basic query builder, cache, and polling fns

index.js

@@ -1,5 +1,7 @@
 const ArweaveLib = require('arweave')
 const { LRUMap } = require('lru_map')
+const { backOff } = require('exponential-backoff')
+const fetch = require('cross-fetch')
 
 const DEFAULT_OPTIONS = {
  host: 'arweave.net',
@@ -14,8 +16,9 @@ class Document {
  data
  txID
  client
- synced
+ posted
 
+ // Creates a new document. Not synced by default!
  constructor(parentClient, content, version, name, meta) {
  this.client = parentClient
  this.data = {
@@ -25,16 +28,33 @@ class Document {
  meta,
  }
  this.txID = undefined
- this.synced = false
+ this.posted = false
  }
 
- update(partialDocument) {
- this.synced = false
+ // Update document with a partial version of its fields.
+ // Automatically bumps version field unless explicitly defined.
+ async update(partialDocument) {
+ this.posted = false
  this.data = {
  ...this.data,
  version: this.data.version + 1,
  ...partialDocument,
  }
+ await this.client.updateDocument(this).then(() => this.posted = true)
+ }
+
+ // Wait until block is confirmed as mined using exponential retry-backoff
+ async pollForConfirmation(maxRetries = 10) {
+ if (!(this.posted && this.txID)) {
+ return Promise.reject("Document has not been posted! Use .update() first")
+ }
+
+ return await backOff(async () => {
+ const txStatus = await this.client.transactions.getStatus(this.txID)
+ return txStatus.status !== 200 ? Promise.reject(txStatus.status) : Promise.resolve()
+ }, {
+ numOfAttempts: maxRetries
+ })
  }
 }
 
@@ -52,7 +72,7 @@ class ArweaveClient {
 
  // Construct a new client given the address of the admin account,
  // keys to the wallet, and a set of options for connecting to an Arweave network.
- // Options are identical to the ones supported by the official arweave-js library
+ // Options are identical to the ones supported by the official `arweave-js` library
  constructor(adminAddress, key, cache_size = 500, options = DEFAULT_OPTIONS) {
  this.#key = key
  this.adminAddr = adminAddress
@@ -78,7 +98,6 @@ class ArweaveClient {
 
  // success, update doc data, add to cache
  doc.txID = tx.id
- doc.synced = true
  this.cache.set(doc.data.name, doc)
 
  return {
@@ -87,21 +106,85 @@ class ArweaveClient {
  }
  }
 
- async updateDocument(content, version, meta) {
+ // Internal function to see if given document is cached.
+ // Optionally define desired version to match against.
+ isCached(documentName, desiredVersion) {
+ const inCache = this.cache.has(documentName)
+ if (!inCache) {
+ return false
+ }
+
+ const cached = this.cache.get(documentName)
+ const versionMatch = desiredVersion ? cached.version === desiredVersion : true
+ return cached.synced && versionMatch
  }
 
- async getDocumentByName(name) {
- // check if doc is in cache and entry is up to date
- if (this.cache.has(name) && this.cache.get(name).synced) {
+ // take document with changes and update
+ async updateDocument(document) {
+ // check if doc is in cache and not dirty
+ if (this.isCached(name)) {
+ return Promise.resolve()
+ }
+
+ // fetch latest
+
+ }
+
+ // Internal fn for building GraphQL queries for fetching data.
+ // Both names and versions are arrays. Use `verifiedOnly = false` to include
+ // all submitted TXs (including ones from non-admin wallet accounts)
+ #queryBuilder(names, versions, verifiedOnly = true) {
+ const tags = [{
+ name: NAME,
+ values: names,
+ }]
+
+ // versions is an optional field
+ if (versions && versions.length > 0) {
+ tags.push({
+ name: VERSION,
+ values: versions,
+ })
+ }
+
+ return {
+ query: `
+ query {
+ transactions(
+ tags: ${JSON.stringify(tags)},
+ ${verifiedOnly ? `owners: ["${this.adminAddr}"]` : ""}
+ ) {
+ edges {
+ node {
+ id
+ owner {
+ address
+ }
+ tags {
+ name
+ value
+ }
+ }
+ }
+ }
+ }
+ `
+ }
+ }
+
+ async getDocumentByName(name, version) {
+ // check if doc is in cache and entry is up to date (and correct version)
+ if (this.isCached(name, version)) {
  return this.cache.get(name)
  }
 
- // otherwise, fetch latest to cache
+ // otherwise, fetch latest to cache and overwrite
 
  // return
  return this.cache.get(name)
  }
 
- // get document by specific version and hash
-
+ async getDocumentByTxId(txId) {
+ const txStatus = await this.client.transactions.getStatus(txId);
+ }
 }

package.json

@@ -18,6 +18,8 @@
  "homepage": "https://github.com/verses-xyz/ar-wrapper#readme",
  "dependencies": {
  "arweave": "^1.10.23",
+ "cross-fetch": "^3.1.5",
+ "exponential-backoff": "^3.1.0",
  "lru_map": "^0.4.1"
  }
 }