Diff: CMD_Interpreter.cpp

Revision:

1:6f5b84940d04

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CMD_Interpreter.cpp	Fri Jun 21 15:26:49 2019 +0000
@@ -0,0 +1,200 @@
+// *****************************************************************
+// Handle all the LEDs with some general function wrappers functions
+// *****************************************************************
+#include "CMD_Interpreter.h"
+
+//************************************
+// Interpreter Class Creation 
+//************************************
+// Strategy: the interpreter accumulates characters in its input buffer
+// it flags the presence of complete lines
+// it also flags Overflow of the buffer in which case all subsequent characters 
+//       are lost until the queue is emptied, and a CR-LF is received
+// Defined States of the interpreter: 
+//     MyState = isStartNew, isLineFilling, isOverflow, isWaitNewLine};
+
+// #define DEBUG(...) { snprintf(buff, sizeof(buff), __VA_ARGS__);   DataLog( buff );  }
+
+Interpreter::Interpreter( void ) 
+{ Reinit( );
+  MyState = isStartNew;
+  AllCommands = NULL;
+  NumCommands = 0;
+}
+
+void Interpreter::FillCommands( int aNumCommands, const  EXE_CMD_TYPE *ACommands  )
+{   int cnt;
+    AllCommands = new EXE_CMD_TYPE[ aNumCommands ];
+    for( cnt=0; cnt<aNumCommands; cnt++)
+      { AllCommands[cnt] = ACommands[cnt]; } ;
+    NumCommands = aNumCommands;
+}
+
+void Interpreter::Reinit( void ) {
+    MyState = isWaitNewLine; // indicates no buffer overflow
+    WriteIndex = 0;  // points to next index to write to
+    LinesComplete = 0; // indicates that no complete line is currently available 
+    // Start Scanning at the start
+    ScanIndex = 0;
+    BufAvail = BuffLen;// the full buffer size is available 
+ }
+
+// Barebone function, assumes that checks havee been performed by writeBuf!
+void Interpreter::AddChar( char aChar ) {
+    if (aChar == 8) // is it a backspace code, then remove one character:
+      { if (BufAvail<BuffLen) { // there's actually a character to be removed
+            BufAvail++; // Buffer regrows
+            if (WriteIndex == 0) {WriteIndex=BuffLen-1;}
+               else {WriteIndex--;} // recoil the write index
+          }
+      }
+    else {
+        if (WriteIndex == BuffLen-1) {WriteIndex=0;}
+           else {WriteIndex++;}
+        RingBuf[WriteIndex]=aChar; // all right, buffer it!
+        BufAvail--; // Buffer is shrinking
+        if (BufAvail==0) { MyState = isOverflow; }
+     }
+}                 
+
+// High level method to add a Char to the buffer,
+// Separates at Chars 10, 13, 0; replaced by a single 0 char
+// Blocking write when buffer has overflowed
+void Interpreter::writeBuf(char aChar) {
+  bool LineEnds = aChar==10 || aChar==13 || aChar==0;
+  switch (MyState) {
+    case isOverflow: break;
+    case isStartNew:  // ready for the next line to start
+        // avoid that consecutive CR LF are counted as multiple lines 
+        if (!LineEnds) {AddChar(aChar ); MyState = isLineFilling; } 
+        break;
+    case isLineFilling:// New line has started filling
+        if (!LineEnds)  {AddChar(aChar);} 
+          else 
+            {MyState = isStartNew; // ready for the next line
+             // Between consecutive commands, the endstring=NULL character is inserted
+             // this is to indicate that line was already counted as completed
+             AddChar(0 ); // append a line end char, will detect bufferFull!
+             LinesComplete++; } // count completed lines        
+        break;
+    case isWaitNewLine: // waiting for a new line end to arrive after an overflow
+        if (LineEnds) { MyState = isStartNew; }
+        break;
+    default: MyState = isOverflow; // goes into error state, should never happen though
+    }   
+} // writeBuf
+
+// Barebone function, that performs the checks to be performed!
+// Passes back the actC, and reads already the nextChar into actC
+char Interpreter::GetAChar( void ) {
+char oldC = actC;
+    if (BufAvail==BuffLen) { actC = 0; LinesComplete=0; } // buffer is empty, no more lines!!
+    else // something is in the buffer 
+      { if (ScanIndex == BuffLen) {ScanIndex=0;}
+           else {ScanIndex++;}
+        actC=RingBuf[ScanIndex]; // all right, get it
+        if (actC==0) {LinesComplete--; } // now there is one line less in the storage
+        BufAvail++; // Buffer is increasing
+      } // something is in the buffer 
+    return oldC;
+}                 
+
+// skip true blank, but also Tab characters
+void Interpreter::SkipBlanks( void ) {
+    while(BufAvail<BuffLen && (actC==' ' || actC==9|| actC==0)) { GetAChar(); }
+} // SkipBlanks
+
+int Interpreter::ReadAnInt( void ) {
+bool Negative = false;
+int  Result = 0;
+    if (actC=='-') {Negative = true; GetAChar(); }
+    else if (actC=='+') {Negative = false; GetAChar(); }
+    while(BufAvail<BuffLen  && actC>='0' && actC<='9') 
+        { Result = Result * 10 + (GetAChar()-'0') ; }
+    return Negative? -Result : Result;
+} // ReadAnInt
+
+
+RD_CMD_TYPE Interpreter::ParseCommand( void ) {
+  RD_CMD_TYPE cmd; // locally built command
+    actC=RingBuf[ScanIndex]; // initialiye the actC variable, as the first char to use
+    SkipBlanks();
+    // Next Character is the command
+    cmd.Command = GetAChar();
+    // Next Blanks are to be omitted, but are not even mandatory
+    SkipBlanks();
+    if ((actC>='0' && actC<='9') || actC=='-' || actC=='+' )
+           { cmd.Parameter= ReadAnInt(); cmd.NumParam = 1; }
+      else { cmd.Parameter= 0;           cmd.NumParam = 0; }
+    SkipBlanks( ); // There should be at least a trailing NUL character to be removed
+    return cmd; // return the built command
+}
+
+bool Interpreter::executeCommand(RD_CMD_TYPE cmd) {
+    int CmdNr;
+    bool Found;
+    CmdNr = 0;
+    Found = false; 
+    // DEBUG("Com '%c'=%d %d NPar=%d \n\r",cmd.Command, cmd.Command, cmd.Parameter, cmd.NumParam);
+    // While not found go through all the commands, linear; they are not sorted by alphabet.
+    while(CmdNr<NumCommands && !Found) 
+      { // DEBUG("NR:%d \n\r", CmdNr);
+        if (AllCommands[CmdNr].cmd == cmd.Command) 
+            { // the command character matches
+              if (cmd.NumParam == AllCommands[CmdNr].Npar) 
+                  { // DEBUG("Execute: %s \n\r", AllCommands[CmdNr].help);
+                    AllCommands[CmdNr].Handler( cmd.Parameter ); // then call the handler 
+                  }
+               //  else { DataLog("Param Mismatch!\n\r");  } // Inform about Parameter error
+            Found = true; // and mark as found 
+            }
+        else { CmdNr++; } // go on serarching
+      } // while   
+    // if ( !Found )  { CmdInval(cmd.Command) ;  } // call invalid command function
+    return Found;
+}
+
+bool Interpreter::ProcessPresentCommands( void )
+{   RD_CMD_TYPE Readcmd;
+    if (MyState==isOverflow)   { Reinit(); } 
+    if(LinesComplete>0) 
+       { // DEBUG("X: Scan=%d ", Interp.ScanIndex); 
+         Readcmd = ParseCommand();
+         executeCommand( Readcmd ); 
+         //DEBUG("state=%d; wix=%d; rix=%d; buf=%s ", Interp.MyState, Interp.WriteIndex, Interp.ScanIndex, &Interp.RingBuf[Interp.ScanIndex]); 
+         return true;
+        } 
+      else { return false; }
+}
+
+char *ParamHelp[] = {"     ", "<param>", "<par><par>"};
+
+void Interpreter::PrtCmdHelp  (Serial *aSerial ) // Display list of Commands
+{   EXE_CMD_TYPE *com;
+    int CmdNr;
+    char *parStr;
+    // DataLog("List of commands: \n\r"); 
+    // Go Through all commands in the table
+    for (CmdNr = 0; CmdNr<NumCommands; CmdNr++ )
+      { com = &AllCommands[CmdNr]; // get a pointer to the command
+        parStr = ParamHelp[com->Npar]; // Get the string that represents the number of parameters
+        aSerial->printf( " %c %s => %s \n\r", com->cmd, parStr, com->help.c_str() );  // output the full command help
+      }   
+}
+
+/*
+void Interpreter::CmdInval( int param ) // Feedback that the command is invalid
+{ DEBUG( " Invalid command %d = '%c'; use: 'h' for help. \n\r",  param, char(param) ) ; 
+}
+
+string Interpreter::GetLastMessage( void )
+{ string LastMsg = LastMessage;
+  LastMessage = ""; // Empty the old Message
+  return LastMsg;
+}
+
+void Interpreter::DataLog( char *DebugMessage )
+{ if (LastMessage=="" ) { LastMessage = DebugMessage; }
+    else { LastMessage = LastMessage + "\n\r" + DebugMessage; }
+};
+*/