67 lines
1.8 KiB
JavaScript
67 lines
1.8 KiB
JavaScript
import { getETag, getETagAndData } from './utils/ajax'
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import { jsonChecksum } from './utils/jsonChecksum'
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import { hasData, loadData } from './idbInterface'
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import { isSignalAborted } from './utils/isSignalAborted.js'
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export async function checkForUpdates (db, dataSource, signal) {
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// just do a simple HEAD request first to see if the eTags match
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let emojiData
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let eTag = await getETag(dataSource)
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if (isSignalAborted(signal)) {
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return
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}
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if (!eTag) { // work around lack of ETag/Access-Control-Expose-Headers
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const eTagAndData = await getETagAndData(dataSource)
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if (isSignalAborted(signal)) {
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return
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}
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eTag = eTagAndData[0]
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emojiData = eTagAndData[1]
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if (!eTag) {
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eTag = await jsonChecksum(emojiData)
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if (isSignalAborted(signal)) {
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return
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}
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}
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}
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const doesHaveData = await hasData(db, dataSource, eTag)
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if (isSignalAborted(signal)) {
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return
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}
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if (doesHaveData) {
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console.log('Database already populated')
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} else {
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console.log('Database update available')
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if (!emojiData) {
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const eTagAndData = await getETagAndData(dataSource)
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if (isSignalAborted(signal)) {
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return
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}
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emojiData = eTagAndData[1]
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}
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await loadData(db, emojiData, dataSource, eTag)
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}
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}
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export async function loadDataForFirstTime (db, dataSource, signal) {
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let [eTag, emojiData] = await getETagAndData(dataSource)
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if (isSignalAborted(signal)) {
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return
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}
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if (!eTag) {
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// Handle lack of support for ETag or Access-Control-Expose-Headers
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// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Expose-Headers#Browser_compatibility
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eTag = await jsonChecksum(emojiData)
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if (isSignalAborted(signal)) {
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return
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}
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}
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await loadData(db, emojiData, dataSource, eTag)
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}
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