By grepping the continuous integration errors log a number of GEORADIUS
tests failures were detected.
Fortunately when a GEORADIUS failure happens, the test suite logs enough
information in order to reproduce the problem: the PRNG seed,
coordinates and radius of the query.
By reproducing the issues, three different bugs were discovered and
fixed in this commit. This commit also improves the already good
reporting of the fuzzer and adds the failure vectors as regression
tests.
The issues found:
1. We need larger squares around the poles in order to cover the area
requested by the user. There were already checks in order to use a
smaller step (larger squares) but the limit set (+/- 67 degrees) is not
enough in certain edge cases, so 66 is used now.
2. Even near the equator, when the search area center is very near the
edge of the square, the north, south, west or ovest square may not be
able to fully cover the specified radius. Now a test is performed at the
edge of the initial guessed search area, and larger squares are used in
case the test fails.
3. Because of rounding errors between Redis and Tcl, sometimes the test
signaled false positives. This is now addressed.
Whenever possible the original code was improved a bit in other ways. A
debugging example stanza was added in order to make the next debugging
session simpler when the next bug is found.
Instead of successive divisions in iteration the new code uses bitwise
magic to interleave / deinterleave two 32bit values into a 64bit one.
All tests still passing and is measurably faster, so worth it.
The GIS standard and all the major DBs implementing GIS related
functions take coordinates as x,y that is longitude,latitude.
It was a bad start for Redis to do things differently, so even if this
means that existing users of the Geo module will be required to change
their code, Redis now conforms to the standard.
Usually Redis is very backward compatible, but this is not an exception
to this rule, since this is the first Geo implementation entering the
official Redis source code. It is not wise to try to be backward
compatible with code forks... :-)
Close#2637.
This commit simplifies the implementation in a few ways:
1. zsetScore implementation improved a bit and moved into t_zset.c where
is now also used to implement the ZSCORE command.
2. Range extraction from the sorted set remains a separated
implementation from the one in t_zset.c, but was hyper-specialized in
order to avoid accumulating results into a list and remove the ones
outside the radius.
3. A new type is introduced: geoArray, which can accumulate geoPoint
structures in a vector with power of two expansion policy. This is
useful since we have to call qsort() against it before returning the
result to the user.
4. As a result of 1, 2, 3, the two files zset.c and zset.h are now
removed, including the function to merge two lists (now handled with
functions that can add elements to existing geoArray arrays) and
the machinery used in order to pass zset results.
5. geoPoint structure simplified because of the general code structure
simplification, so we no longer need to take references to objects.
6. Not counting the JSON removal the refactoring removes 200 lines of
code for the same functionalities, with a simpler to read
implementation.
7. GEORADIUS is now 2.5 times faster testing with 10k elements and a
radius resulting in 124 elements returned. However this is mostly a
side effect of the refactoring and simplification. More speed gains
can be achieved by trying to optimize the code.
Current todo:
- replace functions in zset.{c,h} with a new unified Redis
zset access API.
Once we get the zset interface fixed, we can squash
relevant commits in this branch and have one nice commit
to merge into unstable.
This commit adds:
- Geo commands
- Tests; runnable with: ./runtest --single unit/geo
- Geo helpers in deps/geohash-int/
- src/geo.{c,h} and src/geojson.{c,h} implementing geo commands
- Updated build configurations to get everything working
- TEMPORARY: src/zset.{c,h} implementing zset score and zset
range reading without writing to client output buffers.
- Modified linkage of one t_zset.c function for use in zset.c
Conflicts:
src/Makefile
src/redis.c
