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Improved file reader to read lines in message groups to better simulate an NMEA device

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mort5161 2015-03-20 16:20:02 -07:00
parent 376014e385
commit 6fcd2ebca4
3 changed files with 51 additions and 23 deletions
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54
src/NmeaParser.Shared/BufferedStreamDevice.cs
View file

@ -34,13 +34,13 @@ namespace NmeaParser
/// <summary>
/// Initializes a new instance of the <see cref="BufferedStreamDevice"/> class.
/// </summary>
protected BufferedStreamDevice() : this(200)
protected BufferedStreamDevice() : this(1000)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="BufferedStreamDevice"/> class.
/// </summary>
/// <param name="readSpeed">The time to wait between each line being read in milliseconds</param>
/// <param name="readSpeed">The time to wait between each group of lines being read in milliseconds</param>
protected BufferedStreamDevice(int readSpeed)
{
m_readSpeed = readSpeed;
@ -77,30 +77,50 @@ namespace NmeaParser
}
// stream that slowly populates a buffer from a StreamReader to simulate nmea messages coming
// in line by line at a steady stream
// in lastLineRead by lastLineRead at a steady stream
private class BufferedStream : Stream
{
StreamReader m_sr;
byte[] m_buffer = new byte[0];
System.Threading.Timer m_timer;
object lockObj = new object();
private StreamReader m_sr;
private byte[] m_buffer = new byte[0];
private System.Threading.Timer m_timer;
private object lockObj = new object();
private string groupToken = null;
private string lastLineRead = null;
/// <summary>
/// Initializes a new instance of the <see cref="BufferedStream"/> class.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="readSpeed">The read speed.</param>
/// <param name="readSpeed">The read speed in milliseconds.</param>
public BufferedStream(StreamReader stream, int readSpeed)
{
m_sr = stream;
m_timer = new System.Threading.Timer(OnRead, null, 0, readSpeed); //add a new line to buffer every 100 ms
m_timer = new System.Threading.Timer(OnRead, null, 0, readSpeed); //read a group of lines every 'readSpeed' milliseconds
}
private void OnRead(object state)
{
if (m_sr.EndOfStream)
m_sr.BaseStream.Seek(0, SeekOrigin.Begin); //start over
//populate the buffer with a line
string line = m_sr.ReadLine() + '\n';
if (lastLineRead != null)
AppendToBuffer(lastLineRead);
//Get the group token if we don't have one
while (groupToken == null && (lastLineRead == null || !lastLineRead.StartsWith("$", StringComparison.Ordinal)))
{
lastLineRead = ReadLine(); //seek forward to first nmea token
AppendToBuffer(lastLineRead);
}
if(groupToken == null)
{
var values = lastLineRead.Trim().Split(new char[] { ',' });
if (values.Length > 0)
groupToken = values[0];
}
lastLineRead = ReadLine();
while (!lastLineRead.StartsWith(groupToken, StringComparison.Ordinal)) //keep reading until messages start repeating again
{
AppendToBuffer(lastLineRead);
lastLineRead = ReadLine();
}
}
private void AppendToBuffer(string line)
{
var bytes = Encoding.UTF8.GetBytes(line);
lock (lockObj)
{
@ -110,6 +130,12 @@ namespace NmeaParser
m_buffer = newBuffer;
}
}
private string ReadLine()
{
if (m_sr.EndOfStream)
m_sr.BaseStream.Seek(0, SeekOrigin.Begin); //start over
return m_sr.ReadLine() + '\n';
}
/// <summary>
/// Gets a value indicating whether this instance can read.
/// </summary>

13
src/NmeaParser.Shared/NmeaDevice.cs
View file

@ -81,7 +81,7 @@ namespace NmeaParser
{
OnData(buffer.Take(readCount).ToArray());
}
await Task.Delay(10, token);
await Task.Delay(50, token);
}
if (closeTask != null)
closeTask.SetResult(true);
@ -123,19 +123,22 @@ namespace NmeaParser
private void OnData(byte[] data)
{
var nmea = System.Text.Encoding.UTF8.GetString(data, 0, data.Length);
string line = null;
List<string> lines = new List<string>();
lock (m_lockObject)
{
m_message += nmea;
var lineEnd = m_message.IndexOf("\n", StringComparison.Ordinal);
if (lineEnd > -1)
while (lineEnd > -1)
{
line = m_message.Substring(0, lineEnd).Trim();
string line = m_message.Substring(0, lineEnd).Trim();
m_message = m_message.Substring(lineEnd + 1);
if (!string.IsNullOrEmpty(line))
lines.Add(line);
lineEnd = m_message.IndexOf("\n", StringComparison.Ordinal);
}
}
if (!string.IsNullOrEmpty(line))
foreach(var line in lines)
ProcessMessage(line);
}

7
src/NmeaParser.Shared/NmeaFileDevice.cs
View file

@ -39,9 +39,9 @@ namespace NmeaParser
/// </summary>
/// <param name="fileName"></param>
#if NETFX_CORE
public NmeaFileDevice(Windows.Storage.IStorageFile fileName) : this(fileName, 200)
public NmeaFileDevice(Windows.Storage.IStorageFile fileName) : this(fileName, 1000)
#else
public NmeaFileDevice(string fileName) : this(fileName, 200)
public NmeaFileDevice(string fileName) : this(fileName, 1000)
#endif
{
m_filename = fileName;
@ -50,7 +50,7 @@ namespace NmeaParser
/// Initializes a new instance of the <see cref="NmeaFileDevice"/> class.
/// </summary>
/// <param name="fileName"></param>
/// <param name="readSpeed">The time to wait between each line being read in milliseconds</param>
/// <param name="readSpeed">The time to wait between each group of lines being read in milliseconds</param>
#if NETFX_CORE
public NmeaFileDevice(Windows.Storage.IStorageFile fileName, int readSpeed)
: base(readSpeed)
@ -62,7 +62,6 @@ namespace NmeaParser
}
#if !NETFX_CORE
/// <summary>
/// Gets the name of the nmea file this device is using.
/// </summary>