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I think if we remember to how this thread originated, it would
be useful to get a general concencus that use of attributes depends on what you
are doing.
We started discussing XML RPC and wire technologies using XML,
such as SOAP. These do not implement *any* kind of compression, so the use of
attributes is advantageous for (more) efficient communication.
Where compression is used it seems (from what I have seen
anyway) that it is not all that important what you use.
Rgds,
Steven
Steven Livingstone
Glasgow, Scotland.
+44 7771 957 280
----- Original Message -----
Sent: Wednesday, September 22, 1999 7:19
PM
Subject: RE: RFC: Attributes and
XML-RPC
These results are consistent with tests that I have
run against actual XML files generated from databases. After compression, there is little difference
between different syntactic families.
At 12:16 PM 09/22/99 -0400,
Hunter, David wrote:
So even if you
compress the files, the
attribute version will be able to compress to 50%
smaller than the
other file. Again, 2KB isn't a lot, but if we're
talking
megabytes in size, 50% is a lot.
I wrote a quick
perl script to take /usr/dict/words and turn it into an XML file, with some
artificially generated "attributes". In the resulting file named
attrib.xml, each <word> tag contains the additional information as
attributes. I did the same thing to produce a file called child.xml,
except that the additional information is presented as a child element
instead of as an attribute. Here are the results:
$
./make.pl
$ ls -l
total 13004
-rw-rw-r-- 1
mnutter mnutter 5811852 Sep 22 13:16
attrib.xml
-rw-rw-r-- 1 mnutter mnutter
7445892 Sep 22 13:16 child.xml
-rwxr-xr-x 1 mnutter
mnutter 976 Sep 22 13:16 make.pl
$
gzip attrib.xml
$ gzip child.xml
$ ls -l
total
1127
-rw-rw-r-- 1 mnutter mnutter
671039 Sep 22 13:16 attrib.xml.gz
-rw-rw-r-- 1 mnutter
mnutter 472394 Sep 22 13:16
child.xml.gz
-rwxr-xr-x 1 mnutter
mnutter 976 Sep 22 13:16
make.pl
I used gzip as an example of off-the-shelf compression
technology. As you can see, even though the raw child.xml file is
larger, the compressed version is *smaller* than the corresponding
implementation with attributes.
This may not be true in all cases, of
course, but I expect it often will, due to the way such compression
algorithms work.
For your reference, here is the Perl script I used
to create the two files:
open WORDS, "</usr/dict/words" or die
"Couldn't open dictionary.\n";
open ATTRIB, ">attrib.xml" or die
"Couldn't open attrib.xml\n";
open CHILD, ">child.xml" or die
"Couldn't open child.xml\n";
@twenty_strings = qw(one two three four
five six seven eight nine
ten
eleven twelve thirteen fourteen fifteen
sixteen
seventeen eighteen nineteen twenty);
print ATTRIB
"<attrib>\n";
print CHILD "<child>\n";
while($word =
<WORDS>)
{
$time =
time();
$timestr =
localtime($time);
$twenty = rand %
20;
$twentystr =
$twenty_strings[$twenty];
print ATTRIB
<<EOM;
<word time="$time" timestr="$timestr"
twenty="$twenty"
twentystr="$twentystr">$word</word>
EOM
print CHILD <<EOM;
<word>
<time>$time</time>
<timestr>$timestr</timestr>
<twenty>$twenty</twenty>
<twentystr>$twentystr</twentystr>
</word>
EOM
}
print ATTRIB "</attrib>\n";
print
CHILD "</child>\n";
close CHILD;
close ATTRIB;
close
WORDS;
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
Mark Nutter, <mnutter@fore.com>
Internet Applications Developer
FORE Systems
Some people are atheists 'til the day they
die.
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