ethereumjs/merkle-patricia-tree-2-API

SecureTrie

Extends Trie 扩展前缀树

You can create a secure Trie where the keys are automatically hashed using SHA3 by using require('merkle-patricia-tree/secure'). It has the same methods and constructor as Trie.

你可以通过使用require('merkle-patricia-tree/secure')创建一个keys会自动使用SHA3进行hash的安全前缀树。它有着与Trie相同的方法和构造函数

Trie

src/baseTrie.js:27-55

Use require('merkel-patricia-tree') for the base interface. In Ethereum applications stick with the Secure Trie Overlay require('merkel-patricia-tree/secure'). The API for the raw and the secure interface are about the same

使用require('merkel-patricia-tree')获取基本接口。在Ethereum应用程序坚持使用安全的Trie，即require('merkel-patricia-tree/secure')。对于原始的和安全的Trie的接口的API是相同的。

Parameters参数

db Object? An instance of levelup or a compatible API. If the db is null or left undefined, then the trie will be stored in memory via memdown levelup实例或一个兼容API。如果db为null或undefined，那么trie将通过memdown存储到内存中
root (Buffer | String)? A hex String or Buffer for the root of a previously stored trie 以前存储的trie的根，为一个十六进制字符串或buffer

Properties属性

root Buffer The current root of the trie 当前trie的根
isCheckpoint Boolean determines if you are saving to a checkpoint or directly to the db 决定是保存到检查点还是直接保存到数据库
EMPTY_TRIE_ROOT Buffer the Root for an empty trie 空trie的根

get

src/baseTrie.js:64-77

Gets a value given a key

得到给定key的value

Parameters参数

key (Buffer | String) the key to search for 搜索的key
cb Function A callback Function which is given the arguments err - for errors that may have occured and value- the found value in a Buffer or if no value was found null 有给定参数err-可能发生的错误和value-在Buffer中发现的value，如果没有则为null的回调函数

put

src/baseTrie.js:87-113

Stores a given value at the given key

在给定的key上存储给定的value

Parameters参数

key (Buffer | String)
Value (Buffer | String)
cb Function A callback Function which is given the argument err - for errors that may have occured 有给定参数err-可能发生的错误的回调函数

del

src/baseTrie.js:122-140

deletes a value given a key

删除给定key的value

Parameters

key (Buffer | String)
callback Function the callback Function 回调函数

getRaw

src/baseTrie.js:149-165

Retrieves a raw value in the underlying db

检索底层数据库中的原始value

Parameters

key Buffer
callback Function A callback Function, which is given the arguments err - for errors that may have occured and value - the found value in a Buffer or if no value was found null.有给定参数err-可能发生的错误和value-在Buffer中发现的value，如果没有则为null的回调函数

putRaw

src/baseTrie.js:205-205

Writes a value directly to the underlining db

直接将value写入底层数据库

Parameters

key (Buffer | String) The key as a Buffer or String Buffer或String类型的key
value Buffer The value to be stored 存储的value
callback Function A callback Function, which is given the argument err - for errors that may have occured 有给定参数err-可能发生的错误的回调函数

delRaw

src/baseTrie.js:214-221

Removes a raw value in the underlying db

移除在底层数据库中的原始数据

Parameters

key (Buffer | String)
callback Function A callback Function, which is given the argument err - for errors that may have occured有给定参数err-可能发生的错误的回调函数

findPath

src/baseTrie.js:256-304

Trys to find a path to the node for the given key It returns a stack of nodes to the closet node

根据给定key尝试找到node的path。其返回到最近节点node的nodes的堆栈

Parameters参数

null-null (String | Buffer) key - the search key 搜索key
null-null Function cb - the callback function. Its is given the following arguments回调函数，给定以下参数
- err - any errors encontered 遇见的错误
- node - the last node found 最后找到的节点node
- keyRemainder - the remaining key nibbles not accounted for 剩余的没有找到半个字节的key
- stack - an array of nodes that forms the path to node we are searching for 一个节点数组，它构成我们正在搜索的节点的路径

createReadStream

src/baseTrie.js:723-725

The data event is given an Object hat has two properties; the key and the value. Both should be Buffers.

data事件给了带有两个属性的对象：key和value，都为Buffer类型

Returns stream.Readable Returns a stream of the contents of the trie

返回类型是stream.Readable ，返回trie内容的流

batch

src/baseTrie.js:749-761

The given hash of operations (key additions or deletions) are executed on the DB

给定的要执行在数据库上的操作(key添加或删除)的hash

Parameters

ops Array 操作的数组
cb Function

Examples

var ops = [
   { type: 'del', key: 'father' }
 , { type: 'put', key: 'name', value: 'Yuri Irsenovich Kim' }
 , { type: 'put', key: 'dob', value: '16 February 1941' }
 , { type: 'put', key: 'spouse', value: 'Kim Young-sook' }
 , { type: 'put', key: 'occupation', value: 'Clown' }
]
trie.batch(ops)

checkRoot

src/baseTrie.js:770-775

Checks if a given root exists

检查给定的root是否存在

Parameters

root Buffer
cb Function

Merkle Proof Merkle证明

Static functions for creating/verifying a merkle proof.

创建/验证Merkle证明的静态函数

prove

src/proof.js:12-29

Returns a merkle proof for a given key

根据给定key返回merkle证明

Parameters

trie Trie
key String
cb Function A callback Function (arguments {Error} err, {Array.} proof) 回调函数fun(err,proof)

verifyProof

src/proof.js:39-100

Verifies a merkle proof for a given key

根据给定key验证merkle证明

Parameters

rootHash Buffer
key String
proof Array<TrieNode>
cb Function A callback Function (arguments {Error} err, {String} val) 回调函数fun(err,val)