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bloom.js
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bloom.js
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var JSBloom = {};
JSBloom.filter = function(items, target_prob) {
if (typeof items !== "number" || typeof target_prob !== "number" || target_prob >= 1) {
throw Error("Usage: new JSBloom.filter(items, target_probability)");
};
var BUFFER_LEN = (function() {
var buffer = Math.ceil((items * Math.log(target_prob)) / Math.log(1.0 / (Math.pow(2.0, Math.log(2.0)))));
if ((buffer % 8) !== 0) {
buffer += 8 - (buffer % 8);
};
return buffer;
})(),
HASH_ROUNDS = Math.round(Math.log(2.0) * BUFFER_LEN / items),
LZString = function(){function o(o,r){if(!t[o]){t[o]={};for(var n=0;n<o.length;n++)t[o][o.charAt(n)]=n}return t[o][r]}var r=String.fromCharCode,n="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",e="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-$",t={},i={compressToBase64:function(o){if(null==o)return"";var r=i._compress(o,6,function(o){return n.charAt(o)});switch(r.length%4){default:case 0:return r;case 1:return r+"===";case 2:return r+"==";case 3:return r+"="}},decompressFromBase64:function(r){return null==r?"":""==r?null:i._decompress(r.length,32,function(e){return o(n,r.charAt(e))})},compressToUTF16:function(o){return null==o?"":i._compress(o,15,function(o){return r(o+32)})+" "},decompressFromUTF16:function(o){return null==o?"":""==o?null:i._decompress(o.length,16384,function(r){return o.charCodeAt(r)-32})},compressToUint8Array:function(o){for(var r=i.compress(o),n=new Uint8Array(2*r.length),e=0,t=r.length;t>e;e++){var s=r.charCodeAt(e);n[2*e]=s>>>8,n[2*e+1]=s%256}return n},decompressFromUint8Array:function(o){if(null===o||void 0===o)return i.decompress(o);for(var n=new Array(o.length/2),e=0,t=n.length;t>e;e++)n[e]=256*o[2*e]+o[2*e+1];var s=[];return n.forEach(function(o){s.push(r(o))}),i.decompress(s.join(""))},compressToEncodedURIComponent:function(o){return null==o?"":i._compress(o,6,function(o){return e.charAt(o)})},decompressFromEncodedURIComponent:function(r){return null==r?"":""==r?null:(r=r.replace(/ /g,"+"),i._decompress(r.length,32,function(n){return o(e,r.charAt(n))}))},compress:function(o){return i._compress(o,16,function(o){return r(o)})},_compress:function(o,r,n){if(null==o)return"";var e,t,i,s={},p={},u="",c="",a="",l=2,f=3,h=2,d=[],m=0,v=0;for(i=0;i<o.length;i+=1)if(u=o.charAt(i),Object.prototype.hasOwnProperty.call(s,u)||(s[u]=f++,p[u]=!0),c=a+u,Object.prototype.hasOwnProperty.call(s,c))a=c;else{if(Object.prototype.hasOwnProperty.call(p,a)){if(a.charCodeAt(0)<256){for(e=0;h>e;e++)m<<=1,v==r-1?(v=0,d.push(n(m)),m=0):v++;for(t=a.charCodeAt(0),e=0;8>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1}else{for(t=1,e=0;h>e;e++)m=m<<1|t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t=0;for(t=a.charCodeAt(0),e=0;16>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1}l--,0==l&&(l=Math.pow(2,h),h++),delete p[a]}else for(t=s[a],e=0;h>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1;l--,0==l&&(l=Math.pow(2,h),h++),s[c]=f++,a=String(u)}if(""!==a){if(Object.prototype.hasOwnProperty.call(p,a)){if(a.charCodeAt(0)<256){for(e=0;h>e;e++)m<<=1,v==r-1?(v=0,d.push(n(m)),m=0):v++;for(t=a.charCodeAt(0),e=0;8>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1}else{for(t=1,e=0;h>e;e++)m=m<<1|t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t=0;for(t=a.charCodeAt(0),e=0;16>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1}l--,0==l&&(l=Math.pow(2,h),h++),delete p[a]}else for(t=s[a],e=0;h>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1;l--,0==l&&(l=Math.pow(2,h),h++)}for(t=2,e=0;h>e;e++)m=m<<1|1&t,v==r-1?(v=0,d.push(n(m)),m=0):v++,t>>=1;for(;;){if(m<<=1,v==r-1){d.push(n(m));break}v++}return d.join("")},decompress:function(o){return null==o?"":""==o?null:i._decompress(o.length,32768,function(r){return o.charCodeAt(r)})},_decompress:function(o,n,e){var t,i,s,p,u,c,a,l,f=[],h=4,d=4,m=3,v="",w=[],A={val:e(0),position:n,index:1};for(i=0;3>i;i+=1)f[i]=i;for(p=0,c=Math.pow(2,2),a=1;a!=c;)u=A.val&A.position,A.position>>=1,0==A.position&&(A.position=n,A.val=e(A.index++)),p|=(u>0?1:0)*a,a<<=1;switch(t=p){case 0:for(p=0,c=Math.pow(2,8),a=1;a!=c;)u=A.val&A.position,A.position>>=1,0==A.position&&(A.position=n,A.val=e(A.index++)),p|=(u>0?1:0)*a,a<<=1;l=r(p);break;case 1:for(p=0,c=Math.pow(2,16),a=1;a!=c;)u=A.val&A.position,A.position>>=1,0==A.position&&(A.position=n,A.val=e(A.index++)),p|=(u>0?1:0)*a,a<<=1;l=r(p);break;case 2:return""}for(f[3]=l,s=l,w.push(l);;){if(A.index>o)return"";for(p=0,c=Math.pow(2,m),a=1;a!=c;)u=A.val&A.position,A.position>>=1,0==A.position&&(A.position=n,A.val=e(A.index++)),p|=(u>0?1:0)*a,a<<=1;switch(l=p){case 0:for(p=0,c=Math.pow(2,8),a=1;a!=c;)u=A.val&A.position,A.position>>=1,0==A.position&&(A.position=n,A.val=e(A.index++)),p|=(u>0?1:0)*a,a<<=1;f[d++]=r(p),l=d-1,h--;break;case 1:for(p=0,c=Math.pow(2,16),a=1;a!=c;)u=A.val&A.position,A.position>>=1,0==A.position&&(A.position=n,A.val=e(A.index++)),p|=(u>0?1:0)*a,a<<=1;f[d++]=r(p),l=d-1,h--;break;case 2:return w.join("")}if(0==h&&(h=Math.pow(2,m),m++),f[l])v=f[l];else{if(l!==d)return null;v=s+s.charAt(0)}w.push(v),f[d++]=s+v.charAt(0),h--,s=v,0==h&&(h=Math.pow(2,m),m++)}}};return i}();"function"==typeof define&&define.amd?define(function(){return LZString}):"undefined"!=typeof module&&null!=module&&(module.exports=LZString),
bVector = new Uint8Array(BUFFER_LEN/8);
hashes = {
djb2: function(str) {
var hash = 5381;
for (var len = str.length, count = 0; count < len; count++) {
hash = hash * 33 ^ str.charCodeAt(count);
};
return (hash >>> 0) % BUFFER_LEN;
},
sdbm: function(str) {
var hash = 0;
for (var len = str.length, count = 0; count < len; count++) {
hash = str.charCodeAt(count) + (hash << 6) + (hash << 16) - hash;
};
return (hash >>> 0) % BUFFER_LEN;
}
}
addEntry = function(str) {
var h1 = hashes.djb2(str)
var h2 = hashes.sdbm(str)
var added = false
for (var round = 0; round <= HASH_ROUNDS; round++) {
var new_hash = round == 0 ? h1
: round == 1 ? h2
: (h1 + (round * h2) + (round^2)) % BUFFER_LEN;
var extra_indices = new_hash % 8,
index = ((new_hash - extra_indices) / 8);
if (extra_indices != 0 && (bVector[index] & (128 >> (extra_indices - 1))) == 0) {
bVector[index] ^= (128 >> extra_indices - 1);
added = true;
} else if (extra_indices == 0 && (bVector[index] & 1) == 0) {
bVector[index] ^= 1;
added = true;
}
};
return added;
}
addEntries = function(arr) {
for (var i = arr.length - 1; i >= 0; i--) {
addEntry(arr[i]);
};
return true;
}
checkEntry = function(str) {
var index, extra_indices
var h1 = hashes.djb2(str)
extra_indices = h1 % 8;
index = ((h1 - extra_indices) / 8);
if (extra_indices != 0 && (bVector[index] & (128 >> (extra_indices - 1))) == 0) {
return false;
} else if (extra_indices == 0 && (bVector[index] & 1) == 0) {
return false;
}
var h2 = hashes.sdbm(str)
extra_indices = h2 % 8;
index = ((h2 - extra_indices) / 8);
if (extra_indices != 0 && (bVector[index] & (128 >> (extra_indices - 1))) == 0) {
return false;
} else if (extra_indices == 0 && (bVector[index] & 1) == 0) {
return false;
}
for (var round = 2; round <= HASH_ROUNDS; round++) {
var new_hash = round==0?h1:round==1?h2:(h1 + (round * h2) + (round^2)) % BUFFER_LEN;
var extra_indices = new_hash % 8,
index = ((new_hash - extra_indices) / 8);
if (extra_indices != 0 && (bVector[index] & (128 >> (extra_indices - 1))) == 0) {
return false;
} else if (extra_indices == 0 && (bVector[index] & 1) == 0) {
return false;
}
};
return true;
}
importData = function(lzData, k) {
var raw_data = LZString.decompressFromBase64(lzData),
data = raw_data.split(',');
BUFFER_LEN = data.length * 8;
HASH_ROUNDS = (typeof k !== "undefined") ? k : HASH_ROUNDS;
bVector = new Uint8Array(data)
}
exportData = function(callback) {
switch (typeof callback) {
case "function":
callback(LZString.compressToBase64(bVector.toString()));
break;
default:
return LZString.compressToBase64(bVector.toString());
}
}
return {
info: {
type: "regular",
buffer: BUFFER_LEN,
hashes: HASH_ROUNDS,
raw_buffer: bVector
},
hashes: hashes,
addEntry: addEntry,
addEntries: addEntries,
checkEntry: checkEntry,
importData: importData,
exportData: exportData
};
};
if (typeof exports !== "undefined") {
exports.filter = JSBloom.filter;
};