public HashSet <long> get_near_dups(Simhash simhash)
{
/*
* "simhash" is an instance of Simhash
* return a list of obj_id, which is in type of long (for now)
*/
if (simhash.fpSize != this.fpSize)
{
throw new Exception();
}
var ans = new HashSet <long>();
foreach (string key in get_keys(simhash))
{
if (bucket.ContainsKey(key))
{
var dups = bucket[key];
foreach (var dup in dups)
{
string[] parts = dup.Split(',');
ulong fp = Convert.ToUInt64(parts[0]);
long obj_id = Convert.ToInt64(parts[1]);
var sim2 = new Simhash(fp);
int d = simhash.distance(sim2);
if (d <= kDistance)
{
ans.Add(obj_id);
}
}
}
}
return(ans);
}
public HashSet<long> get_near_dups(Simhash simhash)
{
/*
"simhash" is an instance of Simhash
return a list of obj_id, which is in type of long (for now)
*/
if (simhash.fpSize != this.fpSize) throw new Exception();
var ans = new HashSet<long>();
foreach (string key in get_keys(simhash))
{
if (bucket.ContainsKey(key))
{
var dups = bucket[key];
foreach (var dup in dups)
{
string[] parts = dup.Split(',');
ulong fp = Convert.ToUInt64(parts[0]);
long obj_id = Convert.ToInt64(parts[1]);
var sim2 = new Simhash(fp);
int d = simhash.distance(sim2);
if (d <= kDistance)
{
ans.Add(obj_id);
}
}
}
}
return ans;
}
public void test_gethashcode_specialhashing_to64bit()
{
string eval = "aaa";
var simHash = new Simhash();
ulong fromDb = simHash.hashfuncjenkins(eval);
Assert.AreEqual(18323053351575752945, fromDb);
}
public void test_get_near_dup_hash()
{
var s1 = new Simhash(hashingType: Simhash.HashingType.MD5);
s1.GenerateSimhash("How are you i am fine.ablar ablar xyz blar blar blar blar blar blar blar thank");
var dups = index.get_near_dups(s1);
Assert.AreEqual(3, dups.Count);
var s2 = new Simhash(hashingType: Simhash.HashingType.MD5);
s2.GenerateSimhash(testData[1]);
index.delete(1, s2);
dups = index.get_near_dups(s1);
Assert.AreEqual(2, dups.Count);
var s3 = new Simhash(hashingType: Simhash.HashingType.MD5);
s3.GenerateSimhash(testData[1]);
index.delete(1, s3);
dups = index.get_near_dups(s1);
Assert.AreEqual(2, dups.Count);
var s4 = new Simhash(hashingType: Simhash.HashingType.MD5);
s4.GenerateSimhash(testData[1]);
index.add(1, s4);
dups = index.get_near_dups(s1);
Assert.AreEqual(3, dups.Count);
var s5 = new Simhash(hashingType: Simhash.HashingType.MD5);
s5.GenerateSimhash(testData[1]);
index.add(1, s5);
dups = index.get_near_dups(s1);
Assert.AreEqual(3, dups.Count);
}
public void test_get_keys()
{
Dictionary<long, string> testdata = new Dictionary<long, string>();
testdata.Add(1, "How are you? I Am fine. blar blar blar blar blar Thanks.");
Dictionary<long, Simhash> simHashObjs = new Dictionary<long, Simhash>();
foreach (var it in testdata)
{
var simHash = new Simhash(hashingType:Simhash.HashingType.MD5);
simHash.GenerateSimhash(it.Value);
simHashObjs.Add(it.Key, simHash);
}
var simHashIndex = new SimhashIndex(objs: simHashObjs, k: 10);
var listOfKeys = simHashIndex.get_the_keys(simHashObjs[1]);
Assert.IsTrue(listOfKeys.Count == 11);
Assert.AreEqual("26,0", listOfKeys[0]);
Assert.AreEqual("3,1", listOfKeys[1]);
Assert.AreEqual("7,2", listOfKeys[2]);
Assert.AreEqual("12,3", listOfKeys[3]);
Assert.AreEqual("17,4", listOfKeys[4]);
Assert.AreEqual("0,5", listOfKeys[5]);
Assert.AreEqual("13,6", listOfKeys[6]);
Assert.AreEqual("30,7", listOfKeys[7]);
Assert.AreEqual("1,8", listOfKeys[8]);
Assert.AreEqual("14,9", listOfKeys[9]);
Assert.AreEqual("7496,10", listOfKeys[10]);
}
public void Get_Keys()
{
var simhash = new SimhashLib.Simhash();
var testdata = new Dictionary <long, string>();
testdata.Add(1, "How are you? I Am fine. blar blar blar blar blar Thanks.");
var simHashObjs = new Dictionary <long, SimhashResult>();
foreach (var it in testdata)
{
simHashObjs.Add(it.Key, simhash.ComputeHashByMd5(it.Value));
}
var simHashIndex = new SimhashIndex(objs: simHashObjs, k: 10);
var listOfKeys = simHashIndex.GetListKeys(simHashObjs[1]);
Assert.True(listOfKeys.Count == 11);
Assert.Equal("26,0", listOfKeys[0]);
Assert.Equal("3,1", listOfKeys[1]);
Assert.Equal("7,2", listOfKeys[2]);
Assert.Equal("12,3", listOfKeys[3]);
Assert.Equal("17,4", listOfKeys[4]);
Assert.Equal("0,5", listOfKeys[5]);
Assert.Equal("13,6", listOfKeys[6]);
Assert.Equal("30,7", listOfKeys[7]);
Assert.Equal("1,8", listOfKeys[8]);
Assert.Equal("14,9", listOfKeys[9]);
Assert.Equal("7496,10", listOfKeys[10]);
}
public void test_hashstringtobigint()
{
var simHash = new Simhash();
BigInteger actualBiggie = simHash.hashfunc_hashstringtobignasty("47bce5c74f589f4867dbd57e9ca9f808");
string expectedBiggie = "95355999972893604581396806948474189832";
Assert.AreEqual(expectedBiggie, actualBiggie.ToString());
}
public void Get_Near_Dup_Hash()
{
var simhash = new SimhashLib.Simhash();
var hash = simhash.ComputeHashByMd5("How are you i am fine.ablar ablar xyz blar blar blar blar blar blar blar thank");
var dups = index.GetNearDups(hash);
Assert.Equal(3, dups.Count);
var hash2 = simhash.ComputeHashByMd5(testData[1]);
index.Delete(1, hash2);
dups = index.GetNearDups(hash);
Assert.Equal(2, dups.Count);
var hash3 = simhash.ComputeHashByMd5(testData[1]);
index.Delete(1, hash3);
dups = index.GetNearDups(hash);
Assert.Equal(2, dups.Count);
var hash4 = simhash.ComputeHashByMd5(testData[1]);
index.Add(1, hash4);
dups = index.GetNearDups(hash);
Assert.Equal(3, dups.Count);
var hash5 = simhash.ComputeHashByMd5(testData[1]);
index.Add(1, hash5);
dups = index.GetNearDups(hash);
Assert.Equal(3, dups.Count);
}
public void test_value()
{
List<string> features = new List<string>() { "aaa", "bbb" };
var simHash = new Simhash(hashingType:Simhash.HashingType.MD5);
simHash.GenerateSimhash(features);
ulong expected = 8637903533912358349;
Assert.AreEqual(expected, simHash.value);
}
public void test_get_near_dup_hash_jenkins_not_close()
{
var index = setUpIndex(1);
var s = new Simhash();
s.GenerateSimhash("This is not even close to the text that is loaded by default");
var dups = index.get_near_dups(s);
Assert.AreEqual(0, dups.Count);
}
private static SimhashResult ComputeHash <THash, TRes>(this Simhash self, string content, THash hash)
where THash : struct, IHash <TRes>
where TRes : IHashResult <TRes>
{
var builder = new StringBuilder(content.Length);
var shingles = Shingling.Tokenize(content, builder);
return(self.ComputeHash <THash, TRes>(shingles, hash));
}
public void Get_Near_Dup_Hash_Jenkins_Not_Close()
{
var simhash = new SimhashLib.Simhash();
var index = SetUpIndex(1);
var hash = simhash.ComputeHashByMd5("This is not even close to the text that is loaded by default");
var dups = index.GetNearDups(hash);
Assert.Empty(dups);
}
public void delete(long obj_id, Simhash simhash)
{
foreach (string key in get_keys(simhash))
{
string v = string.Format("{0},{1}", simhash.value, obj_id);
if (bucket.ContainsKey(key))
{
bucket[key].Remove(v);
}
}
}
public void delete(long obj_id, Simhash simhash)
{
foreach (string key in get_keys(simhash))
{
string v = string.Format("{0},{1}", simhash.value, obj_id);
if (bucket.ContainsKey(key))
{
bucket[key].Remove(v);
}
}
}
public void test_get_near_dup_hash_jenkins_find_one()
{
var index = setUpIndex(1);
var s = new Simhash();
var shingling = new Shingling();
var features = shingling.tokenize(testData[1], 3);
s.GenerateSimhash(features);
var dups = index.get_near_dups(s);
Assert.AreEqual(1, dups.Count);
}
public int distance(Simhash another)
{
if (fpSize != another.fpSize) throw new Exception();
ulong x = (value ^ another.value) & (ulong.MaxValue);
int ans = 0;
while (x > 0)
{
ans++;
x &= x - 1;
}
return ans;
}
public void Get_Near_Dup_Hash_Jenkins_Find_One()
{
var simhash = new SimhashLib.Simhash();
var index = SetUpIndex(1);
var features = Shingling.Tokenize(testData[1], new StringBuilder(), 3);
var hash = simhash.ComputeHashByMd5(features);
var dups = index.GetNearDups(hash);
Assert.Single(dups);
}
public TestSimhashIndexMD5()
{
var simhash = new SimhashLib.Simhash();
testData.Add(1, "How are you? I Am fine. blar blar blar blar blar Thanks.");
testData.Add(2, "How are you i am fine. blar blar blar blar blar than");
testData.Add(3, "This is simhash test.");
testData.Add(4, "How are you i am fine. blar blar blar blar blar thank1");
foreach (var it in testData)
{
objs.Add(it.Key, simhash.ComputeHashByMd5(it.Value));
}
index = new SimhashIndex(objs: objs, k: 10);
}
private SimhashIndex setUpIndex(int kValue)
{
Dictionary<long, Simhash> objs = new Dictionary<long, Simhash>();
foreach (var it in testData)
{
var simHash = new Simhash();
var shingling = new Shingling();
var features = shingling.tokenize(it.Value, 3);
simHash.GenerateSimhash(features);
objs.Add(it.Key, simHash);
}
return new SimhashIndex(objs: objs, k: kValue);
}
private SimhashIndex SetUpIndex(int kValue)
{
var simhash = new SimhashLib.Simhash();
var objs = new Dictionary <long, SimhashResult>();
var builder = new StringBuilder();
foreach (var it in testData)
{
var features = Shingling.Tokenize(it.Value, builder.Clear(), 3);
objs.Add(it.Key, simhash.ComputeHashByMd5(features));
}
return(new SimhashIndex(objs: objs, k: kValue));
}
public void setUp()
{
testData.Add(1, "How are you? I Am fine. blar blar blar blar blar Thanks.");
testData.Add(2, "How are you i am fine. blar blar blar blar blar than");
testData.Add(3, "This is simhash test.");
testData.Add(4, "How are you i am fine. blar blar blar blar blar thank1");
foreach(var it in testData)
{
var simHash = new Simhash(hashingType:Simhash.HashingType.MD5);
simHash.GenerateSimhash(it.Value);
objs.Add(it.Key, simHash);
}
index = new SimhashIndex(objs: objs, k: 10);
}
public int distance(Simhash another)
{
if (fpSize != another.fpSize)
{
throw new Exception();
}
ulong x = (value ^ another.value) & (ulong.MaxValue);
int ans = 0;
while (x > 0)
{
ans++;
x &= x - 1;
}
return(ans);
}
public void test_distance()
{
var sh = new Simhash();
sh.GenerateSimhash("How are you? I AM fine. Thanks. And you?");
var sh2 = new Simhash();
sh2.GenerateSimhash("How old are you? :-) i am fine. Thanks. And you?");
int distA = sh.distance(sh2);
Assert.IsTrue(distA > 0);
var sh3 = new Simhash(sh2);
int distB = sh2.distance(sh3);
Assert.AreEqual(0,distB);
var sh4 = new Simhash();
sh4.GenerateSimhash("1");
Assert.AreNotEqual(0, sh4.distance(sh3));
}
public void add(long obj_id, Simhash simhash)
{
foreach (string key in get_keys(simhash))
{
string v = string.Format("{0},{1}", simhash.value, obj_id);
if (!bucket.ContainsKey(key))
{
var bucketHashSet = new HashSet<string>() { v };
bucket.Add(key, bucketHashSet);
}
else
{
var values = bucket[key];
values.Add(v);
}
}
}
public void test_chinese()
{
var sh = new Simhash();
sh.GenerateSimhash("你好 世界！ 呼噜。");
var sh2 = new Simhash();
sh2.GenerateSimhash("你好，世界呼噜");
Assert.AreEqual(sh.distance(sh2), 0);
var sh4 = new Simhash();
sh4.GenerateSimhash("How are you? I Am fine. ablar ablar xyz blar blar blar blar blar blar blar Thanks.");
var sh5 = new Simhash();
sh5.GenerateSimhash("How are you i am fine.ablar ablar xyz blar blar blar blar blar blar blar than");
var sh6 = new Simhash();
sh6.GenerateSimhash("How are you i am fine.ablar ablar xyz blar blar blar blar blar blar blar thank");
Assert.IsTrue(sh4.distance(sh6) < 3);
Assert.IsTrue(sh5.distance(sh6) < 3);
}
private void Chinese <THash, TRes>(THash hash)
where THash : IHash <TRes>
where TRes : IHashResult <TRes>
{
var simhash = new SimhashLib.Simhash();
var h1 = simhash.ComputeHash <THash, TRes>("你好 世界！ 呼噜。", hash);
var h2 = simhash.ComputeHash <THash, TRes>("你好，世界呼噜", hash);
Assert.Equal(0, h1.Distance(h2));
var h4 = simhash.ComputeHash <THash, TRes>("How are you? I Am fine. ablar ablar xyz blar blar blar blar blar blar blar Thanks.", hash);
var h5 = simhash.ComputeHash <THash, TRes>("How are you i am fine.ablar ablar xyz blar blar blar blar blar blar blar than", hash);
var h6 = simhash.ComputeHash <THash, TRes>("How are you i am fine.ablar ablar xyz blar blar blar blar blar blar blar thank", hash);
Assert.True(h4.Distance(h6) < 3);
Assert.True(h5.Distance(h6) < 3);
}
public void add(long obj_id, Simhash simhash)
{
foreach (string key in get_keys(simhash))
{
string v = string.Format("{0},{1}", simhash.value, obj_id);
if (!bucket.ContainsKey(key))
{
var bucketHashSet = new HashSet <string>()
{
v
};
bucket.Add(key, bucketHashSet);
}
else
{
var values = bucket[key];
values.Add(v);
}
}
}
private void Short <THash, TRes>(THash hash)
where THash : IHash <TRes>
where TRes : IHashResult <TRes>
{
var simhash = new SimhashLib.Simhash();
var ss = new List <string>()
{
"aa", "aaa", "aaaa", "aaaab", "aaaaabb", "aaaaabbb"
};
var shs = ss.Select(s => simhash.ComputeHash <THash, TRes>(s, hash)).ToList();
foreach (var sh1 in shs)
{
foreach (var sh2 in shs.Where(sh2 => !sh1.Equals(sh2)))
{
Assert.NotEqual(sh1, sh2);
}
}
}
public void test_short()
{
List<Simhash> shs = new List<Simhash>();
List<string> ss = new List<string>() { "aa", "aaa", "aaaa", "aaaab", "aaaaabb", "aaaaabbb" };
foreach (string s in ss)
{
var simHash = new Simhash();
simHash.GenerateSimhash(s);
shs.Add(simHash);
}
foreach (Simhash sh1 in shs)
{
foreach (Simhash sh2 in shs)
{
if (sh1 != sh2)
{
Assert.AreNotEqual(sh1, sh2);
}
}
}
}
private static IEnumerable <string> get_keys(Simhash simhash)
{
for (int i = 0; i < offsets.Count; i++)
{
int off;
if (i == (offsets.Count - 1))
{
off = (fpSizeStatic - offsets[i]);
}
else
{
off = offsets[i + 1] - offsets[i];
}
double m = (Math.Pow(2, off)) - 1;
ulong m64 = Convert.ToUInt64(m);
ulong offset64 = Convert.ToUInt64(offsets[i]);
ulong c = simhash.value >> offsets[i] & m64;
yield return(string.Format("{0},{1}", c, i));
}
}
public void Distance <THash, TRes>(THash hash)
where THash : IHash <TRes>
where TRes : IHashResult <TRes>
{
var simhash = new SimhashLib.Simhash();
var hash1 = simhash.ComputeHash <THash, TRes>("How are you? I AM fine. Thanks. And you?", hash);
var hash2 = simhash.ComputeHash <THash, TRes>("How old are you? :-) i am fine. Thanks. And you?", hash);
var distA = hash1.Distance(hash2);
var dist2 = hash1.Distance(hash2);
Assert.True(distA > 0);
Assert.True(dist2 > 0);
var distB = hash2.Distance(hash2);
var dist3 = hash2.Distance(hash2);
Assert.Equal(0, distB);
Assert.Equal(0, dist3);
var hash3 = simhash.ComputeHash <THash, TRes>("1", hash);
Assert.NotEqual(0, hash3.Distance(hash2));
}
public static SimhashResult ComputeHashByMd5(this Simhash self, List <string> tokens) => self.ComputeHash <Md5Hash, Md5HashResult>(tokens, new Md5Hash());
public static SimhashResult ComputeHashByMurmurHash3(this Simhash self, List <string> tokens) => self.ComputeHash <MurmurHash3, MurmurHash3Result>(tokens, new MurmurHash3());
public static SimhashResult ComputeHashByJenkins(this Simhash self, string content, uint seed = default) => self.ComputeHash <JenkinsHash, JenkinsHashResult>(content, new JenkinsHash(seed));
public static SimhashResult ComputeHashByMurmurHash3(this Simhash self, string content) => self.ComputeHash <MurmurHash3, MurmurHash3Result>(content, new MurmurHash3());
public Simhash(Simhash simHash)
{
value = simHash.value;
}
public static SimhashResult ComputeHashByJenkins(this Simhash self, List <string> tokens, uint seed = default) => self.ComputeHash <JenkinsHash, JenkinsHashResult>(tokens, new JenkinsHash(seed));
public static SimhashResult ComputeHashByMd5(this Simhash self, string content) => self.ComputeHash <Md5Hash, Md5HashResult>(content, new Md5Hash());
private static IEnumerable<string> get_keys(Simhash simhash)
{
for (int i = 0; i < offsets.Count; i++)
{
int off;
if (i == (offsets.Count - 1))
{
off = (fpSizeStatic - offsets[i]);
}
else
{
off = offsets[i + 1] - offsets[i];
}
double m = (Math.Pow(2, off)) - 1;
ulong m64 = Convert.ToUInt64(m);
ulong offset64 = Convert.ToUInt64(offsets[i]);
ulong c = simhash.value >> offsets[i] & m64;
yield return string.Format("{0},{1}", c, i);
}
}
public void test_hashtostringvalue()
{
var simHash = new Simhash();
string val = simHash.hashfunc_hashtostring("aaa");
Assert.AreEqual(val, "47bce5c74f589f4867dbd57e9ca9f808");
}
public Simhash(Simhash simHash)
{
value = simHash.value;
}
public void test_value_control()
{
List<string> features = new List<string>() { "aaa" };
var simHash = new Simhash(hashingType:Simhash.HashingType.MD5);
simHash.GenerateSimhash(features);
ulong expected = 7483809945577191432;
Assert.AreEqual(expected, simHash.value);
}
public List <string> get_the_keys(Simhash simhash)
{
return(get_keys(simhash).ToList());
}
public void test_value_by_string()
{
var simHash = new Simhash(hashingType:Simhash.HashingType.MD5);
simHash.GenerateSimhash("aaa bbb test test testing.happy time = -).");
ulong expected = 5683413558821905382;
Assert.AreEqual(expected, simHash.value);
}
public List<string> get_the_keys(Simhash simhash)
{
return get_keys(simhash).ToList();
}