public void JetPrereadKeys()
{
if (!EsentVersion.SupportsWindows7Features)
{
return;
}
// We need enough records to force a vertical split. ESENT returns
// 0 for keysPreread when we have a single-level tree.
const int NumRecords = 128;
byte[][] keys = new byte[NumRecords][];
int[] keyLengths = new int[NumRecords];
Api.JetBeginTransaction(this.sesid);
// This table uses a sequential index so the records will
// be in key order.
for (int i = 0; i < NumRecords; ++i)
{
Api.JetPrepareUpdate(this.sesid, this.tableid, JET_prep.Insert);
this.SetColumnFromString(Any.StringOfLength(255));
this.UpdateAndGotoBookmark();
keys[i] = Api.RetrieveKey(this.sesid, this.tableid, RetrieveKeyGrbit.None);
keyLengths[i] = keys[i].Length;
}
Api.JetCommitTransaction(this.sesid, CommitTransactionGrbit.None);
int keysPreread;
Windows7Api.JetPrereadKeys(this.sesid, this.tableid, keys, keyLengths, NumRecords, out keysPreread, PrereadKeysGrbit.Forward);
Assert.AreNotEqual(0, keysPreread, "No keys were preread?!");
}
public void JetPrereadKeys()
{
if (!EsentVersion.SupportsWindows7Features)
{
return;
}
// We need enough records to force a vertical split. ESENT returns
// 0 for keysPreread when we have a single-level tree.
const int NumRecords = 1024;
byte[][] keys = new byte[NumRecords][];
int[] keyLengths = new int[NumRecords];
// Setting a fixed cache size improves reliability of this test case because,
// due to optimization reasons, we may drop pre-reads with a small cache size.
// But first, we'll set the cache to a very small value and only grow it later
// so that we know for sure we'll have available buffers.
int cacheSizeMinOriginal = SystemParameters.CacheSizeMin;
int cacheSizeMaxOriginal = SystemParameters.CacheSizeMax;
SystemParameters.CacheSizeMin = 128;
SystemParameters.CacheSizeMax = 128;
try
{
Api.JetBeginTransaction(this.sesid);
// This table uses a sequential index so the records will
// be in key order.
for (int i = 0; i < NumRecords; ++i)
{
Api.JetPrepareUpdate(this.sesid, this.tableid, JET_prep.Insert);
this.SetColumnFromString(Any.StringOfLength(1024));
this.UpdateAndGotoBookmark();
keys[i] = Api.RetrieveKey(this.sesid, this.tableid, RetrieveKeyGrbit.None);
keyLengths[i] = keys[i].Length;
}
Api.JetCommitTransaction(this.sesid, CommitTransactionGrbit.None);
SystemParameters.CacheSizeMin = 1024;
SystemParameters.CacheSizeMax = 1024;
int keysPreread;
Windows7Api.JetPrereadKeys(this.sesid, this.tableid, keys, keyLengths, NumRecords, out keysPreread, PrereadKeysGrbit.Forward);
Assert.AreNotEqual(0, keysPreread, "No keys were preread?!");
}
finally
{
SystemParameters.CacheSizeMin = cacheSizeMinOriginal;
SystemParameters.CacheSizeMax = cacheSizeMaxOriginal;
}
}
private void PrereadKeys()
{
Console.WriteLine("\tPrereadKeys");
JET_TABLEID tableid;
Api.JetOpenTable(this.sesid, this.dbid, this.table, null, 0, OpenTableGrbit.None, out tableid);
var keys = new byte[4][];
for (int i = 0; i < keys.Length; ++i)
{
Api.MakeKey(this.sesid, tableid, i, MakeKeyGrbit.NewKey);
keys[i] = Api.RetrieveKey(this.sesid, tableid, RetrieveKeyGrbit.RetrieveCopy);
}
int[] keyLengths = (from x in keys select x.Length).ToArray();
int ignored;
Windows7Api.JetPrereadKeys(
this.sesid, tableid, keys, keyLengths, keys.Length, out ignored, PrereadKeysGrbit.Forward);
Api.JetCloseTable(this.sesid, tableid);
}
public void VerifyXpThrowsExceptionOnJetPrereadKeys()
{
int ignored;
Windows7Api.JetPrereadKeys(JET_SESID.Nil, JET_TABLEID.Nil, null, null, 0, out ignored, PrereadKeysGrbit.Forward);
}