r2-utils-js
Version:
Readium 2 'utils' for NodeJS (TypeScript)
87 lines • 2.92 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.HttpReadableStream = void 0;
const debug_ = require("debug");
const request = require("request");
const requestPromise = require("request-promise-native");
const stream_1 = require("stream");
const BufferUtils_1 = require("../stream/BufferUtils");
const debug = debug_("r2:utils#http/HttpReadableStream");
class HttpReadableStream extends stream_1.Readable {
constructor(url, byteLength, byteStart, byteEnd) {
super();
this.url = url;
this.byteLength = byteLength;
this.byteStart = byteStart;
this.byteEnd = byteEnd;
this.alreadyRead = 0;
}
_read(_size) {
const length = this.byteEnd - this.byteStart;
if (this.alreadyRead >= length) {
this.push(null);
return;
}
const failure = (err) => {
debug(err);
this.push(null);
};
const success = async (res) => {
if (res.statusCode && (res.statusCode < 200 || res.statusCode >= 300)) {
failure("HTTP CODE " + res.statusCode);
return;
}
let buffer;
try {
buffer = await (0, BufferUtils_1.streamToBufferPromise)(res);
}
catch (err) {
failure(err);
return;
}
this.alreadyRead += buffer.length;
this.push(buffer);
};
debug(`HTTP GET ${this.url}: ${this.byteStart}-${this.byteEnd} (${this.byteEnd - this.byteStart})`);
const lastByteIndex = this.byteEnd - 1;
const range = `${this.byteStart}-${lastByteIndex}`;
const needsStreamingResponse = true;
if (needsStreamingResponse) {
request.get({
headers: { Range: `bytes=${range}` },
method: "GET",
uri: this.url,
})
.on("response", async (res) => {
try {
await success(res);
}
catch (successError) {
failure(successError);
return;
}
})
.on("error", failure);
}
else {
(async () => {
let res;
try {
res = await requestPromise({
headers: { Range: `bytes=${range}` },
method: "GET",
resolveWithFullResponse: true,
uri: this.url,
});
}
catch (err) {
failure(err);
return;
}
await success(res);
})();
}
}
}
exports.HttpReadableStream = HttpReadableStream;
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