Comments were 25% of the added lines, and the ownership model was spelled
out in five places. Collect it into one block at the top of jsonpull.h and
point at it from the rest, cutting the ratio to 14% and the total by about
200 lines.
Removed the duplicate explanations of the deleter dispatch, of what detach
does to the back-pointers, and of "json_read returns intermediate
containers, do not free them". Trimmed the comments that argued for a
choice rather than described the code -- the reserve(2) / reserve(4)
rationales, the string-buffer copy, the pmtiles check ordering -- to a line
each, and shortened the test preambles, keeping the parts that say why a
test is shaped the way it is.
No code changes; the test suite is unchanged in both configurations.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017KNxyHKasyWrWcvre2yK4r
Replaces the shared_ptr-based json_object_ptr with a unique_ptr that
has a stateless custom deleter dispatching on json_object::type before
calling the right subclass destructor. Eliminates per-node atomic
reference-counting and the control-block allocation that shared_ptr
required for every node in the tree.
API now distinguishes owning and borrowing pointers explicitly:
- json_read / json_read_separators / json_hash_get return raw
json_object * (borrowed from the parser-owned tree).
- json_read_tree / json_disconnect return json_object_ptr (caller
takes ownership; back-pointers are cleared so the subtree can
outlive the parser).
- json_free / json_context / json_stringify take raw pointers.
- The parser's container_stack holds raw pointers; jp->root keeps
unique_ptr ownership of the most recent top-level value.
Internally, take_from_owner moves the unique_ptr out of whichever
parent vector / hash entry / parser root owned it, which both
json_free and json_disconnect rely on.
In the streaming parsers (parse_feature, parse_layers, the
geojson-loop callback), we are careful to free `j` only after we
have processed a complete Feature: json_read returns each token
as the tree is being built up, and freeing an intermediate node
would splice it out of the surrounding hash and corrupt the
in-progress feature.
Benchmark (tl_2022_us_county.json, -z0 --extend-zooms-if-still-dropping,
median of 5 runs on macOS arm64): 8.5s, vs 10.6s with shared_ptr
and 8.7s on the pre-refactor C baseline.
Co-authored-by: Cursor <cursoragent@cursor.com>
Replace the parallel std::vector<json_object_ptr> keys / values on
json_hash with a single std::vector<json_entry>, where json_entry is
a small {key, value} aggregate. This still preserves insertion order
(the property the parallel vectors were providing) but removes the
"keep two vectors in lockstep" pattern, and call sites can now use
range-for with structured bindings:
for (auto &[k, v] : o->entries()) { ... }
Side effects:
* sizeof(json_hash) drops from 72 to 48 bytes (one fewer vector
header), matching json_array.
* The keys() and values() accessors on json_object are replaced by a
single entries() accessor returning std::vector<json_entry>&.
* All call sites were swept from the old paired-index pattern
(`o->keys()[i]` / `o->values()[i]`) to entry-based access. Where the
original pattern relied on `nprop = 0` to short-circuit iteration on
a null or non-hash `properties`, the rewrite now guards the loop
explicitly with `if (o->type == JSON_HASH)` so that calling
entries() doesn't trip the asserting downcast.
Co-authored-by: Cursor <cursoragent@cursor.com>
The previous "every member in a struct" layout cost 168 bytes per
json_object, even for JSON_NULL / JSON_TRUE / JSON_FALSE nodes that
have no payload. Splitting json_object into a small base class plus
json_number / json_string / json_array / json_hash subclasses brings
each instance down to just the size of its actual contents:
json_object (base, TRUE / FALSE / NULL) 24 bytes
json_number 48 bytes
json_string 48 bytes
json_array (empty) 48 bytes
json_hash (empty) 72 bytes
Other size wins along the way:
* Drop enable_shared_from_this<json_object> (its embedded weak_ptr
was 16 bytes per node). json_pull now keeps an explicit
container_stack and the parser no longer needs to resurrect a
shared_ptr from a raw `parent` walk.
* Remove the unused `refcon` slot from the string variant.
* No virtual destructor: shared_ptr keeps the deleter from the
original std::make_shared<json_xxx> call, so destroying a
shared_ptr<json_object> still runs the right subclass dtor.
The base class exposes type-tagged accessors (o->string(),
o->number(), o->array(), o->keys(), o->values(), o->large_signed(),
o->large_unsigned()) that assert the type matches and downcast to
the appropriate subclass storage. All call sites were swept from
the old `o->value.X.Y` field paths to these accessors. A raw-pointer
overload of json_hash_get() replaces the few external uses of
shared_from_this() that survived in geojson-loop.cpp.
Co-authored-by: Cursor <cursoragent@cursor.com>
Replace the manual malloc/realloc/free memory management in jsonpull
with std::shared_ptr ownership. Each json_object now owns its children
through std::vector<json_object_ptr>; raw back-pointers to parent and
parser remain valid by structural invariant and are cleared on
json_disconnect so detached subtrees can outlive their parser.
Strings become std::string, child arrays become std::vector, and the
old union becomes a struct so non-trivial members can coexist while
preserving the existing o->value.xxx access paths.
The old jsonpull.c is replaced by jsonpull.cpp, json_stringify now
returns std::string, and all callers across tippecanoe, tile-join,
tippecanoe-decode, tippecanoe-json-tool, tippecanoe-overzoom and the
unit tests are updated to use json_object_ptr / json_pull_ptr.
Co-authored-by: Cursor <cursoragent@cursor.com>
* Plumb a clip bounding box around through overzoom
* Actually do some clipping
* Add a test
* Fix post-binning clipping
* Factoring out geometry parsing from feature parsing
* Accept a clip polygon argument to tippecanoe-overzoom
* Progress in the direction of polygon clipping
* Fix the wagyu flags. We need intersection, not union
* Remove debug spew
* Clip points to polygon bounds too
* Copy the geometric binning code to serve as intersection-finding code
* Add clipper2 for linestring clipping
* Compiles, but does not actually seem to clip. Hmm.
* Oh, it helps if I actually call the function
* Add clipping tests
* Add missing fixture, and don't crash if it is missing
* Remember to do polygon clipping after binning too
* Fix scaling before post-binning clipping. Add test.
* Remove unused parts of clipper
* Rename for consistency
* Revert accidentally added line
* Clip the clip regions to the tile bounds to reduce their complexity
* Add a test of clipping the clip region down to the tile boundary
* Update version and changelog
* Another try at fixing longitude wraparound for bins
* Gonna get it right this time
* Forgot to update the comment
* The filter case was not supposed to reinterpret geometry
* Copy antimeridian-crossing geometries to the other side too
* Getting closer to getting antimeridian-crossing polygons right
* Update changelog and version
* Factoring out tilestats management from GeoJSON file reading
* Move code around so overzoom can link against parse_layers
* Read the file of bins
* Plumb the bins through to overzoom()
* Some zip code bins to test with
* (Currently non-functional) test of binning
* Starting to spell out the bin matching loop
* Can't flatten points, so don't flatten bins either
* More fleshing out bin traversal
* Bounding box of tile-relative mvt geometry
* Smallest enclosing tile from bbox
* Most of the bin scan
* Add point in polygon check. It crashes.
* Find the matching bins
* GDAL-style bounding boxes have eaten my brain
* Make some features to bin into
* Increment a count as features are found to be within the bins
* Fix longitude wraparound in overzoom bins
* Fix the tests
* Push off attribute copying until after bin assignment
* Carry sum of numeric attributes into the bins
* Also add mean, min, and max
* Add --calculate-feature-index since I keep needing it for testing
* Add an option to accumulate sum/mean/max/min/count of all numeric attrs
* Don't bake in tippecanoe:mean, since we redo it from sum and count
* Forgot to update this test fixture after removing tiled mean
* Update version and changelog
* Add a way to run tippecanoe single-threaded for profiling
* Do less work when the tilestats sample values list is already full
* Save a copy when retrieving the attribute key
* Fewer atomic operations
* Move string hashing from mbtiles to text
* Only do approximate attribute deduplication when writing tiles
* Feature dropping tests are sensitive to exact tile size
* All tile creators now create a string pool for the tile
* Features clipped away to nothing should not participate in that tile
* Revert "Only do approximate attribute deduplication when writing tiles"
This reverts commit c42b34b498.
* Also revert the related test changes
* Revert "Revert "Only do approximate attribute deduplication when writing tiles""
This reverts commit 18509876c3.
* Be more specific about the string hash function
* Use fnv1a instead of std::hash for everything
* Reduce the chance of hash collisions
* Stick a hash search on the front of the tree search in addpool
* Eliminate repeated hashing of the same string
* Switch instead of ifs in json parsing
* A few more cases to populate the hash in addpool
* Store the hash in the tree instead of recalculating
* Add explanatory comment for mysterious argument
* Fewer copies in attribute stringification
* Clean up ancient weirdness in JSON attribute stringification
* More serial_val cleanup
* Pass a serial_feature to rewrite instead of many broken-down arguments
* Get rid of the multiple geometries within `partial`
* Revert "Pass a serial_feature to rewrite instead of many broken-down arguments"
This reverts commit 6f4ab9b725.
* Goodbye, struct coalesce
* Revert "Features clipped away to nothing should not participate in that tile"
This reverts commit 124462fbdc.
* Migrating fields from partial to serial_feature
* Name reconciliation between serial_feature and partial
* Replace struct partial with an augmented serial_feature
* Fix some overzealous search-and-replace renaming
* Don't say struct so often
* Remove more of the former partial construction
* Commenting and cleaning up
* Trying again to avoid all these arguments to rewrite
* I swear I did this same thing before and it didn't work.
* More rewrite cleanup
* Exile --detect-shared-borders to its own file
* Add missing headers
* More commenting and cleanup
* More comments
* Sprinkle consts around
* Emplacing and std::moving
* More cleanup
* That shouldn't have worked after a std::move
* Don't need to allocate memory to compare keys
* Reduce use of the global string pool in tiling
* Another avoidable mvt_value construction
* Further reduction to explicit string pool passing
* These reverses are no longer optimizations
* These layernames can all be references
* Don't drag an unused layername string around with every feature
* Heed a compiler warning about potential buffer overflow
* Fix my confusion about which feature's string pool is relevant
* Avoid some unnecessary allocations in attribute accumulation
* Maybe faster serialization?
* Eliminate a comparison
* Do the same here
* Save a couple of allocations when parsing numbers in JSON
* Immediately assign features to layers instead of subdividing later
* Maintain tilestats for tippecanoe:retain_points_multiplier_sequence
* Crunch out more duplicate attribute values when writing out the tile
* Do tilestats for tippecanoe:retain_points_multiplier_first too
* Shell filters need to be real threads, even if nothing else does
* Simplify tippecanoe_minzoom/maxzoom representation
* Update version and changelog
* Make feature ordering cooperate with --retain-points-multiplier
* Forgot to check in the actual code changes???
* Sort within each multiplier cluster as well as between clusters
* Correct description of behavior in changelog
* Drag original feature sequence along in megatiles for post-filter sort
* Plumb the preserve-input-order flag through overzoom
* Sort in overzoom if requested
* Use within-tile input sequence numbers, not global sequence numbers
* Documentation
* Reverse direction of search to prevent accidental skipping
* Add some comments about converting between attribute representations
* Turn off unit, which has bit-rotted
* Instrument line simplification
* Do more work in integer space
* Update tests with simplification done with more integers
* Clean up
* Update changelog
* Eradicate calls to deprecated sprintf()
* Revert "Turn off unit, which has bit-rotted"
This reverts commit 998779313f.
* Fix catch by switching to an unsigned type
* 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
Claude