Merge pull request #63 from humphd/zlib

Add zlib adapter

README.md

@@ -143,21 +143,26 @@ IDBFS based file systems can acquire new functionality by using adapters. These
 of storage providers without altering them in anway. An adapter can be used with any provider, and multiple
 adapters can be used together in order to compose complex functionality on top of a provider.
 
-There are currently 4 adapters available:
+There are currently 5 adapters available:
+* `FileSystem.adapters.Compression(provider)` - a default compression adapter that uses [Zlib](https://github.com/imaya/zlib.js)
+* `FileSystem.adapters.Encryption(passphrase, provider)` - a default encryption adapter that uses [AES encryption](http://code.google.com/p/crypto-js/#AES)
+
+You can also pick from other encryption cipher algorithms:
 * `FileSystem.adapters.AES(passphrase, provider)` - extends a provider with [AES encryption](http://code.google.com/p/crypto-js/#AES)
 * `FileSystem.adapters.TripleDES(passphrase, provider)` - extends a provider with [TripleDES encryption](http://code.google.com/p/crypto-js/#DES,_Triple_DES)
 * `FileSystem.adapters.Rabbit(passphrase, provider)` - extends a provider with [Rabbit encryption](http://code.google.com/p/crypto-js/#Rabbit)
-* `FileSystem.adapters.Encryption(passphrase, provider)` - a default encryption adapter that uses [AES encryption](http://code.google.com/p/crypto-js/#AES)
 
 ```javascript
 var FileSystem = IDBFS.FileSystem;
 var providers = FileSystem.providers;
 var adapters = FileSystem.adapters;
 
-// Create a WebSQL-based, Encrypted File System.
+// Create a WebSQL-based, Encrypted, Compressed File System by
+// composing a provider and adatpers.
 var webSQLProvider = new providers.WebSQL();
 var encryptionAdatper = new adapters.Encryption('super-secret-passphrase', webSQLProvider);
-var fs1 = new FileSystem({ provider: encryptionAdapter });
+var compressionAdatper = new adatpers.Compression(encryptionAdapter);
+var fs = new FileSystem({ provider: compressionAdapter });
 ```
 
 You can also write your own adapter if you need to add new capabilities to the providers. Adapters share the same

lib/zlib.js

@@ -0,0 +1,40 @@
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+case 2:Sa(this);break;default:l(Error("unknown BTYPE: "+d))}}return this.t()};
+var Ta=[16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15],Ua=E?new Uint16Array(Ta):Ta,Va=[3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,51,59,67,83,99,115,131,163,195,227,258,258,258],Wa=E?new Uint16Array(Va):Va,Xa=[0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0],Ya=E?new Uint8Array(Xa):Xa,Za=[1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577],$a=E?new Uint16Array(Za):Za,ab=[0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,
+10,11,11,12,12,13,13],bb=E?new Uint8Array(ab):ab,cb=new (E?Uint8Array:Array)(288),Z,db;Z=0;for(db=cb.length;Z<db;++Z)cb[Z]=143>=Z?8:255>=Z?9:279>=Z?7:8;var Ca=R(cb),eb=new (E?Uint8Array:Array)(30),fb,hb;fb=0;for(hb=eb.length;fb<hb;++fb)eb[fb]=5;var Ra=R(eb);function Y(d,a){for(var c=d.g,f=d.e,b=d.input,e=d.c,g;f<a;)g=b[e++],g===u&&l(Error("input buffer is broken")),c|=g<<f,f+=8;g=c&(1<<a)-1;d.g=c>>>a;d.e=f-a;d.c=e;return g}
+function ib(d,a){for(var c=d.g,f=d.e,b=d.input,e=d.c,g=a[0],h=a[1],k,n,q;f<h;){k=b[e++];if(k===u)break;c|=k<<f;f+=8}n=g[c&(1<<h)-1];q=n>>>16;d.g=c>>q;d.e=f-q;d.c=e;return n&65535}
+function Sa(d){function a(a,b,c){var d,f,e,g;for(g=0;g<a;)switch(d=ib(this,b),d){case 16:for(e=3+Y(this,2);e--;)c[g++]=f;break;case 17:for(e=3+Y(this,3);e--;)c[g++]=0;f=0;break;case 18:for(e=11+Y(this,7);e--;)c[g++]=0;f=0;break;default:f=c[g++]=d}return c}var c=Y(d,5)+257,f=Y(d,5)+1,b=Y(d,4)+4,e=new (E?Uint8Array:Array)(Ua.length),g,h,k,n;for(n=0;n<b;++n)e[Ua[n]]=Y(d,3);g=R(e);h=new (E?Uint8Array:Array)(c);k=new (E?Uint8Array:Array)(f);d.o(R(a.call(d,c,g,h)),R(a.call(d,f,g,k)))}
+T.prototype.o=function(d,a){var c=this.a,f=this.b;this.u=d;for(var b=c.length-258,e,g,h,k;256!==(e=ib(this,d));)if(256>e)f>=b&&(this.b=f,c=this.f(),f=this.b),c[f++]=e;else{g=e-257;k=Wa[g];0<Ya[g]&&(k+=Y(this,Ya[g]));e=ib(this,a);h=$a[e];0<bb[e]&&(h+=Y(this,bb[e]));f>=b&&(this.b=f,c=this.f(),f=this.b);for(;k--;)c[f]=c[f++-h]}for(;8<=this.e;)this.e-=8,this.c--;this.b=f};
+T.prototype.I=function(d,a){var c=this.a,f=this.b;this.u=d;for(var b=c.length,e,g,h,k;256!==(e=ib(this,d));)if(256>e)f>=b&&(c=this.f(),b=c.length),c[f++]=e;else{g=e-257;k=Wa[g];0<Ya[g]&&(k+=Y(this,Ya[g]));e=ib(this,a);h=$a[e];0<bb[e]&&(h+=Y(this,bb[e]));f+k>b&&(c=this.f(),b=c.length);for(;k--;)c[f]=c[f++-h]}for(;8<=this.e;)this.e-=8,this.c--;this.b=f};
+T.prototype.f=function(){var d=new (E?Uint8Array:Array)(this.b-32768),a=this.b-32768,c,f,b=this.a;if(E)d.set(b.subarray(32768,d.length));else{c=0;for(f=d.length;c<f;++c)d[c]=b[c+32768]}this.l.push(d);this.q+=d.length;if(E)b.set(b.subarray(a,a+32768));else for(c=0;32768>c;++c)b[c]=b[a+c];this.b=32768;return b};
+T.prototype.J=function(d){var a,c=this.input.length/this.c+1|0,f,b,e,g=this.input,h=this.a;d&&("number"===typeof d.v&&(c=d.v),"number"===typeof d.F&&(c+=d.F));2>c?(f=(g.length-this.c)/this.u[2],e=258*(f/2)|0,b=e<h.length?h.length+e:h.length<<1):b=h.length*c;E?(a=new Uint8Array(b),a.set(h)):a=h;return this.a=a};
+T.prototype.t=function(){var d=0,a=this.a,c=this.l,f,b=new (E?Uint8Array:Array)(this.q+(this.b-32768)),e,g,h,k;if(0===c.length)return E?this.a.subarray(32768,this.b):this.a.slice(32768,this.b);e=0;for(g=c.length;e<g;++e){f=c[e];h=0;for(k=f.length;h<k;++h)b[d++]=f[h]}e=32768;for(g=this.b;e<g;++e)b[d++]=a[e];this.l=[];return this.buffer=b};
+T.prototype.H=function(){var d,a=this.b;E?this.B?(d=new Uint8Array(a),d.set(this.a.subarray(0,a))):d=this.a.subarray(0,a):(this.a.length>a&&(this.a.length=a),d=this.a);return this.buffer=d};function jb(d){if("string"===typeof d){var a=d.split(""),c,f;c=0;for(f=a.length;c<f;c++)a[c]=(a[c].charCodeAt(0)&255)>>>0;d=a}for(var b=1,e=0,g=d.length,h,k=0;0<g;){h=1024<g?1024:g;g-=h;do b+=d[k++],e+=b;while(--h);b%=65521;e%=65521}return(e<<16|b)>>>0};function kb(d,a){var c,f;this.input=d;this.c=0;if(a||!(a={}))a.index&&(this.c=a.index),a.verify&&(this.M=a.verify);c=d[this.c++];f=d[this.c++];switch(c&15){case lb:this.method=lb;break;default:l(Error("unsupported compression method"))}0!==((c<<8)+f)%31&&l(Error("invalid fcheck flag:"+((c<<8)+f)%31));f&32&&l(Error("fdict flag is not supported"));this.A=new T(d,{index:this.c,bufferSize:a.bufferSize,bufferType:a.bufferType,resize:a.resize})}
+kb.prototype.p=function(){var d=this.input,a,c;a=this.A.p();this.c=this.A.c;this.M&&(c=(d[this.c++]<<24|d[this.c++]<<16|d[this.c++]<<8|d[this.c++])>>>0,c!==jb(a)&&l(Error("invalid adler-32 checksum")));return a};var lb=8;function mb(d,a){this.input=d;this.a=new (E?Uint8Array:Array)(32768);this.h=$.k;var c={},f;if((a||!(a={}))&&"number"===typeof a.compressionType)this.h=a.compressionType;for(f in a)c[f]=a[f];c.outputBuffer=this.a;this.z=new ia(this.input,c)}var $=na;
+mb.prototype.j=function(){var d,a,c,f,b,e,g,h=0;g=this.a;d=lb;switch(d){case lb:a=Math.LOG2E*Math.log(32768)-8;break;default:l(Error("invalid compression method"))}c=a<<4|d;g[h++]=c;switch(d){case lb:switch(this.h){case $.NONE:b=0;break;case $.r:b=1;break;case $.k:b=2;break;default:l(Error("unsupported compression type"))}break;default:l(Error("invalid compression method"))}f=b<<6|0;g[h++]=f|31-(256*c+f)%31;e=jb(this.input);this.z.b=h;g=this.z.j();h=g.length;E&&(g=new Uint8Array(g.buffer),g.length<=
+h+4&&(this.a=new Uint8Array(g.length+4),this.a.set(g),g=this.a),g=g.subarray(0,h+4));g[h++]=e>>24&255;g[h++]=e>>16&255;g[h++]=e>>8&255;g[h++]=e&255;return g};function nb(d,a){var c,f,b,e;if(Object.keys)c=Object.keys(a);else for(f in c=[],b=0,a)c[b++]=f;b=0;for(e=c.length;b<e;++b)f=c[b],z(d+"."+f,a[f])};z("Zlib.Inflate",kb);z("Zlib.Inflate.prototype.decompress",kb.prototype.p);nb("Zlib.Inflate.BufferType",{ADAPTIVE:Ba.C,BLOCK:Ba.D});z("Zlib.Deflate",mb);z("Zlib.Deflate.compress",function(d,a){return(new mb(d,a)).j()});z("Zlib.Deflate.prototype.compress",mb.prototype.j);nb("Zlib.Deflate.CompressionType",{NONE:$.NONE,FIXED:$.r,DYNAMIC:$.k});}).call(this);

src/adapters/adapters.js

@@ -1,6 +1,7 @@
 define(function(require) {
 
   var CryptoAdapters = require('src/adapters/crypto');
+  var ZlibAdapter = require('src/adapters/zlib');
 
   return {
 
@@ -8,7 +9,12 @@ define(function(require) {
     AES: CryptoAdapters.AES,
     TripleDES: CryptoAdapters.TripleDES,
     Rabbit: CryptoAdapters.Rabbit,
-    // Convenience encryption wrapper (default to AES)
+
+    // Compression Adapters
+    Zlib: ZlibAdapter,
+
+    // Convenience adapters (provide default choices)
+    Compression: ZlibAdapter,
     Encryption: CryptoAdapters.AES
 
   };

src/adapters/crypto.js

@@ -8,6 +8,41 @@ define(function(require) {
   require("crypto-js/rollups/rabbit");
 
 
+  // Move back and forth from Uint8Arrays and CryptoJS WordArray
+  // See http://code.google.com/p/crypto-js/#The_Cipher_Input and
+  // https://groups.google.com/forum/#!topic/crypto-js/TOb92tcJlU0
+  var WordArray = CryptoJS.lib.WordArray;
+  function fromWordArray(wordArray) {
+    var words = wordArray.words;
+    var sigBytes = wordArray.sigBytes;
+    var u8 = new Uint8Array(sigBytes);
+    var b;
+    for (var i = 0; i < sigBytes; i++) {
+      b = (words[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff;
+      u8[i] = b;
+    }
+    return u8;
+  }
+  function toWordArray(u8arr) {
+    var len = u8arr.length;
+    var words = [];
+    for (var i = 0; i < len; i++) {
+      words[i >>> 2] |= (u8arr[i] & 0xff) << (24 - (i % 4) * 8);
+    }
+    return WordArray.create(words, len);
+  }
+
+
+  // UTF8 Text De/Encoders
+  require('encoding');
+  function encode(str) {
+    return (new TextEncoder('utf-8')).encode(str);
+  }
+  function decode(u8arr) {
+    return (new TextDecoder('utf-8')).decode(u8arr);
+  }
+
+
   function CryptoContext(context, encrypt, decrypt) {
     this.context = context;
     this.encrypt = encrypt;
@@ -43,13 +78,34 @@ define(function(require) {
     // prompting the user to enter it when the file system is being opened.
     function CryptoAdapter(passphrase, provider) {
       this.provider = provider;
-      this.encrypt = function(plain) {
+
-        return CryptoJS[encryptionType].encrypt(plain, passphrase)
+      // Cache cipher algorithm we'll use in encrypt/decrypt
-                                       .toString();
+      var cipher = CryptoJS[encryptionType];
+
+      // To encrypt:
+      //   1) accept a buffer (Uint8Array) containing binary data
+      //   2) convert the buffer to a CipherJS WordArray
+      //   3) encrypt the WordArray using the chosen cipher algorithm + passphrase
+      //   4) convert the resulting ciphertext to a UTF8 encoded Uint8Array and return
+      this.encrypt = function(buffer) {
+        var wordArray = toWordArray(buffer);
+        var encrypted = cipher.encrypt(wordArray, passphrase);
+        var utf8EncodedBuf = encode(encrypted);
+        return utf8EncodedBuf;
       };
-      this.decrypt = function(encrypted) {
+
-        return CryptoJS[encryptionType].decrypt(encrypted, passphrase)
+      // To decrypt:
-                                       .toString(CryptoJS.enc.Utf8);
+      //   1) accept a buffer (Uint8Array) containing a UTF8 encoded Uint8Array
+      //   2) convert the buffer to string (i.e., the ciphertext we got from encrypting)
+      //   3) decrypt the ciphertext string
+      //   4) convert the decrypted cipherParam object to a UTF8 string
+      //   5) encode the UTF8 string to a Uint8Array buffer and return
+      this.decrypt = function(buffer) {
+        var encryptedStr = decode(buffer);
+        var decrypted = cipher.decrypt(encryptedStr, passphrase);
+        var decryptedUtf8 = decrypted.toString(CryptoJS.enc.Utf8);
+        var utf8EncodedBuf = encode(decryptedUtf8);
+        return utf8EncodedBuf;
       };
     }
     CryptoAdapter.isSupported = function() {

src/adapters/zlib.js

@@ -0,0 +1,63 @@
+define(function(require) {
+
+  // Zlib compression, see
+  // https://github.com/imaya/zlib.js/blob/master/bin/zlib.min.js
+  require("zlib");
+
+  var Inflate = Zlib.Inflate;
+  function inflate(compressed) {
+    return (new Inflate(compressed)).decompress();
+  }
+
+  var Deflate = Zlib.Deflate;
+  function deflate(buffer) {
+    return (new Deflate(buffer)).compress();
+  }
+
+  function ZlibContext(context) {
+    this.context = context;
+  }
+  ZlibContext.prototype.clear = function(callback) {
+    this.context.clear(callback);
+  };
+  ZlibContext.prototype.get = function(key, callback) {
+    this.context.get(key, function(err, result) {
+      if(err) {
+        callback(err);
+        return;
+      }
+      // Deal with result being null
+      if(result) {
+        result = inflate(result);
+      }
+      callback(null, result);
+    });
+  };
+  ZlibContext.prototype.put = function(key, value, callback) {
+    value = deflate(value);
+    this.context.put(key, value, callback);
+  };
+  ZlibContext.prototype.delete = function(key, callback) {
+    this.context.delete(key, callback);
+  };
+
+
+  function ZlibAdapter(provider, inflate, deflate) {
+    this.provider = provider;
+  }
+  ZlibAdapter.isSupported = function() {
+    return true;
+  };
+
+  ZlibAdapter.prototype.open = function(callback) {
+    this.provider.open(callback);
+  };
+  ZlibAdapter.prototype.getReadOnlyContext = function() {
+    return new ZlibContext(this.provider.getReadOnlyContext());
+  };
+  ZlibAdapter.prototype.getReadWriteContext = function() {
+    return new ZlibContext(this.provider.getReadWriteContext());
+  };
+
+  return ZlibAdapter;
+});

tests/spec/adapters/adapters.general.spec.js

@@ -1,20 +1,31 @@
 define(["IDBFS"], function(IDBFS) {
 
-  // We reuse the same set of tests for all crypto adapters.
+  // We reuse the same set of tests for all adapters.
-  // buildTestsFor() creates a set of tests bound to a crypto
+  // buildTestsFor() creates a set of tests bound to an
   // adapter, and uses a Memory() provider internally.
 
-  function buildTestsFor(adapterName) {
+  function buildTestsFor(adapterName, buildAdapter) {
-    var passphrase = '' + Date.now();
+    function encode(str) {
+      // TextEncoder is either native, or shimmed by IDBFS
+      return (new TextEncoder("utf-8")).encode(str);
+    }
+
+    // Make some string + binary buffer versions of things we'll need
+    var valueStr  = "value", valueBuffer = encode(valueStr);
+    var value1Str = "value1", value1Buffer = encode(value1Str);
+    var value2Str = "value2", value2Buffer = encode(value2Str);
 
     function createProvider() {
       var memoryProvider = new IDBFS.FileSystem.providers.Memory();
-      return new IDBFS.FileSystem.adapters[adapterName](passphrase, memoryProvider);
+      return buildAdapter(memoryProvider);
     }
 
     describe("IDBFS.FileSystem.adapters." + adapterName, function() {
       it("is supported -- if it isn't, none of these tests can run.", function() {
-        expect(IDBFS.FileSystem.adapters[adapterName].isSupported()).toEqual(true);
+        // Allow for combined adapters (e.g., 'AES+Zlib') joined by '+'
+        adapterName.split('+').forEach(function(name) {
+          expect(IDBFS.FileSystem.adapters[name].isSupported()).toEqual(true);
+        });
       });
 
       it("has open, getReadOnlyContext, and getReadWriteContext instance methods", function() {
@@ -47,7 +58,7 @@ define(["IDBFS"], function(IDBFS) {
         });
       });
 
-      describe("Read/Write operations on a Memory provider with an " + adapterName + "adapter", function() {
+      describe("Read/Write operations on a Memory provider with an " + adapterName + " adapter", function() {
         it("should allow put() and get()", function() {
           var complete = false;
           var _error, _result;
@@ -57,7 +68,7 @@ define(["IDBFS"], function(IDBFS) {
             _error = err;
 
             var context = provider.getReadWriteContext();
-            context.put("key", "value", function(err, result) {
+            context.put("key", valueBuffer, function(err, result) {
               _error = _error || err;
               context.get("key", function(err, result) {
                 _error = _error || err;
@@ -74,7 +85,7 @@ define(["IDBFS"], function(IDBFS) {
 
           runs(function() {
             expect(_error).toEqual(null);
-            expect(_result).toEqual("value");
+            expect(_result).toEqual(valueBuffer);
           });
         });
 
@@ -87,7 +98,7 @@ define(["IDBFS"], function(IDBFS) {
             _error = err;
 
             var context = provider.getReadWriteContext();
-            context.put("key", "value", function(err, result) {
+            context.put("key", valueBuffer, function(err, result) {
               _error = _error || err;
               context.delete("key", function(err, result) {
                 _error = _error || err;
@@ -120,9 +131,9 @@ define(["IDBFS"], function(IDBFS) {
             _error = err;
 
             var context = provider.getReadWriteContext();
-            context.put("key1", "value1", function(err, result) {
+            context.put("key1", value1Buffer, function(err, result) {
               _error = _error || err;
-              context.put("key2", "value2", function(err, result) {
+              context.put("key2", value2Buffer, function(err, result) {
                 _error = _error || err;
 
                 context.clear(function(err) {
@@ -164,7 +175,7 @@ define(["IDBFS"], function(IDBFS) {
             _error = err;
 
             var context = provider.getReadOnlyContext();
-            context.put("key1", "value1", function(err, result) {
+            context.put("key1", value1Buffer, function(err, result) {
               _error = _error || err;
               _result = result;
 
@@ -185,8 +196,32 @@ define(["IDBFS"], function(IDBFS) {
     });
   }
 
-  buildTestsFor('AES');
+
-  buildTestsFor('TripleDES');
+  // Encryption
-  buildTestsFor('Rabbit');
+  buildTestsFor('AES', function buildAdapter(provider) {
+    var passphrase = '' + Date.now();
+    return new IDBFS.FileSystem.adapters.AES(passphrase, provider);
+  });
+  buildTestsFor('TripleDES', function buildAdapter(provider) {
+    var passphrase = '' + Date.now();
+    return new IDBFS.FileSystem.adapters.TripleDES(passphrase, provider);
+  });
+  buildTestsFor('Rabbit', function buildAdapter(provider) {
+    var passphrase = '' + Date.now();
+    return new IDBFS.FileSystem.adapters.Rabbit(passphrase, provider);
+  });
+
+  // Compression
+  buildTestsFor('Zlib', function buildAdapter(provider) {
+    return new IDBFS.FileSystem.adapters.Zlib(provider);
+  });
+
+  // AES + Zlib together
+  buildTestsFor('AES+Zlib', function buildAdapter(provider) {
+    var passphrase = '' + Date.now();
+    var zlib = new IDBFS.FileSystem.adapters.Zlib(provider);
+    var AESwithZlib = new IDBFS.FileSystem.adapters.AES(passphrase, zlib);
+    return AESwithZlib;
+  });
 
 });

tests/spec/adapters/adapters.spec.js

@@ -19,5 +19,13 @@ define(["IDBFS"], function(IDBFS) {
     it("has a default Encryption constructor", function() {
       expect(typeof IDBFS.FileSystem.adapters.Encryption).toEqual('function');
     });
+
+    it("has a Zlib constructor", function() {
+      expect(typeof IDBFS.FileSystem.adapters.Zlib).toEqual('function');
+    });
+
+    it("has a default Compression constructor", function() {
+      expect(typeof IDBFS.FileSystem.adapters.Compression).toEqual('function');
+    });
   });
 });

tests/test-manifest.js

@@ -36,7 +36,7 @@ define([
 
   // IDBFS.FileSystem.adapters.*
   "spec/adapters/adapters.spec",
-  "spec/adapters/adapters.crypto.spec",
+  "spec/adapters/adapters.general.spec",
 
   // Ported node.js tests (filenames match names in https://github.com/joyent/node/tree/master/test)
   "spec/node-js/simple/test-fs-mkdir",