1 files changed, 88 insertions, 0 deletions
diff --git a/src/sysupdate/sysupdate-cache.c b/src/sysupdate/sysupdate-cache.c
new file mode 100644
index 0000000..8dad3ee
--- /dev/null
+++ b/src/sysupdate/sysupdate-cache.c
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "memory-util.h"
+#include "sysupdate-cache.h"
+
+#define WEB_CACHE_ENTRIES_MAX 64U
+#define WEB_CACHE_ITEM_SIZE_MAX (64U*1024U*1024U)
+
+static WebCacheItem* web_cache_item_free(WebCacheItem *i) {
+        if (!i)
+                return NULL;
+
+        free(i->url);
+        return mfree(i);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(WebCacheItem*, web_cache_item_free);
+
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(web_cache_hash_ops, char, string_hash_func, string_compare_func, WebCacheItem, web_cache_item_free);
+
+int web_cache_add_item(
+                Hashmap **web_cache,
+                const char *url,
+                bool verified,
+                const void *data,
+                size_t size) {
+
+        _cleanup_(web_cache_item_freep) WebCacheItem *item = NULL;
+        _cleanup_free_ char *u = NULL;
+        int r;
+
+        assert(web_cache);
+        assert(url);
+        assert(data || size == 0);
+
+        if (size > WEB_CACHE_ITEM_SIZE_MAX)
+                return -E2BIG;
+
+        item = web_cache_get_item(*web_cache, url, verified);
+        if (item && memcmp_nn(item->data, item->size, data, size) == 0)
+                return 0;
+
+        if (hashmap_size(*web_cache) >= (size_t) (WEB_CACHE_ENTRIES_MAX + !!hashmap_get(*web_cache, url)))
+                return -ENOSPC;
+
+        r = hashmap_ensure_allocated(web_cache, &web_cache_hash_ops);
+        if (r < 0)
+                return r;
+
+        u = strdup(url);
+        if (!u)
+                return -ENOMEM;
+
+        item = malloc(offsetof(WebCacheItem, data) + size + 1);
+        if (!item)
+                return -ENOMEM;
+
+        *item = (WebCacheItem) {
+                .url = TAKE_PTR(u),
+                .size = size,
+                .verified = verified,
+        };
+
+        /* Just to be extra paranoid, let's NUL terminate the downloaded buffer */
+        *(uint8_t*) mempcpy(item->data, data, size) = 0;
+
+        web_cache_item_free(hashmap_remove(*web_cache, url));
+
+        r = hashmap_put(*web_cache, item->url, item);
+        if (r < 0)
+                return r;
+
+        TAKE_PTR(item);
+        return 1;
+}
+
+WebCacheItem* web_cache_get_item(Hashmap *web_cache, const char *url, bool verified) {
+        WebCacheItem *i;
+
+        i = hashmap_get(web_cache, url);
+        if (!i)
+                return NULL;
+
+        if (i->verified != verified)
+                return NULL;
+
+        return i;
+}