public static void createIndex(String tableName, Index index) {
Value table_ = cm.GetTableInformation(tableName);
Value attr_;
BPlusTree thisTree = new BPlusTree(index);
String filename = tableName;
try {
mapInsert(tableName, index);
RM_FileHandler rmf = RM_Manager.getInstance().openFile(filename);
RM_FileScan rmfs =
new RM_FileScan(
rmf, Constant.TYPE.INT, 4, 0, Constant.COMP_OP.NO_OP, PF_Manager.intTobyteArray(1));
RM_Record rmr = rmfs.getNextRec();
while (rmr != null) {
byte[] Record = rmr.getData();
byte[] key = getColumnValue(tableName, index, Record);
thisTree.insert(key, rmr.getRid().getPageNum(), rmr.getRid().getSlotNum());
rmr = rmfs.getNextRec();
}
} catch (NullPointerException e) {
e.printStackTrace();
System.err.println("must not be null for key.");
} catch (Exception e) {
e.printStackTrace();
System.err.println("the index has not been created.");
}
// index.rootNum=thisTree.myRootBlock.blockOffset;
setIndexRoot(index.indexName, thisTree.myRootBlock.getPageNum());
System.out.println("Create index successfully!");
}
public class IndexManager {
private static CatalogManager cm = CatalogManager.getInstance();
private static RM_Manager rm = RM_Manager.getInstance();
private static TreeMap<String, Integer> mapIndexRoot = new TreeMap<String, Integer>();
private static TreeMap<String, HashSet<Index>> mapName2Index =
new TreeMap<String, HashSet<Index>>();
/* public static Buffer buf;
IndexManager(Buffer buffer){
buf = buffer;
} */
private static IndexManager Instant = new IndexManager();
public static IndexManager getInstance() {
return Instant;
}
private static byte[] getColumnValue(String tableName, Index index, byte[] row) {
/* Value table_ = cm.GetTableInformation(tableName);
Value attr_;
int st = 0, en = 0;
for(int i = 0; i <= table_.getLength(); i++){
attr_ = cm.GetAttrInformation(tableName, i);
st = en;
en += attr_.getLength();
}*/
int st = 0, en = 0;
for (int i = 0; i < index.column; i++) {
st = en;
en += cm.GetAttrInformation(tableName, i).getLength();
}
byte[] colValue = new byte[en - st];
for (int j = 0; j < en - st; j++) {
colValue[j] = row[st + j];
}
return colValue;
}
static boolean mapInsert(String key, Index value) {
if (mapName2Index.containsKey(key)) {
HashSet<Index> set = mapName2Index.get(key);
if (set.contains(value)) return false;
set.add(value);
} else {
HashSet<Index> set = new HashSet<Index>();
set.add(value);
mapName2Index.put(key, set);
}
return true;
}
public static void createIndex(String tableName, Index index) {
Value table_ = cm.GetTableInformation(tableName);
Value attr_;
BPlusTree thisTree = new BPlusTree(index);
String filename = tableName;
try {
mapInsert(tableName, index);
RM_FileHandler rmf = RM_Manager.getInstance().openFile(filename);
RM_FileScan rmfs =
new RM_FileScan(
rmf, Constant.TYPE.INT, 4, 0, Constant.COMP_OP.NO_OP, PF_Manager.intTobyteArray(1));
RM_Record rmr = rmfs.getNextRec();
while (rmr != null) {
byte[] Record = rmr.getData();
byte[] key = getColumnValue(tableName, index, Record);
thisTree.insert(key, rmr.getRid().getPageNum(), rmr.getRid().getSlotNum());
rmr = rmfs.getNextRec();
}
} catch (NullPointerException e) {
e.printStackTrace();
System.err.println("must not be null for key.");
} catch (Exception e) {
e.printStackTrace();
System.err.println("the index has not been created.");
}
// index.rootNum=thisTree.myRootBlock.blockOffset;
setIndexRoot(index.indexName, thisTree.myRootBlock.getPageNum());
System.out.println("Create index successfully!");
}
public static void dropIndex(String filename) {
filename += ".index";
File file = new File(filename);
try {
if (file.exists()) {
if (file.delete()) System.out.println("The index file has been deleted.");
} else System.out.println("The file " + filename + " has not been found.");
} catch (Exception e) {
System.out.println(e.getMessage());
System.out.println("Delete index unsuccessfully！");
}
// buf.setInvalid(filename); //将buf中所有与此索引相关的缓冲块都置为无效
System.out.println("Delete index successfully！");
}
public static void dropTable(String filename) {
HashSet<Index> i = mapName2Index.get(filename);
for (Index j : i) {
dropIndex(j.indexName);
}
mapName2Index.remove(filename, i);
}
public static RID searchEqual(Index index, byte[] key) throws Exception {
RID off = new RID();
try {
// Index inx=CatalogManager.getIndex(index.indexName);
BPlusTree thisTree = new BPlusTree(index, index.rootNum); /*This place has bugs.*/
off = thisTree.searchKey(key);
return off;
} catch (NullPointerException e) {
System.err.println();
return null;
}
}
public static void insertKey(Index index, byte[] key, int blockOffset, int offset)
throws Exception {
try {
// Index inx=CatalogManager.getIndex(index.indexName);
BPlusTree thisTree = new BPlusTree(index, index.rootNum); /*This place has bugs.*/
thisTree.insert(key, blockOffset, offset);
// index.rootNum=thisTree.myRootBlock.blockOffset;
setIndexRoot(index.indexName, thisTree.myRootBlock.getPageNum());
} catch (NullPointerException e) {
System.err.println();
}
}
public static void deleteKey(Index index, byte[] deleteKey) throws Exception {
try {
// Index inx=CatalogManager.getIndex(index.indexName);
BPlusTree thisTree = new BPlusTree(index, index.rootNum); /*This place has bugs.*/
thisTree.delete(deleteKey);
// index.rootNum=thisTree.myRootBlock.blockOffset;
setIndexRoot(index.indexName, thisTree.myRootBlock.getPageNum());
} catch (NullPointerException e) {
System.err.println();
}
}
public static void setIndexRoot(String indexName, int number) {
;
if (mapIndexRoot.containsKey(indexName)) {
mapIndexRoot.replace(indexName, number);
} else mapIndexRoot.put(indexName, number);
}
// 获得索引根块在文件中的block偏移量， 如果该index不存在则返回-1
public static int getIndexRoot(String indexName) {
if (mapIndexRoot.containsKey(indexName)) return mapIndexRoot.get(indexName);
else return -1;
}
}