/* slang_atom_pool */
-void slang_atom_pool_construct (slang_atom_pool *pool)
+void
+slang_atom_pool_construct(slang_atom_pool * pool)
{
- GLuint i;
+ GLuint i;
- for (i = 0; i < SLANG_ATOM_POOL_SIZE; i++)
- pool->entries[i] = NULL;
+ for (i = 0; i < SLANG_ATOM_POOL_SIZE; i++)
+ pool->entries[i] = NULL;
}
-void slang_atom_pool_destruct (slang_atom_pool *pool)
+void
+slang_atom_pool_destruct (slang_atom_pool * pool)
{
- GLuint i;
+ GLuint i;
- for (i = 0; i < SLANG_ATOM_POOL_SIZE; i++)
- {
- slang_atom_entry *entry;
+ for (i = 0; i < SLANG_ATOM_POOL_SIZE; i++) {
+ slang_atom_entry * entry;
- entry = pool->entries[i];
- while (entry != NULL)
- {
- slang_atom_entry *next;
-
- next = entry->next;
- slang_alloc_free (entry->id);
- slang_alloc_free (entry);
- entry = next;
+ entry = pool->entries[i];
+ while (entry != NULL) {
+ slang_atom_entry *next;
+
+ next = entry->next;
+ slang_alloc_free(entry->id);
+ slang_alloc_free(entry);
+ entry = next;
}
}
}
-/**
- * Search atom pool for atom with the given name.
- * If name is not found, create new atom (but don't insert into pool?)
+/*
+ * Search the atom pool for an atom with a given name.
+ * If atom is not found, create and add it to the pool.
+ * Returns ATOM_NULL if the atom was not found and the function failed to create a new atom.
*/
-slang_atom slang_atom_pool_atom (const slang_atom_pool *pool, const char *id)
+slang_atom
+slang_atom_pool_atom(slang_atom_pool * pool, const char * id)
{
- GLuint hash;
- const char *p = id;
- slang_atom_entry * const * entry;
- slang_atom_entry **newEntry = NULL;
-
- hash = 0;
- while (*p != '\0')
- {
- GLuint g;
-
- hash = (hash << 4) + (GLuint) *p++;
- g = hash & 0xf0000000;
- if (g != 0)
- hash ^= g >> 24;
- hash &= ~g;
- }
- hash %= SLANG_ATOM_POOL_SIZE;
-
- entry = &pool->entries[hash];
- while (*entry != NULL)
- {
- if (slang_string_compare ((**entry).id, id) == 0)
- return (slang_atom) (**entry).id;
- entry = &(**entry).next;
- }
-
- *newEntry = (slang_atom_entry *) slang_alloc_malloc (sizeof (slang_atom_entry));
- if (*newEntry == NULL)
- return SLANG_ATOM_NULL;
+ GLuint hash;
+ const char * p = id;
+ slang_atom_entry ** entry;
+
+ /* Hash a given string to a number in the range [0, ATOM_POOL_SIZE). */
+ hash = 0;
+ while (*p != '\0') {
+ GLuint g;
+
+ hash = (hash << 4) + (GLuint) (*p++);
+ g = hash & 0xf0000000;
+ if (g != 0)
+ hash ^= g >> 24;
+ hash &= ~g;
+ }
+ hash %= SLANG_ATOM_POOL_SIZE;
+
+ /* Now the hash points to a linked list of atoms with names that have the same hash value.
+ * Search the linked list for a given name. */
+ entry = &pool->entries[hash];
+ while (*entry != NULL) {
+ /* If the same, return the associated atom. */
+ if (slang_string_compare((**entry).id, id) == 0)
+ return (slang_atom) (**entry).id;
+ /* Grab the next atom in the linked list. */
+ entry = &(**entry).next;
+ }
- (**newEntry).next = NULL;
- (**newEntry).id = slang_string_duplicate (id);
- if ((**newEntry).id == NULL)
- return SLANG_ATOM_NULL;
- return (slang_atom) (**newEntry).id;
+ /* Okay, we have not found an atom. Create a new entry for it.
+ * Note that the <entry> points to the last entry's <next> field. */
+ *entry = (slang_atom_entry *) (slang_alloc_malloc(sizeof(slang_atom_entry)));
+ if (*entry == NULL)
+ return SLANG_ATOM_NULL;
+
+ /* Initialize a new entry. Because we'll need the actual name of the atom, we use the pointer
+ * to this string as an actual atom's value. */
+ (**entry).next = NULL;
+ (**entry).id = slang_string_duplicate(id);
+ if ((**entry).id == NULL)
+ return SLANG_ATOM_NULL;
+ return (slang_atom) (**entry).id;
}
-const char *slang_atom_pool_id (slang_atom_pool *pool, slang_atom atom)
+/*
+ * Return the name of a given atom.
+ */
+const char *
+slang_atom_pool_id(slang_atom_pool * pool, slang_atom atom)
{
- return (const char *) atom;
+ return (const char *) (atom);
}
+
+/**
+ * Generate a new, unique atom with given prefix.
+ */
+slang_atom
+slang_atom_pool_gen(slang_atom_pool * pool, const char *prefix)
+{
+ char name[1000];
+ static int nextFree = 100;
+ sprintf(name, "%s%d", prefix, nextFree);
+ nextFree++;
+ return slang_atom_pool_atom(pool, name);
+}