76 lines
2.0 KiB
JavaScript
76 lines
2.0 KiB
JavaScript
const fetch = require('node-fetch');
|
|
const fs = require('fs');
|
|
const crypto = require('crypto');
|
|
const path = require('path');
|
|
|
|
function md5(str) {
|
|
return crypto.createHash('md5').update(str).digest('hex');
|
|
}
|
|
|
|
async function getResponse(cacheDirPath, requestArguments, bodyFunctionName) {
|
|
const [url, requestInit, ...rest] = requestArguments;
|
|
const requestParams = requestInit && requestInit.body
|
|
? ({ ...requestInit, body: typeof requestInit.body === 'object' ? requestInit.body.toString() : requestInit.body })
|
|
: requestInit;
|
|
|
|
const cacheHash = md5(JSON.stringify([url, requestParams, ...rest]) + bodyFunctionName);
|
|
const cachedFilePath = path.join(cacheDirPath, `${cacheHash}.json`);
|
|
|
|
try {
|
|
const body = JSON.parse(await fs.promises.readFile(cachedFilePath));
|
|
if (bodyFunctionName === 'buffer') {
|
|
return Buffer.from(body);
|
|
}
|
|
|
|
return body;
|
|
} catch (err) {
|
|
const fetchResponse = await fetch(...requestArguments);
|
|
const bodyResponse = await fetchResponse[bodyFunctionName]();
|
|
await fs.promises.writeFile(cachedFilePath, JSON.stringify(bodyResponse));
|
|
return bodyResponse;
|
|
}
|
|
}
|
|
|
|
class ResponseWrapper {
|
|
constructor(cacheDirPath, requestArguments) {
|
|
this.cacheDirPath = cacheDirPath;
|
|
this.requestArguments = requestArguments;
|
|
}
|
|
|
|
text() {
|
|
return getResponse(this.cacheDirPath, this.requestArguments, this.text.name);
|
|
}
|
|
|
|
json() {
|
|
return getResponse(this.cacheDirPath, this.requestArguments, this.json.name);
|
|
}
|
|
|
|
buffer() {
|
|
return getResponse(this.cacheDirPath, this.requestArguments, this.buffer.name);
|
|
}
|
|
|
|
textConverted() {
|
|
return getResponse(this.cacheDirPath, this.requestArguments, this.textConverted.name);
|
|
}
|
|
}
|
|
|
|
function createFetch(cacheDirPath) {
|
|
let madeDir = false;
|
|
|
|
return async (...args) => {
|
|
if (!madeDir) {
|
|
try {
|
|
await fs.promises.mkdir(cacheDirPath, { recursive: true });
|
|
} catch (err) {
|
|
// Ignore.
|
|
}
|
|
|
|
madeDir = true;
|
|
}
|
|
|
|
return new ResponseWrapper(cacheDirPath, args);
|
|
};
|
|
}
|
|
|
|
module.exports = createFetch;
|