Factor out the GeoJSON parsing loop from feature serialization

2026-10-02 16:35:40 +02:00 · 2018-08-08 13:11:10 -07:00
parent 2e80377b24
commit 79363e397b
5 changed files with 189 additions and 122 deletions
@@ -0,0 +1,155 @@
+#ifdef MTRACE
+#include <mcheck.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <errno.h>
+#include "geojson-loop.hpp"
+#include "jsonpull/jsonpull.h"
+
+// XXX duplicated
+#define GEOM_TYPES 6
+static const char *geometry_names[GEOM_TYPES] = {
+	"Point", "MultiPoint", "LineString", "MultiLineString", "Polygon", "MultiPolygon",
+};
+
+// XXX duplicated
+static void json_context(json_object *j) {
+	char *s = json_stringify(j);
+
+	if (strlen(s) >= 500) {
+		sprintf(s + 497, "...");
+	}
+
+	fprintf(stderr, "In JSON object %s\n", s);
+	free(s);  // stringify
+}
+
+void parse_json(json_feature_action *jfa, json_pull *jp) {
+	long long found_hashes = 0;
+	long long found_features = 0;
+	long long found_geometries = 0;
+
+	while (1) {
+		json_object *j = json_read(jp);
+		if (j == NULL) {
+			if (jp->error != NULL) {
+				fprintf(stderr, "%s:%d: %s\n", jfa->fname.c_str(), jp->line, jp->error);
+				if (jp->root != NULL) {
+					json_context(jp->root);
+				}
+			}
+
+			json_free(jp->root);
+			break;
+		}
+
+		if (j->type == JSON_HASH) {
+			found_hashes++;
+
+			if (found_hashes == 50 && found_features == 0 && found_geometries == 0) {
+				fprintf(stderr, "%s:%d: Warning: not finding any GeoJSON features or geometries in input yet after 50 objects.\n", jfa->fname.c_str(), jp->line);
+			}
+		}
+
+		json_object *type = json_hash_get(j, "type");
+		if (type == NULL || type->type != JSON_STRING) {
+			continue;
+		}
+
+		if (found_features == 0) {
+			int i;
+			int is_geometry = 0;
+			for (i = 0; i < GEOM_TYPES; i++) {
+				if (strcmp(type->string, geometry_names[i]) == 0) {
+					is_geometry = 1;
+					break;
+				}
+			}
+
+			if (is_geometry) {
+				if (j->parent != NULL) {
+					if (j->parent->type == JSON_ARRAY && j->parent->parent != NULL) {
+						if (j->parent->parent->type == JSON_HASH) {
+							json_object *geometries = json_hash_get(j->parent->parent, "geometries");
+							if (geometries != NULL) {
+								// Parent of Parent must be a GeometryCollection
+								is_geometry = 0;
+							}
+						}
+					} else if (j->parent->type == JSON_HASH) {
+						json_object *geometry = json_hash_get(j->parent, "geometry");
+						if (geometry != NULL) {
+							// Parent must be a Feature
+							is_geometry = 0;
+						}
+					}
+				}
+			}
+
+			if (is_geometry) {
+				if (found_features != 0 && found_geometries == 0) {
+					fprintf(stderr, "%s:%d: Warning: found a mixture of features and bare geometries\n", jfa->fname.c_str(), jp->line);
+				}
+				found_geometries++;
+
+				jfa->add_feature(j, NULL, NULL, NULL, j);
+				json_free(j);
+				continue;
+			}
+		}
+
+		if (strcmp(type->string, "Feature") != 0) {
+			if (strcmp(type->string, "FeatureCollection") == 0) {
+				jfa->check_crs(j);
+				json_free(j);
+			}
+
+			continue;
+		}
+
+		if (found_features == 0 && found_geometries != 0) {
+			fprintf(stderr, "%s:%d: Warning: found a mixture of features and bare geometries\n", jfa->fname.c_str(), jp->line);
+		}
+		found_features++;
+
+		json_object *geometry = json_hash_get(j, "geometry");
+		if (geometry == NULL) {
+			fprintf(stderr, "%s:%d: feature with no geometry\n", jfa->fname.c_str(), jp->line);
+			json_context(j);
+			json_free(j);
+			continue;
+		}
+
+		json_object *properties = json_hash_get(j, "properties");
+		if (properties == NULL || (properties->type != JSON_HASH && properties->type != JSON_NULL)) {
+			fprintf(stderr, "%s:%d: feature without properties hash\n", jfa->fname.c_str(), jp->line);
+			json_context(j);
+			json_free(j);
+			continue;
+		}
+
+		json_object *tippecanoe = json_hash_get(j, "tippecanoe");
+		json_object *id = json_hash_get(j, "id");
+
+		json_object *geometries = json_hash_get(geometry, "geometries");
+		if (geometries != NULL && geometries->type == JSON_ARRAY) {
+			size_t g;
+			for (g = 0; g < geometries->length; g++) {
+				jfa->add_feature(geometries->array[g], properties, id, tippecanoe, j);
+			}
+		} else {
+			jfa->add_feature(geometry, properties, id, tippecanoe, j);
+		}
+
+		json_free(j);
+
+		/* XXX check for any non-features in the outer object */
+	}
+}