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use buffer for bloom filter.

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This commit is contained in:
Christopher Jeffrey 2016-02-23 02:56:21 -08:00
parent d63f4af6ca
commit 3514eb7dec
1 changed files with 7 additions and 20 deletions
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27
lib/bcoin/bloom.js
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@ -15,7 +15,7 @@ function Bloom(size, n, tweak) {
if (!(this instanceof Bloom))
return new Bloom(size, n, tweak);
this.filter = new Array(Math.ceil(size / 32));
this.filter = new Buffer(Math.ceil(size / 8));
this.size = size;
this.n = n;
this.tweak = tweak;
@ -28,8 +28,7 @@ Bloom.prototype.hash = function hash(val, n) {
};
Bloom.prototype.reset = function reset() {
for (var i = 0; i < this.filter.length; i++)
this.filter[i] = 0;
this.filter.fill(0);
};
Bloom.prototype.add = function add(val, enc) {
@ -41,8 +40,9 @@ Bloom.prototype.add = function add(val, enc) {
bit = this.hash(val, i);
pos = 1 << (bit & 0x1f);
shift = bit >> 5;
shift *= 4;
this.filter[shift] |= pos;
utils.writeU32(this.filter, utils.readU32(this.filter, shift) | pos, shift);
}
};
@ -55,8 +55,9 @@ Bloom.prototype.test = function test(val, enc) {
bit = this.hash(val, i);
pos = 1 << (bit & 0x1f);
shift = bit >> 5;
shift *= 4;
if ((this.filter[shift] & pos) === 0)
if ((utils.readU32(this.filter, shift) & pos) === 0)
return false;
}
@ -64,21 +65,7 @@ Bloom.prototype.test = function test(val, enc) {
};
Bloom.prototype.toBuffer = function toBuffer() {
var bytes = Math.ceil(this.size / 8);
var res = new Buffer(this.filter.length * 4);
var i, w;
res.fill(0);
for (i = 0; i < this.filter.length; i++) {
w = this.filter[i];
res[i * 4] = w & 0xff;
res[i * 4 + 1] = (w >> 8) & 0xff;
res[i * 4 + 2] = (w >> 16) & 0xff;
res[i * 4 + 3] = (w >> 24) & 0xff;
}
return res.slice(0, bytes);
return this.filter;
};
function mul32(a, b) {