/// <summary>
/// 定义一个全局访问点，设置为静态方法
/// 则在类的外部便无需实例化就可以调用该方法
/// </summary>
/// <returns>返回单例fieldsInstance</returns>
public static Fields GetInstance()
{
//第一重 singleton == null
if(fieldsInstance==null)
{
lock (syncObj)
{
//第二重 singleton == null
if (fieldsInstance == null)
{
fieldsInstance = new Fields();
}
}
}
return fieldsInstance;
}
/// <summary>
/// checks that top-level statistics on Fields are the same
/// </summary>
public void AssertFieldStatisticsEquals(string info, Fields leftFields, Fields rightFields)
{
if (leftFields.Size != -1 && rightFields.Size != -1)
{
Assert.AreEqual(leftFields.Size, rightFields.Size, info);
}
}
/// <summary>
/// Fields api equivalency
/// </summary>
public void AssertFieldsEquals(string info, IndexReader leftReader, Fields leftFields, Fields rightFields, bool deep)
{
// Fields could be null if there are no postings,
// but then it must be null for both
if (leftFields == null || rightFields == null)
{
Assert.IsNull(leftFields, info);
Assert.IsNull(rightFields, info);
return;
}
AssertFieldStatisticsEquals(info, leftFields, rightFields);
IEnumerator<string> leftEnum = leftFields.GetEnumerator();
IEnumerator<string> rightEnum = rightFields.GetEnumerator();
while (leftEnum.MoveNext())
{
string field = leftEnum.Current;
rightEnum.MoveNext();
Assert.AreEqual(field, rightEnum.Current, info);
AssertTermsEquals(info, leftReader, leftFields.Terms(field), rightFields.Terms(field), deep);
}
Assert.IsFalse(rightEnum.MoveNext());
}
