Mostly just eliminating concatenation-reassignments by chaining
concatenations, reordering assignments to allow better use of bin.pack,
and using tables to store intermediate results before concatenating
them. Used strbuf as a quick fix in dhcp.lua. Eliminated some unused
string variables in vulns.lua.
Using this regular expression, '\(\w*\)\s*=\s*\1\s*\.\.', found and
replaced many string concatenation-reassignments. These can cause
performance issues, since a new string gets allocated for each
reassignment. In many cases, the replacement is simply a single string,
wrapped across lines with the '\z' escape, which consumes a newline and
whitespace following it. In other cases, a table is used to hold the
substrings until the final string is built with a single table.concat
operation (same technique used in stdnse.strbuf).
Also, some string-building loops of this form:
s = ""
for i = 1, 100, 1 do
s = s .. "\0"
end
were replaced with this much faster and cleaner version:
s = string.rep("\0", 100)
socket:connect(host.ip, port.number)
socket:connect(host.ip, port.number, port.protocol)
to this:
socket:connect(host, port)
connect can take host and port tables now, and the default protocol is
taken from the port table if possible.
