1 files changed, 599 insertions, 0 deletions
diff --git a/std/node/_buffer.ts b/std/node/_buffer.ts
new file mode 100644
index 000000000..8cbd117ca
--- /dev/null
+++ b/std/node/_buffer.ts
@@ -0,0 +1,599 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import * as hex from "../encoding/hex.ts";
+import * as base64 from "../encoding/base64.ts";
+import { normalizeEncoding, notImplemented } from "./_utils.ts";
+
+const notImplementedEncodings = [
+  "ascii",
+  "binary",
+  "latin1",
+  "ucs2",
+  "utf16le",
+];
+
+function checkEncoding(encoding = "utf8", strict = true): string {
+  if (typeof encoding !== "string" || (strict && encoding === "")) {
+    if (!strict) return "utf8";
+    throw new TypeError(`Unkown encoding: ${encoding}`);
+  }
+
+  const normalized = normalizeEncoding(encoding);
+
+  if (normalized === undefined) {
+    throw new TypeError(`Unkown encoding: ${encoding}`);
+  }
+
+  if (notImplementedEncodings.includes(encoding)) {
+    notImplemented(`"${encoding}" encoding`);
+  }
+
+  return normalized;
+}
+
+interface EncodingOp {
+  byteLength(string: string): number;
+}
+
+// https://github.com/nodejs/node/blob/56dbe466fdbc598baea3bfce289bf52b97b8b8f7/lib/buffer.js#L598
+const encodingOps: { [key: string]: EncodingOp } = {
+  utf8: {
+    byteLength: (string: string): number =>
+      new TextEncoder().encode(string).byteLength,
+  },
+  ucs2: {
+    byteLength: (string: string): number => string.length * 2,
+  },
+  utf16le: {
+    byteLength: (string: string): number => string.length * 2,
+  },
+  latin1: {
+    byteLength: (string: string): number => string.length,
+  },
+  ascii: {
+    byteLength: (string: string): number => string.length,
+  },
+  base64: {
+    byteLength: (string: string): number =>
+      base64ByteLength(string, string.length),
+  },
+  hex: {
+    byteLength: (string: string): number => string.length >>> 1,
+  },
+};
+
+function base64ByteLength(str: string, bytes: number): number {
+  // Handle padding
+  if (str.charCodeAt(bytes - 1) === 0x3d) bytes--;
+  if (bytes > 1 && str.charCodeAt(bytes - 1) === 0x3d) bytes--;
+
+  // Base64 ratio: 3/4
+  return (bytes * 3) >>> 2;
+}
+
+/**
+ * See also https://nodejs.org/api/buffer.html
+ */
+export class Buffer extends Uint8Array {
+  /**
+   * Allocates a new Buffer of size bytes.
+   */
+  static alloc(
+    size: number,
+    fill?: number | string | Uint8Array | Buffer,
+    encoding = "utf8",
+  ): Buffer {
+    if (typeof size !== "number") {
+      throw new TypeError(
+        `The "size" argument must be of type number. Received type ${typeof size}`,
+      );
+    }
+
+    const buf = new Buffer(size);
+    if (size === 0) return buf;
+
+    let bufFill;
+    if (typeof fill === "string") {
+      encoding = checkEncoding(encoding);
+      if (
+        typeof fill === "string" &&
+        fill.length === 1 &&
+        encoding === "utf8"
+      ) {
+        buf.fill(fill.charCodeAt(0));
+      } else bufFill = Buffer.from(fill, encoding);
+    } else if (typeof fill === "number") {
+      buf.fill(fill);
+    } else if (fill instanceof Uint8Array) {
+      if (fill.length === 0) {
+        throw new TypeError(
+          `The argument "value" is invalid. Received ${fill.constructor.name} []`,
+        );
+      }
+
+      bufFill = fill;
+    }
+
+    if (bufFill) {
+      if (bufFill.length > buf.length) {
+        bufFill = bufFill.subarray(0, buf.length);
+      }
+
+      let offset = 0;
+      while (offset < size) {
+        buf.set(bufFill, offset);
+        offset += bufFill.length;
+        if (offset + bufFill.length >= size) break;
+      }
+      if (offset !== size) {
+        buf.set(bufFill.subarray(0, size - offset), offset);
+      }
+    }
+
+    return buf;
+  }
+
+  static allocUnsafe(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,
+    encoding = "utf8",
+  ): number {
+    if (typeof string != "string") return string.byteLength;
+
+    encoding = normalizeEncoding(encoding) || "utf8";
+    return encodingOps[encoding].byteLength(string);
+  }
+
+  /**
+   * 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 = Buffer.allocUnsafe(totalLength);
+    let pos = 0;
+    for (const item of list) {
+      let buf: Buffer;
+      if (!(item instanceof Buffer)) {
+        buf = Buffer.from(item);
+      } else {
+        buf = item;
+      }
+      buf.copy(buffer, 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, encoding?: string): Buffer;
+  static from(
+    // deno-lint-ignore no-explicit-any
+    value: any,
+    offsetOrEncoding?: number | string,
+    length?: number,
+  ): Buffer {
+    const offset = typeof offsetOrEncoding === "string"
+      ? undefined
+      : offsetOrEncoding;
+    let encoding = typeof offsetOrEncoding === "string"
+      ? offsetOrEncoding
+      : undefined;
+
+    if (typeof value == "string") {
+      encoding = checkEncoding(encoding, false);
+      if (encoding === "hex") return new Buffer(hex.decodeString(value).buffer);
+      if (encoding === "base64") return new Buffer(base64.decode(value).buffer);
+      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: unknown): obj is Buffer {
+    return obj instanceof Buffer;
+  }
+
+  // deno-lint-ignore no-explicit-any
+  static isEncoding(encoding: any): boolean {
+    return (
+      typeof encoding === "string" &&
+      encoding.length !== 0 &&
+      normalizeEncoding(encoding) !== undefined
+    );
+  }
+
+  /**
+   * 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)
+      .subarray(0, Math.max(0, targetBuffer.length - targetStart));
+
+    if (sourceBuffer.length === 0) return 0;
+
+    targetBuffer.set(sourceBuffer, targetStart);
+    return sourceBuffer.length;
+  }
+
+  /*
+   * Returns true if both buf and otherBuffer have exactly the same bytes, false otherwise.
+   */
+  equals(otherBuffer: Uint8Array | Buffer): boolean {
+    if (!(otherBuffer instanceof Uint8Array)) {
+      throw new TypeError(
+        `The "otherBuffer" argument must be an instance of Buffer or Uint8Array. Received type ${typeof otherBuffer}`,
+      );
+    }
+
+    if (this === otherBuffer) return true;
+    if (this.byteLength !== otherBuffer.byteLength) return false;
+
+    for (let i = 0; i < this.length; i++) {
+      if (this[i] !== otherBuffer[i]) return false;
+    }
+
+    return true;
+  }
+
+  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(): Record<string, unknown> {
+    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 {
+    encoding = checkEncoding(encoding);
+
+    const b = this.subarray(start, end);
+    if (encoding === "hex") return hex.encodeToString(b);
+    if (encoding === "base64") return base64.encode(b.buffer);
+
+    return new TextDecoder(encoding).decode(b);
+  }
+
+  /**
+   * 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;
+  }
+}