adler32 - npm Package Compare versions

Comparing version 0.1.5 to 0.1.6

index.js

 #!/usr/bin/env node
 "use strict";
 
-/**
- * Largest prime smaller than 2^16 (65536)
- */
-var BASE = 65521;
+var algorithm = require('./lib/algorithm');
+var Hash = require('./lib/Hash');
+var register = require('./lib/register');
 
-/**
- * Largest value n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1
- *
- * NMAX is just how often modulo needs to be taken of the two checksum word halves to prevent overflowing a 32 bit
- * integer. This is an optimization. We "could" take the modulo after each byte, and it must be taken before each
- * digest.
- */
-var NMAX = 5552;
-
-exports.sum = function(buf, adler)
-{
-	if (adler == null)
-		adler = 1;
-
-	var a = adler & 0xFFFF,
-		b = (adler >>> 16) & 0xFFFF,
-		i = 0,
-		max = buf.length,
-		n, value;
-
-	while (i < max)
-	{
-		n = Math.min(NMAX, max - i);
-
-		do
-		{
-			a += buf[i++]<<0;
-			b += a;
-		}
-		while (--n);
-
-		a %= BASE;
-		b %= BASE;
-	}
-
-	return ((b << 16) | a) >>> 0;
-};
-
-exports.roll = function(sum, length, oldByte, newByte)
-{
-	var a = sum & 0xFFFF,
-		b = (sum >>> 16) & 0xFFFF;
-
-	if (newByte != null)
-	{
-		a = (a - oldByte + newByte + BASE) % BASE;
-		b = (b - ((length * oldByte) % BASE) + a - 1 + BASE) % BASE;
-	}
-	else
-	{
-		a = (a - oldByte + BASE) % BASE;
-		b = (b - ((length * oldByte) % BASE) - 1 + BASE) % BASE;
-	}
-
-	return ((b << 16) | a) >>> 0;
-};
+exports.sum = algorithm.sum.bind(algorithm);
+exports.roll = algorithm.roll.bind(algorithm);
+exports.Hash = Hash;
+exports.register = register;

package.json

 {
   "name": "adler32",
-  "version": "0.1.5",
+  "version": "0.1.6",
   "description": "Adler-32 hashing algorithm",
   "main": "index.js",
   "devDependencies": {
-    "mocha": "^1.20.1",
-    "mhash": "^1.0.0",
-    "should": "^4.0.4",
+    "mocha": "^2.2.5",
+    "mhash": "^2.0.0",
+    "should": "^7.0.2",
     "random-buffer": "^0.1.0"
   },
   "scripts": {
-    "test": "mocha -t 10000 -R spec ./test.js",
+    "test": "mocha -t 30000 -R spec ./test.js",
     "bench": "./bench.js"
@@ -15,0 +15,0 @@ },

README.md

@@ -51,2 +51,30 @@ # adler32 [![Build Status](https://travis-ci.org/ChrisAckerman/adler32.svg?branch=master)](https://travis-ci.org/ChrisAckerman/adler32)
 
+## `crypto` Module Integration
+
+The adler32 algorithm can be integrated with the
+[Node.js crypto module](http://nodejs.org/api/crypto.html#crypto_crypto_createhash_algorithm). Calling the
+`adler32.register()` static method will add the 'adler32' key to the crypto module's algorithm list.
+
+Create an adler32 Hash instance using the crypto module:
+
+	// Adds the 'adler32' key to the crypto.createHash() method.
+	adler32.register();
+
+	// Get an adler32 hash instance.
+	var hash = crypto.createHash('adler32');
+
+	// Add ascii data to the hash.
+	hash.update(data, 'ascii');
+
+	// Get a digest of all data added to the hash.
+	var digest = hash.digest('hex');
+
+Create an adler32 Hash instance directly:
+
+	var hash = new adler32.Hash();
+
+Like the `crypto.Hash` class, `adler32.Hash` extends the `stream.Transform` class. You can use the stream `.write()` and
+`.read()` methods in place of the deprecated `.update()` and `.digest()` methods. See the
+[Node.js stream module](http://nodejs.org/api/stream.html) documentation for more information about streaming.
+
 ## Caveats
@@ -53,0 +81,0 @@

test.js

@@ -6,3 +6,3 @@ #!/usr/bin/env node
 var Adler32 = require('./');
-var hash = require('mhash').hash;
+var mhash = require('mhash');
 var rand = require('random-buffer');
@@ -14,3 +14,3 @@
 describe('Adler32', function() {
-	describe('.sum(buf, adler = 1)', function() {
+	describe('.sum(buf, [adler = 1])', function() {
 		var sum = Adler32.sum(buf);
@@ -24,3 +24,3 @@
 		it('should match the sum calculated by mhash', function() {
-			sum.should.be.exactly(parseInt(hash('adler32', buf), 16));
+			sum.should.be.exactly(parseInt(mhash('adler32', buf), 16));
 		});
@@ -40,3 +40,3 @@
 
-	describe('.roll(sum, length, oldByte, newByte = null)', function() {
+	describe('.roll(sum, length, oldByte, [newByte = null])', function() {
 		it('should result in the same value as sum for each offset chunk of size 64', function() {
@@ -78,2 +78,65 @@ rollTest(64);
 	});
+
+	describe('.Hash', function () {
+		it('should hash a string', function() {
+			// Example taken from http://en.wikipedia.org/wiki/Adler-32.
+			var hash = new Adler32.Hash();
+			hash.update('Wikipedia');
+			hash.digest('hex').toLowerCase().should.be.exactly('11e60398');
+		});
+
+		it('should hash a string in parts', function() {
+			var hash = new Adler32.Hash();
+			hash.update('Wiki');
+			hash.update('pedia');
+			hash.digest('hex').toLowerCase().should.be.exactly('11e60398');
+		});
+
+		it('should work as a Transform stream', function() {
+			var hash = new Adler32.Hash({encoding: 'hex'});
+			hash.write('Wiki');
+			hash.write('pedia');
+			hash.end();
+			hash.read().toLowerCase().should.be.exactly('11e60398');
+		});
+
+		it('should throw a TypeError if update() is called after digest()', function() {
+			var hash = new Adler32.Hash();
+			hash.update('Wikipedia');
+			hash.digest('hex');
+			(function() {
+				hash.update('Moar!');
+			}).should.throw(TypeError);
+		});
+
+		it('should throw an Error if digest() is called more than once', function() {
+			var hash = new Adler32.Hash();
+			hash.digest('hex');
+			(function() {
+				hash.digest('hex');
+			}).should.throw(Error);
+		});
+	});
+
+	describe('.register()', function () {
+		Adler32.register();
+
+		var crypto = require('crypto');
+
+		it('should make it so crypto.getHashes() contains adler32', function () {
+			crypto.getHashes().indexOf('adler32').should.not.equal(-1);
+		});
+
+		it('should make it so crypto.createHash(algorithm) works for adler32', function () {
+			var hash = crypto.createHash('adler32');
+			should(hash).be.an.instanceOf(Adler32.Hash);
+			hash.update('Wikipedia');
+			hash.digest('hex').toLowerCase().should.be.exactly('11e60398');
+		});
+
+		it('should not remove other crypto hash algorithms', function () {
+			crypto.getHashes().indexOf('sha256').should.not.equal(-1);
+			should.exist(crypto.createHash('sha256'));
+		});
+	});
 });
@@ -80,0 +143,0 @@

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Improved metrics

Total package byte prevSize

15290

increased by50.95%

Number of package files

12

increased by20%

Lines of code

253

increased by105.69%

Number of lines in readme file

116

increased by31.82%

Worsened metrics

Number of medium supply chain risk alerts

1

increased byInfinity%

No dependency changes