Add vector utility functions

[ps-cgit] / vector.c

diff --git a/vector.c b/vector.c
new file mode 100644 (file)
index 0000000..0863908
--- /dev/null
+++ b/vector.c
@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include "vector.h"
+
+static int grow(struct vector *vec, int gently)
+{
+       size_t new_alloc;
+       void *new_data;
+
+       new_alloc = vec->alloc * 3 / 2;
+       if (!new_alloc)
+               new_alloc = 8;
+       new_data = realloc(vec->data, new_alloc * vec->size);
+       if (!new_data) {
+               if (gently)
+                       return ENOMEM;
+               perror("vector.c:grow()");
+               exit(1);
+       }
+       vec->data = new_data;
+       vec->alloc = new_alloc;
+       return 0;
+}
+
+int vector_push(struct vector *vec, const void *data, int gently)
+{
+       int rc;
+
+       if (vec->count == vec->alloc && (rc = grow(vec, gently)))
+               return rc;
+       if (data)
+               memmove(vec->data + vec->count * vec->size, data, vec->size);
+       else
+               memset(vec->data + vec->count * vec->size, 0, vec->size);
+       vec->count++;
+       return 0;
+}