48 lines
2.4 KiB
JavaScript
48 lines
2.4 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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Object.defineProperty(exports, "enableMemoryDebuggingMode", {
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enumerable: true,
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get: function() {
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return enableMemoryDebuggingMode;
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}
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});
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const _v8 = /*#__PURE__*/ _interop_require_default(require("v8"));
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const _log = require("../../build/output/log");
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const _picocolors = require("../picocolors");
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const _gcobserver = require("./gc-observer");
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const _trace = require("./trace");
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function _interop_require_default(obj) {
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return obj && obj.__esModule ? obj : {
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default: obj
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};
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}
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function enableMemoryDebuggingMode() {
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// This will generate a heap snapshot when the program is close to the
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// memory limit. It does not give any warning to the user though which
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// can be jarring. If memory is large, this may take a long time.
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if ("setHeapSnapshotNearHeapLimit" in _v8.default) {
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// @ts-expect-error - this method exists since Node 16.
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_v8.default.setHeapSnapshotNearHeapLimit(1);
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}
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// This flag will kill the process when it starts to GC thrash when it's
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// close to the memory limit rather than continuing to try to collect
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// memory ineffectively.
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_v8.default.setFlagsFromString("--detect-ineffective-gcs-near-heap-limit");
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// This allows users to generate a heap snapshot on demand just by sending
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// a signal to the process.
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process.on("SIGUSR2", ()=>{
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(0, _log.warn)(`Received SIGUSR2 signal. Generating heap snapshot. ${(0, _picocolors.italic)("Note: this will take some time.")}`);
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_v8.default.writeHeapSnapshot();
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});
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(0, _gcobserver.startObservingGc)();
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(0, _trace.startPeriodicMemoryUsageTracing)();
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(0, _log.warn)(`Memory debugging mode is enabled. ${(0, _picocolors.italic)("Note: This will affect performance.")}`);
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(0, _log.info)(" - Heap snapshots will be automatically generated when the process reaches more than 70% of the memory limit and again when the process is just about to run out of memory.");
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(0, _log.info)(` - To manually generate a heap snapshot, send the process a SIGUSR2 signal: \`kill -SIGUSR2 ${process.pid}\``);
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(0, _log.info)(" - Heap snapshots when there is high memory will take a very long time to complete and may be difficult to analyze in tools.");
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(0, _log.info)(" - See https://nextjs.org/docs/app/building-your-application/optimizing/memory-usage for more information.");
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}
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//# sourceMappingURL=startup.js.map
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