None of the metrics below are set by the cloning detection tool if thresholds are not met. That is, if an artefact has no CC measure in the output file, that does NOT mean that it has no line in common with other artefacts. In models, metrics default to 0 though.
The two main thresholds are:
A minimum size, to skip small artefacts
A minimum cloning ratio, to keep only similar artefacts
Length of the highest Longest Common Substring (LCS) among all cloned artefacts.
Clones are looked in the whole application, in artefacts with the same language and the same type.
Textual detection, using lines, with trailing spaces removed
Two artefacts are cloned if they have 90% of lines in common, for LC >= 10
Scope: all artefacts but the root node.
Length of the highest LCS among all cloned CFT.
Clones are looked in the whole application, in artefacts with the same language and the same type.
Algorithmic detection, using CFT characters
Two artefacts are cloned if they have 90% of characters in common, for CFT >= 50
Scope: all artefacts but the root node.
Number of clones in direct children of an artefact.
Parent clones are looked in the whole application, in artefacts with the same language and the same type.
Two classes may have two methods in common, for example, without being cloned. The CAC metric for these two classes will be two (assuming that they only have these two methods in common). Such artefacts should be re-factored (using inheritance for example).
Use both textual (CC > 0) and algorithmic (CFTC > 0) cloning when counting
Two parent artefacts are cloned if 25% of their direct children are cloned
Small children artefacts (LC < 10) are taken in account, using exact comparison
Scope: all artefacts but the root node.
Number of cloned artefacts.
Clones are looked in the whole application, in artefacts with the same language and the same type.
Use both textual (CC > 0) and algorithmic (CFTC > 0) cloning when counting
Scope: all artefacts but the root node.
Length of all Repeated Substrings in the artefact definition.
That is, duplicated blocks in a function for example.
Textual detection, using lines, with trailing spaces removed
The metric is triggered if blocks longer than 10 are found, for LC >= 10
Scope: files and all children artefacts.
Length of all Repeated Substrings in the artefact CFT.
That is, duplicated algorithmic blocks in a function for example.
Algorithmic detection, using CFT characters
The metric is triggered if blocks longer than 20 are found, for CFT >= 50
Scope: artefacts with a CFT, like functions.
Number of duplicated lines in an artefact.
Clones are looked in all descendants of the artefact. This basically sums all duplicated lines in descendants.
Use textual cloning (CC > 0) when counting
Scope: all artefacts.