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Chris Pilcher
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,76 +1,76 @@ | ||
| import XCTest | ||
|
|
||
| /* Two hash functions, adapted from | ||
| http://www.cse.yorku.ca/~oz/hash.html */ | ||
| http://www.cse.yorku.ca/~oz/hash.html */ | ||
|
|
||
| func djb2(x: String) -> Int { | ||
| var hash = 5381 | ||
| func djb2(_ x: String) -> Int { | ||
| var hash = 5381 | ||
|
|
||
| for char in x.characters { | ||
| hash = ((hash << 5) &+ hash) &+ char.hashValue | ||
| } | ||
| for char in x.characters { | ||
| hash = ((hash << 5) &+ hash) &+ char.hashValue | ||
| } | ||
|
|
||
| return Int(hash) | ||
| return Int(hash) | ||
| } | ||
|
|
||
| func sdbm(x: String) -> Int { | ||
| var hash = 0 | ||
| func sdbm(_ x: String) -> Int { | ||
| var hash = 0 | ||
|
|
||
| for char in x.characters { | ||
| hash = char.hashValue &+ (hash << 6) &+ (hash << 16) &- hash | ||
| } | ||
| for char in x.characters { | ||
| hash = char.hashValue &+ (hash << 6) &+ (hash << 16) &- hash | ||
| } | ||
|
|
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| return Int(hash) | ||
| return Int(hash) | ||
| } | ||
|
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|
|
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| class BloomFilterTests: XCTestCase { | ||
|
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| func testSingleHashFunction() { | ||
| let bloom = BloomFilter<String>(hashFunctions: [djb2]) | ||
| func testSingleHashFunction() { | ||
| let bloom = BloomFilter<String>(hashFunctions: [djb2]) | ||
|
|
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| bloom.insert("Hello world!") | ||
| bloom.insert("Hello world!") | ||
|
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| let result_good = bloom.query("Hello world!") | ||
| let result_bad = bloom.query("Hello world") | ||
| let result_good = bloom.query("Hello world!") | ||
| let result_bad = bloom.query("Hello world") | ||
|
|
||
| XCTAssertTrue(result_good) | ||
| XCTAssertFalse(result_bad) | ||
| } | ||
| XCTAssertTrue(result_good) | ||
| XCTAssertFalse(result_bad) | ||
| } | ||
|
|
||
| func testEmptyFilter() { | ||
| let bloom = BloomFilter<String>(hashFunctions: [djb2]) | ||
| func testEmptyFilter() { | ||
| let bloom = BloomFilter<String>(hashFunctions: [djb2]) | ||
|
|
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| let empty = bloom.isEmpty() | ||
| let empty = bloom.isEmpty() | ||
|
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| XCTAssertTrue(empty) | ||
| } | ||
| XCTAssertTrue(empty) | ||
| } | ||
|
|
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| func testMultipleHashFunctions() { | ||
| let bloom = BloomFilter<String>(hashFunctions: [djb2, sdbm]) | ||
| func testMultipleHashFunctions() { | ||
| let bloom = BloomFilter<String>(hashFunctions: [djb2, sdbm]) | ||
|
|
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| bloom.insert("Hello world!") | ||
| bloom.insert("Hello world!") | ||
|
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||
| let result_good = bloom.query("Hello world!") | ||
| let result_bad = bloom.query("Hello world") | ||
| let result_good = bloom.query("Hello world!") | ||
| let result_bad = bloom.query("Hello world") | ||
|
|
||
| XCTAssertTrue(result_good) | ||
| XCTAssertFalse(result_bad) | ||
| } | ||
| XCTAssertTrue(result_good) | ||
| XCTAssertFalse(result_bad) | ||
| } | ||
|
|
||
| func testFalsePositive() { | ||
| let bloom = BloomFilter<String>(size: 5, hashFunctions: [djb2, sdbm]) | ||
| func testFalsePositive() { | ||
| let bloom = BloomFilter<String>(size: 5, hashFunctions: [djb2, sdbm]) | ||
|
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| bloom.insert(["hello", "elloh", "llohe", "lohel", "ohell"]) | ||
| bloom.insert(["hello", "elloh", "llohe", "lohel", "ohell"]) | ||
|
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| print("Inserted") | ||
| print("Inserted") | ||
|
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| let query = bloom.query("This wasn't inserted!") | ||
| let query = bloom.query("This wasn't inserted!") | ||
|
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| // This is true even though we did not insert the value in the Bloom filter; | ||
| // the Bloom filter is capable of producing false positives but NOT | ||
| // false negatives. | ||
| // This is true even though we did not insert the value in the Bloom filter; | ||
| // the Bloom filter is capable of producing false positives but NOT | ||
| // false negatives. | ||
|
|
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| XCTAssertTrue(query) | ||
| } | ||
| XCTAssertTrue(query) | ||
| } | ||
| } |
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2 changes: 1 addition & 1 deletion
2
Bloom Filter/Tests/Tests.xcodeproj/xcshareddata/xcschemes/Tests.xcscheme
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