btestchunk.cpp

これは、btest.cpp に基づくレコード チャンクの更新および取得の例です。

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

#include "btrieveCpp.h"

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

#define MIN_X 0
#define MAX_X 255

#pragma pack(1)
typedef struct {
        uint8_t x;
        uint16_t xSquared;
        double xSquareRoot;
} chunk_t;
#pragma pack()

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

   // If SetFixedRecordLength() fails.
   if ((status = btrieveFileAttributes.SetFixedRecordLength(sizeof(chunk_t))) != 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;
   chunk_t chunk;
   int i;

   chunk.x = 0;
   chunk.xSquared = 0;
   chunk.xSquareRoot = 0;

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

   for (i = MIN_X; i <= MAX_X; i++)
   {
      chunk.x = (uint8_t)i;
      chunk.xSquared = (uint16_t)(i * i);
      chunk.xSquareRoot = sqrt((double)i);
 
      // If this is the first chunk.
      if (i == MIN_X)
      {
         // If RecordUpdateChunk() fails.
         if ((status = btrieveFile->RecordUpdateChunk(0, (char *)&chunk, sizeof(chunk))) != Btrieve::STATUS_CODE_NO_ERROR)
         {
            printf("Error: BtrieveFile::RecordUpdateChunk():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
            goto leave;
         }
      }
      else
      {
         // If RecordUpdateChunk() fails.
         if ((status = btrieveFile->RecordUpdateChunk((char *)&chunk, sizeof(chunk))) != Btrieve::STATUS_CODE_NO_ERROR)
         {
            printf("Error: BtrieveFile::RecordUpdateChunk():%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
retrieveRecord(BtrieveFile *btrieveFile, uint8_t *key)
{
   Btrieve::StatusCode status = Btrieve::STATUS_CODE_NO_ERROR;
   chunk_t chunk;
   int i;

   // If RecordRetrieveFirst() fails.
   if (btrieveFile->RecordRetrieveFirst(Btrieve::INDEX_NONE, (char *)&chunk, sizeof(chunk)) != sizeof(chunk))
   {
      status = btrieveFile->GetLastStatusCode();
      printf("Error: BtrieveFile::RecordRetrieveFirst():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
      goto leave;
   }

   for (i = MIN_X; i <= MAX_X; i++)
   {
      chunk.x = 0;
      chunk.xSquared = 0;
      chunk.xSquareRoot = 0;
 
      // If this is the first chunk.
      if (i == MIN_X)
      {
         // If RecordRetrieveChunk() fails.
         if (btrieveFile->RecordRetrieveChunk(0, sizeof(chunk), (char *)&chunk, sizeof(chunk)) != sizeof(chunk))
         {
            status = btrieveFile->GetLastStatusCode();
            printf("Error: BtrieveFile::RecordRetrieveChunk():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
            goto leave;
         }
      }
      else
      {
         // If RecordRetrieveChunk() fails.
         if (btrieveFile->RecordRetrieveChunk(sizeof(chunk), (char *)&chunk, sizeof(chunk)) != sizeof(chunk))
         {
            status = btrieveFile->GetLastStatusCode();
            printf("Error: BtrieveFile::RecordRetrieveChunk():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
            goto leave;
         }
      }

      // If key has been found.
      if (chunk.x == *key)
      {
         break;
      }
   }

   printf("chunk: (%u, %u, %f)\n", chunk.x, chunk.xSquared, chunk.xSquareRoot);

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 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;
}