Merge pull request #44 from lawson89/main

Fix bug in temp calc

Author: gcarreno

entries/rlawson/src/parser.pas

@@ -5,7 +5,7 @@
 interface
 
 uses
-  Classes, SysUtils, bufstream, Contnrs, Math;
+  Classes, SysUtils, bufstream, Contnrs, Math, util;
 
 procedure ReadMeasurements(inputFile: string);
 
@@ -44,12 +44,12 @@ procedure ProcessMeasurements(var buffer: array of char; bufferLength: integer;
 begin
   while idx < (bufferLength - 1) do
   begin
-    // read the city until separator
-    //city := '';
+    // read the city by looking for semicolon
+    city := '';
     cityStart := idx;
     while buffer[idx] <> REC_SEP do Inc(idx);
     SetString(city, @buffer[cityStart], (idx - cityStart));
-    // increment through temp reading and calculate integer temp (*100)
+    // parse the temp reading
     Inc(idx); // move pointer past the ;
     currentTempSign := 1;
     // check for negative sign, if so flag the multiplier and then move past neg sign
@@ -59,20 +59,16 @@ procedure ProcessMeasurements(var buffer: array of char; bufferLength: integer;
       Inc(idx);
     end;
     // look ahead - is decimal point 2 spaces away then we have two digits
+    temp := 0;
     if buffer[idx + 2] = DECIMAL_POINT then
     begin
-      temp := currentTempSign * (100 * byte(buffer[idx]) + 10 *
-        byte(buffer[idx + 1]) + byte(buffer[idx + 2]) - 5328);
-      // move past digits and CRLF and position pointer to first character of next record
-      idx := idx + 6;
-    end
-    else
-    begin
-      temp := currentTempSign * (10 * byte(buffer[idx + 1]) +
-        byte(buffer[idx + 2]) - 528);
-      // move past digits and CRLF and position pointer to first character of next record
-      idx := idx + 5;
+      temp := 100 * (byte(buffer[idx]) - ANSI_ZERO);
+      Inc(idx);
     end;
+    temp := temp + 10 * (byte(buffer[idx]) - ANSI_ZERO);
+    idx := idx + 2;
+    temp := currentTempSign * (temp + (byte(buffer[idx]) - ANSI_ZERO));
+    idx := idx + 3;
     reading := results.Find(city);
     if reading = nil then
     begin
@@ -94,51 +90,6 @@ procedure ProcessMeasurements(var buffer: array of char; bufferLength: integer;
   end;
 end;
 
-function PascalRound(x: double): double;
-var
-  t: double;
-begin
-  //round towards positive infinity
-  t := Trunc(x);
-  if (x < 0.0) and (t - x = 0.5) then
-  begin
-    // Do nothing
-  end
-  else if Abs(x - t) >= 0.5 then
-  begin
-    t := t + Math.Sign(x);
-  end;
-
-  if t = 0.0 then
-    Result := 0.0
-  else
-    Result := t;
-end;
-
-
-function RoundEx(x: double): double;
-begin
-  Result := PascalRound(x * 10.0) / 10.0;
-end;
-
-function Compare(AList: TStringList; AIndex1, AIndex2: integer): integer;
-var
-  Pos1, Pos2: integer;
-  Str1, Str2: string;
-begin
-  Result := 0;
-  Str1 := AList.Strings[AIndex1];
-  Str2 := AList.Strings[AIndex2];
-  Pos1 := Pos('=', Str1);
-  Pos2 := Pos('=', Str2);
-  if (Pos1 > 0) and (Pos2 > 0) then
-  begin
-    Str1 := Copy(Str1, 1, Pos1 - 1);
-    Str2 := Copy(Str2, 1, Pos2 - 1);
-    Result := CompareStr(Str1, Str2);
-  end;
-end;
-
 procedure DumpMeasurements(results: TFPHashList);
 var
   i: integer;
@@ -160,11 +111,6 @@ procedure DumpMeasurements(results: TFPHashList);
     mean := RoundEx(reading^.total / reading^.numReadings / 10);
     readingStr := reading^.city + '=' + FormatFloat('0.0', min) +
       '/' + FormatFloat('0.0', mean) + '/' + FormatFloat('0.0', max);
-    {$IFDEF DEBUG}
-       readingStr := reading^.city + '=' + FormatFloat('0.0', min) +
-      '/' + FormatFloat('0.0', mean) + '/' + FormatFloat('0.0', max) +
-      '/' + IntToStr(reading^.total) + '/' + IntToStr(reading^.numReadings);
-    {$ENDIF}
     weatherStationList.Add(readingStr);
     Dispose(reading);
   end;
@@ -183,40 +129,14 @@ procedure DumpMeasurements(results: TFPHashList);
   WriteLn('}');
 end;
 
-
-procedure DumpExceptionCallStack(E: Exception);
-var
-  I: integer;
-  Frames: PPointer;
-  Report: string;
-begin
-  Report := 'Program exception! ' + LineEnding + 'Stacktrace:' +
-    LineEnding + LineEnding;
-  if E <> nil then
-  begin
-    Report := Report + 'Exception class: ' + E.ClassName + LineEnding +
-      'Message: ' + E.Message + LineEnding;
-  end;
-  Report := Report + BackTraceStrFunc(ExceptAddr);
-  Frames := ExceptFrames;
-  for I := 0 to ExceptFrameCount - 1 do
-    Report := Report + LineEnding + BackTraceStrFunc(Frames[I]);
-  WriteLn(Report);
-  Halt; // End of program execution
-end;
-
-
 procedure ReadMeasurements(inputFile: string);
 var
   totalBytesRead, BytesRead: int64;
   Buffer: array [0..BUFFER_SIZE] of char;
   FileStream: TFileStream;
   fileSize: int64;
   ReadBufferStream: TReadBufStream;
-  starttime: uint64;
-  elapsedTimeSec, MBRead: double;
   results: TFPHashList;
-  currentChar: char;
   idx: integer;
   startOfNextRecord: string;
   startOfNextRecordLength: integer;
@@ -228,50 +148,29 @@ procedure ReadMeasurements(inputFile: string);
     ReadBufferStream := TReadBufStream.Create(FileStream);
     fileSize := FileStream.size;
     totalBytesRead := 0;
-    starttime := GetTickCount64;
     results := TFPHashList.Create;
     startOfNextRecord := '';
     while totalBytesRead <= fileSize do
       // While the amount of data read is less than or equal to the size of the stream do
     begin
       startOfNextRecordLength := Length(startOfNextRecord);
-      //WriteLn('startOfNextRecordLength: ', startOfNextRecordLength);
       // if we have leftover from previous read then prepend it to this buffer
       if startOfNextRecordLength > 0 then
         Move(PChar(startOfNextRecord)^, Buffer[0], startOfNextRecordLength);
       BytesRead := ReadBufferStream.Read(Buffer[startOfNextRecordLength], READ_SIZE);
-      //WriteLn('Bytes read: ', BytesRead);
       if BytesRead < 1 then break;
       // now look in buffer backwards until we find the first LF
       bufferLength := startOfNextRecordLength + BytesRead;
       idx := bufferLength - 1;
-      currentChar := buffer[idx];
-      while (currentChar <> LF) do
-      begin
-        Dec(idx);
-        currentChar := buffer[idx];
-      end;
+      while (buffer[idx] <> LF) do Dec(idx);
       ProcessMeasurements(Buffer, idx + 1, results);
       startOfNextRecord := '';
       startOfNextRecordLength := bufferLength - idx - 1;
-      //WriteLn('startOfNextRecordLength: ', startOfNextRecordLength);
       if startOfNextRecordLength > 0 then
         SetString(startOfNextRecord, @buffer[idx + 1], startOfNextRecordLength);
       Inc(totalBytesRead, BytesRead);
     end;
     DumpMeasurements(results);
-    elapsedTimeSec := (GetTickCount64() - starttime) / 1000;
-    MBRead := (totalBytesRead / (1024 * 1024));
-    {$IFDEF DEBUG}
-    WriteLn(inputFile);
-    WriteLn('Buffer size: ', SizeOf(Buffer));
-    WriteLn('Read size: ', READ_SIZE);
-    WriteLn('File size: ', FileStream.Size);
-    WriteLn('Total Bytes Read: ', totalBytesRead);
-    WriteLn(Format('%f MB read', [MBRead]));
-    WriteLn(Format('%f secs', [elapsedTimeSec]));
-    WriteLn(Format('%f MB/s processed', [MBRead / elapsedTimeSec]));
-    {$ENDIF}
     ReadBufferStream.Free;
     FileStream.Free;
     results.Free;

entries/rlawson/src/util.pas

@@ -0,0 +1,82 @@
+unit util;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Math;
+
+procedure DumpExceptionCallStack(E: Exception);
+function RoundEx(x: double): double;
+function Compare(AList: TStringList; AIndex1, AIndex2: integer): integer;
+
+implementation
+
+procedure DumpExceptionCallStack(E: Exception);
+var
+  I: integer;
+  Frames: PPointer;
+  Report: string;
+begin
+  Report := 'Program exception! ' + LineEnding + 'Stacktrace:' +
+    LineEnding + LineEnding;
+  if E <> nil then
+  begin
+    Report := Report + 'Exception class: ' + E.ClassName + LineEnding +
+      'Message: ' + E.Message + LineEnding;
+  end;
+  Report := Report + BackTraceStrFunc(ExceptAddr);
+  Frames := ExceptFrames;
+  for I := 0 to ExceptFrameCount - 1 do
+    Report := Report + LineEnding + BackTraceStrFunc(Frames[I]);
+  WriteLn(Report);
+  Halt; // End of program execution
+end;
+
+function PascalRound(x: double): double;
+var
+  t: double;
+begin
+  //round towards positive infinity
+  t := Trunc(x);
+  if (x < 0.0) and (t - x = 0.5) then
+  begin
+    // Do nothing
+  end
+  else if Abs(x - t) >= 0.5 then
+  begin
+    t := t + Math.Sign(x);
+  end;
+
+  if t = 0.0 then
+    Result := 0.0
+  else
+    Result := t;
+end;
+
+
+function RoundEx(x: double): double;
+begin
+  Result := PascalRound(x * 10.0) / 10.0;
+end;
+
+function Compare(AList: TStringList; AIndex1, AIndex2: integer): integer;
+var
+  Pos1, Pos2: integer;
+  Str1, Str2: string;
+begin
+  Result := 0;
+  Str1 := AList.Strings[AIndex1];
+  Str2 := AList.Strings[AIndex2];
+  Pos1 := Pos('=', Str1);
+  Pos2 := Pos('=', Str2);
+  if (Pos1 > 0) and (Pos2 > 0) then
+  begin
+    Str1 := Copy(Str1, 1, Pos1 - 1);
+    Str2 := Copy(Str2, 1, Pos2 - 1);
+    Result := CompareStr(Str1, Str2);
+  end;
+end;
+
+end.

entries/rlawson/src/weather.lpi

@@ -83,7 +83,7 @@
     <RunParams>
       <FormatVersion Value="2"/>
     </RunParams>
-    <Units Count="2">
+    <Units Count="3">
       <Unit0>
         <Filename Value="weather.lpr"/>
         <IsPartOfProject Value="True"/>
@@ -92,6 +92,10 @@
         <Filename Value="parser.pas"/>
         <IsPartOfProject Value="True"/>
       </Unit1>
+      <Unit2>
+        <Filename Value="util.pas"/>
+        <IsPartOfProject Value="True"/>
+      </Unit2>
     </Units>
   </ProjectOptions>
   <CompilerOptions>

entries/rlawson/src/weather.lpr

@@ -4,11 +4,12 @@
 
 uses
   {$IFDEF UNIX}
-  cthreads,
+  cmem, cthreads,
   {$ENDIF}
   Classes,
   SysUtils,
-  CustApp, parser;
+  CustApp,
+  parser;
 
 type