/* error code*/
int FMM_HEAD_GetFirstEmpty(int fileDesc)
{
int i=0;
int tempBitfield; /* We don't want to destroy the information in here, so make a copy */
int bitNumber = 0; /* The position of the first bit that is 1 */
int check=128; /* binary value: 10000000 */
if ( FMM_IsValid(fileDesc) == FALSE ){ /* check if fileDesc is valid */
BF_Errno=BFE_FD;
return BFE_FD;
}
while ( file_headers[file_openings[fileDesc].header].header[i] == 255 /* pass by bytes reffered to blocks in use. */
&& i < BF_BLOCK_SIZE )
i++;
if ( i == BF_BLOCK_SIZE ){ /* all blocks VALID */
BF_Errno=BFE_EOF;
return BFE_EOF;
}
tempBitfield=file_headers[file_openings[fileDesc].header].header[i]; /* first byte cointaining bit indicating invalid block */
while ((~tempBitfield & check) == 0 && bitNumber < 8 ){ /* find bit possition */
check>>=1;
bitNumber++;
}
return ( 8*i + bitNumber ); /* return block number */
}
/* error code, else return BFE_OK. */
int FMM_GetFileInfoByFD(fileInfo_t* finfo)
{
if ( FMM_IsValid(finfo->fd) == FALSE ){ /* check validy of fd */
BF_Errno= BFE_FD;
return BFE_FD ;
}
finfo->fp=file_openings[finfo->fd].fp;
bzero(finfo->filename,MAX_FILE_NAME );
strcpy(finfo->filename,file_headers[file_openings[finfo->fd].header].name);
return BFE_OK;
}
/* returning true or false. */
BOOLEAN FMM_HEAD_IsValid(int fileDesc, int blockNum)
{
int tempBitfield; /* We don't want to destroy the information, make a copy */
if ( FMM_IsValid(fileDesc) == FALSE ){
BF_Errno=BFE_FD;
return BFE_FD;
}
tempBitfield=file_headers[file_openings[fileDesc].header].header[blockNum/8]; /* appropriate byte, reffered to blockNum */
tempBitfield = tempBitfield>>(7-blockNum%8); /* bitwise operation */
if ( (tempBitfield & 1 ) == 1 )
return TRUE;
else
return FALSE;
}
/* Otherwise setting errno and returning error code. */
int FMM_HEAD_Set(int fileDesc, int blockNum, BOOLEAN value)
{
if ( FMM_IsValid(fileDesc) == FALSE ){ /* check validy of fileDesc */
BF_Errno=BFE_FD;
return BFE_FD;
}
else if ( blockNum >= MAX_BLOCKS){ /* check validy of blockNum */
BF_Errno=BFE_INVALIDBLOCK;
return BFE_INVALIDBLOCK ;
}
if ( value == TRUE ) /* set appropriate bit TRUE (1) */
file_headers[file_openings[fileDesc].header].header[blockNum/8] |=1<<(7-blockNum%8); /* blockNums are 0,1,2,...,7 */
else if ( value == FALSE ) /* set appropriate bit FALSE (0) */
file_headers[file_openings[fileDesc].header].header[blockNum/8] &=~(1<<(7-blockNum%8)); /* blockNums are 0,1,2,...,7 */
file_headers[file_openings[fileDesc].header].dirty=1;
return BFE_OK;
}
/* returning error code. */
int FMM_HEAD_GetNextBlock(int fileDesc, int prev)
{
int i;
int tempBitfield; /* We don't want to destroy the information in here, so make a copy */
int bitNumber; /* The position of the first bit that is 1 */
int check=128; /* binary value: 10000000 */
if ( FMM_IsValid(fileDesc) == FALSE ){ /* check if fileDesc is valid */
BF_Errno=BFE_FD;
return BFE_FD;
}
if ( prev == MAX_BLOCKS-1){ /* check validy of previous blockNum */
BF_Errno=BFE_HEADOVERFLOW;
return BFE_HEADOVERFLOW;
}
i=(prev+1)/8; /* find byte reffering to block after prev */
tempBitfield=file_headers[file_openings[fileDesc].header].header[i];
check>>=(prev+1)%8;
bitNumber=(prev+1)%8;
while ( bitNumber < 8 ){
if ( (tempBitfield & check) != 0 )
return ( 8*i + bitNumber );
check>>=1;
bitNumber++;
}
i++;
bitNumber=0;
check=128;
while ( file_headers[file_openings[fileDesc].header].header[i] == 0 /* pass by bytes reffered to blocks NOT in use. */
&& i < MAX_BLOCKS )
i++;
if ( prev == MAX_BLOCKS-1){ /* all blocks INVALID */
BF_Errno=BFE_HEADOVERFLOW;
return BFE_HEADOVERFLOW;
}
tempBitfield=file_headers[file_openings[fileDesc].header].header[i];
while ( bitNumber < 8 ){
if ( (tempBitfield & check) != 0 )
return ( 8*i + bitNumber );
check>>=1;
bitNumber++;
}
return ( 8*i + bitNumber );
}
/* error code, else return BFE_OK. */
int FMM_Close(int fileDesc)
{
int RetVal;
if ( FMM_IsValid(fileDesc) == FALSE ){ /* check validy of fileDesc */
BF_Errno=BFE_FD;
return BFE_FD;
}
file_headers[file_openings[fileDesc].header].openings--; /* decrease counter of file openings reffering to current header */
if ( file_headers[file_openings[fileDesc].header].openings == 0 /* if no file opening reffers to current header and header has */
&& file_headers[file_openings[fileDesc].header].dirty == 1 ) /* been changed, write it back to file. */
if ( (RetVal=HDF_WriteBlock(0, file_headers[file_openings[fileDesc].header].header, file_openings[fileDesc].fp)) != BFE_OK )
return RetVal;
file_openings[fileDesc].empty=1; /* set current position as empty */
if ( (RetVal=HDF_CloseFile(file_openings[fileDesc].fp)) != BFE_OK ) /* closing, using file pointer */
return RetVal;
return BFE_OK;
}
int main(void) {
int rvalue;
FILE *fp;
char *buffer;
int fd;
fileInfo_t finfo;
char athlete[ATHLETE_SIZE];
int offset;
int blockNumInFile1;
int blockNumInHeader1;
int blockNumInFile2;
int blockNumInHeader2;
int firstValid;
int secondValid;
// ---------------------- HDF epipedo ----------------------
// Elegxos an yparxei to fileName
printf("\nChecking if file %s exists...\n\n", fileName);
if (HDF_ExistsFile(fileName) == TRUE) {
printf("Checkpoint 1:\n");
printf("HDF_ExistsFile returned TRUE!\n\n");
}
// Dimiourgia tou arxeiou fileName
printf("Creating file %s...\n\n", fileName);
if ( (rvalue=HDF_CreateFile(fileName)) != BFE_OK) {
printf("Checkpoint 2:\n");
printf("HDF_CreateFile() returned %d!\n\n", rvalue);
}
// Anoigma tou arxeiou fileName
printf("Opening file %s...\n\n", fileName);
if ((rvalue = HDF_OpenFile(fileName,&fp)) != BFE_OK)
{
printf("Checkpoint 3:\n");
printf("HDF_OpenFile() returned %d, should have returned 0!\n\n",rvalue);
}
// Dimiourgia epikefalidas tou arxeiou sti mnimi
buffer = malloc(sizeof(char) * BF_BLOCK_SIZE);
memset(buffer, 0, BF_BLOCK_SIZE);
// Antigrafi epikefalidas sto block 0 tou arxeiou
printf("Writing file header to disk...\n\n");
if ((rvalue = HDF_WriteBlock(0, buffer, fp)) != BFE_OK)
{
printf("Checkpoint 4:");
printf("HDF_WriteBlock() returned %d!\n\n",rvalue);
}
// Kleisimo tou arxeiou fileName
printf("Closing file %s\n\n", fileName);
if ((rvalue = HDF_CloseFile(fp)) != BFE_OK)
{
printf("Checkpoint 5:\n");
printf("HDF_CloseFile() returned %d!\n\n", rvalue);
}
// ---------------------- FMM epipedo ----------------------
FMM_Init();
// Anoigma tou arxeiou
printf("Opening file %s...\n\n", fileName);
if ((fd = FMM_Open(fileName)) < 0) {
printf("Checkpoint 6:\n");
printf("FMM_Open() returned %d!\n\n", fd);
}
// Elegxos an i thesi fd tou pinaka anoixtwn arxeiwn einai pleon egkyri kataxwrisi arxeiou
printf("Checking for validity of position %d of open files array...\n\n", fd);
if (FMM_IsValid(fd) != TRUE) {
printf("Checkpoint 7:\n");
printf("FMM_IsValid() returned FALSE!\n\n");
}
// Anaktisi pliroforias gia to arxeio me vasi to onoma
strcpy(finfo.filename, fileName);
printf("Retrieving file information by name...\n\n");
if ((rvalue = FMM_GetFileInfoByName(&finfo)) != BFE_OK) {
printf("Checkpoint 8:\n");
printf("FMM_GetFileInfoByName() returned %d!\n\n", rvalue);
}
printFileInfo(&finfo);
// Anaktisi pliroforias gia to arxeio me vasi to fd
finfo.fd = fd;
printf("Retrieving file information by file descriptor...\n\n");
if ((rvalue = FMM_GetFileInfoByFD(&finfo)) != BFE_OK) {
printf("Checkpoint 9:\n");
printf("FMM_GetFileInfoByFD() returned %d!\n\n", rvalue);
}
printFileInfo(&finfo);
// Dimiourgia enos neou block sti mnimi
memset(buffer, 0, BF_BLOCK_SIZE);
offset = 0;
strcpy(athlete, "Periklis Iakovakis");
memcpy(buffer + offset, athlete, ATHLETE_SIZE);
offset += ATHLETE_SIZE;
strcpy(athlete, "Pyrros Dimas");
memcpy(buffer + offset, athlete, ATHLETE_SIZE);
offset += ATHLETE_SIZE;
strcpy(athlete, "Helena Isinbayeva");
memcpy(buffer + offset, athlete, ATHLETE_SIZE);
offset += ATHLETE_SIZE;
strcpy(athlete, "Blanka Vlasic");
memcpy(buffer + offset, athlete, ATHLETE_SIZE);
// Grapsimo aytou tou block sto arxeio sti thesi blockNumInFile
fp = finfo.fp;
blockNumInFile1 = 5;
printf("Writing block to disk...\n\n");
if ((rvalue = HDF_WriteBlock(blockNumInFile1, buffer, fp)) != BFE_OK)
{
printf("Checkpoint 10:");
printf("HDF_WriteBlock() returned %d!\n\n",rvalue);
}
// Enimerwsi tis epikefalidas tou arxeiou oti to block ayto einai pleon egkyro
blockNumInHeader1 = blockNumInFile1 - 1; // PROSOXH SE AYTO!!!
printf("Updating header...\n\n");
if ((rvalue = FMM_HEAD_Set(fd, blockNumInHeader1, TRUE)) != BFE_OK) {
printf("Checkpoint 11:");
printf("FMM_HEAD_Set() returned %d!\n\n",rvalue);
}
// Elegxos an enimerwthike i epikefalida
printf("Checking header...\n\n");
if (FMM_HEAD_IsValid(fd, blockNumInHeader1) == FALSE) {
printf("Checkpoint 12:");
printf("FMM_HEAD_isValid() returned %d!\n\n",rvalue);
}
// Anaktisi tou prwtou egkyrou block tou arxeiou
printf("Retrieving first valid block...\n\n");
if ((firstValid = FMM_HEAD_GetFirstBlock(fd)) == BFE_EOF) {
printf("Checkpoint 13:");
printf("FMM_HEAD_GetFirstBlock returned %d!\n\n",rvalue);
}
printf("firstValid = %d, it should be equal to %d\n\n", firstValid, blockNumInHeader1);
// Dimiourgia enos 2ou neou block sti mnimi
memset(buffer, 0, BF_BLOCK_SIZE);
offset = 0;
strcpy(athlete, "Vasilis Spanoulis");
memcpy(buffer + offset, athlete, ATHLETE_SIZE);
offset += ATHLETE_SIZE;
strcpy(athlete, "Sofoklis Sxortsianitis");
memcpy(buffer + offset, athlete, ATHLETE_SIZE);
// Grapsimo aytou tou block sto arxeio sti thesi blockNumInFile
blockNumInFile2 = 3;
printf("Writing block to disk...\n\n");
if ((rvalue = HDF_WriteBlock(blockNumInFile2, buffer, fp)) != BFE_OK)
{
printf("Checkpoint 14:");
printf("HDF_WriteBlock() returned %d!\n\n",rvalue);
}
// Enimerwsi tis epikefalidas tou arxeiou oti to block ayto einai pleon egkyro
blockNumInHeader2 = blockNumInFile2 - 1; // PROSOXH SE AYTO!!!
printf("Updating header...\n\n");
if ((rvalue = FMM_HEAD_Set(fd, blockNumInHeader2, TRUE)) != BFE_OK) {
printf("Checkpoint 15:");
printf("FMM_HEAD_Set() returned %d!\n\n",rvalue);
}
// Anaktisi tou prwtou egkyrou block tou arxeiou
printf("Retrieving first valid block...\n\n");
if ((firstValid = FMM_HEAD_GetFirstBlock(fd)) == BFE_EOF) {
printf("Checkpoint 16:");
printf("FMM_HEAD_GetFirstBlock returned %d!\n\n",rvalue);
}
printf("firstValid = %d, it should be equal to %d\n\n", firstValid, blockNumInHeader2);
// Anaktisi tou prwtou egkyrou block tou arxeiou meta apo to firstValid
printf("Retrieving first valid block after block %d...\n\n", firstValid);
if ((secondValid = FMM_HEAD_GetNextBlock(fd, firstValid)) == BFE_EOF) {
printf("Checkpoint 17:");
printf("FMM_HEAD_GetFirstBlock returned %d!\n\n",rvalue);
}
printf("secondValid = %d, it should be equal to %d\n\n", secondValid, blockNumInHeader1);
// Kleisimo arxeiou
printf("Closing file %s...\n\n", fileName);
if ((rvalue = FMM_Close(fd)) != BFE_OK) {
printf("Checkpoint 19:\n");
printf("FMM_Close() returned %d!\n\n", rvalue);
}
free(buffer);
return 0;
}
