added raw buffer type

asbaker · Jul 29, 2014 · 6186d7c · 6186d7c
1 parent 1610979
commit 6186d7c
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # CHANGELOG
 
+## 0.4.0 (2013-03-26)
+- Added default value field
+
 ## 0.3.2 (2013-03-24)
 - Performance improvements for field encoding, write to the same buffer when encoding fields
 

diff --git a/README.md b/README.md
@@ -35,6 +35,7 @@ The Javascript object specification is used to specify endianness and a descript
         {name: "field12", start: 38, type: 'uint32'},
         {name: "field13", start: 42, type: 'int32'}
         {name: "field14", start: 46, type: 'int8', default: 42 }
+        {name: "field15", start: 50, type: 'buffer', length: 4 }
     ]
 }
 
@@ -44,6 +45,7 @@ The Javascript object specification is used to specify endianness and a descript
 All fields must have a name, a starting byte, and a type. The name is used for assigning the property in the resulting javascript object. Additionally, fields can have a default value which is used when encoding an object's properties that have null or undefined values.
 
 #### Types
+* **buffer** - Raw buffer
 * **int8** - Signed 8-bit integer
 * **uint8** - Unsigned 8-bit integer
 * **int16** - Signed 16-bit integer
@@ -74,23 +76,26 @@ All fields must have a name, a starting byte, and a type. The name is used for a
 ### Example
 
 ```javascript
-var DecoderRing = require("decoder-ring")
+var DecoderRing = require("decoder-ring");
 var decoderRing = new DecoderRing();
 
-var bufferBE = new Buffer(47)
-bufferBE.fill(0)
-bufferBE.writeInt8(-127, 0)
-bufferBE.writeUInt8(254, 1)
-bufferBE.writeInt16BE(5327, 2)
-bufferBE.writeUInt16BE(5328, 4)
-bufferBE.writeFloatBE(-15.33, 6)
-bufferBE.writeDoubleBE(-1534.98, 10)
-bufferBE.write("ascii", 18, 10,'ascii')
-bufferBE.write("utf8 text", 28, 9, 'utf8')
-bufferBE.writeUInt8(129, 37)
-bufferBE.writeUInt32BE(79001, 38)
-bufferBE.writeInt32BE(-79001, 42)
-bufferBE.writeInt8(1, 46)
+var bufferBE = new Buffer(51);
+bufferBE.fill(0);
+bufferBE.writeInt8(-127, 0);
+bufferBE.writeUInt8(254, 1);
+bufferBE.writeInt16BE(5327, 2);
+bufferBE.writeUInt16BE(5328, 4);
+bufferBE.writeFloatBE(-15.33, 6);
+bufferBE.writeDoubleBE(-1534.98, 10);
+bufferBE.write("ascii", 18, 10,'ascii');
+bufferBE.write("utf8 text", 28, 9, 'utf8');
+bufferBE.writeUInt8(129, 37);
+bufferBE.writeUInt32BE(79001, 38);
+bufferBE.writeInt32BE(-79001, 42);
+bufferBE.writeInt8(1, 46);
+
+var testBuffer = new Buffer("test");
+testBuffer.copy(bufferBE, 47, 0, 4);
 
 var spec = {
   bigEndian: true,
@@ -101,37 +106,39 @@ var spec = {
     { name: "field4", start: 4,   type: 'uint16'},
     { name: "field5", start: 6,   type: 'float' },
     { name: "field6", start: 10,  type: 'double'},
-    { name: "field7", start: 18,  type: 'ascii',length: 10 },
+    { name: "field7", start: 18,  type: 'ascii', length: 10 },
     { name: "field8", start: 28,  type: 'utf8', length: 9  },
     { name: "field9", start: 37,  type: 'bit', position: 7 },
     { name: "field10", start: 37, type: 'bit', position: 6 },
     { name: "field11", start: 37, type: 'bit', position: 0 },
     { name: "field12", start: 38, type: 'uint32' },
     { name: "field13", start: 42, type: 'int32' },
-    { name: "field14", start: 46, type: 'int8', default: 42 }
+    { name: "field14", start: 46, type: 'int8', default: 42 },
+    { name: "field15", start: 47, type: 'buffer', length: 4 }
   ]
-}
+};
 
 // Decode the buffer into a javascript object
-var result = decoderRing.decode(bufferBE, spec)
-console.log(result)
+var result = decoderRing.decode(bufferBE, spec);
+console.log(result);
 
 // Assign field14 to undefined to test default value on encoding
-result.field14 = undefined
+result.field14 = undefined;
 
 // Encode the object to a buffer
-var buffer = decoderRing.encode(result, spec)
-console.log(buffer)
+var buffer = decoderRing.encode(result, spec);
+console.log(buffer);
 
 // Decode buffer to object and check field14 for default value
-var resultWithDefaultValue = decoderRing.decode(buffer, spec)
-console.log("Field14 default value: " + resultWithDefaultValue.field14)
+var resultWithDefaultValue = decoderRing.decode(buffer, spec);
+console.log("Field14 default value: " + resultWithDefaultValue.field14);
 ```
 
 Result of the above example
 
 ```javascript
-{ field1: -127,
+{ 
+  field1: -127,
   field2: 254,
   field3: 5327,
   field4: 5328,
@@ -144,7 +151,9 @@ Result of the above example
   field11: true,
   field12: 79001,
   field13: -79001,
-  field14: 1 }
+  field14: 1,
+  field15: <Buffer 74 65 73 74> 
+}
 
 <Buffer 81 fe 14 cf 14 d0 c1 75 47 ae c0 97 fb eb 85 1e b8 52 61 73 63 69 69 20 20 20 20 20 75 74 66 38 20 74 65 78 74 81 00 01 34 99 ff fe cb 67 2a>
 

diff --git a/example.js b/example.js
@@ -1,20 +1,23 @@
-var DecoderRing = require("decoder-ring")
+var DecoderRing = require("decoder-ring");
 var decoderRing = new DecoderRing();
 
-var bufferBE = new Buffer(47)
-bufferBE.fill(0)
-bufferBE.writeInt8(-127, 0)
-bufferBE.writeUInt8(254, 1)
-bufferBE.writeInt16BE(5327, 2)
-bufferBE.writeUInt16BE(5328, 4)
-bufferBE.writeFloatBE(-15.33, 6)
-bufferBE.writeDoubleBE(-1534.98, 10)
-bufferBE.write("ascii", 18, 10,'ascii')
-bufferBE.write("utf8 text", 28, 9, 'utf8')
-bufferBE.writeUInt8(129, 37)
-bufferBE.writeUInt32BE(79001, 38)
-bufferBE.writeInt32BE(-79001, 42)
-bufferBE.writeInt8(1, 46)
+var bufferBE = new Buffer(51);
+bufferBE.fill(0);
+bufferBE.writeInt8(-127, 0);
+bufferBE.writeUInt8(254, 1);
+bufferBE.writeInt16BE(5327, 2);
+bufferBE.writeUInt16BE(5328, 4);
+bufferBE.writeFloatBE(-15.33, 6);
+bufferBE.writeDoubleBE(-1534.98, 10);
+bufferBE.write("ascii", 18, 10,'ascii');
+bufferBE.write("utf8 text", 28, 9, 'utf8');
+bufferBE.writeUInt8(129, 37);
+bufferBE.writeUInt32BE(79001, 38);
+bufferBE.writeInt32BE(-79001, 42);
+bufferBE.writeInt8(1, 46);
+
+var testBuffer = new Buffer("test");
+testBuffer.copy(bufferBE, 47, 0, 4);
 
 var spec = {
   bigEndian: true,
@@ -25,28 +28,30 @@ var spec = {
     { name: "field4", start: 4,   type: 'uint16'},
     { name: "field5", start: 6,   type: 'float' },
     { name: "field6", start: 10,  type: 'double'},
-    { name: "field7", start: 18,  type: 'ascii',length: 10 },
+    { name: "field7", start: 18,  type: 'ascii', length: 10 },
     { name: "field8", start: 28,  type: 'utf8', length: 9  },
     { name: "field9", start: 37,  type: 'bit', position: 7 },
     { name: "field10", start: 37, type: 'bit', position: 6 },
     { name: "field11", start: 37, type: 'bit', position: 0 },
     { name: "field12", start: 38, type: 'uint32' },
     { name: "field13", start: 42, type: 'int32' },
-    { name: "field14", start: 46, type: 'int8', default: 42 }
+    { name: "field14", start: 46, type: 'int8', default: 42 },
+    { name: "field15", start: 47, type: 'buffer', length: 4 }
   ]
-}
+};
 
 // Decode the buffer into a javascript object
-var result = decoderRing.decode(bufferBE, spec)
-console.log(result)
+var result = decoderRing.decode(bufferBE, spec);
+console.log(result);
 
 // Assign field14 to undefined to test default value on encoding
-result.field14 = undefined
+result.field14 = undefined;
 
 // Encode the object to a buffer
-var buffer = decoderRing.encode(result, spec)
-console.log(buffer)
+var buffer = decoderRing.encode(result, spec);
+console.log(buffer);
 
 // Decode buffer to object and check field14 for default value
-var resultWithDefaultValue = decoderRing.decode(buffer, spec)
-console.log("Field14 default value: " + resultWithDefaultValue.field14)
+var resultWithDefaultValue = decoderRing.decode(buffer, spec);
+console.log("Field14 default value: " + resultWithDefaultValue.field14);
+
diff --git a/src/FieldDecoder.coffee b/src/FieldDecoder.coffee
@@ -11,6 +11,7 @@ class FieldDecoder
       when 'double' then buffer.readDoubleBE(fieldSpec.start)
       when 'ascii'  then buffer.toString('ascii', fieldSpec.start, fieldSpec.start+fieldSpec.length)
       when 'utf8'   then buffer.toString('utf8', fieldSpec.start, fieldSpec.start+fieldSpec.length)
+      when 'buffer' then buffer.slice(fieldSpec.start, fieldSpec.start+fieldSpec.length)
       when 'bit'
         i = buffer.readUInt8(fieldSpec.start)
         (i & Math.pow(2, fieldSpec.position)) > 0
@@ -28,6 +29,7 @@ class FieldDecoder
       when 'double' then buffer.readDoubleLE(fieldSpec.start)
       when 'ascii'  then buffer.toString('ascii', fieldSpec.start, fieldSpec.start+fieldSpec.length)
       when 'utf8'   then buffer.toString('utf8', fieldSpec.start, fieldSpec.start+fieldSpec.length)
+      when 'buffer' then buffer.slice(fieldSpec.start, fieldSpec.start+fieldSpec.length)
       when 'bit'
         i = buffer.readUInt8(fieldSpec.start)
         (i & Math.pow(2, fieldSpec.position)) > 0

diff --git a/src/FieldEncoder.coffee b/src/FieldEncoder.coffee
@@ -13,7 +13,7 @@ class FieldEncoder
       when 'int16', 'uint16'          then 2
       when 'uint32', 'int32', 'float' then 4
       when 'double'                   then 8
-      when 'ascii', 'utf8'            then field.length
+      when 'ascii', 'utf8', 'buffer'  then field.length
 
     return field.start + length
 
@@ -36,6 +36,7 @@ class FieldEncoder
         when 'utf8'   then buffer.write(val, fieldSpec.start, fieldSpec.length, 'utf8')
         when 'uint32' then buffer.writeUInt32BE(val, fieldSpec.start)
         when 'int32'  then buffer.writeInt32BE(val, fieldSpec.start)
+        when 'buffer' then val.copy(buffer, fieldSpec.start, 0, fieldSpec.length)
         when 'bit'
           if val is true # protection from type problems
             buffer.writeUInt8(Math.pow(2, fieldSpec.position), fieldSpec.start)
@@ -63,6 +64,7 @@ class FieldEncoder
         when 'utf8'   then buffer.write(val, fieldSpec.start, fieldSpec.length, 'utf8')
         when 'uint32' then buffer.writeUInt32LE(val, fieldSpec.start)
         when 'int32'  then buffer.writeInt32LE(val, fieldSpec.start)
+        when 'buffer' then val.copy(buffer, fieldSpec.start, 0, fieldSpec.length)
         when 'bit'
           if val is true # protection from type problems
             buffer.writeUInt8(Math.pow(2, fieldSpec.position), fieldSpec.start)

diff --git a/test/DecoderRingIntegrationTest.coffee b/test/DecoderRingIntegrationTest.coffee
@@ -28,6 +28,7 @@ describe "BinaryDecoderRing Integration Test", ->
       expect(result.field11).to.be.true
       expect(result.field12).to.equal(79001)
       expect(result.field13).to.equal(-79001)
+      expect(result.field14).to.eql(new Buffer("test"))
 
     it "decodes little endian specifications", ->
       result = @subject.decode(@bufferLE, @bufferLESpec)
@@ -45,6 +46,7 @@ describe "BinaryDecoderRing Integration Test", ->
       expect(result.field11).to.be.true
       expect(result.field12).to.equal(79002)
       expect(result.field13).to.equal(-79002)
+      expect(result.field14).to.eql(new Buffer("test"))
 
   describe "#encode", ->
     it "encodes big endian specifications", ->

diff --git a/test/FieldDecoderUnitTest.coffee b/test/FieldDecoderUnitTest.coffee
@@ -70,6 +70,11 @@ describe "FieldDecoder unit test", ->
       result = @subject.decodeFieldBE(@bufferBE, fieldSpec)
       expect(result).to.equal(-79001)
 
+    it "decodes a buffer field", ->
+      fieldSpec = {name: "foo", start: 46, type: 'buffer', length: 4}
+      result = @subject.decodeFieldBE(@bufferBE, fieldSpec)
+      expect(result).to.eql(new Buffer("test"))
+
 
   describe "#decodeFieldLE", ->
     it "decodes an int8 field", ->
@@ -127,3 +132,8 @@ describe "FieldDecoder unit test", ->
       result = @subject.decodeFieldLE(@bufferLE, fieldSpec)
       expect(result).to.equal(-79002)
 
+    it "decodes a buffer field", ->
+      fieldSpec = {name: "foo", start: 46, type: 'buffer', length: 4}
+      result = @subject.decodeFieldLE(@bufferLE, fieldSpec)
+      expect(result).to.eql(new Buffer("test"))
+
diff --git a/test/FieldEncoderUnitTest.coffee b/test/FieldEncoderUnitTest.coffee
@@ -215,6 +215,18 @@ describe "FieldEncoder unit test", ->
       result = @subject.encodeFieldBE(outBuffer, obj, fieldSpec)
       expect(result).to.deep.equal(expectedBuffer)
 
+    it "encodes a buffer field", ->
+      expectedBuffer = new Buffer("testing")
+
+      outBuffer = new Buffer(7)
+      outBuffer.fill(0)
+
+      obj = {field8: expectedBuffer}
+      fieldSpec = {name: "field8", start: 0, type: 'buffer', length: 7}
+
+      result = @subject.encodeFieldBE(outBuffer, obj, fieldSpec)
+      expect(result).to.deep.equal(expectedBuffer)
+
   describe "#encodeFieldLE", ->
     it "will use the default default value according to the fieldSpec when property is undefined", ->
       expectedBuffer = new Buffer(2)
@@ -410,6 +422,19 @@ describe "FieldEncoder unit test", ->
       result = @subject.encodeFieldLE(outBuffer, obj, fieldSpec)
       expect(result).to.deep.equal(expectedBuffer)
 
+    it "encodes a buffer field", ->
+      expectedBuffer = new Buffer("testing")
+
+      outBuffer = new Buffer(7)
+      outBuffer.fill(0)
+
+      obj = {field8: expectedBuffer}
+      fieldSpec = {name: "field8", start: 0, type: 'buffer', length: 7}
+
+      result = @subject.encodeFieldLE(outBuffer, obj, fieldSpec)
+      expect(result).to.deep.equal(expectedBuffer)
+
+
   describe "#findFieldLength", ->
     it "works for int8's", ->
       field = {name: "field1", start: 2,  type: 'int8'  }
@@ -471,9 +496,15 @@ describe "FieldEncoder unit test", ->
       result = @subject.findFieldLength(field)
       expect(result).to.equal(3)
 
+    it "works for buffers", ->
+      field = {name: "field1", start: 2,  type: 'buffer', length: 3 }
+
+      result = @subject.findFieldLength(field)
+      expect(result).to.equal(5)
+
   describe "#findSpecBufferSize", ->
     it "finds the max size of a buffer", ->
       result = @subject.findSpecBufferSize(@bufferLESpec)
-      expect(result).to.equal(46)
+      expect(result).to.equal(50)
 
 
diff --git a/test/Fixtures.coffee b/test/Fixtures.coffee
@@ -10,6 +10,7 @@ bufferBE.write("utf8 text", 28, 9, 'utf8')
 bufferBE.writeUInt8(129, 37)
 bufferBE.writeUInt32BE(79001, 38)
 bufferBE.writeInt32BE(-79001, 42)
+bufferBE = Buffer.concat([bufferBE, new Buffer("test")])
 
 bufferLE = new Buffer(46)
 bufferLE.writeInt8(-127, 0)
@@ -23,6 +24,7 @@ bufferLE.write("utf8 text", 28, 9, 'utf8')
 bufferLE.writeUInt8(129, 37)
 bufferLE.writeUInt32LE(79002, 38)
 bufferLE.writeInt32LE(-79002, 42)
+bufferLE = Buffer.concat([bufferLE, new Buffer("test")])
 
 bufferBESpec = {
   bigEndian: true
@@ -40,6 +42,7 @@ bufferBESpec = {
     {name: "field11", start: 37, type: 'bit', position: 0}
     {name: "field12", start: 38, type: 'uint32'}
     {name: "field13", start: 42, type: 'int32'}
+    {name: "field14", start: 46, type: 'buffer', length: 4 }
   ]
 }
 
@@ -59,6 +62,7 @@ bufferLESpec = {
     {name: "field11", start: 37, type: 'bit', position: 0}
     {name: "field12", start: 38, type: 'uint32'}
     {name: "field13", start: 42, type: 'int32'}
+    {name: "field14", start: 46, type: 'buffer', length: 4 }
   ]
 }