METHOD FOR ALLOCATING MEMORY SPACE
The present invention concerns a method for allocating a space of predetermined size in a memory ( 2 ) of a smart card ( 1 ), characterized in that it comprises steps of: deterministic preselection ( 100 ) in the memory ( 2 ), of at least one free zone having a size larger than the predetermined size, selection, ( 104 ) in a preselected free zone of a sub-zone having a size equal to the predetermined size, the selection of the sub-zone being variable for one same preselected free zone, use ( 106 ) of the selected sub-zone as allocated memory space.
1 . A method for allocating a space of predetermined size in a memory of a smart card, wherein it comprises steps of:
preselecting in the memory at least one free zone having a size larger than the predetermined size using a deterministic policy;
selecting in the preselected free zone a sub-zone having a size equal to the predetermined size, wherein selecting the sub-zone is variable for one same preselected free zone;
use of the selected sub-zone as allocated memory space.
2 . The method according to claim 1 , wherein the sub-zone is selected from among several candidate sub-zones included in the preselected free zone, wherein a first candidate sub-zone thereof has a start address equal to the start address of the selected free zone.
3 . The method according to claim 1 , wherein the sub-zone is selected from among several candidate sub-zones included in the preselected free zone, wherein a second candidate sub-zone thereof has an end address equal to the end address of the selected free zone.
4 . The method according to claim 1 , wherein the sub-zone is selected from among several candidate sub-zones included in the preselected free zone, wherein a third candidate sub-zone thereof has a start address strictly higher than the start address of the selected free zone, and has an end address strictly lower than the end address of the selected free zone.
5 . The method according to claim 1 , wherein the sub-zone is selected from a group of candidate sub-zones having start addresses offset from one another by only one octet in the preselected zone.
6 . The method according to claim 2 , wherein the sub-zone is selected from among several candidate sub-zones included in the preselected free zone, wherein a second candidate sub-zone thereof has an end address equal to the start address of the selected free zone, wherein the candidate sub-zones consist of the first sub-zone and second sub-zone only.
7 . The method according to claim 1 , wherein the sub-zone is selected randomly in the selected free zone.
9 . The method according to claim 1 , wherein the selected free zone is contiguous and/or wherein the reserved sub-zone is contiguous.
10 . The method according to claim 1 , wherein the deterministic policy is of “best-fit” type.
11 . The method according to claim 1 , wherein the deterministic policy is of “next fit” type.
12 . The method according to claim 1 , wherein the deterministic policy is of “first-fit” type.
13 . The method according to claim 1 wherein, if the several free zones are preselected, then selecting the sub-zone is conducted in a free zone selected randomly or pseudo-randomly from among the preselected free zones.
14 . A computer program product comprising program code instructions to execute the steps of the allocation method according to claim 1 , when this program is executed by at least one processor.
15 . A smart card comprising:
at least one memory,
at least one processor configured to execute the computer program product according to claim 14 , for the purpose of allocating space in the memory.