序列化(Serialization)&protobuf

References:

• Serialization

What is Protobuf?

Protocol Buffers (Protobuf) is a language-agnostic, platform-neutral, and extensible mechanism for serializing structured data. It was developed by Google and is often used for communication between services or storage of structured data in an efficient binary format.

Protobuf is designed to be:

• Compact: Protobuf messages are serialized in a binary format, which is more efficient than text-based formats like XML or JSON. This leads to faster parsing and smaller message sizes.
• Fast: Because it uses a binary format, Protobuf is faster to serialize and deserialize compared to text-based formats like XML and JSON.
• Extensible: Protobuf allows you to add new fields to your data structures without breaking compatibility with old versions, making it ideal for maintaining backward compatibility as your system evolves.
• Language-agnostic: Protobuf provides code generation tools that can produce source code in multiple programming languages, such as C++, Java, Python, Go, and many more.

Protobuf vs XML/JSON:

Protobuf is a binary format, whereas XML and JSON are text-based formats. Here's a comparison between them:

Aspect	Protobuf	XML	JSON
Format	Binary (compact)	Text (verbose)	Text (human-readable)
Size	Small, efficient	Large and verbose	Larger than Protobuf, but more compact than XML
Speed	Very fast (due to binary format)	Slower (parsing text is time-consuming)	Faster than XML, but slower than Protobuf
Human Readable	No, it's binary	Yes, XML is human-readable	Yes, JSON is human-readable
Extensibility	Highly extensible (backward-compatible)	Moderate (requires special care to maintain backward compatibility)	Moderate (similar to XML in terms of compatibility)
Use Case	Efficient communication, storage	Data interchange, document formats	Data interchange, especially for APIs

Relationship with XML and JSON:

• Similarity:

  • Protobuf, XML, and JSON are all used for data serialization. This means they transform structured data (like objects or records) into a format that can be stored or transmitted (e.g., over a network).
  • They are language-independent, meaning you can use them with different programming languages. Protobuf offers tools to generate code for various languages, just like how XML and JSON are supported in most modern programming languages.

• Difference:

  • Human Readability: JSON and XML are human-readable and suitable for configurations, debugging, and direct user interaction. Protobuf is not human-readable because it is a binary format. This makes Protobuf less suitable for direct editing or debugging.
  • Efficiency: Protobuf is much more efficient in terms of size and speed because it uses a binary encoding, unlike XML and JSON which are both text-based and often verbose.
  • Schema: Protobuf uses a schema, which is defined using the .proto file format. This schema defines the structure of your data. With XML and JSON, there's no explicit schema, though XML can use DTD or XSD for schema validation.

Why use Protobuf?

• Performance: When you need high-performance serialization for applications that involve large volumes of data, such as microservices, IoT systems, or distributed systems, Protobuf is often the preferred choice.
• Cross-Language Support: Protobuf allows you to define your data schema once and then generate source code in multiple languages. This is helpful when different services in a system are written in different programming languages.
• Compact Size: For constrained environments, such as mobile apps or embedded systems, Protobuf's compact binary format reduces data transmission overhead.
• Backward and Forward Compatibility: The ability to evolve your data format without breaking backward compatibility is a key feature, especially for large systems where the schema changes over time.

When to use Protobuf vs XML/JSON?

• Use Protobuf when:

  • You need efficiency in terms of speed and size.
  • You have control over the schema and need a compact binary format.
  • You are working in a microservices architecture or other environments where performance and low overhead are critical.
  • You need to handle structured data with strong typing and enforce the schema.

• Use XML when:

  • You need extensibility and human-readable markup (e.g., documents or configurations).
  • You are working in environments where legacy systems are involved, or standards like SOAP are required.

• Use JSON when:

  • You need human-readable data exchange (for APIs, web services, etc.).
  • You prioritize ease of use and don't have strict performance requirements.

Example Use Cases for Protobuf:

• RPC communication: Protobuf is often used in gRPC, a high-performance RPC framework developed by Google. gRPC uses Protobuf as its default serialization format.
• Message queues: Protobuf is commonly used in systems like Kafka or RabbitMQ for efficient message serialization.
• Data storage: Protobuf can be used to store data in a binary format for faster read/write operations, particularly for large datasets.
• IoT systems: Protobuf is frequently used in IoT applications where low data overhead and efficiency are important due to limited bandwidth or storage.

Conclusion:

Protobuf is an efficient, extensible, and compact binary format for serializing structured data, and while it is related to XML and JSON in that it serves the same basic purpose (data serialization), it differs significantly in performance, size, and human-readability. It's a great choice when performance and data efficiency are key priorities.