PIBIO_ENGINE_IDENTIFY_FEATURE_SET_FN回调函数 （winbio_adapter.h）

由 Windows 生物识别框架调用，以从当前功能集生成模板，并在数据库中找到匹配的模板。 如果可以找到匹配项，则引擎适配器必须使用存储模板中的相应信息填充 Identity、 SubFactor、 PayloadBlob 参数。

Syntax

PIBIO_ENGINE_IDENTIFY_FEATURE_SET_FN PibioEngineIdentifyFeatureSetFn;

HRESULT PibioEngineIdentifyFeatureSetFn(
  [in, out] PWINBIO_PIPELINE Pipeline,
  [out]     PWINBIO_IDENTITY Identity,
  [out]     PWINBIO_BIOMETRIC_SUBTYPE SubFactor,
  [out]     PUCHAR *PayloadBlob,
  [out]     PSIZE_T PayloadBlobSize,
  [out]     PUCHAR *HashValue,
  [out]     PSIZE_T HashSize,
  [out]     PWINBIO_REJECT_DETAIL RejectDetail
)
{...}

参数

[in, out] Pipeline

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

[out] Identity

指向包含从数据库恢复的模板的 GUID 或 SID 的 WINBIO_IDENTITY 结构的指针。 仅当找到匹配项时，才会返回此值。

[out] SubFactor

一 个WINBIO_BIOMETRIC_SUBTYPE 值，该值接收与数据库中模板关联的子因素。 有关更多详细信息，请参阅“备注”部分。 仅当找到匹配项时，才会返回此值。

[out] PayloadBlob

接收指向使用模板保存的有效负载数据的指针的变量的地址。 如果没有有效负载数据，请将此值设置为 NULL。

[out] PayloadBlobSize

指向一个变量的指针，该变量接收 PayloadBlob 参数指定的缓冲区的大小（以字节为单位）。 如果没有有效负载数据，请将此值设置为零。

[out] HashValue

接收指向模板生成的哈希值的指针的变量的地址。 如果引擎适配器不支持哈希生成，请将此值设置为 NULL。

[out] HashSize

指向一个变量的指针，该变量接收 HashValue 参数指定的缓冲区的大小（以字节为单位）。 如果引擎适配器不支持哈希生成，请将此值设置为零。

[out] RejectDetail

如果捕获失败阻止引擎执行匹配作，则指向接收其他信息的变量的指针。 如果最近的捕获成功，请将此参数设置为零。 为指纹捕获定义了以下值：

• WINBIO_FP_TOO_HIGH
• WINBIO_FP_TOO_LOW
• WINBIO_FP_TOO_LEFT
• WINBIO_FP_TOO_RIGHT
• WINBIO_FP_TOO_FAST
• WINBIO_FP_TOO_SLOW
• WINBIO_FP_POOR_QUALITY
• WINBIO_FP_TOO_SKEWED
• WINBIO_FP_TOO_SHORT
• WINBIO_FP_MERGE_FAILURE

返回值

如果函数成功，它将返回S_OK，以指示上次更新成功，无需其他功能集来完成模板。 如果函数失败，则它必须返回以下 HRESULT 值之一来指示错误。

注解

用于生成模板哈希的算法是由最近在此管道上调用到 EngineAdapterSetHashAlgorithm 选择的。

此函数返回的哈希值（如果有）是在数据库中找到的注册模板的哈希，而不是附加到管道的匹配模板。

EngineAdapterIdentifyFeatureSet 函数成功返回后，PayloadBlob 和 HashValue 缓冲区由引擎适配器拥有和管理。 引擎适配器必须使缓冲区地址对此管道有效，直到下一次调用 EngineAdapterClearContext。

例子

以下伪代码显示了此函数的一个可能实现。 该示例未编译。 你必须适应你的目的。

//////////////////////////////////////////////////////////////////////////////////////////
//
// EngineAdapterIdentifyFeatureSet
//
// Purpose:
//      Build a template from the current feature set and locate a matching 
//      template in the database.
//
// Parameters:
//      Pipeline        - Pointer to a WINBIO_PIPELINE structure associated 
//                        with the biometric unit performing the operation
//      Identity        - The GUID or SID of the template recovered from the 
//                        database
//      SubFactor       - Sub-factor associated with the template in the 
//                        database
//      PayloadBlob     - Payload data saved with the template
//      PayloadBlobSize - Size, in bytes, of the buffer specified by the 
//                        PayloadBlob parameter. 
//      HashValue       - Hash value for the template
//      HashSize        - Size, in bytes, of the buffer specified by the 
//                        HashValue parameter.
//      RejectDetail    - Receives additional information if a capture 
//                        failure prevents the engine from performing a matching 
//                        operation.
//      
static HRESULT
WINAPI
EngineAdapterIdentifyFeatureSet(
    __inout PWINBIO_PIPELINE Pipeline,
    __out PWINBIO_IDENTITY Identity,
    __out PWINBIO_BIOMETRIC_SUBTYPE SubFactor,
    __out PUCHAR *PayloadBlob,
    __out PSIZE_T PayloadBlobSize,
    __out PUCHAR *HashValue,
    __out PSIZE_T HashSize,
    __out PWINBIO_REJECT_DETAIL RejectDetail
    )
{
    HRESULT hr = S_OK;
    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(PayloadBlob) ||
        !ARGUMENT_PRESENT(PayloadBlobSize) ||
        !ARGUMENT_PRESENT(HashValue) ||
        !ARGUMENT_PRESENT(HashSize) ||
        !ARGUMENT_PRESENT(RejectDetail))
    {
        hr = E_POINTER;
        goto cleanup;
    }

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

    // Initialize the return values.
    ZeroMemory( Identity, sizeof(WINBIO_IDENTITY));
    Identity->Type = WINBIO_ID_TYPE_NULL;
    *SubFactor          = WINBIO_SUBTYPE_NO_INFORMATION;
    *PayloadBlob        = NULL;
    *PayloadBlobSize    = 0;
    *HashValue          = NULL;
    *HashSize           = 0;
    *RejectDetail       = 0;

    // The biometric unit cannot perform verification or identification
    // operations while it is performing an enrollment sequence.
    if (context->Enrollment.InProgress == TRUE)
    {
        hr = WINBIO_E_ENROLLMENT_IN_PROGRESS;
        goto cleanup;
    }

    // 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 a FeatureSet
    // member.
    hr = _AdapterCreateIndexVector(
                context, 
                context->FeatureSet,
                context->FeatureSetSize,
                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 do not match, return WINBIO_E_NO_MATCH
        // and set the Match parameter to FALSE.
        // If your custom function cannot process the feature set, return 
        // WINBIO_E_BAD_CAPTURE and set extended error information in the 
        // RejectDetail parameter.
        hr = _AdapterCompareTemplateToCurrentFeatureSet( 
                    context, 
                    context->FeatureSet,
                    context->FeatureSetSize,
                    thisRecord.TemplateBlob, 
                    thisRecord.TemplateBlobSize,
                    &match,
                    RejectDetail 
                    );
        if (FAILED(hr) && hr != WINBIO_E_NO_MATCH)
        {
            goto cleanup;
        }
        if (match)
        {
            break;
        }

        hr = WbioStorageNextRecord( Pipeline );
        if (FAILED(hr))
        {
            if (hr == WINBIO_E_DATABASE_NO_MORE_RECORDS)
            {
                hr = S_OK;
                break;
            }
            else
            {
                goto cleanup;
            }
        }
    }

    if (match)
    {
        // If there is a match and if your engine adapter supports template
        // hashing, call a custom function (_AdapterGenerateHashForTemplate)
        // to calculate the hash. Save the hash value in the context area of
        // the engine adapter.
        // Skip this step if your adapter does not support template hashing.
        hr = _AdapterGenerateHashForTemplate(
                    context,
                    thisRecord.TemplateBlob, 
                    thisRecord.TemplateBlobSize,
                    context->HashBuffer,
                    &context->HashSize
                    );
        if (FAILED(hr))
        {
            goto cleanup;
        }

        // Return information about the matching template to the caller.
        CopyMemory( Identity, thisRecord.Identity, sizeof(WINBIO_IDENTITY));

        *SubFactor          = thisRecord.SubFactor;
        *PayloadBlob        = thisRecord.PayloadBlob;
        *PayloadBlobSize    = thisRecord.PayloadBlobSize;
        *HashValue          = &context->HashBuffer;
        *HashSize           = context->HashSize;
    }
    else
    {
        hr = WINBIO_E_UNKNOWN_ID;
    }

cleanup:

    if (hr == WINBIO_E_DATABASE_NO_RESULTS)
    {
        hr = WINBIO_E_UNKNOWN_ID;
    }
    return hr;
}

要求

另请参阅

EngineAdapterVerifyFeatureSet

插件函数