public IEnumerable <object> GetPersonsByName(string firstpartofname)
{
firstpartofname = firstpartofname.ToLower();
PaEntry entry = tab_person.Element(0);
var query = index_person_name.GetAllByLevel(s =>
{
string ss = s.ToLower();
if (ss.StartsWith(firstpartofname))
{
return(0);
}
return(ss.CompareTo(firstpartofname));
});
return(query
.Select(ent =>
{
//long off = (long)ent.Get();
//entry.offset = off;
return entry.Get();
})
.Cast <object[]>()
.Where(pair => !((bool)pair[0]))
.Select(pair => pair[1]));
}
/// <summary>
/// Вызывает GetAllByLevel, отсеивает удалённые строки где row[0] = false и возвращает содержимое row[1].
/// </summary>
/// <typeparam name="Tkey"></typeparam>
/// <typeparam name="IndexImmut"></typeparam>
/// <param name="index"></param>
/// <param name="levelFunc">Функция применяется к содержимому таблицы row[1] </param>
/// <returns></returns>
public static IEnumerable <object[]> GetAllUndeletedByLevel <Tkey, IndexImmut>(
this IndexDynamic <Tkey, IndexImmut> index,
Func <object[], int> levelFunc)
where IndexImmut : IIndexImmutable <Tkey> =>
index.GetAllByLevel(ent => levelFunc(ent.Get().CastRow <object, object[]>().Item2))
.Select(ent => (object[])ent.Get())
.Where(row => !(bool)row[0])
.Select(row => (object[])row[1]);
public IEnumerable <object> GetTriplesBySubject(int subj)
{
var q = index_spo.GetAllByLevel((PaEntry ent) =>
{
object[] rec = (object[])((object[])((object[])ent.Get()))[1];
return(((int)rec[0]).CompareTo(subj));
}).Select(ent => ((object[])ent.Get())[1])
.ToArray();
return(q);
}
public static void Main4(string[] args)
{
Random rnd = new Random();
Console.WriteLine("Start Task04_Sequenses_Main3");
System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
PType tp_person = new PTypeRecord(
new NamedType("id", new PType(PTypeEnumeration.integer)),
new NamedType("name", new PType(PTypeEnumeration.sstring)),
new NamedType("age", new PType(PTypeEnumeration.real)));
TableView tab_person = new TableView(path + "tab_person.pac", tp_person);
IndexViewImmutable <string> name_index = new IndexViewImmutable <string>(path + "name_index.pac")
{
Table = tab_person,
KeyProducer = v => (string)((object[])((object[])v)[1])[1]
};
IndexDynamic <string, IndexViewImmutable <string> > index_person_name = new IndexDynamic <string, IndexViewImmutable <string> >(false, name_index);
tab_person.RegisterIndex(index_person_name);
int nelements = 1_000_000;
bool toload = true; // Загружать или нет новую базу данных
if (toload)
{
sw.Restart();
// Очистим ячейки последовательности и индекса
tab_person.Clear();
IEnumerable <object> flow = Enumerable.Range(0, nelements)
.Select(i =>
{
int id = nelements - i;
string name = "=" + id.ToString() + "=";
double age = rnd.NextDouble() * 100.0;
return(new object[] { id, name, age });
});
tab_person.Fill(flow);
// Теперь надо отсортировать индексный массив по ключу
tab_person.BuildIndexes();
sw.Stop();
Console.WriteLine("Load ok. duration for {0} elements: {1} ms", nelements, sw.ElapsedMilliseconds);
}
else
{
tab_person.Warmup();
}
// Проверим работу
int search_key = nelements * 2 / 3;
var ob = index_person_name.GetAllByKey("=" + search_key + "=")
.Select(ent => ((object[])ent.Get())[1])
.FirstOrDefault();
if (ob == null)
{
throw new Exception("Didn't find person " + search_key);
}
Console.WriteLine("Person {0} has name {1}", search_key, ((object[])ob)[1]);
// Засечем скорость выборок
int nprobe = 1000;
sw.Restart();
for (int i = 0; i < nprobe; i++)
{
search_key = rnd.Next(nelements) + 1;
ob = index_person_name.GetAllByKey("=" + search_key + "=")
.Select(ent => ((object[])ent.Get())[1])
.FirstOrDefault();
if (ob == null)
{
throw new Exception("Didn't find person " + search_key);
}
string nam = (string)((object[])ob)[1];
}
sw.Stop();
Console.WriteLine($"Duration for {nprobe} search in {nelements} elements: {sw.ElapsedMilliseconds} ms");
string search_string = "=66666";
var query = index_person_name.GetAllByLevel((PaEntry entry) =>
{
var name = (string)((object[])((object[])entry.Get())[1])[1];
if (name.StartsWith(search_string))
{
return(0);
}
return(name.CompareTo(search_string));
});
foreach (object v in query.Select(entry => ((object[])entry.Get())[1]))
{
Console.WriteLine(tp_person.Interpret(v));
}
}
