// reads a resource or a reservation data item
protected virtual bool Read <I, R>(Transaction context, StorageContext storageContext, StorageIndex <I> index, I rID, bool lockPage, out R data)
{
// look for the resource in the index
IndexItem <I> address = index.GetResourceAddress(rID);
if (null == address)
{
data = default(R);
return(false);
}
if (lockPage)
{
// Aquire a lock on the logical page address to ensure that the page is not
// being written while we read the data
this.LockPage(context, MyLM.LockMode.Read, address.Page);
}
// find the physical page
int fileAddress = storageContext.PageTable.GetPhysicalPage(address.Page);
// get the page
StoragePage page = new StoragePage();
this.aReadPageData(page, fileAddress);
// read the data
data = (R)page.ReadRecord(address.Record);
return(true);
}
private DBHdr ReadDBRoot()
{
DBHdr dbRoot = null;
try
{
StoragePage rootPage = new StoragePage();
rootPage.ReadPageData(this.dataFile, RootPage);
dbRoot = (DBHdr)rootPage.ReadRecord(0);
}
catch (Exception)
{
dbRoot = null;
}
return(dbRoot);
}
private void ReadRecords(StoragePage page, TestData[] data)
{
foreach (TestData test in data)
{
try
{
string result = (string)page.ReadRecord(test.recordIdx);
Assert.AreEqual(test.data, result,
"Read record did not match. Test Data = [{0}]", test.ToString());
}
catch (Exception e)
{
Assert.AreEqual(test.exception, e.GetType().Name,
"Unexpected exception. Test Data = [{0}]", test.ToString());
}
}
}
