Livt.Net

tests/tftp/TftpTestSink.lvt

namespace Livt.Net.Tests

using Livt.Net

/**
 * Transactional upload double with explicit reset and commit failure injection.
 */
component TftpTestSink : ITftpWriteSink
{
	// Borrowed staging shared with the protocol engine.
	upload: ITftpUploadBuffer

	/**
	 * Borrows the same staging instance as the tested server.
	 */
	new(upload: ITftpUploadBuffer)
	{
		this.upload = upload
	}

	// Test observations and injected commit failure.
	public begins: int
	public writes: int
	public bytes: int
	public commits: int
	public aborts: int
	public rejectCommit: bool
	public rejectWriteAt: int
	public firstByte: byte
	public checksum: int
	public largestChunk: int

	/**
	 * Clears observations between tests after the protocol owner has reset.
	 */
	public fn Reset()
	{
		begins = 0
		writes = 0
		bytes = 0
		commits = 0
		aborts = 0
		rejectCommit = false
		rejectWriteAt = 0
		checksum = 0
		largestChunk = 0
	}

	/**
	 * Accepts a nonempty filename.
	 */
	override fn Begin(length: int) bool
	{
		begins++
		return length > 0
	}

	/**
	 * Counts each accepted chunk and captures its first byte when present.
	 */
	override fn Write(length: int) bool
	{
		writes++

		if (rejectWriteAt == writes) {
			return false
		}

		bytes = bytes + length

		if (length > largestChunk) {
			largestChunk = length
		}

		for (var index = 0; index < length; index++) {
			checksum = checksum + (upload.GetDataByte(index) as int)
		}

		if (length > 0) {
			firstByte = upload.GetDataByte(0)
		}

		return true
	}

	/**
	 * Records successful commit unless the test injects a validation failure.
	 */
	override fn Commit() bool
	{
		if (rejectCommit) {
			return false
		}

		commits++
		return true
	}

	/**
	 * Counts cancellation without touching previously committed data.
	 */
	override fn Abort()
	{
		aborts++
	}
}