Livt.FileSystems

src/ISectorBuffer.lvt

namespace Livt.FileSystems

/**
 * One retained 512-byte sector. A single scheduled owner serializes all calls.
 * An accepted Start invalidates the previous sector; Service advances copying without waiting
 * for device completion. Cancellation drains the device before busy clears.
 * Reads require valid; reset invalidates metadata without clearing payload RAM.
 */
interface ISectorBuffer
{
	// Retained copy/cancellation state and visibility of the current sector.
	public busy: bool
	public valid: bool
	public failed: bool

	/**
	 * Starts one bounded sector read; false leaves ownership unchanged.
	 */
	fn Start(lba: uint) bool

	/**
	 * Advances at most one byte of copying or cancellation.
	 */
	fn Service()

	/**
	 * Requests cancellation and invalidates retained content.
	 */
	fn Cancel()

	/**
	 * Returns a byte at offset 0..511; invalid accesses return zero.
	 */
	fn ReadByte(offset: int) byte

	/**
	 * Returns a little-endian word; requires valid and offset 0..510.
	 */
	fn Read16(offset: int) uint

	/**
	 * Returns a little-endian double word; requires valid and offset 0..508.
	 */
	fn Read32(offset: int) uint
}