banan-os/BAN/BAN/String.cpp

#include <BAN/Errors.h>
#include <BAN/Math.h>
#include <BAN/Move.h>
#include <BAN/New.h>
#include <BAN/String.h>
#include <BAN/StringView.h>

#include <string.h>

namespace BAN
{

	String::String()
	{
		MUST(copy_impl(""sv));
	}

	String::String(const String& other)
	{
		MUST(copy_impl(other.sv()));
	}

	String::String(String&& other)
	{
		move_impl(move(other));
	}

	String::String(StringView other)
	{
		MUST(copy_impl(other));
	}

	String::~String()
	{
		BAN::deallocator(m_data);
	}

	String& String::operator=(const String& other)
	{
		MUST(copy_impl(other.sv()));
		return *this;
	}

	String& String::operator=(String&& other)
	{
		BAN::deallocator(m_data);
		move_impl(move(other));
		return *this;
	}

	String& String::operator=(StringView other)
	{
		MUST(copy_impl(other));
		return *this;
	}

	ErrorOr<void> String::push_back(char ch)
	{
		TRY(ensure_capacity(m_size + 2));
		m_data[m_size] = ch;
		m_size++;
		m_data[m_size] = '\0';
		return {};
	}

	ErrorOr<void> String::insert(char ch, size_type index)
	{
		ASSERT(index <= m_size);
		TRY(ensure_capacity(m_size + 1 + 1));
		memmove(m_data + index + 1, m_data + index, m_size - index);
		m_data[index] = ch;
		m_size += 1;
		m_data[m_size] = '\0';
		return {};
	}

	ErrorOr<void> String::insert(StringView other, size_type index)
	{
		ASSERT(index <= m_size);
		TRY(ensure_capacity(m_size + other.size() + 1));
		memmove(m_data + index + other.size(), m_data + index, m_size - index);
		memcpy(m_data + index, other.data(), other.size());
		m_size += other.size();
		m_data[m_size] = '\0';
		return {};
	}

	ErrorOr<void> String::append(StringView other)
	{
		TRY(ensure_capacity(m_size + other.size() + 1));
		memcpy(m_data + m_size, other.data(), other.size());
		m_size += other.size();
		m_data[m_size] = '\0';
		return {};
	}

	ErrorOr<void> String::append(const String& string)
	{
		TRY(append(string.sv()));
		return {};
	}

	void String::pop_back()
	{
		ASSERT(m_size > 0);
		m_size--;
		m_data[m_size] = '\0';
	}

	void String::remove(size_type index)
	{
		erase(index,  1);
	}

	void String::erase(size_type index, size_type count)
	{
		ASSERT(index + count <= m_size);
		memmove(m_data + index, m_data + index + count, m_size - index - count);
		m_size -= count;
		m_data[m_size] = '\0';
	}
	
	void String::clear()
	{
		m_size = 0;
		m_data[0] = '\0';
	}

	char String::operator[](size_type index) const
	{
		ASSERT(index < m_size);
		return m_data[index];
	}

	char& String::operator[](size_type index)
	{
		ASSERT(index < m_size);
		return m_data[index];
	}

	bool String::operator==(const String& other) const
	{
		if (m_size != other.m_size)
			return false;
		return memcmp(m_data, other.m_data, m_size) == 0;
	}

	bool String::operator==(StringView other) const
	{
		if (m_size != other.size())
			return false;
		return memcmp(m_data, other.data(), m_size) == 0;
	}

	bool String::operator==(const char* other) const
	{
		for (size_type i = 0; i <= m_size; i++)
			if (m_data[i] != other[i])
				return false;
		return true;
	}

	ErrorOr<void> String::resize(size_type size, char ch)
	{
		if (size < m_size)
		{
			m_data[size] = '\0';
			m_size = size;
		}
		else if (size > m_size)
		{
			TRY(ensure_capacity(size + 1));
			for (size_type i = m_size; i < size; i++)
				m_data[i] = ch;
			m_data[size] = '\0';
			m_size = size;
		}
		m_size = size;
		return {};
	}

	ErrorOr<void> String::reserve(size_type size)
	{
		TRY(ensure_capacity(size));
		return {};
	}

	ErrorOr<void> String::shrink_to_fit()
	{
		size_type temp = m_capacity;
		m_capacity = 0;
		auto error_or = ensure_capacity(m_size);
		if (error_or.is_error())
		{
			m_capacity = temp;
			return error_or;
		}
		return {};
	}

	StringView String::sv() const
	{
		return StringView(*this);
	}

	bool String::empty() const
	{
		return m_size == 0;
	}

	String::size_type String::size() const
	{
		return m_size;
	}

	String::size_type String::capacity() const
	{
		return m_capacity;
	}

	const char* String::data() const
	{
		return m_data;
	}

	ErrorOr<void> String::ensure_capacity(size_type size)
	{
		if (m_capacity >= size)
			return {};
		size_type new_cap = BAN::Math::max<size_type>(size, m_capacity * 2);
		void* new_data = BAN::allocator(new_cap);
		if (new_data == nullptr)
			return Error::from_errno(ENOMEM);
		if (m_data)
			memcpy(new_data, m_data, m_size + 1);
		BAN::deallocator(m_data);
		m_data = (char*)new_data;
		m_capacity = new_cap;
		return {};
	}

	ErrorOr<void> String::copy_impl(StringView other)
	{
		TRY(ensure_capacity(other.size() + 1));
		memcpy(m_data, other.data(), other.size());
		m_size = other.size();
		m_data[m_size] = '\0';
		return {};
	}

	void String::move_impl(String&& other)
	{
		m_data		= other.m_data;
		m_size		= other.m_size;
		m_capacity	= other.m_capacity;

		other.m_data = nullptr;
		other.m_size = 0;
		other.m_capacity = 0;
	}

}