cosmwasm: Add simple token contract example

examples/cosmwasm_simple_token/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(cosmwasm_simple_token)
+
+find_package(blanc)
+
+# TODO: Separate cosmwasm toolchain configuration
+include(EosioWasmToolchain)
+
+add_executable(token ${CMAKE_CURRENT_SOURCE_DIR}/src/token.cpp)
+
+target_include_directories(token PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+
+# TODO: Add a convenient way to set build profile
+target_compile_options(token PUBLIC --profile=cosmwasm)
+target_link_options(token PUBLIC --profile=cosmwasm)
+

examples/cosmwasm_simple_token/include/token.hpp

@@ -0,0 +1,54 @@
+#pragma once
+#include <cosmwasm/serialize.hpp>
+
+struct token {
+   std::string address;
+   uint128_t amount;
+
+   COSMWASM_SERIALIZE(token, (address)(amount))
+};
+
+struct instantiate_msg {
+   std::string name;
+   std::string symbol;
+   uint8_t decimals;
+   std::vector<token> initial_balances;
+
+   COSMWASM_SERIALIZE(instantiate_msg, (name)(symbol)(decimals)(initial_balances))
+};
+
+struct transfer_msg {
+   std::string recipient;
+   uint128_t amount;
+
+   COSMWASM_SERIALIZE2(transfer_msg, "transfer", (recipient)(amount))
+};
+
+using execute_msg = std::variant<transfer_msg>;
+
+struct balance_msg {
+   std::string address;
+
+   COSMWASM_SERIALIZE2(balance_msg, "balance", (address))
+};
+
+struct token_info_msg {
+   COSMWASM_SERIALIZE2(token_info_msg, "token_info")
+};
+
+using query_msg = std::variant<balance_msg,token_info_msg>;
+
+struct balance_response {
+   uint128_t balance;
+
+   COSMWASM_SERIALIZE(balance_response, (balance))
+};
+
+struct token_info_response {
+   std::string name;
+   std::string symbol;
+   uint8_t decimals;
+   uint128_t total_supply;
+
+   COSMWASM_SERIALIZE(token_info_response, (name)(symbol)(decimals)(total_supply))
+};

examples/cosmwasm_simple_token/src/token.cpp

@@ -0,0 +1,140 @@
+#include <cosmwasm/cosmwasm.hpp>
+#include "token.hpp"
+
+using namespace cosmwasm;
+
+class token_contract : public contract {
+public:
+   using contract::contract;
+
+   void instantiate(
+      const std::string& name,
+      const std::string& symbol,
+      uint8_t decimals,
+      std::vector<token> initial_balances
+   ) {
+      auto total_supply = create_accounts(initial_balances);
+      _storage.set(
+         namespaces_with_key({}, to_bytes("token_info")),
+         token_info_response {
+            name, symbol, decimals, total_supply
+         }.as_bytes()
+      );
+   }
+
+   void transfer(const std::string& recipient, uint128_t amount) {
+      auto address = addr_validate(recipient);
+      sub_balance(_info.sender, amount);
+      add_balance(address, amount);
+   }
+
+   bytes get_balance(const std::string& address) {
+      balance_response bres = { 0 };
+
+      auto s = _storage.get(namespaces_with_key({to_bytes("balance")}, to_bytes(address)));
+      if (s) {
+         bres.balance = from_bytes<uint128_t>(*s);
+      }
+
+      return to_bytes(bres);
+   }
+
+   bytes get_token_info() {
+      return *_storage.get(namespaces_with_key({}, to_bytes("token_info")));
+   }
+
+
+private:
+   void add_balance(const std::string& address, const uint128_t& amount) {
+      uint128_t balance = 0;
+
+      auto key = namespaces_with_key({to_bytes("balance")}, to_bytes(address));
+      auto s = _storage.get(key);
+      if (s) {
+         balance = from_bytes<uint128_t>(*s);
+      }
+
+      uint128_t new_balance = balance + amount;
+      check(new_balance > balance);
+      _storage.set(key, to_bytes(new_balance));
+   }
+
+   void sub_balance(const std::string& address, const uint128_t& amount) {
+      uint128_t balance = 0;
+
+      auto key = namespaces_with_key({to_bytes("balance")}, to_bytes(address));
+      auto s = _storage.get(key);
+      if (s) {
+         balance = from_bytes<uint128_t>(*s);
+      }
+
+      uint128_t new_balance = balance - amount;
+      check(new_balance < balance);
+      _storage.set(key, to_bytes(new_balance));
+   }
+
+   uint128_t create_accounts(const std::vector<token>& accounts) {
+      uint128_t total_supply = 0;
+      for (const auto& acc : accounts) {
+         total_supply += acc.amount;
+         auto address = addr_validate(acc.address);
+         add_balance(address, acc.amount);
+      }
+      return total_supply;
+   }
+};
+
+
+extern "C" {
+   [[clang::export_name("instantiate")]]
+   region* instantiate(region* env_ptr, region* info_ptr, region* msg_ptr) {
+      contract_result<response> res;
+
+      auto e = json::from_region<cosmwasm::env>(env_ptr);
+      auto i = json::from_region<cosmwasm::message_info>(info_ptr);
+      auto m = json::from_region<instantiate_msg>(msg_ptr);
+      auto c = token_contract(e, i);
+
+      c.instantiate(m.name, m.symbol, m.decimals, m.initial_balances);
+
+      return json::to_region(res).release();
+   }
+
+   [[clang::export_name("execute")]]
+   region* execute(region* env_ptr, region* info_ptr, region* msg_ptr) {
+      contract_result<response> res;
+
+      auto e = json::from_region<cosmwasm::env>(env_ptr);
+      auto i = json::from_region<cosmwasm::message_info>(info_ptr);
+      auto m = json::from_region<execute_msg>(msg_ptr);
+      auto c = token_contract(e, i);
+
+      std::visit(overloaded {
+         [&](const transfer_msg& msg) {
+            c.transfer(msg.recipient, msg.amount);
+            res.ok.attributes.push_back({"action", "transfer"});
+            res.ok.attributes.push_back({"from", i.sender});
+            res.ok.attributes.push_back({"to", msg.recipient});
+            res.ok.attributes.push_back({"amount", std::to_string(msg.amount)});
+         },
+      }, m);
+
+      return json::to_region(res).release();
+   }
+
+   [[clang::export_name("query")]]
+   region* query(region* env_ptr, region* msg_ptr) {
+      contract_result<bytes> res;
+
+      auto e = json::from_region<cosmwasm::env>(env_ptr);
+      auto m = json::from_region<query_msg>(msg_ptr);
+      auto c = token_contract(e, {});
+
+      std::visit(overloaded {
+         [&](balance_msg& msg) { res.ok = c.get_balance(msg.address); },
+         [&](token_info_msg& msg) { res.ok = c.get_token_info(); },
+      }, m);
+
+      return json::to_region(res).release();
+   }
+}