Add Wasm compression

js/utils/base64DecToArr.js

@@ -0,0 +1,46 @@
+function base64DecToArr (sBase64) {
+/*\
+|*|
+|*|  Base64 / binary data / UTF-8 strings utilities
+|*|
+|*|  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Base64_encoding_and_decoding
+|*|
+\*/
+
+/* Array of bytes to Base64 string decoding */
+
+function b64ToUint6 (nChr) {
+
+  return nChr > 64 && nChr < 91 ?
+      nChr - 65
+    : nChr > 96 && nChr < 123 ?
+      nChr - 71
+    : nChr > 47 && nChr < 58 ?
+      nChr + 4
+    : nChr === 43 ?
+      62
+    : nChr === 47 ?
+      63
+    :
+      0;
+
+}
+
+  var
+    nInLen = sBase64.length,
+    nOutLen = nInLen * 3 + 1 >> 2, taBytes = new Uint8Array(nOutLen);
+
+  for (var nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {
+    nMod4 = nInIdx & 3;
+    nUint24 |= b64ToUint6(sBase64.charCodeAt(nInIdx)) << 6 * (3 - nMod4);
+    if (nMod4 === 3 || nInLen - nInIdx === 1) {
+      for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {
+        taBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;
+      }
+      nUint24 = 0;
+
+    }
+  }
+
+  return taBytes;
+}

js/utils/mini-lz4.js

@@ -0,0 +1,116 @@
+function uncompress(source, uncompressedSize) {
+/*
+based off https://github.com/emscripten-core/emscripten/blob/main/third_party/mini-lz4.js
+The license only applies to the body of this function (``uncompress``).
+====
+MiniLZ4: Minimal LZ4 block decoding and encoding.
+
+based off of node-lz4, https://github.com/pierrec/node-lz4
+
+====
+Copyright (c) 2012 Pierre Curto
+
+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.
+====
+
+changes have the same license
+*/
+/**
+ * Decode a block. Assumptions: input contains all sequences of a
+ * chunk, output is large enough to receive the decoded data.
+ * If the output buffer is too small, an error will be thrown.
+ * If the returned value is negative, an error occurred at the returned offset.
+ *
+ * @param {ArrayBufferView} input input data
+ * @param {ArrayBufferView} output output data
+ * @param {number=} sIdx
+ * @param {number=} eIdx
+ * @return {number} number of decoded bytes
+ * @private
+ */
+function uncompressBlock (input, output, sIdx, eIdx) {
+	sIdx = sIdx || 0
+	eIdx = eIdx || (input.length - sIdx)
+	// Process each sequence in the incoming data
+	for (var i = sIdx, n = eIdx, j = 0; i < n;) {
+		var token = input[i++]
+
+		// Literals
+		var literals_length = (token >> 4)
+		if (literals_length > 0) {
+			// length of literals
+			var l = literals_length + 240
+			while (l === 255) {
+				l = input[i++]
+				literals_length += l
+			}
+
+			// Copy the literals
+			var end = i + literals_length
+			while (i < end) output[j++] = input[i++]
+
+			// End of buffer?
+			if (i === n) return j
+		}
+
+		// Match copy
+		// 2 bytes offset (little endian)
+		var offset = input[i++] | (input[i++] << 8)
+
+		// XXX 0 is an invalid offset value
+		if (offset === 0) return j
+		if (offset > j) return -(i-2)
+
+		// length of match copy
+		var match_length = (token & 0xf)
+		var l = match_length + 240
+		while (l === 255) {
+			l = input[i++]
+			match_length += l
+		}
+		// Copy the match
+		var pos = j - offset // position of the match copy in the current output
+		var end = j + match_length + 4 // minmatch = 4
+		while (j < end) output[j++] = output[pos++]
+	}
+
+	return j
+}
+var result = new ArrayBuffer(uncompressedSize);
+var sourceIndex = 0;
+var destIndex = 0;
+var blockSize;
+while((blockSize = (source[sourceIndex] | (source[sourceIndex + 1] << 8) | (source[sourceIndex + 2] << 16) | (source[sourceIndex + 3] << 24))) > 0)
+{
+	sourceIndex += 4;
+	if (blockSize & 0x80000000)
+	{
+		blockSize &= 0x7FFFFFFFF;
+		for (var i = 0; i < blockSize; i++) {
+			result[destIndex++] = source[sourceIndex++];
+		}
+	}
+	else
+	{
+		destIndex += uncompressBlock(source, new Uint8Array(result, destIndex, uncompressedSize - destIndex), sourceIndex, sourceIndex + blockSize);
+		sourceIndex += blockSize;
+	}
+}
+return new Uint8Array(result, 0, uncompressedSize);
+}