ethereumjs/merkle-patricia-tree-2-API - 慢行厚积

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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


         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


    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

Parameters

key

( Buffer | String ) The key as a


      Buffer


        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)