dmmlib/block_header.c

#include "block_header.h"

block_header_t * get_header(void *ptr);

block_header_t * get_header(void *ptr) {
    return (block_header_t *) ((char *) ptr - HEADER_SIZE);
}

void * get_next(void *ptr) {
    return get_header(ptr)->next;
}

size_t get_size(void *ptr) {
    return get_header(ptr)->size;
}

void set_size(void *ptr, size_t size) {
    get_header(ptr)->size = size << 1;
}

void set_requested_size(void *ptr, size_t size) {
    get_header(ptr)->requested_size = size;
}

void set_next(void *ptr, void *next_block) {
    get_header(ptr)->next = next_block;
}

bool is_previous_free(void *ptr) {
    return (bool) (get_header(ptr)->previous_size & 1);
}

size_t get_previous_size(void *ptr) {
    return get_header(ptr)->previous_size >> 1;
}

void * get_previous(void *ptr) {
    return (void *) ((char *) ptr - get_previous_size(ptr));
}

void remove_block(void *block, void *starting_node) {
    void *current_node, *previous_node;

    // If the block to be removed is the head of the list, then just point
    // the next block as head.
    if(current_node == starting_node) {
        starting_node = get_next(block);
        // Else traverse through the list until the memory block is found.
    } else {
        for(current_node = starting_node; current_node != NULL; 
                current_node = get_next(current_node)) {
            if(current_node == block) {
                set_next(previous_node, get_next(block));
            }
            previous_node = current_node;
        }
    }
}