All notable changes to this project will be documented in this file. The project adheres to Semantic Versioning.

• Functionality of the proposer module was extended. Now, it can also be used for removing transactions from the pool of unconfirmed transactions. The module was renamed to pool and related names were updated accordingly. (#1840)

• Added a possibility to set max allowed json payload size in node.toml config file in api section (e.g. json_payload_size = 1048576). (#1918)

• It is now possible cache results of transaction correctness verification, which leads to a moderate improvement in node performance. (#1844)

• Backtrace is now included into ExecutionErrors. (#1850)

• Added a possibility to use domain names along with IP addresses on generation configs stage and in the connect list. (#1870)

• Inner rocksdb database has been replaced for in-memory data structure in TemporaryDB. (#1872)

• ApiManagerConfig was made non-exhaustive. (#1834)

• Exonum nodes now gracefully terminate on receiving SIGINT, SIGTERM and SIGQUIT signals (on Unix platforms), or a ctrl + c break (on Windows). These signal handlers may be switched off by using NodeBuilder::disable_signals(). (#1834)

• Fixed bug in run-dev command. Previously, using the existing configuration files in blockchain-path led to an error. (#1827)

• create_patch and commit methods in BlockchainMut have been generalized to support block skipping (see New Features section for more details). (#1820)

• run-dev command has been reworked. It now does not clear database files after the launch. artifacts-dir parameter has been renamed to blockchain-path. Configuration files are now stored inside config subdirectory. (#1822)

• MigrationRequest was made non-exhaustive. (#1823)

• POST endpoints now expect JSON-encoded input rather than hex-encoded Protobuf. (#1823)

• supervisor_name method was removed. Use Supervisor::NAME instead. (#1823)

• Several constants in the command module became public. (#1821)

• Exonum nodes can now customize how they create block proposals. This can be used to whitelist / blacklist transaction authors or services, prioritize transactions by advanced criteria, implement complex rate limiting, etc. The functionality is available via pool module. (#1820)

• Exonum nodes can now skip block generation at a certain epoch of the consensus algorithm. This can be used to keep a "heartbeat" when the network load is low without bloating the storage used by the nodes. (#1820)

• ServiceApiScope::pb_endpoint_mut allows to accept Protobuf-encoded messages with the request content type set to application/octet-stream in addition to JSON-encoded messages. (#1829)

• Testkit can send Protobuf-encoded payloads to POST endpoints. (#1831)

• Introduced a workaround for the HTTP restart hanging up on Windows. (#1828)

• Fixed a bug when a node created a propose with incorrect transactions. This could lead to consensus failure or weird error messages in the node log. (#1820)

• Fixed updating HTTP endpoints if the Rust runtime does not contain active services during node start. (#1831)

• DeployRequest and MigrationRequest now have cryptographic seeds to retry the same request multiple times. (#1823)

• Error handling is now performed with the anyhow crate instead of failure. (#1805)

• APIs which previously used futures from the futures 0.1 crate are now made async, or are using Futures from the standard library. (#1796, #1804) The main affected APIs are as follows:

  • Endpoint definitions in the exonum-api crate and their counterparts in exonum-rust-runtime
  • Transaction sending with ApiSender from the exonum crate
  • Node start-up with Node::run (exonum-node crate) and NodeBuilder::run (exonum-cli crate), and shutdown with ShutdownHandle (exonum-node crate)
  • HTTP API testing with TestKitApi (exonum-testkit crate)

• Testkit now does not include incorrect transactions into blocks or memory pool, similar to real Exonum nodes. (#1785)

• Runtime::deploy_artifact no longer returns Box<dyn Future<...>>. Instead a special communication channel is used to send deployment status from the runtime to the dispatcher. (#1788)

• Schema::call_errors was removed in favor of more comprehensive call_records method. (#1792)

• Blockchain::create_patch and Blockchain::commit signatures were changed due to unsoundness of the previous implementation; see "Bug Fixes" section for more details. (#1809)

• Replaced CoreError::ServiceNotStopped with the more general InvalidServiceTransition error. (#1806)

• Data types were made non-exhaustive where appropriate. (#1799)

• NodeBuilder was refactored to use a more intuitive set of interfaces for adding built-in artifacts and services to the blockchain. (#1800)
• Submodules of the command module were made private; the relevant data types are now exported from the command module directly. Similarly, io module was made private. (#1799)

• Data types were made non-exhaustive where appropriate. (#1799)

• impl_binary_value_for_pb_message macro was removed. Use the BinaryValue derive macro from the exonum-derive crate instead. (#1805)

• Data types were made non-exhaustive where appropriate. (#1799)

• Data types were made non-exhaustive where appropriate. (#1799)

• Public api module has been removed. List of endpoints from private api has been changed. (#1790) Current list of the endpoints:

  • v1/info - obtains information about the node;
  • v1/stats - obtains statistics of the node;
  • v1/peers - adds a peer to the Exonum node;
  • v1/consensus_status - enables or disables consensus on the node;
  • v1/shutdown - shuts down the node.

• API data types were made non-exhaustive where appropriate. (#1799)

• TestKitBuilder was refactored to use a more intuitive set of interfaces for adding built-in artifacts and services to the blockchain. (#1800)

• Data types were made non-exhaustive where appropriate. (#1799)

• Exonum now supports service freezing. A frozen service has fixed state (i.e., does not process transactions and service hooks), but, unlike stopped services, the service HTTP API remains active. (#1780)

• Core and the explorer service now support retrieving call status with a cryptographic proof of authenticity. (#1792)

• Exonum now supports unloading of unused service artifacts. This operation may be used to free resources associated with artifacts in the runtime hosting them. (#1794)

• Supervisor service supports service freezing. (#1781)

• supervisor/services endpoint has been added which obtains information about deployed artifacts and available services. (#1790)

• Supervisor service supports artifact unloading. (#1798)

• Rust services support freezing. (#1780)

• HTTP API of Rust services is now switched on during data migrations. (#1780)

• Testkit server now returns info on emulated nodes. (#1799)

• Core now provides more thorough / context-dependent error descriptions related to service lifecycle. (#1806)

• Index clearing now uses range deletions for RocksDB, providing a significant performance boost for this operation. (#1791)

• Fixed bug related to nodes forgetting transactions after executing a block with them. Previously, nodes forgot all transactions in the executed blocks; such transactions were removed from the ephemeral transaction cache, but were not flushed to the DB or anywhere else. This could lead to consensus hang-up. (#1809)

• Fixed potential node hang-up if the node received a proposal and a supermajority of transactions approving it before all transactions in the proposal are known. (#1781)

• Switched off broadcasting of transactions which the node considers incorrect. (#1781)

• Fixed incorrect invalidation of block proposals. (#1782)

• Provided clear coherence period for the transaction pool by introducing the mempool.flush_config_strategy configuration parameter. Previously, transactions were flushed to the persistent pool only on block commit. This led to the unexpected behavior of some APIs, such as the transaction getter endpoint in the explorer service. (#1809)

• Fixed race condition when two nodes try to establish outgoing connections to each other at the same time. (#1804)

• Testkit now does not include incorrect transactions into blocks or memory pool, similar to real Exonum nodes. (#1785)

• Added a method to get reference to the underlying API client for the TestKitApi. (#1811)

• before_commit hook was renamed to the after_transactions. (#1577)

• before_transactions and after_transactions hooks in Rust services now return a Result. The semantics is the same as for transactions; an error or panic in the hook will lead to the rollback of the blockchain state. (#1576)

• Errors occurring while executing transactions and before_transactions / after_transactions hooks are now aggregated within each block, rather than globally. Errors can be retrieved using BlockWithTransactions. (#1576)

• The Rust interface and Protobuf presentation of ExecutionError have been reworked. Error fields were made private and information about a failing call was added. (#1585)

• IntoExecutionError macro was reworked into a separate trait, ExecutionFail, and a corresponding derive macro. (#1585)

• State hash aggregation is now performed automatically by MerkleDB. The relevant methods in Runtime and Service in Rust runtime have been removed. (#1553)

• commit_service has been renamed to the update_service_status and now takes InstanceStatus as an additional argument. start_adding_service has been renamed to initiate_adding_service to better distinguish between starting and stopping a service. (#1605)

• after_transactions hook is now invoked on the genesis block for the builtin services. Note that calling blockchain::Schema::height within after_transactions hook will cause a panic for a builtin service. (#1619)

• proposer_id field in Block has been moved to additional block headers. (#1602)

• Interaction with services from the Rust runtime has been changed. Instead of using the Transaction trait, it is now possible to use service interfaces directly as Rust traits. These interface traits can be applied to a keypair (to generate signed transactions), to CallContext (to call another service) and some other types. See Rust runtime docs for more details. (#1606)

• The following public APIs were removed/made private: (#1629, #1671)

  • blockchain::{error reexports} (available from runtime::);
  • blockchain::FatalError public re-export;
  • blockchain::InstanceCollection structure;
  • Blockchain::pool_size, Blockchain::get_saved_peers and Blockchain::remove_peer_with_pubkey methods;
  • helpers::path_relative_from function;
  • helpers::ZeroizeOnDrop trait;
  • helpers::Milliseconds type;
  • helpers::config and helpers::user_agent modules;
  • helpers::generate_testnet_config, helpers::create_rust_runtime_and_genesis_config and helpers::clear_consensus_messages_cache functions;
  • impl_serde_hex_for_binary_value macro (moved to merkledb);
  • proto module;
  • runtime::error module (catch_panic was added to the list of public re-exports from runtime::error).

• node module and P2P messages from the message module (except for AnyTx and Precommit) were moved to a separate crate, exonum-node. The moved P2P messages were made private along with types / methods logically related to the consensus algorithm implementation (i.e., NodeHandler and types used by it). (#1698)

• The artifact identifier now has first-class semantic version. Previously, it was specific to the Rust runtime. (#1590)

• The name field of the artifact identifier cannot contain : symbol. (#1590)

• The format of the proto-sources endpoint in the Rust runtime has been changed. To get the core Protobuf sources, use the endpoint with the type=core query. To get the sources of an artifact, use query type=artifact&name=$name&version=$version, where $name and $version are replaced with appropriate values. (#1590)

• Rust runtime module was moved from the exonum crate into the separate exonum-rust-runtime crate. (#1641)

• update_service_status now does not return a value. (#1659)

• BlockchainBuilder::build now returns BlockchainMut instead of Result. (#1659)

• A type for a position of transaction in the block has been changed for u32. (#1668)

• DispatcherError has been split into two different types: CoreError and CommonError. (#1680)

• Common variant has been added to the ErrorKind enum. (#1680)

• api module of the exonum crate has been moved to 2 separate crates (#1690):

  • exonum-api crate defining the base HTTP wrapper
  • exonum-system-api crate implementing system API endpoints

• Added a new method initiate_resuming_service to the Runtime trait. This method is used to resume a previously stopped services. (#1693)

• ExecutionContext has been reworked (#1711)

  • ExecutionContext has been extended by the methods from the exonum_rust_runtime::CallContext so there is no need to use CallContext anymore. Public fields in ExecutionData has been replaced by the corresponding getters.
  • Direct fork access in ExecutionContext has been replaced by the BlockchainData::unstructured_access which returns readonly access to whole blockchain data.

• Public structures and enums were made non-exhaustive. (#1710)

• Blockchain data access from the ExecutionContext after an error in a nested call is prohibited. (#1733)

• Protobuf declarations were organized according to their packages and, in case of the exonum.runtime package, split into smaller chunks. The core messages were moved from exonum.messages to exonum package. (#1756)

• BlockchainBuilder now accepts GenesisConfig as a separate argument, rather than a part of new constructor. The config may be skipped if the blockchain is guaranteed to be initialized. (#1761)

• supervisor-mode parameter has been added for generate-template subcommand. (#1598)

• NodeBuilder::with_service has been renamed to the with_rust_service. (#1765)

• Protobuf declarations were organized according to their packages. (#1756)

• The field content of the CommittedTransaction struct and the InPool variant of the TransactionInfo enum has been renamed to message. (#1721)

• Supervisor structure isn't generic anymore. (#1587)

• DeployConfirmation structure was renamed to DeployResult and extended with success field. (#1648)

• Error code values were changed and split into several enum representing sub-groups. (#1680)

• The crate has been restructured, indexes are now located in separate module. Indexes iterators names has been shortened to Iter, Keys and Values. (#1628)

• SparseListIndex::indices method was renamed to SparseListIndex::indexes. (#1629)

• AccessExt::touch_index method has been replaced with index_type. (#1630)

• Public structures and enums were made non-exhaustive. (#1710)

• CopyAccessExt trait has been introduced. This trait is helpful for references implementing Access, such as &Fork or &dyn Snapshot. Methods from AccessExt trait accept self by reference now. (#1739)

• ProofPath serialization during map hash computations was unified. It now uses LEB128(bit_length) || bytes format, which was previously used for branches, but not for a single-entry maps. (#1743)

• Serialization of ProofPaths within MapProof Protobuf messages was changed to a more compact and implementation-independent format. (#1743)

• MapProof Protobuf messages now serialize keys according to their BinaryValue implementation, rather than BinaryKey. (#1743)

• All index types now share a common set of iterators: Entries, Keys and Values. (#1762)

• KeySetIndex::insert now takes the element by reference. (#1762)

• KeySetIndex now supports unsized keys. Its getter methods are no longer parameterized by the key type, similar to MapIndex / ProofMapIndex. (#1762)

• Protobuf declarations were organized according to their packages. (#1756)

• Service interfaces now have to specify method IDs with either interface_method attribute or auto_ids option. (#1701)

• Service interface methods now can be marked as removed. (#1707)

• The following public APIs were removed/made private: (#1629)

  • compare module;
  • txvec macro;
  • TestKit::probe_all and TestKit::probe methods.

• TestKitBuilder::create method was renamed to build. (#1740)

• TestNode now returns KeyPair instead of a (PublicKey, SecretKey) tuple. (#1761)

• Modules were made private, crate now provides re-exports of necessary types instead. (#1716)

• before_transactions hook for services was introduced. (#1577)

• ErrorMatch was introduced to test (e.g., using the testkit) that an ExecutionError has an expected type, error message and/or location. (#1585)

• We introduced a set of public endpoints to retrieve the status of calls executed within a block:

  • v1/call_status/transaction - gets the status of a transaction,
  • v1/call_status/before_transactions - gets the status of a before_transactions hook,
  • v1/call_status/after_transactions - gets the status of an after_transactions hook. (#1612)

• Service instances can now be stopped.

  Active service instance can be stopped by the corresponding request to the Supervisor. Stopped service no more participates in the business logic, i.e. it does not execute transactions, process events, provide user APIs, etc. Service data becomes unavailable to other services, but still exists. The name and identifier remain reserved for the stopped service and cannot be used again for adding new services. (#1605)

• New blockchain::Schema method next_height was added as a non-panicking alternative to height. (#1619)

• New method in_genesis_block was added to the CallContext to check if the service hook is being executed for the genesis block. (#1619)

• New api::Error variants were added: Gone and MovedPermanently. (#1607)

• API endpoints are now can be marked as deprecated. (#1607)

• Added ProtobufConvert for Verified, BlockProof and IndexProof. (#1643)

• Slash (/) is now allowed to be a part of artifact/instance name. (#1681)

• exonum-build now fully supports hierarchical paths to Protobuf files. (#1756)

• It is possible to opt out of including file sources into the output generated by the crate. (#1756)

• Blockchain::new now supports any type convertible to KeyPair. (#1761)

• Added maintenance command restart-migration to restart migration script. (#1728)

• Added with_instance and with_default_rust_service methods to NodeBuilder, which start service instances immediately after genesis block creation. (#1765)

• Added NodeBuilder::development_node constructor, which can be used to quickly set up a single-node development network. (#1765)

• KeyPair now can has constructors for generating a random keypair and generating a keypair from the specified seed. (#1761)

• MerkleDB now performs automated state aggregation allowing to construct proofs for its contents. Hashed indexes which are not a part of a group participate in this aggregation. Consult crate docs for more details on how aggregation works. (#1553)

• Added hashed version of Entry called ProofEntry, which participates in the state aggregation. (#1553)

• Added support of unsized keys to MapIndex and ProofMapIndex. (#1621, #1626)

• Added mechanism to extend block header. Block now contains key-value storage additional_headers which can contain binary data. (#1602)

• TemporaryDB can now be cleared. This will remove contents of all indexes and erase index metadata. (#1630)

• impl_serde_hex_for_binary_value macro was moved from core to merkledb. (#1629)

• It is now possible to iterate over keys of the indexes within a group. (#1662)

• Unsafe optimizations / experimental features are now behind a yolo feature, which is off by default. (#1740)

• MerkleDB now provides enumerations for all supported types of DB accesses which can be used to simplify generic code (e.g., in bindings). (#1747)

• It is now possible to obtain readonly access to fork data with static lifetime. (#1763)

• Node logic (including P2P networking and consensus algorithm) was moved from the exonum crate into the separate exonum-node crate. (#1698)

• Rust runtime module was moved from the exonum crate into the separate exonum-rust-runtime crate. (#1641)

• CallContext has been replaced by the ExecutionContext. (#1711)

• Supervisor service now can have initial configuration and implements Configure interface. (#1587)

• ConfigChange::StopService has been added to make requests to stop the service instance. (#1605)

• New private endpoint deploy-status was added. (#1648)

• Added support for resuming previously stopped services. (#1706)

  • Added resume_service method to the ConfigPropose.
  • Added ResumeService variant to the ConfigChange enumeration.

• Supervisor now supports migrations. (#1727)

• Added middleware service that can batch transactions and perform checked calls (calls that are executed if the target service corresponds to a specific artifact and version requirement). (#1590)

• sandbox module was moved to the test-suite/consensus-tests. (#1627)

• Some of general-purpose tests were moved to the test-suite/node-tests. (#1633)

• Snapshot implementation for Patch has been fixed. The previous implementation could lead to stale reads from a Patch or a Fork. (#1611)

• Maximum height in ProofListIndex was fixed from the bogus value 58 to 56. (#1762)

• Bogus setting of the empty key was removed for ListIndex. (#1762)

• ProofListIndex now properly processes all index values; previously, some of its methods panicked if called with an index exceeding 2 ** 56. (#1768)

• Most important: new Dynamic Services feature was introduced. For details see the Dynamic Services section of the changelog.

• Used rust version is updated to 1.38.0. (#1481)

• Transaction serialization format was changed to protobuf. (#1283)

• create_checkpoint method has been implemented for the RocksDB struct. This method uses RocksDB checkpoints functionality under the hood.

• NotFound error message for explorer/v1/block endpoint now includes the actual blockchain height. (#1498)

• system/v1/rebroadcast endpoint has been removed. (#1445)

• Added a possibility to specify compression algorithm for the database. (#1447)

• Updated hex dependency with changes in the methods signatures of the ToHex trait. (#1468)

• Validator keys are now derived from single master key. Master key is stored in encrypted file. (#1459)

• Command line parameters --service-key-pass and --consensus-key-pass was removed in favor of --master-key-pass parameter. For example now you can run the node with the command below. (#1459)

  cargo run -- run -d 0/db/ -c 0/node.toml --master-key-pass pass:123

  • StoppedTestKit::resume accepts list of runtimes instead of a list of services.

  • Removed obsolete TestKit::blockchain_mut method and TestKit::blockchain now returns value instead of reference.

• Dot symbol is not allowed in service names anymore. (#1558)

• Services can now use BlockchainData and SnapshotExt types to access data from the blockchain in a more structured manner. (#1523)

• GenesisConfig is extracted into separate entity. BlockchainBuilder, Node and Testkit explicitly accepts it during creation. (#1541)

• Added DefaultInstance trait for declaration of builtin services. (#1541)

• Nested proofs for ProofListIndex are replaced with a flat (non-recursive) format. (#1450)

• Differentiated (read-only / read-write) access to the database was introduced. (#1523)

• It is now possible to have readonly access to indexes given a Fork via a ReadonlyFork wrapper. Readonly access works like RefCell::borrow (vs RefCell::borrow_mut for Fork); it is possible to create an unlimited number of indexes with readonly access based on the same fork. (#1523)

• Service schemas can now use a declarative layout, in which every field corresponds to a separate index or a group of indexes. It is possible to derive a constructor for such schemas via FromAccess derive macro. (#1523, #1562)

• New index name restrictions has been added. (#1558)

  • Dot symbol is not allowed anymore in indexes with prefixed access.

  • Index names starting from __ and not containing a dot . are reserved and used only for system indexes.

• Introduced a new crate exonum-proto. Trait ProtobufConvert is moved to this crate. (#1496)

• Introduced a new crate exonum-protobuf-convert. Derive macro ProtobufConvert is moved to this crate. (#1501)

• Derive macro ProtobufConvert now does not derive the BinaryValue and ObjectHash traits. There are separate derive macros for them in the exonum-derive crate. (#1501)

• Method protobuf_generate is now private, use exonum_build::ProtobufGenerator instead (#1496).

• Method ProtobufGenerator::frequently_used has been removed (#1581).

• Methods read_keys_from_file and generate_keys are moved to new keys module in the exonum. (#1459)

• Protobuf serialization for crypto types is now implemented in the exonum-crypto crate. (#1496)

In exonum 0.13, a new service workflow is introduced, named "Dynamic Services".

Key points of this feature are the following:

• exonum now supports different environments of code execution (runtimes). Only native rust runtime is enabled by default, but support of different programming languages can be added quite easily.

  For details see the Runtime trait docs and the sample_runtime example.

• Services are not statically tied to the compiled binary anymore. There is support of adding new service types (aka artifacts) dynamically and starting new instances of services.

  For details see runtime module docs.

• Services now can have initialization parameters, provided within service start procedure.

• Services now support configuration changes via Configure interface.

• configuration service was replaced with the supervisor service, which is capable of not only changing configuration, but of deploying and starting services as well. For details see supervisor service.

There are a lot of backward-incompatible changes introduced within 0.13 release. So to make the changes apparent, compare the Cryptocurrency example service versions for 0.12.1 and 0.13.0 releases.

Key points:

• Merkledb schema is now declarative and can contain indices as fields.

• Access to the database is now isolated for services. A service cannot get the write access to another service or the blockchain schema.

• Transactions do not have the execute method anymore. Instead, a service defines and implements an interface trait which contains all the business logic.

• Services do not launch at the node start by default. For launching a service, use an exonum-launcher tool.

• New config params http_backend_config.server_restart_max_retries and http_backend_config.server_restart_retry_timeout added into NetworkConfiguration. They are intended to configure restart settings of the HTTP-server (#1536).

• exonum now has a python library for implementing integration tests. (#1516)

• BlockchainMut now has a check_tx method used to verify transactions before adding them to the transactions pool. Transactions for which check_tx fails are considered invalid and can't be included to the block. (#1579)

• ProofListIndex now implements truncate() and pop() methods, allowing to eject elements from the list. (#1455)

• IndexAccess trait is implemented for several new types, notably, Rc<dyn Snapshot>, Arc<dyn Snapshot> and Rc<Fork>. (#1455)

• HashTag::hash_list() was extended to support values of any appropriate type, not only Hash. (#1455)

• ProtobufConvert has been implemented for MapProof (#1512) and ListProof (#1513).

• New variant of the ProofMapIndex have been introduced - RawProofMapIndex. It is used for keys that maps directly to ProofPath, for example Hash and PublicKey. (#1531)

  • By default ProofMapIndex is used for keys that implement ObjectHash.

  • For Hash keys both map variants works the same, because ObjectHash implementation for Hash returns the hash itself.

• Old fabric module is replaced with new exonum-cli crate. (#1443)

• exonum-cli provides a public reexport of structopt crate. (#1461)

• system/v1/shutdown endpoint has been modified and now accepts empty POST requests. (#1526)

• exonum-protobuf-convert has been replaced with external protobuf-convert crate. (#1561)

• keys module has been moved into exonum-keys crate. (#1497)

• ProofListIndex::extend() method has been refactored, leading to up to 10x performance improvements for large lists. (#1455)

• Proofs building mechanisms have been heavily refactored. (#1460)

• Configuration change example has been moved to exonum-supervisor crate. (#1582)

• Now input directory is always added to includes to reduce boilerplate code. (#1581)

• Localhost ports 8080/8081 are now allowed in CORS within the run-dev mode. (#1415)

• index_metadata now correctly loads the provided index address name (#1478).

• A message length checking has been fixed (#1463)

• Module storage has been replace by exonum-merkledb crate. See related section

• Signatures of methods Service::initialize and Service::before_commit has been changed. Now they take immutable reference to Fork instead of mutable. (#1293)

• Trait BinaryForm has been replaced by BinaryValue. (#1298)

  To implement BinaryValue for types that implements Protobuf::Message use impl_binary_value_for_pb_message macros.

• Module storage has been replaced by exonum-merkledb crate. See related section in changelog for details. (#1293)

• Bootstrapping workflow has been simplified (#1292)

  generate-config subcommand now uses single OUTPUT_DIR instead of set of options. So to generate node config you should write something like example bellow.

  cargo run --bin exonum-timestamping -- \
    generate-template /tmp/exonum/template.toml --validators-count 4
  
  cargo run --bin exonum-timestamping -- \
    generate-config /tmp/exonum/template.toml /tmp/exonum/cfg/0 \
      --peer-address 0.0.0.0:8000
  cargo run --bin exonum-timestamping -- \
    generate-config /tmp/exonum/template.toml /tmp/exonum/cfg/1 \
      --peer-address 0.0.0.0:8001
  cargo run --bin exonum-timestamping -- \
    generate-config /tmp/exonum/template.toml /tmp/exonum/cfg/2 \
      --peer-address 0.0.0.0:8002
  cargo run --bin exonum-timestamping -- \
    generate-config /tmp/exonum/template.toml /tmp/exonum/cfg/3 \
      --peer-address 0.0.0.0:8003
  
  cargo run --bin exonum-timestamping -- \
    finalize /tmp/exonum/nodes/0/sec.toml /tmp/exonum/nodes/0/node.toml \
      --public-configs /tmp/exonum/cfg/{0,1,2,3}/pub.toml
  
  cargo run --bin exonum-timestamping -- \
    run -d /tmp/exonum/db/0 -c /tmp/exonum/nodes/0/node.toml

• explorer/v1/block endpoint returns a response in a "flat" format. (#1386)

• explorer/v1/blocks endpoint with add_blocks_time param switched on now returns median precommit times in the time field within each returned block, rather than in a separate array. (#1278)

• system/v1/mempool endpoint has been renamed into system/v1/stats. An additional field in the response of the endpoint was added. The field corresponds to the total number of transactions in the blockchain. (#1289)

• system/v1/mempool endpoint has been renamed into system/v1/stats. An additional field in the response of the endpoint was added. The field corresponds to the total number of transactions in the blockchain. (#1289)

• Added restrictions to index names. Allowable characters in index name: ASCII characters, digits, underscores and dashes. (#1388)

• Added Debug implementation for Database, Snapshot, Iterator dynamic traits (#1363)

• Changed storage layout (#1293)

  • Changed indexes metadata layout in the database.

  • Introduced a generic IndexState structure that can be used to store global index properties like total number of items.

• Changed ProofMapIndex hashing rules for branch nodes and root node. Branch nodes is hashing now with 0x04 prefix, root node with 0x03 (#1293).

• Renamed method merkle_root of ProofMapIndex and ProofListIndex to object_hash (#1293).

• Several mutable indexes now can be create from immutable reference to Fork (#1293)

• Relaxed trait bounds for the ProofMapIndex keys (#1293)

  Now keys should just implement BinaryKey trait instead of the ProofMapKey, which will be ordered according to their binary representation, as in the MapIndex.

• Changed ProofListIndex hashing rules for leaf nodes and branch nodes according to the certificate transparency specification. Leaf nodes contain hashes with 0x00 prefix, branch nodes - with 0x01. (#1293)

• StorageValue and StorageKey have been renamed to the BinaryValue and BinaryKey. (#1293)

  • Added to_bytes method to the BinaryValue trait which doesn't consume original value instead of the into_bytes.
  • BinaryKey::write now returns total number of written bytes.
  • CryptoHash has been replaced by the ObjectHash.

• Changed the hash algorithm of the intermediate nodes in ProofMapIndex. (#1293)

  ProofPath now uses compact binary representation in the BranchNode hash calculation.

  Binary representation is |bits_len|bytes|, where:

  • bits_len - total length of the given ProofPath in bits compressed by the leb128 algorithm
  • bytes - non-null bytes of the given ProofPath, i.e. the first (bits_len + 7) / 8 bytes.

• Removed deprecated CryptoHash trait, use exonum-merkledb::ObjectHash instead (#1361)

• New endpoint: v1/transactions/subscribe, which subscribe to new transaction events. This endpoint accept optional parameters: service_id and message_id (message_id as in derive macro TransactionSet). (#1335)

• New endpoint: v1/ws, which open websocket connection and allow to set multiple subscription (for blocks and transaction, filtered by service and transaction id) and send transactions (in hex, like in explorer) to blockchain (examples can be found in related pull request). (#1335)

• Fixed TestKit::add_tx() method, which previously did not persist transactions. (#1278)

• explorer/v1/blocks endpoint supports add_precommits param, which supplies each returned block with the precommits field. (#1278)

• explorer/v1/blocks endpoint allows to specify the lower bound on the returned block height with the earliest query param. (#1278)

• Added ProtobufConvert implementation for byte array with fixed sizes (#1279)

• Added service_name getter to the TransactionContext. (#1274)

• Allowed to use symbol - in index names. (#1277)

• rocksdb crate is now used instead of exonum_rocksdb. (#1286)

• Added a new endpoint system/v1/services for displaying information about available services. (#1288)

• Endpoints explorer/v1/block and explorer/v1/transactions were extended with adding additional fields service_id and time. (#1386)

• Added tx_cache field to State to cache incoming transactions before adding them to persistent pool. (#1398)

• Added new request message PoolTransactionsRequest to obtain pool transactions from another peers. (#1404)

• Endpoints explorer/v1/block and explorer/v1/transactions were extended with adding additional fields service_id and time. (#1386)

• Updated ProofMapIndex data layout. (#1293)

  Path to the root node in merkle patricia tree now has been stored in the index state.

• New API for getting and creating indexes. (#1293)

  • Now indexes can be accessed via immutable references from Snapshot and mutable/immutable references from Fork.

  • Introduced method fork::get_object to get or create object by address.

  • get_object_existed and get_object_existed_mut methods of Fork and Snapshot returns optional references to index.

• rocksdb crate is now used instead of exonum_rocksdb. (#1286)

• Added a new endpoint system/v1/services for displaying information about available services. (#1288)

• rocksdb crate is now used instead of exonum_rocksdb. (#1286)

• Added From<Patch> trait implementation to Fork. (#1403)

• Implemented "stopping" and "resuming" a TestKit, allowing to emulate node restarts. (#1278)

• Node secret keys are now stored in separate files in a secure way. CLI for generating node configs and starting nodes has been extended in order to reflect these changes. (#1222, #1096, #1235)

• Changed a response for /healthcheck endpoint. (#1252)

• Changed a response code for the /block endpoint for the case when the requested block doesn't exist. (#1262)

• Removed a sub-command generate-testnet from CLI. (#1264)

• Renamed create_keys_file function to generate_keys_file in utils module. (#1222, #1096)

• All Exonum crates have been updated to Rust 2018 edition. This means that it is required to use Rust 1.31 or newer for compilation. (#1230)

• Added allow-origin for localhost for public and private api in development mode by default. (#1234)

• Added ProtobufConvert implementation for Signature. (#1241)

• Unpin versions of dependencies. (#1237)

• Added i128/u128 support for StorageKey, StorageValue. (#1179)

• Added i128/u128 support for CryptoHash. (#1179)

• Dependencies have been updated. (#1111, #1162, #1167, #1168)

• ctrl+c handler has been added for correct node stopping. (#1163)

• pwbox dependency has been updated. (#1164)

• Changed the message format, which, in turn, has led to changes in the byte representation of transactions and precommit messages. (#916)

• Transaction::execute now accepts TransactionContext as the second parameter. TransactionContext provides the public key of transaction author, ID of current service, and transaction hash. (#943)

• Transaction::verify method has been removed. (#1085)

• Every transaction that contains the public key of the author was refactored to use the author indicated in TransactionContext. (#984 #980 #979 #975 #971)

• /transactions/ endpoint can now handle transaction messages in hex format. Services that used custom endpoints were refactored to use explorer/v1/transactions. (#943 #984 #980 #979 #975 #971)

• majority_count parameter has been moved from StoredConfiguration to ConfigurationService configuration. (#828)

• Removed obsolete enable_blockchain_explorer option from NodeApiConfig. (#891)

• Consensus messages and inner structs are now serialized with protobuf. (#1028)

• tx_pool_capacity parameter has been removed from MemoryPoolConfig. (#1036)

• Custom serialization has been removed. (#1088)

• Trait TransactionSend was removed. ApiSender now contains broadcast_transaction method. (#943)

• api::Error::InternalError now contains failure::Error instead of Box<::std::error::Error>. (#879)

• TransactionSend::send now returns Result<(), failure::Error> instead of io::Result. (#879)

• ApiSender methods send_external_message and peer_add now returns Result<(), failure::Error> instead of io::Result. (#879)

• majority_count parameter has been added to generate-template and generate-testnet commands. (#828)

• NodePrivateConfig fields have been renamed: listen_addr to listen_address and external_addr to external_address. (#809)

• NodePublicConfig addr field has been renamed to address. (#809)

• Config parameter external_address is now a required value. (#826)

• Config parameter round_timeout has been renamed to first_round_timeout. Now timeout for round r is first_round_timeout + (r-1)*round_timeout_increase, where round_timeout_increase is determined as a certain percentage of first_round_timeout. The value of this percentage is defined in ConsensusConfig::TIMEOUT_LINEAR_INCREASE_PERCENT constant (10%). (#848)

• missing_keys, entries, all_entries methods of CheckedMapProof and MapProof::missing_keys_unchecked method now return impl Iterator instead of Vec. (#918)

• Connect message field addr with SocketAddr has been removed, pub_addr with str of unresolved external address of the peer is used instead. (#942)

• Endpoint v1/peers now returns ConnectInfo in incoming connections instead of single IP-addresses. (#959)

• Fork::remove_by_prefix() method now specifies prefix as Option<&[u8]> instead of Option<&Vec<u8>>. (#1042)

• TransactionResult is now serialized using protobuf. Empty description of the result is now the equivalent of there being no description of the result. (#1075)

• Service::tx_from_raw now uses failure::Error as an error type. (#1088)

• transactions! macro has been removed, TransactionSet derive macro from exonum-derive should be used instead. (#1088)

• encoding_struct! macro has been removed, protobuf should be used instead. (#1088)

• Structures in tests and examples are serialized using protobuf now. (#1078)

• Structures in tests and examples are serialized using protobuf now. (#1081)

• Structures in tests and examples are serialized using protobuf now. (#1081)

• The Vote and VoteAgainst now save the transaction hash instead of full transaction message. (#984)

• Structures are serialized using protobuf now. (#1086)

• Structures are serialized using protobuf now. (#1086)

• Added utils module with functions create_keys_file for creating and read_keys_from_file for reading files that contain a public key and encrypted secret key. (#1056)

• Added possibility to use domain names instead of IP addresses as a peer's addresses. (#826)

• Added v1/rebroadcast endpoint that can be used to broadcast all transactions from the pool to other nodes. (#859)

• Now each consecutive round is longer than previous by some constant percentage of first_round_timeout. (#848)

• Added /v1/blocks/subscribe endpoint for following block commit events through WebSockets (#792).

• Added MapProof::all_entries_unchecked method. It is used for more efficient calculations in Exonum Java Bindings, but can be used for debug purposes as well. (#918)

• Added listen-address command line argument to specify different external address (peer-address) and listen address when generating config files. (#942)

• Peer address is resolved on connect instead of resolving on node startup. (#942)

• Now peers require only one connection to exchange messages between them. (#945)

• exonum-build crate has been added to simplify writing build.rs files for services that use protobuf code generation. (#1076)

• exonum-derive crate has been added with custom derives for ProtobufConvert and TransactionSet. (#1055)

• Bug with pool size overflow has been fixed. (#853)

• Bug in NoiseWrapper::decrypt_msg caused by wrong calculation of encrypted and decrypted message sizes has been fixed. (#873)

• Transactions (signature) verification benchmark has been fixed. (#673)

• Node no longer panics when transaction pool has a lot of transactions and consensus is at round 0. (#673)

• Node now works correctly after consensus re-enable via API. (#902)

• Bug with incorrect EOF handling while decoding network messages has been fixed. (#917)

• Bug leading to deletion of excessive data when clearing an index belonging to an index family has been fixed. (#1042)

• new_in_family index constructor introduced in #531 now accepts &str and &[u8] as an index_id value.

• NodeHandler::run_handler now returns Result<(), failure::Error> instead of io::Result. (#879)

• Transactions (signature) verification benchmark has been added. (#808)

• A new function storage::proof_list_index::root_hash() has been added to efficiently compute Merkle root hash from a list of hashes without an intermediate ProofListIndex. Verification of block root hashes has been optimized as well. (#802)

• NoiseHandshake::finalize now returns error if remote peer's public key is not in ConnectList. (#811)

• Now nodes will switch to min_propose_timeout for block proposal timeout faster if they receive more than propose_timeout_threshold transactions during max_propose_timeout. (#844)

• Custom log formatting (along with colored and term dependencies) has been removed in favor of env_logger. (#857).

• Several dependencies have been updated. (#861, #865, #871)

• Transactions are now verified in a thread pool. Thread pool size is set to optimal value by default (CPU count) or can be configured manually. (#673)

• The finalize command now does not include the node itself as its own trusted peer in the generated configuration. (#892)

• Added a possibility to create ServiceApiBuilder with blockchain. (#929)

• ConnectInfo and ConnectList now stores unresolved addresses as strings. (#942)

• Now network module uses PublicKeys to identify peers. (#942)

• system/v1/peers endpoint now properly returns incoming and outgoing connections of the node. (#942)

• A version of snow dependency has been updated.

• SegmentField implementation for Option has been added, allowing to store optional values inside of transactions. (#1004)

• Config parameter external_address is now a required value. (#826)

• Added possibility to use domain names instead of IP addresses as a peer's addresses. In config file domain names can be used in ConnectList configuration and addresses will be resolved once on startup. (#826)

• Added a possibility to create ServiceApiBuilder with blockchain. (#929)

• failure version has been updated to 0.1.2 in order to fix the build issue with failure_derive. (#845)

• Bug with "unknown propose" execution has been fixed. (#841)

• Command trait in helpers::fabric module became public. (#778)

  Migration path:

  If you override ServiceFactory::command method and do a match by a command name, just add use helpers::fabric::Command import.

• schema_version field in Block has been removed. (#774)

• Storage in exonum is now versioned. Old databases will not work with this update. (#707)

• Iron-based web API has been replaced by the new implementation based on actix-web. (#727)

  Migration path:

  For backend:

  • Remove old dependencies on iron and its companions bodyparser, router and others.

  • Simplify the API handlers as follows:

    fn my_handler(state: &ServiceApiState, query: MyQueryType)
    -> Result<MyResponse, ApiError>
    {
      // ...
    }

    where MyQueryType type implements Deserialize trait and MyResponse implements Serialize trait.

  • Replace old methods public_api_handler and private_api_handler of Service trait by a single wire_api method which takes ServiceApiBuilder. You can use this builder as a factory for your service API.

  • get, get_err and post methods in TestKitApi have been replaced by the more convenient RequestBuilder. Don't forget to update your testkit-based API tests.

  For frontend:

  • New API implementation supports only query parameters in GET requests. In this way requests like GET api/my_method/:first/:second should be replaced by the GET api/my_method?first=value1&second=value2.
  • JSON parser for POST requests is now more strict. In this way you should send null in request body even for handlers without query parameters.

  See our examples for more details.

• storage::base_index module has become private along with BaseIndex and BaseIndexIter types. (#723)

• ServiceFactory trait has been extended with service_name function.(#730)

• Method name has been removed from Run, GenerateCommonConfig, GenerateNodeConfig, Finalize, GenerateTestnet and Maintenance structures (helpers/fabric module). (#731)

• Whitelist has been replaced by ConnectList. Now connection between nodes can only be established if nodes exist in each other's connect lists. (#739)

  Migration path:

  • Replace [whitelist] section in config with [connect_list.peers] section and specify here all validators' consensus public keys with corresponding ip-addresses. For example 16ef83ca...da72 = "127.0.0.1:6333".

• Healthcheck and consensus endpoints (v1/healthcheck and v1/consensus_status) have been merged to v1/healthcheck. (#736, #766)

• Node configuration file is now updated at ConnectList update. This is achieved via new ConfigManager entity. (#777)

  Migration path (required only if you create Node manually):

  If you need to update ConnectList on file system, pass Some(path_to_node_config) as the last argument of the Node::new method. Otherwise, pass None.

• exonum::crypto types now have truncated Display/Debug representations. (#797)

  Migration path:

  Use encoding::serialize::ToHex instead of Display to produce full hexadecimal representation. You have to manually check if you need to switch or can keep using the truncated representation.

  Use encoding::serialize::FromHex instead of FromStr for reverse conversion. FromStr implementation has been removed from crypto types to avoid errors.

• Existing sodiumoxide-based cryptographic backend behind opt-out sodiumoxide-crypto feature. It also allows to use your own cryptographic library with exonum. (#756)

• New kind of CLI commands has been added: info command that can be used for getting various information from a node that has not been started yet. (#731) Currently supported sub-commands:

  • core-version - prints Exonum version as a plain string.
  • list-services - prints the list of the services the node is built with in the JSON format.

• exonum::crypto::x25519 module to convert keys from Ed25519 to X25519 format has been introduced. (#722)

• storage::Entry has been extended with take and swap methods. (#781)

• Added remote public key validation when handling incoming Connect message. (#786)

• Fixed bug with incorrect peer status for a turned-off node. (#730)

• handle_consensus does not write warning for message from previous height any more. (#729)

• new_in_family constructor has been added to the Entry index. (#790)

• Added missing external_address field to the auditor final configuration. (#805)

• BlockResponse sends transactions by Hash instead of RawMessage. If the node does not have some transactions, requests are created for the corresponding transactions. Due to these changes, the block size became significantly smaller. (#664)

• RunDev structure has been made public, so it can be extended now.

• RunDev command now generates default values for api addresses in the config.

• Dependencies versions have been updated:
  • exonum_sodiumoxide to 0.0.19.
  • exonum_rocksdb to 0.7.4.

• handle_commit method in Service trait has been renamed to after_commit. (#715)

• TimeoutAdjusterConfig has been removed along with different timeout adjusters. Current behavior is similar to the Dynamic timeout adjuster and can be modified through min_propose_timeout, max_propose_timeout and propose_timeout_threshold fields in the ConsensusConfig. (#643)

  Migration path:

  • Constant timeout adjuster can be emulated by setting equal min_propose_timeout and max_propose_timeout values.
  • For Dynamic timeout adjuster simply move min, max and threshold values into min_propose_timeout, max_propose_timeout and propose_timeout_threshold correspondingly.
  • There is no possibility to emulate MovingAverage now, so Dynamic should be used as the closest alternative.

• Network connections are now encrypted using Noise Protocol. Nodes compiled with old version will not connect to the new ones. Therefore you need to update all node instances for the network to work. (#678)

• storage::Error constructor has been made private. (#689)

• ConsensusConfig::validate_configuration method has been renamed to the warn_if_nonoptimal. (#690)

• The service has been refactored and the following public structs has been moved to separate modules: TimeSchema to exonum_time::schema, TimeProvider and MockTimeProvider to exonum_time::time_provider, ValidatorTime to exonum_time::api. (#604)

• Private API now support CORS. (#675)

• The --public-allow-origin and --private-allow-origin parameters have been added to the finalize command. (#675)

• IPv6 addressing is now supported. (#615)

• Field, CryptoHash, StorageValue and ExonumJson traits have been implemented for chrono::Duration structure. (#653)

• before_commit method has been added in Service trait. (#667) (#715)

• Field, CryptoHash, StorageKey, StorageValue and ExonumJson traits have been implemented for rust_decimal::Decimal. (#671)

• Maintenance CLI command for node management has been added. Currently the only supported command is clear-cache which clears node message cache. (#676)

• StoredConfiguration validation has been extended with txs_block_limit parameter check. (#690)

• A warning for non-optimal StoredConfiguration::txs_block_limit value has been added. (#690)

• Private api /v1/network/ endpoint now returns core version in addition to service info. (#701)

• Additional service example has been added along with frontend. (#646)

• Advanced cryptocurrency example becomes a public library (is published on crates.io). (#709)

• Already processed transactions are rejected now in NodeHandler::handle_incoming_tx method. (#642)

• Fixed bug with shutdown requests handling. (#666)

• Fixed deserialization of the MapProof data structure. (#674)

• Fixed a bug which prevented the node from reaching the actual round. (#680 #681)

• Error description has been added to the return value of the transactions. (#695)

• Error description has been added to the return value of the transactions. (#695)

• Frontend has been updated to reflect latest backend changes. (#602 #611)

• Default implementation of check method was added to Field trait to reduce boilerplate. (#639)

• Metrics are now using chrono::DateTime<Utc> instead of SystemTime. (#620)

• Method ProposeData::set_history_hash has been removed. (#604)

• POST-requests are now handled with bodyparser crate, so all the parameters must be passed in the body. (#529)

• ProofListIndex and ProofMapIndex root_hash method has been renamed to merkle_root. (#547)

• Proofs of existence / absence for ProofMapIndexs have been reworked. They now have a linear structure with two components: key-value pairs, and additional proof information allowing to restore the Merkle root of the entire index. MapProof interface has been reworked correspondingly. (#380)

  Migration path:

  • Consult documents for the updated workflow for creation and verification of MapProofs.
  • See the README in the storage::proof_map_index module for theoretical details about the new proof structure.

• with_prefix constructor of all index types has been renamed to new_in_family. Now it uses index_id instead of prefixes. Moreover, blockchain::gen_prefix method has been removed. Instead, any type that implements StorageKey trait, can serve as an index_id. (#531)

• Several Schema's methods have been renamed (#565):

  • tx_location_by_tx_hash to transactions_locations.
  • block_txs to block_transactions.

• SystemTime previously used as storage key or value turned out to show different behavior on different platforms and, hence, has been replaced with chrono::DateTime<Utc> that behaves the same in any environment. (#557)

  Migration path:

  • Replace all SystemTime fields with chrono::DateTime<Utc> ones.
  • Use DateTime::from and into() methods to convert your existing SystemTime instances into suitable type when constructing transactions or working with database.

• Blockchain method tx_from_raw() now returns Result<Box<Transaction>, MessageError> instead of Option<Box<Transaction>>. (#567)

• events module becomes private. (#568)

• CryptoHash trait is no longer implemented for Hash. (#578)

• network_id attribute has been removed from NodeInfo and RawMessage. HEADER_LENGTH remains the same, first byte of RawMessage is now reserved and always set to 0. (#579)

• exonum::explorer module has been reworked to add new functionality. (#535, #600) In particular:

  • The explorer now allows to iterate over blocks in the blockchain in the given height range, replacing old blocks_range method.
  • block_info and tx_info methods of the explorer are renamed to block and transaction respectively.
  • TransactionInfo moved from the api::public module to the explorer module.
  • BlocksRange moved from the explorer module to the api::public module.
  • TxInfo is renamed to CommittedTransaction.
  • BlockInfo fields are private now, yet accessible with getter methods.

  Migration path:

  • Rename imported types and methods as specified above
  • Use explicit type parameter in TransactionInfo and CommittedTransaction (e.g., TransactionInfo<serde_json::Value> or TransactionInfo<MyTransaction>) if you need to deserialize transaction-related data returned from the explorer HTTP API.
  • Consult explorer module docs for further possible changes in API.

• validators-count command-line parameter has been added. Now, when generating config template using generate-template command, you must specify the number of validators. (#586)

• majority_count parameter has been added to the StoredConfiguration. See exonum-configuration changes for more details. (#546)

• Rollback mechanism in Testkit is reworked to work with checkpoints (#582):

  • old rollback by blocks in Testkit was removed;
  • checkpoint method was introduced to set checkpoints;
  • new rollback rolls back to the last set checkpoint.

  Migration path:

  • Replace every old rollback(blocks) by a pair of checkpoint() and rollback().

• Testkit api now contains two methods to work with the transaction pool (#549):

  • is_tx_in_pool - for checking transaction existence in the pool;
  • add_tx - for adding a new transaction into the pool.

  Migration path:

  • Instead of calling mempool(), one should use is_tx_in_pool or add_tx methods.

• TestKitApi::get_err method now returns ApiError, rather than a deserialized object, as it is for get. For checking such results in tests you may want to use assert_matches.

• majority_count: Option<u16> configuration parameter is introduced. Allows to increase the threshold amount of votes required to commit a new configuration proposal. By default the number of votes is calculated as 2/3 + 1 of total validators count. (#546)

• SystemTime has been replaced with chrono::DateTime<Utc>, as it provides more predictable behavior on all systems. (#557)

• ExecutionError::with_description method now takes Into<String> instead of String which allows to pass &str directly. (#592)

• New database field added to the NodeConfig. This optional setting adjusts database-specific settings, like number of simultaneously opened files. (#538)

• ExecutionError::with_description method now takes Into<String> instead of String which allows to pass &str directly. (#592)

• New database field added to the NodeConfig. This optional setting adjusts database-specific settings, like number of simultaneously opened files. (#538)

• Added v1/user_agent endpoint with information about Exonum, Rust and OS versions. (#548)

• ProofMapIndex now allows to retrieve a proof of presence / absence for an arbitrary number of elements at one time with the help of get_multiproof method. Correspondingly, MapProof allows to verify proofs for an arbitrary number of elements. (#380)

• storage::UniqueHash trait that represents a unique, but not necessary cryptographic hash function, is introduced. (#579)

• Added the opportunity to parse configuration files with missing empty structures. Fields of such structures are equal to the default values. (#576)

• CryptoHash, Field, StorageKey and StorageValue traits are implemented for the uuid::Uuid. (#588)

• Display trait is implemented for types from the crypto module. (#590)

• transactions! macro now allows empty body. (#593)

• create_block* methods of the TestKit now return the information about the created block. (#535)

• TestKit::explorer() method allows to access the blockchain explorer. (#535)

• A more complex example has been added featuring best practices for service writing. (#595)

• RawTransaction now has its own implementation of fmt::Debug trait instead of #[derive(Debug)]. The template of RawTransaction’s debug message is Transaction { version: #, service_id: #, message_type: #, length: #, hash: Hash(###) }. (#603)

• Non-committed transactions are now stored persistently in the storage instead of memory pool. (#549)

• Sandbox tests have been moved inside of the exonum core. (#568)

• The requested transactions in the TransactionsRequest are now sent by batches, rather than one by one. The number of batches depends on the size limits of the message. (#583)

• Request logging for TestKitApi now encompasses all requests. The log format is slightly changed to allow for the generic request / response form. (#601)

• exonum::crypto::CryptoHash trait is introduced, and StorageValue::hash and Message::hash methods are removed. (#442)

  Migration path:

  • For implementations of StorageValue, move the hash method to CryptoHash implementation instead.
  • For implementations of Message simply remove hash method, there's a blanket impl of CryptoHash for Message.
  • Add use exonum::crypto::CryptoHash to use the hash method.

• The StorageKey trait is re-implemented for signed integer types (i8, i16, i32 and i64) to achieve the natural ordering of produced keys. (#443)

  This change will break indices using signed integers as keys. To emulate the old implementation, you may create a wrapper around a type (e.g., struct QuirkyI32Key(i32)) and implement StorageKey for it using big endian encoding. Then, use the wrapper instead of the int type in indices. See the unit tests for StorageKey for an example.

• Transaction::execute method now returns TransactionResult that is stored in the blockchain and can be accessed through api. The changes made by transactions that return Err are discarded. To migrate, add Ok(()) as the last line to the execute method. More generally, make sure that the method returns Ok(()) on successful execution. (#385)

• Service transactions are now defined through transactions! macro that automatically assigns transaction IDs based on the declaration order. (#457)

  Migration path:

  • Move all separate transactions declared as message! into one transactions! macro.
  • Remove ID constants.
  • Replace TYPE constants with a single SERVICE_ID constant.

• Several variants were removed from ApiError enum. (#474)

  Migration path:

  • Use generic ApiError::BadRequest variant or create IronError directly.

• CommandExtension uses failure::Error instead of Box<std::error::Error> for errors. (#474)

  Migration path:

  • std::error::Error can be converted to failure::Error via .into() method.

• storage::Error implements failure::Fail instead of std::error::Error. (#474)

• CryptoHash for () now correctly calculates a hash of an empty byte array instead of returning Hash::zero(). (#483)

• Removed the 'static bound from the return value of the blockchain::Service::service_name() method. (#485)

• StorageKey trait now requires ToOwned implementation. (#392)

• Connect message has been extended with a user agent string, which breaks binary compatibility with previous versions. (#362)

• Log output become more human-readable. Now it uses rfc2822 for time formatting. This change can break scripts that analyze the log output. (#514)

• output_dir argument of the generate-testnet command has been renamed to output-dir. (#528)

• peer_addr argument of the generate-config command has been renamed to peer-address. (#528)

• Blockchain::new and Node::new now accept Into<Arc<Database>> instead of Box<Database>. (#530)

  Migration path:

  • Just pass database argument as is, for example instead of Box::new(MemoryDb::new()) use MemoryDb::new().

• Most types renamed to avoid stuttering (see here for an explanation of the term) (#496):

  • ConfigurationService to Service
  • ConfigurationServiceFactory to ServiceFactory
  • TxConfigPropose to Propose
  • TxConfigVote to Vote
  • ConfigurationSchema to Schema
  • StorageValueConfigProposeData to ProposeData
  • CONFIG_SERVICE constant to SERVICE_ID

  Check the crate documentation for more details.

  Migration path: Rename imported types from the crate, using aliases or qualified names if necessary: use exonum_configuration::Service as ConfigService.

• Multiple APIs are no longer public (#496):

  • Message identifiers
  • Mutating methods of the service schema
  • Module implementing HTTP API of the service

  Check the crate documentation for more details.

  Migration path: The restrictions are security-based and should not influence intended service use.

• ZEROVOTE is replaced with the MaybeVote type, which is now used instead of Vote in the schema method signatures. The storage format itself is unchanged (#496).

• The structure Time is removed, use SystemTime for saving validators time in ProofMapIndex instead. (#20)

• Renamed methods validators_time/validators_time_mut to validators_times/validators_times_mut in Schema. (#20)

• StorageKey and StorageValue traits are implemented for SystemTime. (#456)

• StorageValue and CryptoHash traits are implemented for bool. (#385)

• Height implements std::str::FromStr. (#474)

• v1/transactions endpoint has been extended with the transaction execution status. (#488)

• Key-indexes interface now allows to use borrowed types for the search operations. (#392)

• Added v1/shutdown endpoint for graceful node termination. (#526)

• TransactionInfo from the public api module became public. (#537)

• Modified signature of the TestKitApi::send method, which previously did not accept Box<Transaction>. (#505)

• Added possibility to init a logger in TestKitBuilder. (#524)

• Information about configurations by /v1/configs/actual, /v1/configs/following and /v1/configs/committed endpoints is extended with the hash of the corresponding proposal and votes for the proposal (#481).

• Implemented error handling based on error codes (#496).

• ExonumJsonDeserialize trait is implemented for F32 and F64. (#461)

• Added round and propose timeouts validation. (#523)

• Fixed bug with the extra creation of the genesis configuration. (#527)

• Fixed panic "can't cancel routine" during node shutdown. (#530)

• Consensus messages are stored persistently (in the database), so restart will not affect the node's behavior. (#322)

• Runtime index type checks have been implemented for every index. (#525)

• Fixed logger output. (#451)

• The order of bytes and bits in the DBKey keys of ProofMapIndex became consistent. (#419)

  The change influences how Merkle Patricia trees are built for ProofMapIndex: the bits in each byte of a DBKey are now enumerated from the least significant bit (LSB) to the most significant bit (MSB), compared to MSB-to-LSB ordering used before. Note: this change will break old storages using map proofs.

• The Database trait is simplified: it is no longer required to implement state-sharing clone method. Instead, the merge method now takes a shared reference to self. (#422)

• message! and encoding_struct! no longer require manual SIZE and offset specification. (#413)

• from_raw(raw: RawMessage) method is moved to the Message trait. To migrate, add use exonum::messages::Message. (#427)

• Changed iterators over Patch and Changes data into custom types instead of standard collection iterators. (#393)

• Fixed typo in SparceListIndexKeys and SparceListIndexValues. (#398)

• Removed default state_hash implementation in the Service trait. (#399)

• Removed info method from the Transaction. (#402)

• Replaced config param timeout_events_capacity with internal_events_capacity. (#388)

• The Transaction trait now inherits from ExonumJson. (#402)

• Renamed DBKey to ProofPath and moved a part of its functionality to the BitsRange trait. (#420)

• Added patch method to the Fork structure. (#393)
• Added a public healthcheck endpoint. (#405)
• Added serialization support of floating point types through special wrapper (F32 and F64). This feature is hidden behind float_serialize gate. Note: special values (Infinity and NaN) aren't supported. (#384)
• Added a possibility to set maximum message size (pub max_message_len field in ConsensusConfig). (#426)
• Added support for CORS. (#406)
• Added run-dev command that performs a simplified node launch for testing purposes. (#423)

• Fixed consensus on the threshold of 1/3 sleeping validators. (#388)
• Fixed a bunch of inconsistencies and mistakes in the docs. (#439)
• Fixed a bug with message header validation. (#430)

• The list of peer connections is now restored to the latest state after the process is restarted. (#378)
• Log dependency was updated to 0.4, which can cause issues with the previous versions. (#433)
• Better error reporting for configs in the .toml format. (#429)

• Allow creating auditor node from command line. (#364)
• Added a new function merge_sync. In this function a write will be flushed from the operating system buffer cache before the write is considered complete. (#368)
• Added conversion into boxed values for values which implement Service or Transaction traits. (#366)
• Added constructor for the ServiceContext which can be useful for the alternative node implementations. (#366)
• Implemented AsRef<RawMessage> for any Exonum messages that were created using the message! macro. (#372)
• Implemented additional checks for conversion from raw message. (#372)

• Changed a signature of open function in a rocksdb module. RocksDBOptions should pass by the reference. (#369)
• ValidatorState in the ServiceContext replaced by the ValidatorId. (#366)
• add_transaction in the ServiceContext replaced by the transaction_sender which implements the TransactionSend trait. (#366)
• The Node constructor now requires db and services variables instead of blockchain instance. (#366)
• The Blockchain constructor now requires services keypair and an ApiSender instance. (#366)
• mount_*_api methods in Blockchain instance now do not require ApiContext. (#366)
• Rename method last_height to height in Schema. (#379)
• last_block now returns Block instead of Option<Block>. (#379)
• Replaced rocksdb command-line parameter to more generic db-path. (#376)
• Obsolete trait HexValue replaced by the FromHex and ToHex traits. (#372)
• Changed Patch and Changes from type definitions into opaque structures. (#371)
• Help text is displayed if required argument is not specified. (#390)

• Removed round method from the ServiceContext. (#366)
• Removed redundant FromRaw trait. (#372)
• Removed redundant current_height method in Schema. (#379)

• Fixed crate_authors! macro usage, this macro can't return static string in new clap version. (#370)
• Fixed mistake in description of the height getter in the ServiceContext. (#366)
• Fixed #15 consensus on the threshold of 1/3 sleeping validators. (#388)

• New events implementation based on the tokio with the separated queues for network events and timeouts and different threads for the network and node code (#300)
• Added a new index SparseListIndex. It is a list of items stored in sequential order. Similar to ListIndex but it may contain indexes without elements (#312)
• Implement FromStr and ToString traits for public sodium types (#318)
• Add a new macro metric! for collecting statistical information (#329)
• Make type DBKey public because it is used in MapProof (#306)

• RocksDB is a default storage (#178)
• Field events_pool_capacity in MemoryPoolConfig replaced by the new EventsPoolCapacity configuration (#300)
• Changed a build method new and added a new build method with_prefix for indexes (#178)
• Changed a signature of gen_prefix function in a schema module (#178)
• NodeBuilder works with ServiceFactory as trait object instead (#357)
• Debug formatting for crypto types are improved (#353)
• Added description of deserialization error for message types (#337)
• Clarified Transaction.info() usage (#345)

• Support of LevelDB is removed (#178)

• Fix the issue causing timeouts are ignored when the event pool is full (#300)
• Fix network failure due to incorrect processing of the incoming buffer (#322)

• Add RockDB support (#273)
• Add TimeoutAdjusterConfig, Constant and Dynamic timeout adjusters (#256)
• Add stream hashing and signing: HashStream and SignStream (#254)
• Add new type definitions Height and ValidatorId (#262)
• Fields of BlockInfo and TxInfo are now public (#283)
• Public export of PROOF_MAP_KEY_SIZE constant (#270)

• MapProof variant fields are renamed: left_hash and right_hash to left_node and right_node (#286)
• RequestBlock is renamed to BlockRequest and Block is renamed to BlockResponse (#287)
• All request messages are renamed: RequestFoo to FooRequest (#287)
• Improve log formatting (#291 #294)
• Make panic message during command line arguments parsing cleaner (#257)

• Fix network discover failure due to incorrect processing of the incoming buffer (#299)
• Fix snapshot behavior for MemoryDB (#292)
• Disallow generate-testnet with 0 nodes (#258)

• Fix segfault when LevelDBSnapshot is destroyed after LevelDB (#285)
• Fix panic during BlockResponse message processing if the transaction pool is full (#264)
• Fix panic during deserialization of malformed messages (#278 #297)

The first release of Exonum.