1 files changed, 112 insertions, 0 deletions
diff --git a/src/basic/alloc-util.c b/src/basic/alloc-util.c
new file mode 100644
index 0000000..bad15cc
--- /dev/null
+++ b/src/basic/alloc-util.c
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <malloc.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "macro.h"
+#include "memory-util.h"
+
+void* memdup(const void *p, size_t l) {
+        void *ret;
+
+        assert(l == 0 || p);
+
+        ret = malloc(l ?: 1);
+        if (!ret)
+                return NULL;
+
+        memcpy(ret, p, l);
+        return ret;
+}
+
+void* memdup_suffix0(const void *p, size_t l) {
+        void *ret;
+
+        assert(l == 0 || p);
+
+        /* The same as memdup() but place a safety NUL byte after the allocated memory */
+
+        if (_unlikely_(l == SIZE_MAX)) /* prevent overflow */
+                return NULL;
+
+        ret = malloc(l + 1);
+        if (!ret)
+                return NULL;
+
+        *((uint8_t*) mempcpy(ret, p, l)) = 0;
+        return ret;
+}
+
+void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size) {
+        size_t a, newalloc;
+        void *q;
+
+        assert(p);
+        assert(allocated);
+
+        if (*allocated >= need)
+                return *p;
+
+        if (_unlikely_(need > SIZE_MAX/2)) /* Overflow check */
+                return NULL;
+
+        newalloc = need * 2;
+        if (size_multiply_overflow(newalloc, size))
+                return NULL;
+
+        a = newalloc * size;
+        if (a < 64) /* Allocate at least 64 bytes */
+                a = 64;
+
+        q = realloc(*p, a);
+        if (!q)
+                return NULL;
+
+        if (size > 0) {
+                size_t bn;
+
+                /* Adjust for the 64 byte minimum */
+                newalloc = a / size;
+
+                bn = malloc_usable_size(q) / size;
+                if (bn > newalloc) {
+                        void *qq;
+
+                        /* The actual size allocated is larger than what we asked for. Let's call realloc() again to
+                         * take possession of the extra space. This should be cheap, since libc doesn't have to move
+                         * the memory for this. */
+
+                        qq = reallocarray(q, bn, size);
+                        if (_likely_(qq)) {
+                                *p = qq;
+                                *allocated = bn;
+                                return qq;
+                        }
+                }
+        }
+
+        *p = q;
+        *allocated = newalloc;
+        return q;
+}
+
+void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size) {
+        size_t prev;
+        uint8_t *q;
+
+        assert(p);
+        assert(allocated);
+
+        prev = *allocated;
+
+        q = greedy_realloc(p, allocated, need, size);
+        if (!q)
+                return NULL;
+
+        if (*allocated > prev)
+                memzero(q + prev * size, (*allocated - prev) * size);
+
+        return q;
+}