javacardx.framework.util
Class ArrayLogic

java.lang.Object
  javacardx.framework.util.ArrayLogic

public final class ArrayLogic
extends Object

The ArrayLogic class contains common utility functions for manipulating arrays of primitive components - byte, short or int. Some of the methods may be implemented as native functions for performance reasons. All the methods in ArrayLogic class are static methods.

Some methods of ArrayLogic, namely arrayCopyRepack(), arrayCopyRepackNonAtomic() and arrayFillGenericNonAtomic(), refer to the persistence of array objects. The term persistent means that arrays and their values persist from one CAD session to the next, indefinitely. The JCSystem class is used to control the persistence and transience of objects.

Since:

2.2.2

See Also:

javacard.framework.JCSystem

Method Summary

static byte	arrayCompareGeneric(Object src, short srcOff, Object dest, short destOff, short length) Compares an array from the specified source array, beginning at the specified position, with the specified position of the destination array from left to right.
static short	arrayCopyRepack(Object src, short srcOff, short srcLen, Object dest, short destOff) Copies data from the specified source array, beginning at the specified position, to the specified position of the destination array.
static short	arrayCopyRepackNonAtomic(Object src, short srcOff, short srcLen, Object dest, short destOff) Non-atomically copies data from the specified source array, beginning at the specified position, to the specified position of the destination array.
static short	arrayFillGenericNonAtomic(Object theArray, short off, short len, Object valArray, short valOff) Fills the array of primitive components(non-atomically) beginning at the specified position, for the specified length with the specified value.
static short	arrayFindGeneric(Object theArray, short off, byte[] valArray, short valOff) Finds the first occurrence of the specified value within the specified array.

Methods inherited from class java.lang.Object

equals

Method Detail

arrayCopyRepack

public static final short arrayCopyRepack(Object src,
                                          short srcOff,
                                          short srcLen,
                                          Object dest,
                                          short destOff)
                                   throws ArrayIndexOutOfBoundsException,
                                          NullPointerException,
                                          TransactionException,
                                          UtilException

Copies data from the specified source array, beginning at the specified position, to the specified position of the destination array. Note that this method may be used to copy from an array of any primitive component - byte, short or int to another (or same) array of any primitive component - byte, short or int. If the source array primitive component size is smaller than that of the destination array, a packing conversion is performed; if the source array primitive component size is larger than that of the destination array, an unpacking operation is performed; if the source and destination arrays are of the same component type, simple copy without any repacking is performed.

Note:

• If the source array is a byte array and the destination is a short array, then pairs of source array bytes are concatenated (high order byte component first) to form short components before being written to the destination short array. If the srcLen parameter is not a multiple of 2, an UtilException exception is thrown.
• If the source array is a byte array and the destination is an int array, 4 bytes of the source array are concatenated at a time (high order byte component first) to form int components before being written to the destination int array. If the srcLen parameter is not a multiple of 4, an UtilException exception is thrown.
• If the source array is a short array and the destination is an int array, then pairs of source array bytes are concatenated (high order short component first) to form int components before being written to the destination int array. If the srcLen parameter is not a multiple of 2, an UtilException exception is thrown.
• If the source array is a short array and the destination is a byte array, then each short component is split into 2 bytes (high order byte component first) before being written sequentially to the destination byte array.
• If the source array is a int array and the destination is a short array, then each int component is split into 2 shorts (high order short component first) before being written sequentially to the destination short array.
• If the source array is a int array and the destination is a byte array, then each int component is split into 4 bytes (high order byte component first) before being written sequentially to the destination byte array.
• If srcOff or destOff or srcLen parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
• If srcOff+srcLen is greater than src.length, the length of the src array a ArrayIndexOutOfBoundsException exception is thrown and no copy is performed.
• If offset into the dest array would become greater than dest.length, the length of the dest array during the copy operation ArrayIndexOutOfBoundsException exception is thrown and no copy is performed.
• If src or dest parameter is null
a NullPointerException exception is thrown.
• If the src and dest arguments refer to the same array object, then the copying is performed as if the components at positions srcOff through srcOff+srcLen-1 were first copied to a temporary array with srcLen components and then the contents of the temporary array were copied into positions destOff through destOff+srcLen-1 of the destination array.
• If the destination array is persistent, the entire copy is performed atomically.
• The copy operation is subject to atomic commit capacity limitations. If the commit capacity is exceeded, no copy is performed and a TransactionException exception is thrown.

Parameters:

src - source array object

srcOff - offset within source array to start copy from

srcLen - number of source component values to be copied from the source array

dest - destination array object

destOff - offset within destination array to start copy into

Returns:

a value of one more than the offset within the dest array where the last copy was performed

Throws:

ArrayIndexOutOfBoundsException - if copying would cause access of data outside array bounds

NullPointerException - if either src or dest is null

TransactionException - if copying would cause the commit capacity to be exceeded

UtilException - with the following reason codes:

• UtilException.ILLEGAL_VALUE if src or dest is not an array of primitive components, or if the srcLen parameter is incorrect

See Also:

javacard.framework.JCSystem.getUnusedCommitCapacity()

arrayCopyRepackNonAtomic

public static final short arrayCopyRepackNonAtomic(Object src,
                                                   short srcOff,
                                                   short srcLen,
                                                   Object dest,
                                                   short destOff)
                                            throws ArrayIndexOutOfBoundsException,
                                                   NullPointerException,
                                                   UtilException

Non-atomically copies data from the specified source array, beginning at the specified position, to the specified position of the destination array. Note that this method may be used to copy from an array of any primitive component - byte, short or int to another (or same) array of any primitive component - byte, short or int. If the source array primitive component size is smaller than that of the destination array, a packing conversion is performed; if the source array primitive component size is larger than that of the destination array, an unpacking operation is performed; if the source and destination arrays are of the same component type, simple copy without any repacking is performed.

This method does not use the transaction facility during the copy operation even if a transaction is in progress. Thus, this method is suitable for use only when the contents of the destination array can be left in a partially modified state in the event of a power loss in the middle of the copy operation.

Note:

• If the source array is a byte array and the destination is a short array, then pairs of source array bytes are concatenated (high order byte component first) to form short components before being written to the destination short array. If the srcLen parameter is not a multiple of 2, an UtilException exception is thrown.
• If the source array is a byte array and the destination is an int array, 4 bytes of the source array are concatenated at a time (high order byte component first) to form int components before being written to the destination int array. If the srcLen parameter is not a multiple of 4, an UtilException exception is thrown.
• If the source array is a short array and the destination is an int array, then pairs of source array bytes are concatenated (high order short component first) to form int components before being written to the destination int array. If the srcLen parameter is not a multiple of 2, an UtilException exception is thrown.
• If the source array is a short array and the destination is a byte array, then each short component is split into 2 bytes (high order byte component first) before being written sequentially to the destination byte array.
• If the source array is a int array and the destination is a short array, then each int component is split into 2 shorts (high order short component first) before being written sequentially to the destination short array.
• If the source array is a int array and the destination is a byte array, then each int component is split into 4 bytes (high order byte component first) before being written sequentially to the destination byte array.
• If srcOff or destOff or srcLen parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
• If srcOff+srcLen is greater than src.length, the length of the src array a ArrayIndexOutOfBoundsException exception is thrown and no copy is performed.
• If offset into the dest array would become greater than dest.length, the length of the dest array during the copy operation ArrayIndexOutOfBoundsException exception is thrown and no copy is performed.
• If src or dest parameter is null
a NullPointerException exception is thrown.
• If the src and dest arguments refer to the same array object, then the copying is performed as if the components at positions srcOff through srcOff+srcLen-1 were first copied to a temporary array with srcLen components and then the contents of the temporary array were copied into positions destOff through destOff+srcLen-1 of the destination array.

Parameters:

src - source array object

srcOff - offset within source array to start copy from

srcLen - number of source component values to be copied from the source array

dest - destination array object

destOff - offset within destination array to start copy into

Returns:

a value of one more than the offset within the dest array where the last copy was performed

Throws:

ArrayIndexOutOfBoundsException - if copying would cause access of data outside array bounds

NullPointerException - if either src or dest is null

UtilException - with the following reason codes:

• UtilException.ILLEGAL_VALUE if src or dest is not an array of primitive components, or if the srcLen parameter is incorrect

arrayFillGenericNonAtomic

public static final short arrayFillGenericNonAtomic(Object theArray,
                                                    short off,
                                                    short len,
                                                    Object valArray,
                                                    short valOff)
                                             throws ArrayIndexOutOfBoundsException,
                                                    NullPointerException,
                                                    UtilException

Fills the array of primitive components(non-atomically) beginning at the specified position, for the specified length with the specified value. Note that this method may be used to fill an array of any primitive component type - byte, short or int. The value used for the fill operation is itself specified using an array (valArray) of the same primitive component type at offset valOff.

This method does not use the transaction facility during the fill operation even if a transaction is in progress. Thus, this method is suitable for use only when the contents of the array can be left in a partially filled state in the event of a power loss in the middle of the fill operation.

The following code snippet shows how this method is typically used:

   public short[] myArray = new short[10];
  ..
  // Fill the entire array myArray of 10 short components with the value 0x1234
  myArray[0] = (short)0x1234;
  ArrayLogic.arrayFillGenericNonAtomic(myArray, (short)0, (short)10, myArray, (short)0);
  ..
 

Note:

• If off or len or valOff parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
• If off+len is greater than theArray.length, the length of the theArray array an ArrayIndexOutOfBoundsException exception is thrown.
• If valOff is equal to or greater than valArray.length, the length of the valArray array an ArrayIndexOutOfBoundsException exception is thrown.
• If theArray or valArray parameter is null a NullPointerException exception is thrown.
• If power is lost during the copy operation and the array is persistent, a partially changed array could result.
• The len parameter is not constrained by the atomic commit capacity limitations.

Parameters:

theArray - the array object

off - offset within array to start filling the specified value

len - the number of component values to be filled

valArray - the array object containing the fill value

valOff - the offset within the valArray array containing the fill value

Returns:

off+len

Throws:

ArrayIndexOutOfBoundsException - if the fill operation would cause access of data outside array bounds

NullPointerException - if theArray or valArray is null

UtilException - with the following reason codes:

• UtilException.ILLEGAL_VALUE if theArray or valArray is not an array of primitive components
• UtilException.TYPE_MISMATCHED if the valArray parameter is not an array of the same primitive component type as the theArray.

arrayCompareGeneric

public static final byte arrayCompareGeneric(Object src,
                                             short srcOff,
                                             Object dest,
                                             short destOff,
                                             short length)
                                      throws ArrayIndexOutOfBoundsException,
                                             NullPointerException,
                                             UtilException

Compares an array from the specified source array, beginning at the specified position, with the specified position of the destination array from left to right. Note that this method may be used to compare any two arrays of the same primitive component type - byte, short or int. Returns the ternary result of the comparison : less than(-1), equal(0) or greater than(1).

Note:

• If srcOff or destOff or length parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
• If srcOff+length is greater than src.length, the length of the src array a ArrayIndexOutOfBoundsException exception is thrown.
• If destOff+length is greater than dest.length, the length of the dest array an ArrayIndexOutOfBoundsException exception is thrown.
• If src or dest parameter is null a NullPointerException exception is thrown.

Parameters:

src - source array object

srcOff - offset within source array to start compare

dest - destination array object

destOff - offset within destination array to start compare

length - length to be compared

Returns:

the result of the comparison as follows:

• 0 if identical
• -1 if the first miscomparing primitive component in source array is less than that in destination array
• 1 if the first miscomparing primitive component in source array is greater than that in destination array

Throws:

ArrayIndexOutOfBoundsException - if comparing all the components would cause access of data outside array bounds

NullPointerException - if either src or dest is null

UtilException - with the following reason codes:

• UtilException.ILLEGAL_VALUE if src or dest is not an array of primitive components, or if the length parameter is incorrect
• UtilException.TYPE_MISMATCHED if the dest parameter is not an array of the same primitive component type.

arrayFindGeneric

public static final short arrayFindGeneric(Object theArray,
                                           short off,
                                           byte[] valArray,
                                           short valOff)
                                    throws ArrayIndexOutOfBoundsException,
                                           NullPointerException,
                                           UtilException

Finds the first occurrence of the specified value within the specified array. The search begins at the specified position and proceeds until the end of the array. Note that this method may be used to search an array of any primitive component type - byte, short or int. The value used in the search operation is itself specified by the appropriate number of consecutive bytes at offset valOff in the byte array parameter valArray.

Note:

• If off or valOff parameter is negative an ArrayIndexOutOfBoundsException exception is thrown.
• If off is greater than theArray.length, the length of the theArray array an ArrayIndexOutOfBoundsException exception is thrown.
• If theArray or valArray parameter is null a NullPointerException exception is thrown.
• If the specified array is an array of byte components, then the byte at valOff in the valArray is used as the search value. If valOff+1 is greater than valArray.length, the length of the valArray array an ArrayIndexOutOfBoundsException exception is thrown.
• If the specified array is an array of short components, then 2 consecutive bytes beginning at valOff in the valArray are concatenated (high order byte component first) to form the search value. If valOff+2 is greater than valArray.length, the length of the valArray array an ArrayIndexOutOfBoundsException exception is thrown.
• If the specified array is an array of int components, then 4 consecutive bytes beginning at valOff in the valArray are concatenated (high order byte component first) to form the search value. If valOff+4 is greater than valArray.length, the length of the valArray array an ArrayIndexOutOfBoundsException exception is thrown.

Parameters:

theArray - the array object to search

off - offset within the array to start serching for the specified value

valArray - the array object containing the search value

valOff - the offset within the valArray array containing the search value

Returns:

the offset into the specified array where the first occurrence of specified value was found or -1 if the specified value does not occur in the specified portion of the array

Throws:

ArrayIndexOutOfBoundsException - if the search operation would cause access of data outside array bounds

NullPointerException - if theArray is null

UtilException - with the following reason code:

• UtilException.ILLEGAL_VALUE if theArray is not an array of primitive components.