otterscan/src/use4Bytes.ts

99 lines
2.6 KiB
TypeScript

import { useState, useEffect, useContext } from "react";
import { RuntimeContext } from "./useRuntime";
import { fourBytesURL } from "./url";
export type FourBytesEntry = {
name: string;
signature: string | undefined;
};
const simpleTransfer: FourBytesEntry = {
name: "Transfer",
signature: undefined,
};
const fullCache = new Map<string, FourBytesEntry | null>();
export const rawInputTo4Bytes = (rawInput: string) => rawInput.slice(0, 10);
/**
* Extract 4bytes DB info
*
* @param rawFourBytes an hex string containing the 4bytes signature in the "0xXXXXXXXX" format.
*/
export const use4Bytes = (
rawFourBytes: string
): FourBytesEntry | null | undefined => {
if (rawFourBytes !== "0x") {
if (rawFourBytes.length !== 10 || !rawFourBytes.startsWith("0x")) {
throw new Error(
`rawFourBytes must contain a 4 bytes hex method signature starting with 0x; received value: "${rawFourBytes}"`
);
}
}
const runtime = useContext(RuntimeContext);
const assetsURLPrefix = runtime.config?.assetsURLPrefix;
const fourBytes = rawFourBytes.slice(2);
const [entry, setEntry] = useState<FourBytesEntry | null | undefined>(
fullCache.get(fourBytes)
);
useEffect(() => {
if (assetsURLPrefix === undefined) {
return;
}
if (fourBytes === "") {
return;
}
const signatureURL = fourBytesURL(assetsURLPrefix, fourBytes);
fetch(signatureURL)
.then(async (res) => {
if (!res.ok) {
console.error(`Signature does not exist in 4bytes DB: ${fourBytes}`);
fullCache.set(fourBytes, null);
setEntry(null);
return;
}
// Get only the first occurrence, for now ignore alternative param names
const sigs = await res.text();
const sig = sigs.split(";")[0];
const cut = sig.indexOf("(");
let method = sig.slice(0, cut);
method = method.charAt(0).toUpperCase() + method.slice(1);
const entry: FourBytesEntry = {
name: method,
signature: sig,
};
setEntry(entry);
fullCache.set(fourBytes, entry);
})
.catch((err) => {
console.error(`Couldn't fetch signature URL ${signatureURL}`, err);
setEntry(null);
fullCache.set(fourBytes, null);
});
}, [fourBytes, assetsURLPrefix]);
if (rawFourBytes === "0x") {
return simpleTransfer;
}
if (assetsURLPrefix === undefined) {
return undefined;
}
// Try to resolve 4bytes name
if (entry === null || entry === undefined) {
return entry;
}
// Simulates LRU
// TODO: implement LRU purging
fullCache.delete(fourBytes);
fullCache.set(fourBytes, entry);
return entry;
};