Squashed commit of the following:

commit 7c6cacc59b27660fabacb55d668ef099b222a9e6
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Sat Nov 3 08:52:51 2018 -0300

    code review: finalize support for wasm-based hntrie

commit 8596ed80e3bdac2c36e3c860b51e7189f6bc8487
Merge: cbe1f2e 000eb82
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Sat Nov 3 08:41:40 2018 -0300

    Merge branch 'master' of github.com:gorhill/uBlock into trie-wasm

commit cbe1f2e2f38484d42af3204ec7f1b5decd30f99e
Merge: 270fc7f dbb7e80
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Fri Nov 2 17:43:20 2018 -0300

    Merge branch 'master' of github.com:gorhill/uBlock into trie-wasm

commit 270fc7f9b3b73d79e6355522c1a42ce782fe7e5c
Merge: d2a89cf d693d4f
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Fri Nov 2 16:21:08 2018 -0300

    Merge branch 'master' of github.com:gorhill/uBlock into trie-wasm

commit d2a89cf28f0816ffd4617c2c7b4ccfcdcc30e1b4
Merge: d7afc78 649f82f
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Fri Nov 2 14:54:58 2018 -0300

    Merge branch 'master' of github.com:gorhill/uBlock into trie-wasm

commit d7afc78b5f5675d7d34c5a1d0ec3099a77caef49
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Fri Nov 2 13:56:11 2018 -0300

    finalize wasm-based hntrie implementation

commit e7b9e043cf36ad055791713e34eb0322dec84627
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Fri Nov 2 08:14:02 2018 -0300

    add first-pass implementation of wasm version of hntrie

commit 1015cb34624f3ef73ace58b58fe4e03dfc59897f
Author: Raymond Hill <rhill@raymondhill.net>
Date:   Wed Oct 31 17:16:47 2018 -0300

    back up draft work toward experimenting with wasm hntries

src/js/background.js

@@ -33,12 +33,12 @@ if ( vAPI.webextFlavor === undefined ) {
 
 /******************************************************************************/
 
-var µBlock = (function() { // jshint ignore:line
+const µBlock = (function() { // jshint ignore:line
 
-    var oneSecond = 1000,
+    const oneSecond = 1000,
-        oneMinute = 60 * oneSecond;
+          oneMinute = 60 * oneSecond;
 
-    var hiddenSettingsDefault = {
+    const hiddenSettingsDefault = {
         assetFetchTimeout: 30,
         autoUpdateAssetFetchPeriod: 120,
         autoUpdatePeriod: 7,
@@ -56,7 +56,7 @@ var µBlock = (function() { // jshint ignore:line
         userResourcesLocation: 'unset'
     };
 
-    var whitelistDefault = [
+    const whitelistDefault = [
         'about-scheme',
         'chrome-extension-scheme',
         'chrome-scheme',

src/js/start.js

@@ -29,7 +29,7 @@
 
 /******************************************************************************/
 
-var µb = µBlock;
+const µb = µBlock;
 
 /******************************************************************************/
 
@@ -287,7 +287,12 @@ var onFirstFetchReady = function(fetched) {
     onVersionReady(fetched.version);
     onCommandShortcutsReady(fetched.commandShortcuts);
 
-    µb.loadPublicSuffixList(onPSLReady);
+    Promise.all([
+        µb.loadPublicSuffixList(),
+        µb.staticNetFilteringEngine.readyToUse()
+    ]).then(( ) => {
+        onPSLReady();
+    });
     µb.loadRedirectResources();
 };
 

src/js/static-net-filtering.js

@@ -20,7 +20,7 @@
 */
 
 /* jshint bitwise: false */
-/* global punycode, HNTrieBuilder */
+/* global punycode, hnTrieManager */
 
 'use strict';
 
@@ -30,7 +30,7 @@
 
 /******************************************************************************/
 
-var µb = µBlock;
+const µb = µBlock;
 
 // fedcba9876543210
 //       |    | |||
@@ -43,15 +43,15 @@ var µb = µBlock;
 //       |    +-------- bit 4- 8: type [0 - 31]
 //       +------------- bit 9-15: unused
 
-var BlockAction = 0 << 0;
+const BlockAction = 0 << 0;
-var AllowAction = 1 << 0;
+const AllowAction = 1 << 0;
-var Important   = 1 << 1;
+const Important   = 1 << 1;
-var AnyParty    = 0 << 2;
+const AnyParty    = 0 << 2;
-var FirstParty  = 1 << 2;
+const FirstParty  = 1 << 2;
-var ThirdParty  = 2 << 2;
+const ThirdParty  = 2 << 2;
 
-var AnyType = 0 << 4;
+const AnyType = 0 << 4;
-var typeNameToTypeValue = {
+const typeNameToTypeValue = {
            'no_type':  0 << 4,
         'stylesheet':  1 << 4,
              'image':  2 << 4,
@@ -75,9 +75,9 @@ var typeNameToTypeValue = {
             'webrtc': 19 << 4,
        'unsupported': 20 << 4
 };
-var otherTypeBitValue = typeNameToTypeValue.other;
+const otherTypeBitValue = typeNameToTypeValue.other;
 
-var typeValueToTypeName = {
+const typeValueToTypeName = {
      1: 'stylesheet',
      2: 'image',
      3: 'object',
@@ -100,16 +100,16 @@ var typeValueToTypeName = {
     20: 'unsupported'
 };
 
-var BlockAnyTypeAnyParty = BlockAction | AnyType | AnyParty;
+const BlockAnyTypeAnyParty = BlockAction | AnyType | AnyParty;
-var BlockAnyType = BlockAction | AnyType;
+const BlockAnyType = BlockAction | AnyType;
-var BlockAnyParty = BlockAction | AnyParty;
+const BlockAnyParty = BlockAction | AnyParty;
 
-var AllowAnyTypeAnyParty = AllowAction | AnyType | AnyParty;
+const AllowAnyTypeAnyParty = AllowAction | AnyType | AnyParty;
-var AllowAnyType = AllowAction | AnyType;
+const AllowAnyType = AllowAction | AnyType;
-var AllowAnyParty = AllowAction | AnyParty;
+const AllowAnyParty = AllowAction | AnyParty;
 
-var genericHideException = AllowAction | AnyParty | typeNameToTypeValue.generichide,
+const genericHideException = AllowAction | AnyParty | typeNameToTypeValue.generichide,
-    genericHideImportant = BlockAction | AnyParty | typeNameToTypeValue.generichide | Important;
+      genericHideImportant = BlockAction | AnyParty | typeNameToTypeValue.generichide | Important;
 
 // ABP filters: https://adblockplus.org/en/filters
 // regex tester: http://regex101.com/
@@ -119,7 +119,7 @@ var genericHideException = AllowAction | AnyParty | typeNameToTypeValue.generich
 // See the following as short-lived registers, used during evaluation. They are
 // valid until the next evaluation.
 
-var pageHostnameRegister = '',
+let pageHostnameRegister = '',
     requestHostnameRegister = '';
 //var filterRegister = null;
 //var categoryRegister = '';
@@ -127,13 +127,13 @@ var pageHostnameRegister = '',
 // Local helpers
 
 // Be sure to not confuse 'example.com' with 'anotherexample.com'
-var isFirstParty = function(domain, hostname) {
+const isFirstParty = function(domain, hostname) {
     return hostname.endsWith(domain) &&
           (hostname.length === domain.length ||
            hostname.charCodeAt(hostname.length - domain.length - 1) === 0x2E /* '.' */);
 };
 
-var normalizeRegexSource = function(s) {
+const normalizeRegexSource = function(s) {
     try {
         var re = new RegExp(s);
         return re.source;
@@ -143,12 +143,12 @@ var normalizeRegexSource = function(s) {
     return '';
 };
 
-var rawToRegexStr = function(s, anchor) {
+const rawToRegexStr = function(s, anchor) {
-    var me = rawToRegexStr;
+    let me = rawToRegexStr;
     // https://www.loggly.com/blog/five-invaluable-techniques-to-improve-regex-performance/
     // https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions
     // Also: remove leading/trailing wildcards -- there is no point.
-    var reStr = s.replace(me.escape1, '\\$&')
+    let reStr = s.replace(me.escape1, '\\$&')
                  .replace(me.escape2, '(?:[^%.0-9a-z_-]|$)')
                  .replace(me.escape3, '')
                  .replace(me.escape4, '[^ ]*?');
@@ -175,7 +175,7 @@ rawToRegexStr.reTextHostnameAnchor2 = '^[a-z-]+://(?:[^/?#]+)?';
 
 const filterDataSerialize = µb.CompiledLineIO.serialize;
 
-var toLogDataInternal = function(categoryBits, tokenHash, filter) {
+const toLogDataInternal = function(categoryBits, tokenHash, filter) {
     if ( filter === null ) { return undefined; }
     let logData = filter.logData();
     logData.compiled = filterDataSerialize([
@@ -209,7 +209,7 @@ var toLogDataInternal = function(categoryBits, tokenHash, filter) {
 };
 
 // First character of match must be within the hostname part of the url.
-var isHnAnchored = function(url, matchStart) {
+const isHnAnchored = function(url, matchStart) {
     var hnStart = url.indexOf('://');
     if ( hnStart === -1 ) { return false; }
     hnStart += 3;
@@ -222,9 +222,9 @@ var isHnAnchored = function(url, matchStart) {
     return url.charCodeAt(matchStart - 1) === 0x2E;
 };
 
-var reURLPostHostnameAnchors = /[\/?#]/;
+const reURLPostHostnameAnchors = /[\/?#]/;
 
-var arrayStrictEquals = function(a, b) {
+const arrayStrictEquals = function(a, b) {
     var n = a.length;
     if ( n !== b.length ) { return false; }
     var isArray, x, y;
@@ -251,22 +251,22 @@ var arrayStrictEquals = function(a, b) {
 
 **/
 
-var filterClasses = [],
+const filterClasses = [];
-    filterClassIdGenerator = 0;
+let   filterClassIdGenerator = 0;
 
-var registerFilterClass = function(ctor) {
+const registerFilterClass = function(ctor) {
-    var fid = filterClassIdGenerator++;
+    let fid = filterClassIdGenerator++;
     ctor.fid = ctor.prototype.fid = fid;
     filterClasses[fid] = ctor;
 };
 
-var filterFromCompiledData = function(args) {
+const filterFromCompiledData = function(args) {
     return filterClasses[args[0]].load(args);
 };
 
 /******************************************************************************/
 
-var FilterTrue = function() {
+const FilterTrue = function() {
 };
 
 FilterTrue.prototype.match = function() {
@@ -297,7 +297,7 @@ registerFilterClass(FilterTrue);
 
 /******************************************************************************/
 
-var FilterPlain = function(s, tokenBeg) {
+const FilterPlain = function(s, tokenBeg) {
     this.s = s;
     this.tokenBeg = tokenBeg;
 };
@@ -330,7 +330,7 @@ registerFilterClass(FilterPlain);
 
 /******************************************************************************/
 
-var FilterPlainPrefix0 = function(s) {
+const FilterPlainPrefix0 = function(s) {
     this.s = s;
 };
 
@@ -362,7 +362,7 @@ registerFilterClass(FilterPlainPrefix0);
 
 /******************************************************************************/
 
-var FilterPlainPrefix1 = function(s) {
+const FilterPlainPrefix1 = function(s) {
     this.s = s;
 };
 
@@ -394,7 +394,7 @@ registerFilterClass(FilterPlainPrefix1);
 
 /******************************************************************************/
 
-var FilterPlainHostname = function(s) {
+const FilterPlainHostname = function(s) {
     this.s = s;
 };
 
@@ -429,7 +429,7 @@ registerFilterClass(FilterPlainHostname);
 
 /******************************************************************************/
 
-var FilterPlainLeftAnchored = function(s) {
+const FilterPlainLeftAnchored = function(s) {
     this.s = s;
 };
 
@@ -461,7 +461,7 @@ registerFilterClass(FilterPlainLeftAnchored);
 
 /******************************************************************************/
 
-var FilterPlainRightAnchored = function(s) {
+const FilterPlainRightAnchored = function(s) {
     this.s = s;
 };
 
@@ -493,7 +493,7 @@ registerFilterClass(FilterPlainRightAnchored);
 
 /******************************************************************************/
 
-var FilterExactMatch = function(s) {
+const FilterExactMatch = function(s) {
     this.s = s;
 };
 
@@ -525,7 +525,7 @@ registerFilterClass(FilterExactMatch);
 
 /******************************************************************************/
 
-var FilterPlainHnAnchored = function(s) {
+const FilterPlainHnAnchored = function(s) {
     this.s = s;
 };
 
@@ -558,7 +558,7 @@ registerFilterClass(FilterPlainHnAnchored);
 
 /******************************************************************************/
 
-var FilterGeneric = function(s, anchor) {
+const FilterGeneric = function(s, anchor) {
     this.s = s;
     this.anchor = anchor;
 };
@@ -603,7 +603,7 @@ registerFilterClass(FilterGeneric);
 
 /******************************************************************************/
 
-var FilterGenericHnAnchored = function(s) {
+const FilterGenericHnAnchored = function(s) {
     this.s = s;
 };
 
@@ -642,7 +642,7 @@ registerFilterClass(FilterGenericHnAnchored);
 
 /******************************************************************************/
 
-var FilterGenericHnAndRightAnchored = function(s) {
+const FilterGenericHnAndRightAnchored = function(s) {
     FilterGenericHnAnchored.call(this, s);
 };
 
@@ -682,7 +682,7 @@ registerFilterClass(FilterGenericHnAndRightAnchored);
 
 /******************************************************************************/
 
-var FilterRegex = function(s) {
+const FilterRegex = function(s) {
     this.re = s;
 };
 
@@ -723,7 +723,7 @@ registerFilterClass(FilterRegex);
 
 // Filtering according to the origin.
 
-var FilterOrigin = function() {
+const FilterOrigin = function() {
 };
 
 FilterOrigin.prototype.wrapped = {
@@ -766,7 +766,7 @@ FilterOrigin.prototype.compile = function() {
 
 // *** start of specialized origin matchers
 
-var FilterOriginHit = function(domainOpt) {
+const FilterOriginHit = function(domainOpt) {
     FilterOrigin.call(this);
     this.hostname = domainOpt;
 };
@@ -792,7 +792,7 @@ FilterOriginHit.prototype = Object.create(FilterOrigin.prototype, {
 
 //
 
-var FilterOriginMiss = function(domainOpt) {
+const FilterOriginMiss = function(domainOpt) {
     FilterOrigin.call(this);
     this.hostname = domainOpt.slice(1);
 };
@@ -811,14 +811,15 @@ FilterOriginMiss.prototype = Object.create(FilterOrigin.prototype, {
             var needle = this.hostname, haystack = pageHostnameRegister;
             if ( haystack.endsWith(needle) === false ) { return true; }
             var offset = haystack.length - needle.length;
-            return offset !== 0 && haystack.charCodeAt(offset - 1) !== 0x2E /* '.' */;
+            return offset !== 0 &&
+                   haystack.charCodeAt(offset - 1) !== 0x2E /* '.' */;
         }
     },
 });
 
 //
 
-var FilterOriginHitSet = function(domainOpt) {
+const FilterOriginHitSet = function(domainOpt) {
     FilterOrigin.call(this);
     this.domainOpt = domainOpt.length < 128
         ? domainOpt
@@ -840,17 +841,17 @@ FilterOriginHitSet.prototype = Object.create(FilterOrigin.prototype, {
     },
     matchOrigin: {
         value: function() {
-            if ( this.oneOf === null ) {
+            if ( hnTrieManager.isValidRef(this.oneOf) === false ) {
-                this.oneOf = HNTrieBuilder.fromDomainOpt(this.domainOpt);
+                this.oneOf = hnTrieManager.fromDomainOpt(this.domainOpt);
             }
-            return this.oneOf.matches(pageHostnameRegister);
+            return this.oneOf.matches(pageHostnameRegister) === 1;
         }
     },
 });
 
 //
 
-var FilterOriginMissSet = function(domainOpt) {
+const FilterOriginMissSet = function(domainOpt) {
     FilterOrigin.call(this);
     this.domainOpt = domainOpt.length < 128
         ? domainOpt
@@ -872,17 +873,19 @@ FilterOriginMissSet.prototype = Object.create(FilterOrigin.prototype, {
     },
     matchOrigin: {
         value: function() {
-            if ( this.noneOf === null ) {
+            if ( hnTrieManager.isValidRef(this.noneOf) === false ) {
-                this.noneOf = HNTrieBuilder.fromDomainOpt(this.domainOpt.replace(/~/g, ''));
+                this.noneOf = hnTrieManager.fromDomainOpt(
+                    this.domainOpt.replace(/~/g, '')
+                );
             }
-            return this.noneOf.matches(pageHostnameRegister) === false;
+            return this.noneOf.matches(pageHostnameRegister) === 0;
         }
     },
 });
 
 //
 
-var FilterOriginMixedSet = function(domainOpt) {
+const FilterOriginMixedSet = function(domainOpt) {
     FilterOrigin.call(this);
     this.domainOpt = domainOpt.length < 128
         ? domainOpt
@@ -903,20 +906,16 @@ FilterOriginMixedSet.prototype = Object.create(FilterOrigin.prototype, {
     },
     init: {
         value: function() {
-            var oneOf = [], noneOf = [],
+            let oneOf = [], noneOf = [];
-                hostnames = this.domainOpt.split('|'),
+            for ( let hostname of this.domainOpt.split('|') ) {
-                i = hostnames.length,
-                hostname;
-            while ( i-- ) {
-                hostname = hostnames[i];
                 if ( hostname.charCodeAt(0) === 0x7E /* '~' */ ) {
                     noneOf.push(hostname.slice(1));
                 } else {
                     oneOf.push(hostname);
                 }
             }
-            this.oneOf = HNTrieBuilder.fromIterable(oneOf);
+            this.oneOf = hnTrieManager.fromIterable(oneOf);
-            this.noneOf = HNTrieBuilder.fromIterable(noneOf);
+            this.noneOf = hnTrieManager.fromIterable(noneOf);
         }
     },
     toDomainOpt: {
@@ -926,10 +925,12 @@ FilterOriginMixedSet.prototype = Object.create(FilterOrigin.prototype, {
     },
     matchOrigin: {
         value: function() {
-            if ( this.oneOf === null ) { this.init(); }
+            if ( hnTrieManager.isValidRef(this.oneOf) === false ) {
-            var needle = pageHostnameRegister;
+                this.init();
-            return this.oneOf.matches(needle) &&
+            }
-                   this.noneOf.matches(needle) === false;
+            let needle = pageHostnameRegister;
+            return this.oneOf.matches(needle) === 1 &&
+                   this.noneOf.matches(needle) === 0;
         }
     },
 });
@@ -981,7 +982,7 @@ registerFilterClass(FilterOrigin);
 
 /******************************************************************************/
 
-var FilterDataHolder = function(dataType, dataStr) {
+const FilterDataHolder = function(dataType, dataStr) {
     this.dataType = dataType;
     this.dataStr = dataStr;
     this.wrapped = undefined;
@@ -1024,7 +1025,7 @@ registerFilterClass(FilterDataHolder);
 
 // Helper class for storing instances of FilterDataHolder.
 
-var FilterDataHolderEntry = function(categoryBits, tokenHash, fdata) {
+const FilterDataHolderEntry = function(categoryBits, tokenHash, fdata) {
     this.categoryBits = categoryBits;
     this.tokenHash = tokenHash;
     this.filter = filterFromCompiledData(fdata);
@@ -1047,7 +1048,7 @@ FilterDataHolderEntry.load = function(data) {
 
 // Dictionary of hostnames
 //
-var FilterHostnameDict = function() {
+const FilterHostnameDict = function() {
     this.h = ''; // short-lived register
     this.dict = new Set();
 };
@@ -1138,7 +1139,7 @@ registerFilterClass(FilterHostnameDict);
 
 /******************************************************************************/
 
-var FilterPair = function(a, b) {
+const FilterPair = function(a, b) {
     this.f1 = a;
     this.f2 = b;
     this.f = null;
@@ -1217,7 +1218,7 @@ registerFilterClass(FilterPair);
 
 /******************************************************************************/
 
-var FilterBucket = function(a, b, c) {
+const FilterBucket = function(a, b, c) {
     this.filters = [];
     this.f = null;
     if ( a !== undefined ) {
@@ -1315,7 +1316,7 @@ registerFilterClass(FilterBucket);
 /******************************************************************************/
 /******************************************************************************/
 
-var FilterParser = function() {
+const FilterParser = function() {
     this.cantWebsocket = vAPI.cantWebsocket;
     this.reBadDomainOptChars = /[*+?^${}()[\]\\]/;
     this.reHostnameRule1 = /^[0-9a-z][0-9a-z.-]*[0-9a-z]$/i;
@@ -1933,7 +1934,7 @@ FilterParser.prototype.makeToken = function() {
 /******************************************************************************/
 /******************************************************************************/
 
-var FilterContainer = function() {
+const FilterContainer = function() {
     this.reIsGeneric = /[\^\*]/;
     this.filterParser = new FilterParser();
     this.urlTokenizer = µb.urlTokenizer;
@@ -1960,6 +1961,9 @@ FilterContainer.prototype.reset = function() {
     this.dataFilters = new Map();
     this.filterParser.reset();
 
+    // This will invalidate all hn tries throughout uBO:
+    hnTrieManager.reset();
+
     // Runtime registers
     this.cbRegister = undefined;
     this.thRegister = undefined;
@@ -2052,6 +2056,15 @@ FilterContainer.prototype.freeze = function() {
 
 /******************************************************************************/
 
+// This is necessary for when the filtering engine readiness will depend
+// on asynchronous operations (ex.: when loading a wasm module).
+
+FilterContainer.prototype.readyToUse = function() {
+    return hnTrieManager.readyToUse();
+};
+
+/******************************************************************************/
+
 FilterContainer.prototype.toSelfie = function() {
     let categoriesToSelfie = function(categoryMap) {
         let selfie = [];
@@ -2250,7 +2263,7 @@ FilterContainer.prototype.compileToAtomicFilter = function(
 
     // Only static filter with an explicit type can be redirected. If we reach
     // this point, it's because there is one or more explicit type.
-    if ( parsed.badFilter === false && parsed.redirect ) {
+    if ( parsed.redirect ) {
         let redirects = µb.redirectEngine.compileRuleFromStaticFilter(parsed.raw);
         if ( Array.isArray(redirects) ) {
             for ( let redirect of redirects ) {
@@ -2292,26 +2305,24 @@ FilterContainer.prototype.fromCompiledContent = function(reader) {
 FilterContainer.prototype.matchAndFetchData = function(dataType, requestURL, out, outlog) {
     if ( this.dataFilters.length === 0 ) { return; }
 
-    var url = this.urlTokenizer.setURL(requestURL);
+    let url = this.urlTokenizer.setURL(requestURL);
 
-    requestHostnameRegister = µb.URI.hostnameFromURI(url);
+    pageHostnameRegister = requestHostnameRegister = µb.URI.hostnameFromURI(url);
 
     // We need to visit ALL the matching filters.
-    var toAddImportant = new Map(),
+    let toAddImportant = new Map(),
         toAdd = new Map(),
         toRemove = new Map();
 
-    var entry, f,
+    let tokenHashes = this.urlTokenizer.getTokens(),
-        tokenHashes = this.urlTokenizer.getTokens(),
-        tokenHash, tokenOffset,
         i = 0;
     while ( i < 32 ) {
-        tokenHash = tokenHashes[i++];
+        let tokenHash = tokenHashes[i++];
         if ( tokenHash === 0 ) { break; }
-        tokenOffset = tokenHashes[i++];
+        let tokenOffset = tokenHashes[i++];
-        entry = this.dataFilters.get(tokenHash);
+        let entry = this.dataFilters.get(tokenHash);
         while ( entry !== undefined ) {
-            f = entry.filter;
+            let f = entry.filter;
             if ( f.match(url, tokenOffset) === true ) {
                 if ( entry.categoryBits & 0x001 ) {
                     toRemove.set(f.dataStr, entry);
@@ -2324,9 +2335,9 @@ FilterContainer.prototype.matchAndFetchData = function(dataType, requestURL, out
             entry = entry.next;
         }
     }
-    entry = this.dataFilters.get(this.noTokenHash);
+    let entry = this.dataFilters.get(this.noTokenHash);
     while ( entry !== undefined ) {
-        f = entry.filter;
+        let f = entry.filter;
         if ( f.match(url) === true ) {
             if ( entry.categoryBits & 0x001 ) {
                 toRemove.set(f.dataStr, entry);
@@ -2342,12 +2353,11 @@ FilterContainer.prototype.matchAndFetchData = function(dataType, requestURL, out
     if ( toAddImportant.size === 0 && toAdd.size === 0 ) { return; }
 
     // Remove entries overriden by other filters.
-    var key;
+    for ( let key of toAddImportant.keys() ) {
-    for ( key of toAddImportant.keys() ) {
         toAdd.delete(key);
         toRemove.delete(key);
     }
-    for ( key of toRemove.keys() ) {
+    for ( let key of toRemove.keys() ) {
         if ( key === '' ) {
             toAdd.clear();
             break;
@@ -2355,26 +2365,25 @@ FilterContainer.prototype.matchAndFetchData = function(dataType, requestURL, out
         toAdd.delete(key);
     }
 
-    var logData;
+    for ( let entry of toAddImportant ) {
-    for ( entry of toAddImportant ) {
         out.push(entry[0]);
         if ( outlog === undefined ) { continue; }
-        logData = entry[1].logData();
+        let logData = entry[1].logData();
         logData.source = 'static';
         logData.result = 1;
         outlog.push(logData);
     }
-    for ( entry of toAdd ) {
+    for ( let entry of toAdd ) {
         out.push(entry[0]);
         if ( outlog === undefined ) { continue; }
-        logData = entry[1].logData();
+        let logData = entry[1].logData();
         logData.source = 'static';
         logData.result = 1;
         outlog.push(logData);
     }
     if ( outlog !== undefined ) {
-        for ( entry of toRemove.values()) {
+        for ( let entry of toRemove.values()) {
-            logData = entry.logData();
+            let logData = entry.logData();
             logData.source = 'static';
             logData.result = 2;
             outlog.push(logData);
@@ -2389,20 +2398,19 @@ FilterContainer.prototype.matchAndFetchData = function(dataType, requestURL, out
 
 FilterContainer.prototype.matchTokens = function(bucket, url) {
     // Hostname-only filters
-    var f = bucket.get(this.dotTokenHash);
+    let f = bucket.get(this.dotTokenHash);
     if ( f !== undefined && f.match() === true ) {
         this.thRegister = this.dotTokenHash;
         this.fRegister = f;
         return true;
     }
 
-    var tokenHashes = this.urlTokenizer.getTokens(),
+    let tokenHashes = this.urlTokenizer.getTokens(),
-        tokenHash, tokenOffset,
         i = 0;
     for (;;) {
-        tokenHash = tokenHashes[i++];
+        let tokenHash = tokenHashes[i++];
         if ( tokenHash === 0 ) { break; }
-        tokenOffset = tokenHashes[i++];
+        let tokenOffset = tokenHashes[i++];
         f = bucket.get(tokenHash);
         if ( f !== undefined && f.match(url, tokenOffset) === true ) {
             this.thRegister = tokenHash;
@@ -2437,8 +2445,10 @@ FilterContainer.prototype.matchStringGenericHide = function(requestURL) {
     let url = this.urlTokenizer.setURL(requestURL);
 
     // https://github.com/gorhill/uBlock/issues/2225
-    //   Important: this is used by FilterHostnameDict.match().
+    //   Important:
-    requestHostnameRegister = µb.URI.hostnameFromURI(url);
+    //   - `pageHostnameRegister` is used by FilterOrigin.matchOrigin().
+    //   - `requestHostnameRegister` is used by FilterHostnameDict.match().
+    pageHostnameRegister = requestHostnameRegister = µb.URI.hostnameFromURI(url);
 
     let bucket = this.categories.get(genericHideException);
     if ( !bucket || this.matchTokens(bucket, url) === false ) {
@@ -2548,7 +2558,7 @@ FilterContainer.prototype.matchString = function(context) {
     // https://github.com/chrisaljoudi/uBlock/issues/519
     // Use exact type match for anything beyond `other`
     // Also, be prepared to support unknown types
-    var type = typeNameToTypeValue[context.requestType];
+    let type = typeNameToTypeValue[context.requestType];
     if ( type === undefined ) {
          type = otherTypeBitValue;
     } else if ( type === 0 || type > otherTypeBitValue ) {
@@ -2577,7 +2587,7 @@ FilterContainer.prototype.matchString = function(context) {
     // filter.
 
     // Prime tokenizer: we get a normalized URL in return.
-    var url = this.urlTokenizer.setURL(context.requestURL);
+    let url = this.urlTokenizer.setURL(context.requestURL);
 
     // These registers will be used by various filters
     pageHostnameRegister = context.pageHostname || '';
@@ -2585,10 +2595,10 @@ FilterContainer.prototype.matchString = function(context) {
 
     this.fRegister = null;
 
-    var party = isFirstParty(context.pageDomain, context.requestHostname)
+    let party = isFirstParty(context.pageDomain, context.requestHostname)
         ? FirstParty
         : ThirdParty;
-    var categories = this.categories,
+    let categories = this.categories,
         catBits, bucket;
 
     // https://github.com/chrisaljoudi/uBlock/issues/139

src/js/storage.js

@@ -604,9 +604,7 @@
 
 µBlock.loadFilterLists = function(callback) {
     // Callers are expected to check this first.
-    if ( this.loadingFilterLists ) {
+    if ( this.loadingFilterLists ) { return; }
-        return;
-    }
     this.loadingFilterLists = true;
 
     var µb = this,
@@ -961,38 +959,31 @@
 
 /******************************************************************************/
 
-µBlock.loadPublicSuffixList = function(callback) {
+µBlock.loadPublicSuffixList = function() {
-    var µb = this,
+    return new Promise(resolve => {
-        assetKey = µb.pslAssetKey,
+    // start of executor
-        compiledAssetKey = 'compiled/' + assetKey;
+    this.assets.get('compiled/' + this.pslAssetKey, details => {
-
+        let selfie;
-    if ( typeof callback !== 'function' ) {
-        callback = this.noopFunc;
-    }
-    var onRawListLoaded = function(details) {
-        if ( details.content !== '' ) {
-            µb.compilePublicSuffixList(details.content);
-        }
-        callback();
-    };
-
-    var onCompiledListLoaded = function(details) {
-        var selfie;
         try {
             selfie = JSON.parse(details.content);
         } catch (ex) {
         }
         if (
-            selfie === undefined ||
+            selfie instanceof Object &&
-            publicSuffixList.fromSelfie(selfie) === false
+            publicSuffixList.fromSelfie(selfie)
         ) {
-            µb.assets.get(assetKey, onRawListLoaded);
+            resolve();
             return;
         }
-        callback();
+        this.assets.get(this.pslAssetKey, details => {
-    };
+            if ( details.content !== '' ) {
-
+                this.compilePublicSuffixList(details.content);
-    this.assets.get(compiledAssetKey, onCompiledListLoaded);
+            }
+            resolve();
+        });
+    });
+    // end of executor
+    });
 };
 
 /******************************************************************************/

src/js/wasm/README.md

@@ -0,0 +1,24 @@
+### For code reviewers
+
+All `wasm` files in that directory where created by compiling the
+corresponding `wat` file using the command (using `hntrie.wat`/`hntrie.wasm`
+as example):
+
+    wat2wasm hntrie.wat -o hntrie.wasm
+
+Assuming:
+
+- The command is executed from within the present directory.
+
+### `wat2wasm` tool
+
+The `wat2wasm` tool can be downloaded from an official WebAssembly project:
+<https://github.com/WebAssembly/wabt/releases>.
+
+### `wat2wasm` tool online
+
+You can also use the following online `wat2wasm` tool:
+<https://webassembly.github.io/wabt/demo/wat2wasm/>.
+
+Just paste the whole content of the `wat` file to compile into the WAT pane.
+Click "Download" button to retrieve the resulting `wasm` file.

src/js/wasm/hntrie.wat

@@ -0,0 +1,200 @@
+;;
+;; uBlock Origin - a browser extension to block requests.
+;; Copyright (C) 2018-present Raymond Hill
+;;
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see {http://www.gnu.org/licenses/}.
+;;
+;; Home: https://github.com/gorhill/uBlock
+;; File: hntrie.wat
+;; Description: WebAssembly code used by src/js/hntrie.js
+;; How to compile: See README.md in this directory.
+
+(module
+;;
+;; module start
+;;
+
+;; (func $log (import "imports" "log") (param i32 i32 i32))
+
+(memory (import "imports" "memory") 1)
+
+;;
+;; Public functions
+;;
+
+;;
+;; unsigned int matches(offset)
+;;
+;; Test whether the currently set needle matches the trie at specified offset.
+;;
+;; Memory layout, byte offset:
+;;   0-254: encoded needle (ASCII)
+;; 255    : needle length
+;; 256-   : tries
+;;
+(func (export "matches")
+    (param $itrie i32)
+    (result i32)                        ;; result: 0 = miss, 1 = hit
+    (local $ineedle i32)                ;; current needle offset
+    (local $nchar i32)                  ;; needle char being processed
+    (local $tchar i32)                  ;; trie char being processed
+    (local $lxtra i32)
+    (local $ixtra i32)
+    i32.const 255
+    i32.load8_u
+    set_local $ineedle
+    loop $nextNeedleChar
+        ;; ineedle -= 1;
+        get_local $ineedle
+        i32.const -1
+        i32.add
+        tee_local $ineedle
+        ;; let nchar = ineedle === -1 ? 0 : buf[ineedle];
+        i32.const 0
+        i32.lt_s
+        if
+            i32.const 0
+            set_local $nchar
+        else
+            get_local $ineedle
+            i32.load8_u
+            set_local $nchar
+        end
+        block $trieCharEqNeedleChar loop $nextTrieChar
+            ;; let tchar = buf[itrie+8];
+            get_local $itrie
+            i32.load8_u offset=8
+            tee_local $tchar
+            ;; if ( tchar === nchar ) { break; }
+            get_local $nchar
+            i32.eq
+            br_if $trieCharEqNeedleChar
+            ;; if ( tchar === 0 && nchar === 0x2E ) { return 1; }
+            get_local $tchar
+            i32.eqz
+            if
+                get_local $nchar
+                i32.const 0x2E
+                i32.eq
+                if
+                    i32.const 1
+                    return
+                end
+            end
+            ;; itrie = buf32[itrie >>> 2];
+            get_local $itrie
+            i32.load
+            tee_local $itrie
+            ;; if ( itrie === 0 ) { return 0; }
+            i32.eqz
+            if
+                i32.const 0
+                return
+            end
+            br $nextTrieChar
+        end end
+        ;; if ( nchar === 0 ) { return 1; }
+        get_local $nchar
+        i32.eqz
+        if
+            i32.const 1
+            return
+        end
+        ;; let lxtra = buf[itrie+9];
+        get_local $itrie
+        i32.load8_u offset=9
+        tee_local $lxtra
+        i32.eqz
+        if else
+            ;; if ( lxtra > ineedle ) { return 0; }
+            get_local $lxtra
+            get_local $ineedle
+            i32.gt_u
+            if
+                i32.const 0
+                return
+            end
+            ;; let ixtra = itrie + 10;
+            get_local $itrie
+            i32.const 10
+            i32.add
+            tee_local $ixtra
+            ;; lxtra += ixtra;
+            get_local $lxtra
+            i32.add
+            set_local $lxtra
+            ;; do {
+            block $noMoreExtraChars loop
+                ;; ineedle -= 1;
+                get_local $ineedle
+                i32.const -1
+                i32.add
+                tee_local $ineedle
+                ;; if ( buf[ineedle] !== buf[ixtra] ) { return 0; }
+                i32.load8_u
+                get_local $ixtra
+                i32.load8_u
+                i32.ne
+                if
+                    i32.const 0
+                    return
+                end
+                ;; ixtra += 1;
+                get_local $ixtra
+                i32.const 1
+                i32.add
+                tee_local $ixtra
+                ;; while ( ixtra !== lxtra ) {
+                get_local $lxtra
+                i32.eq
+                br_if $noMoreExtraChars
+                br 0
+            end end
+        end
+        ;; itrie = buf32[itrie + 4 >>> 2];
+        get_local $itrie
+        i32.load offset=4
+        tee_local $itrie
+        ;; if ( itrie === 0 ) {
+        i32.eqz
+        if
+            ;; return ineedle === 0 || buf[ineedle-1] === 0x2E ? 1 : 0;
+            get_local $ineedle
+            i32.eqz
+            if
+                i32.const 1
+                return
+            end
+            get_local $ineedle
+            i32.const -1
+            i32.add
+            i32.load8_u
+            i32.const 0x2E
+            i32.eq
+            if
+                i32.const 1
+                return
+            end
+            i32.const 0
+            return
+        end
+        br 0
+    end
+    i32.const 0
+)
+
+;;
+;; module end
+;;
+)