btestvlr.cpp

This is an example of variable length records based on btest.cpp .

#ifndef __GNUC__
        #define _CRT_SECURE_NO_WARNINGS
#endif

#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "btrieveCpp.h"

#ifndef __GNUC__
        #define snprintf _snprintf
#endif

static char *btrieveFileName = (char *)"squaresAndSquareRoots.btr";

#define MIN_X 0
#define MAX_X 255
#define RECORD_FIXED_SIZE 11
#define RECORD_MAXIMUM_VARIABLE_SIZE 1024
#define RECORD_MAXIMUM_TOTAL_SIZE (RECORD_FIXED_SIZE + RECORD_MAXIMUM_VARIABLE_SIZE)

#pragma pack(1)
typedef struct {
        struct 
        {
                uint8_t x;
                uint16_t xSquared;
                double xSquareRoot;
        } fixed;
        char text[RECORD_MAXIMUM_VARIABLE_SIZE];
} record_t;
#pragma pack()

static Btrieve::StatusCode
createFile(BtrieveClient *btrieveClient)
{
   Btrieve::StatusCode status;
   BtrieveFileAttributes btrieveFileAttributes;

   // If SetFixedRecordLength() fails.
   if ((status = btrieveFileAttributes.SetFixedRecordLength(RECORD_FIXED_SIZE)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveFileAttributes::SetFixedRecordLength():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

   // If SetVariableLengthRecordsMode() fails.
   if ((status = btrieveFileAttributes.SetVariableLengthRecordsMode(Btrieve::VARIABLE_LENGTH_RECORDS_MODE_YES)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveFileAttributes::SetVariableLengthRecordsMode():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

   // If FileCreate() fails.
   if ((status = btrieveClient->FileCreate(&btrieveFileAttributes, btrieveFileName, Btrieve::CREATE_MODE_OVERWRITE)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveClient::FileCreate():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

leave:
   return status;
}

static Btrieve::StatusCode
openFile(BtrieveClient *btrieveClient, BtrieveFile *btrieveFile)
{
   Btrieve::StatusCode status;

   // If FileOpen() fails.
   if ((status = btrieveClient->FileOpen(btrieveFile, btrieveFileName, NULL, Btrieve::OPEN_MODE_NORMAL)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveClient::FileOpen():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

leave:
   return status;
}

static Btrieve::StatusCode
loadFile(BtrieveFile *btrieveFile)
{
   Btrieve::StatusCode status = Btrieve::STATUS_CODE_NO_ERROR;
   int i;
   record_t record;

   for (i = MIN_X; i <= MAX_X; i++)
   {
      record.fixed.x = (uint8_t)i;
      record.fixed.xSquared = (uint16_t)(i * i);
      record.fixed.xSquareRoot = sqrt((double)i);
      snprintf(record.text, RECORD_MAXIMUM_VARIABLE_SIZE, "The square of %d is %d and its square root is %f.", record.fixed.x, record.fixed.xSquared, record.fixed.xSquareRoot);
      record.text[RECORD_MAXIMUM_VARIABLE_SIZE - 1] = '\0';

      // If RecordCreate() fails.
      if ((status = btrieveFile->RecordCreate((char *)&record, RECORD_FIXED_SIZE + (int)strlen(record.text) + 1)) != Btrieve::STATUS_CODE_NO_ERROR)
      {
         printf("Error: BtrieveFile::RecordCreate():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
         goto leave;
      }
   }

leave:
   return status;
}

static Btrieve::StatusCode
closeFile(BtrieveClient *btrieveClient, BtrieveFile *btrieveFile)
{
   Btrieve::StatusCode status;

   // If FileClose() fails.
   if ((status = btrieveClient->FileClose(btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveClient::FileClose():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

leave:
   return status;
}

static Btrieve::StatusCode
deleteFile(BtrieveClient *btrieveClient)
{
   Btrieve::StatusCode status;

   // If FileDelete() fails.
   if ((status = btrieveClient->FileDelete(btrieveFileName)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveClient::FileDelete():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

leave:
   return status;
}

static Btrieve::StatusCode
createIndex(BtrieveFile *btrieveFile)
{
   Btrieve::StatusCode status;
   BtrieveIndexAttributes btrieveIndexAttributes;
   BtrieveKeySegment btrieveKeySegment;

   // If SetField() fails.
   if ((status = btrieveKeySegment.SetField(0, 1, Btrieve::DATA_TYPE_UNSIGNED_BINARY)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveKeySegment::SetField():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

   // If AddKeySegment() fails.
   if ((status = btrieveIndexAttributes.AddKeySegment(&btrieveKeySegment)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveIndexAttributes::AddKeySegment():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

   // If IndexCreate() fails.
   if ((status = btrieveFile->IndexCreate(&btrieveIndexAttributes)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      printf("Error: BtrieveFile::IndexCreate():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

leave:
   return status;
}

static Btrieve::StatusCode
retrieveRecord(BtrieveFile *btrieveFile, uint8_t *key)
{
   Btrieve::StatusCode status = Btrieve::STATUS_CODE_NO_ERROR;
   record_t record;

   // If RecordRetrieve() fails.
   if (btrieveFile->RecordRetrieve(Btrieve::COMPARISON_EQUAL, Btrieve::INDEX_1, (char *)key, sizeof(*key), (char *)&record, RECORD_MAXIMUM_TOTAL_SIZE) < RECORD_FIXED_SIZE)
   {
      status = btrieveFile->GetLastStatusCode();
      printf("Error: BtrieveFile::RecordRetrieve():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

   printf("record: (%u, %u, %f, %s)\n", record.fixed.x, record.fixed.xSquared, record.fixed.xSquareRoot, record.text);

leave:
   return status;
}

int
main(int argc, char *argv[])
{
   static const char *usage = "Usage: %s uint8_value\n";

   BtrieveClient btrieveClient;
   Btrieve::StatusCode status = Btrieve::STATUS_CODE_UNKNOWN;
   BtrieveFile btrieveFile;
   uint8_t key;
   uint64_t integerValue;

   // If the incorrect number of arguments were given.
   if (argc != 2)
   {
      printf(usage, argv[0]);
      goto leave;
   }

   integerValue = atoi(argv[1]);

   // If integerValue is out of range.
   if ((integerValue < MIN_X) || (integerValue > MAX_X))
   {
      printf(usage, argv[0]);
      goto leave;
   }

   key = (uint8_t)integerValue;

   // If createFile() fails.
   if ((status = createFile(&btrieveClient)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

   // If openFile() fails.
   if ((status = openFile(&btrieveClient, &btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

   // If loadFile() fails.
   if ((status = loadFile(&btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

   // If createIndex() fails.
   if ((status = createIndex(&btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

   // If retrieveRecord() fails.
   if ((status = retrieveRecord(&btrieveFile, &key)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

   // If closeFile() fails.
   if ((status = closeFile(&btrieveClient, &btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

   // If deleteFile() fails.
   if ((status = deleteFile(&btrieveClient)) != Btrieve::STATUS_CODE_NO_ERROR)
   {
      goto leave;
   }

leave:
   // If there wasn't a failure.
   if (status == Btrieve::STATUS_CODE_NO_ERROR)
      return 0;

   return 1;
}