Wire & Proto3

Starting in 3.3.0 Wire supports Proto3. What changes with Proto3? How does Wire make it comfortable to use? Let’s see.

Transcript

1. WIRE & Proto3
   @bquenaudon
   

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4. Identity if absent
   

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5. syntax = "proto2";
   message Message {
   required string a = 1;
   optional string b = 2;
   }
   

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6. syntax = "proto2";
   message Message {
   required string a = 1;
   optional string b = 2;
   }
   

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7. syntax = "proto3";
   message Message {
   string a = 1;
   }
   

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8. syntax = "proto3";
   message Message {
   string a = 1;
   optional string b = 2;
   }
   

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9. syntax = "proto3";
   message Message {
   string a = 1;
   optional string b = 2;
   }
   

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10. Identity if absent
    Strings → ""
    Bytes → empty bytes
    Bools → false
    Numerics → 0, 0L, 0f, 0.0
    Enums → first defined value (which must be 0)
    Messages → Null
    

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11. syntax = "proto2";
    message MyMessage {
    required string a = 1;
    optional string b = 2;
    }
    class MyMessage(
    val a: String,
    val b: String? = null
    ) : Message() {}
    →
    

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12. syntax = "proto3";
    message MyMessage {
    string a = 1;
    optional string b = 2;
    }
    class MyMessage(
    val a: String = "",
    val b: String? = null
    ) : Message() {}
    →
    

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13. New Types
    

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14. Any → com.squareup.wire.AnyMessage
    Duration → java.time.Duration
    Timestamp → java.time.Instant
    Struct → map
    Wrappers → Boxed types for primitives (String?)
    Empty → kotlin.Unit
    New Types
    google.protobuf.
    

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15. message Request {
    // Only set when it is a Bitcoin request.
    optional BitcoinData bitcoin_data = 1;
    // Only set when it is a Stock request.
    optional StockData stock_data = 2;
    }
    

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16. message Request {
    // Only set when it is a Bitcoin request.
    optional BitcoinData bitcoin_data = 1;
    // Only set when it is a Stock request.
    optional StockData stock_data = 2;
    }
    message Request {
    // Will be either BitcoinData or StockData.
    optional google.protobuf.Any request_data = 1;
    }
    ↓
    

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17. Any → com.squareup.wire.AnyMessage
    Duration → java.time.Duration
    Timestamp → java.time.Instant
    Struct → map
    Wrappers → Boxed types for primitives (String?)
    Empty → kotlin.Unit
    New Types
    google.protobuf.
    

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18. Any → com.squareup.wire.AnyMessage
    Duration → java.time.Duration
    Timestamp → java.time.Instant
    Struct → map
    Wrappers → Boxed types for primitives (String?)
    Empty → kotlin.Unit
    New Types
    google.protobuf.
    

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19. class AnyMessage(
    val typeUrl: String,
    val value: ByteString = ByteString.EMPTY
    ) : Message(ADAPTER, ByteString.EMPTY) {
    fun unpack(adapter: ProtoAdapter): T
    fun unpackOrNull(adapter: ProtoAdapter): T?
    companion object {
    fun pack(message: Message<*, *>): AnyMessage
    }
    }
    

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20. class AnyMessage(
    val typeUrl: String,
    val value: ByteString = ByteString.EMPTY
    ) : Message(ADAPTER, ByteString.EMPTY) {
    fun unpack(adapter: ProtoAdapter): T
    fun unpackOrNull(adapter: ProtoAdapter): T?
    companion object {
    fun pack(message: Message<*, *>): AnyMessage
    }
    }
    

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21. val person: Person = anyMessage.unpack(Person.ADAPTER)
    val anyMessage: AnyMessage = AnyMessage.ADAPTER.pack(person)
    

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22. JSON
    

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23. JSON?
    

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24. Why JSON?
    

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25. JSON
    • Proto2 : Wire & Protoc communication is dangerous.
    • Proto3 : All good.
    

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26. Proto2 㲗 Proto3
    Compatibility
    

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27. Proto2 㲗 Proto3 Compatibility
    • Cannot reference proto2 enums in proto3 message.
    • Anything else is good.
    

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28. Goodies
    

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29. Goodies
    package proto.package;
    import "wire/extensions.proto";
    option java_package = "java.package";
    option (wire.wire_package) = "wire.package";
    message MyMessage {}
    

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30. WIRE & Proto3
    FIN
    

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31. References
    • Protocol Buffers documentations
    • https://developers.google.com/protocol-buffers/
    • Wire documentations
    • https://square.github.io/wire/
    

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