/**
* Reads a record from the file, given its id.
*
* @throws IllegalArgumentException if the rid is invalid
*/
public byte[] selectRecord(RID rid) {
PageId pid = rid.pageno;
if (!pids.contains(pid.pid)) throw new IllegalArgumentException("the RID is invalid");
Page page = new Page();
global.Minibase.BufferManager.pinPage(pid, page, false);
global.Minibase.BufferManager.unpinPage(pid, false);
return page.getData();
}
/**
* If the given name already denotes a file, this opens it; otherwise, this creates a new empty
* file. A null name produces a temporary heap file which requires no DB entry.
*/
public HeapFile(String name) throws ChainException {
this.name = name;
PageId firstPageId;
Page page = new Page();
pages = new ArrayList<PageId>();
pids = new HashSet<Integer>();
if (name == null) {
// Temporary heap file
firstPageId = global.Minibase.BufferManager.newPage(page, 1);
current = new HFPage(page);
current.setCurPage(firstPageId);
pages.add(firstPageId);
pids.add(firstPageId.pid);
global.Minibase.BufferManager.unpinPage(firstPageId, true);
} else {
firstPageId = global.Minibase.DiskManager.get_file_entry(name);
if (firstPageId == null) {
firstPageId = global.Minibase.BufferManager.newPage(page, 1);
global.Minibase.DiskManager.add_file_entry(name, firstPageId);
global.Minibase.BufferManager.unpinPage(firstPageId, true);
pages.add(firstPageId);
pids.add(firstPageId.pid);
global.Minibase.BufferManager.pinPage(firstPageId, page, false);
recordNumber = 0;
current = new HFPage(page);
current.setCurPage(firstPageId);
global.Minibase.BufferManager.unpinPage(firstPageId, true);
return;
}
// add the new HFPages
global.Minibase.BufferManager.pinPage(firstPageId, page, false);
// System.err.println("hahahaha"+page.getData());
current = new HFPage(page);
current.setData(page.getData());
pages.add(firstPageId);
pids.add(firstPageId.pid);
recordNumber += amount(current);
global.Minibase.BufferManager.unpinPage(firstPageId, false);
PageId currentPageId = current.getNextPage();
while (currentPageId.pid != 0 & currentPageId.pid != -1) {
HFPage temp = new HFPage();
global.Minibase.BufferManager.pinPage(currentPageId, temp, false);
pages.add(currentPageId);
pids.add(currentPageId.pid);
recordNumber += amount(temp);
global.Minibase.BufferManager.unpinPage(currentPageId, false);
currentPageId = temp.getNextPage();
}
}
}
/**
* Inserts a new record into the file and returns its RID.
*
* @throws IllegalArgumentException if the record is too large
*/
public RID insertRecord(byte[] record) throws IllegalArgumentException, ChainException {
if (record.length > GlobalConst.MAX_TUPSIZE)
throw new IllegalArgumentException("the record's size is too large");
for (int i = 0; i < pages.size(); i++) {
PageId pid = pages.get(i);
Page page = new Page();
global.Minibase.BufferManager.pinPage(pid, page, false);
HFPage hfpage = new HFPage(page);
hfpage.setCurPage(pid);
hfpage.setData(page.getData());
if (hfpage.getFreeSpace() > record.length) {
RID rid = hfpage.insertRecord(record);
recordNumber++;
global.Minibase.BufferManager.unpinPage(pid, true);
return rid;
}
global.Minibase.BufferManager.unpinPage(pid, false);
}
Page page = new Page();
PageId pid = global.Minibase.BufferManager.newPage(page, 1);
HFPage hfpage = new HFPage(page);
// initialize HFPage
hfpage.initDefaults();
hfpage.setCurPage(pid);
// hfpage.print();
RID rid = hfpage.insertRecord(record);
pages.add(pid);
pids.add(pid.pid);
hfpage.setNextPage(pid);
hfpage.setPrevPage(current.getCurPage());
current = hfpage;
global.Minibase.BufferManager.unpinPage(pid, true);
// hfpage.print();
// System.out.println ("The PID is "+pid);
recordNumber++;
return rid;
}
/**
* overrides the test4 function in TestDriver
*
* @return whether test4 has passed
*/
protected boolean test4() {
System.out.print("\n Test 4 exercises some of the internals " + "of the buffer manager\n");
int index;
int numPages = NUMBUF + 10;
Page pg = new Page();
PageId pid = new PageId();
PageId[] pids = new PageId[numPages];
boolean status = OK;
System.out.print(" - Allocate bunch of pages together \n");
for (int i = 0; i < numPages / NUMBUF; i++) {
for (index = i * NUMBUF; status == OK && index < (i + 1) * NUMBUF; ++index) {
pg = new Page();
try {
pid = SystemDefs.JavabaseBM.newPage(pg, 1);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not allocate new page number " + index + 1 + "\n");
e.printStackTrace();
}
if (status == OK) {
pids[index] = pid;
}
if (status == OK) {
// Copy the page number + 99999 onto each page. It seems
// unlikely that this bit pattern would show up there by
// coincidence.
int data = pid.pid + 99999;
try {
Convert.setIntValue(data, 0, pg.getpage());
} catch (IOException e) {
System.err.print("*** Convert value failed\n");
status = FAIL;
e.printStackTrace();
}
}
}
for (index = i * NUMBUF; status == OK && index < (i + 1) * NUMBUF; ++index) {
try {
SystemDefs.JavabaseBM.unpinPage(pids[index], true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin page " + pids[index].pid + "\n");
e.printStackTrace();
}
}
}
if (status == OK) {
System.out.print(" - Read the pages\n");
for (int i = 0; i < numPages / NUMBUF; i++) {
for (index = i * NUMBUF; status == OK && index < (i + 1) * NUMBUF; ++index) {
pg = new Page();
pid = pids[index];
try {
SystemDefs.JavabaseBM.pinPage(pid, pg, false);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not pin page " + pid.pid + "\n");
e.printStackTrace();
}
if (status == OK) {
int data = 0;
try {
data = Convert.getIntValue(0, pg.getpage());
} catch (IOException e) {
System.err.print("*** Convert value failed \n");
status = FAIL;
}
if (data != pid.pid + 99999) {
status = FAIL;
System.err.print("*** Read wrong data back from page " + pid.pid + "\n");
}
}
}
for (index = i * NUMBUF; status == OK && index < (i + 1) * NUMBUF; ++index) {
try {
SystemDefs.JavabaseBM.unpinPage(pids[index], true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin page " + pids[index].pid + "\n");
e.printStackTrace();
}
}
}
}
if (status == OK) {
System.out.print(" Test 4 completed successfully.\n");
}
return status;
}
/**
* overrides the test3 function in TestDriver. It exercises some of the internal of the buffer
* manager
*
* @return whether test3 has passed
*/
protected boolean test3() {
System.out.print("\n Test 3 exercises some of the internals " + "of the buffer manager\n");
int index;
int numPages = NUMBUF + 10;
Page pg = new Page();
PageId pid = new PageId();
PageId[] pids = new PageId[numPages];
boolean status = OK;
System.out.print(
" - Allocate and dirty some new pages, one at " + "a time, and leave some pinned\n");
for (index = 0; status == OK && index < numPages; ++index) {
try {
pid = SystemDefs.JavabaseBM.newPage(pg, 1);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not allocate new page number " + index + 1 + "\n");
e.printStackTrace();
}
if (status == OK) pids[index] = pid;
if (status == OK) {
// Copy the page number + 99999 onto each page. It seems
// unlikely that this bit pattern would show up there by
// coincidence.
int data = pid.pid + 99999;
try {
Convert.setIntValue(data, 0, pg.getpage());
} catch (IOException e) {
System.err.print("*** Convert value failed\n");
status = FAIL;
e.printStackTrace();
}
// Leave the page pinned if it equals 12 mod 20. This is a
// random number based loosely on a bug report.
if (status == OK) {
if (pid.pid % 20 != 12) {
try {
SystemDefs.JavabaseBM.unpinPage(pid, /*dirty:*/ true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin dirty page " + pid.pid + "\n");
}
}
}
}
}
if (status == OK) {
System.out.print(" - Read the pages\n");
for (index = 0; status == OK && index < numPages; ++index) {
pid = pids[index];
try {
SystemDefs.JavabaseBM.pinPage(pid, pg, false);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not pin page " + pid.pid + "\n");
e.printStackTrace();
}
if (status == OK) {
int data = 0;
try {
data = Convert.getIntValue(0, pg.getpage());
} catch (IOException e) {
System.err.print("*** Convert value failed \n");
status = FAIL;
}
if (data != pid.pid + 99999) {
status = FAIL;
System.err.print("*** Read wrong data back from page " + pid.pid + "\n");
}
}
if (status == OK) {
try {
SystemDefs.JavabaseBM.unpinPage(pid, true); // might not be dirty
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin page " + pid.pid + "\n");
e.printStackTrace();
}
}
if (status == OK && (pid.pid % 20 == 12)) {
try {
SystemDefs.JavabaseBM.unpinPage(pid, /*dirty:*/ true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin page " + pid.pid + "\n");
e.printStackTrace();
}
}
}
}
if (status == OK) System.out.print(" Test 3 completed successfully.\n");
return status;
}
/**
* overrides the test1 function in TestDriver. It tests some simple normal buffer manager
* operations.
*
* @return whether test1 has passed
*/
protected boolean test1() {
System.out.print("\n Test 1 does a simple test of normal buffer ");
System.out.print("manager operations:\n");
// We choose this number to ensure that at least one page will have to be
// written during this test.
boolean status = OK;
int numPages = SystemDefs.JavabaseBM.getNumUnpinnedBuffers() + 1;
Page pg = new Page();
PageId pid;
PageId lastPid;
PageId firstPid = new PageId();
System.out.print(" - Allocate a bunch of new pages\n");
try {
firstPid = SystemDefs.JavabaseBM.newPage(pg, numPages);
} catch (Exception e) {
System.err.print("*** Could not allocate " + numPages);
System.err.print(" new pages in the database.\n");
e.printStackTrace();
return false;
}
// Unpin that first page... to simplify our loop.
try {
SystemDefs.JavabaseBM.unpinPage(firstPid, false /*not dirty*/);
} catch (Exception e) {
System.err.print("*** Could not unpin the first new page.\n");
e.printStackTrace();
status = FAIL;
}
System.out.print(" - Write something on each one\n");
pid = new PageId();
lastPid = new PageId();
for (pid.pid = firstPid.pid, lastPid.pid = pid.pid + numPages;
status == OK && pid.pid < lastPid.pid;
pid.pid = pid.pid + 1) {
try {
SystemDefs.JavabaseBM.pinPage(pid, pg, /*emptyPage:*/ true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not pin new page " + pid.pid + "\n");
e.printStackTrace();
}
if (status == OK) {
// Copy the page number + 99999 onto each page. It seems
// unlikely that this bit pattern would show up there by
// coincidence.
int data = pid.pid + 99999;
try {
Convert.setIntValue(data, 0, pg.getpage());
} catch (IOException e) {
System.err.print("*** Convert value failed\n");
status = FAIL;
}
if (status == OK) {
try {
SystemDefs.JavabaseBM.unpinPage(pid, /*dirty:*/ true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin dirty page " + pid.pid + "\n");
e.printStackTrace();
}
}
}
}
if (status == OK)
System.out.print(
" - Read that something back from each one\n"
+ " (because we're buffering, this is where "
+ "most of the writes happen)\n");
for (pid.pid = firstPid.pid; status == OK && pid.pid < lastPid.pid; pid.pid = pid.pid + 1) {
try {
SystemDefs.JavabaseBM.pinPage(pid, pg, /*emptyPage:*/ false);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not pin page " + pid.pid + "\n");
e.printStackTrace();
}
if (status == OK) {
int data = 0;
try {
data = Convert.getIntValue(0, pg.getpage());
} catch (IOException e) {
System.err.print("*** Convert value failed \n");
status = FAIL;
}
if (status == OK) {
if (data != (pid.pid) + 99999) {
status = FAIL;
System.err.print("*** Read wrong data back from page " + pid.pid + "\n");
}
}
if (status == OK) {
try {
SystemDefs.JavabaseBM.unpinPage(pid, /*dirty:*/ true);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Could not unpin page " + pid.pid + "\n");
e.printStackTrace();
}
}
}
}
if (status == OK) System.out.print(" - Free the pages again\n");
for (pid.pid = firstPid.pid; pid.pid < lastPid.pid; pid.pid = pid.pid + 1) {
try {
SystemDefs.JavabaseBM.freePage(pid);
} catch (Exception e) {
status = FAIL;
System.err.print("*** Error freeing page " + pid.pid + "\n");
e.printStackTrace();
}
}
if (status == OK) System.out.print(" Test 1 completed successfully.\n");
return status;
}