block.cpp

これは、レコードのロックおよびロック解除の例です。

#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;
} record_t;
#pragma pack()
createFile(BtrieveClient *btrieveClient)
{
BtrieveFileAttributes btrieveFileAttributes;
// If SetFixedRecordLength() fails.
if ((status = btrieveFileAttributes.SetFixedRecordLength(sizeof(record_t))) != Btrieve::STATUS_CODE_NO_ERROR)
{
printf("Error: BtrieveFileAttributes::SetFixedRecordLength():%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;
}
openFile(BtrieveClient *btrieveClient, BtrieveFile *btrieveFile)
{
// 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;
}
loadFile(BtrieveFile *btrieveFile)
{
int i;
record_t record;
for (i = MIN_X; i <= MAX_X; i++)
{
record.x = (uint8_t)i;
record.xSquared = (uint16_t)(i * i);
record.xSquareRoot = sqrt((double)i);
// If RecordCreate() fails.
if ((status = btrieveFile->RecordCreate((char *)&record, sizeof(record))) != Btrieve::STATUS_CODE_NO_ERROR)
{
printf("Error: BtrieveFile::RecordCreate():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
}
leave:
return status;
}
closeFile(BtrieveClient *btrieveClient, BtrieveFile *btrieveFile)
{
// 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;
}
deleteFile(BtrieveClient *btrieveClient)
{
// 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;
}
createIndex(BtrieveFile *btrieveFile)
{
BtrieveIndexAttributes btrieveIndexAttributes;
BtrieveKeySegment btrieveKeySegment;
// If SetField() fails.
{
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;
}
updateRecord(bool expectRecordInUse)
{
BtrieveClient btrieveClient(0x4233, 0);
BtrieveFile btrieveFile;
record_t record;
// If openFile() fails.
if ((status = openFile(&btrieveClient, &btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
{
goto leave;
}
// If RecordRetrieveFirst() fails.
if (btrieveFile.RecordRetrieveFirst(Btrieve::INDEX_1, (char *)&record, sizeof(record)) != sizeof(record))
{
status = btrieveFile.GetLastStatusCode();
printf("Error: Client2: BtrieveFile::RecordRetrieveFirst():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
record.xSquared++;
record.xSquareRoot++;
status = btrieveFile.RecordUpdate((char *)&record, sizeof(record));
if ((expectRecordInUse == true) && (status != Btrieve::STATUS_CODE_RECORD_INUSE))
{
printf("Error: Client2: BtrieveFile::RecordUpdate():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
else
if ((expectRecordInUse == false) && (status != Btrieve::STATUS_CODE_NO_ERROR))
{
printf("Error: Client2: BtrieveFile::RecordUpdate():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
// If closeFile() fails.
if ((status = closeFile(&btrieveClient, &btrieveFile)) != Btrieve::STATUS_CODE_NO_ERROR)
{
goto leave;
}
leave:
return status;
}
retrieveRecord(BtrieveFile *btrieveFile)
{
record_t record;
// If RecordRetrieveFirst() fails.
if (btrieveFile->RecordRetrieveFirst(Btrieve::INDEX_1, (char *)&record, sizeof(record), Btrieve::LOCK_MODE_SINGLE_WAIT) != sizeof(record))
{
status = btrieveFile->GetLastStatusCode();
printf("Error: BtrieveFile::RecordRetrieveFirst():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
printf("record before update: (%u, %u, %f)\n", record.x, record.xSquared, record.xSquareRoot);
// If updateRecord() fails.
if ((status = updateRecord(true)) != Btrieve::STATUS_CODE_NO_ERROR)
{
goto leave;
}
// If RecordUnlock() fails.
{
printf("Error: BtrieveFile::RecordUnlock():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
// If RecordRetrieveFirst() fails.
if (btrieveFile->RecordRetrieveFirst(Btrieve::INDEX_1, (char *)&record, sizeof(record)) != sizeof(record))
{
status = btrieveFile->GetLastStatusCode();
printf("Error: BtrieveFile::RecordRetrieveFirst():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
printf("record after update while locked: (%u, %u, %f)\n", record.x, record.xSquared, record.xSquareRoot);
// If updateRecord() fails.
if ((status = updateRecord(false)) != Btrieve::STATUS_CODE_NO_ERROR)
{
goto leave;
}
// If RecordRetrieveFirst() fails.
if (btrieveFile->RecordRetrieveFirst(Btrieve::INDEX_1, (char *)&record, sizeof(record), Btrieve::LOCK_MODE_SINGLE_WAIT) != sizeof(record))
{
status = btrieveFile->GetLastStatusCode();
printf("Error: BtrieveFile::RecordRetrieveFirst():%d:%s.\n", status, Btrieve::StatusCodeToString(status));
goto leave;
}
printf("record after update while unlocked: (%u, %u, %f)\n", record.x, record.xSquared, record.xSquareRoot);
leave:
return status;
}
int
main(int argc, char *argv[])
{
static const char *usage = "Usage: %s\n";
BtrieveClient btrieveClient;
BtrieveFile btrieveFile;
// If the incorrect number of arguments were given.
if (argc != 1)
{
printf(usage, argv[0]);
goto leave;
}
// 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)) != 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.
return 0;
return 1;
}