Don't call Pipeline::valid() recursively when a row is discarded
#119
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Currently, when a row is discarded (e.g. by the Transformer), the Pipeline::valid function manually increments the current key, then calls itself recursively. When discarding many rows, this not only leads to extremely deep call stacks, it also seems to cause execution time to grow linearly as extraction loop progresses. By changing the discarded behaviour to a simple `break;` statement the valid function will simply return `true`, bypassing subsequent steps (e.g. the Loader) and progressing on to the next row without recursion.
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NB. I cannot see any reason why the recursion behaviour was included in the first place; if I have misunderstood, please let me know. |
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Thank you @ollyollyollyltd for this input! |
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Currently, when a row is discarded (e.g. by the Transformer), the Pipeline::valid function manually increments the current key, then calls itself recursively. When discarding many rows, this not only leads to extremely deep call stacks, it also seems to cause execution time to grow linearly as extraction loop progresses.
By changing the discarded behaviour to a simple
break;statement the valid function will simply returntrue, bypassing subsequent steps (e.g. the Loader) and progressing on to the next row without recursion.