Writing procedure, updating and memory allocation applied to writing files in a storage medium such as a chip card

摘要

Method of writing and updating a file (FTS) written in a storage medium using two file descriptors, file comprising a number of registers (E1, E2, E3) of certain sizes, having for object a part of these records (E2, E3) updated data (d4, d5) new, replacing data (d2, d3) old, assigning a certain number of spaces (A0, A1, A2, A3, A4) memory memory support to write the log data file, determining the position of each memory space being written data for each log file in a memory space between the memory spaces assigned to be written first descriptor (ITS1) file in the memory support, referencing the file descriptor in the order of the records in the file, memory spaces between memory spaces allocated to enable it determine what memory space asig wave data of each record in the file is written, outnumbering memory spaces assigned the total number of records in the file, the number of memory spaces in excess at least equal to the maximum number of records of a group susceptible records be updated simultaneously during a write operation, the method comprising the following steps: - the file descriptor read, - are derived from it spaces (A0, A2) allocated memory free, - the data (d4, d5 are written ) new in memory spaces between memory spaces allocated free, - then we write a new descriptor (ITS2) file in the storage medium, referencing the new descriptor spaces (A0, A2) memory in which data (d4, d5) are written rather new spaces (A1, A4) memory in which data are written (d2, d3) old - the first descriptor is kept in memory fiche ro, - in each subsequent update operation file, write a new file descriptor instead of the oldest of the two file descriptors descriptor.