feat: export tables and dedup code

License: MIT
Signed-off-by: Henrique Dias <hacdias@gmail.com>

src/index.js

@@ -15,10 +15,9 @@
 /** @typedef {import('./generated-types').CodecCode} CodecCode */
 
 const varint = require('varint')
-const intTable = require('./int-table')
-const codecNameToCodeVarint = require('./varint-table')
-const util = require('./util')
 const uint8ArrayConcat = require('uint8arrays/concat')
+const util = require('./util')
+const { nameToVarint, constantToCode, nameToCode, codeToName } = require('./maps')
 
 /**
  * Prefix a buffer with a multicodec-packed.
@@ -33,8 +32,8 @@ function addPrefix (multicodecStrOrCode, data) {
   if (multicodecStrOrCode instanceof Uint8Array) {
     prefix = util.varintUint8ArrayEncode(multicodecStrOrCode)
   } else {
-    if (codecNameToCodeVarint[multicodecStrOrCode]) {
-      prefix = codecNameToCodeVarint[multicodecStrOrCode]
+    if (nameToVarint[multicodecStrOrCode]) {
+      prefix = nameToVarint[multicodecStrOrCode]
     } else {
       throw new Error('multicodec not recognized')
     }
@@ -61,7 +60,7 @@ function rmPrefix (data) {
  */
 function getCodec (prefixedData) {
   const code = varint.decode(prefixedData)
-  const codecName = intTable.get(code)
+  const codecName = codeToName[code]
   if (codecName === undefined) {
     throw new Error(`Code ${code} not found`)
   }
@@ -75,7 +74,7 @@ function getCodec (prefixedData) {
  * @returns {CodecName|undefined}
  */
 function getName (codec) {
-  return intTable.get(codec)
+  return codeToName[codec]
 }
 
 /**
@@ -85,11 +84,11 @@ function getName (codec) {
  * @returns {CodecCode}
  */
 function getNumber (name) {
-  const code = codecNameToCodeVarint[name]
+  const code = nameToCode[name]
   if (code === undefined) {
     throw new Error('Codec `' + name + '` not found')
   }
-  return varint.decode(code)
+  return code
 }
 
 /**
@@ -109,7 +108,7 @@ function getCode (prefixedData) {
  * @returns {Uint8Array}
  */
 function getCodeVarint (codecName) {
-  const code = codecNameToCodeVarint[codecName]
+  const code = nameToVarint[codecName]
   if (code === undefined) {
     throw new Error('Codec `' + codecName + '` not found')
   }
@@ -126,9 +125,6 @@ function getVarint (code) {
   return varint.encode(code)
 }
 
-// Make the constants top-level constants
-const constants = require('./constants')
-
 module.exports = {
   addPrefix,
   rmPrefix,
@@ -138,5 +134,12 @@ module.exports = {
   getCode,
   getCodeVarint,
   getVarint,
-  ...constants
+
+  // Make the constants top-level constants
+  ...constantToCode,
+
+  // Export the maps
+  nameToVarint,
+  nameToCode,
+  codeToName
 }

src/maps.js

@@ -0,0 +1,31 @@
+'use strict'
+
+/** @typedef {import('./generated-types').ConstantCodeMap} ConstantCodeMap */
+/** @typedef {import('./generated-types').NameUint8ArrayMap} NameUint8ArrayMap */
+/** @typedef {import('./generated-types').CodeNameMap} CodeNameMap */
+
+const { baseTable } = require('./generated-table')
+const varintEncode = require('./util').varintEncode
+
+const nameToVarint = /** @type {NameUint8ArrayMap} */ ({})
+const constantToCode = /** @type {ConstantCodeMap} */({})
+const codeToName = /** @type {CodeNameMap} */({})
+
+for (const name in baseTable) {
+  const code = baseTable[name]
+  nameToVarint[name] = varintEncode(code)
+
+  const constant = name.toUpperCase().replace(/-/g, '_')
+  constantToCode[constant] = code
+
+  if (!codeToName[code]) {
+    codeToName[code] = name
+  }
+}
+
+module.exports = {
+  nameToVarint: Object.freeze(nameToVarint),
+  constantToCode: Object.freeze(constantToCode),
+  nameToCode: Object.freeze(baseTable),
+  codeToName: Object.freeze(codeToName)
+}

test/multicodec.spec.js

@@ -7,7 +7,7 @@
 const { expect } = require('aegir/utils/chai')
 const multicodec = require('../src')
 const uint8ArrayFromString = require('uint8arrays/from-string')
-const { baseTable } = require('../src/base-table')
+const { nameToCode } = require('../src/maps')
 
 describe('multicodec', () => {
   it('add prefix through multicodec (string)', () => {
@@ -61,8 +61,8 @@ describe('multicodec', () => {
   })
 
   it('returns all codec numbers from names', () => {
-    for (const name in baseTable) {
-      expect(multicodec.getNumber(/** @type {CodecName} */(name))).to.eql(baseTable[name])
+    for (const name in nameToCode) {
+      expect(multicodec.getNumber(/** @type {CodecName} */(name))).to.eql(nameToCode[name])
     }
   })
 

tools/update-table.js

@@ -65,7 +65,7 @@ module.exports = { baseTable }
 `
 
   fs.writeFileSync(path.join(__dirname, '../src/generated-types.ts'), typesTemplate)
-  fs.writeFileSync(path.join(__dirname, '../src/base-table.js'), tableTemplate)
+  fs.writeFileSync(path.join(__dirname, '../src/generated-table.js'), tableTemplate)
 }
 
 run()