BigInt writing support, and support reading from buffer offset (#113)

* support writing BigInts

* add buffer offset parameter to parsePacketBuffer

* standard fix

* lint fix, update doc

* use BigIntExtended, update to node 10

* simplify BigIntExt

* fix BigIntExt valueOf

* simplify bigint further

* valueOf -> instanceof

* remove unnecessary instanceof BigIntExt

* use typeof

* cleanup

Author: extremeheat

doc/api.md

@@ -42,9 +42,9 @@ Size of the packet `value` defined by `_fieldInfo` with context `rootNode`
 
 Returns a buffer of the `packet` for `type`.
 
-### ProtoDef.parsePacketBuffer(type,buffer)
+### ProtoDef.parsePacketBuffer(type,buffer,offset = 0)
 
-Returns a parsed packet of `buffer` for `type`.
+Returns a parsed packet of `buffer` for `type` starting at `offset`.
 
 ## Serializer(proto,mainType)
 

package.json

@@ -21,7 +21,7 @@
     "readable-stream": "^3.0.3"
   },
   "engines": {
-    "node": ">=6"
+    "node": ">=10.4"
   },
   "bugs": {
     "url": "https://github.com/ProtoDef-io/node-protodef/issues"
@@ -31,6 +31,11 @@
     "type": "git",
     "url": "https://github.com/ProtoDef-io/node-protodef.git"
   },
+  "standard": {
+    "ignore": [
+      "src/datatypes/numeric.js"
+    ]
+  },
   "devDependencies": {
     "benchmark": "^2.1.4",
     "chai": "^4.1.2",

src/compiler.js

@@ -95,8 +95,8 @@ class CompiledProtodef {
     return buffer
   }
 
-  parsePacketBuffer (type, buffer) {
-    const { value, size } = tryCatch(() => this.read(buffer, 0, type),
+  parsePacketBuffer (type, buffer, offset = 0) {
+    const { value, size } = tryCatch(() => this.read(buffer, offset, type),
       (e) => {
         e.message = `Read error for ${e.field} : ${e.message}`
         throw e

src/datatypes/numeric.js

@@ -1,58 +1,78 @@
 const { PartialReadError } = require('../utils')
 
+class BigIntExtended extends Array {
+  valueOf () { return BigInt.asIntN(64, BigInt(this[0]) << 32n) | BigInt.asUintN(32, BigInt(this[1])) }
+}
+
 function readI64 (buffer, offset) {
   if (offset + 8 > buffer.length) { throw new PartialReadError() }
   return {
-    value: [buffer.readInt32BE(offset), buffer.readInt32BE(offset + 4)],
+    value: new BigIntExtended(buffer.readInt32BE(offset), buffer.readInt32BE(offset + 4)),
     size: 8
   }
 }
 
 function writeI64 (value, buffer, offset) {
-  buffer.writeInt32BE(value[0], offset)
-  buffer.writeInt32BE(value[1], offset + 4)
+  if (typeof value === 'bigint') {
+    buffer.writeBigInt64BE(value, offset)
+  } else {
+    buffer.writeInt32BE(value[0], offset)
+    buffer.writeInt32BE(value[1], offset + 4)
+  }
   return offset + 8
 }
 
 function readLI64 (buffer, offset) {
   if (offset + 8 > buffer.length) { throw new PartialReadError() }
   return {
-    value: [buffer.readInt32LE(offset + 4), buffer.readInt32LE(offset)],
+    value: new BigIntExtended(buffer.readInt32LE(offset + 4), buffer.readInt32LE(offset)),
     size: 8
   }
 }
 
 function writeLI64 (value, buffer, offset) {
-  buffer.writeInt32LE(value[0], offset + 4)
-  buffer.writeInt32LE(value[1], offset)
+  if (typeof value === 'bigint') {
+    buffer.writeBigInt64LE(value, offset)
+  } else {
+    buffer.writeInt32LE(value[0], offset + 4)
+    buffer.writeInt32LE(value[1], offset)
+  }
   return offset + 8
 }
 
 function readU64 (buffer, offset) {
   if (offset + 8 > buffer.length) { throw new PartialReadError() }
   return {
-    value: [buffer.readUInt32BE(offset), buffer.readUInt32BE(offset + 4)],
+    value: new BigIntExtended(buffer.readUInt32BE(offset), buffer.readUInt32BE(offset + 4)),
     size: 8
   }
 }
 
 function writeU64 (value, buffer, offset) {
-  buffer.writeUInt32BE(value[0], offset)
-  buffer.writeUInt32BE(value[1], offset + 4)
+  if (typeof value === 'bigint') {
+    buffer.writeBigUInt64BE(value, offset)
+  } else {
+    buffer.writeUInt32BE(value[0], offset)
+    buffer.writeUInt32BE(value[1], offset + 4)
+  }
   return offset + 8
 }
 
 function readLU64 (buffer, offset) {
   if (offset + 8 > buffer.length) { throw new PartialReadError() }
   return {
-    value: [buffer.readUInt32LE(offset + 4), buffer.readUInt32LE(offset)],
+    value: new BigIntExtended(buffer.readUInt32LE(offset + 4), buffer.readUInt32LE(offset)),
     size: 8
   }
 }
 
 function writeLU64 (value, buffer, offset) {
-  buffer.writeUInt32LE(value[0], offset + 4)
-  buffer.writeUInt32LE(value[1], offset)
+  if (typeof value === 'bigint') {
+    buffer.writeBigUInt64LE(value, offset)
+  } else {
+    buffer.writeUInt32LE(value[0], offset + 4)
+    buffer.writeUInt32LE(value[1], offset)
+  }
   return offset + 8
 }
 

src/protodef.js

@@ -145,8 +145,8 @@ class ProtoDef {
     return buffer
   }
 
-  parsePacketBuffer (type, buffer) {
-    const { value, size } = tryCatch(() => this.read(buffer, 0, type, {}),
+  parsePacketBuffer (type, buffer, offset = 0) {
+    const { value, size } = tryCatch(() => this.read(buffer, offset, type, {}),
       (e) => {
         e.message = `Read error for ${e.field} : ${e.message}`
         throw e