initial import

.gitattributes

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+* text=auto

.github/workflows/build.yml

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+name: build
+
+on: push
+
+jobs:
+  build:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Install Emscripten
+        uses: mymindstorm/setup-emsdk@v6
+        with:
+          # 1.39.{19,20} hit a bug in clang: https://bugs.llvm.org/show_bug.cgi?id=46786
+          version: 1.39.18
+      - name: Verify
+        run: emcc -v
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: make
+        run: make
+      - uses: actions/upload-artifact@v2
+        with:
+          name: dist
+          path: dist/

.gitignore

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+/dist/

.gitmodules

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+[submodule "zstd"]
+	path = zstd
+	url = https://github.com/facebook/zstd.git

LICENSE

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+MIT License
+
+Copyright (c) Kristian Klausen
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

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+CC := emcc
+CFLAGS = -O3 \
+	-s WASM=1 \
+	-s EXPORTED_FUNCTIONS="['_ZSTD_compress','_ZSTD_compressBound','_ZSTD_getFrameContentSize','_ZSTD_decompress','_ZSTD_isError','_ZSTD_getErrorName','_malloc','_free']" \
+	-s EXTRA_EXPORTED_RUNTIME_METHODS="['cwrap','stringToUTF8','UTF8ToString','lengthBytesUTF8']" \
+	-s ALLOW_MEMORY_GROWTH=1 \
+	-s MODULARIZE=1 \
+	-s EXPORT_NAME="'ZSTD'" \
+	--pre-js pre.js
+
+build:
+	cd zstd && CC=gcc emmake make lib-release
+	exit
+	mkdir -p dist
+	$(CC) $(CFLAGS) "zstd/lib/libzstd.so" -o "dist/zstd.js"
+
+clean:
+	rm -rf dist/

README.md

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+*This is mostly a POC and isn't used in production, you have been warned!*
+
+[`zstd`](https://github.com/facebook/zstd/) in the browser, because why not? ;)
+
+## Build
+```
+$ git clone --recurse-submodules https://github.com/klausenbusk/zstd.js.git
+$ cd zstd.js
+$ make
+```
+
+## Usage
+```javascript
+const zstd = await ZSTD();
+
+zstd.compress(<Uint8Array>, <compressionLevel>) <Uint8Array>
+zstd.decompress(<Uint8Array>) <Uint8Array>
+zstd.compressString(<string>) <Uint8Array>
+zstd.decompressString(<Uint8Array>) <string>
+```
+See also: [example.html](./example.html)

example.html

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+<script type="text/javascript" src="dist/zstd.js"></script>
+<script>
+	let zstd;
+	ZSTD().then(instance => {
+		zstd = instance;
+		test();
+	});
+
+	function test() {
+		let buffer = zstd.compressString("Hello World");
+		console.log(buffer);
+		console.log(zstd.decompressString(buffer.buffer));
+	}
+</script>

pre.js

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+let ZSTD_compressBound,ZSTD_compress,ZSTD_getFrameContentSize,ZSTD_decompress,ZSTD_isError,ZSTD_getErrorName;
+
+Module.preRun = function() {
+	ZSTD_compressBound = cwrap("ZSTD_compressBound", "number", ["number"]);
+	ZSTD_compress = cwrap("ZSTD_compress", "number", ["number", "number", "number", "number", "number"]);
+	ZSTD_getFrameContentSize = cwrap("ZSTD_getFrameContentSize", "number", ["number", "number"]);
+	ZSTD_decompress = cwrap("ZSTD_decompress", "number", ["number", "number", "number", "number"]);
+	ZSTD_isError = cwrap("ZSTD_isError", "number", ["number"]);
+	ZSTD_getErrorName = cwrap("ZSTD_getErrorName", "string", ["number"]);
+};
+
+function copy(src) {
+	return new Uint8Array(src);
+}
+
+// https://github.com/facebook/zstd/blob/15c5e200235edc520c1bd678ed126a6dd05736e1/examples/simple_compression.c#L17
+function compress(iSize, iBuff, compressionLevel) {
+	let cBuffSize = ZSTD_compressBound(iSize);
+	let cBuff = _malloc(cBuffSize);
+
+	let cSize = ZSTD_compress(cBuff, cBuffSize, iBuff, iSize, compressionLevel);
+	if (ZSTD_isError(cSize)) {
+		_free(iBuff);
+		_free(cBuff);
+		throw new Error(ZSTD_getErrorName(cSize));
+	}
+
+	let cData = new Uint8Array(HEAPU8.buffer, cBuff, cSize);
+	cData = copy(cData);
+
+	_free(iBuff);
+	_free(cBuff);
+
+	return cData;
+};
+
+Module.compress = function(input, compressionLevel = 3) {
+	if (!(input instanceof Uint8Array)) {
+		throw new TypeError();
+	}
+
+	let iSize = input.byteLength;
+	let iBuff = _malloc(iSize);
+	HEAPU8.set(new Uint8Array(input), iBuff);
+
+	return compress(iSize, iBuff, compressionLevel);
+};
+
+Module.compressString = function(input, compressionLevel) {
+	// https://stackoverflow.com/a/203757
+	if (typeof input !== "string") {
+		throw new TypeError();
+	}
+
+	let iSize = lengthBytesUTF8(input)+1;
+	let iBuff = _malloc(iSize);
+	stringToUTF8(input, iBuff, iSize);
+
+	return compress(iSize, iBuff, compressionLevel);
+};
+
+// https://github.com/facebook/zstd/blob/15c5e200235edc520c1bd678ed126a6dd05736e1/examples/simple_decompression.c#L16
+function decompress(input) {
+	if (!(input instanceof Uint8Array)) {
+		throw new TypeError();
+	}
+
+	let cSize = input.byteLength;
+	let cBuff = _malloc(cSize);
+	HEAPU8.set(new Uint8Array(input), cBuff);
+
+	rSize = ZSTD_getFrameContentSize(cBuff, cSize);
+	if (rSize < 0) {
+		_free(cBuff);
+		throw new Error(rSize);
+	}
+
+	let rBuff = _malloc(rSize);
+	let dSize = ZSTD_decompress(rBuff, rSize, cBuff, cSize);
+	if (ZSTD_isError(dSize)) {
+		_free(cBuff);
+		_free(rBuff);
+		throw new Error(ZSTD_getErrorName(cSize));
+	}
+	_free(cBuff);
+
+	return [rBuff, dSize];
+};
+
+Module.decompress = function(input) {
+	[rBuff, dSize] = decompress(input);
+
+	let cData = new Uint8Array(HEAPU8.buffer, rBuff, dSize);
+	cData = copy(cData);
+	_free(rBuff);
+
+	return cData;
+};
+
+Module.decompressString = function(input) {
+	[rBuff, dSize] = decompress(input);
+
+	let s = UTF8ToString(rBuff, dSize);
+	_free(rBuff);
+
+	return s;
+};