comparison mercurial/debugcommands.py @ 38646:93313f66b69b

debugdeltachain: avoid division by zero when a chain is empty

The two ratios chainratio and extraratio are computed using dividers
that may be zero when the file is empty.
As the denominators are integers, the limit of the ratio "just before zero" is
the numerator value itself.
If the numerator itself is zero, the ratio value is still meaningful: in both
cases, a "good" value is a low ratio, and a size of zero is the optimal case.

38645:02850baddadd

        try:
            prevrev = chain[-2]
        except IndexError:
            prevrev = -1

        chainratio = float(chainsize) / float(uncomp)
        extraratio = float(extradist) / float(chainsize)

        fm.startitem()
        fm.write('rev chainid chainlen prevrev deltatype compsize '
                 'uncompsize chainsize chainratio lindist extradist '
                 'extraratio',

38646:93313f66b69b

        try:
            prevrev = chain[-2]
        except IndexError:
            prevrev = -1

        if uncomp != 0:
            chainratio = float(chainsize) / float(uncomp)
        else:
            chainratio = chainsize

        if chainsize != 0:
            extraratio = float(extradist) / float(chainsize)
        else:
            extraratio = extradist

        fm.startitem()
        fm.write('rev chainid chainlen prevrev deltatype compsize '
                 'uncompsize chainsize chainratio lindist extradist '
                 'extraratio',