Merge pull request #15 from willfarrell/feature/stream-example

Docs: add in stream example

Author: pimterry

README.md

@@ -29,33 +29,103 @@ For advanced use data-streaming use cases, `CompressStream` and `DecompressStrea
 
 ### Usage
 
-In node.js:
+If you want to support node & browsers with the same code, you can use the `await` browser-compatible form with the default export everywhere.
+
+#### In node.js:
 
 ```javascript
-const * as brotli = require('brotli-wasm');
+const brotli = require('brotli-wasm');
 
 const compressedData = brotli.compress(Buffer.from('some input'));
 const decompressedData = brotli.decompress(compressedData);
 
 console.log(Buffer.from(decompressedData).toString('utf8')); // Prints 'some input'
 ```
 
-In browsers:
+#### In browsers:
 
 ```javascript
 import brotliPromise from 'brotli-wasm'; // Import the default export
 
 const brotli = await brotliPromise; // Import is async in browsers due to wasm requirements!
 
-const compressedData = brotli.compress(Buffer.from('some input'));
+const textEncoder = new TextEncoder();
+const textDecoder = new TextDecoder();
+
+const input = 'some input';
+
+const uncompressedData = textEncoder.encode('some input');
+const compressedData = brotli.compress(uncompressedData);
 const decompressedData = brotli.decompress(compressedData);
 
-console.log(Buffer.from(decompressedData).toString('utf8')); // Prints 'some input'
+console.log(textDecoder.decode(decompressedData)); // Prints 'some input'
 ```
 
-The package itself has no runtime dependencies, but you will need a [browser Buffer polyfill](https://www.npmjs.com/package/browserify-zlib) for the above example code, or you can do the same using TextEncoder/Decoder instead if you prefer.
+The package itself has no runtime dependencies, although if you prefer using `Buffer` over using `TextEncoder/TextDecoder` you may want a [browser Buffer polyfill](https://www.npmjs.com/package/browserify-zlib).
+
+#### In browser with streams:
+
+```javascript
+import brotliPromise from 'brotli-wasm'; // Import the default export
+
+const brotli = await brotliPromise; // Import is async in browsers due to wasm requirements!
+
+const input = 'some input';
+
+const inputStream = new ReadableStream({
+    start (controller) {
+        controller.enqueue(input);
+        controller.close();
+    }
+});
+
+const textEncoderStream = new TextEncoderStream();
+const compressStream = new brotli.CompressStream();
+const compressionStream = new TransformStream({
+    start () {},
+    transform (chunk, controller) {
+        controller.enqueue(compressStream.compress(chunk, 100));
+    },
+    flush (controller) {
+        if (compressStream.result() === brotli.BrotliStreamResult.NeedsMoreInput) {
+            controller.enqueue(compressStream.compress(undefined, 100));
+        }
+        controller.terminate();
+    }
+});
+
+const decompressStream = new brotli.DecompressStream();
+const decompressionStream = new TransformStream({
+    start () {},
+    transform (chunk, controller) {
+        controller.enqueue(decompressStream.decompress(chunk, 100));
+    },
+    flush (controller) {
+        if (decompressStream.result() === brotli.BrotliStreamResult.NeedsMoreInput) {
+            controller.enqueue(decompressStream.decompress(undefined, 100));
+        }
+        controller.terminate();
+    }
+});
+
+const textDecoderStream = new TextDecoderStream()
+const outputStream = new WritableStream({
+    write (chunk) {
+        output += chunk;
+    }
+});
+
+let output = '';
+await inputStream
+    .pipeThrough(textEncoderStream)
+    .pipeThrough(compressionStream)
+    .pipeThrough(decompressionStream)
+    .pipeThrough(textDecoderStream)
+    .pipeTo(outputStream);
+console.log(output); // Prints 'some input'
+```
 
-If you want to support node & browsers with the same code, you can use the `await` form with the default export everywhere.
+Note that `TransformStream` has become available in all browsers as of mid-2022. https://caniuse.com/mdn-api_transformstream
 
 ## Alternatives