Difference between revisions of "ListSpace.c"
(remove prototypes) |
(add malloc) |
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Line 1: | Line 1: | ||
− | + | // Allocate memory for maximum ListItems | |
− | + | space = calloc(MAXITEMS*3, sizeof(int)); | |
− | + | printf("%d bytes of memory allocated\n", MAXITEMS*3*sizeof(int)); | |
− | + | ||
− | + | // Create a new listItem in the space and return its index | |
+ | int listInsert() { | ||
+ | //printf("listInsert(): new item %d\n", items); | ||
+ | return items++; | ||
+ | } | ||
− | + | // Start at subject listItem and traverse the object as an association to a new listItem | |
− | + | // - object is also a listItem reference and its binary address is used as the traversal path | |
− | + | // - subject and object (all list-item references are ints starting at item 0) | |
− | + | int listTraverse(int subject, int object) { | |
− | + | object += 2; // tmp: can't traverse items 0 or 1 | |
− | + | int i; | |
− | + | for ( i = 1; i <= object >> 1; i <<= 1 ) { | |
− | + | int *addr = space + subject * 3 + (object & i ? 1 : 0); | |
− | + | subject = *addr ? *addr : (*addr = listInsert()); | |
− | |||
− | |||
} | } | ||
+ | return subject; | ||
+ | } | ||
− | + | // Get the value (payload key) of the subject Item | |
− | + | int listGetValue(int subject) { | |
− | + | int *addr = space + subject * 3 + 2; | |
− | + | return *addr; | |
− | + | } | |
− | + | // Set the payload key of the subject Item to the passed value | |
− | + | void listSetValue(int subject, int value) { | |
− | + | int *addr = space + subject * 3 + 2; | |
− | + | *addr = value; | |
− | + | } |
Revision as of 04:34, 2 July 2006
// Allocate memory for maximum ListItems space = calloc(MAXITEMS*3, sizeof(int)); printf("%d bytes of memory allocated\n", MAXITEMS*3*sizeof(int));
// Create a new listItem in the space and return its index int listInsert() { //printf("listInsert(): new item %d\n", items); return items++; }
// Start at subject listItem and traverse the object as an association to a new listItem // - object is also a listItem reference and its binary address is used as the traversal path // - subject and object (all list-item references are ints starting at item 0) int listTraverse(int subject, int object) { object += 2; // tmp: can't traverse items 0 or 1 int i; for ( i = 1; i <= object >> 1; i <<= 1 ) { int *addr = space + subject * 3 + (object & i ? 1 : 0); subject = *addr ? *addr : (*addr = listInsert()); } return subject; }
// Get the value (payload key) of the subject Item int listGetValue(int subject) { int *addr = space + subject * 3 + 2; return *addr; }
// Set the payload key of the subject Item to the passed value void listSetValue(int subject, int value) { int *addr = space + subject * 3 + 2; *addr = value; }