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634 lines
17 KiB
634 lines
17 KiB
/** |
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* @license React |
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* scheduler.development.js |
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* |
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* Copyright (c) Facebook, Inc. and its affiliates. |
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* |
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* This source code is licensed under the MIT license found in the |
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* LICENSE file in the root directory of this source tree. |
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*/ |
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'use strict'; |
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if (process.env.NODE_ENV !== "production") { |
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(function() { |
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'use strict'; |
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/* global __REACT_DEVTOOLS_GLOBAL_HOOK__ */ |
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if ( |
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typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ !== 'undefined' && |
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typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart === |
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'function' |
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) { |
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__REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStart(new Error()); |
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} |
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var enableSchedulerDebugging = false; |
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var enableProfiling = false; |
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var frameYieldMs = 5; |
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function push(heap, node) { |
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var index = heap.length; |
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heap.push(node); |
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siftUp(heap, node, index); |
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} |
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function peek(heap) { |
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return heap.length === 0 ? null : heap[0]; |
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} |
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function pop(heap) { |
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if (heap.length === 0) { |
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return null; |
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} |
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var first = heap[0]; |
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var last = heap.pop(); |
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if (last !== first) { |
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heap[0] = last; |
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siftDown(heap, last, 0); |
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} |
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return first; |
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} |
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function siftUp(heap, node, i) { |
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var index = i; |
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while (index > 0) { |
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var parentIndex = index - 1 >>> 1; |
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var parent = heap[parentIndex]; |
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if (compare(parent, node) > 0) { |
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// The parent is larger. Swap positions. |
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heap[parentIndex] = node; |
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heap[index] = parent; |
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index = parentIndex; |
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} else { |
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// The parent is smaller. Exit. |
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return; |
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} |
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} |
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} |
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function siftDown(heap, node, i) { |
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var index = i; |
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var length = heap.length; |
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var halfLength = length >>> 1; |
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while (index < halfLength) { |
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var leftIndex = (index + 1) * 2 - 1; |
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var left = heap[leftIndex]; |
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var rightIndex = leftIndex + 1; |
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var right = heap[rightIndex]; // If the left or right node is smaller, swap with the smaller of those. |
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if (compare(left, node) < 0) { |
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if (rightIndex < length && compare(right, left) < 0) { |
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heap[index] = right; |
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heap[rightIndex] = node; |
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index = rightIndex; |
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} else { |
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heap[index] = left; |
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heap[leftIndex] = node; |
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index = leftIndex; |
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} |
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} else if (rightIndex < length && compare(right, node) < 0) { |
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heap[index] = right; |
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heap[rightIndex] = node; |
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index = rightIndex; |
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} else { |
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// Neither child is smaller. Exit. |
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return; |
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} |
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} |
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} |
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function compare(a, b) { |
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// Compare sort index first, then task id. |
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var diff = a.sortIndex - b.sortIndex; |
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return diff !== 0 ? diff : a.id - b.id; |
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} |
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// TODO: Use symbols? |
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var ImmediatePriority = 1; |
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var UserBlockingPriority = 2; |
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var NormalPriority = 3; |
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var LowPriority = 4; |
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var IdlePriority = 5; |
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function markTaskErrored(task, ms) { |
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} |
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/* eslint-disable no-var */ |
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var hasPerformanceNow = typeof performance === 'object' && typeof performance.now === 'function'; |
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if (hasPerformanceNow) { |
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var localPerformance = performance; |
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exports.unstable_now = function () { |
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return localPerformance.now(); |
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}; |
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} else { |
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var localDate = Date; |
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var initialTime = localDate.now(); |
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exports.unstable_now = function () { |
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return localDate.now() - initialTime; |
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}; |
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} // Max 31 bit integer. The max integer size in V8 for 32-bit systems. |
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// Math.pow(2, 30) - 1 |
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// 0b111111111111111111111111111111 |
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var maxSigned31BitInt = 1073741823; // Times out immediately |
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var IMMEDIATE_PRIORITY_TIMEOUT = -1; // Eventually times out |
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var USER_BLOCKING_PRIORITY_TIMEOUT = 250; |
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var NORMAL_PRIORITY_TIMEOUT = 5000; |
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var LOW_PRIORITY_TIMEOUT = 10000; // Never times out |
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var IDLE_PRIORITY_TIMEOUT = maxSigned31BitInt; // Tasks are stored on a min heap |
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var taskQueue = []; |
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var timerQueue = []; // Incrementing id counter. Used to maintain insertion order. |
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var taskIdCounter = 1; // Pausing the scheduler is useful for debugging. |
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var currentTask = null; |
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var currentPriorityLevel = NormalPriority; // This is set while performing work, to prevent re-entrance. |
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var isPerformingWork = false; |
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var isHostCallbackScheduled = false; |
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var isHostTimeoutScheduled = false; // Capture local references to native APIs, in case a polyfill overrides them. |
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var localSetTimeout = typeof setTimeout === 'function' ? setTimeout : null; |
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var localClearTimeout = typeof clearTimeout === 'function' ? clearTimeout : null; |
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var localSetImmediate = typeof setImmediate !== 'undefined' ? setImmediate : null; // IE and Node.js + jsdom |
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var isInputPending = typeof navigator !== 'undefined' && navigator.scheduling !== undefined && navigator.scheduling.isInputPending !== undefined ? navigator.scheduling.isInputPending.bind(navigator.scheduling) : null; |
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function advanceTimers(currentTime) { |
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// Check for tasks that are no longer delayed and add them to the queue. |
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var timer = peek(timerQueue); |
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while (timer !== null) { |
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if (timer.callback === null) { |
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// Timer was cancelled. |
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pop(timerQueue); |
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} else if (timer.startTime <= currentTime) { |
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// Timer fired. Transfer to the task queue. |
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pop(timerQueue); |
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timer.sortIndex = timer.expirationTime; |
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push(taskQueue, timer); |
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} else { |
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// Remaining timers are pending. |
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return; |
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} |
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timer = peek(timerQueue); |
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} |
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} |
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function handleTimeout(currentTime) { |
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isHostTimeoutScheduled = false; |
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advanceTimers(currentTime); |
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if (!isHostCallbackScheduled) { |
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if (peek(taskQueue) !== null) { |
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isHostCallbackScheduled = true; |
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requestHostCallback(flushWork); |
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} else { |
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var firstTimer = peek(timerQueue); |
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if (firstTimer !== null) { |
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requestHostTimeout(handleTimeout, firstTimer.startTime - currentTime); |
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} |
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} |
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} |
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} |
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function flushWork(hasTimeRemaining, initialTime) { |
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isHostCallbackScheduled = false; |
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if (isHostTimeoutScheduled) { |
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// We scheduled a timeout but it's no longer needed. Cancel it. |
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isHostTimeoutScheduled = false; |
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cancelHostTimeout(); |
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} |
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isPerformingWork = true; |
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var previousPriorityLevel = currentPriorityLevel; |
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try { |
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if (enableProfiling) { |
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try { |
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return workLoop(hasTimeRemaining, initialTime); |
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} catch (error) { |
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if (currentTask !== null) { |
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var currentTime = exports.unstable_now(); |
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markTaskErrored(currentTask, currentTime); |
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currentTask.isQueued = false; |
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} |
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throw error; |
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} |
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} else { |
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// No catch in prod code path. |
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return workLoop(hasTimeRemaining, initialTime); |
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} |
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} finally { |
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currentTask = null; |
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currentPriorityLevel = previousPriorityLevel; |
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isPerformingWork = false; |
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} |
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} |
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function workLoop(hasTimeRemaining, initialTime) { |
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var currentTime = initialTime; |
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advanceTimers(currentTime); |
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currentTask = peek(taskQueue); |
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while (currentTask !== null && !(enableSchedulerDebugging )) { |
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if (currentTask.expirationTime > currentTime && (!hasTimeRemaining || shouldYieldToHost())) { |
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// This currentTask hasn't expired, and we've reached the deadline. |
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break; |
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} |
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var callback = currentTask.callback; |
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if (typeof callback === 'function') { |
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currentTask.callback = null; |
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currentPriorityLevel = currentTask.priorityLevel; |
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var didUserCallbackTimeout = currentTask.expirationTime <= currentTime; |
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var continuationCallback = callback(didUserCallbackTimeout); |
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currentTime = exports.unstable_now(); |
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if (typeof continuationCallback === 'function') { |
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currentTask.callback = continuationCallback; |
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} else { |
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if (currentTask === peek(taskQueue)) { |
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pop(taskQueue); |
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} |
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} |
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advanceTimers(currentTime); |
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} else { |
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pop(taskQueue); |
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} |
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currentTask = peek(taskQueue); |
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} // Return whether there's additional work |
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if (currentTask !== null) { |
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return true; |
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} else { |
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var firstTimer = peek(timerQueue); |
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if (firstTimer !== null) { |
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requestHostTimeout(handleTimeout, firstTimer.startTime - currentTime); |
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} |
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return false; |
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} |
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} |
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function unstable_runWithPriority(priorityLevel, eventHandler) { |
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switch (priorityLevel) { |
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case ImmediatePriority: |
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case UserBlockingPriority: |
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case NormalPriority: |
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case LowPriority: |
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case IdlePriority: |
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break; |
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default: |
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priorityLevel = NormalPriority; |
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} |
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var previousPriorityLevel = currentPriorityLevel; |
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currentPriorityLevel = priorityLevel; |
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try { |
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return eventHandler(); |
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} finally { |
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currentPriorityLevel = previousPriorityLevel; |
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} |
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} |
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function unstable_next(eventHandler) { |
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var priorityLevel; |
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switch (currentPriorityLevel) { |
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case ImmediatePriority: |
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case UserBlockingPriority: |
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case NormalPriority: |
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// Shift down to normal priority |
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priorityLevel = NormalPriority; |
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break; |
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default: |
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// Anything lower than normal priority should remain at the current level. |
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priorityLevel = currentPriorityLevel; |
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break; |
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} |
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var previousPriorityLevel = currentPriorityLevel; |
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currentPriorityLevel = priorityLevel; |
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try { |
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return eventHandler(); |
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} finally { |
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currentPriorityLevel = previousPriorityLevel; |
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} |
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} |
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function unstable_wrapCallback(callback) { |
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var parentPriorityLevel = currentPriorityLevel; |
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return function () { |
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// This is a fork of runWithPriority, inlined for performance. |
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var previousPriorityLevel = currentPriorityLevel; |
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currentPriorityLevel = parentPriorityLevel; |
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try { |
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return callback.apply(this, arguments); |
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} finally { |
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currentPriorityLevel = previousPriorityLevel; |
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} |
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}; |
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} |
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function unstable_scheduleCallback(priorityLevel, callback, options) { |
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var currentTime = exports.unstable_now(); |
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var startTime; |
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if (typeof options === 'object' && options !== null) { |
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var delay = options.delay; |
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if (typeof delay === 'number' && delay > 0) { |
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startTime = currentTime + delay; |
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} else { |
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startTime = currentTime; |
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} |
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} else { |
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startTime = currentTime; |
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} |
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var timeout; |
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switch (priorityLevel) { |
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case ImmediatePriority: |
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timeout = IMMEDIATE_PRIORITY_TIMEOUT; |
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break; |
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case UserBlockingPriority: |
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timeout = USER_BLOCKING_PRIORITY_TIMEOUT; |
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break; |
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case IdlePriority: |
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timeout = IDLE_PRIORITY_TIMEOUT; |
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break; |
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case LowPriority: |
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timeout = LOW_PRIORITY_TIMEOUT; |
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break; |
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case NormalPriority: |
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default: |
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timeout = NORMAL_PRIORITY_TIMEOUT; |
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break; |
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} |
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var expirationTime = startTime + timeout; |
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var newTask = { |
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id: taskIdCounter++, |
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callback: callback, |
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priorityLevel: priorityLevel, |
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startTime: startTime, |
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expirationTime: expirationTime, |
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sortIndex: -1 |
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}; |
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if (startTime > currentTime) { |
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// This is a delayed task. |
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newTask.sortIndex = startTime; |
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push(timerQueue, newTask); |
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if (peek(taskQueue) === null && newTask === peek(timerQueue)) { |
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// All tasks are delayed, and this is the task with the earliest delay. |
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if (isHostTimeoutScheduled) { |
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// Cancel an existing timeout. |
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cancelHostTimeout(); |
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} else { |
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isHostTimeoutScheduled = true; |
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} // Schedule a timeout. |
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requestHostTimeout(handleTimeout, startTime - currentTime); |
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} |
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} else { |
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newTask.sortIndex = expirationTime; |
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push(taskQueue, newTask); |
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// wait until the next time we yield. |
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if (!isHostCallbackScheduled && !isPerformingWork) { |
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isHostCallbackScheduled = true; |
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requestHostCallback(flushWork); |
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} |
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} |
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return newTask; |
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} |
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function unstable_pauseExecution() { |
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} |
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function unstable_continueExecution() { |
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if (!isHostCallbackScheduled && !isPerformingWork) { |
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isHostCallbackScheduled = true; |
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requestHostCallback(flushWork); |
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} |
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} |
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function unstable_getFirstCallbackNode() { |
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return peek(taskQueue); |
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} |
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function unstable_cancelCallback(task) { |
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// remove from the queue because you can't remove arbitrary nodes from an |
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// array based heap, only the first one.) |
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task.callback = null; |
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} |
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function unstable_getCurrentPriorityLevel() { |
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return currentPriorityLevel; |
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} |
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var isMessageLoopRunning = false; |
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var scheduledHostCallback = null; |
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var taskTimeoutID = -1; // Scheduler periodically yields in case there is other work on the main |
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// thread, like user events. By default, it yields multiple times per frame. |
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// It does not attempt to align with frame boundaries, since most tasks don't |
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// need to be frame aligned; for those that do, use requestAnimationFrame. |
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var frameInterval = frameYieldMs; |
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var startTime = -1; |
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function shouldYieldToHost() { |
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var timeElapsed = exports.unstable_now() - startTime; |
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if (timeElapsed < frameInterval) { |
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// The main thread has only been blocked for a really short amount of time; |
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// smaller than a single frame. Don't yield yet. |
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return false; |
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} // The main thread has been blocked for a non-negligible amount of time. We |
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return true; |
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} |
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function requestPaint() { |
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} |
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function forceFrameRate(fps) { |
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if (fps < 0 || fps > 125) { |
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// Using console['error'] to evade Babel and ESLint |
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console['error']('forceFrameRate takes a positive int between 0 and 125, ' + 'forcing frame rates higher than 125 fps is not supported'); |
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return; |
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} |
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if (fps > 0) { |
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frameInterval = Math.floor(1000 / fps); |
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} else { |
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// reset the framerate |
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frameInterval = frameYieldMs; |
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} |
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} |
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var performWorkUntilDeadline = function () { |
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if (scheduledHostCallback !== null) { |
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var currentTime = exports.unstable_now(); // Keep track of the start time so we can measure how long the main thread |
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// has been blocked. |
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startTime = currentTime; |
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var hasTimeRemaining = true; // If a scheduler task throws, exit the current browser task so the |
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// error can be observed. |
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// |
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// Intentionally not using a try-catch, since that makes some debugging |
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// techniques harder. Instead, if `scheduledHostCallback` errors, then |
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// `hasMoreWork` will remain true, and we'll continue the work loop. |
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var hasMoreWork = true; |
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try { |
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hasMoreWork = scheduledHostCallback(hasTimeRemaining, currentTime); |
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} finally { |
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if (hasMoreWork) { |
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// If there's more work, schedule the next message event at the end |
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// of the preceding one. |
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schedulePerformWorkUntilDeadline(); |
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} else { |
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isMessageLoopRunning = false; |
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scheduledHostCallback = null; |
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} |
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} |
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} else { |
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isMessageLoopRunning = false; |
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} // Yielding to the browser will give it a chance to paint, so we can |
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}; |
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var schedulePerformWorkUntilDeadline; |
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if (typeof localSetImmediate === 'function') { |
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// Node.js and old IE. |
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// There's a few reasons for why we prefer setImmediate. |
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// |
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// Unlike MessageChannel, it doesn't prevent a Node.js process from exiting. |
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// (Even though this is a DOM fork of the Scheduler, you could get here |
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// with a mix of Node.js 15+, which has a MessageChannel, and jsdom.) |
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// https://github.com/facebook/react/issues/20756 |
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// |
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// But also, it runs earlier which is the semantic we want. |
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// If other browsers ever implement it, it's better to use it. |
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// Although both of these would be inferior to native scheduling. |
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schedulePerformWorkUntilDeadline = function () { |
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localSetImmediate(performWorkUntilDeadline); |
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}; |
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} else if (typeof MessageChannel !== 'undefined') { |
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// DOM and Worker environments. |
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// We prefer MessageChannel because of the 4ms setTimeout clamping. |
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var channel = new MessageChannel(); |
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var port = channel.port2; |
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channel.port1.onmessage = performWorkUntilDeadline; |
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schedulePerformWorkUntilDeadline = function () { |
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port.postMessage(null); |
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}; |
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} else { |
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// We should only fallback here in non-browser environments. |
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schedulePerformWorkUntilDeadline = function () { |
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localSetTimeout(performWorkUntilDeadline, 0); |
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}; |
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} |
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function requestHostCallback(callback) { |
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scheduledHostCallback = callback; |
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|
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if (!isMessageLoopRunning) { |
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isMessageLoopRunning = true; |
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schedulePerformWorkUntilDeadline(); |
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} |
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} |
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function requestHostTimeout(callback, ms) { |
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taskTimeoutID = localSetTimeout(function () { |
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callback(exports.unstable_now()); |
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}, ms); |
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} |
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function cancelHostTimeout() { |
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localClearTimeout(taskTimeoutID); |
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taskTimeoutID = -1; |
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} |
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var unstable_requestPaint = requestPaint; |
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var unstable_Profiling = null; |
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|
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exports.unstable_IdlePriority = IdlePriority; |
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exports.unstable_ImmediatePriority = ImmediatePriority; |
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exports.unstable_LowPriority = LowPriority; |
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exports.unstable_NormalPriority = NormalPriority; |
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exports.unstable_Profiling = unstable_Profiling; |
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exports.unstable_UserBlockingPriority = UserBlockingPriority; |
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exports.unstable_cancelCallback = unstable_cancelCallback; |
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exports.unstable_continueExecution = unstable_continueExecution; |
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exports.unstable_forceFrameRate = forceFrameRate; |
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exports.unstable_getCurrentPriorityLevel = unstable_getCurrentPriorityLevel; |
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exports.unstable_getFirstCallbackNode = unstable_getFirstCallbackNode; |
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exports.unstable_next = unstable_next; |
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exports.unstable_pauseExecution = unstable_pauseExecution; |
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exports.unstable_requestPaint = unstable_requestPaint; |
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exports.unstable_runWithPriority = unstable_runWithPriority; |
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exports.unstable_scheduleCallback = unstable_scheduleCallback; |
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exports.unstable_shouldYield = shouldYieldToHost; |
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exports.unstable_wrapCallback = unstable_wrapCallback; |
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/* global __REACT_DEVTOOLS_GLOBAL_HOOK__ */ |
|
if ( |
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typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ !== 'undefined' && |
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typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop === |
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'function' |
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) { |
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__REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop(new Error()); |
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} |
|
|
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})(); |
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}
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