1 |
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2 |
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3 | const MAX_STACK_DEPTH = 800
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4 | const noop = _ => _
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5 |
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6 | const defer = typeof process !== 'undefined' && process.nextTick
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7 | ? process.nextTick
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8 | : typeof Promise !== 'undefined'
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9 | ? fn => Promise.resolve().then(fn)
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10 | : typeof setTimeout !== 'undefined'
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11 | ? setTimeout
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12 | : noop
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13 |
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14 | if (defer === noop) {
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15 | throw new Error(
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16 | 'Your JavaScript runtime does not support any asynchronous primitives ' +
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17 | 'that are required by vue-server-renderer. Please use a polyfill for ' +
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18 | 'either Promise or setTimeout.'
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19 | )
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20 | }
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21 |
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22 | export function createWriteFunction (
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23 | write: (text: string, next: Function) => boolean,
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24 | onError: Function
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25 | ): Function {
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26 | let stackDepth = 0
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27 | const cachedWrite = (text, next) => {
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28 | if (text && cachedWrite.caching) {
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29 | cachedWrite.cacheBuffer[cachedWrite.cacheBuffer.length - 1] += text
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30 | }
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31 | const waitForNext = write(text, next)
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32 | if (waitForNext !== true) {
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33 | if (stackDepth >= MAX_STACK_DEPTH) {
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34 | defer(() => {
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35 | try { next() } catch (e) {
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36 | onError(e)
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37 | }
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38 | })
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39 | } else {
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40 | stackDepth++
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41 | next()
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42 | stackDepth--
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43 | }
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44 | }
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45 | }
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46 | cachedWrite.caching = false
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47 | cachedWrite.cacheBuffer = []
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48 | cachedWrite.componentBuffer = []
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49 | return cachedWrite
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50 | }
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