json-parser-in-c-2/src/json_cpp.cpp

#include "json.h"
#include "json.hpp"
#include "json_collections.h"
#include <cstdint>
#include <cstring>
#include <memory>
#include <string>

namespace json {

class Underlying {
public:
    virtual auto ptr() -> struct json_value*& = 0;
    virtual auto ptr() const -> const struct json_value* const& = 0;
    virtual auto alloc_ptr() -> struct blockalloc* = 0;

private:
};

class ValuePtr final : public Underlying {
public:
    explicit ValuePtr(struct blockalloc* alloc, struct json_value* value)
        : m_alloc(alloc)
        , m_value(value) { };

    auto ptr() -> struct json_value*& override
    {
        return m_value;
    }
    auto ptr() const -> const struct json_value* const& override
    {
        return m_value;
    }

    auto alloc_ptr() -> struct blockalloc* override
    {
        return m_alloc;
    }

private:
    struct blockalloc* m_alloc;
    struct json_value* m_value;
};

auto Value::is(Type type) const -> bool
{
    return json_is(m_underlying->ptr(), (enum json_type)type);
}

auto Value::get_type() const -> Type
{
    return (Type)json_get_type(m_underlying->ptr());
}
auto Value::get_bool() const -> bool
{
    return json_get_bool(m_underlying->ptr());
}
auto Value::get_int() const -> std::int64_t
{
    return json_get_int(m_underlying->ptr());
}
auto Value::get_float() const -> double
{
    return json_get_float(m_underlying->ptr());
}
auto Value::get_string() const -> std::string_view
{
    return json_get_string(m_underlying->ptr());
}

void Value::set_null()
{
    json_set_null(&m_underlying->ptr());
}
void Value::set_bool(bool val)
{
    json_set_bool(&m_underlying->ptr(), val);
}
void Value::set_int(int64_t val)
{
    json_set_int(&m_underlying->ptr(), val);
}
void Value::set_float(double val)
{
    json_set_float(&m_underlying->ptr(), val);
}
void Value::set_string(std::string_view val)
{
    char* own_str
        = (char*)blockalloc_alloc(m_underlying->alloc_ptr(), val.size() + 1, 2);
    std::strncpy(own_str, val.data(), val.size() + 1);
    json_set_string(m_underlying->ptr(), own_str);
}

auto Value::count() const -> std::size_t
{
    return json_array_count(m_underlying->ptr());
}
auto Value::get(std::size_t idx) -> std::unique_ptr<Value>
{
    return std::make_unique<Value>(std::make_unique<ValuePtr>(
        m_underlying->alloc_ptr(), json_idx(m_underlying->ptr(), idx)));
}
auto Value::get(std::size_t idx) const -> std::unique_ptr<const Value>
{
    return std::make_unique<Value>(std::make_unique<ValuePtr>(
        m_underlying->alloc_ptr(), json_idx(m_underlying->ptr(), idx)));
}
void Value::push(std::unique_ptr<Value> value)
{
    json_push(m_underlying->ptr(), value->m_underlying->ptr());
}

auto Value::get(std::string_view key) -> std::unique_ptr<Value>
{
    return std::make_unique<Value>(
        std::make_unique<ValuePtr>(m_underlying->alloc_ptr(),
            json_key_sized(m_underlying->ptr(), key.data(), key.size())));
}
auto Value::get(std::string_view key) const -> std::unique_ptr<const Value>
{
    return std::make_unique<Value>(
        std::make_unique<ValuePtr>(m_underlying->alloc_ptr(),
            json_key_sized(m_underlying->ptr(), key.data(), key.size())));
}
void Value::set(std::string_view key, std::unique_ptr<Value> value)
{
    json_set_sized(m_underlying->ptr(),
        key.data(),
        key.size(),
        value->m_underlying->ptr());
}

auto Value::query(const std::string& query) -> std::unique_ptr<Value>
{
    return std::make_unique<Value>(
        std::make_unique<ValuePtr>(m_underlying->alloc_ptr(),
            json_query(m_underlying->ptr(), query.c_str())));
}

class Doc final : public Underlying {
public:
    explicit Doc()
    {
        blockalloc_construct(&m_alloc);
    }

    ~Doc()
    {
        blockalloc_destroy(&m_alloc);
        if (m_value) {
            json_free(m_value);
        }
    }

    int parse(std::string_view text)
    {
        m_value = json_parse(text.data(), text.size(), &m_alloc);
        if (!m_value)
            return 1;
        return 0;
    }

    auto ptr() -> struct json_value*& override
    {
        return m_value;
    }
    auto ptr() const -> const struct json_value* const& override
    {
        return m_value;
    }

    auto alloc_ptr() -> struct blockalloc* override
    {
        return &m_alloc;
    }

private:
    struct blockalloc m_alloc;
    struct json_value* m_value = nullptr;
};

auto parse(std::string_view text) -> std::unique_ptr<Value>
{
    auto doc = std::make_unique<Doc>();
    if (doc->parse(text) != 0)
        return nullptr;
    return std::make_unique<Value>(std::move(doc));
}

}