671c5c9b84
(#2611) had suggested that an iterative version of SimpleHashFromByteSlice would be faster, presumably because we can envision some overhead accumulating from stack frames and function calls. Additionally, a recursive algorithm risks hitting the stack limit and causing a stack overflow should the tree be too large. Provided here is an iterative alternative, a simple test to assert correctness and a benchmark. On the performance side, there appears to be no overall difference: ``` BenchmarkSimpleHashAlternatives/recursive-4 20000 77677 ns/op BenchmarkSimpleHashAlternatives/iterative-4 20000 76802 ns/op ``` On the surface it might seem that the additional overhead is due to the different allocation patterns of the implementations. The recursive version uses a single `[][]byte` slices which it then re-slices at each level of the tree. The iterative version reproduces `[][]byte` once within the function and then rewrites sub-slices of that array at each level of the tree. Eexperimenting by modifying the code to simply calculate the hash and not store the result show little to no difference in performance. These preliminary results suggest: 1. The performance of the current implementation is pretty good 2. Go has low overhead for recursive functions 3. The performance of the SimpleHashFromByteSlice routine is dominated by the actual hashing of data Although this work is in no way exhaustive, point #3 suggests that optimizations of this routine would need to take an alternative approach to make significant improvements on the current performance. Finally, considering that the recursive implementation is easier to read, it might not be worthwhile to switch to a less intuitive implementation for so little benefit. * re-add slice re-writing * [crypto] Document SimpleHashFromByteSlicesIterative
Tendermint
Byzantine-Fault Tolerant State Machines. Or Blockchain, for short.
| Branch | Tests | Coverage |
|---|---|---|
| master |  |
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| develop |  |
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Tendermint Core is Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine - written in any programming language - and securely replicates it on many machines.
For protocol details, see the specification.
For detailed analysis of the consensus protocol, including safety and liveness proofs, see our recent paper, "The latest gossip on BFT consensus".
A Note on Production Readiness
While Tendermint is being used in production in private, permissioned environments, we are still working actively to harden and audit it in preparation for use in public blockchains, such as the Cosmos Network. We are also still making breaking changes to the protocol and the APIs. Thus, we tag the releases as alpha software.
In any case, if you intend to run Tendermint in production, please contact us and join the chat.
Security
To report a security vulnerability, see our bug bounty program
For examples of the kinds of bugs we're looking for, see SECURITY.md
Minimum requirements
| Requirement | Notes |
|---|---|
| Go version | Go1.11.4 or higher |
Documentation
Complete documentation can be found on the website.
Install
See the install instructions
Quick Start
- Single node
- Local cluster using docker-compose
- Remote cluster using terraform and ansible
- Join the Cosmos testnet
Contributing
Please abide by the Code of Conduct in all interactions, and the contributing guidelines when submitting code.
Join the larger community on the forum and the chat.
To learn more about the structure of the software, watch the Developer Sessions and read some Architectural Decision Records.
Learn more by reading the code and comparing it to the specification.
Versioning
Semantic Versioning
Tendermint uses Semantic Versioning to determine when and how the version changes. According to SemVer, anything in the public API can change at any time before version 1.0.0
To provide some stability to Tendermint users in these 0.X.X days, the MINOR version is used to signal breaking changes across a subset of the total public API. This subset includes all interfaces exposed to other processes (cli, rpc, p2p, etc.), but does not include the in-process Go APIs.
That said, breaking changes in the following packages will be documented in the CHANGELOG even if they don't lead to MINOR version bumps:
- crypto
- types
- rpc/client
- config
- node
- libs
- bech32
- common
- db
- errors
- log
Exported objects in these packages that are not covered by the versioning scheme
are explicitly marked by // UNSTABLE in their go doc comment and may change at any
time without notice. Functions, types, and values in any other package may also change at any time.
Upgrades
In an effort to avoid accumulating technical debt prior to 1.0.0, we do not guarantee that breaking changes (ie. bumps in the MINOR version) will work with existing tendermint blockchains. In these cases you will have to start a new blockchain, or write something custom to get the old data into the new chain.
However, any bump in the PATCH version should be compatible with existing histories (if not please open an issue).
For more information on upgrading, see UPGRADING.md
Resources
Tendermint Core
For details about the blockchain data structures and the p2p protocols, see the Tendermint specification.
For details on using the software, see the documentation which is also hosted at: https://tendermint.com/docs/
Tools
Benchmarking and monitoring is provided by tm-bench and tm-monitor, respectively.
Their code is found here and these binaries need to be built seperately.
Additional documentation is found here.
Sub-projects
Applications
- Cosmos SDK; a cryptocurrency application framework
- Ethermint; Ethereum on Tendermint
- Many more