Provide an API to query which tiles are currently being synced. This
allows the higher levels (TileManager in FlightGear) to safely wait on
TerraSync before loading tiles.
Doing this exposed some bugs in scheduling tiles to sync by integer
lat/lon, related to round-towards-zero with -ve values (western /
souther hemispheres). To resolve these, and also reduce spurious
syncs, switch to an explicit API for requesting tiles by SGBucket.
This keeps TerraSync fully aligned with the TileManager queue, which
has many benefits for both high and low visibility situations.
Prefer existing, idle connections to creating new connections,
even when below the max-connection limit. Gives much better re-use
and pipeline-ing, and hence reduced setup time/trips.
When re-init-ing the sim, tell TerraSync what's going on (we don't want
to actually reset it, since that would disturb in-flight downloads).
Add an explicit method so it can reset its last lon/lat, and hence do
the initial sync at the new location correctly.
Track 'waiting for response' state explicitly, so we don't
falsely report IDLE when waiting for a response.
Expose bytes-per-second download rate as metric.
Add explicit subsystem state tracking so we can safely init()
terrasync very early during startup, and hence overlap lengthy operations
(Shared Models sync and initial NavCache build)
When using built-in sync code, separate items into distinct slots.
Slots process items sequentially, but each slot works in parallel (using
a single shared HTTP engine). This allows tiles to be synced in parallel
with airports/shared models data, greatly increasing responsiveness
to get tiles synced on initial launch.
We already synchronise other things besides tiles, and will soon want different
behaviour based on the type of item we're syncing (so we can synchronize some items in parallel). Rename the struct to be clearer, and add an enum encoding the type of item for future use.
Hopefully this tells the Expat headers not to do any clever
declspec(import) or export stuff, which we don't want since we only
use the symbols within SimGearCore, and don't export them.
Switch back to including the bundled expat sources directly in the
targets, since transitive linking of static libs is very awkward.
Makes static build happy again (let's see what else breaks)
Renamed bundled Expat headers to avoid any
possibility of accidental including system headers when
using bundled Expat, or vice-versa. Should help with SVN
crashes reported by Thomas.
Make the already present cache of updated URLs persistent, with a
definable lifetime, currently 24 hours. This ensures terrasync-ed
resources are checked less often (max once per day) instead of each
FGFS launch, which should greatly cut down requests to the backend.
- max connections limit, and parallel connections to a single host where possible.
(Will permit updating terrain and Models / Airports / data in parallel)
- add LGPL headers
- give HTTP::Client a private impl class, to keep header simple.
Slightly simplistic, but definitiely correct, method
for ensuring singleton creation is threadsafe. Can
be optimised if lock contention is ever an issue.
If setting properties on a group a check is performed if
this property exists on any possible child element, and
only if this is the case the property is stored in the
groups style.
Previously elements have been only initialized during
their first usage, leading to ignored styles if they
have been set on a parent element before instantiating
an instance of the actual element type.
