Initialize

ms.c

@@ -0,0 +1,110 @@
+#include "dat.h"
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+
+void
+ms_init(Ms *a, ms_event_fn oninsert, ms_event_fn onremove)
+{
+    a->len = a->cap = a->last = 0;
+    a->items = NULL;
+    a->oninsert = oninsert;
+    a->onremove = onremove;
+}
+
+static int
+grow(Ms *a)
+{
+    void **nitems;
+    size_t ncap = a->cap << 1;
+    if (!ncap)
+        ncap = 1;
+
+    nitems = malloc(ncap * sizeof(void *));
+    if (!nitems)
+        return 0;
+
+    memcpy(nitems, a->items, a->len * sizeof(void *));
+    free(a->items);
+    a->items = nitems;
+    a->cap = ncap;
+    return 1;
+}
+
+int
+ms_append(Ms *a, void *item)
+{
+    if (a->len >= a->cap && !grow(a))
+        return 0;
+
+    a->items[a->len++] = item;
+    if (a->oninsert)
+        a->oninsert(a, item, a->len - 1);
+    return 1;
+}
+
+static int
+ms_delete(Ms *a, size_t i)
+{
+    void *item;
+
+    if (i >= a->len)
+        return 0;
+    item = a->items[i];
+    a->items[i] = a->items[--a->len];
+
+    /* it has already been removed now */
+    if (a->onremove)
+        a->onremove(a, item, i);
+    return 1;
+}
+
+void
+ms_clear(Ms *a)
+{
+    while (ms_delete(a, 0));
+    free(a->items);
+    ms_init(a, a->oninsert, a->onremove);
+}
+
+int
+ms_remove(Ms *a, void *item)
+{
+    size_t i;
+
+    for (i = 0; i < a->len; i++) {
+        if (a->items[i] == item)
+            return ms_delete(a, i);
+    }
+    return 0;
+}
+
+int
+ms_contains(Ms *a, void *item)
+{
+    size_t i;
+
+    for (i = 0; i < a->len; i++) {
+        if (a->items[i] == item)
+            return 1;
+    }
+    return 0;
+}
+
+void *
+ms_take(Ms *a)
+{
+    void *item;
+
+    if (!a->len)
+        return NULL;
+
+    // The result of last behaviour is that ms_take returns the oldest elements
+    // first, exception is a row of multiple take calls without inserts on ms
+    // of even number of elements. See the test.
+    a->last = a->last % a->len;
+    item = a->items[a->last];
+    ms_delete(a, a->last);
+    ++a->last;
+    return item;
+}