@types/node
Version:
TypeScript definitions for node
461 lines (458 loc) • 22.2 kB
TypeScript
declare module "buffer" {
type ImplicitArrayBuffer<T extends WithImplicitCoercion<ArrayBufferLike>> = T extends
{ valueOf(): infer V extends ArrayBufferLike } ? V : T;
global {
interface BufferConstructor {
// see buffer.d.ts for implementation shared with all TypeScript versions
/**
* Allocates a new buffer containing the given {str}.
*
* @param str String to store in buffer.
* @param encoding encoding to use, optional. Default is 'utf8'
* @deprecated since v10.0.0 - Use `Buffer.from(string[, encoding])` instead.
*/
new(str: string, encoding?: BufferEncoding): Buffer<ArrayBuffer>;
/**
* Allocates a new buffer of {size} octets.
*
* @param size count of octets to allocate.
* @deprecated since v10.0.0 - Use `Buffer.alloc()` instead (also see `Buffer.allocUnsafe()`).
*/
new(size: number): Buffer<ArrayBuffer>;
/**
* Allocates a new buffer containing the given {array} of octets.
*
* @param array The octets to store.
* @deprecated since v10.0.0 - Use `Buffer.from(array)` instead.
*/
new(array: ArrayLike<number>): Buffer<ArrayBuffer>;
/**
* Produces a Buffer backed by the same allocated memory as
* the given {ArrayBuffer}/{SharedArrayBuffer}.
*
* @param arrayBuffer The ArrayBuffer with which to share memory.
* @deprecated since v10.0.0 - Use `Buffer.from(arrayBuffer[, byteOffset[, length]])` instead.
*/
new<TArrayBuffer extends ArrayBufferLike = ArrayBuffer>(arrayBuffer: TArrayBuffer): Buffer<TArrayBuffer>;
/**
* Allocates a new `Buffer` using an `array` of bytes in the range `0` – `255`.
* Array entries outside that range will be truncated to fit into it.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* // Creates a new Buffer containing the UTF-8 bytes of the string 'buffer'.
* const buf = Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]);
* ```
*
* If `array` is an `Array`-like object (that is, one with a `length` property of
* type `number`), it is treated as if it is an array, unless it is a `Buffer` or
* a `Uint8Array`. This means all other `TypedArray` variants get treated as an
* `Array`. To create a `Buffer` from the bytes backing a `TypedArray`, use
* `Buffer.copyBytesFrom()`.
*
* A `TypeError` will be thrown if `array` is not an `Array` or another type
* appropriate for `Buffer.from()` variants.
*
* `Buffer.from(array)` and `Buffer.from(string)` may also use the internal
* `Buffer` pool like `Buffer.allocUnsafe()` does.
* @since v5.10.0
*/
from(array: WithImplicitCoercion<ArrayLike<number>>): Buffer<ArrayBuffer>;
/**
* This creates a view of the `ArrayBuffer` without copying the underlying
* memory. For example, when passed a reference to the `.buffer` property of a
* `TypedArray` instance, the newly created `Buffer` will share the same
* allocated memory as the `TypedArray`'s underlying `ArrayBuffer`.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const arr = new Uint16Array(2);
*
* arr[0] = 5000;
* arr[1] = 4000;
*
* // Shares memory with `arr`.
* const buf = Buffer.from(arr.buffer);
*
* console.log(buf);
* // Prints: <Buffer 88 13 a0 0f>
*
* // Changing the original Uint16Array changes the Buffer also.
* arr[1] = 6000;
*
* console.log(buf);
* // Prints: <Buffer 88 13 70 17>
* ```
*
* The optional `byteOffset` and `length` arguments specify a memory range within
* the `arrayBuffer` that will be shared by the `Buffer`.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const ab = new ArrayBuffer(10);
* const buf = Buffer.from(ab, 0, 2);
*
* console.log(buf.length);
* // Prints: 2
* ```
*
* A `TypeError` will be thrown if `arrayBuffer` is not an `ArrayBuffer` or a
* `SharedArrayBuffer` or another type appropriate for `Buffer.from()`
* variants.
*
* It is important to remember that a backing `ArrayBuffer` can cover a range
* of memory that extends beyond the bounds of a `TypedArray` view. A new
* `Buffer` created using the `buffer` property of a `TypedArray` may extend
* beyond the range of the `TypedArray`:
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const arrA = Uint8Array.from([0x63, 0x64, 0x65, 0x66]); // 4 elements
* const arrB = new Uint8Array(arrA.buffer, 1, 2); // 2 elements
* console.log(arrA.buffer === arrB.buffer); // true
*
* const buf = Buffer.from(arrB.buffer);
* console.log(buf);
* // Prints: <Buffer 63 64 65 66>
* ```
* @since v5.10.0
* @param arrayBuffer An `ArrayBuffer`, `SharedArrayBuffer`, for example the
* `.buffer` property of a `TypedArray`.
* @param byteOffset Index of first byte to expose. **Default:** `0`.
* @param length Number of bytes to expose. **Default:**
* `arrayBuffer.byteLength - byteOffset`.
*/
from<TArrayBuffer extends WithImplicitCoercion<ArrayBufferLike>>(
arrayBuffer: TArrayBuffer,
byteOffset?: number,
length?: number,
): Buffer<ImplicitArrayBuffer<TArrayBuffer>>;
/**
* Creates a new `Buffer` containing `string`. The `encoding` parameter identifies
* the character encoding to be used when converting `string` into bytes.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf1 = Buffer.from('this is a tést');
* const buf2 = Buffer.from('7468697320697320612074c3a97374', 'hex');
*
* console.log(buf1.toString());
* // Prints: this is a tést
* console.log(buf2.toString());
* // Prints: this is a tést
* console.log(buf1.toString('latin1'));
* // Prints: this is a tést
* ```
*
* A `TypeError` will be thrown if `string` is not a string or another type
* appropriate for `Buffer.from()` variants.
*
* `Buffer.from(string)` may also use the internal `Buffer` pool like
* `Buffer.allocUnsafe()` does.
* @since v5.10.0
* @param string A string to encode.
* @param encoding The encoding of `string`. **Default:** `'utf8'`.
*/
from(string: WithImplicitCoercion<string>, encoding?: BufferEncoding): Buffer<ArrayBuffer>;
/**
* Creates a new Buffer using the passed {data}
* @param values to create a new Buffer
*/
of(...items: number[]): Buffer<ArrayBuffer>;
/**
* Returns a new `Buffer` which is the result of concatenating all the `Buffer` instances in the `list` together.
*
* If the list has no items, or if the `totalLength` is 0, then a new zero-length `Buffer` is returned.
*
* If `totalLength` is not provided, it is calculated from the `Buffer` instances
* in `list` by adding their lengths.
*
* If `totalLength` is provided, it is coerced to an unsigned integer. If the
* combined length of the `Buffer`s in `list` exceeds `totalLength`, the result is
* truncated to `totalLength`. If the combined length of the `Buffer`s in `list` is
* less than `totalLength`, the remaining space is filled with zeros.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* // Create a single `Buffer` from a list of three `Buffer` instances.
*
* const buf1 = Buffer.alloc(10);
* const buf2 = Buffer.alloc(14);
* const buf3 = Buffer.alloc(18);
* const totalLength = buf1.length + buf2.length + buf3.length;
*
* console.log(totalLength);
* // Prints: 42
*
* const bufA = Buffer.concat([buf1, buf2, buf3], totalLength);
*
* console.log(bufA);
* // Prints: <Buffer 00 00 00 00 ...>
* console.log(bufA.length);
* // Prints: 42
* ```
*
* `Buffer.concat()` may also use the internal `Buffer` pool like `Buffer.allocUnsafe()` does.
* @since v0.7.11
* @param list List of `Buffer` or {@link Uint8Array} instances to concatenate.
* @param totalLength Total length of the `Buffer` instances in `list` when concatenated.
*/
concat(list: readonly Uint8Array[], totalLength?: number): Buffer<ArrayBuffer>;
/**
* Copies the underlying memory of `view` into a new `Buffer`.
*
* ```js
* const u16 = new Uint16Array([0, 0xffff]);
* const buf = Buffer.copyBytesFrom(u16, 1, 1);
* u16[1] = 0;
* console.log(buf.length); // 2
* console.log(buf[0]); // 255
* console.log(buf[1]); // 255
* ```
* @since v19.8.0
* @param view The {TypedArray} to copy.
* @param [offset=0] The starting offset within `view`.
* @param [length=view.length - offset] The number of elements from `view` to copy.
*/
copyBytesFrom(view: NodeJS.TypedArray, offset?: number, length?: number): Buffer<ArrayBuffer>;
/**
* Allocates a new `Buffer` of `size` bytes. If `fill` is `undefined`, the`Buffer` will be zero-filled.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf = Buffer.alloc(5);
*
* console.log(buf);
* // Prints: <Buffer 00 00 00 00 00>
* ```
*
* If `size` is larger than {@link constants.MAX_LENGTH} or smaller than 0, `ERR_OUT_OF_RANGE` is thrown.
*
* If `fill` is specified, the allocated `Buffer` will be initialized by calling `buf.fill(fill)`.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf = Buffer.alloc(5, 'a');
*
* console.log(buf);
* // Prints: <Buffer 61 61 61 61 61>
* ```
*
* If both `fill` and `encoding` are specified, the allocated `Buffer` will be
* initialized by calling `buf.fill(fill, encoding)`.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf = Buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64');
*
* console.log(buf);
* // Prints: <Buffer 68 65 6c 6c 6f 20 77 6f 72 6c 64>
* ```
*
* Calling `Buffer.alloc()` can be measurably slower than the alternative `Buffer.allocUnsafe()` but ensures that the newly created `Buffer` instance
* contents will never contain sensitive data from previous allocations, including
* data that might not have been allocated for `Buffer`s.
*
* A `TypeError` will be thrown if `size` is not a number.
* @since v5.10.0
* @param size The desired length of the new `Buffer`.
* @param [fill=0] A value to pre-fill the new `Buffer` with.
* @param [encoding='utf8'] If `fill` is a string, this is its encoding.
*/
alloc(size: number, fill?: string | Uint8Array | number, encoding?: BufferEncoding): Buffer<ArrayBuffer>;
/**
* Allocates a new `Buffer` of `size` bytes. If `size` is larger than {@link constants.MAX_LENGTH} or smaller than 0, `ERR_OUT_OF_RANGE` is thrown.
*
* The underlying memory for `Buffer` instances created in this way is _not_
* _initialized_. The contents of the newly created `Buffer` are unknown and _may contain sensitive data_. Use `Buffer.alloc()` instead to initialize`Buffer` instances with zeroes.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf = Buffer.allocUnsafe(10);
*
* console.log(buf);
* // Prints (contents may vary): <Buffer a0 8b 28 3f 01 00 00 00 50 32>
*
* buf.fill(0);
*
* console.log(buf);
* // Prints: <Buffer 00 00 00 00 00 00 00 00 00 00>
* ```
*
* 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.poolSize >>> 1` (floor of `Buffer.poolSize` divided by two).
*
* Use of this pre-allocated internal memory pool is a key difference between
* calling `Buffer.alloc(size, fill)` vs. `Buffer.allocUnsafe(size).fill(fill)`.
* Specifically, `Buffer.alloc(size, fill)` will _never_ use the internal `Buffer`pool, while `Buffer.allocUnsafe(size).fill(fill)`_will_ use the internal`Buffer` pool if `size` is less
* than or equal to half `Buffer.poolSize`. The
* difference is subtle but can be important when an application requires the
* additional performance that `Buffer.allocUnsafe()` provides.
* @since v5.10.0
* @param size The desired length of the new `Buffer`.
*/
allocUnsafe(size: number): Buffer<ArrayBuffer>;
/**
* Allocates a new `Buffer` of `size` bytes. If `size` is larger than {@link constants.MAX_LENGTH} or smaller than 0, `ERR_OUT_OF_RANGE` is thrown. A zero-length `Buffer` is created if
* `size` is 0.
*
* The underlying memory for `Buffer` instances created in this way is _not_
* _initialized_. The contents of the newly created `Buffer` are unknown and _may contain sensitive data_. Use `buf.fill(0)` 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.
*
* 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
* to create an un-pooled `Buffer` instance using `Buffer.allocUnsafeSlow()` and
* then copying out the relevant bits.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* // Need to keep around a few small chunks of memory.
* const store = [];
*
* socket.on('readable', () => {
* let data;
* while (null !== (data = readable.read())) {
* // Allocate for retained data.
* const sb = Buffer.allocUnsafeSlow(10);
*
* // Copy the data into the new allocation.
* data.copy(sb, 0, 0, 10);
*
* store.push(sb);
* }
* });
* ```
*
* A `TypeError` will be thrown if `size` is not a number.
* @since v5.12.0
* @param size The desired length of the new `Buffer`.
*/
allocUnsafeSlow(size: number): Buffer<ArrayBuffer>;
}
interface Buffer<TArrayBuffer extends ArrayBufferLike = ArrayBufferLike> extends Uint8Array<TArrayBuffer> {
// see buffer.d.ts for implementation shared with all TypeScript versions
/**
* Returns a new `Buffer` that references the same memory as the original, but
* offset and cropped by the `start` and `end` indices.
*
* This method is not compatible with the `Uint8Array.prototype.slice()`,
* which is a superclass of `Buffer`. To copy the slice, use`Uint8Array.prototype.slice()`.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf = Buffer.from('buffer');
*
* const copiedBuf = Uint8Array.prototype.slice.call(buf);
* copiedBuf[0]++;
* console.log(copiedBuf.toString());
* // Prints: cuffer
*
* console.log(buf.toString());
* // Prints: buffer
*
* // With buf.slice(), the original buffer is modified.
* const notReallyCopiedBuf = buf.slice();
* notReallyCopiedBuf[0]++;
* console.log(notReallyCopiedBuf.toString());
* // Prints: cuffer
* console.log(buf.toString());
* // Also prints: cuffer (!)
* ```
* @since v0.3.0
* @deprecated Use `subarray` instead.
* @param [start=0] Where the new `Buffer` will start.
* @param [end=buf.length] Where the new `Buffer` will end (not inclusive).
*/
slice(start?: number, end?: number): Buffer<ArrayBuffer>;
/**
* Returns a new `Buffer` that references the same memory as the original, but
* offset and cropped by the `start` and `end` indices.
*
* Specifying `end` greater than `buf.length` will return the same result as
* that of `end` equal to `buf.length`.
*
* This method is inherited from [`TypedArray.prototype.subarray()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/subarray).
*
* Modifying the new `Buffer` slice will modify the memory in the original `Buffer`because the allocated memory of the two objects overlap.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* // Create a `Buffer` with the ASCII alphabet, take a slice, and modify one byte
* // from the original `Buffer`.
*
* const buf1 = Buffer.allocUnsafe(26);
*
* for (let i = 0; i < 26; i++) {
* // 97 is the decimal ASCII value for 'a'.
* buf1[i] = i + 97;
* }
*
* const buf2 = buf1.subarray(0, 3);
*
* console.log(buf2.toString('ascii', 0, buf2.length));
* // Prints: abc
*
* buf1[0] = 33;
*
* console.log(buf2.toString('ascii', 0, buf2.length));
* // Prints: !bc
* ```
*
* Specifying negative indexes causes the slice to be generated relative to the
* end of `buf` rather than the beginning.
*
* ```js
* import { Buffer } from 'node:buffer';
*
* const buf = Buffer.from('buffer');
*
* console.log(buf.subarray(-6, -1).toString());
* // Prints: buffe
* // (Equivalent to buf.subarray(0, 5).)
*
* console.log(buf.subarray(-6, -2).toString());
* // Prints: buff
* // (Equivalent to buf.subarray(0, 4).)
*
* console.log(buf.subarray(-5, -2).toString());
* // Prints: uff
* // (Equivalent to buf.subarray(1, 4).)
* ```
* @since v3.0.0
* @param [start=0] Where the new `Buffer` will start.
* @param [end=buf.length] Where the new `Buffer` will end (not inclusive).
*/
subarray(start?: number, end?: number): Buffer<TArrayBuffer>;
}
}
/** @deprecated Use `Buffer.allocUnsafeSlow()` instead. */
var SlowBuffer: {
/** @deprecated Use `Buffer.allocUnsafeSlow()` instead. */
new(size: number): Buffer<ArrayBuffer>;
prototype: Buffer;
};
}