libcruft-util/json/schema.cpp

608 lines
16 KiB
C++

/*
* This file is part of libgim.
*
* libgim is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* libgim is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2012 Danny Robson <danny@nerdcruft.net>
*/
#include "../json.hpp"
#include "../debug.hpp"
#include "../maths.hpp"
#include <cmath>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <regex>
#include <boost/filesystem.hpp>
using namespace std;
using namespace std::placeholders;
enum {
ARG_COMMAND,
ARG_SCHEMA,
ARG_INPUT,
NUM_ARGS
};
void
print_usage (int argc, char **argv) {
if (argc <= ARG_COMMAND)
abort ();
std::cerr << "Usage: " << argv[ARG_COMMAND] << " <schema> <input>\n";
}
const char*
type_to_string (const json::node &node) {
if (node.is_array ()) return "array";
if (node.is_boolean ()) return "boolean";
if (node.is_null ()) return "null";
if (node.is_number ()) return "number";
if (node.is_object ()) return "object";
if (node.is_string ()) return "string";
unreachable ();
}
bool
is_node_valid (const json::node &node,
const json::object &schema);
bool
is_type_valid (const json::node &node,
const json::node &type) {
if (type.is_array ()) {
return any_of (type.as_array ().begin (),
type.as_array ().end (),
bind (is_type_valid, ref (node), _1));
}
if (!type.is_string ())
throw json::schema_error ("schema type requires array, string, or object");
static const auto ANY_VALIDATOR = [] (const json::node &) { return true; };
static const auto INT_VALIDATOR = [] (const json::node &n) {
return n.is_number () && is_integer (n.as_number ());
};
static const map<string, function<bool(const json::node&)>> TYPE_VALIDATORS ({
{ "array", bind (&json::node::is_array, _1) },
{ "boolean", bind (&json::node::is_boolean, _1) },
{ "null", bind (&json::node::is_null, _1) },
{ "number", bind (&json::node::is_number, _1) },
{ "object", bind (&json::node::is_object, _1) },
{ "string", bind (&json::node::is_string, _1) },
{ "any", ANY_VALIDATOR },
{ "integer", INT_VALIDATOR },
});
auto pos = TYPE_VALIDATORS.find (type.as_string ().native ());
if (pos == TYPE_VALIDATORS.end ()) {
std::cerr << "warning: unknown type " << type.as_string ().native () << ". assuming valid.\n";
return true;
}
return pos->second(node);
}
bool
is_disallow_valid (const json::node &node,
const json::node &constraint)
{ return !is_type_valid (node, constraint); }
bool
is_enum_valid (const json::node &node,
const json::node &constraint) {
if (!constraint.is_array ())
throw json::schema_error ("enum validation requires an array");
const json::array &valids = constraint.as_array ();
return valids.end () != std::find (valids.begin (),
valids.end (),
node);
}
bool
is_enum_valid (const json::string &node,
const json::node &constraint) {
return is_enum_valid (static_cast<const json::node&> (node), constraint);
}
bool
is_always_valid (const json::node &,
const json::node &)
{ return true; }
/*static const map<string, validator_t> COMMON_VALIDATORS ({
{ "description", &is_always_valid },
{ "disallow", &is_disallow_valid },
{ "enum", &is_enum_valid },
{ "title", &is_always_valid },
{ "type", &is_type_valid },
});*/
bool
is_boolean_valid (const json::node &node,
const json::object &)
{ return node.is_boolean (); }
bool
is_null_valid (const json::node &node,
const json::object &)
{ return node.is_null (); }
//
// JSON number
//
bool
is_minimum_valid (const json::number &node,
const json::node &constraint) {
return constraint["minimum"].as_number () <= node;
}
bool
is_maximum_valid (const json::number &node,
const json::node &constraint) {
return constraint["maximum"].as_number () >= node;
}
bool
is_exclusive_minimum_valid (const json::number &node,
const json::node &constraint) {
return constraint["exclusiveMinimum"].as_number () < node;
}
bool
is_exclusive_maximum_valid (const json::number &node,
const json::node &constraint) {
return constraint["exclusiveMaximum"].as_number () > node;
}
bool
is_divisible_by_valid (const json::number &node,
const json::node &constraint) {
return exactly_equal (fmod (node.native (),
constraint["divisibleBy"].as_number ()),
0.0);
}
bool
is_number_valid (const json::number &node,
const json::object &schema) {
typedef bool (*number_validator_t)(const json::number&, const json::node&);
static const map<string, number_validator_t> VALIDATORS = {
{ "minimum", &is_minimum_valid },
{ "maximum", &is_maximum_valid },
{ "exclusiveMinimum", &is_exclusive_minimum_valid },
{ "exclusiveMaximum", &is_exclusive_maximum_valid },
{ "divisibleBy", &is_divisible_by_valid },
};
for (const auto &i: schema) {
const std::string &key = i.first;
const auto &validator = VALIDATORS.find (key);
if (validator == VALIDATORS.end ()) {
std::cerr << "Unknown validation constraint: " << key << "\n";
continue;
}
if (!validator->second (node, schema))
return false;
}
return true;
}
//
// JSON string
//
bool
is_min_length_valid (const json::string &node,
const json::node &constraint) {
if (!is_integer (constraint))
return false;
return node.size () >= constraint.as_number ();
}
bool
is_max_length_valid (const json::string &node,
const json::node &constraint) {
if (!is_integer (constraint))
return false;
return node.size () <= constraint.as_number ();
}
bool
is_pattern_valid (const json::string &node,
const json::node &constraint) {
if (!constraint.is_string ())
return false;
regex pattern (constraint.as_string ().native (),
regex_constants::ECMAScript);
return regex_match (node.native (), pattern);
}
bool
is_string_valid (const json::string &node,
const json::object &schema) {
typedef bool (*string_validator_t)(const json::string&, const json::node&);
static const map<std::string, string_validator_t> VALIDATORS = {
{ "minLength", &is_min_length_valid },
{ "maxLength", &is_max_length_valid },
{ "pattern", &is_pattern_valid },
{ "enum", &is_enum_valid },
};
for (const json::object::const_iterator::value_type &i: schema) {
const std::string &key = i.first;
const json::node &constraint = *i.second;
auto validator = VALIDATORS.find (key);
if (validator == VALIDATORS.end ()) {
std::cerr << "Unknown validation constraint: " << key << "\n";
continue;
}
if (!validator->second (node, constraint)) {
std::cerr << "Failed string constraint: " << key << "\n";
return false;
}
}
return true;
}
bool
is_string_valid (const json::node &node,
const json::object &schema) {
if (!node.is_string ())
return false;
return is_string_valid (node.as_string (), schema);
}
//
// JSON array
//
bool
is_max_items_valid (const json::array &node,
const json::node &constraint) {
if (!constraint.is_number () && is_integer (constraint.as_number ()))
throw json::schema_error ("max_items should be an integer");
return node.size () <= constraint.as_number ();
}
bool
is_min_items_valid (const json::array &node,
const json::node &constraint) {
if (!constraint.is_number () && is_integer (constraint.as_number ()))
throw json::schema_error ("min_items should be an integer");
return node.size () >= constraint.as_number ();
}
bool
is_unique_items_valid (const json::array &node,
const json::node &constraint) {
if (!constraint.is_boolean ())
throw json::schema_error ("uniqueItems must be a boolean");
if (node.size () < 2)
return true;
for (json::array::const_iterator i = node.begin (); i != node.end () - 1; ++i) {
if (find (i + 1, node.end (), *i) != node.end ())
return false;
}
return true;
}
bool
is_items_valid (const json::array &node,
const json::node &_schema) {
if (!_schema.is_object ())
throw json::schema_error ("array_items constraint must be an object");
const json::object &schema = _schema.as_object ();
for (const json::node &i: node)
if (!is_node_valid (i, schema))
return false;
return true;
not_implemented ();
return false;
}
bool
is_additional_items_valid (const json::array &,
const json::node &) {
not_implemented ();
return false;
}
bool
is_array_valid (const json::array &node,
const json::object &schema) {
CHECK_HARD (node.is_array ());
typedef bool (*array_validator_t)(const json::array&, const json::node&);
static const map<string, array_validator_t> VALIDATORS ({
{ "items", &is_items_valid },
{ "minItems", &is_min_items_valid },
{ "maxItems", &is_max_items_valid },
{ "uniqueItems", &is_unique_items_valid },
{ "additionalItems", &is_additional_items_valid },
});
for (const json::object::const_iterator::value_type &i: schema) {
const std::string &key = i.first;
const json::node &constraint = *i.second;
auto validator = VALIDATORS.find (key);
if (validator == VALIDATORS.end ()) {
std::cerr << "Ignoring unknown contraint key: " << key << "\n";
continue;
}
if (!validator->second (node, constraint)) {
std::cerr << "Failed validating array constraint: " << key << "\n";
return false;
}
}
return true;
}
//
// JSON object
//
bool
is_properties_valid (const json::object &node,
const json::object &schema) {
for (const json::object::const_iterator::value_type &element: node) {
const std::string &key = element.first;
const json::node &val = *element.second;
if (!schema.has (key)) {
std::cerr << "[warning] no constraint found for key: " << key << "\n";
continue;
}
if (!is_node_valid (val, schema[key].as_object ())) {
std::cerr << "failed validation on property: " << key << "\n";
return false;
}
}
return true;
}
bool
is_properties_valid (const json::object &node,
const json::node &constraint) {
CHECK (node.is_object ());
if (!constraint.is_object ())
throw json::schema_error ("properties needs an object");
return is_properties_valid (node, constraint.as_object ());
}
bool
is_object_valid (const json::object &node,
const json::object &schema) {
typedef bool (*object_validator_t)(const json::object&, const json::node&);
static const map<string, object_validator_t> VALIDATORS = {
{ "properties", &is_properties_valid },
//{ "patternProperties", &is_pattern_properties_valid },
//{ "additionalProperties", &is_additionaL_properties_valid },
};
for (const json::object::const_iterator::value_type &i: schema) {
const std::string &name = i.first;
const json::node &constraint = *i.second;
auto validator = VALIDATORS.find (name);
if (validator == VALIDATORS.end ()) {
std::cerr << "Unknown constraint name \"" << name << "\". Ignoring.\n";
continue;
}
if (!validator->second(node, constraint)) {
std::cerr << "Failed validation on: " << name << "\n";
return false;
}
}
return true;
}
bool
is_object_valid (const json::node &node,
const json::object &schema) {
if (!node.is_object ())
return false;
return is_object_valid (node.as_object (), schema);
}
//
// JSON node
//
bool
is_node_valid (const json::node &node,
const json::object &schema) {
if (schema.has ("$ref")) {
const std::string &uri = schema["$ref"].as_string ();
std::cerr << "loading referenced schema: " << uri << "\n";
if (uri[0] == '#') {
std::cerr << "[error] schema fragments are not supported\n";
return false;
}
auto referenced = json::parse (boost::filesystem::path (uri));
return is_node_valid (node, referenced->as_object ());
}
if (schema.has ("type") &&
!is_type_valid (node, schema["type"]))
{
std::cerr << "node type is \"" << type_to_string (node) << "\", expected " << schema["type"] << "\n";
return false;
}
#define IS_VALID(T) \
do { \
if (node.is_##T ()) { \
if (!is_##T##_valid (node.as_##T (), schema)) { \
std::cerr << "Failed validation as " #T "\n"; \
return false; \
} \
return true; \
} \
} while (0)
IS_VALID(array);
IS_VALID(boolean);
IS_VALID(null);
IS_VALID(number);
IS_VALID(object);
IS_VALID(string);
#undef IS_VALID
return false;
/*static const map<string, validator_t> VALIDATORS ({
{ "description", &is_always_valid },
{ "disallow", &is_disallow_valid },
{ "enum", &is_enum_valid },
{ "title", &is_always_valid },
{ "type", &is_type_valid },
});*/
//"required";
return false;
}
bool
is_root_valid (const json::node &node,
const json::object &schema) {
if (!node.is_array () && !node.is_object ())
return false;
return is_node_valid (node, schema);
}
//
// Driver
//
int
main (int argc, char **argv) {
// Basic argument checking
if (argc != NUM_ARGS) {
print_usage (argc, argv);
return EXIT_FAILURE;
}
// Load the schema and input
unique_ptr<json::node> schema, input;
try {
schema = json::parse (boost::filesystem::path (argv[ARG_SCHEMA]));
input = json::parse (boost::filesystem::path (argv[ARG_INPUT]));
} catch (const json::parse_error &err) {
std::cerr << "malformed json for schema or input. " << err.what () << "\n";
return EXIT_FAILURE;
}
// Check schema is valid
if (!schema->is_object ()) {
std::cerr << "Schema should be an object\n";
return EXIT_FAILURE;
}
const json::object &schema_object = schema->as_object ();
// Check input is valid
if (!is_node_valid (*input, schema_object)) {
std::cerr << "input does not satisfy the schema\n";
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}