Kai Krueger e8001c859f Add support for pluggable storage backends to mod_tile / renderd ...

So far, (meta)tiles could only be stored and retrieved from a locally mounted posix filesystem.  Although, the posix
filesystem API is it self a plugable storage layer into which one can mount many different filsystems, from temporary
filesystems to network filesystems, as mod_tile installations scale up to multi-server environments this might not be sufficient and one
may want to use other storage layers.

This patch therefore abstracts all storage calls out into a separate API that can be implemented by various storage backends to fit the needs of different
installations. 

Three storage backends are included in this commit:

- file backend: This is the equivalent of what existed before in mod_tile / renderd. This uses a posix filesystem to store (meta)tiles
- memcached: This stores tiles in a memcached store
- rados: This stores tiles in a rados / ceph cluster

The memcached and rados backends should currently still be considered as experimental

There are also other refactoring and cleanups in this commit

2013-03-23 22:19:30 +00:00

..

ac_check_icu.m4

[mod_tile] make libicu configurable if it is installed in a non-standard place

2012-01-22 19:07:04 +00:00

ax_lib_mapnik.m4

[mod_tile] improve autoconf detection of mapnik libraries

2012-01-22 06:26:01 +00:00

ax_libmemcached.m4

Add support for pluggable storage backends to mod_tile / renderd

2013-03-23 22:19:30 +00:00

ax_pthread.m4

use autoconf / automake to find libraries and make it more portable

2012-01-15 07:23:52 +00:00

ax_restore_flags.m4

Add support for pluggable storage backends to mod_tile / renderd

2013-03-23 22:19:30 +00:00

ax_save_flags.m4

Add support for pluggable storage backends to mod_tile / renderd

2013-03-23 22:19:30 +00:00

m4_ax_boost_base.m4

[mod_tile] improve autoconf settings to be more portable

2012-01-22 18:00:15 +00:00