Constant Field Values

INT

public static final int INT

A language primitive signed or unsigned integer.

See Also:: Constant Field Values

LONG

public static final int LONG

A language primitive signed or unsigned long integer.

See Also:: Constant Field Values

LONGLONG

public static final int LONGLONG

A language primitive signed or unsigned long long integer.

See Also:: Constant Field Values

FLOAT

public static final int FLOAT

A language primitive float.

See Also:: Constant Field Values

DOUBLE

public static final int DOUBLE

A language primitive double.

See Also:: Constant Field Values

LONGDOUBLE

public static final int LONGDOUBLE

A language primitive long double.

See Also:: Constant Field Values

NUMBER_TYPES

public static final int NUMBER_TYPES

The number of language primitive types.

See Also:: Constant Field Values

MAX_TYPE_SIZE

public static final int MAX_TYPE_SIZE

The guaranteed maximum number of bytes ever needed to hold the largest data type. This value may used to pre-allocate byte arrays used for read, writing, and byte-flipping values of any primitive data type.

The maximum value is intentionally set large in order to accomodate current and future architectures.

See Also:: Constant Field Values

Constructor Detail

Host

public Host()

Method Detail

isMBFByteOrder

public static final boolean isMBFByteOrder()

Returns true if the host's byte order is "big endian" or Most-significant-Byte-First (MBF); otherwise false.

Returns:: true if MBF; false if LBF

isLBFByteOrder

public static final boolean isLBFByteOrder()

Returns true if the host's byte order is "little endian" or Least-significant-Byte-First (LBF); otherwise false.

Returns:: true if LBF; false if MBF

getName

public static final java.lang.String getName(int type)

Gets the name of the type.

Parameters:: type - the type code for the data type
Returns:: the type name

getStorageSize

public static final byte getStorageSize(int type)

Gets the number of bytes occupied by the type.

Parameters:: type - the type code for the data type
Returns:: the number of bytes

getSignificantBits

public static final int getSignificantBits(int type)

Gets the number of significant bits of the type.

Parameters:: type - the type code for the data type
Returns:: the number of bytes

getCompilerAlignment

public static final int getCompilerAlignment(int type)

Gets the alignment boundary, in bytes, imposed by the compiler for the type.

Parameters:: type - the type code for the data type
Returns:: the alignment in bytes

swap

public static final void swap(byte[] bytes,
                              int nBytes)

Reverses the byte order of the first nBytes of the byte array. This method can be used to convert a byte array from Most- to Least-significant-Byte-First, or vice versa.

The swap is done in-place, reversing the order of bytes in the given array.

Parameters:: bytes - an array of bytes to swap the order of; nBytes - the number of bytes to swap

swap

public static final void swap(byte[] bytes,
                              int offset,
                              int nBytes)

Reverses the byte order of nBytes of the byte array, starting at the given offset. This method can be used to convert a byte array from Most- to Least-significant-Byte-First, or vice versa.

The swap is done in-place, reversing the order of bytes in the given array.

Parameters:: bytes - an array of bytes to swap the order of; offset - the starting point in the bytes array; nBytes - the number of bytes to swap

swapMultiple

public static final void swapMultiple(byte[] bytes,
                                      int nBytes,
                                      int nTimes)

Reverses the byte order of nBytes of the byte array, doing it nTimes in a row for consecutive runs of nBytes. This method can be used to convert a byte array containing multiple values, swaping each one from Most- to Least-significant-Byte-First, or vice versa.

The swap is done in-place, reversing the order of bytes in the given array.

Parameters:: bytes - an array of bytes to swap the order of; nBytes - the number of bytes to swap; nTimes - the number of times to do consecutive swaps

swapMultiple

public static final void swapMultiple(byte[] bytes,
                                      int offset,
                                      int nBytes,
                                      int nTimes)

Reverses the byte order of nBytes of the byte array, starting at the given offset, and doing it nTimes in a row for consecutive runs of nBytes. This method can be used to convert a byte array containing multiple values, swaping each one from Most- to Least-significant-Byte-First, or vice versa.

The swap is done in-place, reversing the order of bytes in the given array.

Parameters:: bytes - an array of bytes to swap the order of; offset - starting point in the array; nBytes - the number of bytes to swap; nTimes - the number of times to do consecutive swaps

castToByte

public static final short castToByte(byte[] bytes)

Casts bytes from the given byte array into a value of the type and returns it. The bytes in the array need not be aligned appropriately for the type. The array is assumed to contain a legal value for the type with sizeof(type) bytes in the Java byte order.

Because Java doesn't support unsigned primitive types, this method returns the value in the next larger data type, with the high bits set to zeroes.

Parameters:: bytes - byte array
Returns:: the unsigned byte value (as an short)

castToShort

public static final short castToShort(byte[] bytes)

Parameters:: bytes - byte array
Returns:: the short value

castToUnsignedShort

public static final int castToUnsignedShort(byte[] bytes)

Because Java doesn't support unsigned primitive types, this method returns the value in the next larger data type, with the high bits set to zeroes.

Parameters:: bytes - byte array
Returns:: the unsigned short value (as an int)

castToInt

public static final int castToInt(byte[] bytes)

Parameters:: bytes - byte array
Returns:: the int value

castToUnsignedInt

public static final long castToUnsignedInt(byte[] bytes)

Because Java doesn't support unsigned primitive types, this method returns the value in the next larger data type, with the high bits set to zeroes.

Parameters:: bytes - byte array
Returns:: the unsigned int value (as a long)

castToLong

public static final long castToLong(byte[] bytes)

Parameters:: bytes - byte array
Returns:: the long value

castToUnsignedLong

public static final long castToUnsignedLong(byte[] bytes)

Parameters:: bytes - byte array
Returns:: the unsigned long value

castToLongLong

public static final long castToLongLong(byte[] bytes)

Note: Since Java does not support long long types, this method is identical to the long version.

Parameters:: bytes - byte array
Returns:: the long long value

castToUnsignedLongLong

public static final long castToUnsignedLongLong(byte[] bytes)

Note: Since Java does not support long long types, this method is identical to the long version.

Parameters:: bytes - byte array
Returns:: the unsigned long long value

castToFloat

public static final float castToFloat(byte[] bytes)

Parameters:: bytes - byte array
Returns:: the float value

castToDouble

public static final double castToDouble(byte[] bytes)

Parameters:: bytes - byte array
Returns:: the double value

castToLongDouble

public static final double castToLongDouble(byte[] bytes)

Note: Since Java does not support long double types, this method is identical to the double version.

Parameters:: bytes - byte array
Returns:: the long double value

castToByte

public static final short castToByte(byte[] bytes,
                                     int offset)

Because Java doesn't support unsigned primitive types, this method returns the value in the next larger data type, with the high bits set to zeroes.

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the unsigned byte value (as a short)

castToShort

public static final short castToShort(byte[] bytes,
                                      int offset)

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the short value

castToUnsignedShort

public static final int castToUnsignedShort(byte[] bytes,
                                            int offset)

Because Java doesn't support unsigned primitive types, this method returns the value in the next larger data type, with the high bits set to zeroes.

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the unsigned short value (as an int)

castToInt

public static final int castToInt(byte[] bytes,
                                  int offset)

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the int value

castToUnsignedInt

public static final long castToUnsignedInt(byte[] bytes,
                                           int offset)

Because Java doesn't support unsigned primitive types, this method returns the value in the next larger data type, with the high bits set to zeroes.

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the unsigned int value (as a long)

castToLong

public static final long castToLong(byte[] bytes,
                                    int offset)

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the long value

castToUnsignedLong

public static final long castToUnsignedLong(byte[] bytes,
                                            int offset)

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the unsigned long value

castToLongLong

public static final long castToLongLong(byte[] bytes,
                                        int offset)

Note: Since Java does not support long long types, this method is identical to the long version.

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the long long value

castToUnsignedLongLong

public static final long castToUnsignedLongLong(byte[] bytes,
                                                int offset)

Note: Since Java does not support long long types, this method is identical to the long version.

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the unsigned long long value

castToFloat

public static final float castToFloat(byte[] bytes,
                                      int offset)

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the float value

castToDouble

public static final double castToDouble(byte[] bytes,
                                        int offset)

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the double value

castToLongDouble

public static final double castToLongDouble(byte[] bytes,
                                            int offset)

Note: Since Java does not support long double types, this method is identical to the double version.

Parameters:: bytes - byte array; offset - starting point in byte array
Returns:: the long double value