{ "source": "doc/api/v8.md", "modules": [ { "textRaw": "V8", "name": "v8", "stability": 2, "stabilityText": "Stable", "desc": "

This module exposes events and interfaces specific to the version of V8\nbuilt with Node.js. These interfaces are subject to change by upstream and are\ntherefore not covered under the stability index.

\n", "methods": [ { "textRaw": "getHeapStatistics()", "type": "method", "name": "getHeapStatistics", "meta": { "added": [ "v1.0.0" ] }, "desc": "

Returns an object with the following properties

\n
{\n  total_heap_size: 7326976,\n  total_heap_size_executable: 4194304,\n  total_physical_size: 7326976,\n  total_available_size: 1152656,\n  used_heap_size: 3476208,\n  heap_size_limit: 1535115264\n}\n
\n", "signatures": [ { "params": [] } ] }, { "textRaw": "getHeapSpaceStatistics()", "type": "method", "name": "getHeapSpaceStatistics", "desc": "

Returns statistics about the V8 heap spaces, i.e. the segments which make up\nthe V8 heap. Order of heap spaces nor availability of a heap space can be\nguaranteed as the statistics are provided via the V8 GetHeapSpaceStatistics\nfunction.

\n

Example result:

\n
[\n  {\n    "space_name": "new_space",\n    "space_size": 2063872,\n    "space_used_size": 951112,\n    "space_available_size": 80824,\n    "physical_space_size": 2063872\n  },\n  {\n    "space_name": "old_space",\n    "space_size": 3090560,\n    "space_used_size": 2493792,\n    "space_available_size": 0,\n    "physical_space_size": 3090560\n  },\n  {\n    "space_name": "code_space",\n    "space_size": 1260160,\n    "space_used_size": 644256,\n    "space_available_size": 960,\n    "physical_space_size": 1260160\n  },\n  {\n    "space_name": "map_space",\n    "space_size": 1094160,\n    "space_used_size": 201608,\n    "space_available_size": 0,\n    "physical_space_size": 1094160\n  },\n  {\n    "space_name": "large_object_space",\n    "space_size": 0,\n    "space_used_size": 0,\n    "space_available_size": 1490980608,\n    "physical_space_size": 0\n  }\n]\n
", "signatures": [ { "params": [] } ] }, { "textRaw": "setFlagsFromString(string)", "type": "method", "name": "setFlagsFromString", "meta": { "added": [ "v1.0.0" ] }, "desc": "

Set additional V8 command line flags. Use with care; changing settings\nafter the VM has started may result in unpredictable behavior, including\ncrashes and data loss. Or it may simply do nothing.

\n

The V8 options available for a version of Node.js may be determined by running\nnode --v8-options. An unofficial, community-maintained list of options\nand their effects is available here.

\n

Usage:

\n
// Print GC events to stdout for one minute.\nconst v8 = require('v8');\nv8.setFlagsFromString('--trace_gc');\nsetTimeout(function() { v8.setFlagsFromString('--notrace_gc'); }, 60e3);\n
\n", "signatures": [ { "params": [ { "name": "string" } ] } ] } ], "type": "module", "displayName": "V8" } ] }