Geometric array data structure
View Patent ↗A method for implementing a geometric array in a computing environment is disclosed. In one embodiment, such a method includes providing an array of slots, where each slot is configured to store a pointer. Each pointer in the array points to a block of elements. Each pointer with the exception of the first pointer in the array points to a block of elements that is twice as large as the block of elements associated with the preceding pointer. Such a structure allows the geometric array to grow by simply adding a pointer to the array that points to a new block of elements that is twice as large as the block of elements associated with the preceding pointer in the array. A corresponding computer program product, as well as a method for accessing data in the geometric array, are also disclosed.
1. A computer program product to implement a geometric array in a computing environment, the computer program product comprising a non-transitory computer-usable storage medium having computer-usable program code embodied therein, the computer-usable program code comprising:
computer-usable program code to generate an array of slots, each slot configured to store a pointer, wherein each pointer in the array points to a block of elements, and each pointer with the exception of the first pointer in the array points to a block of elements that is twice as large as the block of elements associated with the preceding pointer.
2. The computer program product of claim 1 , wherein the elements within each block of elements are contiguous in memory.
3. The computer program product of claim 1 , further comprising computer-usable program code to expand the geometric array by allocating a new block of elements that is twice as large as the block of elements associated with the preceding pointer.
4. The computer program product of claim 3 , further comprising computer-usable program code to add a pointer pointing to the new block of elements to a next empty slot in the array of slots.
5. The computer program product of claim 1 , wherein the number of slots in the array is equal to N, where N is the number of bits in an address space of the computing environment.
6. The computer program product of claim 1 , wherein the number of slots in the array is less than N, where N is the number of bits in an address space of the computing environment.
7. The computer program product of claim 1 , further comprising computer-usable program code to access the i th element in the geometric array by:
calculating a binary index for the i th element;
using a leftmost “1” of the binary index to find a slot that points to a specific block of elements containing the i th element; and
using bits to the right of the leftmost “1” to find a specific element in the specific block of elements that is the i th element.
8. The computer program product of claim 7 , wherein calculating the binary index for the i th element comprises:
adding 1 to i; and
representing i+1 as a binary value to generate the binary index.
9. The computer program product of claim 1 , wherein a null value in a slot indicates that no block of elements has been allocated to the slot.