feat: accept Uint8Arrays in place of Buffers (#61)

Author: Gozala

package.json

@@ -35,7 +35,8 @@
   },
   "dependencies": {
     "base-x": "^3.0.8",
-    "buffer": "^5.5.0"
+    "buffer": "^5.5.0",
+    "web-encoding": "^1.0.2"
   },
   "devDependencies": {
     "aegir": "^25.0.0",
@@ -62,4 +63,4 @@
     "theobat <[email protected]>",
     "Henrique Dias <[email protected]>"
   ]
-}
+}

src/base.js

@@ -1,7 +1,22 @@
+// @ts-check
 'use strict'
 const { Buffer } = require('buffer')
 
+/**
+ * @typedef {Object} Codec
+ * @property {function(Uint8Array):string} encode
+ * @property {function(string):Uint8Array} decode
+ *
+ * @typedef {function(string):Codec} CodecFactory
+ */
+
 class Base {
+  /**
+   * @param {string} name
+   * @param {string} code
+   * @param {CodecFactory} implementation
+   * @param {string} alphabet
+   */
   constructor (name, code, implementation, alphabet) {
     this.name = name
     this.code = code
@@ -10,10 +25,18 @@ class Base {
     this.engine = implementation(alphabet)
   }
 
+  /**
+   * @param {Uint8Array} buf
+   * @returns {string}
+   */
   encode (buf) {
     return this.engine.encode(buf)
   }
 
+  /**
+   * @param {string} string
+   * @returns {Uint8Array}
+   */
   decode (string) {
     for (const char of string) {
       if (this.alphabet && this.alphabet.indexOf(char) < 0) {

src/constants.js

@@ -1,18 +1,24 @@
+// @ts-check
 'use strict'
 
 const baseX = require('base-x')
-const { Buffer } = require('buffer')
 const Base = require('./base.js')
 const rfc4648 = require('./rfc4648')
+const { decodeText, encodeText } = require('./util')
 
 const identity = () => {
   return {
-    encode: (data) => Buffer.from(data).toString(),
-    decode: (string) => Buffer.from(string)
+    encode: decodeText,
+    decode: encodeText
   }
 }
 
-// name, code, implementation, alphabet
+/**
+ * @typedef {import('./base').CodecFactory} CodecFactory
+ *
+ * name, code, implementation, alphabet
+ * @type {Array<[string, string, CodecFactory, string]>}
+ */
 const constants = [
   ['identity', '\x00', identity, ''],
   ['base2', '0', rfc4648(1), '01'],

src/index.js

@@ -1,3 +1,4 @@
+// @ts-check
 /**
  * Implementation of the [multibase](https://github.com/multiformats/multibase) specification.
  *
@@ -7,31 +8,37 @@
 
 const { Buffer } = require('buffer')
 const constants = require('./constants')
+const { decodeText, asBuffer } = require('./util')
 
 /** @typedef {import("./base")} Base */
 
 /**
  * Create a new buffer with the multibase varint+code.
  *
  * @param {string|number} nameOrCode - The multibase name or code number.
- * @param {Buffer} buf - The data to be prefixed with multibase.
+ * @param {Uint8Array} buf - The data to be prefixed with multibase.
  * @returns {Buffer}
  * @throws {Error} Will throw if the encoding is not supported
  */
 function multibase (nameOrCode, buf) {
   if (!buf) {
     throw new Error('requires an encoded buffer')
   }
-  const enc = encoding(nameOrCode)
-  validEncode(enc.name, buf)
-  return Buffer.concat([enc.codeBuf, buf])
+  const { name, codeBuf } = encoding(nameOrCode)
+  validEncode(name, buf)
+
+  const buffer = Buffer.alloc(codeBuf.length + buf.length)
+  buffer.set(codeBuf, 0)
+  buffer.set(buf, codeBuf.length)
+
+  return buffer
 }
 
 /**
  * Encode data with the specified base and add the multibase prefix.
  *
  * @param {string|number} nameOrCode - The multibase name or code number.
- * @param {Buffer} buf - The data to be encoded.
+ * @param {Uint8Array} buf - The data to be encoded.
  * @returns {Buffer}
  * @throws {Error} Will throw if the encoding is not supported
  *
@@ -43,17 +50,17 @@ function encode (nameOrCode, buf) {
 }
 
 /**
- * Takes a buffer or string encoded with multibase header, decodes it and
+ * Takes a Uint8Array or string encoded with multibase header, decodes it and
  * returns the decoded buffer
  *
- * @param {Buffer|string} data
+ * @param {Uint8Array|string} data
  * @returns {Buffer}
  * @throws {Error} Will throw if the encoding is not supported
  *
  */
 function decode (data) {
-  if (Buffer.isBuffer(data)) {
-    data = data.toString()
+  if (ArrayBuffer.isView(data)) {
+    data = decodeText(data)
   }
   const prefix = data[0]
 
@@ -62,18 +69,18 @@ function decode (data) {
     data = data.toLowerCase()
   }
   const enc = encoding(data[0])
-  return Buffer.from(enc.decode(data.substring(1)))
+  return asBuffer(enc.decode(data.substring(1)))
 }
 
 /**
  * Is the given data multibase encoded?
  *
- * @param {Buffer|string} data
- * @returns {boolean}
+ * @param {Uint8Array|string} data
+ * @returns {false|string}
  */
 function isEncoded (data) {
-  if (Buffer.isBuffer(data)) {
-    data = data.toString()
+  if (data instanceof Uint8Array) {
+    data = decodeText(data)
   }
 
   // Ensure bufOrString is a string
@@ -93,19 +100,19 @@ function isEncoded (data) {
  * Validate encoded data
  *
  * @param {string} name
- * @param {Buffer} buf
- * @returns {undefined}
+ * @param {Uint8Array} buf
+ * @returns {void}
  * @throws {Error} Will throw if the encoding is not supported
  */
 function validEncode (name, buf) {
   const enc = encoding(name)
-  enc.decode(buf.toString())
+  enc.decode(decodeText(buf))
 }
 
 /**
  * Get the encoding by name or code
  *
- * @param {string} nameOrCode
+ * @param {string|number} nameOrCode
  * @returns {Base}
  * @throws {Error} Will throw if the encoding is not supported
  */
@@ -122,13 +129,13 @@ function encoding (nameOrCode) {
 /**
  * Get encoding from data
  *
- * @param {string|Buffer} data
+ * @param {string|Uint8Array} data
  * @returns {Base}
  * @throws {Error} Will throw if the encoding is not supported
  */
 function encodingFromData (data) {
-  if (Buffer.isBuffer(data)) {
-    data = data.toString()
+  if (data instanceof Uint8Array) {
+    data = decodeText(data)
   }
 
   return encoding(data[0])

src/rfc4648.js

@@ -1,5 +1,14 @@
+// @ts-check
 'use strict'
 
+/** @typedef {import('./base').CodecFactory} CodecFactory */
+
+/**
+ * @param {string} string
+ * @param {string} alphabet
+ * @param {number} bitsPerChar
+ * @returns {Uint8Array}
+ */
 const decode = (string, alphabet, bitsPerChar) => {
   // Build the character lookup table:
   const codes = {}
@@ -46,6 +55,12 @@ const decode = (string, alphabet, bitsPerChar) => {
   return out
 }
 
+/**
+ * @param {Uint8Array} data
+ * @param {string} alphabet
+ * @param {number} bitsPerChar
+ * @returns {string}
+ */
 const encode = (data, alphabet, bitsPerChar) => {
   const pad = alphabet[alphabet.length - 1] === '='
   const mask = (1 << bitsPerChar) - 1
@@ -80,11 +95,23 @@ const encode = (data, alphabet, bitsPerChar) => {
   return out
 }
 
+/**
+ * @param {number} bitsPerChar
+ * @returns {CodecFactory}
+ */
 module.exports = (bitsPerChar) => (alphabet) => {
   return {
+    /**
+     * @param {Uint8Array} input
+     * @returns {string}
+     */
     encode (input) {
       return encode(input, alphabet, bitsPerChar)
     },
+    /**
+     * @param {string} input
+     * @returns {Uint8Array}
+     */
     decode (input) {
       return decode(input, alphabet, bitsPerChar)
     }

src/util.js

@@ -0,0 +1,28 @@
+// @ts-check
+'use strict'
+
+const { Buffer } = require('buffer')
+const { TextEncoder, TextDecoder } = require('web-encoding')
+
+const textDecoder = new TextDecoder()
+/**
+ * @param {ArrayBufferView|ArrayBuffer} bytes
+ * @returns {string}
+ */
+const decodeText = (bytes) => textDecoder.decode(bytes)
+
+const textEncoder = new TextEncoder()
+/**
+ * @param {string} text
+ * @returns {Uint8Array}
+ */
+const encodeText = (text) => textEncoder.encode(text)
+
+/**
+ * @param {ArrayBufferView} bytes
+ * @returns {Buffer}
+ */
+const asBuffer = ({ buffer, byteLength, byteOffset }) =>
+  Buffer.from(buffer, byteOffset, byteLength)
+
+module.exports = { decodeText, encodeText, asBuffer }