Node / meshtastic / Meshtastic-Android / files / core / takserver / src / commonTest / kotlin / org / meshtastic / core / takserver / fountain / FountainCodecTest.kt

Displaying Raw • Download

T8b949e/*

* Copyright (c) 2026 Meshtastic LLC

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <https://www.gnu.org/licenses/>.

*/

Tff7b72package T7ee787org.meshtastic.core.takserver.fountain

Tff7b72import T7ee787kotlin.test.Test

Tff7b72import T7ee787kotlin.test.assertContentEquals

Tff7b72import T7ee787kotlin.test.assertEquals

Tff7b72import T7ee787kotlin.test.assertFalse

Tff7b72import T7ee787kotlin.test.assertNotNull

Tff7b72import T7ee787kotlin.test.assertNull

Tff7b72import T7ee787kotlin.test.assertTrue

Tff7b72class T56d364FountainCodecTest Tb4b4b4{

Tff7b72private Tff7b72fun Td2a8ffcreateCodecTb4b4b4(Tb4b4b4) Tff7b72= Te6edf3FountainCodecTb4b4b4(Tb4b4b4)

Tf0883e@Test

Tff7b72fun Td2a8ff`test encode and decode small payload`Tb4b4b4(Tb4b4b4) Tb4b4b4{

Tff7b72val Te6edf3codec Tff7b72= Te6edf3createCodecTb4b4b4(Tb4b4b4)

Tff7b72val Te6edf3originalData Tff7b72= Ta5d6ff"Ta5d6ffHello, TAK! This is a test payload.Ta5d6ff"Tb4b4b4.Te6edf3encodeToByteArrayTb4b4b4(Tb4b4b4)

T8b949e// Use a fixed transfer ID for deterministic peeling decode

Tff7b72val Te6edf3transferId Tff7b72= T79c0ff4T79c0ff2

Tff7b72val Te6edf3packets Tff7b72= Te6edf3codecTb4b4b4.Te6edf3encodeTb4b4b4(Te6edf3originalDataTb4b4b4, Te6edf3transferIdTb4b4b4)

Te6edf3assertTrueTb4b4b4(Te6edf3packetsTb4b4b4.Te6edf3isNotEmptyTb4b4b4(Tb4b4b4)Tb4b4b4, Ta5d6ff"Ta5d6ffEncoding should produce packetsTa5d6ff"Tb4b4b4)

Tff7b72var Te6edf3decodedResultTb4b4b4: Te6edf3PairTff7b72<Te6edf3ByteArrayTb4b4b4, Tffa657IntTff7b72>Tff7b72? Tff7b72= Tff7b72null

Tff7b72for Tb4b4b4(Te6edf3packet Tff7b72in Te6edf3packetsTb4b4b4) Tb4b4b4{

Tff7b72val Te6edf3result Tff7b72= Te6edf3codecTb4b4b4.Te6edf3handleIncomingPacketTb4b4b4(Te6edf3packetTb4b4b4)

Tff7b72if Tb4b4b4(Te6edf3result Tff7b72!Tff7b72= Tff7b72nullTb4b4b4) Tb4b4b4{

Te6edf3decodedResult Tff7b72= Te6edf3result

Tff7b72break

Tb4b4b4}

Tb4b4b4}

Te6edf3assertNotNullTb4b4b4(Te6edf3decodedResultTb4b4b4, Ta5d6ff"Ta5d6ffShould successfully decode payloadTa5d6ff"Tb4b4b4)

Te6edf3assertEqualsTb4b4b4(Te6edf3transferIdTb4b4b4, Te6edf3decodedResultTb4b4b4.Te6edf3secondTb4b4b4, Ta5d6ff"Ta5d6ffTransfer ID should matchTa5d6ff"Tb4b4b4)

Te6edf3assertContentEqualsTb4b4b4(Te6edf3originalDataTb4b4b4, Te6edf3decodedResultTb4b4b4.Te6edf3firstTb4b4b4, Ta5d6ff"Ta5d6ffDecoded data should match originalTa5d6ff"Tb4b4b4)

Tb4b4b4}

Tf0883e@Test

Tff7b72fun Td2a8ff`test encode and decode larger payload with packet loss`Tb4b4b4(Tb4b4b4) Tb4b4b4{

Tff7b72val Te6edf3codec Tff7b72= Te6edf3createCodecTb4b4b4(Tb4b4b4)

T8b949e// Create a payload larger than BLOCK_SIZE (220 bytes)

Tff7b72val Te6edf3originalData Tff7b72= Te6edf3ByteArrayTb4b4b4(T79c0ff1T79c0ff0T79c0ff2T79c0ff4Tb4b4b4) Tb4b4b4{ Tb4b4b4(Tffa657it Tff7b72% T79c0ff2T79c0ff5T79c0ff6Tb4b4b4)Tb4b4b4.Te6edf3toByteTb4b4b4(Tb4b4b4) Tb4b4b4}

T8b949e// Use a fixed transfer ID for deterministic peeling decode.

T8b949e// Random transfer IDs cause ~14% flake rate because the robust soliton

T8b949e// distribution with k=5 and 50% overhead doesn't always produce a

T8b949e// decodable set of encoded blocks via the peeling algorithm.

Tff7b72val Te6edf3transferId Tff7b72= T79c0ff4T79c0ff2

Tff7b72val Te6edf3packets Tff7b72= Te6edf3codecTb4b4b4.Te6edf3encodeTb4b4b4(Te6edf3originalDataTb4b4b4, Te6edf3transferIdTb4b4b4)

Te6edf3assertTrueTb4b4b4(Te6edf3packetsTb4b4b4.Te6edf3size Tff7b72> T79c0ff4Tb4b4b4, Ta5d6ff"Ta5d6ffShould have multiple packets for large payloadTa5d6ff"Tb4b4b4)

Tff7b72var Te6edf3decodedResultTb4b4b4: Te6edf3PairTff7b72<Te6edf3ByteArrayTb4b4b4, Tffa657IntTff7b72>Tff7b72? Tff7b72= Tff7b72null

T8b949e// Process all packets - fountain codes are designed to handle packet loss

T8b949e// by receiving enough encoded packets to reconstruct the original data

Tff7b72for Tb4b4b4(Te6edf3packet Tff7b72in Te6edf3packetsTb4b4b4) Tb4b4b4{

Tff7b72val Te6edf3result Tff7b72= Te6edf3codecTb4b4b4.Te6edf3handleIncomingPacketTb4b4b4(Te6edf3packetTb4b4b4)

Tff7b72if Tb4b4b4(Te6edf3result Tff7b72!Tff7b72= Tff7b72nullTb4b4b4) Tb4b4b4{

Te6edf3decodedResult Tff7b72= Te6edf3result

Tff7b72break

Tb4b4b4}

Tb4b4b4}

Te6edf3assertNotNullTb4b4b4(Te6edf3decodedResultTb4b4b4, Ta5d6ff"Ta5d6ffShould successfully decode payload with sufficient packetsTa5d6ff"Tb4b4b4)

Te6edf3assertEqualsTb4b4b4(Te6edf3transferIdTb4b4b4, Te6edf3decodedResultTb4b4b4.Te6edf3secondTb4b4b4, Ta5d6ff"Ta5d6ffTransfer ID should matchTa5d6ff"Tb4b4b4)

Te6edf3assertContentEqualsTb4b4b4(Te6edf3originalDataTb4b4b4, Te6edf3decodedResultTb4b4b4.Te6edf3firstTb4b4b4, Ta5d6ff"Ta5d6ffDecoded data should match originalTa5d6ff"Tb4b4b4)

Tb4b4b4}

Tf0883e@Test

Tff7b72fun Td2a8ff`test build and parse ACK`Tb4b4b4(Tb4b4b4) Tb4b4b4{

Tff7b72val Te6edf3codec Tff7b72= Te6edf3createCodecTb4b4b4(Tb4b4b4)

Tff7b72val Te6edf3transferId Tff7b72= T79c0ff1T79c0ff2T79c0ff3T79c0ff4T79c0ff5T79c0ff6

Tff7b72val Te6edf3type Tff7b72= Te6edf3FountainConstantsTb4b4b4.Te6edf3ACK_TYPE_COMPLETE

Tff7b72val Te6edf3received Tff7b72= T79c0ff5

Tff7b72val Te6edf3needed Tff7b72= T79c0ff0

Tff7b72val Te6edf3dataHash Tff7b72= Te6edf3byteArrayOfTb4b4b4(T79c0ff1Tb4b4b4, T79c0ff2Tb4b4b4, T79c0ff3Tb4b4b4, T79c0ff4Tb4b4b4, T79c0ff5Tb4b4b4, T79c0ff6Tb4b4b4, T79c0ff7Tb4b4b4, T79c0ff8Tb4b4b4)

Tff7b72val Te6edf3ackPacket Tff7b72= Te6edf3codecTb4b4b4.Te6edf3buildAckTb4b4b4(Te6edf3transferIdTb4b4b4, Te6edf3typeTb4b4b4, Te6edf3receivedTb4b4b4, Te6edf3neededTb4b4b4, Te6edf3dataHashTb4b4b4)

Te6edf3assertTrueTb4b4b4(Te6edf3codecTb4b4b4.Te6edf3isFountainPacketTb4b4b4(Te6edf3ackPacketTb4b4b4)Tb4b4b4, Ta5d6ff"Ta5d6ffACK should be recognized as a Fountain packetTa5d6ff"Tb4b4b4)

Tff7b72val Te6edf3parsedAck Tff7b72= Te6edf3codecTb4b4b4.Te6edf3parseAckTb4b4b4(Te6edf3ackPacketTb4b4b4)

Te6edf3assertNotNullTb4b4b4(Te6edf3parsedAckTb4b4b4, Ta5d6ff"Ta5d6ffACK should be parseableTa5d6ff"Tb4b4b4)

Te6edf3assertEqualsTb4b4b4(Te6edf3transferIdTb4b4b4, Te6edf3parsedAckTb4b4b4.Te6edf3transferIdTb4b4b4)

Te6edf3assertEqualsTb4b4b4(Te6edf3typeTb4b4b4, Te6edf3parsedAckTb4b4b4.Te6edf3typeTb4b4b4)

Te6edf3assertEqualsTb4b4b4(Te6edf3receivedTb4b4b4, Te6edf3parsedAckTb4b4b4.Te6edf3receivedTb4b4b4)

Te6edf3assertEqualsTb4b4b4(Te6edf3neededTb4b4b4, Te6edf3parsedAckTb4b4b4.Te6edf3neededTb4b4b4)

Te6edf3assertContentEqualsTb4b4b4(Te6edf3dataHashTb4b4b4, Te6edf3parsedAckTb4b4b4.Te6edf3dataHashTb4b4b4)

Tb4b4b4}

Tf0883e@Test

Tff7b72fun Td2a8ff`test invalid packet handling`Tb4b4b4(Tb4b4b4) Tb4b4b4{

Tff7b72val Te6edf3codec Tff7b72= Te6edf3createCodecTb4b4b4(Tb4b4b4)

Tff7b72val Te6edf3invalidPacket Tff7b72= Te6edf3byteArrayOfTb4b4b4(T79c0ff0Te6edf3x00Tb4b4b4, T79c0ff0Te6edf3x01Tb4b4b4, T79c0ff0Te6edf3x02Tb4b4b4, T79c0ff0Te6edf3x03Tb4b4b4)

Te6edf3assertFalseTb4b4b4(Te6edf3codecTb4b4b4.Te6edf3isFountainPacketTb4b4b4(Te6edf3invalidPacketTb4b4b4)Tb4b4b4, Ta5d6ff"Ta5d6ffShould reject invalid magic bytesTa5d6ff"Tb4b4b4)

Te6edf3assertNullTb4b4b4(Te6edf3codecTb4b4b4.Te6edf3parseDataHeaderTb4b4b4(Te6edf3invalidPacketTb4b4b4)Tb4b4b4, Ta5d6ff"Ta5d6ffShould not parse invalid headerTa5d6ff"Tb4b4b4)

Te6edf3assertNullTb4b4b4(Te6edf3codecTb4b4b4.Te6edf3handleIncomingPacketTb4b4b4(Te6edf3invalidPacketTb4b4b4)Tb4b4b4, Ta5d6ff"Ta5d6ffShould handle invalid packet gracefullyTa5d6ff"Tb4b4b4)

Tb4b4b4}

Tb4b4b4}