1- const BN = require ( 'bn.js' )
2- const level = require ( 'level-mem' )
3- const rlp = require ( 'rlp' )
4- const Block = require ( 'ethereumjs-block' )
5- const Cache = require ( './cache' )
6- const {
1+ import * as rlp from 'rlp'
2+ import Cache from './cache'
3+ import {
74 headsKey ,
85 headHeaderKey ,
96 headBlockKey ,
107 hashToNumberKey ,
118 numberToHashKey ,
129 tdKey ,
1310 bodyKey ,
14- headerKey
15- } = require ( './util' )
11+ headerKey ,
12+ } from './util'
13+
14+ import BN = require( 'bn.js' )
15+
16+ const level = require ( 'level-mem' )
17+ const Block = require ( 'ethereumjs-block' )
1618
1719/**
18- * Abstraction over db to facilitate storing/fetching blockchain-related
20+ * Abstraction over a DB to facilitate storing/fetching blockchain-related
1921 * data, such as blocks and headers, indices, and the head block.
2022 */
21- module . exports = class DBManager {
22- constructor ( db , common ) {
23+ export default class DBManager {
24+ _db : any
25+
26+ _common : any
27+
28+ _cache : { [ k : string ] : Cache < Buffer > }
29+
30+ constructor ( db : any , common : any ) {
2331 this . _db = db
2432 this . _common = common
2533 this . _cache = {
@@ -33,23 +41,20 @@ module.exports = class DBManager {
3341
3442 /**
3543 * Fetches iterator heads from the db.
36- * @returns Promise
3744 */
3845 getHeads ( ) {
3946 return this . get ( headsKey , { valueEncoding : 'json' } )
4047 }
4148
4249 /**
4350 * Fetches header of the head block.
44- * @returns Promise
4551 */
4652 getHeadHeader ( ) {
4753 return this . get ( headHeaderKey )
4854 }
4955
5056 /**
5157 * Fetches head block.
52- * @returns Promise
5358 */
5459 getHeadBlock ( ) {
5560 return this . get ( headBlockKey )
@@ -58,12 +63,10 @@ module.exports = class DBManager {
5863 /**
5964 * Fetches a block (header and body), given a block tag
6065 * which can be either its hash or its number.
61- * @param {Buffer|BN|number } blockTag - Hash or number of the block
62- * @returns Promise
6366 */
64- async getBlock ( blockTag ) {
67+ async getBlock ( blockTag : Buffer | BN | number ) {
6568 // determine BlockTag type
66- if ( Number . isInteger ( blockTag ) ) {
69+ if ( typeof blockTag === 'number' && Number . isInteger ( blockTag ) ) {
6770 blockTag = new BN ( blockTag )
6871 }
6972
@@ -92,55 +95,42 @@ module.exports = class DBManager {
9295
9396 /**
9497 * Fetches body of a block given its hash and number.
95- * @param {Buffer } hash
96- * @param {BN } number
97- * @returns Promise
9898 */
99- async getBody ( hash , number ) {
99+ async getBody ( hash : Buffer , number : BN ) {
100100 const key = bodyKey ( number , hash )
101101 return rlp . decode ( await this . get ( key , { cache : 'body' } ) )
102102 }
103103
104104 /**
105105 * Fetches header of a block given its hash and number.
106- * @param {Buffer } hash
107- * @param {BN } number
108- * @returns Promise
109106 */
110- async getHeader ( hash , number ) {
107+ async getHeader ( hash : Buffer , number : BN ) {
111108 const key = headerKey ( number , hash )
112- let encodedHeader = await this . get ( key , { cache : 'header' } )
109+ const encodedHeader = await this . get ( key , { cache : 'header' } )
113110 return new Block . Header ( rlp . decode ( encodedHeader ) , { common : this . _common } )
114111 }
115112
116113 /**
117114 * Fetches total difficulty for a block given its hash and number.
118- * @param {Buffer } hash
119- * @param {BN } number
120- * @returns Promise
121115 */
122- async getTd ( hash , number ) {
116+ async getTd ( hash : Buffer , number : BN ) {
123117 const key = tdKey ( number , hash )
124118 const td = await this . get ( key , { cache : 'td' } )
125119 return new BN ( rlp . decode ( td ) )
126120 }
127121
128122 /**
129123 * Performs a block hash to block number lookup.
130- * @param {Buffer } hash
131- * @returns Promise
132124 */
133- async hashToNumber ( hash ) {
125+ async hashToNumber ( hash : Buffer ) {
134126 const key = hashToNumberKey ( hash )
135127 return new BN ( await this . get ( key , { cache : 'hashToNumber' } ) )
136128 }
137129
138130 /**
139131 * Performs a block number to block hash lookup.
140- * @param {BN } number
141- * @returns Promise
142132 */
143- async numberToHash ( number ) {
133+ async numberToHash ( number : BN ) {
144134 if ( number . ltn ( 0 ) ) {
145135 throw new level . errors . NotFoundError ( )
146136 }
@@ -153,14 +143,8 @@ module.exports = class DBManager {
153143 * Fetches a key from the db. If `opts.cache` is specified
154144 * it first tries to load from cache, and on cache miss will
155145 * try to put the fetched item on cache afterwards.
156- * @param {Buffer } key
157- * @param {Object } opts - Options and their default values are:
158- * - {string} [keyEncoding='binary']
159- * - {string} [valueEncodingr='binary']
160- * - {string} [cache=undefined] name of cache to use
161- * @returns Promise
162146 */
163- async get ( key , opts = { } ) {
147+ async get ( key : string | Buffer , opts : any = { } ) {
164148 const dbOpts = {
165149 keyEncoding : opts . keyEncoding || 'binary' ,
166150 valueEncoding : opts . valueEncoding || 'binary'
@@ -173,7 +157,7 @@ module.exports = class DBManager {
173157
174158 let value = this . _cache [ opts . cache ] . get ( key )
175159 if ( ! value ) {
176- value = await this . _db . get ( key , dbOpts )
160+ value = < Buffer > await this . _db . get ( key , dbOpts )
177161 this . _cache [ opts . cache ] . set ( key , value )
178162 }
179163
@@ -185,10 +169,8 @@ module.exports = class DBManager {
185169
186170 /**
187171 * Performs a batch operation on db.
188- * @param {Array } ops
189- * @returns Promise
190172 */
191- batch ( ops ) {
173+ batch ( ops : Array < any > ) {
192174 return this . _db . batch ( ops )
193175 }
194176}
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