// 解码Present请求包
public static int Decode_PresentRequest(
BerNode root,
out PresentRequestInfo info,
out string strError)
{
strError = "";
int nRet = 0;
info = new PresentRequestInfo();
Debug.Assert(root != null, "");
if (root.m_uTag != BerTree.z3950_presentRequest)
{
strError = "root tag is not z3950_presentRequest";
return -1;
}
for (int i = 0; i < root.ChildrenCollection.Count; i++)
{
BerNode node = root.ChildrenCollection[i];
switch (node.m_uTag)
{
case BerTree.z3950_ReferenceId: // 2
info.m_strReferenceId = node.GetCharNodeData();
break;
case BerTree.z3950_ResultSetId: // 31 resultSetId (IntenationalString)
info.m_strResultSetID = node.GetCharNodeData();
break;
case BerTree.z3950_resultSetStartPoint: // 30 resultSetStartPoint (Integer)
info.m_lResultSetStartPoint = node.GetIntegerNodeData();
break;
case BerTree.z3950_numberOfRecordsRequested: // 29 numberOfRecordsRequested (Integer)
info.m_lNumberOfRecordsRequested = node.GetIntegerNodeData();
break;
case BerTree.z3950_ElementSetNames: // 19 ElementSetNames (complicates)
{
List<string> elementset_names = null;
nRet = DecodeElementSetNames(node,
out elementset_names,
out strError);
if (nRet == -1)
return -1;
info.m_elementSetNames = elementset_names;
}
break;
default:
break;
}
}
return 0;
}
// 编码(构造) Present响应包
int Encode_PresentResponse(PresentRequestInfo info,
out byte[] baPackage)
{
baPackage = null;
int nRet = 0;
string strError = "";
DiagFormat diag = null;
BerTree tree = new BerTree();
BerNode root = null;
string strResultSetName = info.m_strResultSetID;
if (String.IsNullOrEmpty(strResultSetName) == true)
strResultSetName = "default";
long lStart = info.m_lResultSetStartPoint - 1;
long lNumber = info.m_lNumberOfRecordsRequested;
long lPerCount = lNumber;
long lHitCount = 0;
List<string> paths = new List<string>();
int nPresentStatus = 5; // failed
// 获取结果集中需要部分的记录path
long lOffset = lStart;
int nCount = 0;
for (; ; )
{
DigitalPlatform.LibraryClient.localhost.Record[] searchresults = null;
long lRet = this._channel.GetSearchResult(
null, // stop,
strResultSetName, // strResultSetName
lOffset,
lPerCount,
"id",
"zh", // this.Lang,
out searchresults,
out strError);
/*
// 测试获取结果集失败的情况，返回非代理诊断记录
lRet = -1;
strError = "测试检索错误信息！";
* */
if (lRet == -1)
{
SetPresentDiagRecord(ref diag,
2, // temporary system error
strError);
break;
}
if (lRet == 0)
{
// goto ERROR1 ?
}
lHitCount = lRet; // 顺便得到命中记录总条数
// 转储
for (int i = 0; i < searchresults.Length; i++)
{
paths.Add(searchresults[i].Path);
}
lOffset += searchresults.Length;
lPerCount -= searchresults.Length;
nCount += searchresults.Length;
if (lOffset >= lHitCount
|| lPerCount <= 0
|| nCount >= lNumber)
{
//
break;
}
}
// TODO: 需要注意多个错误是否形成多个diag记录？V2不允许这样，V3允许这样
if (lHitCount < info.m_lResultSetStartPoint
&& diag == null)
{
strError = "start参数值 "
+ info.m_lResultSetStartPoint
+ " 超过结果集中记录总数 "
+ lHitCount;
// return -1; // 如果表示错误状态？
SetPresentDiagRecord(ref diag,
13, // Present request out-of-range
strError);
}
int MAX_PRESENT_RECORD = 100;
// 限制每次 present 的记录数量
if (lNumber > MAX_PRESENT_RECORD)
lNumber = MAX_PRESENT_RECORD;
long nNextResultSetPosition = 0;
//
if (lHitCount < (lStart - 1) + lNumber)
{
// 是 present 错误，但还可以调整 lNumber
lNumber = lHitCount - (lStart - 1);
nNextResultSetPosition = 0;
}
else
{
//
nNextResultSetPosition = lStart + lNumber + 1;
}
root = tree.m_RootNode.NewChildConstructedNode(
BerTree.z3950_presentResponse,
BerNode.ASN1_CONTEXT);
// reference id
if (String.IsNullOrEmpty(info.m_strReferenceId) == false)
{
root.NewChildCharNode(BerTree.z3950_ReferenceId,
BerNode.ASN1_CONTEXT,
Encoding.UTF8.GetBytes(info.m_strReferenceId));
}
List<RetrivalRecord> records = new List<RetrivalRecord>();
// 获取要返回的MARC记录
if (diag == null)
{
// 记录编码格式为 GRS-1 (generic-record-syntax-1) :
// EXTERNAL
// --- OID (Object Identifier)
// --- MARC (OCTET STRING)
// m_strOID = _T("1.2.840.10003.5.1"); // OID of UNIMARC
// m_strOID = _T("1.2.840.10003.5.10"); // OID of USMARC //
// 需要建立一个数据库名和oid的对照表，方面快速取得数据库MARC syntax OID
// TODO: 编码过程中，可能会发现记录太多，总尺寸超过Initial中规定的prefered message size。
// 这样需要减少返回的记录数量。这样，就需要先做这里的循环，后构造另外几个参数
int nSize = 0;
for (int i = 0; i < (int)lNumber; i++)
{
// 编码 N 条 MARC 记录
//
// if (m_bStop) return false;
// 取出数据库指针
// lStart 不是 0 起点的
string strPath = paths[i];
// 解析出数据库名和ID
string strDbName = Global.GetDbName(strPath);
string strRecID = Global.GetRecordID(strPath);
// 如果取得的是xml记录，则根元素可以看出记录的marc syntax，进一步可以获得oid；
// 如果取得的是MARC格式记录，则需要根据数据库预定义的marc syntax来看出oid了
string strMarcSyntaxOID = GetMarcSyntaxOID(strDbName);
byte[] baMARC = null;
RetrivalRecord record = new RetrivalRecord();
record.m_strDatabaseName = strDbName;
// 根据书目库名获得书目库属性对象
BiblioDbProperty prop = this._service.GetDbProperty(
strDbName,
false);
nRet = GetMARC(strPath,
info.m_elementSetNames,
prop != null ? prop.AddField901 : false,
out baMARC,
out strError);
/*
// 测试记录群中包含诊断记录
if (i == 1)
{
nRet = -1;
strError = "测试获取记录错误";
}*/
if (nRet == -1)
{
record.m_surrogateDiagnostic = new DiagFormat();
record.m_surrogateDiagnostic.m_strDiagSetID = "1.2.840.10003.4.1";
record.m_surrogateDiagnostic.m_nDiagCondition = 14; // system error in presenting records
record.m_surrogateDiagnostic.m_strAddInfo = strError;
}
else if (nRet == 0)
{
record.m_surrogateDiagnostic = new DiagFormat();
record.m_surrogateDiagnostic.m_strDiagSetID = "1.2.840.10003.4.1";
record.m_surrogateDiagnostic.m_nDiagCondition = 1028; // record deleted
record.m_surrogateDiagnostic.m_strAddInfo = strError;
}
else if (String.IsNullOrEmpty(strMarcSyntaxOID) == true)
{
// 根据数据库名无法获得marc syntax oid。可能是虚拟库检索命中记录所在的物理库没有在dp2zserver.xml中配置。
record.m_surrogateDiagnostic = new DiagFormat();
record.m_surrogateDiagnostic.m_strDiagSetID = "1.2.840.10003.4.1";
record.m_surrogateDiagnostic.m_nDiagCondition = 109; // database unavailable // 似乎235:database dos not exist也可以
record.m_surrogateDiagnostic.m_strAddInfo = "根据数据库名 '" + strDbName + "' 无法获得marc syntax oid";
}
else
{
record.m_external = new External();
record.m_external.m_strDirectRefenerce = strMarcSyntaxOID;
record.m_external.m_octectAligned = baMARC;
}
nSize += record.GetPackageSize();
if (i == 0)
{
// 连一条记录也放不下
if (nSize > this._lExceptionalRecordSize)
{
Debug.Assert(diag == null, "");
SetPresentDiagRecord(ref diag,
17, // record exceeds Exceptional_record_size
"记录尺寸 " + nSize.ToString() + " 超过 Exceptional_record_size " + this._lExceptionalRecordSize.ToString());
lNumber = 0;
break;
}
}
else
{
if (nSize >= this._lPreferredMessageSize)
{
// 调整返回的记录数
lNumber = i;
break;
}
}
records.Add(record);
}
}
// numberOfRecordsReturned
root.NewChildIntegerNode(BerTree.z3950_NumberOfRecordsReturned, // 24
BerNode.ASN1_CONTEXT, // ASN1_PRIMITIVE BUG!!!
BitConverter.GetBytes((long)lNumber));
if (diag != null)
nPresentStatus = 5;
else
nPresentStatus = 0;
// nextResultSetPosition
// if 0, that's end of the result set
// else M+1, M is 最后一次 present response 的最后一条记录在 result set 中的 position
root.NewChildIntegerNode(BerTree.z3950_NextResultSetPosition, // 25
BerNode.ASN1_CONTEXT, // ASN1_PRIMITIVE BUG!!!
BitConverter.GetBytes((long)nNextResultSetPosition));
// presentStatus
// success (0),
// partial-1 (1),
// partial-2 (2),
// partial-3 (3),
// partial-4 (4),
// failure (5).
root.NewChildIntegerNode(BerTree.z3950_presentStatus, // 27
BerNode.ASN1_CONTEXT, // ASN1_PRIMITIVE BUG!!!
BitConverter.GetBytes((long)nPresentStatus));
// 诊断记录
if (diag != null)
{
BerNode nodeDiagRoot = root.NewChildConstructedNode(BerTree.z3950_nonSurrogateDiagnostic, // 130
BerNode.ASN1_CONTEXT);
diag.BuildBer(nodeDiagRoot);
/*
nodeDiagRoot.NewChildOIDsNode(6,
BerNode.ASN1_UNIVERSAL,
diag.m_strDiagSetID); // "1.2.840.10003.4.1"
nodeDiagRoot.NewChildIntegerNode(2,
BerNode.ASN1_UNIVERSAL,
BitConverter.GetBytes((long)diag.m_nDiagCondition));
if (String.IsNullOrEmpty(diag.m_strAddInfo) == false)
{
nodeDiagRoot.NewChildCharNode(26,
BerNode.ASN1_UNIVERSAL,
Encoding.UTF8.GetBytes(diag.m_strAddInfo));
}
* */
}
// 如果 present 是非法的，到这里打包完成，可以返回了
if (0 != nPresentStatus)
goto END1;
// 编码记录BER树
// 以下为 present 成功时，打包返回记录。
// present success
// presRoot records child, constructed (choice of ... ... optional)
// if present fail, then may be no records 'node'
// Records ::= CHOICE {
// responseRecords [28] IMPLICIT SEQUENCE OF NamePlusRecord,
// nonSurrogateDiagnostic [130] IMPLICIT DefaultDiagFormat,
// multipleNonSurDiagnostics [205] IMPLICIT SEQUENCE OF DiagRec}
// 当 present 成功时，response 选择了 NamePlusRecord (数据库名 + 记录)
BerNode node = root.NewChildConstructedNode(BerTree.z3950_dataBaseOrSurDiagnostics, // 28
BerNode.ASN1_CONTEXT);
for (int i = 0; i < records.Count; i++)
{
RetrivalRecord record = records[i];
record.BuildNamePlusRecord(node);
}
END1:
baPackage = null;
root.EncodeBERPackage(ref baPackage);
return 0;
}
