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doc: buffer.from will return internal pool buffer #24312

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doc: Buffer.from will return internal pool buffer
mritunjayz Nov 11, 2018
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doc: buffer.from willreturn pooled buffer
mritunjayz Nov 11, 2018
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length condition removed
mritunjayz Nov 17, 2018
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buffer.from() tiny doc nit change
mritunjayz Nov 24, 2018
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23 changes: 23 additions & 0 deletions doc/api/buffer.md
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Expand Up @@ -788,6 +788,29 @@ const buf = Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]);

A `TypeError` will be thrown if `array` is not an `Array`.

`Buffer.from(array)` will also use the internal `Buffer` pool if `array.length`
is less than or equal to half [`Buffer.poolSize`] just like
[`Buffer.allocUnsafe()`] does.
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```js
const nodeBuffers = new Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
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console.log(nodeBuffers.offset);
// prints: 344
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@ChALkeR ChALkeR Mar 2, 2019

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This is not always correct. It may return 0, and any subsequent call will probably increase it.
So it doesn't always print 344.

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@vsemozhetbyt vsemozhetbyt Mar 2, 2019

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Suggested change
// prints: 344
// Prints: 344


// Default Buffer.poolsize is 8192
console.log(Buffer.poolSize);
// prints: 8192
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@vsemozhetbyt vsemozhetbyt Mar 2, 2019

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// prints: 8192
// Prints: 8192


// But you can change it
Buffer.poolSize = 5;
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@ChALkeR ChALkeR Mar 2, 2019

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This could be misleading. Changing Buffer.poolSize does have immediate effect on which buffers would be pooled, but it doesn't immediately change the size of the current pool, it changes the size of the next pool.
It does, however, take immediate effect for determining whether should the buffer be allocated from the pool or not.


const buf = new Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
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console.log(buf.offset);
// prints: 0
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@vsemozhetbyt vsemozhetbyt Mar 2, 2019

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// prints: 0
// Prints: 0

```

### Class Method: Buffer.from(arrayBuffer[, byteOffset[, length]])
<!-- YAML
added: v5.10.0
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