public static void sqlite3ConnectionBlocked(sqlite3b x, sqlite3b y)
{
}
// was:sqlite3BtreeBeginTrans
public RC BeginTrans(byte wrflag)
{
var shared = this.Shared;
var rc = RC.OK;
sqlite3BtreeEnter();
btreeIntegrity();
// If the btree is already in a write-transaction, or it is already in a read-transaction and a read-transaction is requested, this is a no-op.
if (this.InTransaction == TRANS.WRITE || (this.InTransaction == TRANS.READ && wrflag == 0))
goto trans_begun;
// Write transactions are not possible on a read-only database
if (shared.ReadOnly && wrflag != 0)
{
rc = RC.READONLY;
goto trans_begun;
}
#if !SQLITE_OMIT_SHARED_CACHE
// If another database handle has already opened a write transaction on this shared-btree structure and a second write transaction is
// requested, return SQLITE_LOCKED.
sqlite3b sharedDB = null;
if ((wrflag != 0 && shared.InTransaction == TRANS.WRITE) || shared.IsPending)
sharedDB = shared.Writer.DB;
else if (wrflag > 1)
for (var @lock = shared.Locks; @lock != null; @lock = @lock.Next)
if (@lock.Tree != this)
{
sharedDB = @lock.Tree.DB;
break;
}
if (sharedDB != null)
{
sqlite3b.sqlite3ConnectionBlocked(this.DB, sharedDB);
rc = RC.LOCKED_SHAREDCACHE;
goto trans_begun;
}
#endif
// Any read-only or read-write transaction implies a read-lock on page 1. So if some other shared-cache client already has a write-lock
// on page 1, the transaction cannot be opened. */
rc = querySharedCacheTableLock(MASTER_ROOT, LOCK.READ);
if (rc != RC.OK)
goto trans_begun;
shared.InitiallyEmpty = shared.Pages == 0;
do
{
// Call lockBtree() until either pBt.pPage1 is populated or lockBtree() returns something other than SQLITE_OK. lockBtree()
// may return SQLITE_OK but leave pBt.pPage1 set to 0 if after reading page 1 it discovers that the page-size of the database
// file is not pBt.pageSize. In this case lockBtree() will update pBt.pageSize to the page-size of the file on disk.
while (shared.Page1 == null && (rc = shared.lockBtree()) == RC.OK) ;
if (rc == RC.OK && wrflag != 0)
{
if (shared.ReadOnly)
rc = RC.READONLY;
else
{
rc = shared.Pager.Begin(wrflag > 1, this.DB.sqlite3TempInMemory());
if (rc == RC.OK)
rc = shared.newDatabase();
}
}
if (rc != RC.OK)
shared.unlockBtreeIfUnused();
} while (((int)rc & 0xFF) == (int)RC.BUSY && shared.InTransaction == TRANS.NONE && btreeInvokeBusyHandler(shared) != 0);
if (rc == RC.OK)
{
if (this.InTransaction == TRANS.NONE)
{
shared.Transactions++;
#if !SQLITE_OMIT_SHARED_CACHE
if (Sharable)
{
Debug.Assert(Locks.Tree == this && Locks.TableID == 1);
Locks.Lock = LOCK.READ;
Locks.Next = shared.Locks;
shared.Locks = Locks;
}
#endif
}
this.InTransaction = (wrflag != 0 ? TRANS.WRITE : TRANS.READ);
if (this.InTransaction > shared.InTransaction)
shared.InTransaction = this.InTransaction;
if (wrflag != 0)
{
var pPage1 = shared.Page1;
#if !SQLITE_OMIT_SHARED_CACHE
Debug.Assert(shared.Writer == null);
shared.Writer = this;
shared.IsExclusive = (wrflag > 1);
#endif
// If the db-size header field is incorrect (as it may be if an old client has been writing the database file), update it now. Doing
// this sooner rather than later means the database size can safely re-read the database size from page 1 if a savepoint or transaction
// rollback occurs within the transaction.
if (shared.Pages != ConvertEx.Get4(pPage1.Data, 28))
{
rc = Pager.Write(pPage1.DbPage);
if (rc == RC.OK)
ConvertEx.Put4(pPage1.Data, 28, shared.Pages);
}
}
}
trans_begun:
if (rc == RC.OK && wrflag != 0)
// This call makes sure that the pager has the correct number of open savepoints. If the second parameter is greater than 0 and
// the sub-journal is not already open, then it will be opened here.
rc = shared.Pager.OpenSavepoint(this.DB.nSavepoint);
btreeIntegrity();
sqlite3BtreeLeave();
return rc;
}
public static void sqlite3ConnectionBlocked(sqlite3b x, sqlite3b y)
{
}
internal static bool sqlite3SchemaMutexHeld(sqlite3b x, int y, ISchema z)
{
return(true);
}
internal static bool sqlite3BtreeHoldsAllMutexes(sqlite3b x)
{
return(true);
}
internal static bool sqlite3SchemaMutexHeld(sqlite3b x, int y, ISchema z)
{
return true;
}
internal static bool sqlite3BtreeHoldsAllMutexes(sqlite3b x)
{
return true;
}
