26 lines
936 B
Text
26 lines
936 B
Text
# Example showing how to keep the last metric in order to compare it with the new one.
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#
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# Example Input:
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# cpu value=10i 1465839830100400201
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# cpu value=8i 1465839830100400301
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#
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# Example Output:
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# cpu_diff value=2i 1465839830100400301
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state = {
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"last": None
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}
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def apply(metric):
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# Load from the shared state the metric assigned to the key "last"
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last = state["last"]
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# Store the deepcopy of the new metric into the shared state and assign it to the key "last"
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# NB: To store a metric into the shared state you have to deep copy it
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state["last"] = deepcopy(metric)
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if last != None:
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# Create a new metric named "cpu_diff"
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result = Metric("cpu_diff")
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# Set the field "value" to the difference between the value of the last metric and the current one
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result.fields["value"] = last.fields["value"] - metric.fields["value"]
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result.time = metric.time
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return result
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