Module profiler

Memory profiler module

Instructions:

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var profiler = require('profiler');

Static function

saveSnapshot

Save a heap snapshot according to the specified name

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static profiler.saveSnapshot(String fname);

Call parameters:

• fname: String, heap snapshot name

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loadSnapshot

Read a heap snapshot according to the specified name

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static HeapSnapshot profiler.loadSnapshot(String fname);

Call parameters:

• fname: String, heap snapshot name

Return result:

• HeapSnapshot, Return the read heap snapshot

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takeSnapshot

Get the heap snapshot of the current time node, the heap snapshot records the state of the JS heap at the current moment

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static HeapSnapshot profiler.takeSnapshot();

Return result:

• HeapSnapshot, Return to the obtained snapshot of heap information

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diff

Execute the given function and compare the changes of v8 heap before and after execution

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static Object profiler.diff(Function test);

Call parameters:

• test: Function, given the function to be tested

Return result:

• Object, Return the result of the comparison

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start

Start a running status sampling log

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2
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static Timer profiler.start(String fname,
    Integer time = 60000,
    Integer interval = 100);

Call parameters:

• fname: String, given log storage file name
• time: Integer, specify the sampling time, the default is 1 minute
• interval: Integer, specify the interval time, the default is 100 milliseconds

Return result:

• Timer, Return to the sampling timer, you can stop sampling in advance through the clear method

constant

Node_Hidden

Hidden nodes, which can be filtered out when displayed to the user

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const profiler.Node_Hidden = 0;

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Node_Array

Array

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const profiler.Node_Array = 1;

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Node_String

String

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const profiler.Node_String = 2;

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Node_Object

JS objects (except strings and arrays)

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const profiler.Node_Object = 3;

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Node_Code

Compiled code

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const profiler.Node_Code = 4;

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Node_Closure

Function closure

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const profiler.Node_Closure = 5;

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Node_RegExp

Regular expression

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const profiler.Node_RegExp = 6;

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Node_HeapNumber

Sorted numbers in the pile

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const profiler.Node_HeapNumber = 7;

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Node_Native

Native objects (not on the v8 heap)

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const profiler.Node_Native = 8;

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Node_Synthetic

Synthetic object

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const profiler.Node_Synthetic = 9;

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Node_ConsString

Concatenated string

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const profiler.Node_ConsString = 10;

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Node_SlicedString

Split string

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const profiler.Node_SlicedString = 11;

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Node_Symbol

Symbol (ES6)

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const profiler.Node_Symbol = 12;

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Node_SimdValue

Sorted SIMD value in the heap (ES7)

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const profiler.Node_SimdValue = 13;

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Edge_ContextVariable

Variables in the function

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const profiler.Edge_ContextVariable = 0;

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Edge_Element

Elements in the array

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const profiler.Edge_Element = 1;

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Edge_Property

Properties of the named object

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const profiler.Edge_Property = 2;

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Edge_Internal

JS inaccessible link

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const profiler.Edge_Internal = 3;

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Edge_Hidden

Point to the node where the space size needs to be calculated in advance

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const profiler.Edge_Hidden = 4;

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Edge_Shortcut

Point to a node whose space size cannot be calculated in advance

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const profiler.Edge_Shortcut = 5;

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Edge_Weak

A weak reference (ignored by GC)

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const profiler.Edge_Weak = 6;