Implement serialization/deserialization of geometry interfaces

third_party/WebKit/Source/bindings/core/v8/serialization/SerializationTag.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SerializationTag_h
 #define SerializationTag_h
 
 namespace blink {
 
 // Serialization format is a sequence of tags followed by zero or more data
@@ skipping 41 matching lines @@
       'L',  // length:uint32_t, files:int32_t[length] -> FileList (ref)
   kImageDataTag = '#',  // width:uint32_t, height:uint32_t,
                         // pixelDataLength:uint32_t, data:byte[pixelDataLength]
                         // -> ImageData (ref)
   kImageBitmapTag = 'g',  // size:uint32_t, data:byte[size] -> ImageBitmap (ref)
   kImageBitmapTransferTag =
       'G',  // index:uint32_t -> ImageBitmap. For ImageBitmap transfer
   kOffscreenCanvasTransferTag = 'H',  // index, width, height, id:uint32_t ->
                                       // OffscreenCanvas. For OffscreenCanvas
                                       // transfer
-  kCryptoKeyTag = 'K',                // subtag:byte, props, usages:uint32_t,
+  kDOMPointTag = 'Q',                 // x:Double, y:Double, z:Double, w:Double

[jbroman, 2017/05/15 17:02:54]

At times like these I wish we had just used consecutive integers (but it's a
pain to come up with new ones).

Some of these do collide with the V8-side tags (e.g. U and I were integers), but
this prime real estate is now available due to V8 explicitly labelling Blink
objects.

[fserb, 2017/05/15 17:52:16]

Do those need to be printable chars? Or could I create a CL that just make every
single one of those a number?

[jbroman, 2017/05/15 18:00:30]

They don't need to be printable, no. But the existing tags do need to be the
same as they were in the past, because this data is persisted to disk. So we
could change them all to decimal/hexadecimal constants and encourage people to
fill up the rest from the bottom up, but it's still left looking kinda strange.

+  kDOMPointReadOnlyTag = 'W',         // x:Double, y:Double, z:Double, w:Double
+  kDOMRectTag = 'E',          // x:Double, y:Double, width:Double, height:Double
+  kDOMRectReadOnlyTag = 'R',  // x:Double, y:Double, width:Double, height:Double
+  kDOMQuadTag = 'T',          // p1:Double, p2:Double, p3:Double, p4:Double
+  kDOMMatrixTag = 'Y',        // m11..m44: 16 Double
+  kDOMMatrixReadOnlyTag = 'U',    // m11..m44: 16 Double
+  kDOMMatrix2DTag = 'I',          // a..f: 6 Double
+  kDOMMatrix2DReadOnlyTag = 'O',  // a..f: 6 Double
+  kCryptoKeyTag = 'K',            // subtag:byte, props, usages:uint32_t,
                         // keyDataLength:uint32_t, keyData:byte[keyDataLength]
   //                 If subtag=AesKeyTag:
   //                     props = keyLengthBytes:uint32_t, algorithmId:uint32_t
   //                 If subtag=HmacKeyTag:
   //                     props = keyLengthBytes:uint32_t, hashId:uint32_t
   //                 If subtag=RsaHashedKeyTag:
   //                     props = algorithmId:uint32_t, type:uint32_t,
   //                     modulusLengthBits:uint32_t,
   //                     publicExponentLength:uint32_t,
   //                     publicExponent:byte[publicExponentLength],
   //                     hashId:uint32_t
   //                 If subtag=EcKeyTag:
   //                     props = algorithmId:uint32_t, type:uint32_t,
   //                     namedCurve:uint32_t
   kRTCCertificateTag = 'k',  // length:uint32_t, pemPrivateKey:WebCoreString,
                              // pemCertificate:WebCoreString
   kCompositorProxyTag =
       'C',  // elementId:uint64_t, bitfields:uint32_t -> CompositorProxy (ref)
   kVersionTag = 0xFF  // version:uint32_t -> Uses this as the file version.
 };
 
 }  // namespace blink
 
 #endif