tdlight/tdutils/td/utils/JsonBuilder.h
levlam 7f4593e21b Simplify json_array usage.
GitOrigin-RevId: 991f180938424074b41a858b125268d5a10fc8ac
2020-01-16 04:32:02 +03:00

861 lines
19 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#include "td/utils/common.h"
#include "td/utils/logging.h"
#include "td/utils/Parser.h"
#include "td/utils/Slice.h"
#include "td/utils/StackAllocator.h"
#include "td/utils/Status.h"
#include "td/utils/StringBuilder.h"
#include <new>
#include <type_traits>
#include <utility>
namespace td {
class JsonTrue {
public:
friend StringBuilder &operator<<(StringBuilder &sb, const JsonTrue &val) {
return sb << "true";
}
};
class JsonFalse {
public:
friend StringBuilder &operator<<(StringBuilder &sb, const JsonFalse &val) {
return sb << "false";
}
};
class JsonNull {
public:
friend StringBuilder &operator<<(StringBuilder &sb, JsonNull val) {
return sb << "null";
}
};
class JsonBool {
public:
explicit JsonBool(bool value) : value_(value) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonBool &val) {
if (val.value_) {
return sb << JsonTrue();
} else {
return sb << JsonFalse();
}
}
private:
bool value_;
};
class JsonInt {
public:
explicit JsonInt(int32 value) : value_(value) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonInt &val) {
return sb << val.value_;
}
private:
int32 value_;
};
class JsonLong {
public:
explicit JsonLong(int64 value) : value_(value) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonLong &val) {
return sb << val.value_;
}
private:
int64 value_;
};
class JsonFloat {
public:
explicit JsonFloat(double value) : value_(value) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonFloat &val) {
return sb << val.value_;
}
private:
double value_;
};
class JsonOneChar {
public:
explicit JsonOneChar(unsigned int c) : c_(c) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonOneChar &val) {
auto c = val.c_;
return sb << '\\' << 'u' << "0123456789abcdef"[c >> 12] << "0123456789abcdef"[(c >> 8) & 15]
<< "0123456789abcdef"[(c >> 4) & 15] << "0123456789abcdef"[c & 15];
}
private:
unsigned int c_;
};
class JsonChar {
public:
explicit JsonChar(unsigned int c) : c_(c) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonChar &val) {
auto c = val.c_;
if (c < 0x10000) {
if (0xD7FF < c && c < 0xE000) {
// UTF-8 correctness has already been checked
UNREACHABLE();
}
return sb << JsonOneChar(c);
} else if (c <= 0x10ffff) {
return sb << JsonOneChar(0xD7C0 + (c >> 10)) << JsonOneChar(0xDC00 + (c & 0x3FF));
} else {
// UTF-8 correctness has already been checked
UNREACHABLE();
}
}
private:
unsigned int c_;
};
class JsonRaw {
public:
explicit JsonRaw(Slice value) : value_(value) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonRaw &val) {
return sb << val.value_;
}
private:
Slice value_;
};
class JsonRawString {
public:
explicit JsonRawString(Slice value) : value_(value) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonRawString &val);
private:
Slice value_;
};
class JsonString {
public:
explicit JsonString(Slice str) : str_(str) {
}
friend StringBuilder &operator<<(StringBuilder &sb, const JsonString &val);
private:
Slice str_;
};
class JsonScope;
class JsonValueScope;
class JsonArrayScope;
class JsonObjectScope;
class JsonBuilder {
public:
explicit JsonBuilder(StringBuilder &&sb, int32 offset = -1) : sb_(std::move(sb)), offset_(offset) {
}
StringBuilder &string_builder() {
return sb_;
}
friend class JsonScope;
JsonValueScope enter_value() TD_WARN_UNUSED_RESULT;
JsonArrayScope enter_array() TD_WARN_UNUSED_RESULT;
JsonObjectScope enter_object() TD_WARN_UNUSED_RESULT;
int32 offset() const {
return offset_;
}
bool is_pretty() const {
return offset_ >= 0;
}
void print_offset() {
if (offset_ >= 0) {
sb_ << '\n';
for (int x = 0; x < offset_; x++) {
sb_ << " ";
}
}
}
void dec_offset() {
if (offset_ >= 0) {
CHECK(offset_ > 0);
offset_--;
}
}
void inc_offset() {
if (offset_ >= 0) {
offset_++;
}
}
private:
StringBuilder sb_;
JsonScope *scope_ = nullptr;
int32 offset_;
};
class Jsonable {};
class JsonScope {
public:
explicit JsonScope(JsonBuilder *jb) : sb_(&jb->sb_), jb_(jb), save_scope_(jb->scope_) {
jb_->scope_ = this;
CHECK(is_active());
}
JsonScope(const JsonScope &other) = delete;
JsonScope(JsonScope &&other) : sb_(other.sb_), jb_(other.jb_), save_scope_(other.save_scope_) {
other.jb_ = nullptr;
}
JsonScope &operator=(const JsonScope &) = delete;
JsonScope &operator=(JsonScope &&) = delete;
~JsonScope() {
if (jb_) {
leave();
}
}
void leave() {
CHECK(is_active());
jb_->scope_ = save_scope_;
}
protected:
StringBuilder *sb_;
// For CHECK
JsonBuilder *jb_;
JsonScope *save_scope_;
bool is_active() const {
return jb_ && jb_->scope_ == this;
}
JsonScope &operator<<(JsonTrue x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(JsonFalse x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(JsonNull x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonBool &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonInt &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonLong &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonFloat &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonString &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonRawString &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(const JsonRaw &x) {
*sb_ << x;
return *this;
}
JsonScope &operator<<(bool x) = delete;
JsonScope &operator<<(int32 x) {
return *this << JsonInt(x);
}
JsonScope &operator<<(int64 x) {
return *this << JsonLong(x);
}
JsonScope &operator<<(double x) {
return *this << JsonFloat(x);
}
template <size_t N>
JsonScope &operator<<(const char (&x)[N]) {
return *this << JsonString(Slice(x));
}
JsonScope &operator<<(const char *x) {
return *this << JsonString(Slice(x));
}
JsonScope &operator<<(Slice x) {
return *this << JsonString(x);
}
};
class JsonValueScope : public JsonScope {
public:
using JsonScope::JsonScope;
template <class T>
std::enable_if_t<std::is_base_of<Jsonable, typename std::decay<T>::type>::value, JsonValueScope &> operator<<(
const T &x) {
x.store(this);
return *this;
}
template <class T>
std::enable_if_t<!std::is_base_of<Jsonable, typename std::decay<T>::type>::value, JsonValueScope &> operator<<(
const T &x) {
CHECK(!was_);
was_ = true;
JsonScope::operator<<(x);
return *this;
}
JsonArrayScope enter_array() TD_WARN_UNUSED_RESULT;
JsonObjectScope enter_object() TD_WARN_UNUSED_RESULT;
private:
bool was_ = false;
};
class JsonArrayScope : public JsonScope {
public:
explicit JsonArrayScope(JsonBuilder *jb) : JsonScope(jb) {
jb->inc_offset();
*sb_ << "[";
}
JsonArrayScope(JsonArrayScope &&other) = default;
~JsonArrayScope() {
if (jb_) {
leave();
}
}
void leave() {
jb_->dec_offset();
jb_->print_offset();
*sb_ << "]";
}
template <class T>
JsonArrayScope &operator<<(const T &x) {
return (*this)(x);
}
template <class T>
JsonArrayScope &operator()(const T &x) {
enter_value() << x;
return *this;
}
JsonValueScope enter_value() {
CHECK(is_active());
if (is_first_) {
*sb_ << ",";
} else {
is_first_ = true;
}
jb_->print_offset();
return jb_->enter_value();
}
private:
bool is_first_ = false;
};
class JsonObjectScope : public JsonScope {
public:
explicit JsonObjectScope(JsonBuilder *jb) : JsonScope(jb) {
jb->inc_offset();
*sb_ << "{";
}
JsonObjectScope(JsonObjectScope &&other) = default;
~JsonObjectScope() {
if (jb_) {
leave();
}
}
void leave() {
jb_->dec_offset();
jb_->print_offset();
*sb_ << "}";
}
template <class T>
JsonObjectScope &operator()(Slice key, T &&value) {
CHECK(is_active());
if (is_first_) {
*sb_ << ",";
} else {
is_first_ = true;
}
jb_->print_offset();
jb_->enter_value() << key;
if (jb_->is_pretty()) {
*sb_ << " : ";
} else {
*sb_ << ":";
}
jb_->enter_value() << value;
return *this;
}
JsonObjectScope &operator<<(const JsonRaw &key_value) {
CHECK(is_active());
is_first_ = true;
jb_->enter_value() << key_value;
return *this;
}
private:
bool is_first_ = false;
};
inline JsonArrayScope JsonValueScope::enter_array() {
CHECK(!was_);
was_ = true;
return JsonArrayScope(jb_);
}
inline JsonObjectScope JsonValueScope::enter_object() {
CHECK(!was_);
was_ = true;
return JsonObjectScope(jb_);
}
inline JsonValueScope JsonBuilder::enter_value() {
return JsonValueScope(this);
}
inline JsonObjectScope JsonBuilder::enter_object() {
return JsonObjectScope(this);
}
inline JsonArrayScope JsonBuilder::enter_array() {
return JsonArrayScope(this);
}
class JsonValue;
using JsonObject = vector<std::pair<MutableSlice, JsonValue>>;
using JsonArray = vector<JsonValue>;
class JsonValue : public Jsonable {
public:
enum class Type { Null, Number, Boolean, String, Array, Object };
static Slice get_type_name(Type type);
JsonValue() {
}
~JsonValue() {
destroy();
}
JsonValue(JsonValue &&other) : JsonValue() {
init(std::move(other));
}
JsonValue &operator=(JsonValue &&other) {
if (&other == this) {
return *this;
}
destroy();
init(std::move(other));
return *this;
}
JsonValue(const JsonValue &other) = delete;
JsonValue &operator=(const JsonValue &other) = delete;
Type type() const {
return type_;
}
MutableSlice &get_string() {
CHECK(type_ == Type::String);
return string_;
}
const MutableSlice &get_string() const {
CHECK(type_ == Type::String);
return string_;
}
bool &get_boolean() {
CHECK(type_ == Type::Boolean);
return boolean_;
}
const bool &get_boolean() const {
CHECK(type_ == Type::Boolean);
return boolean_;
}
MutableSlice &get_number() {
CHECK(type_ == Type::Number);
return number_;
}
const MutableSlice &get_number() const {
CHECK(type_ == Type::Number);
return number_;
}
JsonArray &get_array() {
CHECK(type_ == Type::Array);
return array_;
}
const JsonArray &get_array() const {
CHECK(type_ == Type::Array);
return array_;
}
JsonObject &get_object() {
CHECK(type_ == Type::Object);
return object_;
}
const JsonObject &get_object() const {
CHECK(type_ == Type::Object);
return object_;
}
static JsonValue create_boolean(bool val) {
JsonValue res;
res.init_boolean(val);
return res;
}
static JsonValue create_number(MutableSlice number) {
JsonValue res;
res.init_number(number);
return res;
}
static JsonValue create_string(MutableSlice str) {
JsonValue res;
res.init_string(str);
return res;
}
static JsonValue create_array(JsonArray v) {
JsonValue res;
res.init_array(std::move(v));
return res;
}
static JsonValue make_object(JsonObject c) {
JsonValue res;
res.init_object(std::move(c));
return res;
}
void store(JsonValueScope *scope) const {
switch (type_) {
case Type::Null:
*scope << JsonRaw("null");
break;
case Type::Boolean:
if (get_boolean()) {
*scope << JsonRaw("true");
} else {
*scope << JsonRaw("false");
}
break;
case Type::Number:
*scope << JsonRaw(get_number());
break;
case Type::String:
*scope << JsonString(get_string());
break;
case Type::Array: {
auto arr = scope->enter_array();
for (auto &val : get_array()) {
arr << val;
}
break;
}
case Type::Object: {
auto object = scope->enter_object();
for (auto &key_value : get_object()) {
object(key_value.first, key_value.second);
}
break;
}
}
};
private:
Type type_{Type::Null};
union {
MutableSlice number_;
bool boolean_;
MutableSlice string_;
JsonArray array_;
JsonObject object_;
};
void init_null() {
type_ = Type::Null;
}
void init_number(MutableSlice number) {
type_ = Type::Number;
new (&number_) MutableSlice(number);
}
void init_boolean(bool boolean) {
type_ = Type::Boolean;
boolean_ = boolean;
}
void init_string(MutableSlice slice) {
type_ = Type::String;
new (&string_) MutableSlice(slice);
}
void init_array(JsonArray array) {
type_ = Type::Array;
new (&array_) JsonArray(std::move(array));
}
void init_object(JsonObject object) {
type_ = Type::Object;
new (&object_) JsonObject(std::move(object));
}
void init(JsonValue &&other) {
switch (other.type_) {
case Type::Null:
break;
case Type::Number:
init_number(other.number_);
break;
case Type::Boolean:
init_boolean(other.boolean_);
break;
case Type::String:
init_string(other.string_);
break;
case Type::Array:
init_array(std::move(other.array_));
break;
case Type::Object:
init_object(std::move(other.object_));
break;
}
other.destroy();
}
void destroy() {
switch (type_) {
case Type::Null:
case Type::Boolean:
break;
case Type::Number:
number_.~MutableSlice();
break;
case Type::String:
string_.~MutableSlice();
break;
case Type::Array:
array_.~vector<JsonValue>();
break;
case Type::Object:
object_.~vector<std::pair<MutableSlice, JsonValue>>();
break;
}
type_ = Type::Null;
}
};
inline StringBuilder &operator<<(StringBuilder &sb, JsonValue::Type type) {
switch (type) {
case JsonValue::Type::Null:
return sb << "Null";
case JsonValue::Type::Number:
return sb << "Number";
case JsonValue::Type::Boolean:
return sb << "Boolean";
case JsonValue::Type::String:
return sb << "String";
case JsonValue::Type::Array:
return sb << "Array";
case JsonValue::Type::Object:
return sb << "Object";
default:
UNREACHABLE();
return sb;
}
}
class VirtuallyJsonable : public Jsonable {
public:
virtual void store(JsonValueScope *scope) const = 0;
VirtuallyJsonable() = default;
VirtuallyJsonable(const VirtuallyJsonable &) = delete;
VirtuallyJsonable &operator=(const VirtuallyJsonable &) = delete;
VirtuallyJsonable(VirtuallyJsonable &&) = default;
VirtuallyJsonable &operator=(VirtuallyJsonable &&) = default;
virtual ~VirtuallyJsonable() = default;
};
class VirtuallyJsonableInt : public VirtuallyJsonable {
public:
explicit VirtuallyJsonableInt(int32 value) : value_(value) {
}
void store(JsonValueScope *scope) const override {
*scope << JsonInt(value_);
}
private:
int32 value_;
};
class VirtuallyJsonableLong : public VirtuallyJsonable {
public:
explicit VirtuallyJsonableLong(int64 value) : value_(value) {
}
void store(JsonValueScope *scope) const override {
*scope << JsonLong(value_);
}
private:
int64 value_;
};
class VirtuallyJsonableString : public VirtuallyJsonable {
public:
explicit VirtuallyJsonableString(Slice value) : value_(value) {
}
void store(JsonValueScope *scope) const override {
*scope << JsonString(value_);
}
private:
Slice value_;
};
Result<MutableSlice> json_string_decode(Parser &parser) TD_WARN_UNUSED_RESULT;
Status json_string_skip(Parser &parser) TD_WARN_UNUSED_RESULT;
Result<JsonValue> do_json_decode(Parser &parser, int32 max_depth) TD_WARN_UNUSED_RESULT;
Status do_json_skip(Parser &parser, int32 max_depth) TD_WARN_UNUSED_RESULT;
inline Result<JsonValue> json_decode(MutableSlice json) {
Parser parser(json);
const int32 DEFAULT_MAX_DEPTH = 100;
auto result = do_json_decode(parser, DEFAULT_MAX_DEPTH);
if (result.is_ok()) {
parser.skip_whitespaces();
if (!parser.empty()) {
return Status::Error("Expected string end");
}
}
return result;
}
template <class StrT, class ValT>
StrT json_encode(const ValT &val, bool pretty = false) {
auto buf_len = 1 << 18;
auto buf = StackAllocator::alloc(buf_len);
JsonBuilder jb(StringBuilder(buf.as_slice(), true), pretty ? 0 : -1);
jb.enter_value() << val;
if (pretty) {
jb.string_builder() << "\n";
}
LOG_IF(ERROR, jb.string_builder().is_error()) << "JSON buffer overflow";
auto slice = jb.string_builder().as_cslice();
return StrT(slice.begin(), slice.size());
}
template <class T>
class ToJsonImpl : public Jsonable {
public:
explicit ToJsonImpl(const T &value) : value_(value) {
}
void store(JsonValueScope *scope) const {
to_json(*scope, value_);
}
private:
const T &value_;
};
template <class T>
auto ToJson(const T &value) {
return ToJsonImpl<T>(value);
}
template <class T>
void to_json(JsonValueScope &jv, const T &value) {
jv << value;
}
template <class F>
class JsonObjectImpl : Jsonable {
public:
explicit JsonObjectImpl(F &&f) : f_(std::forward<F>(f)) {
}
void store(JsonValueScope *scope) const {
auto object = scope->enter_object();
f_(object);
}
private:
F f_;
};
template <class F>
auto json_object(F &&f) {
return JsonObjectImpl<F>(std::forward<F>(f));
}
template <class F>
class JsonArrayImpl : Jsonable {
public:
explicit JsonArrayImpl(F &&f) : f_(std::forward<F>(f)) {
}
void store(JsonValueScope *scope) const {
auto array = scope->enter_array();
f_(array);
}
private:
F f_;
};
template <class F>
auto json_array(F &&f) {
return JsonArrayImpl<F>(std::forward<F>(f));
}
template <class A, class F>
auto json_array(const A &a, F &&f) {
return json_array([&a, &f](auto &arr) {
for (auto &x : a) {
arr(f(x));
}
});
}
bool has_json_object_field(const JsonObject &object, Slice name);
JsonValue get_json_object_field_force(JsonObject &object, Slice name) TD_WARN_UNUSED_RESULT;
Result<JsonValue> get_json_object_field(JsonObject &object, Slice name, JsonValue::Type type,
bool is_optional = true) TD_WARN_UNUSED_RESULT;
Result<bool> get_json_object_bool_field(JsonObject &object, Slice name, bool is_optional = true,
bool default_value = false) TD_WARN_UNUSED_RESULT;
Result<int32> get_json_object_int_field(JsonObject &object, Slice name, bool is_optional = true,
int32 default_value = 0) TD_WARN_UNUSED_RESULT;
Result<int64> get_json_object_long_field(JsonObject &object, Slice name, bool is_optional = true,
int64 default_value = 0) TD_WARN_UNUSED_RESULT;
Result<double> get_json_object_double_field(JsonObject &object, Slice name, bool is_optional = true,
double default_value = 0.0) TD_WARN_UNUSED_RESULT;
Result<string> get_json_object_string_field(JsonObject &object, Slice name, bool is_optional = true,
string default_value = "") TD_WARN_UNUSED_RESULT;
} // namespace td