Writing a Resolver

编写解析器

Resolvers are specified in EIP137. A resolver must implement the following method: EIP137中描述了解析器的详细信息。一个解析器必须实现以下方法:

function supportsInterface(bytes4 interfaceID) constant returns (bool);
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supportsInterface is defined in EIP165, and allows callers to determine if a resolver supports a particular record type. Record types are specified as a set of one or more methods that a resolver must implement together. Currently defined record types include: supportsInterfaceEIP165中定义,它可以被调用者用来确定一个解析器是否支持某个特定的记录类型。记录类型是指解析器必须一起实现的一个或多个方法的集合。当前定义的记录类型包括:

Record type Function(s) Interface ID Defined in
Ethereum address addr 0x3b3b57de EIP137
ENS Name name 0x691f3431 EIP181
ABI specification ABI 0x2203ab56 EIP205
Public key pubkey 0xc8690233 EIP619
Text records text 0x59d1d43c EIP634
Content hash contenthash 0xbc1c58d1
记录类型 函数 接口ID 定义文档
:--- :--- :--- :---
以太坊地址 addr 0x3b3b57de EIP137
ENS域名 name 0x691f3431 EIP181
ABI规范 ABI 0x2203ab56 EIP205
公钥 pubkey 0xc8690233 EIP619
文本记录 text 0x59d1d43c EIP634
内容散列 contenthash 0xbc1c58d1

supportsInterface must also return true for the interfaceID value 0x01ffc9a7, which is the interface ID of supportsInterface itself. supportsInterface本身的接口ID为0x01ffc9a7,当interfaceID值为0x01ffc9a7时,supportsInterface也必须返回true。

Additionally, the content interface was used as a defacto standard for Swarm hashes, and has an interface ID of 0xd8389dc5. New implementations should use contenthash instead. 此外,content接口被用作Swarm散列事实上的标准,它的接口ID为0xd8389dc5。现在新的内容散列应该使用contenthash接口来实现。

Example Resolver

解析器示例

A simple resolver that supports only the addr type might look something like this: 一个只支持addr类型的简易解析器,看起来就像这样:

contract SimpleResolver {
    function supportsInterface(bytes4 interfaceID) constant returns (bool) {
        return interfaceID == 0x3b3b57de;
    }

    function addr(bytes32 nodeID) constant returns (address) {
        return address(this);
    }
}
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这个简易解析器总是返回自己的地址作为所有查询的结果。尽管解析器采用不同的机制应该返回相同的结果,但实际上解析器可以按照需要采用任何机制来确定返回的结果,并且应该尽可能降低gas费用。

Last Updated: 10/30/2019, 7:54:43 PM