spark技术分享AvroDataToCatalyst Unary Expression
AvroDataToCatalyst is a unary expression that represents from_avro function in a structured query.
AvroDataToCatalyst takes the following when created:
AvroDataToCatalyst generates Java source code (as ExprCode) for code-generated expression evaluation.
Generating Java Source Code (ExprCode) For Code-Generated Expression Evaluation — doGenCode Method
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doGenCode(ctx: CodegenContext, ev: ExprCode): ExprCode |
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Note
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doGenCode is part of Expression Contract to generate a Java source code (ExprCode) for code-generated expression evaluation.
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doGenCode requests the CodegenContext to generate code to reference this AvroDataToCatalyst instance.
In the end, doGenCode defineCodeGen with the function f that uses nullSafeEval.
nullSafeEval Method
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nullSafeEval(input: Any): Any |
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Note
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nullSafeEval is part of the UnaryExpression Contract to…FIXME.
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nullSafeEval…FIXME
