initial implementation of wasm interface for transaction contract api ref EOSIO/eos#175

contracts/eoslib/transaction.h

@@ -58,6 +58,8 @@ extern "C" {
 
    typedef uint32_t TransactionHandle;
    #define InvalidTransactionHandle (0xFFFFFFFFUL)
+   #define SendInline (1)
+   #define SendDeferred (0)
 
    /**
     * @brief create a pending transaction
@@ -103,9 +105,10 @@ extern "C" {
     * This function adds a @ref PermissionName to the pending message
     *
     * @param trx - the `TransactionHandle` of the pending transaction to modify
+    * @param account - the `AccountName` to add
     * @param permission - the `PermissionName` to add
     */
-   void transactionAddMessagePermission(TransactionHandle trx, PermissionName permission);
+   void transactionAddMessagePermission(TransactionHandle trx, AccountName account, PermissionName permission);
 
 
    /**
@@ -147,7 +150,7 @@ extern "C" {
     * @param trx - the `TransactionHandle` of the pending transaction to send
     * @param inlineMode - whether to send as an inline transaction (!=0) or deferred(=0)
     */
-   void transactionSend(TransactionHandle trx, int inlineMode = 0);
+   void transactionSend(TransactionHandle trx, int mode = SendDeferred);
 
    /**
     * @brief drop a pending transaction

libraries/chain/include/eos/chain/exceptions.hpp

@@ -57,6 +57,8 @@ namespace eos { namespace chain {
    FC_DECLARE_DERIVED_EXCEPTION( tx_duplicate,                      eos::chain::transaction_exception, 3030011, "duplicate transaction" )
    FC_DECLARE_DERIVED_EXCEPTION( unknown_transaction_exception,     eos::chain::transaction_exception, 3030012, "unknown transaction" )
    FC_DECLARE_DERIVED_EXCEPTION( tx_scheduling_exception,           eos::chain::transaction_exception, 3030013, "transaction failed during sheduling" )
+   FC_DECLARE_DERIVED_EXCEPTION( tx_unknown_argument,               eos::chain::transaction_exception, 3030014, "transaction provided an unknown value to a system call" )
+   FC_DECLARE_DERIVED_EXCEPTION( tx_resource_exhausted,             eos::chain::transaction_exception, 3030015, "transaction exhausted allowed resources" )
 
    FC_DECLARE_DERIVED_EXCEPTION( invalid_pts_address,               eos::chain::utility_exception, 3060001, "invalid pts address" )
    FC_DECLARE_DERIVED_EXCEPTION( insufficient_feeds,                eos::chain::chain_exception, 37006, "insufficient feeds" )

libraries/chain/include/eos/chain/message_handling_contexts.hpp

@@ -19,7 +19,8 @@ public:
                  const chain::Message& m,
                  const types::AccountName& code)
       : controller(con), db(db), trx(t), msg(m), code(code), mutable_controller(con),
-        mutable_db(db), used_authorizations(msg.authorization.size(), false){}
+        mutable_db(db), used_authorizations(msg.authorization.size(), false),
+        next_pending_transaction_serial(0){}
 
    template <typename ObjectType>
    int32_t store_record( Name scope, Name code, Name table, typename ObjectType::key_type* keys, char* value, uint32_t valuelen ) {
@@ -286,11 +287,49 @@ public:
    chainbase::database& mutable_db;
 
    std::deque<AccountName>          notified;
-   std::deque<ProcessedTransaction> sync_transactions; ///< sync calls made
-   std::deque<GeneratedTransaction> async_transactions; ///< async calls requested
+   std::deque<Transaction>          inline_transactions; ///< queued inline txs
+   std::deque<Transaction>          deferred_transactions; ///< deferred txs
 
    ///< Parallel to msg.authorization; tracks which permissions have been used while processing the message
    vector<bool> used_authorizations;
+
+   ///< pending transaction construction
+   typedef uint32_t pending_transaction_handle;
+   struct pending_transaction {
+      typedef uint32_t handle_type;
+      static const handle_type Invalid_handle = 0xFFFFFFFFUL;
+
+      handle_type handle;
+      struct message_dest {
+         AccountName code;
+         FuncName type;
+      };
+
+      // state set that applies to pushed message data
+      optional<message_destination> current_destination;
+      vector<types::AccountPermission> current_permissions;
+
+      // state to apply when the transaction is pushed
+      vector<AccountName> scopes;
+      vector<AccountName> read_scopes;
+      vector<types::Message> messages;
+
+      types::Transaction as_transaction() const;
+      void check_size() const;
+
+      void reset_message() {
+         current_destination = decltype(current_destination)();
+         current_permissions.clear();
+      }
+   };
+
+   pending_transaction::handle_type next_pending_transaction_serial;
+   vector<pending_transaction> pending_transactions;
+
+   pending_transaction& get_pending_transaction(pending_transaction::handle_type handle);
+   pending_transaction& create_pending_transaction();
+   void release_pending_transaction(pending_transaction::handle_type handle);
+
 };
 
 using apply_handler = std::function<void(apply_context&)>;

libraries/chain/message_handling_contexts.cpp

@@ -51,4 +51,49 @@ vector<types::AccountPermission> apply_context::unused_authorizations() const {
    return {range.begin(), range.end()};
 }
 
+pending_transaction& apply_context::get_pending_transaction(pending_transaction::handle_type handle) {
+   auto itr = boost::find_if(pending_transactions, [&](const auto& trx) { return trx.handle == handle; });
+   EOS_ASSERT(itr != pending_transactions.end(), tx_unknown_argument,
+              "Transaction refers to non-existant/destroyed pending transaction");
+   return *itr;
+}
+
+const int Max_pending_transactions = 4;
+const uint32_t Max_pending_transaction_size = 16 * 1024;
+const auto Pending_transaction_expiration = fc::seconds(21 * 3); 
+
+pending_transaction& apply_context::create_pending_transaction() {
+   EOS_ASSERT(pending_transactions.size() < Max_pending_transactions, tx_resource_exhausted,
+              "Transaction is attempting to create too many pending transactions. The max is ${max}", ("max", Max_pending_transactions));)
+   
+   pending_transaction::handle handle = next_pending_transaction_serial++;
+   pending_transactions.push_back({handle});
+   return pending_transaction.back();
+}
+
+void apply_context::release_pending_transaction(pending_transaction::handle_type handle) {
+   auto itr = boost::find_if(pending_transactions, [&](const auto& trx) { return trx.handle == handle; });
+   EOS_ASSERT(itr != pending_transactions.end(), tx_unknown_argument,
+              "Transaction refers to non-existant/destroyed pending transaction");
+
+   auto last = pending_transactions.end() - 1;
+   if (itr != last) {
+      std::swap(itr, last);
+   }
+   pending_transactions.pop_back();
+}
+
+types::Transaction apply_context::pending_transaction::as_transaction() const {
+   decltype(types::Transaction::refBlockNum) head_block_num = chain_controller.head_block_num();
+   decltype(types::Transaction::refBlockRef) head_block_ref = fc::endian_reverse_u32(chain_controller.head_block_ref()._hash[0]);
+   decltype(types::Transaction::expiration) expiration = chain_controller.head_block_time() + Pending_transaction_expiration;
+   return types::Transaction(head_block_num, head_block_ref, expiration, scopes, read_scopes, messages);
+}
+
+void apply_context::pending_transaction::check_size() const {
+   auto trx = as_transaction();
+   EOS_ASSERT(fc::raw::pack_size(trx) <= Max_pending_transaction_size, tx_resource_exhausted,
+              "Transaction is attempting to create a transaction which is too large. The max size is ${max} bytes", ("max", Max_pending_transaction_size));
+}
+
 } } // namespace eos::chain

libraries/chain/wasm_interface.cpp

@@ -241,39 +241,98 @@ DEFINE_INTRINSIC_FUNCTION3(env,memcpy,memcpy,i32,i32,dstp,i32,srcp,i32,len) {
 }
 
 
-DEFINE_INTRINSIC_FUNCTION2(env,send,send,i32,i32,trx_buffer, i32,trx_buffer_size ) {
+/**
+ * Transaction C API implementation
+ * @{
+ */ 
+
+static const uint32_t InvalidTransactionHandle = 0xFFFFFFFFUL;
+
+DEFINE_INTRINSIC_FUNCTION0(env,transactionCreate,transactionCreate,i32) {
+   auto& ptrx = wasm_interface::get().current_apply_context->create_pending_transaction();
+   return ptrx.handle;
+}
+
+DEFINE_INTRINSIC_FUNCTION3(env,transactionAddScope,transactionAddScope,none,i32,handle,i64,scope,i32,readOnly) {
+   auto& ptrx = wasm_interface::get().current_apply_context->get_pending_transaction(handle);
+   if(readOnly == 0) {
+      ptrx.scopes.emplace_back(scope);
+   } else {
+      ptrx.read_scopes.emplace_back(scope);
+   }
+
+   ptrx.check_size();
+}
+
+DEFINE_INTRINSIC_FUNCTION3(env,transactionSetMessageDestination,transactionSetMessageDestination,none,i32,handle,i64,code,i64,type) {
+   auto& ptrx = wasm_interface::get().current_apply_context->get_pending_transaction(handle);
+   ptrx.current_destination = decltype(ptrx.current_destination)({Name(code), Name(type)});
+}
+
+DEFINE_INTRINSIC_FUNCTION3(env,transactionAddMessagePermission,transactionAddMessagePermission,none,i32,handle,i64,account,i64,permission) {
+   wasm_interface::get().current_apply_context->require_authorization(Name(account), Name(permission));
+   auto& ptrx = wasm_interface::get().current_apply_context->get_pending_transaction(handle);
+   ptrx.current_permissions.emplace_back(Name(account), Name(permission));
+}
+
+DEFINE_INTRINSIC_FUNCTION3(env,transactionPushMessage,transactionPushMessage,none,i32,handle,i32,msg_buffer,i32,msg_size) {
    auto& wasm  = wasm_interface::get();
    auto  mem   = wasm.current_memory;
-   const char* buffer = &memoryRef<const char>( mem, trx_buffer );
 
-   FC_ASSERT( trx_buffer_size > 0 );
-   FC_ASSERT( wasm.current_apply_context, "not in apply context" );
+   EOS_ASSERT( msg_size > 0, tx_unknown_argument
+      "Attempting to push an empty message" );
 
-   fc::datastream<const char*> ds(buffer, trx_buffer_size );
-   eos::chain::GeneratedTransaction gtrx;
-   eos::chain::Transaction& trx = gtrx;
-   fc::raw::unpack( ds, trx );
+   const char* buffer = nullptr; 
+   try {
+      // memoryArrayPtr checks that the entire array of bytes is valid and
+      // within the bounds of the memory segment so that transactions cannot pass
+      // bad values in attempts to read improper memory
+      buffer = memoryArrayPtr<const char>( mem, msg_buffer, msg_size );
+   } catch( const Runtime::Exception& e ) {
+      FC_THROW_EXCEPTION(tx_unknown_argument, "Message data is not valid");
+   }
 
-/**
- *  The code below this section provides sanity checks that the generated message is well formed
- *  before being accepted. These checks do not need to be applied during reindex.
- */
-#warning TODO: reserve per-thread static memory for MAX TRX SIZE 
-/** make sure that packing what we just unpacked produces expected output */
-   auto test = fc::raw::pack( trx );
-   FC_ASSERT( 0 == memcmp( buffer, test.data(), test.size() ) );
+   auto& ptrx = wasm.current_apply_context->get_pending_transaction(handle);
+   EOS_ASSERT(ptrx.destination.valid(), tx_unknown_argument
+      "Attempting to push a message without setting a destination");
+
+   auto& dest = *ptrx.destination;
+   ptrx.messages.emplace_back(dest.code, dest.type, ptrx.current_permissions, Bytes(buffer, buffer + msg_size));
+   ptrx.reset_message();
+   ptrx.check_size();
+}
+
+DEFINE_INTRINSIC_FUNCTION1(env,transactionResetMessage,transactionResetMessage,none,i32,handle) {
+   auto& ptrx = wasm_interface::get().current_apply_context->get_pending_transaction(handle);
+   ptrx.reset_message();
+}
 
-/** TODO: make sure that we can call validate() on the message and it passes, this is thread safe and
- *   ensures the type is properly registered and can be deserialized... one issue is that this could
- *   construct a RECURSIVE virtual machine state which means the wasm_interface state needs to be a STACK vs
- *   a per-thread global.
- **/
+DEFINE_INTRINSIC_FUNCTION2(env,transactionSend,transactionSend,none,i32,handle,i32,mode) {
+   EOS_ASSERT(mode == 0 || mode == 1, tx_unknown_argument
+      "Unknown delivery mode when sending transaction: ${mode}", ("mode":mode));
 
-//   wasm.current_apply_context->generated.emplace_back( std::move(gtrx) );
+   auto apply_context  = wasm_interface::get().current_apply_context;
+   auto& ptrx = apply_context->get_pending_transaction(handle);
 
-   return 0;
+   EOS_ASSERT(ptrx.messages.size() > 0, , tx_unknown_argument
+      "Attempting to send a transaction with no messages");
+
+   if (mode == 0) {
+      apply_context->deferred_transactions.emplace_back(ptrx.as_transaction());
+   } else {
+      apply_context->inline_transactions.emplace_back(ptrx.as_transaction());
+   }
+
+   apply_context->release_pending_transaction(handle);
 }
 
+DEFINE_INTRINSIC_FUNCTION1(env,transactionDrop,transactionDrop,none,i32,handle) {
+   wasm_interface::get().current_apply_context->release_pending_transaction(handle);
+}
+
+/**
+ * @} Transaction C API implementation
+ */