examples: Make some example Host methods a bit more interesting
#include <evmc/helpers.h>
+#include <cstring>
+#include <map>
+
+/// The comparator for std::map<evmc_address, ...>.
+bool operator<(const evmc_address& a, const evmc_address& b)
+{
+ return std::memcmp(a.bytes, b.bytes, sizeof(a)) < 0;
+}
+
+/// The comparator for std::map<evmc_uint256be, ...>.
+bool operator<(const evmc_uint256be& a, const evmc_uint256be& b)
+{
+ return std::memcmp(a.bytes, b.bytes, sizeof(a)) < 0;
+}
+
+struct account
+{
+ evmc_uint256be balance = {};
+ size_t code_size = 0;
+ evmc_uint256be code_hash = {};
+ std::map<evmc_uint256be, evmc_uint256be> storage;
+};
+
struct example_host_context : evmc_context
{
example_host_context();
evmc_tx_context tx_context = {};
-};
-static evmc_uint256be balance(evmc_context* context, const evmc_address* address)
-{
- (void)context;
- (void)address;
- evmc_uint256be ret = {{1, 2, 3, 4}};
- return ret;
-}
+ std::map<evmc_address, account> accounts;
+};
static bool account_exists(evmc_context* context, const evmc_address* address)
{
- (void)context;
- (void)address;
- return false;
+ example_host_context* host = static_cast<example_host_context*>(context);
+ return host->accounts.find(*address) != host->accounts.end();
}
static void get_storage(evmc_uint256be* result,
@@ -56,15 +72,25 @@ static enum evmc_storage_status set_storage(evmc_context* context,
static bool get_balance(evmc_uint256be* result, evmc_context* context, const evmc_address* address)
{
- *result = balance(context, address);
+ example_host_context* host = static_cast<example_host_context*>(context);
+ auto it = host->accounts.find(*address);
+ if (it != host->accounts.end())
+ {
+ *result = it->second.balance;
return true;
}
+ return false;
+}
static bool get_code_size(size_t* result, evmc_context* context, const evmc_address* address)
{
- (void)result;
- (void)context;
- (void)address;
+ example_host_context* host = static_cast<example_host_context*>(context);
+ auto it = host->accounts.find(*address);
+ if (it != host->accounts.end())
+ {
+ *result = it->second.code_size;
+ return true;
+ }
return false;
}
@@ -72,9 +98,13 @@ static bool get_code_hash(evmc_uint256be* result,
evmc_context* context,
const evmc_address* address)
{
- (void)result;
- (void)context;
- (void)address;
+ example_host_context* host = static_cast<example_host_context*>(context);
+ auto it = host->accounts.find(*address);
+ if (it != host->accounts.end())
+ {
+ *result = it->second.code_hash;
+ return true;
+ }
return false;
}
