Tail *
tail_open (const char *path, const char *name, TrieIOMode mode)
{
Tail *t;
TrieIndex i;
uint16 sig;
long file_size;
t = (Tail *) malloc (sizeof (Tail));
t->file = file_open (path, name, ".tl", mode);
if (!t->file)
goto exit1;
file_size = file_length (t->file);
if (file_size != 0 && file_read_int16 (t->file, (int16 *) &sig)
&& sig != TAIL_SIGNATURE)
{
goto exit2;
}
/* init tails data */
if (file_size == 0) {
t->first_free = 0;
t->num_tails = 0;
t->tails = NULL;
t->is_dirty = TRUE;
} else {
file_read_int16 (t->file, &t->first_free);
file_read_int16 (t->file, &t->num_tails);
t->tails = (TailBlock *) malloc (t->num_tails * sizeof (TailBlock));
if (!t->tails)
goto exit2;
for (i = 0; i < t->num_tails; i++) {
int8 length;
file_read_int16 (t->file, &t->tails[i].next_free);
file_read_int16 (t->file, &t->tails[i].data);
file_read_int8 (t->file, &length);
t->tails[i].suffix = (TrieChar *) malloc (length + 1);
if (length > 0)
file_read_chars (t->file, (char *)t->tails[i].suffix, length);
t->tails[i].suffix[length] = '\0';
}
t->is_dirty = FALSE;
}
return t;
exit2:
fclose (t->file);
exit1:
free (t);
return NULL;
}
Tail *
tail_read (FILE *file)
{
long save_pos;
Tail *t;
TrieIndex i;
uint32 sig;
/* check signature */
save_pos = ftell (file);
if (!file_read_int32 (file, (int32 *) &sig) || TAIL_SIGNATURE != sig)
goto exit_file_read;
if (NULL == (t = (Tail *) malloc (sizeof (Tail))))
goto exit_file_read;
if (!file_read_int32 (file, &t->first_free) ||
!file_read_int32 (file, &t->num_tails))
{
goto exit_tail_created;
}
if (t->num_tails > SIZE_MAX / sizeof (TailBlock))
goto exit_tail_created;
t->tails = (TailBlock *) malloc (t->num_tails * sizeof (TailBlock));
if (!t->tails)
goto exit_tail_created;
for (i = 0; i < t->num_tails; i++) {
int16 length;
if (!file_read_int32 (file, &t->tails[i].next_free) ||
!file_read_int32 (file, &t->tails[i].data) ||
!file_read_int16 (file, &length))
{
goto exit_in_loop;
}
t->tails[i].suffix = (TrieChar *) malloc (length + 1);
if (length > 0) {
if (!file_read_chars (file, (char *)t->tails[i].suffix, length)) {
free (t->tails[i].suffix);
goto exit_in_loop;
}
}
t->tails[i].suffix[length] = '\0';
}
return t;
exit_in_loop:
while (i > 0) {
free (t->tails[--i].suffix);
}
free (t->tails);
exit_tail_created:
free (t);
exit_file_read:
fseek (file, save_pos, SEEK_SET);
return NULL;
}
