Beta 7 with some repo names changed.

Client/node_modules/multicodec/src/index.js

@@ -0,0 +1,126 @@
+/**
+ * Implementation of the multicodec specification.
+ *
+ * @module multicodec
+ * @example
+ * const multicodec = require('multicodec')
+ *
+ * const prefixedProtobuf = multicodec.addPrefix('protobuf', protobufBuffer)
+ * // prefixedProtobuf 0x50...
+ *
+ */
+'use strict'
+
+const varint = require('varint')
+const intTable = require('./int-table')
+const codecNameToCodeVarint = require('./varint-table')
+const util = require('./util')
+
+exports = module.exports
+
+/**
+ * Prefix a buffer with a multicodec-packed.
+ *
+ * @param {string|number} multicodecStrOrCode
+ * @param {Buffer} data
+ * @returns {Buffer}
+ */
+exports.addPrefix = (multicodecStrOrCode, data) => {
+  let prefix
+
+  if (Buffer.isBuffer(multicodecStrOrCode)) {
+    prefix = util.varintBufferEncode(multicodecStrOrCode)
+  } else {
+    if (codecNameToCodeVarint[multicodecStrOrCode]) {
+      prefix = codecNameToCodeVarint[multicodecStrOrCode]
+    } else {
+      throw new Error('multicodec not recognized')
+    }
+  }
+  return Buffer.concat([prefix, data])
+}
+
+/**
+ * Decapsulate the multicodec-packed prefix from the data.
+ *
+ * @param {Buffer} data
+ * @returns {Buffer}
+ */
+exports.rmPrefix = (data) => {
+  varint.decode(data)
+  return data.slice(varint.decode.bytes)
+}
+
+/**
+ * Get the codec of the prefixed data.
+ * @param {Buffer} prefixedData
+ * @returns {string}
+ */
+exports.getCodec = (prefixedData) => {
+  const code = varint.decode(prefixedData)
+  const codecName = intTable.get(code)
+  if (codecName === undefined) {
+    throw new Error(`Code ${code} not found`)
+  }
+  return codecName
+}
+
+/**
+ * Get the name of the codec.
+ * @param {number} codec
+ * @returns {string}
+ */
+exports.getName = (codec) => {
+  return intTable.get(codec)
+}
+
+/**
+ * Get the code of the codec
+ * @param {string} name
+ * @returns {number}
+ */
+exports.getNumber = (name) => {
+  const code = codecNameToCodeVarint[name]
+  if (code === undefined) {
+    throw new Error('Codec `' + name + '` not found')
+  }
+  return util.varintBufferDecode(code)[0]
+}
+
+/**
+ * Get the code of the prefixed data.
+ * @param {Buffer} prefixedData
+ * @returns {number}
+ */
+exports.getCode = (prefixedData) => {
+  return varint.decode(prefixedData)
+}
+
+/**
+ * Get the code as varint of a codec name.
+ * @param {string} codecName
+ * @returns {Buffer}
+ */
+exports.getCodeVarint = (codecName) => {
+  const code = codecNameToCodeVarint[codecName]
+  if (code === undefined) {
+    throw new Error('Codec `' + codecName + '` not found')
+  }
+  return code
+}
+
+/**
+ * Get the varint of a code.
+ * @param {Number} code
+ * @returns {Array.<number>}
+ */
+exports.getVarint = (code) => {
+  return varint.encode(code)
+}
+
+// Make the constants top-level constants
+const constants = require('./constants')
+Object.assign(exports, constants)
+
+// Human friendly names for printing, e.g. in error messages
+exports.print = require('./print')