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send-ranges
Express middleware for handling HTTP range requests. Requires node 18 or higher.
Installation
npm install --save send-rangesUsage
const path = require('path')
const fse = require('fs-extra')
const express = require('express')
const sendRanges = require('send-ranges')
const app = express()
const mp3Path = path.join(__dirname, 'mp3s')
async function retrieveFile(request) {
const filename = request.params.filename
if (!/\.mp3$/.test(filename)) {
return null // Falsey values will call the next handler in line
}
const filePath = path.join(mp3Path, filename)
const getStream = (range) => fs.createReadStream(filePath, range)
const type = 'audio/mpeg'
const stats = await fse.stat(filePath)
return {getStream, type, size: stats.size}
}
app.get('/:filename', sendRanges(retrieveFile), (req, res) => {
// If we got here, this was not a range request, or the `retrieveFile` handler
// returned a falsey value
res.sendFile(path.join(mp3Path, req.params.filename))
})
app.listen(3000, () => {
console.log('Example app listening on port 3000!')
})Options
Exported function accept an options config object that will be passed to
range-parser. In addition that, this options object accept some
send-ranges specific ones:
Pre-send hook
You can pass a beforeSend function as an option. This is handy if you want to:
- Handle the response sending yourself
- Use metadata fetched in the file retriever to set headers on the response
- Validate and possibly cancel the response before it is sent
The retrieveFile function can return an additional metadata property which will be passed to the
beforeSend function. Here's an example:
async function retrieveFile(request) {
const file = await someObjectStore.getFile(request.path)
const size = file.size
const metadata = file.metadata
const type = metadata.contentType
const getStream = (range) => file.createReadStream(range)
return {getStream, size, metadata, type}
}
async function beforeSend(info, cb) {
const {request, response, metadata, sourceStream} = info
response.set('Last-Modified', new Date(metadata.updated).toUTCString())
cb()
}
app.get('/*', sendRanges(retrieveFile, {beforeSend}))Maximum number of ranges
By default, up to two ranges are allowed. The limit can be adjusted with the maxRanges option:
sendRanges(retrieveFile, {maxRanges: 4})intersectRanges
Optional function that allow to modify the list of ranges to be returned. This
can be used for example if the data is not fully available because your file has
holes in it. It will be called with an object with the same metadata field
used for the beforeSend() optional function, and a ranges field with the
list of ranges.
License
MIT © Espen Hovlandsdal