add km_init(), refactor existing init

1 files changed, 80 insertions, 0 deletions

diff --git a/km-init.c b/km-init.c
new file mode 100644
index 0000000..f04fca0
--- /dev/null
+++ b/km-init.c
@@ -0,0 +1,80 @@
+#include <stdbool.h> // bool
+#include <stddef.h> // size_t
+#include <string.h> // strcmp()
+#include "util.h"
+#include "km.h"
+
+typedef bool (*km_init_fn_t)(
+  km_set_t *,
+  const size_t,
+  const km_set_t *,
+  km_rand_t *
+);
+
+bool km_init_rand(km_set_t *, const size_t, const km_set_t *, km_rand_t *);
+bool km_init_forgy(km_set_t *, const size_t, const km_set_t *, km_rand_t *);
+
+static const struct {
+  const km_init_type_t type;
+  const char * const name;
+  const km_init_fn_t init;
+} TYPES[] = {{
+  .name = "rand",
+  .type = KM_INIT_TYPE_RAND,
+  .init = km_init_rand,
+}, {
+  .name = "forgy",
+  .type = KM_INIT_TYPE_FORGY,
+  .init = km_init_forgy,
+}};
+
+#define NUM_TYPES (sizeof(TYPES) / sizeof(TYPES[0]))
+
+km_init_type_t
+km_init_get_type(
+  const char * const s
+) {
+  // find init method
+  for (size_t i = 0; i < NUM_TYPES; i++) {
+    if (!strcmp(s, TYPES[i].name)) {
+      // return type
+      return TYPES[i].type;
+    }
+  }
+
+  // return failure
+  return KM_INIT_TYPE_LAST;
+}
+
+static km_init_fn_t
+get_init_func(
+  const km_init_type_t type
+) {
+  // find init method
+  for (size_t i = 0; i < NUM_TYPES; i++) {
+    if (type == TYPES[i].type) {
+      // return init func
+      return TYPES[i].init;
+    }
+  }
+
+  // return failure
+  return NULL;
+}
+
+bool
+km_init(
+  km_set_t * const cs,
+  const km_init_type_t init_type,
+  const size_t num_clusters,
+  const km_set_t * const set,
+  km_rand_t * const rs
+) {
+  km_init_fn_t init_fn = get_init_func(init_type);
+  if (!init_fn) {
+    die("unknown cluster init method");
+  }
+
+  // call init, return result
+  return init_fn(cs, num_clusters, set, rs);
+}