gecko/xpcom/tests/TestBloomFilter.cpp

121 lines
3.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/BloomFilter.h"
#include "TestHarness.h"
#include <stdio.h>
using namespace mozilla;
class FilterChecker {
public:
FilterChecker(uint32_t hash) :
mHash(hash)
{}
uint32_t hash() const { return mHash; }
private:
uint32_t mHash;
};
int main()
{
BloomFilter<12, FilterChecker> *filter = new BloomFilter<12, FilterChecker>();
FilterChecker one(1);
FilterChecker two(0x20000);
FilterChecker many(0x10000);
FilterChecker multiple(0x20001);
filter->add(&one);
if (!filter->mayContain(&one)) {
fail("Filter should contain 'one'");
return -1;
}
if (filter->mayContain(&multiple)) {
fail("Filter claims to contain 'multiple' when it should not");
return -1;
}
if (!filter->mayContain(&many)) {
fail("Filter should contain 'many' (false positive)");
return -1;
}
filter->add(&two);
if (!filter->mayContain(&multiple)) {
fail("Filter should contain 'multiple' (false positive)");
return -1;
}
// Test basic removals
filter->remove(&two);
if (filter->mayContain(&multiple)) {
fail("Filter claims to contain 'multiple' when it should not after two was "
"removed");
return -1;
}
// Test multiple addition/removal
const unsigned FILTER_SIZE = 255;
for (unsigned i = 0; i < FILTER_SIZE - 1; ++i) {
filter->add(&two);
}
if (!filter->mayContain(&multiple)) {
fail("Filter should contain 'multiple' after 'two' added lots of times "
"(false positive)");
return -1;
}
for (unsigned i = 0; i < FILTER_SIZE - 1; ++i) {
filter->remove(&two);
}
if (filter->mayContain(&multiple)) {
fail("Filter claims to contain 'multiple' when it should not after two was "
"removed lots of times");
return -1;
}
// Test overflowing the filter buckets
for (unsigned i = 0; i < FILTER_SIZE + 1; ++i) {
filter->add(&two);
}
if (!filter->mayContain(&multiple)) {
fail("Filter should contain 'multiple' after 'two' added lots more times "
"(false positive)");
return -1;
}
for (unsigned i = 0; i < FILTER_SIZE + 1; ++i) {
filter->remove(&two);
}
if (!filter->mayContain(&multiple)) {
fail("Filter claims to not contain 'multiple' even though we should have "
"run out of space in the buckets (false positive)");
return -1;
}
if (!filter->mayContain(&two)) {
fail("Filter claims to not contain 'two' even though we should have run "
"out of space in the buckets (false positive)");
return -1;
}
filter->remove(&one);
if (filter->mayContain(&one)) {
fail("Filter should not contain 'one', because we didn't overflow its "
"bucket");
return -1;
}
filter->clear();
if (filter->mayContain(&multiple)) {
fail("clear() failed to work");
return -1;
}
return 0;
}