// 独立 Task 版本
// 首次检索
public async Task <NormalResult> Search(
UseCollection useList,
IsbnSplitter isbnSplitter,
string strQueryWord,
int nMax,
string strFromStyle,
string strMatchStyle,
delegate_searchCompleted searchCompleted,
delegate_presentCompleted presentCompleted)
{
_searching = true;
try
{
List <Task> tasks = new List <Task>();
foreach (ZClientChannel channel in _channels)
{
if (_searching == false)
{
break;
}
if (channel.Enabled == false)
{
continue;
}
var task = Task.Factory.StartNew <NormalResult>(
() =>
{
return(SearchOne(channel,
useList,
isbnSplitter,
strQueryWord,
nMax,
strFromStyle,
strMatchStyle,
searchCompleted,
presentCompleted));
});
tasks.Add(task);
}
await Task.Run(() =>
{
Task.WaitAll(tasks.ToArray(), TimeSpan.FromMinutes(1));
}).ConfigureAwait(false);
return(new NormalResult());
}
finally
{
_searching = false;
}
}
// 针对一个特定 Z30.50 服务器发起检索
async Task <NormalResult> SearchOne(
ZClientChannel channel,
UseCollection useList,
IsbnSplitter isbnSplitter,
string strQueryWord,
int nMax,
string strFromStyle,
string strMatchStyle,
delegate_searchCompleted searchCompleted,
delegate_presentCompleted presentCompleted)
{
var ok = channel.Enter();
try
{
if (ok == false)
{
return(new NormalResult
{
Value = -1,
ErrorInfo = "通道已被占用",
ErrorCode = "channelInUse"
});
}
var _targetInfo = channel.TargetInfo;
IsbnConvertInfo isbnconvertinfo = new IsbnConvertInfo
{
IsbnSplitter = isbnSplitter,
ConvertStyle =
(_targetInfo.IsbnAddHyphen == true ? "addhyphen," : "")
+ (_targetInfo.IsbnRemoveHyphen == true ? "removehyphen," : "")
+ (_targetInfo.IsbnForce10 == true ? "force10," : "")
+ (_targetInfo.IsbnForce13 == true ? "force13," : "")
+ (_targetInfo.IsbnWild == true ? "wild," : "")
// TODO:
+ (_targetInfo.IssnForce8 == true ? "issnforce8," : "")
};
string strQueryString = "";
{
// 创建只包含一个检索词的简单 XML 检索式
// 注：这种 XML 检索式不是 Z39.50 函数库必需的。只是用它来方便构造 API 检索式的过程
string strQueryXml = BuildQueryXml(strQueryWord, strFromStyle);
// 将 XML 检索式变化为 API 检索式
var result = ZClient.ConvertQueryString(
useList,
strQueryXml,
isbnconvertinfo,
out strQueryString);
if (result.Value == -1)
{
searchCompleted?.Invoke(channel, new SearchResult(result));
var final_result = new NormalResult {
Value = result.Value, ErrorInfo = result.ErrorInfo
};
if (result.ErrorCode == "notFound")
{
final_result.ErrorCode = "useNotFound";
}
return(final_result);
}
}
REDO_SEARCH:
{
// return Value:
// -1 出错
// 0 成功
// 1 调用前已经是初始化过的状态，本次没有进行初始化
// InitialResult result = _zclient.TryInitialize(_targetInfo).GetAwaiter().GetResult();
// InitialResult result = _zclient.TryInitialize(_targetInfo).Result;
InitialResult result = await channel.ZClient.TryInitialize(_targetInfo);
if (result.Value == -1)
{
searchCompleted?.Invoke(channel, new SearchResult(result));
// TODO: 是否继续向后检索其他 Z39.50 服务器?
return(new NormalResult {
Value = -1, ErrorInfo = "Initialize error: " + result.ErrorInfo
});
}
}
// result.Value:
// -1 error
// 0 fail
// 1 succeed
// result.ResultCount:
// 命中结果集内记录条数 (当 result.Value 为 1 时)
SearchResult search_result = await channel.ZClient.Search(
strQueryString,
_targetInfo.DefaultQueryTermEncoding,
_targetInfo.DbNames,
_targetInfo.PreferredRecordSyntax,
"default");
if (search_result.Value == -1 || search_result.Value == 0)
{
if (search_result.ErrorCode == "ConnectionAborted")
{
// 自动重试检索
goto REDO_SEARCH;
}
}
searchCompleted?.Invoke(channel, search_result);
channel._resultCount = search_result.ResultCount;
if (search_result.Value == -1 ||
search_result.Value == 0 ||
search_result.ResultCount == 0)
{
return(new NormalResult()); // continue
}
var present_result = await _fetchRecords(channel, PresentBatchSize /*10*/);
presentCompleted?.Invoke(channel, present_result);
if (present_result.Value != -1)
{
channel._fetched += present_result.Records.Count;
}
return(new NormalResult());
}
finally
{
channel.Exit();
}
}
// 独立 Task 版本
// 首次检索
public async Task <NormalResult> SearchAsync(
UseCollection useList,
IsbnSplitter isbnSplitter,
string strQueryWord,
int nMax,
string strFromStyle,
string strMatchStyle,
delegate_searchCompleted searchCompleted,
delegate_presentCompleted presentCompleted)
{
_searching = true;
try
{
List <Task <NormalResult> > tasks = new List <Task <NormalResult> >();
List <ZClientChannel> channels = new List <ZClientChannel>();
foreach (ZClientChannel channel in _channels)
{
if (_searching == false)
{
break;
}
if (channel.Enabled == false)
{
continue;
}
var task = Task.Factory.StartNew(
async() =>
{
return(await SearchOne(channel,
useList,
isbnSplitter,
strQueryWord,
nMax,
strFromStyle,
strMatchStyle,
searchCompleted,
presentCompleted));
},
new CancellationToken(),
TaskCreationOptions.PreferFairness,
TaskScheduler.Default);
// tasks 和 channels 下标一一对应
tasks.Add(task.Unwrap());
channels.Add(channel);
Debug.Assert(tasks.Count == channels.Count);
}
/*
* await Task.Run(() =>
* {
* Task.WaitAll(tasks.ToArray(), TimeSpan.FromMinutes(1));
* }).ConfigureAwait(false);
*/
await Task.WhenAny(Task.WhenAll(tasks), Task.Delay(TimeSpan.FromMinutes(1)));
// 2020/11/4 观察返回值
List <string> errors = new List <string>();
foreach (var task in tasks)
{
if (task.IsCompleted == false)
{
// 中断那些超时后还没有结束的 channel
int index = tasks.IndexOf(task);
var channel = channels[index];
channel.ZClient.CloseConnection();
continue; // 不计入报错？
}
var result = await task;
if (result.Value == -1)
{
errors.Add(result.ErrorInfo);
}
}
if (errors.Count == 0)
{
return(new NormalResult());
}
else
{
return new NormalResult
{
Value = -1,
ErrorInfo = StringUtil.MakePathList(errors, "; ")
}
};
}
finally
{
_searching = false;
}
}
