P2P: save/load onion peers, added onion seed nodes

src/util.h

@@ -400,6 +400,49 @@ FORCEINLINE void secure_zero_memory(T& value)
 std::string to_onion_v3(const hash& pubkey);
 hash from_onion_v3(const std::string& address);
 
+static FORCEINLINE constexpr hash from_onion_v3_const(const char* address)
+{
+	uint8_t buf[HASH_SIZE + 4] = {};
+	uint8_t* p = buf;
+
+	uint64_t data = 0;
+	uint64_t bit_size = 0;
+
+	for (size_t i = 0; i < 56; ++i) {
+		const char c = address[i];
+		uint64_t digit = 0;
+
+		if ('a' <= c && c <= 'z') {
+			digit = static_cast<uint64_t>(c - 'a');
+		}
+		else if ('A' <= c && c <= 'Z') {
+			digit = static_cast<uint64_t>(c - 'A');
+		}
+		else if ('2' <= c && c <= '7') {
+			digit = static_cast<uint64_t>(c - '2') + 26;
+		}
+		else {
+			return {};
+		}
+
+		data = (data << 5) | digit;
+		bit_size += 5;
+
+		while (bit_size >= 8) {
+			bit_size -= 8;
+			*(p++) = static_cast<uint8_t>(data >> bit_size);
+		}
+	}
+
+	hash result;
+
+	for (size_t i = 0; i < HASH_SIZE; ++i) {
+		result.h[i] = buf[i];
+	}
+
+	return result;
+}
+
 } // namespace p2pool
 
 void memory_tracking_start();