Split <totalSize> by <partSize>

PartSlicer.h

#pragma once

class PartSlicer
{
public:
	PartSlicer(size_t totalSize, size_t partSize) : totalSize(totalSize), partSize(partSize), offset(0) {}

	void nextPart()
	{
		if (offset < totalSize)
			offset += partSize;
	}

	size_t getPartIndex() const
	{
		return (offset / partSize);
	}

	bool hasData() const
	{
		return (offset < totalSize);
	}

	size_t getOffset() const
	{
		return (offset > totalSize) ? totalSize : offset;
	}

	size_t getPartSize() const
	{
		size_t result = totalSize - getOffset();
		if (result > partSize)
			result = partSize;
		return result;
	}

	size_t getPartCount() const
	{
		return (totalSize + partSize - 1) / partSize;
	}

	size_t getPartLeft() const
	{
		return (getPartCount() - getPartIndex());
	}

	float getProgress() const
	{
		return getOffset() * 100.f / totalSize;
	}

private:
	size_t totalSize;
	size_t partSize;
	size_t offset;
};