/// <summary>
/// 创建空倒排列表
/// </summary>
/// <param name="word">单词</param>
/// <returns></returns>
private IndexList CreateEmptyIndexList(WordAtom word)
{
var posList = new IndexList();
posList.Id =ObjectId.GenerateNewId().ToString();
posList.IndexAtoms = new ConcurrentDictionary<string, IndexAtom>();
return posList;
}
/// <summary>
/// 根据单词获取一个倒排列表
/// </summary>
/// <param name="word"></param>
/// <returns></returns>
public async Task<IndexList> GetOrAddIndexList(WordAtom word)
{
HashIndexList hashIndex = null;
if (CurrentIndexList.TryGetValue(word.Word, out hashIndex))
{
return hashIndex.List;
}
int hashcode = word.GetHashCode();
DictAndState dict;
MongoClient Client = Mongo.GetNode(hashcode.ToString());
if (!DictList.TryGetValue(hashcode, out dict))
{
dict = new DictAndState()
{
IsNew = true,
Dict = new HashDict()
{
Hashcode = hashcode,
Words = new ConcurrentDictionary<string, string>()
}
};
hashIndex = new HashIndexList() { Hashcode = hashcode, List = CreateEmptyIndexList(word), IsNew = true };
dict.Dict.Words.TryAdd(word.Word, hashIndex.List.Id);
if (!DictList.TryAdd(hashcode, dict))
{
return null;
}
}
string listId;
if (dict.Dict.Words.TryGetValue(word.Word, out listId))
{
if (hashIndex == null || listId != hashIndex.List.Id)
{
var indexListDb = Client.GetDatabase(Config.IndexListDbName).GetCollection<BsonDocument>(ListHash.GetNode(hashcode.ToString()));
var index = await indexListDb.Find(Builders<BsonDocument>.Filter.Eq("_id", listId)).SingleOrDefaultAsync();
hashIndex = new HashIndexList()
{
Hashcode = hashcode,
IsNew = false,
List = new IndexList()
{
Id = listId,
IndexAtoms = index != null ? new ConcurrentDictionary<string, IndexAtom>(AtomDerializer.UnpackSingleObject(index["IndexAtoms"].AsByteArray)) : new ConcurrentDictionary<string, IndexAtom>()
}
};
}
}
if (!CurrentIndexList.TryAdd(word.Word, hashIndex))
return null;
return hashIndex.List;
}