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ArduinoJson/include/ArduinoJson/Internals/List.hpp
2014-11-08 21:16:47 +01:00

66 lines
1.8 KiB
C++

// Copyright Benoit Blanchon 2014
// MIT License
//
// Arduino JSON library
// https://github.com/bblanchon/ArduinoJson
#pragma once
#include "../JsonBuffer.hpp"
#include "ListConstIterator.hpp"
#include "ListIterator.hpp"
#include "PlacementNew.hpp"
namespace ArduinoJson {
namespace Internals {
// A singly linked list of T.
// The linked list is composed of ListNode<T>.
// It is derived by JsonArray and JsonObject
template <typename T>
class List {
public:
typedef T value_type;
typedef ListNode<T> node_type;
typedef ListIterator<T> iterator;
typedef ListConstIterator<T> const_iterator;
// Creates an empty List<T> attached to a JsonBuffer.
// The JsonBuffer allows to allocate new nodes.
// When buffer is NULL, the List is not able to grow and success() returns
// false. This is used to identify bad memory allocations and parsing
// failures.
explicit List(JsonBuffer *buffer) : _buffer(buffer), _firstNode(NULL) {}
// Returns true if the object is valid
// Would return false in the following situation:
// - the memory allocation failed (StaticJsonBuffer was too small)
// - the JSON parsing failed
bool success() const { return _buffer != NULL; }
// Returns the numbers of elements in the list.
// For a JsonObject, it would return the number of key-value pairs
int size() const;
iterator begin() { return iterator(_firstNode); }
iterator end() { return iterator(NULL); }
const_iterator begin() const { return const_iterator(_firstNode); }
const_iterator end() const { return const_iterator(NULL); }
protected:
node_type *createNode() {
if (!_buffer) return NULL;
void *ptr = _buffer->alloc(sizeof(node_type));
return ptr ? new (ptr) node_type() : NULL;
}
void addNode(node_type *node);
void removeNode(node_type *nodeToRemove);
JsonBuffer *_buffer;
node_type *_firstNode;
};
}
}