@live-change/db - npm Package Compare versions

Comparing version 0.2.3 to 0.2.4

lib/Database.js

@@ -174,4 +174,12 @@ const Table = require('./Table.js')
 
+  queryObjectGet(code) {
+    return queryGet.single(this, code)
+  }
+
+  queryObjectObservable(code) {
+    return queryObservable.single(this, code)
+  }
+
 }
 
 module.exports = Database

lib/queryGet.js

@@ -127,2 +127,10 @@ const { TableWriter, LogWriter } = require('./queryUpdate.js')
 
+async function querySingleGet(database, code) {
+  const reader = new QueryReader(database)
+  const writer = new QueryWriter(database)
+  await code(reader, writer)
+  return writer.getResults()[0] || null
+}
+
+queryGet.single = querySingleGet
 queryGet.QueryWriter = QueryWriter
@@ -129,0 +137,0 @@ queryGet.QueryReader = QueryReader

lib/queryObservable.js

@@ -268,2 +268,12 @@ const ReactiveDao = require("@live-change/dao")
   }
+  getSingleResultAndStartObservation() {
+    this.#observationMode = true
+    const value = (
+        Array.from(this.#results.entries())
+            .sort((a,b)=>a[0]>b[0]?1:(a[0]<b[0]?-1:0) )
+            .map(a => a[1])
+    )[0] || null
+    this.#observable.set(value)
+
+  }
   async synchronized(key, code) {
@@ -342,2 +352,59 @@ let promise = this.#locks.get(key)
 
+
+class QuerySingleObservable extends ReactiveDao.ObservableValue {
+  constructor(database, code) {
+    super()
+    this.database = database
+    this.code = code
+
+    this.disposed = false
+    this.ready = false
+    this.respawnId = 0
+
+    this.forward = null
+
+    this.readPromise = this.startReading()
+  }
+
+  async startReading() {
+    this.reader = new QueryReader(this.database)
+    this.writer = new QueryWriter(this, this.database)
+    await this.code(this.reader, this.writer)
+    this.reader.state = READER_OBSERVING
+    this.writer.getSingleResultAndStartObservation()
+  }
+
+  async putObject(object, oldObject) {
+    await this.readPromise
+    this.set(object, oldObject)
+  }
+
+  async deleteObject(object) {
+    await this.readPromise
+    this.set(null, object)
+  }
+
+  dispose() {
+    if(this.forward) {
+      this.forward.unobserve(this)
+      this.forward = null
+      return
+    }
+
+    if(this.reader) this.reader.dispose()
+
+    this.disposed = true
+    this.respawnId++
+  }
+
+  respawn() {
+    this.respawnId++
+    this.ready = false
+    this.disposed = false
+    this.startReading()
+  }
+}
+
+
+
 function queryObservable(database, code) {
@@ -347,2 +414,7 @@ return new QueryObservable(database, code)
 
+function querySingleObservable(database, code) {
+  return new QuerySingleObservable(database, code)
+}
+
+queryObservable.single = querySingleObservable
 queryObservable.QueryWriter = QueryWriter
@@ -349,0 +421,0 @@ queryObservable.QueryReader = QueryReader

package.json

 {
   "name": "@live-change/db",
-  "version": "0.2.3",
+  "version": "0.2.4",
   "description": "Database with observable data for live queries",
@@ -5,0 +5,0 @@ "main": "index.js",

No alert changes

Improved metrics

Total package byte prevSize

66123

increased by2.99%

Lines of code

2038

increased by3.5%

No dependency changes