Serialization is the process of storing the state of an object to a storage medium. In binary serialization, the public and private fields of the object and the name of the class, including the assembly containing the class, are converted to a stream of bytes, which is then written to a data stream. When the object is subsequently deserialized, an exact clone of the original object is created.
When implementing a serialization mechanism in an object-oriented environment, you often need to make tradeoffs between ease of use and flexibility. The process can be automated to a large extent, provided you are given sufficient control over the process. For example, situations may arise where simple binary serialization is not sufficient, or there might be a specific reason to decide which fields in a class need to be serialized. The following sections examine the robust serialization mechanism provided with .NET and highlight a number of important features that allow you to customize the process to meet your needs.
c serialize object to binary file
During RPCs, the IRemotingFormatter interface allows the specification of two separate object graphs: the graph of objects to serialize, and an additional graph that contains an array of header objects that convey information about the remote function call (for example, transaction ID or a method signature).
During serialization of a method call the first object of the object graph must support the IMethodCallMessage interface. To deserialize a method call, use the Deserialize method with the HeaderHandler parameter. The remoting infrastructure uses the HeaderHandler delegate to produce an object that supports the ISerializable interface. When the BinaryFormatter invokes the HeaderHandler delegate, it returns the URI of the remote object with the method that is being called. The first object in the graph returned supports the IMethodCallMessage interface.
The serialization procedure for a method response is identical to that of a method call, except the first object of the object graph must support the IMethodReturnMessage interface. To deserialize a method response, use the DeserializeMethodResponse method. To save time, details about the caller object are not sent to the remote object during the method call. These details are instead obtained from the original method call, which is passed to the DeserializeMethodResponse method in the IMethodCallMessage parameter. The first object in the graph returned by the DeserializeMethodResponse method supports the IMethodReturnMessage interface.
Serialization is the process of converting an object into a stream of bytes to store the object or transmit it to memory, a database, or a file. Its main purpose is to save the state of an object in order to be able to recreate it when needed. The reverse process is called deserialization.
The object is serialized to a stream that carries the data. The stream may also have information about the object's type, such as its version, culture, and assembly name. From that stream, the object can be stored in a database, a file, or memory.
JSON serialization serializes the public properties of an object into a string, byte array, or stream that conforms to the RFC 8259 JSON specification. To control the way JsonSerializer serializes or deserializes an instance of the class, you can use one or more of the following approaches:
Binary serialization uses binary encoding to produce compact serialization for uses such as storage or socket-based network streams. In binary serialization, all members, even members that are read-only, are serialized, and performance is enhanced.
XML serialization serializes the public fields and properties of an object, or the parameters and return values of methods, into an XML stream that conforms to a specific XML Schema definition language (XSD) document. XML serialization results in strongly typed classes with public properties and fields that are converted to XML. System.Xml.Serialization contains classes for serializing and deserializing XML. You apply attributes to classes and class members to control the way the XmlSerializer serializes or deserializes an instance of the class.
Basic serialization uses .NET to automatically serialize the object. The only requirement is that the class has the SerializableAttribute attribute applied. The NonSerializedAttribute can be used to keep specific fields from being serialized.
In custom serialization, you can specify exactly which objects will be serialized and how it will be done. The class must be marked SerializableAttribute and implement the ISerializable interface. If you want your object to be deserialized in a custom manner as well, use a custom constructor.
Designer serialization is a special form of serialization that involves the kind of object persistence associated with development tools. Designer serialization is the process of converting an object graph into a source file that can later be used to recover the object graph. A source file can contain code, markup, or even SQL table information.
The binary file would contain the bit representation of your object, and this is not portable to another computer, or even to another process running the same program (notably because of ASLR) unless your object is a POD.
You probably want some serialization. Since disks and file accesses are a lot slower (many dozen of thousands slower) than the CPU, it is often wise to use some more portable data representation. Practically speaking, you should consider some textual representation like e.g. JSON, XML, YAML etc.... Libraries such as jsoncpp are really easy to use, and you'll need to code something to transform your object into some JSON, and to create some object from a JSON.
This has implications both for recursive objects and object sharing. Recursiveobjects are objects that contain references to themselves. These are nothandled by marshal, and in fact, attempting to marshal recursive objects willcrash your Python interpreter. Object sharing happens when there are multiplereferences to the same object in different places in the object hierarchy beingserialized. pickle stores such objects only once, and ensures that allother references point to the master copy. Shared objects remain shared, whichcan be very important for mutable objects.
marshal cannot be used to serialize user-defined classes and theirinstances. pickle can save and restore class instances transparently,however the class definition must be importable and live in the same module aswhen the object was stored.
Serialization is a more primitive notion than persistence; althoughpickle reads and writes file objects, it does not handle the issue ofnaming persistent objects, nor the (even more complicated) issue of concurrentaccess to persistent objects. The pickle module can transform a complexobject into a byte stream and it can transform the byte stream into an objectwith the same internal structure. Perhaps the most obvious thing to do withthese byte streams is to write them onto a file, but it is also conceivable tosend them across a network or store them in a database. The shelvemodule provides a simple interface to pickle and unpickle objects onDBM-style database files.
To serialize an object hierarchy, you simply call the dumps() function.Similarly, to de-serialize a data stream, you call the loads() function.However, if you want more control over serialization and de-serialization,you can create a Pickler or an Unpickler object, respectively.
The file argument must have a write() method that accepts a single bytesargument. It can thus be an on-disk file opened for binary writing, anio.BytesIO instance, or any other custom object that meets thisinterface.
The argument file must have three methods, a read() method that takes aninteger argument, a readinto() method that takes a buffer argumentand a readline() method that requires no arguments, as in theio.BufferedIOBase interface. Thus file can be an on-disk fileopened for binary reading, an io.BytesIO object, or any othercustom object that meets this interface.
Read the pickled representation of an object from the open file objectgiven in the constructor, and return the reconstituted object hierarchyspecified therein. Bytes past the pickled representation of the objectare ignored.
Attempts to pickle unpicklable objects will raise the PicklingErrorexception; when this happens, an unspecified number of bytes may have alreadybeen written to the underlying file. Trying to pickle a highly recursive datastructure may exceed the maximum recursion depth, a RecursionError will beraised in this case. You can carefully raise this limit withsys.setrecursionlimit().
A few days back I discussed XML Serialization in these two articles: Basic XML Serialization in C#, and XML Serialization of Collections. In this article we are going to serialize the same Employee object we serialized in those articles, but this time we are going to use Binary serialization instead.
You might think that binary serialization and XML serialization are the same thing, the only difference being the format of the data within the created file. Well if that is the case, you would be wrong.
This statement can obviously be proven by opening the file of a binary serialized object with a hex editor and verifying that the private properties of the object are there, but since it is a binary file that could prove a bit problematic to read for the majority of us :).
All we are doing in this code is creating an instance of our Employee class and populating some values, then we are creating a FileStream object to write our serialized file, and finally we are using the BinaryFormatter class to serialize our object.
The below screenshot is displaying the Visual Studio Locals window and you can see the employee object after the deserialization process which confirms that the binary file was deserialized correctly.
Serialization is the process of converting an object into a stream of bytes to store the object or transmit it to memory, a database, a file, or across a network. Its main purpose is to save the state of an object in order to be able to recreate it when needed. The reverse process is called deserialization. 2ff7e9595c
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