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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 #24312

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doc: Buffer.from will return internal pool buffer
mritunjayz Nov 11, 2018
0c3566b
doc: buffer.from willreturn pooled buffer
mritunjayz Nov 11, 2018
7b7c4b4
length condition removed
mritunjayz Nov 17, 2018
d1f3b51
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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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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Suggested change
// prints: 344
// Prints: 344


// Default Buffer.poolsize is 8192
console.log(Buffer.poolSize);
// prints: 8192
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// prints: 8192
// Prints: 8192


// But you can change it
Buffer.poolSize = 5;
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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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// prints: 0
// Prints: 0

```

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