go-blockchain, v1.1

The library that implements models and algorithms of blockchain.

Implementing a blockchain abstraction that works with a storage and a memory storage for it.

Change Log

• models:
  • blockchain:
    • storing:
      • storage;
      • last block;
    • operations:
      • creation:
        • loading the last block from the storage;
        • when the storage is empty:
          • creation a genesis block using a proofer;
          • storing the genesis block to the storage;
      • adding a block:
        • creation a block using a proofer;
        • storing the block to the storage;
• storages:
  • operations:
    • loading the last block;
    • storing a block;
  • kinds:
    • memory storage:
      • storing blocks in memory;
      • additional operations:
        • getting the stored blocks.

Features

• models:
  • block:
    • storing:
      • timestamp;
      • custom data;
      • hash;
      • previous hash;
    • operations:
      • creation (using a proofer);
      • getting merged data;
      • self-validation (using a proofer);
  • genesis block:
    • based on a usual block without a previous hash;
  • blockchain:
    • storing:
      • storage;
      • last block;
    • operations:
      • creation:
        • loading the last block from the storage;
        • when the storage is empty:
          • creation a genesis block using a proofer;
          • storing the genesis block to the storage;
      • adding a block:
        • creation a block using a proofer;
        • storing the block to the storage;
• proofers:
  • operations:
    • block hashing;
    • block validation;
  • kinds:
    • simple:
      • based on once hashing by the SHA-256 algorithm;
    • proof of work:
      • based on the Hashcash algorithm;
      • additional storing in a block (in a hash actually):
        • nonce;
        • target bit;
• storages:
  • operations:
    • loading the last block;
    • storing a block;
  • kinds:
    • memory storage:
      • storing blocks in memory;
      • additional operations:
        • getting the stored blocks.

Examples

blockchain.Blockchain:

package main

import (
    "encoding/json"
    "fmt"
    "log"
    "time"

    "github.com/thewizardplusplus/go-blockchain"
    "github.com/thewizardplusplus/go-blockchain/proofers"
    "github.com/thewizardplusplus/go-blockchain/storages"
)

type StringHasher string

func (hasher StringHasher) Hash() string {
    return string(hasher)
}

func main() {
    timestamp := time.Date(2006, time.January, 2, 15, 4, 5, 0, time.UTC)
    blockDependencies := blockchain.BlockDependencies{
        // use the custom clock function to get the same blocks
        Clock: func() time.Time {
            timestamp = timestamp.Add(time.Hour)
            return timestamp
        },
        Proofer: proofers.ProofOfWork{TargetBit: 248},
    }

    var storage storages.MemoryStorage
    blockchain, err := blockchain.NewBlockchain(
        StringHasher("genesis block"),
        blockchain.Dependencies{
            BlockDependencies: blockDependencies,
            Storage:           &storage,
        },
    )
    if err != nil {
        log.Fatalf("unable to create the blockchain: %v", err)
    }

    for i := 0; i < 5; i++ {
        if err := blockchain.AddBlock(
            StringHasher(fmt.Sprintf("block #%d", i)),
        ); err != nil {
            log.Fatalf("unable to add the block: %v", err)
        }
    }

    blocksBytes, _ := json.MarshalIndent(storage.Blocks(), "", "  ")
    fmt.Println(string(blocksBytes))

    // Output:
    // [
    //   {
    //     "Timestamp": "2006-01-02T16:04:05Z",
    //     "Data": "genesis block",
    //     "Hash": "248:225:00e26abd9974fcdea4b32eca43c9dc5c67fffa8efd53cebffa9b049fd6c2bb36",
    //     "PrevHash": ""
    //   },
    //   {
    //     "Timestamp": "2006-01-02T17:04:05Z",
    //     "Data": "block #0",
    //     "Hash": "248:198:0058f5dae6ca3451801a276c94862c7cce085e6f9371e50d80ddbb87c1438faf",
    //     "PrevHash": "248:225:00e26abd9974fcdea4b32eca43c9dc5c67fffa8efd53cebffa9b049fd6c2bb36"
    //   },
    //   {
    //     "Timestamp": "2006-01-02T18:04:05Z",
    //     "Data": "block #1",
    //     "Hash": "248:15:002fc891ad012c4a89f7b267a2ec1767415c627ff69b88b90a93be938b026efa",
    //     "PrevHash": "248:198:0058f5dae6ca3451801a276c94862c7cce085e6f9371e50d80ddbb87c1438faf"
    //   },
    //   {
    //     "Timestamp": "2006-01-02T19:04:05Z",
    //     "Data": "block #2",
    //     "Hash": "248:136:003c7def3d467a759fad481c03cadbd62e62b2c5dbc10e4bbb6e1944c158a8be",
    //     "PrevHash": "248:15:002fc891ad012c4a89f7b267a2ec1767415c627ff69b88b90a93be938b026efa"
    //   },
    //   {
    //     "Timestamp": "2006-01-02T20:04:05Z",
    //     "Data": "block #3",
    //     "Hash": "248:65:00d5800e119abe44d89469c2161be7f9645d7237697c6d14b4a72717893582fa",
    //     "PrevHash": "248:136:003c7def3d467a759fad481c03cadbd62e62b2c5dbc10e4bbb6e1944c158a8be"
    //   },
    //   {
    //     "Timestamp": "2006-01-02T21:04:05Z",
    //     "Data": "block #4",
    //     "Hash": "248:173:00b6863763acd6ec77ca3521589d8e68c118efe855657d702783e8e6aee169a9",
    //     "PrevHash": "248:65:00d5800e119abe44d89469c2161be7f9645d7237697c6d14b4a72717893582fa"
    //   }
    // ]
}

Repository

Link: https://github.com/thewizardplusplus/go-blockchain/tree/v1.1.

Content: code.

License: MIT.