presto.js is a small JavaScript library for splitting and transferring files
The basic idea is to split files into small chunks, send them simultaneously and rebuild them into files again on the server side.
File data is cut out in chunks of 1MB each and sent in parallel to achieve a faster transfer rate than the standard function. The chunk size and number of parallel transfers can be changed by the user.
Faster
Faster than web browsers' default file transfer implementation.
Easy to integrate
Works without dependent libraries on all modern browsers. See minimal example below!
Effective for transferring huge size files
You can upload hundreds of GB of files at a time with presto.
Save memory
presto.js doesn't suppress computer memory even if the user sends hundreds of GB files for hours..
See the Pen presto.js minimal example by Yu Watanabe (@yuw27b) on CodePen.
const presto = new Presto({ url: '/api/upload', ... });url: [string] URL of upload destination. (Default: '')chunkSize: [integer] Size (byte) of each chunk (Default: 1048576 //1MB)simultaneous: [integer] Number of chunks to send abreast. 6 is recommended for HTTP/1.1 and 10 is recommended for HTTP/2. (Default: 6)element: [HTMLFormElement] If specified, the upload will start automatically when the form is submitted. The element must have a HTMLFormInput[type="file"] as a child. (Default: null)uniqueIdGenerator: [function] A custom function that defines a unique ID for each file. The ID is sent with each chunk. (Default: fileObject => {return `presto_${UUID_V4_STRING}`; })httpHeaders: [function] A custom function to add HTTP headers to each chunk send request. (Default: PrestoFile => {return {}; })withCredentials: [boolean] This value is used as the withCredentials option of the chunk send request(XMLHttpRequest). Set true to send cookies with cross domain request. (Default: false)Presto.fileList: [array] Array of PrestoFile.PrestoFile.prestoId: [string] Unique ID of PrestoFile.PrestoFile.name: [string] File name.PrestoFile.size: [integer] File size (byte).PrestoFile.displaySize: [string] Human readable file size.Presto.on(string eventName, function callback): Add event listener to Presto.Presto.off(string eventName, function callback): Remove event listener from Presto.Presto.add(HTML5 FileList object, object optional form data): Add file(s) to Presto.Presto.remove(string prestoId): Remove file from Presto. If nothing is specified, remove all files.Presto.reset(HTML5 FileList object, object optional form data): Replace Presto.fileList with specified file list. If nothing is specified, remove all files.Presto.send(string prestoId): Start file upload of the specified file. If nothing is specified, upload all files.Presto.abort(string prestoId): Abort file upload of the specified file. If nothing is specified, abort all files.Presto.progress(string prestoId): Return upload progress (float number between 0 - 1) of the specified file. If nothing is specified, return progress for all files.Presto offers the following events:
added: Fires when file is added. Returns array of PrestoFile.removed: Fires when file(s) is removed. Returns array of removed file ID.reset: Fires when Presto.fileList is reset.start: Fires when uploading is started.abort: Fires when uploading is aborted.complete: Fires when uploading is completed. Returns duration of uploading(msec).progress: Fires whenever chunk upload succeeds. Returns progress for all files(float number between 0 - 1).fileStart: Fires whenever uploading of each file is started. Returns PrestoFile.fileAbort: Fires whenever uploading of each file is aborted. Returns PrestoFile.fileComplete: Fires whenever uploading of each file is completed. Returns PrestoFile.fileProgress: Fires whenever chunk upload succeeds. Returns fileProgress(float number between 0 - 1), PrestoFile.fileError: Fires when chunk upload fails. Returns chunkIndex, HTTP status code, HTTP status text, PrestoFile.PrestoFile offers the following events:
start: Fires when upload started. Returns PrestoFile.abort: Fires when upload aborted. Returns PrestoFile.complete: Fires when upload completed. Returns PrestoFile.progress: Fires whenever chunk upload succeed. Returns fileProgress(float number between 0 - 1), PrestoFile.error: Fires when chunk upload failed. Returns chunkIndex, XMLHttpRequest.status, XMLHttpRequest.statusText, PrestoFile.