Files
tippecanoe/evaluator.hpp
T
Erica FischerandCursor 65beb3f0d7 Migrate jsonpull to unique_ptr ownership
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>
2026-05-30 20:44:25 -07:00

21 lines
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C++

#ifndef EVALUATOR_HPP
#define EVALUATOR HPP
#include <unordered_map>
#include <string>
#include <set>
#include "jsonpull/jsonpull.h"
#include "mvt.hpp"
// The `filter` parameters take a borrowed pointer; the caller (in
// main.cpp, tile-join, overzoom) keeps the json_object_ptr alive
// across every per-feature evaluate() call. A raw pointer avoids
// touching unique_ptr at all on this hot path.
bool evaluate(std::unordered_map<std::string, mvt_value> const &feature, std::string const &layer, json_object *filter, std::set<std::string> &exclude_attributes, std::vector<std::string> const &unidecode_data);
json_object_ptr parse_filter(const char *s);
json_object_ptr read_filter(const char *fname);
bool evaluate(mvt_feature const &feat, mvt_layer const &layer, json_object *filter, std::set<std::string> &exclude_attributes, int z, std::vector<std::string> const &unidecode_data);
#endif