Put extra requested fields into different cache files

From: Liping Ke <[email protected]>

Below four patches are for putting extra requested fields inito different cache files instead of using only on bb_cache.dat. Now image creator need extra three fields. And in the future, there might be more similar requests. For each extra requestor, we will save the requested fields data into a separate cache files so that those who don't need it will not be impacted with larger fields and large data files.

Pull URL: git://git.pokylinux.org/poky-contrib.git
Branch: lke/cache_impl
Browse: http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=lke/cache_impl

Thanks,
Liping Ke <[email protected]>
---

Liping Ke (4):
This patch introduce new param bitbake_mode into Cache.py. This patch splits Cache Data Retrieve method from Data Fields. This patch introduces Extra required fields for image creator. This patch implements independent cache for Extra Cache Fields
Request

 bitbake/lib/bb/cache.py       |  161 ++++++++++++++++++++++++++++++++---------
 bitbake/lib/bb/cooker.py      |   55 ++++++++++----
 bitbake/lib/bb/extra_cache.py |   29 ++++++++
 3 files changed, 196 insertions(+), 49 deletions(-)
 create mode 100644 bitbake/lib/bb/extra_cache.py