gaddag*
parse_gaddag(const char* filename)
{
// Instantiate the root GADDAG
gaddag* root_gaddag = create_gaddag();
// Open the input file handle
FILE* fp = fopen(filename, "r");
if (fp == 0)
{
fprintf(stderr, "Filename %s is invalid. Please try again.\n", filename);
}
char* linebuf = (char*) malloc(LONGEST_LINE_LENGTH * sizeof(char));
memset(linebuf, 0, LONGEST_LINE_LENGTH);
// For each line
while (fscanf(fp, "%s", linebuf) != EOF)
{
// prepare it (uppercase + strip),
format_string_for_gaddag(linebuf);
// split into representations.
char* representations = split_into_representations(linebuf);
// add to the Gaddag
add_to_gaddag(root_gaddag, linebuf, representations);
memset(linebuf, 0, LONGEST_LINE_LENGTH);
free(representations);
}
free(linebuf);
fclose(fp);
return root_gaddag;
}
void
add_to_gaddag(gaddag* root, const char* str, const char* representations)
{
const unsigned length = strlen(str);
const unsigned rep_length = length + 1;
gaddag* working_gaddag = root;
unsigned row, col;
for (row = 0; row < length; ++row)
{
for (col = 0; col < rep_length; ++col)
{
const unsigned index = (row * rep_length) + col;
const char key = representations[index];
unsigned offset = offset_from_key(key);
gaddag* branch = working_gaddag->ptrs[offset];
if (!branch)
{
// If the key isn't present, create a new node.
gaddag* new_node = create_gaddag();
// Link it to this one.
*(working_gaddag->ptrs + offset) = new_node;
// set this to the working gaddag, and continue the loop.
working_gaddag = new_node;
}
else
{
// If the key exists.
// trace it, continue the loop.
working_gaddag = branch;
}
}
set_terminator(working_gaddag);
working_gaddag = root;
}
}
