PIBIO_ENGINE_CHECK_FOR_DUPLICATE_FN回调函数 (winbio_adapter.h)

项目
03/13/2024

由 Windows 生物识别框架调用，以确定管道中的新模板是否复制数据库中已保存的任何模板，而不考虑与模板关联的标识。

语法

PIBIO_ENGINE_CHECK_FOR_DUPLICATE_FN PibioEngineCheckForDuplicateFn;

HRESULT PibioEngineCheckForDuplicateFn(
  [in, out] PWINBIO_PIPELINE Pipeline,
  [out]     PWINBIO_IDENTITY Identity,
  [out]     PWINBIO_BIOMETRIC_SUBTYPE SubFactor,
  [out]     PBOOLEAN Duplicate
)
{...}

参数

[in, out] Pipeline

指向与执行操作的生物识别单元关联的 WINBIO_PIPELINE 结构的指针。

[out] Identity

指向 WINBIO_IDENTITY 结构的指针，该结构接收存储在数据库中的重复模板的 GUID 或 SID。

[out] SubFactor

指向 WINBIO_BIOMETRIC_SUBTYPE 变量的指针，该变量接收与数据库中重复模板关联的子因子。

[out] Duplicate

指向布尔值的指针，该值指定是否在数据库中找到匹配的模板。

返回值

返回代码	说明
E_POINTER	强制指针参数为 NULL。
WINBIO_E_INVALID_DEVICE_STATE	管道引擎上下文中没有注册模板。

注解

Windows 生物识别框架在将新的注册模板提交到生物识别单元的数据库之前调用此函数。此函数的目的是防止在引擎适配器匹配空间中发生冲突。冲突可能会导致误报匹配。

此函数应使用存储适配器执行基于内容的查询，以确定模板是否与数据库中已有的任何模板匹配。

如果此方法在数据库中找到重复的模板，则应返回匹配模板 的 Identity 和 SubFactor 值，将 Duplicate 参数设置为 TRUE，并返回 S_OK 的 HRESULT 值。

如果此方法在数据库中找不到匹配的模板，则应将 Duplicate 参数设置为 FALSE ，但返回 hrESULT 值S_OK。

示例

以下伪代码演示了此函数的一种可能实现。该示例不编译。必须根据自己的目的调整它。

//////////////////////////////////////////////////////////////////////////////////////////
//
// EngineAdapterCheckForDuplicate
// 
// Purpose:
//      Determines whether a new template in the pipeline duplicates any 
//      template already saved in the database regardless of the identity 
//      associated with the templates.
//
// Parameters:
//      Pipeline    - Pointer to a WINBIO_PIPELINE structure associated 
//                    with the biometric unit performing the operation
//      Identity    - GUID or SID of the duplicate template stored in the 
//                    database
//      SubFactor   - sub-factor associated with the duplicate template in
//                    the database
//      Duplicate   - Boolean value that specifies whether a matching template 
//                    was found in the database
//
static HRESULT
WINAPI
EngineAdapterCheckForDuplicate(
    __inout PWINBIO_PIPELINE Pipeline,
    __out PWINBIO_IDENTITY Identity,
    __out PWINBIO_BIOMETRIC_SUBTYPE SubFactor,
    __out PBOOLEAN Duplicate
    )
{
    HRESULT hr = S_OK;
    WINBIO_REJECT_DETAIL rejectDetail = 0;
    SIZE_T recordCount = 0;
    SIZE_T index = 0;
    WINBIO_STORAGE_RECORD thisRecord;
    BOOLEAN match = FALSE;
    DWORD indexVector[NUMBER_OF_TEMPLATE_BINS] = {0};

    // Verify that pointer arguments are not NULL.
    if (!ARGUMENT_PRESENT(Pipeline)  ||
        !ARGUMENT_PRESENT(Identity)  ||
        !ARGUMENT_PRESENT(SubFactor) ||
        !ARGUMENT_PRESENT(Duplicate))
    {
        hr = E_POINTER;
        goto cleanup;
    }

    // Retrieve the context from the pipeline.
    PWINBIO_ENGINE_CONTEXT context = 
           (PWINBIO_ENGINE_CONTEXT)Pipeline->EngineContext;

    // Return if an enrollment is not in progress. This example assumes that 
    // an enrollment object is part of your engine context structure.
    if (context->Enrollment.InProgress != TRUE)
    {
        hr = WINBIO_E_INVALID_DEVICE_STATE;
        goto cleanup;
    }

    // Zero the memory pointed to by the Identity argument and set the
    // pointer to NULL.
    ZeroMemory( Identity, sizeof(WINBIO_IDENTITY));
    Identity->Type = WINBIO_ID_TYPE_NULL;

    // Eliminate sub-factor information.
    *SubFactor  = WINBIO_SUBTYPE_NO_INFORMATION;

    // Initialize the Boolean Duplicate argument to FALSE.
    *Duplicate  = FALSE;

    // If your adapter supports index vectors to place templates into buckets,
    // call a custom function (_AdapterCreateIndexVector) to create an index 
    // vector from the template data in the feature set. In this example, the
    // engine adapter context attached to the pipeline contains an Enrollment
    // member that references the current template. Your implementation may
    // differ.
    hr = _AdapterCreateIndexVector(
                context, 
                context->Enrollment.Template, 
                context->Enrollment.TemplateSize,
                indexVector, 
                NUMBER_OF_TEMPLATE_BINS, 
                &rejectDetail
                );
    if (FAILED(hr))
    {
        goto cleanup;
    }

    // Retrieve the records in the index vector. If your adapter does not support 
    // index vectors (the vector length is zero), calling the WbioStorageQueryByContent 
    // function will retrieve all records.
    // WbioStorageQueryByContent is a wrapper function in the Winbio_adapter.h 
    // header file.
    hr = WbioStorageQueryByContent(
            Pipeline,
            WINBIO_SUBTYPE_ANY,
            indexVector,
            NUMBER_OF_TEMPLATE_BINS
            );
    if (FAILED(hr))
    {
        goto cleanup;
    }

    // Determine the size of the result set. WbioStorageGetRecordCount is a wrapper
    // function in the Winbio_adapter.h header file.
    hr = WbioStorageGetRecordCount( Pipeline, &recordCount);
    if (FAILED(hr))
    {
        goto cleanup;
    }

    // Point the result set cursor at the first record. WbioStorageFirstRecord
    // is a wrapper function in the Winbio_adapter.h header file.
    hr = WbioStorageFirstRecord( Pipeline );
    if (FAILED(hr))
    {
        goto cleanup;
    }

    // Iterate through all records in the result set and determine which record
    // matches the current feature set. WbioStorageGetCurrentRecord is a wrapper
    // function in the Winbio_adapter.h header file. 
    for (index = 0; index < recordCount; ++index)
    {
        hr = WbioStorageGetCurrentRecord( Pipeline, &thisRecord );
        if (FAILED(hr))
        {
            goto cleanup;
        }

        // Call a custom function (_AdapterCompareTemplateToCurrentFeatureSet) to
        // compare the feature set attached to the pipeline with the template
        // retrieved from storage.
        // If the template and feature set match, return S_OK and set the match
        // argument to TRUE. If the template and feature set do not match, return
        // S_OK and set the match argument to FALSE. If the function fails for some
        // other reason, return a failure HRESULT.
        hr = _AdapterCompareTemplateToEnrollmentTemplate( 
                    context, 
                    context->Enrollment.Template, 
                    context->Enrollment.TemplateSize,
                    thisRecord.TemplateBlob, 
                    thisRecord.TemplateBlobSize,
                    &match
                    );
        if (FAILED(hr))
        {
            goto cleanup;
        }
        if (match)
        {
            break;
        }

        // Retrieve the next record.
        hr = WbioStorageNextRecord( Pipeline );
        if (FAILED(hr))
        {
            if (hr == WINBIO_E_DATABASE_NO_MORE_RECORDS)
            {
                hr = S_OK;
                break;
            }
            else
            {
                goto cleanup;
            }
        }
    }

    // If there is a duplicate template in the database, return information about
    // it to the caller.
    if (match)
    {
        CopyMemory( Identity, thisRecord.Identity, sizeof(WINBIO_IDENTITY));
        *SubFactor = thisRecord.SubFactor;
        *Duplicate = TRUE;
        hr = S_OK;
    }

cleanup:

    // There are no duplicates. This is an acceptable result.
    if (hr == WINBIO_E_DATABASE_NO_RESULTS)
    {
        hr = S_OK;
    }
    return hr;
}

要求

要求	值
最低受支持的客户端	Windows 7 [仅限桌面应用]
最低受支持的服务器	Windows Server 2008 R2 [仅限桌面应用]
目标平台	Windows
标头	winbio_adapter.h (包括 Winbio_adapter.h)

另请参阅

插件函数

PIBIO_ENGINE_CHECK_FOR_DUPLICATE_FN回调函数 (winbio_adapter.h)

语法

参数

返回值

注解

示例

要求

另请参阅

反馈

反馈

其他资源