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Adding UnixTimestamp + Parse message type 27 #149

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Adding UnixTimestamp + Parse message type 27 #149

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0f850eb
Add Timestamp from NMEA message to each message type
josh-dadswell-hackney May 6, 2022
05f38c8
revert mistake
josh-dadswell-hackney May 6, 2022
c968667
Merge pull request #2 from joshdadswellijyi/Add_Timestamp
joshdadswellijyi May 6, 2022
f8c9973
Merge branch 'ais-dotnet:master' into master
joshdadswellijyi Jun 22, 2022
d729321
Parse message type 27
josh-dadswell-hackney Jun 22, 2022
5a1a1c2
Merge pull request #3 from joshdadswellijyi/ParseMessageType27
joshdadswellijyi Jun 22, 2022
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2 changes: 1 addition & 1 deletion Solutions/Ais.Net.Models/Ais/Net/Models/Abstractions/IAisMessage.cs
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Expand Up @@ -4,7 +4,7 @@

namespace Ais.Net.Models.Abstractions
{
public interface IAisMessage : IVesselIdentity, IAisMessageType
public interface IAisMessage : IVesselIdentity, IAisMessageType, ITimestamp
{
}
}
17 changes: 17 additions & 0 deletions Solutions/Ais.Net.Models/Ais/Net/Models/Abstractions/IAisMessageType27.cs
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@@ -0,0 +1,17 @@
namespace Ais.Net.Models.Abstractions
{
public interface IAisMessageType27
{
float? CourseOverGroundDegrees { get; }

bool NotGnssPosition { get; }

NavigationStatus NavigationStatus { get; }

Position? Position { get; }

bool PositionAccuracy { get; }

float? SpeedOverGround { get; }
}
}
6 changes: 6 additions & 0 deletions Solutions/Ais.Net.Models/Ais/Net/Models/Abstractions/ITimestamp.cs
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@@ -0,0 +1,6 @@
namespace Ais.Net.Models.Abstractions;

public interface ITimestamp
{
public long? UnixTimestamp { get; }
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Unix timestamps come in two different units: seconds and milliseconds. I don't know which this is. Please could you rename it to make the units clear?

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I was simply using the field name that you had used to maintain continuity but can rename if desired?

https://github.com/ais-dotnet/Ais.Net/blob/3f0624713cd879f0234b167e9e77b899765e8843/Solutions/Ais.Net/Ais/Net/NmeaTagBlockParser.cs#L141

}
2 changes: 2 additions & 0 deletions Solutions/Ais.Net.Models/Ais/Net/Models/Abstractions/Position.cs
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Expand Up @@ -8,5 +8,7 @@ public record Position(double Latitude, double Longitude)
{
public static Position From10000thMins(int latitude, int longitude) =>
new (latitude.From10000thMinsToDegrees(), longitude.From10000thMinsToDegrees());
public static Position From10thMins(int latitude, int longitude) =>
new (latitude.From10thMinsToDegrees(), longitude.From10thMinsToDegrees());
}
}
2 changes: 1 addition & 1 deletion Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageBase.cs
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Expand Up @@ -6,5 +6,5 @@ namespace Ais.Net.Models
{
using Ais.Net.Models.Abstractions;

public record AisMessageBase(int MessageType, uint Mmsi) : IAisMessage;
public record AisMessageBase(int MessageType, uint Mmsi, long? UnixTimestamp) : IAisMessage;
}
5 changes: 5 additions & 0 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageExtensions.cs
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Expand Up @@ -14,6 +14,11 @@ public static double From10000thMinsToDegrees(this int value)
{
return value / 600000.0;
}

public static double From10thMinsToDegrees(this int value)
{
return value / 600.0;
}

public static float? FromTenths(this uint value)
{
Expand Down
5 changes: 3 additions & 2 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType18.cs
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Expand Up @@ -24,8 +24,9 @@ public record AisMessageType18(
uint RepeatIndicator,
float? SpeedOverGround,
uint TimeStampSecond,
uint TrueHeadingDegrees) :
AisMessageBase(MessageType: 18, Mmsi),
uint TrueHeadingDegrees,
long? UnixTimestamp) :
AisMessageBase(MessageType: 18, Mmsi, UnixTimestamp),
IAisMessageType18,
IAisIsAssigned,
IRaimFlag,
Expand Down
5 changes: 3 additions & 2 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType19.cs
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Expand Up @@ -27,8 +27,9 @@ public record AisMessageType19(
uint Spare308,
float? SpeedOverGround,
uint TimeStampSecond,
uint TrueHeadingDegrees) :
AisMessageBase(MessageType: 19, Mmsi),
uint TrueHeadingDegrees,
long? UnixTimestamp) :
AisMessageBase(MessageType: 19, Mmsi, UnixTimestamp),
IAisMessageType19,
IAisIsAssigned,
IAisIsDteNotReady,
Expand Down
5 changes: 3 additions & 2 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType1Through3.cs
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Expand Up @@ -23,8 +23,9 @@ public record AisMessageType1Through3(
uint SpareBits145,
float? SpeedOverGround,
uint TimeStampSecond,
uint TrueHeadingDegrees) :
AisMessageBase(MessageType, Mmsi),
uint TrueHeadingDegrees,
long? UnixTimestamp) :
AisMessageBase(MessageType, Mmsi, UnixTimestamp),
IAisMessageType1to3,
IRaimFlag,
IRepeatIndicator,
Expand Down
5 changes: 3 additions & 2 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType24Part0.cs
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Expand Up @@ -10,8 +10,9 @@ public record AisMessageType24Part0(
uint Mmsi,
uint PartNumber,
uint RepeatIndicator,
uint Spare160) :
AisMessageBase(MessageType: 24, Mmsi),
uint Spare160,
long? UnixTimestamp) :
AisMessageBase(MessageType: 24, Mmsi, UnixTimestamp),
IAisMultipartMessage,
IRepeatIndicator,
IAisMessageType24Part0;
Expand Down
5 changes: 3 additions & 2 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType24Part1.cs
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Expand Up @@ -21,8 +21,9 @@ public record AisMessageType24Part1(
ShipType ShipType,
uint UnitModelCode,
string VendorIdRev3,
string VendorIdRev4) :
AisMessageBase(MessageType: 24, Mmsi),
string VendorIdRev4,
long? UnixTimestamp) :
AisMessageBase(MessageType: 24, Mmsi, UnixTimestamp),
IAisMessageType24Part1,
IAisMultipartMessage,
ICallSign,
Expand Down
24 changes: 24 additions & 0 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType27.cs
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@@ -0,0 +1,24 @@
// <copyright file="AisMessageType18.cs" company="Endjin Limited">
// Copyright (c) Endjin Limited. All rights reserved.
// </copyright>

namespace Ais.Net.Models
{
using Ais.Net.Models.Abstractions;

public record AisMessageType27(
float? CourseOverGroundDegrees,
bool NotGnssPosition,
uint Mmsi,
NavigationStatus NavigationStatus,
Position? Position,
bool PositionAccuracy,
bool RaimFlag,
uint RepeatIndicator,
float? SpeedOverGround,
long? UnixTimestamp) :
AisMessageBase(MessageType: 27, Mmsi, UnixTimestamp),
IAisMessageType27,
IRaimFlag,
IRepeatIndicator;
}
5 changes: 3 additions & 2 deletions Solutions/Ais.Net.Models/Ais/Net/Models/AisMessageType5.cs
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Expand Up @@ -26,8 +26,9 @@ public record AisMessageType5(
uint RepeatIndicator,
ShipType ShipType,
uint Spare423,
string VesselName) :
AisMessageBase(MessageType: 5, Mmsi),
string VesselName,
long? UnixTimestamp) :
AisMessageBase(MessageType: 5, Mmsi, UnixTimestamp),
IAisMessageType5,
IAisIsDteNotReady,
IAisPositionFixType,
Expand Down
63 changes: 47 additions & 16 deletions Solutions/Ais.Net.Receiver/Ais/Net/Receiver/Parser/NmeaToAisMessageTypeProcessor.cs
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Expand Up @@ -30,31 +30,37 @@ public void OnNext(in NmeaLineParser parsedLine, in ReadOnlySpan<byte> asciiPayl
{
case >= 1 and <= 3:
{
this.ParseMessageTypes1Through3(asciiPayload, padding, messageType);
this.ParseMessageTypes1Through3(parsedLine, asciiPayload, padding, messageType);
return;
}

case 5:
{
this.ParseMessageType5(asciiPayload, padding);
this.ParseMessageType5(parsedLine, asciiPayload, padding);
return;
}

case 18:
{
this.ParseMessageType18(asciiPayload, padding);
this.ParseMessageType18(parsedLine, asciiPayload, padding);
return;
}

case 19:
{
this.ParseMessageType19(asciiPayload, padding);
this.ParseMessageType19(parsedLine, asciiPayload, padding);
return;
}

case 24:
{
this.ParseMessageType24(asciiPayload, padding);
this.ParseMessageType24(parsedLine, asciiPayload, padding);
return;
}

case 27:
{
this.ParseMessageType27(parsedLine, asciiPayload, padding);
return;
}
}
Expand Down Expand Up @@ -87,7 +93,7 @@ public void Progress(
throw new NotImplementedException();
}

private void ParseMessageTypes1Through3(ReadOnlySpan<byte> asciiPayload, uint padding, int messageType)
private void ParseMessageTypes1Through3(NmeaLineParser nmeaLineParser, ReadOnlySpan<byte> asciiPayload, uint padding, int messageType)
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The fact that we're now passing in a line parser and the ASCII payload seemed like a code smell to me, and now has me wondering: is there a layering issue here?

The timestamp isn't really part of the AIS message, it's actually from the surrounding NMEA layer, isn't it?

Before this change, these various message types represent the information that was broadcast by the vessels' AIS systems. The timestamp is not part of that. The provenance of the timestamp is not necessarily clear. It might tell us when the ground station that picked up the radio transmission received it. But in cases where messages are relayed as part of a large-scale network that collects AIS data from numerous stations, it might just tell you when the particular equipment you're plugged into received the message.

So for that reason I'm not sure if it is really correct to attach this to the types that represent AIS messages.

If you need access to information from the NMEA layer, might it be better to design in something where we make that available, and make it clear which pieces of information came from where?

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Again my scope to refactor and improve general code quality is limited as I have many other commitments but would welcome PRs on my repository if you dont want to undertake this work in yours.

{
var parser = new NmeaAisPositionReportClassAParser(asciiPayload, padding);

Expand All @@ -108,12 +114,13 @@ private void ParseMessageTypes1Through3(ReadOnlySpan<byte> asciiPayload, uint pa
SpareBits145: parser.SpareBits145,
SpeedOverGround: parser.SpeedOverGroundTenths.FromTenths(),
TimeStampSecond: parser.TimeStampSecond,
TrueHeadingDegrees: parser.TrueHeadingDegrees);
TrueHeadingDegrees: parser.TrueHeadingDegrees,
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
}

private void ParseMessageType5(ReadOnlySpan<byte> asciiPayload, uint padding)
private void ParseMessageType5(NmeaLineParser nmeaLineParser, ReadOnlySpan<byte> asciiPayload, uint padding)
{
var parser = new NmeaAisStaticAndVoyageRelatedDataParser(asciiPayload, padding);

Expand All @@ -137,12 +144,13 @@ private void ParseMessageType5(ReadOnlySpan<byte> asciiPayload, uint padding)
DimensionToStern: parser.DimensionToStern,
Draught10thMetres: parser.Draught10thMetres,
Spare423: parser.Spare423,
PositionFixType: parser.PositionFixType);
PositionFixType: parser.PositionFixType,
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
}

private void ParseMessageType18(ReadOnlySpan<byte> asciiPayload, uint padding)
private void ParseMessageType18(NmeaLineParser nmeaLineParser, ReadOnlySpan<byte> asciiPayload, uint padding)
{
var parser = new NmeaAisPositionReportClassBParser(asciiPayload, padding);

Expand All @@ -164,12 +172,13 @@ private void ParseMessageType18(ReadOnlySpan<byte> asciiPayload, uint padding)
TrueHeadingDegrees: parser.TrueHeadingDegrees,
IsAssigned: parser.IsAssigned,
RaimFlag: parser.RaimFlag,
RepeatIndicator: parser.RepeatIndicator);
RepeatIndicator: parser.RepeatIndicator,
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
}

private void ParseMessageType19(ReadOnlySpan<byte> asciiPayload, uint padding)
private void ParseMessageType19(NmeaLineParser nmeaLineParser, ReadOnlySpan<byte> asciiPayload, uint padding)
{
var parser = new NmeaAisPositionReportExtendedClassBParser(asciiPayload, padding);

Expand Down Expand Up @@ -197,12 +206,13 @@ private void ParseMessageType19(ReadOnlySpan<byte> asciiPayload, uint padding)
SpeedOverGround: parser.SpeedOverGroundTenths.FromTenths(),
TimeStampSecond: parser.TimeStampSecond,
TrueHeadingDegrees: parser.TrueHeadingDegrees,
Position: Position.From10000thMins(parser.Latitude10000thMins, parser.Longitude10000thMins));
Position: Position.From10000thMins(parser.Latitude10000thMins, parser.Longitude10000thMins),
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
}

private void ParseMessageType24(ReadOnlySpan<byte> asciiPayload, uint padding)
private void ParseMessageType24(NmeaLineParser nmeaLineParser, ReadOnlySpan<byte> asciiPayload, uint padding)
{
uint part = NmeaAisStaticDataReportParser.GetPartNumber(asciiPayload, padding);

Expand All @@ -219,7 +229,8 @@ private void ParseMessageType24(ReadOnlySpan<byte> asciiPayload, uint padding)
Mmsi: parser.Mmsi,
PartNumber: parser.PartNumber,
RepeatIndicator: parser.RepeatIndicator,
Spare160: parser.Spare160);
Spare160: parser.Spare160,
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
break;
Expand Down Expand Up @@ -253,12 +264,32 @@ private void ParseMessageType24(ReadOnlySpan<byte> asciiPayload, uint padding)
Spare162: parser.Spare162,
UnitModelCode: parser.UnitModelCode,
VendorIdRev3: vendorIdRev3Ascii.GetString(),
VendorIdRev4: vendorIdRev4Ascii.GetString());
VendorIdRev4: vendorIdRev4Ascii.GetString(),
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
break;
}
}
}

private void ParseMessageType27(NmeaLineParser nmeaLineParser, ReadOnlySpan<byte> asciiPayload, uint padding)
{
var parser = new NmeaAisLongRangeAisBroadcastParser(asciiPayload, padding);

var message = new AisMessageType27(
Mmsi: parser.Mmsi,
Position: Position.From10thMins(parser.Latitude10thMins, parser.Longitude10thMins),
CourseOverGroundDegrees: parser.CourseOverGroundDegrees,
PositionAccuracy: parser.PositionAccuracy,
SpeedOverGround: parser.SpeedOverGroundTenths.FromTenths(),
RaimFlag: parser.RaimFlag,
RepeatIndicator: parser.RepeatIndicator,
NotGnssPosition: parser.NotGnssPosition,
NavigationStatus: parser.NavigationStatus,
UnixTimestamp: nmeaLineParser.TagBlock.UnixTimestamp);

this.messages.OnNext(message);
}
}
}