Statistics for E-Commerce system

[Stephen Colebourne]

1.3 million LOC
Old sourcebase, lots of refactoring down the years
Java EE, Servlets but not EJB
Two parts - low level utilities, and main E-commerce codebase

Low level utilities
-------------------------
all catchs             : 549
all conditionals       : 297
all ifs                : 1521
all integer literals   : 4863
big integer literals(undescores): 326
byte literal           : 0
catch in finally       : 14
elvis                  : 86  --> correct value 36
instanceof switch      : 27
loop with remove       : 5  --> correct value 33
multi catch            : 31
object switch          : 81
rethrow clause         : 271
string in switch       : 23
Files:564

 while \(.+?\.hasNext\(\)\)
all hasNext() while    : 39
 for \(Iterator
all iterator() for     : 68
 for \(int
all int for            : 375
 for \(
all for                : 631

Elvis-conditional = 36/297 = 12.1%
Loop-remove       = 33/631 =  5.2%
Multi-catch         = 31/549 = 5.6%


Main E-Commerce system
---------------------------------------
(counted in three parts to avoid out of memory in the tool, and to
demonstrate how different types of code affect the results)
Main code (most of the business logic:
all catchs             : 2592
all conditionals       : 2185
all ifs                : 7431
all integer literals   : 45473
big integer literals(undescores): 5738
byte literal           : 0
catch in finally       : 35
elvis                  : 600  --> correct value ?
instanceof switch      : 159
loop with remove       : 88  --> correct value 430
multi catch            : 39
object switch          : 379
rethrow clause         : 859
string in switch       : 117
Files:5822

Sub part 1 (code generated beans):
all catchs             : 753
all conditionals       : 10244
all ifs                : 4955
all integer literals   : 145405
big integer literals(undescores) : 25957
byte literal           : 0
catch in finally       : 0
elvis                  : 4058  --> correct value, probably 0
instanceof switch      : 9
loop with remove       : 0  --> correct value 0
multi catch            : 0
object switch          : 15
rethrow clause         : 1
string in switch       : 0
Files:1553

Sub part 2 (presentation layer):
all catchs             : 370
all conditionals       : 366
all ifs                : 1622
all integer literals   : 2632
big integer literals(undescores) : 39
byte literal           : 0
catch in finally       : 6
elvis                  : 33
instanceof switch      : 47
loop with remove       : 8  --> correct value 20
multi catch            : 0
object switch          : 112
rethrow clause         : 61
string in switch       : 35
Files:1160

 while \(.+?\.hasNext\(\)\)
all hasNext() while    : 256
 for \(Iterator
all iterator() for     : 536
 for \(int
all int for            : 4530 *not all loops around lists
 for \(
all for                : 8248 *not all loops around lists

Elvis-conditional = ?/2185 =
Loop-with-remove  = 450/8248 = 5.5%
Multi-catch  = 39/3715 = 1.0%


The Elvis number currently needs manual work to calculate, so I passed
for the size of the main sourcebase. However, 12% of all conditionals
in the low level library is a reasonable number of hits.

The loop-with-remove is between 5 and 5.5% (of all loops, which
includes loops around things other than lists, like strings). I can't
easily determine how often the loop index is needed, or whether it is
the first/last loop, each of which would push up the %age.

Multi-catch has about 1% of all catch statements in the main
E-Commerce, but 5.6% in the low level libraries. This perhaps
indicates where the sweet spot for the feature is - libraries and
frameworks.

Stephen