feat: cli option to not encode/decode default values

Resolves ipfs#43
D4nte · Jun 29, 2022 · ae067a8 · ae067a8
1 parent b634661
commit ae067a8
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Showing 27 changed files with 109 additions and 58 deletions.
diff --git a/packages/protons-runtime/src/codec.ts b/packages/protons-runtime/src/codec.ts
@@ -28,14 +28,16 @@ export interface Codec<T> {
   encode: EncodeFunction<T>
   decode: DecodeFunction<T>
   encodingLength: EncodingLengthFunction<T>
+  defaultValue: T
 }
 
-export function createCodec <T> (name: string, type: CODEC_TYPES, encode: EncodeFunction<T>, decode: DecodeFunction<T>, encodingLength: EncodingLengthFunction<T>): Codec<T> {
+export function createCodec <T> (name: string, type: CODEC_TYPES, encode: EncodeFunction<T>, decode: DecodeFunction<T>, encodingLength: EncodingLengthFunction<T>, defaultValue: T): Codec<T> {
   return {
     name,
     type,
     encode,
     decode,
-    encodingLength
+    encodingLength,
+    defaultValue
   }
 }
diff --git a/packages/protons-runtime/src/codecs/bool.ts b/packages/protons-runtime/src/codecs/bool.ts
@@ -13,4 +13,6 @@ const decode: DecodeFunction<boolean> = function boolDecode (buffer, offset) {
   return buffer.get(offset) > 0
 }
 
-export const bool = createCodec('bool', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: boolean = false
+
+export const bool = createCodec('bool', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/bytes.ts b/packages/protons-runtime/src/codecs/bytes.ts
@@ -24,4 +24,6 @@ const decode: DecodeFunction<Uint8Array> = function bytesDecode (buf, offset) {
   return buf.slice(offset, offset + byteLength)
 }
 
-export const bytes = createCodec('bytes', CODEC_TYPES.LENGTH_DELIMITED, encode, decode, encodingLength)
+const defaultValue: Uint8Array = new Uint8Array()
+
+export const bytes = createCodec('bytes', CODEC_TYPES.LENGTH_DELIMITED, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/double.ts b/packages/protons-runtime/src/codecs/double.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<number> = function doubleDecode (buf, offset) {
   return buf.getFloat64(offset, true)
 }
 
-export const double = createCodec('double', CODEC_TYPES.BIT64, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const double = createCodec('double', CODEC_TYPES.BIT64, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/enum.ts b/packages/protons-runtime/src/codecs/enum.ts
@@ -3,6 +3,8 @@ import { unsigned } from '../utils/varint.js'
 import { createCodec, CODEC_TYPES } from '../codec.js'
 import type { DecodeFunction, EncodeFunction, EncodingLengthFunction, Codec } from '../codec.js'
 
+const defaultValue: any = 0
+
 export function enumeration <T> (v: any): Codec<T> {
   function findValue (val: string | number): number {
     if (v[val.toString()] == null) {
@@ -43,5 +45,5 @@ export function enumeration <T> (v: any): Codec<T> {
   }
 
   // @ts-expect-error yeah yeah
-  return createCodec('enum', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+  return createCodec('enum', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
 }
diff --git a/packages/protons-runtime/src/codecs/fixed32.ts b/packages/protons-runtime/src/codecs/fixed32.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<number> = function fixed32Decode (buf, offset) {
   return buf.getInt32(offset, true)
 }
 
-export const fixed32 = createCodec('fixed32', CODEC_TYPES.BIT32, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const fixed32 = createCodec('fixed32', CODEC_TYPES.BIT32, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/fixed64.ts b/packages/protons-runtime/src/codecs/fixed64.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<bigint> = function int64Decode (buf, offset) {
   return buf.getBigInt64(offset, true)
 }
 
-export const fixed64 = createCodec('fixed64', CODEC_TYPES.BIT64, encode, decode, encodingLength)
+const defaultValue: bigint = 0n
+
+export const fixed64 = createCodec('fixed64', CODEC_TYPES.BIT64, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/float.ts b/packages/protons-runtime/src/codecs/float.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<number> = function floatDecode (buf, offset) {
   return buf.getFloat32(offset, true)
 }
 
-export const float = createCodec('float', CODEC_TYPES.BIT32, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const float = createCodec('float', CODEC_TYPES.BIT32, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/int32.ts b/packages/protons-runtime/src/codecs/int32.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<number> = function int32Decode (buf, offset) {
   return signed.decode(buf, offset)
 }
 
-export const int32 = createCodec('int32', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const int32 = createCodec('int32', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/int64.ts b/packages/protons-runtime/src/codecs/int64.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<bigint> = function int64Decode (buf, offset) {
   return signed.decode(buf, offset) | 0n
 }
 
-export const int64 = createCodec('int64', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: bigint = 0n
+
+export const int64 = createCodec('int64', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/message.ts b/packages/protons-runtime/src/codecs/message.ts
@@ -4,16 +4,20 @@ import type { DecodeFunction, EncodeFunction, EncodingLengthFunction, Codec } fr
 import { Uint8ArrayList } from 'uint8arraylist'
 import type { FieldDefs, FieldDef } from '../index.js'
 
+const defaultValue: any = {}
+
 export interface Factory<A, T> {
   new (obj: A): T
 }
 
-export function message <T> (fieldDefs: FieldDefs): Codec<T> {
+export function message <T> (fieldDefs: FieldDefs, noDefaultOnWire: boolean): Codec<T> {
   const encodingLength: EncodingLengthFunction<T> = function messageEncodingLength (val: Record<string, any>) {
     let length = 0
 
     for (const fieldDef of Object.values(fieldDefs)) {
-      length += fieldDef.codec.encodingLength(val[fieldDef.name])
+      if (!noDefaultOnWire || fieldDef.codec.defaultValue !== val[fieldDef.name]) {
+        length += fieldDef.codec.encodingLength(val[fieldDef.name])
+      }
     }
 
     return unsigned.encodingLength(length) + length
@@ -31,6 +35,10 @@ export function message <T> (fieldDefs: FieldDefs): Codec<T> {
         throw new Error(`Non optional field "${fieldDef.name}" was ${value === null ? 'null' : 'undefined'}`)
       }
 
+      if (noDefaultOnWire && value === fieldDef.codec.defaultValue) {
+        return
+      }
+
       const key = (fieldNumber << 3) | fieldDef.codec.type
       const prefix = new Uint8Array(unsigned.encodingLength(key))
       unsigned.encode(key, prefix)
@@ -116,15 +124,18 @@ export function message <T> (fieldDefs: FieldDefs): Codec<T> {
       offset += fieldLength
     }
 
-    // make sure repeated fields have an array if not set
     for (const fieldDef of Object.values(fieldDefs)) {
+      // make sure repeated fields have an array if not set
       if (fieldDef.repeats === true && fields[fieldDef.name] == null) {
         fields[fieldDef.name] = []
+      } else if (noDefaultOnWire && fields[fieldDef.name] == null) {
+        // apply default values if not set
+        fields[fieldDef.name] = fieldDef.codec.defaultValue
       }
     }
 
     return fields
   }
 
-  return createCodec('message', CODEC_TYPES.LENGTH_DELIMITED, encode, decode, encodingLength)
+  return createCodec('message', CODEC_TYPES.LENGTH_DELIMITED, encode, decode, encodingLength, defaultValue)
 }
diff --git a/packages/protons-runtime/src/codecs/sfixed32.ts b/packages/protons-runtime/src/codecs/sfixed32.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<number> = function sfixed32Decode (buf, offset) {
   return buf.getInt32(offset, true)
 }
 
-export const sfixed32 = createCodec('sfixed32', CODEC_TYPES.BIT32, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const sfixed32 = createCodec('sfixed32', CODEC_TYPES.BIT32, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/sfixed64.ts b/packages/protons-runtime/src/codecs/sfixed64.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<bigint> = function sfixed64Decode (buf, offset) {
   return buf.getBigInt64(offset, true)
 }
 
-export const sfixed64 = createCodec('sfixed64', CODEC_TYPES.BIT64, encode, decode, encodingLength)
+const defaultValue: bigint = 0n
+
+export const sfixed64 = createCodec('sfixed64', CODEC_TYPES.BIT64, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/sint32.ts b/packages/protons-runtime/src/codecs/sint32.ts
@@ -18,4 +18,6 @@ const decode: DecodeFunction<number> = function svarintDecode (buf, offset) {
   return zigzag.decode(buf, offset)
 }
 
-export const sint32 = createCodec('sint32', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const sint32 = createCodec('sint32', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/sint64.ts b/packages/protons-runtime/src/codecs/sint64.ts
@@ -17,4 +17,6 @@ const decode: DecodeFunction<bigint> = function int64Decode (buf, offset) {
   return zigzag.decode(buf, offset)
 }
 
-export const sint64 = createCodec('sint64', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: bigint = 0n
+
+export const sint64 = createCodec('sint64', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/string.ts b/packages/protons-runtime/src/codecs/string.ts
@@ -26,4 +26,6 @@ const decode: DecodeFunction<string> = function stringDecode (buf, offset) {
   return uint8ArrayToString(buf.slice(offset, offset + strLen))
 }
 
-export const string = createCodec('string', CODEC_TYPES.LENGTH_DELIMITED, encode, decode, encodingLength)
+const defaultValue: string = ''
+
+export const string = createCodec('string', CODEC_TYPES.LENGTH_DELIMITED, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/uint32.ts b/packages/protons-runtime/src/codecs/uint32.ts
@@ -22,4 +22,6 @@ const decode: DecodeFunction<number> = function uint32Decode (buf, offset) {
   // return value > 2147483647 ? value - 4294967296 : value
 }
 
-export const uint32 = createCodec('uint32', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: number = 0
+
+export const uint32 = createCodec('uint32', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons-runtime/src/codecs/uint64.ts b/packages/protons-runtime/src/codecs/uint64.ts
@@ -18,4 +18,6 @@ const decode: DecodeFunction<bigint> = function uint64Decode (buf, offset) {
   return unsigned.decode(buf, offset)
 }
 
-export const uint64 = createCodec('uint64', CODEC_TYPES.VARINT, encode, decode, encodingLength)
+const defaultValue: bigint = 0n
+
+export const uint64 = createCodec('uint64', CODEC_TYPES.VARINT, encode, decode, encodingLength, defaultValue)
diff --git a/packages/protons/bin/protons.ts b/packages/protons/bin/protons.ts
@@ -10,6 +10,7 @@ async function main () {
 
   Options
     --output, -o Path to a directory to write transpiled typescript files into
+    --no-default-on-wire Do not encode default values over the wire, decode absent fields as default values 
 
   Examples
     $ protons ./path/to/file.proto ./path/to/other/file.proto
@@ -19,6 +20,10 @@ async function main () {
       output: {
         type: 'string',
         alias: 'o'
+      },
+      defaultOnWire: {
+        type: 'boolean',
+        default: true
       }
     }
   })

diff --git a/packages/protons/src/index.ts b/packages/protons/src/index.ts
@@ -125,7 +125,7 @@ function defineFields (fields: Record<string, FieldDef>, messageDef: MessageDef,
   })
 }
 
-function compileMessage (messageDef: MessageDef, moduleDef: ModuleDef): string {
+function compileMessage (messageDef: MessageDef, moduleDef: ModuleDef, noDefaultOnWire: boolean): string {
   if (isEnumDef(messageDef)) {
     moduleDef.imports.add('enumeration')
 
@@ -158,7 +158,7 @@ export namespace ${messageDef.name} {
   if (messageDef.nested != null) {
     nested = '\n'
     nested += Object.values(messageDef.nested)
-      .map(def => compileMessage(def, moduleDef).trim())
+      .map(def => compileMessage(def, moduleDef, noDefaultOnWire).trim())
       .join('\n\n')
       .split('\n')
       .map(line => line.trim() === '' ? '' : `  ${line}`)
@@ -213,7 +213,7 @@ export interface ${messageDef.name} {
 
         return `${fieldDef.id}: { name: '${name}', codec: ${codec}${fieldDef.options?.proto3_optional === true ? ', optional: true' : ''}${fieldDef.rule === 'repeated' ? ', repeats: true' : ''} }`
     }).join(',\n      ')}
-    })
+    }, ${noDefaultOnWire ? 'true' : 'false'})
   }
 
   export const encode = (obj: ${messageDef.name}): Uint8Array => {
@@ -242,7 +242,7 @@ interface ModuleDef {
   globals: Record<string, ClassDef>
 }
 
-function defineModule (def: ClassDef): ModuleDef {
+function defineModule (def: ClassDef, noDefaultOnWire: boolean): ModuleDef {
   const moduleDef: ModuleDef = {
     imports: new Set(),
     importedTypes: new Set(),
@@ -280,14 +280,15 @@ function defineModule (def: ClassDef): ModuleDef {
   for (const className of Object.keys(defs)) {
     const classDef = defs[className]
 
-    moduleDef.compiled.push(compileMessage(classDef, moduleDef))
+    moduleDef.compiled.push(compileMessage(classDef, moduleDef, noDefaultOnWire))
   }
 
   return moduleDef
 }
 
 interface Flags {
   output?: string
+  defaultOnWire: boolean
 }
 
 export async function generate (source: string, flags: Flags) {
@@ -299,7 +300,7 @@ export async function generate (source: string, flags: Flags) {
   }
 
   const def = JSON.parse(json)
-  const moduleDef = defineModule(def)
+  const moduleDef = defineModule(def, !flags.defaultOnWire)
 
   let lines = [
     '/* eslint-disable import/export */',

diff --git a/packages/protons/test/fixtures/basic.ts b/packages/protons/test/fixtures/basic.ts
@@ -14,7 +14,7 @@ export namespace Basic {
     return message<Basic>({
       1: { name: 'foo', codec: string },
       2: { name: 'num', codec: int32 }
-    })
+    }, false)
   }
 
   export const encode = (obj: Basic): Uint8Array => {

diff --git a/packages/protons/test/fixtures/circuit.ts b/packages/protons/test/fixtures/circuit.ts
@@ -86,7 +86,7 @@ export namespace CircuitRelay {
       return message<Peer>({
         1: { name: 'id', codec: bytes },
         2: { name: 'addrs', codec: bytes, repeats: true }
-      })
+      }, false)
     }
 
     export const encode = (obj: Peer): Uint8Array => {
@@ -104,7 +104,7 @@ export namespace CircuitRelay {
       2: { name: 'srcPeer', codec: CircuitRelay.Peer.codec(), optional: true },
       3: { name: 'dstPeer', codec: CircuitRelay.Peer.codec(), optional: true },
       4: { name: 'code', codec: CircuitRelay.Status.codec(), optional: true }
-    })
+    }, false)
   }
 
   export const encode = (obj: CircuitRelay): Uint8Array => {