tx mempool start, hello packet

include/utils.h

@@ -6,6 +6,23 @@
 #include <string.h>
 #include <stdbool.h>
 
+typedef struct {
+    uint8_t bytes[32];
+} key32_t;
+
+static inline uint32_t hash_key32(key32_t k) {
+    uint32_t hash = 2166136261u;
+    for (int i = 0; i < 32; i++) {
+        hash ^= k.bytes[i];
+        hash *= 16777619;
+    }
+    return hash;
+}
+
+static inline int eq_key32(key32_t a, key32_t b) {
+    return memcmp(a.bytes, b.bytes, 32) == 0;
+}
+
 static inline void AddressToHexString(const uint8_t address[32], char out[65]) {
     if (!address || !out) {
         return;