#include <stdio.h>

#ifndef BYTE

#define BYTE unsigned char

#define WORD unsigned short

#define DWORD unsigned long

#define BOOL BYTE

#define TRUE 1

#define FALSE 0

#endif

#include "bag.h"

#define MAX_POOL 512

static BYTE Pool[MAX_POOL];

static int PoolSize=MAX_POOL-5; //Could be 512, but to reduce possibility of various

//off-by errors that could crash the system, make it less.

//You don't have to do this, but I like margins of safety.

static BYTE* pWorkingPool;

static int WorkingPoolSize;

BOOL BAG_ClearAll(void)

{

int j;

for (j=0;j<WorkingPoolSize;j++) pWorkingPool[j]=BAG_EOL;

return(TRUE);

}

BOOL BAG_Init()

{

pWorkingPool=&Pool[0];

WorkingPoolSize=PoolSize;

BAG_ClearAll(); //Start with an empty bag.

printf("TODO: Read bag structure from nonvolatile storage...\r\n");

//TODO: Read the bag structure from a disk file, flash, or battery backed RAM.

return(TRUE);

}

BOOL BAG_Save(void)

{

printf("TODO: Save bag to nonvolatile storage...\r\n");

//TODO: Write the bag structure to a disk file, flash, or battery backed RAM.

return(TRUE);

}

BOOL BAG_DelTag(BYTE Tag)

{

int Index1,Index2;

BYTE k,j;

BYTE TempPool[MAX_POOL];

int r;

Index1=0;

Index2=0;

for (r=0;r<sizeof(TempPool);r++) TempPool[r]=BAG_EOL;

while (1)

{

if (pWorkingPool[Index1]==BAG_EOL)

{

for (r=0;r<WorkingPoolSize;r++) pWorkingPool[r]=TempPool[r];

return(TRUE);

}

if (pWorkingPool[Index1]==Tag)

{

Index1++;

k=pWorkingPool[Index1];

Index1+=k;

Index1++;

}

else

{

TempPool[Index2]=pWorkingPool[Index1];

Index1++;

Index2++;

k=pWorkingPool[Index1];

TempPool[Index2]=k;

Index1++;

Index2++;

for (j=0;j<k;j++) TempPool[Index2+j]=pWorkingPool[Index1+j];

Index1+=k;

Index2+=k;

}

}

return(TRUE);

}

BOOL BAG_PutTag(BYTE Tag,void* Buf,BYTE Len)

{

int Index;

BYTE k,j;

BYTE* pByte;

//Erase the existing value, if present.

BAG_DelTag(Tag);

//Now save the new value.

pByte=(BYTE*)Buf;

Index=0;

while (1)

{

if (pWorkingPool[Index]==BAG_EOL)

{

pWorkingPool[Index]=Tag;

Index++;

pWorkingPool[Index]=Len;

Index++;

for (j=0;j<Len;j++) pWorkingPool[Index+j]=pByte[j];

return(TRUE);

}

else

{

Index++; //Increment to data length

k=pWorkingPool[Index]; //Get it.

Index+=k; //Increment over data portion

Index++; //Point to next tag

}

}

return(TRUE);

}

BOOL BAG_GetTag(BYTE Tag,void* Buf,BYTE BufLen)

{

int Index;

BYTE k,j;

BYTE* pByte;

pByte=(BYTE*)Buf;

Index=0;

while (1)

{

if (pWorkingPool[Index]==BAG_EOL) return(FALSE);

if (pWorkingPool[Index]==Tag)

{

Index++;

k=pWorkingPool[Index];

Index++;

for (j=0;j<k;j++)

{

if (j<BufLen) pByte[j]=pWorkingPool[Index+j];

}

return(TRUE);

}

else

{

Index++;

k=pWorkingPool[Index];

Index+=k;

Index++;

}

}

return(TRUE);

}