| // 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 |
| // arguments. Tags always take exactly one byte. A serialized stream first |
| // begins with a complete VersionTag. If the stream does not begin with a |
| // VersionTag, we assume that the stream is in format 0. |
| |
| // This format is private to the implementation of SerializedScriptValue. Do not |
| // rely on it externally. It is safe to persist a SerializedScriptValue as a |
| // binary blob, but this code should always be used to interpret it. |
| |
| // WebCoreStrings are read as (length:uint32_t, string:UTF8[length]). |
| // RawStrings are read as (length:uint32_t, string:UTF8[length]). |
| // RawUCharStrings are read as |
| // (length:uint32_t, string:UChar[length/sizeof(UChar)]). |
| // RawFiles are read as |
| // (path:WebCoreString, url:WebCoreStrng, type:WebCoreString). |
| // There is a reference table that maps object references (uint32_t) to |
| // v8::Values. |
| // Tokens marked with (ref) are inserted into the reference table and given the |
| // next object reference ID after decoding. |
| // All tags except InvalidTag, PaddingTag, ReferenceCountTag, VersionTag, |
| // GenerateFreshObjectTag and GenerateFreshArrayTag push their results to the |
| // deserialization stack. |
| // There is also an 'open' stack that is used to resolve circular references. |
| // Objects or arrays may contain self-references. Before we begin to deserialize |
| // the contents of these values, they are first given object reference IDs (by |
| // GenerateFreshObjectTag/GenerateFreshArrayTag); these reference IDs are then |
| // used with ObjectReferenceTag to tie the recursive knot. |
| enum SerializationTag { |
| InvalidTag = '!', // Causes deserialization to fail. |
| PaddingTag = '\0', // Is ignored (but consumed). |
| UndefinedTag = '_', // -> <undefined> |
| NullTag = '0', // -> <null> |
| TrueTag = 'T', // -> <true> |
| FalseTag = 'F', // -> <false> |
| StringTag = 'S', // string:RawString -> string |
| StringUCharTag = 'c', // string:RawUCharString -> string |
| Int32Tag = 'I', // value:ZigZag-encoded int32 -> Integer |
| Uint32Tag = 'U', // value:uint32_t -> Integer |
| DateTag = 'D', // value:double -> Date (ref) |
| MessagePortTag = 'M', // index:int -> MessagePort. Fills the result with |
| // transferred MessagePort. |
| NumberTag = 'N', // value:double -> Number |
| BlobTag = 'b', // uuid:WebCoreString, type:WebCoreString, size:uint64_t -> |
| // Blob (ref) |
| BlobIndexTag = 'i', // index:int32_t -> Blob (ref) |
| FileTag = 'f', // file:RawFile -> File (ref) |
| FileIndexTag = 'e', // index:int32_t -> File (ref) |
| DOMFileSystemTag = 'd', // type:int32_t, name:WebCoreString, |
| // uuid:WebCoreString -> FileSystem (ref) |
| FileListTag = |
| 'l', // length:uint32_t, files:RawFile[length] -> FileList (ref) |
| FileListIndexTag = |
| 'L', // length:uint32_t, files:int32_t[length] -> FileList (ref) |
| ImageDataTag = '#', // width:uint32_t, height:uint32_t, |
| // pixelDataLength:uint32_t, data:byte[pixelDataLength] |
| // -> ImageData (ref) |
| // numProperties:uint32_t -> pops the last object from the open stack; fills |
| // it with the last numProperties name,value pairs pushed onto the |
| // deserialization stack |
| ObjectTag = '{', |
| // numProperties:uint32_t, length:uint32_t -> pops the last object from the |
| // open stack; fills it with the last numProperties name,value pairs pushed |
| // onto the deserialization stack |
| SparseArrayTag = '@', |
| // numProperties:uint32_t, length:uint32_t -> pops the last object from the |
| // open stack; fills it with the last length elements and numProperties |
| // name,value pairs pushed onto deserialization stack |
| DenseArrayTag = '$', |
| RegExpTag = 'R', // pattern:RawString, flags:uint32_t -> RegExp (ref) |
| ArrayBufferTag = |
| 'B', // byteLength:uint32_t, data:byte[byteLength] -> ArrayBuffer (ref) |
| ArrayBufferTransferTag = |
| 't', // index:uint32_t -> ArrayBuffer. For ArrayBuffer transfer |
| ImageBitmapTag = 'g', // size:uint32_t, data:byte[size] -> ImageBitmap (ref) |
| ImageBitmapTransferTag = |
| 'G', // index:uint32_t -> ImageBitmap. For ImageBitmap transfer |
| OffscreenCanvasTransferTag = 'H', // index, width, height, id:uint32_t -> |
| // OffscreenCanvas. For OffscreenCanvas |
| // transfer |
| // subtag:byte, byteOffset:uint32_t, byteLength:uint32_t -> ArrayBufferView |
| // (ref). Consumes an ArrayBuffer from the top of the deserialization stack. |
| ArrayBufferViewTag = 'V', |
| SharedArrayBufferTransferTag = 'u', // index:uint32_t -> SharedArrayBuffer. |
| // For SharedArrayBuffer transfer |
| WasmModuleTag = 'W', |
| CryptoKeyTag = '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 |
| RTCCertificateTag = 'k', // length:uint32_t, pemPrivateKey:WebCoreString, |
| // pemCertificate:WebCoreString |
| ObjectReferenceTag = '^', // ref:uint32_t -> reference table[ref] |
| GenerateFreshObjectTag = 'o', // -> empty object allocated an object ID and |
| // pushed onto the open stack (ref) |
| GenerateFreshSparseArrayTag = 'a', // length:uint32_t -> empty array[length] |
| // allocated an object ID and pushed onto |
| // the open stack (ref) |
| GenerateFreshDenseArrayTag = 'A', // length:uint32_t -> empty array[length] |
| // allocated an object ID and pushed onto |
| // the open stack (ref) |
| ReferenceCountTag = '?', // refTableSize:uint32_t -> If the reference table |
| // is not refTableSize big, fails. |
| StringObjectTag = 's', // string:RawString -> new String(string) (ref) |
| NumberObjectTag = 'n', // value:double -> new Number(value) (ref) |
| TrueObjectTag = 'y', // new Boolean(true) (ref) |
| FalseObjectTag = 'x', // new Boolean(false) (ref) |
| CompositorProxyTag = |
| 'C', // elementId:uint64_t, bitfields:uint32_t -> CompositorProxy (ref) |
| MapTag = ':', // length:uint32_t -> pops the last object from the open stack |
| // (it will be a Map); |
| // fills it with the last length elements pushed |
| // onto the deserialization stack, treating them |
| // as key/value pairs and passing them to |
| // Map::Set; |
| // length must be an even number. |
| SetTag = ',', // length:uint32_t -> pops the last object from the open stack |
| // (it will be a Set); |
| // fills it with the last length elements pushed |
| // onto the deserialization stack, using Set::Add |
| GenerateFreshMapTag = ';', // -> empty Map allocated an object ID and pushed |
| // onto the open stack (ref) |
| GenerateFreshSetTag = '\'', // -> empty Set allocated an object ID and pushed |
| // onto the open stack (ref) |
| VersionTag = 0xFF // version:uint32_t -> Uses this as the file version. |
| }; |
| |
| enum ArrayBufferViewSubTag { |
| ByteArrayTag = 'b', |
| UnsignedByteArrayTag = 'B', |
| UnsignedByteClampedArrayTag = 'C', |
| ShortArrayTag = 'w', |
| UnsignedShortArrayTag = 'W', |
| IntArrayTag = 'd', |
| UnsignedIntArrayTag = 'D', |
| FloatArrayTag = 'f', |
| DoubleArrayTag = 'F', |
| DataViewTag = '?' |
| }; |
| |
| } // namespace blink |
| |
| #endif |
