/**
* Return the id of the table with a specified name,
*
* @throws NoSuchElementException if the table doesn't exist
*/
public int getTableId(String name) throws NoSuchElementException {
// some code goes here
DbFile tableID = tableFile.get(name);
if (tableID == null) throw new NoSuchElementException();
// System.out.println(tableID.getId());
else return tableID.getId();
}
/**
* Returns the DbFile that can be used to read the contents of the specified table.
*
* @param tableid The id of the table, as specified by the DbFile.getId() function passed to
* addTable
*/
public DbFile getDbFile(int tableid) throws NoSuchElementException {
// some code goes here
String fileName = fileId.get(tableid);
if (fileName.equals(null)) throw new NoSuchElementException();
DbFile retFile = tableFile.get(fileName);
if (retFile.equals(null)) throw new NoSuchElementException();
else return retFile;
}
/**
* Returns the tuple descriptor (schema) of the specified table
*
* @param tableid The id of the table, as specified by the DbFile.getId() function passed to
* addTable
* @throws NoSuchElementException if the table doesn't exist
*/
public TupleDesc getTupleDesc(int tableid) throws NoSuchElementException {
// some code goes here
String fileName = fileId.get(tableid);
if (fileName.equals(null)) throw new NoSuchElementException();
DbFile retTD = tableFile.get(fileName);
if (retTD.equals(null)) throw new NoSuchElementException();
// System.out.println(retTD);
else return retTD.getTupleDesc();
}
/**
* Create a new TableStats object, that keeps track of statistics on each column of a table
*
* @param tableid The table over which to compute statistics
* @param ioCostPerPage The cost per page of IO. This doesn't differentiate between
* sequential-scan IO and disk seeks.
*/
public TableStats(int tableid, int ioCostPerPage) {
// For this function, we use the DbFile for the table in question,
// then scan through its tuples and calculate the values that you
// to build the histograms.
// TODO: Fill out the rest of the constructor.
// Feel free to change anything already written, it's only a guideline
this.ioCostPerPage = ioCostPerPage;
DbFile file = Database.getCatalog().getDbFile(tableid);
tupleDesc = file.getTupleDesc();
numPages = ((HeapFile) file).numPages();
numTuples = 0;
int numFields = tupleDesc.numFields();
// TODO: what goes here?
statistics = new ArrayList<Object>();
for (int i = 0; i < numFields; i++) {
if (Type.INT_TYPE.equals(tupleDesc.getFieldType(i))) {
statistics.add(new IntStatistics(NUM_HIST_BINS));
} else {
statistics.add(new StringHistogram(NUM_HIST_BINS));
}
}
final DbFileIterator iter = file.iterator(null);
try {
iter.open();
while (iter.hasNext()) {
Tuple t = iter.next();
numTuples++;
// TODO: and here?
for (int i = 0; i < numFields; i++) {
if (Type.INT_TYPE.equals(tupleDesc.getFieldType(i))) {
((IntStatistics) statistics.get(i)).addValue(((IntField) t.getField(i)).getValue());
} else {
((StringHistogram) statistics.get(i))
.addValue(((StringField) t.getField(i)).getValue());
}
}
}
iter.close();
} catch (DbException e) {
e.printStackTrace();
} catch (TransactionAbortedException e) {
e.printStackTrace();
}
}
/**
* Retrieve the specified page with the associated permissions. Will acquire a lock and may block
* if that lock is held by another transaction.
*
* <p>The retrieved page should be looked up in the buffer pool. If it is present, it should be
* returned. If it is not present, it should be added to the buffer pool and returned. If there is
* insufficient space in the buffer pool, an page should be evicted and the new page should be
* added in its place.
*
* @param tid the ID of the transaction requesting the page
* @param pid the ID of the requested page
* @param perm the requested permissions on the page
* @throws DbException
* @throws TransactionAbortedException
*/
public Page getPage(TransactionId tid, PageId pid, Permissions perm)
throws DbException, TransactionAbortedException {
lockManager.acquireLock(tid, pid, perm);
if (pageIdToPages.containsKey(pid)) {
return pageIdToPages.get(pid);
}
if (currentPages.get() == maxPages) {
evictPage();
}
int tableId = pid.getTableId();
Catalog catalog = Database.getCatalog();
DbFile dbFile = catalog.getDatabaseFile(tableId);
Page page = dbFile.readPage(pid);
pageIdToPages.put(pid, page);
currentPages.incrementAndGet();
return page;
}
/**
* Add a new table to the catalog. This table's contents are stored in the specified DbFile.
*
* @param file the contents of the table to add; file.getId() is the identfier of this
* file/tupledesc param for the calls getTupleDesc and getFile
* @param name the name of the table -- may be an empty string. May not be null. If a name
* @param pkeyField the name of the primary key field conflict exists, use the last table to be
* added as the table for a given name.
*/
public void addTable(DbFile file, String name, String pkeyField) throws IllegalArgumentException {
// some code goes here
if (file == null || name == null) {
throw new IllegalArgumentException();
} else {
// String[] tableAdd = {name, pkeyField};
tableFile.put(name, file);
tablepkey.put(name, pkeyField);
fileId.put(file.getId(), name);
}
}
public static void main(String args[])
throws DbException, TransactionAbortedException, IOException {
// convert a file
if (args[0].equals("convert")) {
try {
if (args.length == 3) {
HeapFileEncoder.convert(
new File(args[1]),
new File(args[1].replaceAll(".txt", ".dat")),
BufferPool.PAGE_SIZE,
Integer.parseInt(args[2]));
} else if (args.length == 4) {
ArrayList<Type> ts = new ArrayList<Type>();
String[] typeStringAr = args[3].split(",");
for (String s : typeStringAr) {
if (s.toLowerCase().equals("int")) ts.add(Type.INT_TYPE);
else if (s.toLowerCase().equals("string")) ts.add(Type.STRING_TYPE);
else {
System.out.println("Unknown type " + s);
return;
}
}
HeapFileEncoder.convert(
new File(args[1]),
new File(args[1].replaceAll(".txt", ".dat")),
BufferPool.PAGE_SIZE,
Integer.parseInt(args[2]),
ts.toArray(new Type[0]));
} else {
System.out.println("Unexpected number of arguments to convert ");
}
} catch (IOException e) {
throw new RuntimeException(e);
}
} else if (args[0].equals("print")) {
File tableFile = new File(args[1]);
int columns = Integer.parseInt(args[2]);
DbFile table = Utility.openHeapFile(columns, tableFile);
TransactionId tid = new TransactionId();
DbFileIterator it = table.iterator(tid);
if (null == it) {
System.out.println(
"Error: method HeapFile.iterator(TransactionId tid) not yet implemented!");
} else {
it.open();
while (it.hasNext()) {
Tuple t = it.next();
System.out.println(t);
}
it.close();
}
} else if (args[0].equals("parser")) {
// Strip the first argument and call the parser
String[] newargs = new String[args.length - 1];
for (int i = 1; i < args.length; ++i) {
newargs[i - 1] = args[i];
}
try {
// dynamically load Parser -- if it doesn't exist, print error message
Class<?> c = Class.forName("simpledb.Parser");
Class<?> s = String[].class;
java.lang.reflect.Method m = c.getMethod("main", s);
m.invoke(null, (java.lang.Object) newargs);
} catch (ClassNotFoundException cne) {
System.out.println(
"Class Parser not found -- perhaps you are trying to run the parser as a part of lab1?");
} catch (Exception e) {
System.out.println("Error in parser.");
e.printStackTrace();
}
} else {
System.err.println("Unknown command: " + args[0]);
System.exit(1);
}
}
