Interface Configuration

The base URL against which the relative URIs are resolved, i.e. Configuration#workerURI, Configuration#wasmURI and CodecDefinition#codecURI.

The size of the chunks in bytes during data compression/decompression.

Values lower than 64 are raised to 64, and a value that is not an integer greater than 0 is replaced with the default value.

The stream implementation used to compress data when useCompressionStream is set to true.

The stream implementation used to compress data when useCompressionStream is set to false.

The function used to create the web workers, taking precedence over workerURI.

It lets bundlers detect the worker script statically and compile it with its imports, e.g. a custom worker script embedding alternative compression streams.

Here is an example with a custom worker script (see initWorker for the content of the script):

configure({
  createWorker: () => new Worker(new URL("./zip-worker.js", import.meta.url), { type: "module" })
});
Copy

It is also the way to run the web workers on engines where TransformStream is missing from the scope of the workers, e.g. Firefox before version 102. There, the worker script of zip.js throws when it is evaluated and the data is silently compressed/decompressed in the main scope instead. A polyfill imported by the page does not help, because the worker reads the globals of the Streams API from its own scope, so it has to be installed by the worker itself before the worker script of zip.js runs. These engines predate the support of module workers, hence the classic worker script below:

// zip-worker-with-polyfill.js
importScripts("./web-streams-polyfill.js", "./zip-web-worker.js");
Copy

configure({
  createWorker: () => new Worker("./zip-worker-with-polyfill.js")
});
Copy

The stream implementation used to decompress data when useCompressionStream is set to true.

The stream implementation used to decompress data when useCompressionStream is set to false.

The maximum number of web workers used to compress/decompress data simultaneously.

It must be an integer greater than 0, see ERR_INVALID_MAX_WORKERS.

The delay in milliseconds before idle web workers are automatically terminated. You can call terminateWorkers() to terminate idle workers.

The URI of the WebAssembly module used by default implementations to compress/decompress data. It is ignored if useCompressionStream is set to true and CompressionStream/DecompressionStream are supported by the environment.

Here is an example to import the WASM module as a URL (see ?url) and avoid CSP issues:

import wasmURI from "@zip.js/zip.js/dist/zip-module.wasm?url";

configure({
  wasmURI
});
Copy

The delay in milliseconds before a newly created web worker which has not sent any message is considered dead, terminated, and replaced with inline processing.

It allows recovering from environments where web workers fail silently, e.g. extension pages blocking worker scripts via their Content Security Policy.

The delay in milliseconds after which the oldest pending compression/decompression task is run without a web worker when no task completes.

It prevents deadlocks when entries read from a ZipReader are added concurrently into a ZipWriter and all the web workers are waiting for data.

The URI of the web worker.

It allows using alternative deflate implementations or specifying a URL to the worker script if the CSP of the page blocks scripts imported from a Data URI.

Here is an example to import the worker module as a URL (see ?url) and avoid CSP issues:

import workerURI from "@zip.js/zip.js/dist/zip-web-worker.js?url";

configure({
  workerURI
});
Copy

The worker is created as a module worker, unless the URI is a Data URI or a Blob URI, in which case it is created as a classic worker. See Configuration#createWorker for an example of classic worker script installing a polyfill of the Streams API.