tippecanoe/attribute.cpp

#include <string>
#include <unordered_map>
#include "attribute.hpp"
#include "errors.hpp"
#include "serial.hpp"
#include "jsonpull/jsonpull.h"
#include "milo/dtoa_milo.h"
#include "raii.hpp"

std::map<std::string, attribute_op> numeric_operations = {
	{"sum", op_sum},
	{"min", op_min},
	{"max", op_max},
	{"count", op_count},
};

void set_attribute_accum(std::unordered_map<std::string, attribute_op> &attribute_accum, std::string name, std::string type) {
	attribute_op t;

	if (type == "sum") {
		t = op_sum;
	} else if (type == "product") {
		t = op_product;
	} else if (type == "mean") {
		t = op_mean;
	} else if (type == "max") {
		t = op_max;
	} else if (type == "min") {
		t = op_min;
	} else if (type == "concat") {
		t = op_concat;
	} else if (type == "comma") {
		t = op_comma;
	} else if (type == "count") {
		t = op_count;
	} else {
		throw_tippecanoe_error(EXIT_ARGS, "Attribute method (%s) must be sum, product, mean, max, min, concat, comma, or count", type.c_str());
	}

	attribute_accum.insert(std::pair<std::string, attribute_op>(name, t));
}

void set_attribute_accum(std::unordered_map<std::string, attribute_op> &attribute_accum, const char *arg, char **argv) {
	if (*arg == '{') {
		unique_json_pull jp(json_begin_string(arg));
		json_object *o = json_read_tree(jp.get());

		if (o == NULL) {
			throw_tippecanoe_error(EXIT_JSON, "%s: -E%s: %s", *argv, arg, jp->error);
		}

		if (o->type != JSON_HASH) {
			throw_tippecanoe_error(EXIT_JSON, "%s: -E%s: not a JSON object", *argv, arg);
		}

		for (size_t i = 0; i < o->value.object.length; i++) {
			json_object *k = o->value.object.keys[i];
			json_object *v = o->value.object.values[i];

			if (k->type != JSON_STRING) {
				throw_tippecanoe_error(EXIT_JSON, "%s: -E%s: key %zu not a string", *argv, arg, i);
			}
			if (v->type != JSON_STRING) {
				throw_tippecanoe_error(EXIT_JSON, "%s: -E%s: value %zu not a string", *argv, arg, i);
			}

			set_attribute_accum(attribute_accum, k->value.string.string, v->value.string.string);
		}

		json_free(o);
		return;
	}

	const char *s = strchr(arg, ':');
	if (s == NULL) {
		throw_tippecanoe_error(EXIT_ARGS, "-E%s option must be in the form -Ename:method", arg);
	}

	std::string name = std::string(arg, s - arg);
	std::string type = std::string(s + 1);

	set_attribute_accum(attribute_accum, name, type);
}

template <class T>
static void preserve_attribute1(attribute_op const &op, std::string const &key, T const &val, std::vector<std::shared_ptr<std::string>> &full_keys, std::vector<T> &full_values, key_pool &key_pool) {
	for (size_t i = 0; i < full_keys.size(); i++) {
		if (key == *full_keys[i]) {
			switch (op) {
			case op_sum:
				full_values[i] = (full_values[i].to_double() + val.to_double());
				return;

			case op_product:
				full_values[i] = (full_values[i].to_double() * val.to_double());
				return;

			case op_max: {
				double existing = full_values[i].to_double();
				double maybe = val.to_double();
				if (maybe > existing) {
					full_values[i] = val;
				}
				return;
			}

			case op_min: {
				double existing = full_values[i].to_double();
				double maybe = val.to_double();
				if (maybe < existing) {
					full_values[i] = val;
				}
				return;
			}

			case op_mean: {
				size_t count = full_values[i].get_count();
				if (count <= 1) {
					full_values[i].set_double_count((full_values[i].to_double() + val.to_double()) / 2, 2);
				} else {
					double sum = full_values[i].to_double() * count + val.to_double();
					count++;
					full_values[i].set_double_count(sum / count, count);
				}
				return;
			}

			case op_concat:
				full_values[i].set_string_value(full_values[i].get_string_value() + val.get_string_value());
				return;

			case op_comma:
				full_values[i].set_string_value(full_values[i].get_string_value() + "," + val.get_string_value());
				return;

			case op_count: {
				size_t count = full_values[i].get_count();
				if (count <= 1) {
					full_values[i].set_double_count(2, 2);
				} else {
					full_values[i].set_double_count(count + 1, count + 1);
				}
				return;
			}
			}
		}
	}

	// not found, so we are making a new value

	T v;
	switch (op) {
	case op_sum:
	case op_max:
	case op_min:
		v = val;
		break;

	case op_count:
		v.set_double_count(1, 1);
		break;

	case op_mean:
		v.set_double_count(val.to_double(), 1);
		break;

	default:
		throw_tippecanoe_error(EXIT_IMPOSSIBLE, "can't happen: operation that isn't used by --accumulate-numeric-attributes");
	}

	full_keys.push_back(key_pool.pool(key));
	full_values.push_back(v);
}

void preserve_attribute(attribute_op const &op, std::string const &key, mvt_value const &val, std::vector<std::shared_ptr<std::string>> &full_keys, std::vector<mvt_value> &full_values, key_pool &key_pool) {
	preserve_attribute1(op, key, val, full_keys, full_values, key_pool);
}

void preserve_attribute(attribute_op const &op, std::string const &key, serial_val const &val, std::vector<std::shared_ptr<std::string>> &full_keys, std::vector<serial_val> &full_values, key_pool &key_pool) {
	preserve_attribute1(op, key, val, full_keys, full_values, key_pool);
}