This was an extra level of attribute indirection (features point
to metadata records which point to key and value strings) which was
intended to reduce the size of temporary storage for features with
large numbers of attributes that were also spread across large numbers
of tiles at maxzoom.
For other kinds of features, the extra indirection slowed things down
instead, and, especially when maxzoom guessing was being used, many more
features were having their metadata externalized than could actually
benefit from it.
* Stop adding features to a tile if it can't possibly work
* Add --integer and --fraction options to tippecanoe-decode
* Carry the strategies field from tileset metadata through tile-join
* Update changelog
* Assign different codes to different kinds of error exits
* Change JSON objects to a union type to use less memory
* Stop storing the string representation of JSON numbers
* Restore the ability to create features with large integer attributes
* Make sure large-integer feature IDs still behave as before
* Add missing #include
* Don't preallocate as much space for arrays and objects
* Treat inability to check free disk space as a warning, not an error
* Update changelog and version
Now the count is always adjacent to whereever the key/value pair is
stored, and is not kept in the serial feature object other than as
the length of the vectors of keys and values.
The first feature in a tile can never be dropped, since there is
no previous feature to attach its properties to.
Remove the previous special case that reset the dropping counter
at the first feature within each tile proper (as opposed to the
first feature in each tile, including its buffer, which is now
the one that is guaranteed to be preserved).
(The feature count when filtering will be the sum of features
across tiles instead of filters from the original input, since
the filter reader doesn't know what the original input feature
set was.)
Erica Fischer