Fix 0 capacity issue. now cache_size can be 0

[wuarmin]

I encountered a problem while setting cache_size to 0. The result was an unlimited cache because in python "0" evaluates to false. This PR would fix this.

kind regards

[wuarmin]

@msiemens Do you know why the test-build with Python 2.6 failed?

[msiemens]

Thanks for the Pull Request! 🙂

@msiemens Do you know why the test-build with Python 2.6 failed?

This is due to #185 where it's still up to debate whether or not to drop Python 2.6 as our test infrastructure has dropped support for it.

[wuarmin]

@msiemens All right. I 'll provide another to provide the option to disable cache explicitly. (We talked about it at #179 )

[msiemens]

Actually, I'm just thinking about if the best way to disable the query cache would be to actually use a cache_size of 0 and in this case skip the query cache logic or replace the cache with an class that has the same interface/api but doesn't perform any caching. This may make the API a little less nosiy compared to adding a new argument – if we document this properly. What do you think?

[wuarmin]

@msiemens Yes, I think you are right. Defining a cache_size of zero, fullfills the purpose. Another option is not necessary.

[msiemens]

This is now released in v3.8.0 🙂

[wuarmin]

@msiemens
great!
The latest version in python package index is still 3.7.0.
If I want to upgrade I get following message:

CRITICAL:pip.index:Could not find a version that satisfies the requirement tinydb==3.8.0 (from versions: 1.0.0, 1.0.1, 1.1.0, 1.1.1, 1.2.0, 1.3.0, 1.4.0, 2.0.0, 2.0.1, 2.1.0, 2.2.0, 2.2.1, 2.2.2, 2.3.0b0, 2.3.1, 2.3.1.post1, 2.3.1.post2, 2.3.2, 2.4, 3.0.0, 3.1.0, 3.1.1, 3.1.2, 3.1.3, 3.2.0, 3.2.1, 3.2.2, 3.2.3, 3.3.0, 3.3.1, 3.4.0, 3.4.1, 3.5.0, 3.6.0, 3.7.0)

[msiemens]

Whoops! Forgot to publish it on PyPI, sorry! Should work now 🙂

[wuarmin]

thanks! 👍 I'm on 3.8.0 😄