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#include <iostream>
#include "simdjson.h"
using namespace std;
using namespace simdjson;
using error_code=simdjson::error_code;
void basics_1() {
const char *filename = "x.txt";
dom::parser parser;
dom::element doc = parser.load(filename); // load and parse a file
cout << doc;
}
void basics_2() {
dom::parser parser;
dom::element doc = parser.parse("[1,2,3]"_padded); // parse a string
cout << doc;
}
void wild() {
simdjson::padded_string json_string = R"(
{
"firstName": "John",
"lastName": "doe",
"age": 26,
"address": {
"streetAddress": "naist street",
"city": "Nara",
"postalCode": "630-0192"
},
"phoneNumbers": [
{
"type": "iPhone",
"numbers": ["0123-4567-8888", "0123-4567-8788"]
},
{
"type": "home",
"numbers": ["0123-4567-8910"]
}
]
})"_padded;
dom::parser parser;
dom::element parsed_json = parser.parse(json_string);
std::vector<dom::element> values;
// Fetch all fields in the address object
auto error = parsed_json.at_path_with_wildcard("$.address.*").get(values);
if(error) {
// do something
}
for (auto &value : values) {
std::string_view field;
error = value.get(field);
if(error) {
// do something
}
std::cout << field << std::endl;
}
// Fetch all phone numbers
error = parsed_json.at_path_with_wildcard("$.phoneNumbers[*].numbers[*]").get(values);
if(error) {
// do something
}
for (auto &value : values) {
std::string_view number;
error = value.get(number);
if(error) {
// do something
}
std::cout << number << std::endl;
}
}
void basics_dom_1() {
auto cars_json = R"( [
{ "make": "Toyota", "model": "Camry", "year": 2018, "tire_pressure": [ 40.1, 39.9, 37.7, 40.4 ] },
{ "make": "Kia", "model": "Soul", "year": 2012, "tire_pressure": [ 30.1, 31.0, 28.6, 28.7 ] },
{ "make": "Toyota", "model": "Tercel", "year": 1999, "tire_pressure": [ 29.8, 30.0, 30.2, 30.5 ] }
] )"_padded;
dom::parser parser;
// Parse and iterate through each car
for (dom::object car : parser.parse(cars_json)) {
// Accessing a field by name
cout << "Make/Model: " << car["make"] << "/" << car["model"] << endl;
// Casting a JSON element to an integer
uint64_t year = car["year"];
cout << "- This car is " << 2020 - year << "years old." << endl;
// Iterating through an array of floats
double total_tire_pressure = 0;
for (double tire_pressure : car["tire_pressure"]) {
total_tire_pressure += tire_pressure;
}
cout << "- Average tire pressure: " << (total_tire_pressure / 4) << endl;
// Writing out all the information about the car
for (auto field : car) {
cout << "- " << field.key << ": " << field.value << endl;
}
}
}
void parse_many_truncated() {
auto json = R"([1,2,3] {"1":1,"2":3,"4":4} {"key":"intentionally unclosed string )"_padded;
simdjson::dom::parser parser;
simdjson::dom::document_stream stream;
auto error = parser.parse_many(json,json.size()).get(stream);
if(error) { std::cerr << error << std::endl; return; }
for(auto doc : stream) {
std::cout << doc << std::endl;
}
std::cout << stream.truncated_bytes() << " bytes "<< std::endl; // returns 39 bytes
}
void basics_dom_2() {
auto cars_json = R"( [
{ "make": "Toyota", "model": "Camry", "year": 2018, "tire_pressure": [ 40.1, 39.9, 37.7, 40.4 ] },
{ "make": "Kia", "model": "Soul", "year": 2012, "tire_pressure": [ 30.1, 31.0, 28.6, 28.7 ] },
{ "make": "Toyota", "model": "Tercel", "year": 1999, "tire_pressure": [ 29.8, 30.0, 30.2, 30.5 ] }
] )"_padded;
dom::parser parser;
dom::element cars = parser.parse(cars_json);
cout << cars.at_pointer("/0/tire_pressure/1") << endl; // Prints 39.9
for (dom::element car_element : cars) {
dom::object car;
simdjson::error_code error;
if ((error = car_element.get(car))) { std::cerr << error << std::endl; return; }
double x = car.at_pointer("/tire_pressure/1");
cout << x << endl; // Prints 39.9, 31 and 30
}
}
void basics_dom_3() {
auto abstract_json = R"( [
{ "12345" : {"a":12.34, "b":56.78, "c": 9998877} },
{ "12545" : {"a":11.44, "b":12.78, "c": 11111111} }
] )"_padded;
dom::parser parser;
// Parse and iterate through an array of objects
for (dom::object obj : parser.parse(abstract_json)) {
for(const auto key_value : obj) {
cout << "key: " << key_value.key << " : ";
dom::object innerobj = key_value.value;
cout << "a: " << double(innerobj["a"]) << ", ";
cout << "b: " << double(innerobj["b"]) << ", ";
cout << "c: " << int64_t(innerobj["c"]) << endl;
}
}
}
void basics_dom_4() {
auto abstract_json = R"(
{ "str" : { "123" : {"abc" : 3.14 } } } )"_padded;
dom::parser parser;
double v = parser.parse(abstract_json)["str"]["123"]["abc"];
cout << "number: " << v << endl;
}
namespace ondemand_treewalk {
// We use a template function because we need to
// support both ondemand::value and ondemand::document
// as a parameter type. Note that we move the values.
template <class T>
void recursive_print_json(T&& element) {
bool add_comma;
switch (element.type()) {
case ondemand::json_type::array:
cout << "[";
add_comma = false;
for (auto child : element.get_array()) {
if (add_comma) {
cout << ",";
}
// We need the call to value() to get
// an ondemand::value type.
recursive_print_json(child.value());
add_comma = true;
}
cout << "]";
break;
case ondemand::json_type::object:
cout << "{";
add_comma = false;
for (auto field : element.get_object()) {
if (add_comma) {
cout << ",";
}
// key() returns the unescaped key, if we
// want the escaped key, we should do
// field.unescaped_key().
cout << "\"" << field.key() << "\": ";
recursive_print_json(field.value());
add_comma = true;
}
cout << "}";
break;
case ondemand::json_type::number:
// assume it fits in a double
cout << element.get_double();
break;
case ondemand::json_type::string:
// get_string() would return escaped string, but
// we are happy with unescaped string.
cout << "\"" << element.get_raw_json_string() << "\"";
break;
case ondemand::json_type::boolean:
cout << element.get_bool();
break;
case ondemand::json_type::null:
// We check that the value is indeed null
// otherwise: an error is thrown.
if(element.is_null()) {
cout << "null";
}
break;
case ondemand::json_type::unknown:
cout << "unknown"; // indicates an error
break;
}
}
void basics_treewalk() {
ondemand::parser parser;
auto json = padded_string::load("twitter.json");
recursive_print_json(parser.iterate(json));
}
}
namespace treewalk_1 {
void print_json(dom::element element) {
switch (element.type()) {
case dom::element_type::ARRAY:
cout << "[";
for (dom::element child : dom::array(element)) {
print_json(child);
cout << ",";
}
cout << "]";
break;
case dom::element_type::OBJECT:
cout << "{";
for (dom::key_value_pair field : dom::object(element)) {
cout << "\"" << field.key << "\": ";
print_json(field.value);
}
cout << "}";
break;
case dom::element_type::INT64:
cout << int64_t(element) << endl;
break;
case dom::element_type::UINT64:
cout << uint64_t(element) << endl;
break;
case dom::element_type::DOUBLE:
cout << double(element) << endl;
break;
case dom::element_type::STRING:
cout << std::string_view(element) << endl;
break;
case dom::element_type::BOOL:
cout << bool(element) << endl;
break;
case dom::element_type::NULL_VALUE:
cout << "null" << endl;
break;
}
}
void basics_treewalk_1() {
dom::parser parser;
print_json(parser.load("twitter.json"));
}
}
#ifdef SIMDJSON_CPLUSPLUS17
void basics_cpp17_1() {
padded_string json = R"( { "foo": 1, "bar": 2 } )"_padded;
dom::parser parser;
dom::object object;
auto error = parser.parse(json).get(object);
if (error) { cerr << error << endl; return; }
for (auto [key, value] : object) {
cout << key << " = " << value << endl;
}
}
#endif
void basics_cpp17_2() {
// C++ 11 version for comparison
padded_string json = R"( { "foo": 1, "bar": 2 } )"_padded;
dom::parser parser;
dom::object object;
auto error = parser.parse(json).get(object);
if (error) { cerr << error << endl; return; }
for (dom::key_value_pair field : object) {
cout << field.key << " = " << field.value << endl;
}
}
void basics_ndjson() {
dom::parser parser;
for (dom::element doc : parser.load_many("x.txt")) {
cout << doc["foo"] << endl;
}
// Prints 1 2 3
}
void basics_ndjson_parse_many() {
dom::parser parser;
auto json = R"({ "foo": 1 }
{ "foo": 2 }
{ "foo": 3 })"_padded;
dom::document_stream docs = parser.parse_many(json);
for (dom::element doc : docs) {
cout << doc["foo"] << endl;
}
}
void implementation_selection_1() {
cout << "simdjson v" << SIMDJSON_VERSION << endl;
cout << "Detected the best implementation for your machine: " << simdjson::get_active_implementation()->name();
cout << "(" << simdjson::get_active_implementation()->description() << ")" << endl;
}
void unescaped_key() {
auto json = R"({"k\u0065y": 1})"_padded;
ondemand::parser parser;
auto doc = parser.iterate(json);
ondemand::object object = doc.get_object();
for(auto field : object) {
// parses and writes out the key, after unescaping it,
// to a string buffer. This should be expected to be much
// more costly than accessing the raw string ("key()").
std::string_view keyv = field.unescaped_key();
if(keyv == "key") {
std::cout << uint64_t(field.value());
}
// You can access the raw value like so:
// ondemand::raw_json_string keyv = field.key();
// if(keyv == R"(k\u0065y)") {
}
}
void implementation_selection_2() {
for (auto implementation : simdjson::get_available_implementations()) {
cout << implementation->name() << ": " << implementation->description() << endl;
}
}
void implementation_selection_2_safe() {
for (auto implementation : simdjson::get_available_implementations()) {
if(implementation->supported_by_runtime_system()) {
cout << implementation->name() << ": " << implementation->description() << endl;
}
}
}
void implementation_selection_3() {
cout << simdjson::get_available_implementations()["fallback"]->description() << endl;
}
void implementation_selection_safe() {
auto my_implementation = simdjson::get_available_implementations()["haswell"];
if(! my_implementation) { exit(1); }
if(! my_implementation->supported_by_runtime_system()) { exit(1); }
simdjson::get_active_implementation() = my_implementation;
}
void implementation_selection_4() {
// Use the fallback implementation, even though my machine is fast enough for anything
simdjson::get_active_implementation() = simdjson::get_available_implementations()["fallback"];
}
void ondemand_performance_1() {
ondemand::parser parser;
// This initializes buffers big enough to handle this JSON.
auto json = "[ true, false ]"_padded;
auto doc = parser.iterate(json);
for(bool i : doc.get_array()) {
cout << i << endl;
}
// This reuses the existing buffers
auto number_json = "[1, 2, 3]"_padded;
doc = parser.iterate(number_json);
for(int64_t i : doc.get_array()) {
cout << i << endl;
}
}
void performance_1() {
dom::parser parser;
// This initializes buffers and a document big enough to handle this JSON.
dom::element doc = parser.parse("[ true, false ]"_padded);
cout << doc << endl;
// This reuses the existing buffers, and reuses and *overwrites* the old document
doc = parser.parse("[1, 2, 3]"_padded);
cout << doc << endl;
// This also reuses the existing buffers, and reuses and *overwrites* the old document
dom::element doc2 = parser.parse("true"_padded);
// Even if you keep the old reference around, doc and doc2 refer to the same document.
cout << doc << endl;
cout << doc2 << endl;
}
#ifdef SIMDJSON_CPLUSPLUS17
SIMDJSON_PUSH_DISABLE_ALL_WARNINGS
// The web_request part of this is aspirational, so we compile as much as we can here
void performance_2() {
dom::parser parser(1000*1000); // Never grow past documents > 1MB
/* for (web_request request : listen()) */ {
dom::element doc;
auto body = "1"_padded; /*request.body*/
auto error = parser.parse(body/*request.body*/).get(doc);
// If the document was above our limit, emit 413 = payload too large
if (error == CAPACITY) { /* request.respond(413); continue; */ }
// ...
}
}
// The web_request part of this is aspirational, so we compile as much as we can here
void performance_3() {
dom::parser parser(0); // This parser will refuse to automatically grow capacity
auto error = parser.allocate(1000*1000); // This allocates enough capacity to handle documents <= 1MB
if (error) { cerr << error << endl; exit(1); }
/* for (web_request request : listen()) */ {
dom::element doc;
auto body = "1"_padded;/*request.body*/
auto error = parser.parse(body).get(doc);
// If the document was above our limit, emit 413 = payload too large
if (error == CAPACITY) { /* request.respond(413); continue; */ }
// ...
}
}
SIMDJSON_POP_DISABLE_WARNINGS
#endif
void minify() {
const char * some_string = "[ 1, 2, 3, 4] ";
size_t length = std::strlen(some_string);
std::unique_ptr<char[]> buffer{new char[length]};
size_t new_length{};
auto error = simdjson::minify(some_string, length, buffer.get(), new_length);
if(error != simdjson::SUCCESS) {
std::cerr << "error " << error << std::endl;
abort();
} else {
const char * expected_string = "[1,2,3,4]";
size_t expected_length = std::strlen(expected_string);
if(expected_length != new_length) {
std::cerr << "mismatched length (error) " << std::endl;
abort();
}
for(size_t i = 0; i < new_length; i++) {
if(expected_string[i] != buffer.get()[i]) {
std::cerr << "mismatched content (error) " << std::endl;
abort();
}
}
}
}
bool is_correct() {
const char * some_string = "[ 1, 2, 3, 4] ";
size_t length = std::strlen(some_string);
bool is_ok = simdjson::validate_utf8(some_string, length);
return is_ok;
}
bool is_correct_string_view() {
const char * some_string = "[ 1, 2, 3, 4] ";
size_t length = std::strlen(some_string);
std::string_view v(some_string, length);
bool is_ok = simdjson::validate_utf8(v);
return is_ok;
}
bool is_correct_string() {
const std::string some_string = "[ 1, 2, 3, 4] ";
bool is_ok = simdjson::validate_utf8(some_string);
return is_ok;
}
void parse_documentation() {
const char *json = R"({"key":"value"})";
const size_t json_len = std::strlen(json);
simdjson::dom::parser parser;
simdjson::dom::element element = parser.parse(json, json_len);
// Next line is to avoid unused warning.
(void)element;
}
void parse_documentation_lowlevel() {
// Such low-level code is not generally recommended. Please
// see parse_documentation() instead.
// Motivation: https://github.com/simdjson/simdjson/issues/1175
const char *json = R"({"key":"value"})";
const size_t json_len = std::strlen(json);
std::unique_ptr<char[]> padded_json_copy{new char[json_len + SIMDJSON_PADDING]};
std::memcpy(padded_json_copy.get(), json, json_len);
std::memset(padded_json_copy.get() + json_len, '\0', SIMDJSON_PADDING);
simdjson::dom::parser parser;
simdjson::dom::element element = parser.parse(padded_json_copy.get(), json_len, false);
// Next line is to avoid unused warning.
(void)element;
}
void simplepad() {
std::string json = "[1]";
dom::parser parser;
dom::element doc;
auto error = parser.parse(simdjson::pad(json)).get(doc);
if(error) { exit(-1); }
}
void jsondollar() {
dom::parser parser;
auto json = R"( { "c" :{ "foo": { "a": [ 10, 20, 30 ] }}, "d": { "foo2": { "a": [ 10, 20, 30 ] }} , "e": 120 })"_padded;
dom::element doc;
auto error = parser.parse(json).get(doc);
if(error) { exit(-1); }
dom::object obj;
error = doc.get_object().get(obj);
if(error) { exit(-1); }
int64_t x = 0; // initialization to silence unwarranted compiler warning
error = obj.at_path("$[3].foo.a[1]").get(x);
if(error) { exit(-1); }
if(x != 20) { exit(-1); }
x = obj.at_path("$.d.foo2.a.2");
if(x != 30) { exit(-1); }
if(error) { exit(-1); }
}
void jsonpath() {
auto cars_json = R"( [
{ "make": "Toyota", "model": "Camry", "year": 2018, "tire_pressure": [ 40.1, 39.9, 37.7, 40.4 ] },
{ "make": "Kia", "model": "Soul", "year": 2012, "tire_pressure": [ 30.1, 31.0, 28.6, 28.7 ] },
{ "make": "Toyota", "model": "Tercel", "year": 1999, "tire_pressure": [ 29.8, 30.0, 30.2, 30.5 ] }
] )"_padded;
dom::parser parser;
dom::element doc;
auto error = parser.parse(cars_json).get(doc);
if(error) { exit(-1); }
double p = 0.0; // initialization to silence unwarranted compiler warning
error = doc.at_path("[0].tire_pressure[1]").get(p);
if(error) { exit(-1); }
if(p != 39.9) { exit(-1); }
}
int main() {
simplepad();
jsonpath();
jsondollar();
basics_dom_1();
basics_dom_2();
basics_dom_3();
basics_dom_4();
minify();
return 0;
}
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