crc-32 - npm Package Compare versions

Comparing version 0.1.0 to 0.2.0

bits/01_version.js

@@ -1,1 +0,1 @@
-CRC32.version = '0.1.0';
+CRC32.version = '0.2.0';

bits/20_crctable.js

@@ -18,5 +18,5 @@ /* see perf/crc32table.js */
 
-	return table;
+	return typeof Int32Array !== 'undefined' ? new Int32Array(table) : table;
 }
 
 var table = signed_crc_table();

bits/40_crc.js

 /* charCodeAt is the best approach for binary strings */
+var use_buffer = typeof Buffer !== 'undefined';
 function crc32_bstr(bstr) {
-	for(var crc = -1, i = 0, L=bstr.length-1; i < L;) {
-		crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
-		crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
+	if(bstr.length > 32768) if(use_buffer) return crc32_buf(Buffer(bstr));
+	var crc = -1, L = bstr.length - 1;
+	for(var i = 0; i < L;) {
+		crc =  table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8);
+		crc =  table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8);
 	}
-	if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
+	if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i)) & 0xFF];
 	return crc ^ -1;
@@ -12,5 +15,14 @@ }
 function crc32_buf(buf) {
-	for(var crc = -1, i = 0; i != buf.length; ++i) {
-		crc = (crc >>> 8) ^ table[(crc ^ buf[i]) & 0xFF];
+	for(var crc = -1, i = 0, L=buf.length-3; i < L;) {
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
 	}
+	if(i < L+3) {
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		if(i < L+3) {
+			crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+			if(i < L+3) {
+				crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; }}}
 	return crc ^ -1;
@@ -17,0 +29,0 @@ }

crc32.js

@@ -5,3 +5,3 @@ /* crc32.js (C) 2014 SheetJS -- http://sheetjs.com */
 (function(CRC32) {
-CRC32.version = '0.1.0';
+CRC32.version = '0.2.0';
 /* see perf/crc32table.js */
@@ -24,3 +24,3 @@ function signed_crc_table() {
 
-	return table;
+	return typeof Int32Array !== 'undefined' ? new Int32Array(table) : table;
 }
@@ -30,8 +30,11 @@
 /* charCodeAt is the best approach for binary strings */
+var use_buffer = typeof Buffer !== 'undefined';
 function crc32_bstr(bstr) {
-	for(var crc = -1, i = 0, L=bstr.length-1; i < L;) {
-		crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
-		crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
+	if(bstr.length > 32768) if(use_buffer) return crc32_buf(Buffer(bstr));
+	var crc = -1, L = bstr.length - 1;
+	for(var i = 0; i < L;) {
+		crc =  table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8);
+		crc =  table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8);
 	}
-	if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
+	if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i)) & 0xFF];
 	return crc ^ -1;
@@ -41,5 +44,14 @@ }
 function crc32_buf(buf) {
-	for(var crc = -1, i = 0; i != buf.length; ++i) {
-		crc = (crc >>> 8) ^ table[(crc ^ buf[i]) & 0xFF];
+	for(var crc = -1, i = 0, L=buf.length-3; i < L;) {
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
 	}
+	if(i < L+3) {
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		if(i < L+3) {
+			crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+			if(i < L+3) {
+				crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; }}}
 	return crc ^ -1;
@@ -46,0 +58,0 @@ }

ctest/crc32.js

@@ -5,3 +5,3 @@ /* crc32.js (C) 2014 SheetJS -- http://sheetjs.com */
 (function(CRC32) {
-CRC32.version = '0.1.0';
+CRC32.version = '0.2.0';
 /* see perf/crc32table.js */
@@ -24,3 +24,3 @@ function signed_crc_table() {
 
-	return table;
+	return typeof Int32Array !== 'undefined' ? new Int32Array(table) : table;
 }
@@ -30,8 +30,11 @@
 /* charCodeAt is the best approach for binary strings */
+var use_buffer = typeof Buffer !== 'undefined';
 function crc32_bstr(bstr) {
-	for(var crc = -1, i = 0, L=bstr.length-1; i < L;) {
-		crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
-		crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
+	if(bstr.length > 32768) if(use_buffer) return crc32_buf(Buffer(bstr));
+	var crc = -1, L = bstr.length - 1;
+	for(var i = 0; i < L;) {
+		crc =  table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8);
+		crc =  table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8);
 	}
-	if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i++)) & 0xFF];
+	if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i)) & 0xFF];
 	return crc ^ -1;
@@ -41,5 +44,14 @@ }
 function crc32_buf(buf) {
-	for(var crc = -1, i = 0; i != buf.length; ++i) {
-		crc = (crc >>> 8) ^ table[(crc ^ buf[i]) & 0xFF];
+	for(var crc = -1, i = 0, L=buf.length-3; i < L;) {
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
 	}
+	if(i < L+3) {
+		crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+		if(i < L+3) {
+			crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF];
+			if(i < L+3) {
+				crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; }}}
 	return crc ^ -1;
@@ -46,0 +58,0 @@ }

ctest/fixtures.js

@@ -9,2 +9,94 @@ var bits = [
 if(typeof module !== "undefined") module.exports = bits;
+if(typeof require !== 'undefined') {
+var js_crc32 = require('../');
+var buffer_crc32 = require('./buffer-crc32');
+var crc32 = require('./crc32');
+var node_crc = require('./node-crc');
+
+function z1(bstr) { return js_crc32.bstr(bstr); }
+function z2(bstr) { return buffer_crc32.signed(bstr); }
+function z3(bstr) { return crc32(bstr); }
+function z4(bstr) { return node_crc.crc32(bstr);}
+
+function b1(buf) { return js_crc32.buf(buf); }
+function b2(buf) { return buffer_crc32.signed(buf); }
+function b3(buf) { return crc32(buf); }
+function b4(buf) { return node_crc.crc32(buf); }
+
+function u1(str) { return js_crc32.str(str); }
+function u2(str) { return buffer_crc32.signed(str); }
+
+var ntests, len_max;
+switch(process.env.MODE) {
+	case "A": ntests = 100000; len_max = 256; break;
+	case "B": ntests = 10000; len_max = 1024; break;
+	case "C": ntests = 10000; len_max = 4096; break;
+	case "D": ntests = 1000; len_max = 16384; break;
+	case "E": ntests = 1000; len_max = 65536; break;
+	case "F": ntests = 100; len_max = 262144; break;
+	default:  ntests = 10000; len_max = 1024; break;
+}
+
+var btest = true, utest = true;
+
+var bstr_tests = [];
+var ustr_tests = [];
+var len_min = 1;
+
+var corpus = new Array(0x0800);
+for(var k = 0; k < 0x0800; ++k) corpus[k] = String.fromCharCode(k)
+len_max --;
+
+k = (Math.random()*0x800)|0;
+for(var i = 0; i < ntests; ++i) {
+	var l = (Math.random() * (len_max - len_min))|0 + len_min;
+	var s = new Array(l), t = new Array(l);
+	if(btest) for(var j = 0; j < l; ++j) s[j] = corpus[(i+j+k)&127];
+	if(utest) for(var j = 0; j < l; ++j) t[j] = corpus[(i+j+k)&0x7FF];
+	var ss = s.join("");
+	bstr_tests[i] = [ss, new Buffer(ss)];
+	ustr_tests[i] = t.join("");
+}
+
+var assert = require('assert');
+function fix(str) { return parseInt(str, 16)|0; }
+if(btest) for(var j = 0; j != ntests; ++j) {
+	assert.equal(z1(bstr_tests[j][0]), b1(bstr_tests[j][1]));
+
+	assert.equal(z1(bstr_tests[j][0]), z2(bstr_tests[j][0]));
+	assert.equal(z1(bstr_tests[j][0]), fix(z3(bstr_tests[j][0])));
+	assert.equal(z1(bstr_tests[j][0]), fix(z4(bstr_tests[j][0])));
+
+	assert.equal(b1(bstr_tests[j][1]), b2(bstr_tests[j][1]));
+	assert.equal(b1(bstr_tests[j][1]), fix(b3(bstr_tests[j][1])));
+	assert.equal(b1(bstr_tests[j][1]), fix(b4(bstr_tests[j][1])));
+}
+if(utest) for(var j = 0; j != ntests; ++j) {
+	assert.equal(u1(ustr_tests[j]), u2(ustr_tests[j]));
+}
+
+var BM = require('../perf/bm');
+var suite = new BM('binary string (' + len_max + ')');
+suite.add('js-crc32', function() { for(var j = 0; j != ntests; ++j) z1(bstr_tests[j][0]); });
+suite.add('buffer-crc32', function() { for(var j = 0; j != ntests; ++j) z2(bstr_tests[j][0]); });
+if(len_max < 4096) {
+	suite.add('crc32', function() { for(var j = 0; j != ntests; ++j) z3(bstr_tests[j][0]); });
+	suite.add('node_crc', function() { for(var j = 0; j != ntests; ++j) z4(bstr_tests[j][0]); });
+}
+suite.run();
+
+suite = new BM('buffer (' + len_max + ')');
+suite.add('js-crc32', function() { for(var j = 0; j != ntests; ++j) b1(bstr_tests[j][1]); });
+suite.add('buffer-crc32', function() { for(var j = 0; j != ntests; ++j) b2(bstr_tests[j][1]); });
+if(len_max < 1024) {
+	suite.add('crc32', function() { for(var j = 0; j != ntests; ++j) b3(bstr_tests[j][1]); });
+	suite.add('node_crc', function() { for(var j = 0; j != ntests; ++j) b4(bstr_tests[j][1]); });
+}
+suite.run();
+
+var suite = new BM('unicode string (' + len_max + ')');
+suite.add('js-crc32', function() { for(var j = 0; j != ntests; ++j) u1(ustr_tests[j]); });
+suite.add('buffer-crc32', function() { for(var j = 0; j != ntests; ++j) u2(ustr_tests[j]); });
+suite.run();
+}
 crc32table = [
@@ -11,0 +103,0 @@ 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,

package.json

 {
 	"name": "crc-32",
-	"version": "0.1.0",
+	"version": "0.2.0",
 	"author": "sheetjs",
@@ -5,0 +5,0 @@ "description": "Pure-JS CRC-32",

perf/bm.js

@@ -1,2 +0,2 @@
-/* ssf.js (C) 2014 SheetJS -- http://sheetjs.com */
+/* bm.js (C) 2014 SheetJS -- http://sheetjs.com */
 var Benchmark = require('benchmark');
@@ -15,8 +15,14 @@ var c = require('ansi')(process.stdout);
 	this.suite = new Benchmark.Suite(name, { onComplete: suite_end });
+	this.suites = [];
+	this.maxlen = 0;
 }
 
-BM.prototype.run = function() { this.suite.run(); };
+BM.prototype.run = function() {
+	var maxlen = this.maxlen, ss = this.suite;
+	this.suites.forEach(function(s) { ss.add(s[0] + new Array(maxlen-s[0].length+1).join(" "), s[1]); });
+	if(this.suites.length > 0) this.suite.run();
+};
 
 BM.prototype.add = function(msg, test) {
-	this.suite.add(msg, {
+	this.suites.push([msg, {
 		onCycle: test_cycle, 
@@ -26,5 +32,6 @@ onComplete: test_end,
 		fn: test
-	});
+	}]);
+	this.maxlen = Math.max(this.maxlen, msg.length);
 };
 
 module.exports = BM;

README.md

@@ -36,4 +36,13 @@ # crc32
 
-`make perf` will run performance tests.
+`make perf` will run algorithmic performance tests (which should justify certain
+decisions in the code).  
 
+`make perf-all` compares the performance of various crc-32 algorithms that
+implement the correct form (note that the SSE intrinsic is designed for the 
+CRC32C checksum and uses a different polynomial).
+
+Unexpected code patterns were based on performance testing in node and browser:
+
+- [Loop unrolling helps!](http://jsperf.com/crc32-table/2)
+
 ## In the future ... 
@@ -50,3 +59,3 @@
 
-[![Build Status](https://travis-ci.org/SheetJS/js-crc32.png?branch=master)](https://travis-ci.org/SheetJS/js-crc32)
+[![Build Status](https://travis-ci.org/SheetJS/js-crc32.svg?branch=master)](https://travis-ci.org/SheetJS/js-crc32)
 
@@ -53,0 +62,0 @@ [![Coverage Status](https://coveralls.io/repos/SheetJS/js-crc32/badge.png?branch=master)](https://coveralls.io/r/SheetJS/js-crc32?branch=master)

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Found 1 instance in 1 package

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Package accesses environment variables, which may be a sign of credential stuffing or data theft.

Found 1 instance in 1 package

Fixed alerts

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Improved metrics

Total package byte prevSize

170353

increased by8.84%

Number of package files

33

increased by13.79%

Lines of code

5839

increased by3.53%

Number of lines in readme file

64

increased by16.36%

Worsened metrics

Number of low supply chain risk alerts

11

increased by22.22%

No dependency changes