// **********************************************************
// Delete a record from a page. Returns OK if everything went okay.
// Compacts remaining records but leaves a hole in the slot array.
// Use memmove() rather than memcpy() as space may overlap.
Status HFPage::deleteRecord(const RID& rid)
{
// fill in the body
//--- deal with errors ----
if(rid.pageNo < 0 || rid.slotNo < 0)
return MINIBASE_FIRST_ERROR(HEAPFILE, INVALID_SLOTNO);
//return FAIL;
if(rid.slotNo >= this->slotCnt)
return MINIBASE_FIRST_ERROR(HEAPFILE, INVALID_SLOTNO);
//return FAIL;
//--- deal with empty page case ---
if(empty())
return MINIBASE_FIRST_ERROR(HEAPFILE, NO_RECORDS);
//return FAIL;
//--- get record offset ---
int offset = getRecordOffset(rid);
//--- clean corresponding slot & get record length---
int len = cleanSlot(rid);
//--- deal with already deleted case ---
if(offset == INVALID_SLOT || len == EMPTY_SLOT)
return MINIBASE_FIRST_ERROR(HEAPFILE, ALREADY_DELETED);
//return FAIL;
//-- shrink slot directory ---
shrinkSlotDir();
//--- delete record & relocate behind records & slot dir ---
//--- & update usedPtr, freeSpace -----
deleteRec(offset, len);
return OK;
}
char* Page::getRecord ( int index ){
int offset = getRecordOffset( index );
int length = getRecordLength( index );
tempStrCounter = length;
memcpy( tempStr, content + offset, sizeof( char ) * length );
tempStr[ length ] = '\0';
return tempStr;
}
// **********************************************************
// Delete a record from a page. Returns OK if everything went okay.
// Compacts remaining records but leaves a hole in the slot array.
// Use memmove() rather than memcpy() as space may overlap.
Status HFPage::deleteRecord(const RID& rid)
{
// fill in the body
//---?? 注意未处理delete不存在record得特殊情况----
//--- get record offset ---
int offset = getRecordOffset(rid);
//--- clean corresponding slot & get record length---
int len = cleanSlot(rid);
//-- shrink slot directory ---
shrinkSlotDir();
//--- delete record & relocate behind records & slot dir ---
//--- & update usedPtr, freeSpace -----
deleteRec(offset, len);
return OK;
}
//compress a page, used for split page
void Page::adjustPage( ){
int nextFree = 4;
int slotSize = getSlotNumber();
int length, offset;
int counter = getSlotNumber();
int location = 0;
for ( int i = 0; i < slotSize; i ++ )
{
length = getRecordLength( i );
//if the length is -1,it means that this data not in this page
if ( length == -1 ) counter --;
else{
bool flag = 0;
//find a slot with record length of -1,if it succeed, then move the data into this slot
for (int j = location; j < i; j ++ )
if ( getRecordLength( j ) == -1 ) { location = j; flag = 1; break; }
if ( flag == 1 ){
offset = getRecordOffset( i );
memcpy( content + nextFree, content + offset, sizeof( char ) * length );
setRecordOffset( location, nextFree );
setRecordLength( location, length );
setRecordLength( i, -1 );
}
nextFree += length;
}
}
//update free offset and slot number
setSlotNumber( counter );
setFreeOffset( nextFree );
}
XAttrList* getAllExtendedAttributes(HFSCatalogNodeID CNID, Volume* volume) {
BTree* tree;
HFSPlusAttrKey key;
HFSPlusAttrRecord* record;
uint32_t nodeNumber;
int recordNumber;
BTNodeDescriptor* descriptor;
HFSPlusAttrKey* currentKey;
off_t recordOffset;
XAttrList* list = NULL;
XAttrList* lastItem = NULL;
XAttrList* item = NULL;
if(!volume->attrTree)
return NULL;
memset(&key, 0 , sizeof(HFSPlusAttrKey));
key.fileID = CNID;
key.startBlock = 0;
key.name.length = 0;
key.keyLength = sizeof(HFSPlusAttrKey) - sizeof(HFSUniStr255) + sizeof(key.name.length) + (sizeof(uint16_t) * key.name.length);
tree = volume->attrTree;
record = (HFSPlusAttrRecord*) search(tree, (BTKey*)(&key), NULL, &nodeNumber, &recordNumber);
if(record == NULL)
return NULL;
free(record);
while(nodeNumber != 0) {
descriptor = readBTNodeDescriptor(nodeNumber, tree);
while(recordNumber < descriptor->numRecords) {
recordOffset = getRecordOffset(recordNumber, nodeNumber, tree);
currentKey = (HFSPlusAttrKey*) READ_KEY(tree, recordOffset, tree->io);
if(currentKey->fileID == CNID) {
item = (XAttrList*) malloc(sizeof(XAttrList));
item->name = (char*) malloc(currentKey->name.length + 1);
int i;
for(i = 0; i < currentKey->name.length; i++) {
item->name[i] = currentKey->name.unicode[i];
}
item->name[currentKey->name.length] = '\0';
item->next = NULL;
if(lastItem != NULL) {
lastItem->next = item;
} else {
list = item;
}
lastItem = item;
free(currentKey);
} else {
free(currentKey);
free(descriptor);
return list;
}
recordNumber++;
}
nodeNumber = descriptor->fLink;
recordNumber = 0;
free(descriptor);
}
return list;
}
CatalogRecordList* getFolderContents(HFSCatalogNodeID CNID, Volume* volume) {
BTree* tree;
HFSPlusCatalogThread* record;
HFSPlusCatalogKey key;
uint32_t nodeNumber;
int recordNumber;
BTNodeDescriptor* descriptor;
off_t recordOffset;
off_t recordDataOffset;
HFSPlusCatalogKey* currentKey;
CatalogRecordList* list;
CatalogRecordList* lastItem;
CatalogRecordList* item;
char pathBuffer[1024];
HFSPlusCatalogRecord* toReturn;
HFSPlusCatalogKey nkey;
int exact;
tree = volume->catalogTree;
key.keyLength = sizeof(key.parentID) + sizeof(key.nodeName.length);
key.parentID = CNID;
key.nodeName.length = 0;
list = NULL;
record = (HFSPlusCatalogThread*) search(tree, (BTKey*)(&key), NULL, &nodeNumber, &recordNumber);
if(record == NULL)
return NULL;
free(record);
++recordNumber;
while(nodeNumber != 0) {
descriptor = readBTNodeDescriptor(nodeNumber, tree);
while(recordNumber < descriptor->numRecords) {
recordOffset = getRecordOffset(recordNumber, nodeNumber, tree);
currentKey = (HFSPlusCatalogKey*) READ_KEY(tree, recordOffset, tree->io);
recordDataOffset = recordOffset + currentKey->keyLength + sizeof(currentKey->keyLength);
if(currentKey->parentID == CNID) {
item = (CatalogRecordList*) malloc(sizeof(CatalogRecordList));
item->name = currentKey->nodeName;
item->record = (HFSPlusCatalogRecord*) READ_DATA(tree, recordDataOffset, tree->io);
if(item->record->recordType == kHFSPlusFileRecord && (((HFSPlusCatalogFile*)item->record)->userInfo.fileType) == kHardLinkFileType) {
sprintf(pathBuffer, "iNode%d", ((HFSPlusCatalogFile*)item->record)->permissions.special.iNodeNum);
nkey.parentID = volume->metadataDir;
ASCIIToUnicode(pathBuffer, &nkey.nodeName);
nkey.keyLength = sizeof(nkey.parentID) + sizeof(nkey.nodeName.length) + (sizeof(uint16_t) * nkey.nodeName.length);
toReturn = (HFSPlusCatalogRecord*) search(volume->catalogTree, (BTKey*)(&nkey), &exact, NULL, NULL);
free(item->record);
item->record = toReturn;
}
item->next = NULL;
if(list == NULL) {
list = item;
} else {
lastItem->next = item;
}
lastItem = item;
free(currentKey);
} else {
free(currentKey);
free(descriptor);
return list;
}
recordNumber++;
}
nodeNumber = descriptor->fLink;
recordNumber = 0;
free(descriptor);
}
return list;
}
CatalogRecordList* getFolderContents(HFSCatalogNodeID CNID, Volume* volume) {
BTree* tree;
HFSPlusCatalogThread* record;
HFSPlusCatalogKey key;
uint32_t nodeNumber;
int recordNumber;
BTNodeDescriptor* descriptor;
off_t recordOffset;
off_t recordDataOffset;
HFSPlusCatalogKey* currentKey;
CatalogRecordList* list;
CatalogRecordList* lastItem;
CatalogRecordList* item;
tree = volume->catalogTree;
key.keyLength = sizeof(key.parentID) + sizeof(key.nodeName.length);
key.parentID = CNID;
key.nodeName.length = 0;
list = NULL;
record = (HFSPlusCatalogThread*) search(tree, (BTKey*)(&key), NULL, &nodeNumber, &recordNumber);
if(record == NULL)
return NULL;
free(record);
++recordNumber;
while(nodeNumber != 0) {
descriptor = readBTNodeDescriptor(nodeNumber, tree);
while(recordNumber < descriptor->numRecords) {
recordOffset = getRecordOffset(recordNumber, nodeNumber, tree);
currentKey = (HFSPlusCatalogKey*) READ_KEY(tree, recordOffset, tree->io);
recordDataOffset = recordOffset + currentKey->keyLength + sizeof(currentKey->keyLength);
if(currentKey->parentID == CNID) {
item = (CatalogRecordList*) malloc(sizeof(CatalogRecordList));
item->name = currentKey->nodeName;
item->record = (HFSPlusCatalogRecord*) READ_DATA(tree, recordDataOffset, tree->io);
item->next = NULL;
if(list == NULL) {
list = item;
} else {
lastItem->next = item;
}
lastItem = item;
free(currentKey);
} else {
free(currentKey);
free(descriptor);
return list;
}
recordNumber++;
}
nodeNumber = descriptor->fLink;
recordNumber = 0;
free(descriptor);
}
return list;
}
