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doc: added Buffer.from(string) to functions that use buffer pool
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Buffer.from(string) is one of the functions that may use the
pre-allocated buffer. It's mentioned in the description of
Buffer.from(array), but not in Buffer.from(string), or in the two other
places where functions that behave this way are listed, so this commit
adds those references.
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Whitecx committed Jun 8, 2024
1 parent 83d0cfe commit 18263bd
Showing 1 changed file with 14 additions and 11 deletions.
25 changes: 14 additions & 11 deletions doc/api/buffer.md
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Expand Up @@ -808,7 +808,7 @@ A `TypeError` will be thrown if `size` is not a number.
The `Buffer` module pre-allocates an internal `Buffer` instance of
size [`Buffer.poolSize`][] that is used as a pool for the fast allocation of new
`Buffer` instances created using [`Buffer.allocUnsafe()`][], [`Buffer.from(array)`][],
and [`Buffer.concat()`][] only when `size` is less than
[`Buffer.from(string)`][], and [`Buffer.concat()`][] only when `size` is less than
`Buffer.poolSize >>> 1` (floor of [`Buffer.poolSize`][] divided by two).

Use of this pre-allocated internal memory pool is a key difference between
Expand Down Expand Up @@ -846,11 +846,11 @@ _may contain sensitive data_. Use [`buf.fill(0)`][`buf.fill()`] to initialize
such `Buffer` instances with zeroes.

When using [`Buffer.allocUnsafe()`][] to allocate new `Buffer` instances,
allocations under 4 KiB are sliced from a single pre-allocated `Buffer`. This
allows applications to avoid the garbage collection overhead of creating many
individually allocated `Buffer` instances. This approach improves both
performance and memory usage by eliminating the need to track and clean up as
many individual `ArrayBuffer` objects.
allocations less than `Buffer.poolSize >>> 1` (4KiB when default poolSize is used) are sliced
from a single pre-allocated `Buffer`. This allows applications to avoid the
garbage collection overhead of creating many individually allocated `Buffer`
instances. This approach improves both performance and memory usage by
eliminating the need to track and clean up as many individual `ArrayBuffer` objects.

However, in the case where a developer may need to retain a small chunk of
memory from a pool for an indeterminate amount of time, it may be appropriate
Expand Down Expand Up @@ -1390,7 +1390,10 @@ console.log(buf1.toString('latin1'));
A `TypeError` will be thrown if `string` is not a string or another type
appropriate for `Buffer.from()` variants.

### Static method: `Buffer.isBuffer(obj)`
[`Buffer.from(string)`][] may also use the internal `Buffer` pool like
[`Buffer.allocUnsafe()`][] does.

###. Static method: `Buffer.isBuffer(obj)`

<!-- YAML
added: v0.1.101
Expand Down Expand Up @@ -5444,10 +5447,10 @@ to one of these new APIs._
uninitialized, the allocated segment of memory might contain old data that is
potentially sensitive.

`Buffer` instances returned by [`Buffer.allocUnsafe()`][] and
[`Buffer.from(array)`][] _may_ be allocated off a shared internal memory pool
if `size` is less than or equal to half [`Buffer.poolSize`][]. Instances
returned by [`Buffer.allocUnsafeSlow()`][] _never_ use the shared internal
`Buffer` instances returned by [`Buffer.allocUnsafe()`][], [`Buffer.from(string)`][],
[`Buffer.concat()`][] and [`Buffer.from(array)`][] _may_ be allocated off a shared
internal memory pool if `size` is less than or equal to half [`Buffer.poolSize`][].
Instances returned by [`Buffer.allocUnsafeSlow()`][] _never_ use the shared internal
memory pool.

### The `--zero-fill-buffers` command-line option
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