Add vector utility functions

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/vector.c b/vector.c
new file mode 100644
index 0000000..0863908
--- a/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;
+}