Question

I have an application which will store a series of (float) values in an XML file. There could be upwards of 100,000 values so I am interested in keeping the size down, but I also want files to be readily accessible by third parties.

There seem to be various methods open to me as far as encoding the data within the XML:

1.

<data>
  <value>12.34</value>
  <value>56.78</value>
  ...
  <value>90.12</value>
</data>

2.

<data>
  <value v="12.34"/>
  <value v="56.78"/>
  ...
  <value v="90.12"/>
</data> 

3.

<data>12.34
56.78
  ...
90.12
</data> 

4.

<data>12.34, 56.78, ... 90.12</data> 

and there are probably more variations as well.

I’m just curious to know the drawbacks (if any) to each of these approaches. Some may not be compliant for example.

Answer 1

I don’t think there’s a “better” way of doing it. Read my comment above for alternatives. But if you’re hooked on XML, then go with whatever works for you. I personally prefer something like this

<data>
   <item key="somekey1" value="somevalue1" />
   <item key="somekey2" value="somevalue2" />
   <item key="somekey3" value="somevalue3" />
</data>

Simply because it’s nice and easy to read, and keeps the tags smaller.

EDIT:

Remember, the fewer characters are in your XML, the smaller it will be. (again, why I suggest JSON), so if you can get it nice and tight, by all means do it.

<d>
   <i k="somekey1" v="somevalue1" />
   <i k="somekey2" v="somevalue2" />
   <i k="somekey3" v="somevalue3" />
</d>

EDIT:

Also, I know you didn’t ask, but I thought I’d show you what JSON would look like

   [{ "key": "somevalue1", "value": "somevalue1"},
    { "key": "somevalue2", "value": "somevalue2"}]