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denoland-deno/std/node/buffer.ts

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2020-06-06 15:56:49 -04:00
/**
* See also https://nodejs.org/api/buffer.html
*/
export default class Buffer extends Uint8Array {
/**
* Allocates a new Buffer of size bytes.
*/
static alloc(size: number): Buffer {
return new Buffer(size);
}
/**
* Returns the byte length of a string when encoded. This is not the same as
* String.prototype.length, which does not account for the encoding that is
* used to convert the string into bytes.
*/
static byteLength(
string: string | Buffer | ArrayBufferView | ArrayBuffer | SharedArrayBuffer
): number {
if (typeof string != "string") return string.byteLength;
return new TextEncoder().encode(string).length;
}
/**
* Returns a new Buffer which is the result of concatenating all the Buffer
* instances in the list together.
*/
static concat(list: Buffer[] | Uint8Array[], totalLength?: number): Buffer {
if (totalLength == undefined) {
totalLength = 0;
for (const buf of list) {
totalLength += buf.length;
}
}
const buffer = new Buffer(totalLength);
let pos = 0;
for (const buf of list) {
buffer.set(buf, pos);
pos += buf.length;
}
return buffer;
}
/**
* 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.
*/
static from(array: number[]): Buffer;
/**
* 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.
*/
static from(
arrayBuffer: ArrayBuffer | SharedArrayBuffer,
byteOffset?: number,
length?: number
): Buffer;
/**
* Copies the passed buffer data onto a new Buffer instance.
*/
static from(buffer: Buffer | Uint8Array): Buffer;
/**
* Creates a new Buffer containing string.
*/
static from(string: string): Buffer;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
static from(value: any, offset?: number, length?: number): Buffer {
if (typeof value == "string")
return new Buffer(new TextEncoder().encode(value).buffer);
// workaround for https://github.com/microsoft/TypeScript/issues/38446
return new Buffer(value, offset!, length);
}
/**
* Returns true if obj is a Buffer, false otherwise.
*/
static isBuffer(obj: object): obj is Buffer {
return obj instanceof Buffer;
}
/**
* Copies data from a region of buf to a region in target, even if the target
* memory region overlaps with buf.
*/
copy(
targetBuffer: Buffer | Uint8Array,
targetStart = 0,
sourceStart = 0,
sourceEnd = this.length
): number {
const sourceBuffer = this.subarray(sourceStart, sourceEnd);
targetBuffer.set(sourceBuffer, targetStart);
return sourceBuffer.length;
}
readBigInt64BE(offset = 0): bigint {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getBigInt64(offset);
}
readBigInt64LE(offset = 0): bigint {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getBigInt64(offset, true);
}
readBigUInt64BE(offset = 0): bigint {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getBigUint64(offset);
}
readBigUInt64LE(offset = 0): bigint {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getBigUint64(offset, true);
}
readDoubleBE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getFloat64(offset);
}
readDoubleLE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getFloat64(offset, true);
}
readFloatBE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getFloat32(offset);
}
readFloatLE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getFloat32(offset, true);
}
readInt8(offset = 0): number {
return new DataView(this.buffer, this.byteOffset, this.byteLength).getInt8(
offset
);
}
readInt16BE(offset = 0): number {
return new DataView(this.buffer, this.byteOffset, this.byteLength).getInt16(
offset
);
}
readInt16LE(offset = 0): number {
return new DataView(this.buffer, this.byteOffset, this.byteLength).getInt16(
offset,
true
);
}
readInt32BE(offset = 0): number {
return new DataView(this.buffer, this.byteOffset, this.byteLength).getInt32(
offset
);
}
readInt32LE(offset = 0): number {
return new DataView(this.buffer, this.byteOffset, this.byteLength).getInt32(
offset,
true
);
}
readUInt8(offset = 0): number {
return new DataView(this.buffer, this.byteOffset, this.byteLength).getUint8(
offset
);
}
readUInt16BE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getUint16(offset);
}
readUInt16LE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getUint16(offset, true);
}
readUInt32BE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getUint32(offset);
}
readUInt32LE(offset = 0): number {
return new DataView(
this.buffer,
this.byteOffset,
this.byteLength
).getUint32(offset, true);
}
/**
* Returns a new Buffer that references the same memory as the original, but
* offset and cropped by the start and end indices.
*/
slice(begin = 0, end = this.length): Buffer {
// workaround for https://github.com/microsoft/TypeScript/issues/38665
return this.subarray(begin, end) as Buffer;
}
/**
* Returns a JSON representation of buf. JSON.stringify() implicitly calls
* this function when stringifying a Buffer instance.
*/
toJSON(): object {
return { type: "Buffer", data: Array.from(this) };
}
/**
* Decodes buf to a string according to the specified character encoding in
* encoding. start and end may be passed to decode only a subset of buf.
*/
toString(encoding = "utf8", start = 0, end = this.length): string {
return new TextDecoder(encoding).decode(this.subarray(start, end));
}
/**
* Writes string to buf at offset according to the character encoding in
* encoding. The length parameter is the number of bytes to write. If buf did
* not contain enough space to fit the entire string, only part of string will
* be written. However, partially encoded characters will not be written.
*/
write(string: string, offset = 0, length = this.length): number {
return new TextEncoder().encodeInto(
string,
this.subarray(offset, offset + length)
).written;
}
writeBigInt64BE(value: bigint, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setBigInt64(
offset,
value
);
return offset + 4;
}
writeBigInt64LE(value: bigint, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setBigInt64(
offset,
value,
true
);
return offset + 4;
}
writeBigUInt64BE(value: bigint, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setBigUint64(
offset,
value
);
return offset + 4;
}
writeBigUInt64LE(value: bigint, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setBigUint64(
offset,
value,
true
);
return offset + 4;
}
writeDoubleBE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setFloat64(
offset,
value
);
return offset + 8;
}
writeDoubleLE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setFloat64(
offset,
value,
true
);
return offset + 8;
}
writeFloatBE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setFloat32(
offset,
value
);
return offset + 4;
}
writeFloatLE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setFloat32(
offset,
value,
true
);
return offset + 4;
}
writeInt8(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setInt8(
offset,
value
);
return offset + 1;
}
writeInt16BE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setInt16(
offset,
value
);
return offset + 2;
}
writeInt16LE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setInt16(
offset,
value,
true
);
return offset + 2;
}
writeInt32BE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setUint32(
offset,
value
);
return offset + 4;
}
writeInt32LE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setInt32(
offset,
value,
true
);
return offset + 4;
}
writeUInt8(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setUint8(
offset,
value
);
return offset + 1;
}
writeUInt16BE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setUint16(
offset,
value
);
return offset + 2;
}
writeUInt16LE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setUint16(
offset,
value,
true
);
return offset + 2;
}
writeUInt32BE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setUint32(
offset,
value
);
return offset + 4;
}
writeUInt32LE(value: number, offset = 0): number {
new DataView(this.buffer, this.byteOffset, this.byteLength).setUint32(
offset,
value,
true
);
return offset + 4;
}
}
export { Buffer };
Object.defineProperty(globalThis, "Buffer", {
value: Buffer,
enumerable: false,
writable: true,
configurable: true,
});