rippled/include/xrpl/beast/utility/PropertyStream.h

#ifndef BEAST_UTILITY_PROPERTYSTREAM_H_INCLUDED
#define BEAST_UTILITY_PROPERTYSTREAM_H_INCLUDED

#include <xrpl/beast/core/List.h>

#include <mutex>
#include <sstream>
#include <string>

namespace beast {

//------------------------------------------------------------------------------

/** Abstract stream with RAII containers that produce a property tree. */
class PropertyStream
{
public:
    class Map;
    class Set;
    class Source;

    PropertyStream() = default;
    virtual ~PropertyStream() = default;

protected:
    virtual void
    map_begin() = 0;
    virtual void
    map_begin(std::string const& key) = 0;
    virtual void
    map_end() = 0;

    virtual void
    add(std::string const& key, std::string const& value) = 0;

    void
    add(std::string const& key, char const* value)
    {
        add(key, std::string(value));
    }

    template <typename Value>
    void
    lexical_add(std::string const& key, Value value)
    {
        std::stringstream ss;
        ss << value;
        add(key, ss.str());
    }

    virtual void
    add(std::string const& key, bool value);
    virtual void
    add(std::string const& key, char value);
    virtual void
    add(std::string const& key, signed char value);
    virtual void
    add(std::string const& key, unsigned char value);
    virtual void
    add(std::string const& key, short value);
    virtual void
    add(std::string const& key, unsigned short value);
    virtual void
    add(std::string const& key, int value);
    virtual void
    add(std::string const& key, unsigned int value);
    virtual void
    add(std::string const& key, long value);
    virtual void
    add(std::string const& key, unsigned long value);
    virtual void
    add(std::string const& key, long long value);
    virtual void
    add(std::string const& key, unsigned long long value);
    virtual void
    add(std::string const& key, float value);
    virtual void
    add(std::string const& key, double value);
    virtual void
    add(std::string const& key, long double value);

    virtual void
    array_begin() = 0;
    virtual void
    array_begin(std::string const& key) = 0;
    virtual void
    array_end() = 0;

    virtual void
    add(std::string const& value) = 0;

    void
    add(char const* value)
    {
        add(std::string(value));
    }

    template <typename Value>
    void
    lexical_add(Value value)
    {
        std::stringstream ss;
        ss << value;
        add(ss.str());
    }

    virtual void
    add(bool value);
    virtual void
    add(char value);
    virtual void
    add(signed char value);
    virtual void
    add(unsigned char value);
    virtual void
    add(short value);
    virtual void
    add(unsigned short value);
    virtual void
    add(int value);
    virtual void
    add(unsigned int value);
    virtual void
    add(long value);
    virtual void
    add(unsigned long value);
    virtual void
    add(long long value);
    virtual void
    add(unsigned long long value);
    virtual void
    add(float value);
    virtual void
    add(double value);
    virtual void
    add(long double value);

private:
    class Item;
    class Proxy;
};

//------------------------------------------------------------------------------
//
// Item
//
//------------------------------------------------------------------------------

class PropertyStream::Item : public List<Item>::Node
{
public:
    explicit Item(Source* source);
    Source&
    source() const;
    Source*
    operator->() const;
    Source&
    operator*() const;

private:
    Source* m_source;
};

//------------------------------------------------------------------------------
//
// Proxy
//
//------------------------------------------------------------------------------

class PropertyStream::Proxy
{
private:
    Map const* m_map;
    std::string m_key;
    std::ostringstream mutable m_ostream;

public:
    Proxy(Map const& map, std::string const& key);
    Proxy(Proxy const& other);
    ~Proxy();

    template <typename Value>
    Proxy&
    operator=(Value value);

    std::ostream&
    operator<<(std::ostream& manip(std::ostream&)) const;

    template <typename T>
    std::ostream&
    operator<<(T const& t) const
    {
        return m_ostream << t;
    }
};

//------------------------------------------------------------------------------
//
// Map
//
//------------------------------------------------------------------------------

class PropertyStream::Map
{
private:
    PropertyStream& m_stream;

public:
    explicit Map(PropertyStream& stream);
    explicit Map(Set& parent);
    Map(std::string const& key, Map& parent);
    Map(std::string const& key, PropertyStream& stream);
    ~Map();

    Map(Map const&) = delete;
    Map&
    operator=(Map const&) = delete;

    PropertyStream&
    stream();
    PropertyStream const&
    stream() const;

    template <typename Value>
    void
    add(std::string const& key, Value value) const
    {
        m_stream.add(key, value);
    }

    template <typename Key, typename Value>
    void
    add(Key key, Value value) const
    {
        std::stringstream ss;
        ss << key;
        add(ss.str(), value);
    }

    Proxy
    operator[](std::string const& key);

    Proxy
    operator[](char const* key)
    {
        return Proxy(*this, key);
    }

    template <typename Key>
    Proxy
    operator[](Key key) const
    {
        std::stringstream ss;
        ss << key;
        return Proxy(*this, ss.str());
    }
};

//--------------------------------------------------------------------------

template <typename Value>
PropertyStream::Proxy&
PropertyStream::Proxy::operator=(Value value)
{
    m_map->add(m_key, value);
    return *this;
}

//--------------------------------------------------------------------------
//
// Set
//
//------------------------------------------------------------------------------

class PropertyStream::Set
{
private:
    PropertyStream& m_stream;

public:
    Set(std::string const& key, Map& map);
    Set(std::string const& key, PropertyStream& stream);
    ~Set();

    Set(Set const&) = delete;
    Set&
    operator=(Set const&) = delete;

    PropertyStream&
    stream();
    PropertyStream const&
    stream() const;

    template <typename Value>
    void
    add(Value value) const
    {
        m_stream.add(value);
    }
};

//------------------------------------------------------------------------------
//
// Source
//
//------------------------------------------------------------------------------

/** Subclasses can be called to write to a stream and have children. */
class PropertyStream::Source
{
private:
    std::string const m_name;
    std::recursive_mutex lock_;
    Item item_;
    Source* parent_;
    List<Item> children_;

public:
    explicit Source(std::string const& name);
    virtual ~Source();

    Source(Source const&) = delete;
    Source&
    operator=(Source const&) = delete;

    /** Returns the name of this source. */
    std::string const&
    name() const;

    /** Add a child source. */
    void
    add(Source& source);

    /** Add a child source by pointer.
        The source pointer is returned so it can be used in ctor-initializers.
    */
    template <class Derived>
    Derived*
    add(Derived* child)
    {
        add(*static_cast<Source*>(child));
        return child;
    }

    /** Remove a child source from this Source. */
    void
    remove(Source& child);

    /** Remove all child sources from this Source. */
    void
    removeAll();

    /** Write only this Source to the stream. */
    void
    write_one(PropertyStream& stream);

    /** write this source and all its children recursively to the stream. */
    void
    write(PropertyStream& stream);

    /** Parse the path and write the corresponding Source and optional children.
        If the source is found, it is written. If the wildcard character '*'
        exists as the last character in the path, then all the children are
        written recursively.
    */
    void
    write(PropertyStream& stream, std::string const& path);

    /** Parse the dot-delimited Source path and return the result.
        The first value will be a pointer to the Source object corresponding
        to the given path. If no Source object exists, then the first value
        will be nullptr and the second value will be undefined.
        The second value is a boolean indicating whether or not the path string
        specifies the wildcard character '*' as the last character.

        print statement examples
        "parent.child" prints child and all of its children
        "parent.child." start at the parent and print down to child
        "parent.grandchild" prints nothing- grandchild not direct discendent
        "parent.grandchild." starts at the parent and prints down to grandchild
        "parent.grandchild.*" starts at parent, print through grandchild
       children
    */
    std::pair<Source*, bool>
    find(std::string path);

    Source*
    find_one_deep(std::string const& name);
    PropertyStream::Source*
    find_path(std::string path);
    PropertyStream::Source*
    find_one(std::string const& name);

    static bool
    peel_leading_slash(std::string* path);
    static bool
    peel_trailing_slashstar(std::string* path);
    static std::string
    peel_name(std::string* path);

    //--------------------------------------------------------------------------

    /** Subclass override.
        The default version does nothing.
    */
    virtual void
    onWrite(Map&);
};

}  // namespace beast

#endif