private void prepareTransaction(EvalContext ctx)
{
var statements = ctx.Transaction.Statements;
for (var i = 0; i < statements.Length; i++)
{
var statement = statements[i];
statement.Prepare(ctx, i.ToString() + ":/");
}
}
private string getDescr(string descr, EvalContext ctx)
{
if (descr.IsNullOrWhiteSpace())
{
descr = ctx.Transaction.Description;
}
if (descr.IsNullOrWhiteSpace())
{
descr = ctx.SessionDescription;
}
return(descr);
}
//warning: this is called under the global lock on NS, do not block
private LockTransactionResult executeTransaction(EvalContext ctx, uint appRunTimeSec, double trustLevel)
{
var status = LockStatus.TransactionOK;
var errorCause = LockErrorCause.Unspecified;
var statements = ctx.Transaction.Statements;
for (var i = 0; i < statements.Length; i++)
{
var statement = statements[i];
statement.Execute(ctx);
if (ctx.Aborted)
{
status = LockStatus.TransactionError;
errorCause = LockErrorCause.Statement;
break;
}
}
//now Commit/Rollback all changes
if (status == LockStatus.TransactionOK)
{//commit
foreach (var tbl in ctx.Namespace.m_MutatedTables)
{
tbl.Commit(ctx.Session);
}
}
else
{//rollback
foreach (var tbl in ctx.Namespace.m_MutatedTables)
{
tbl.Rollback(ctx.Session);
}
}
ctx.Namespace.m_MutatedTables.Clear();
return(new LockTransactionResult(ctx.Transaction.ID,
App.AsSky().HostName,
status,
errorCause,
ctx.FailedStatement,
appRunTimeSec,//passed-in not to calculate under lock
trustLevel,
ctx.Data));
}
/// <summary>
/// Returns named variable value or value array created by this or another session.
/// If not found then null is returned
/// </summary>
public object GetVariable(bool many, EvalContext ctx, string name, bool ignoreThisSession)
{
DataSlot slot;
if (!m_Data.TryGetValue(name, out slot))
{
return(null);
}
var list = slot.Data;
if (list == null)
{
return(null);
}
if (many)
{
Variable[] result;
if (!ignoreThisSession)
{
result = list.ToArray();
}
else
{
result = list.Where(i => !i.SessionID.Equals(ctx.SessionID)).ToArray();
}
return(result.Length > 0 ? result : null);
}
//else Single
if (list.Count == 0)
{
return(null);
}
if (!ignoreThisSession)
{
return(list[0]);
}
return(list.FirstOrDefault(i => !i.SessionID.Equals(ctx.SessionID)));
}
/// <summary>
/// Returns true if named variable exists created by this or another session
/// </summary>
public bool Exists(EvalContext ctx, string name, object value, bool ignoreThisSession)
{
DataSlot slot;
if (!m_Data.TryGetValue(name, out slot))
{
return(false);
}
var list = slot.Data;
if (list == null)
{
return(false);
}
if (!ignoreThisSession)
{
if (value == null)
{
return(list.Count > 0);
}
return(list.Any(e => e.Value != null && value.Equals(e.Value)));
}
for (var i = 0; i < list.Count; i++)
{
var var = list[i];
if (!var.SessionID.Equals(ctx.SessionID))
{
if (value == null)
{
return(true);
}
if (var.Value != null && var.Value.Equals(value))
{
return(true);
}
}
}
return(false);
}
/// <summary>
/// Deletes named var, true if found and removed
/// </summary>
public bool DeleteVariable(EvalContext ctx, string name, object value)
{
DataSlot slot;
if (!m_Data.TryGetValue(name, out slot))
{
return(false);
}
var list = slot.Data;
if (list == null)
{
return(false);
}
var anymatch = list.Any(v => v.SessionID.Equals(ctx.SessionID) && (value == null || value.Equals(v.Value)));
if (!anymatch)
{
return(false);
}
VarList newList = new VarList();
for (var i = 0; i < list.Count; i++)
{
var var = list[i];
if (var.SessionID.Equals(ctx.SessionID) && (value == null || value.Equals(var.Value)))
{
continue;//skip what gets deleted
}
newList.Add(var);
}
slot.Change(newList);
m_PendingChanges.Add(slot);
m_Namespace.m_MutatedTables.Add(this);
return(true);
}
/// <summary>
/// Sets named var
/// </summary>
public bool SetVariable(EvalContext ctx, string name, object value, string description, DateTime?expirationTimeUTC, bool allowDuplicates)
{
DataSlot slot;
VarList list;
if (!m_Data.TryGetValue(name, out slot))
{
slot = new DataSlot();
list = new VarList();
var var = new Variable(ctx.SessionID,
ctx.Transaction.ID,
App.TimeSource.UTCNow,
expirationTimeUTC,
getDescr(description, ctx),
value);
list.Add(var);
slot.Change(list);
m_Data.Add(name, slot);
m_PendingChanges.Add(slot);
m_Namespace.m_MutatedTables.Add(this);
return(true);
}
list = slot.Data;
if (list == null)
{
list = new VarList();
var var = new Variable(ctx.SessionID,
ctx.Transaction.ID,
App.TimeSource.UTCNow,
expirationTimeUTC,
getDescr(description, ctx),
value);
list.Add(var);
slot.Change(list);
//20161102
//m_Data.Add(name, slot);
m_PendingChanges.Add(slot);
m_Namespace.m_MutatedTables.Add(this);
return(true);
}
if (list.Count > 0 && !allowDuplicates)
{
return(false);
}
var newList = new VarList(list);
var replaced = false;
for (var i = 0; i < newList.Count; i++)
{
var var = newList[i];
if (var.SessionID.Equals(ctx.SessionID))
{
var nvar = new Variable(ctx.SessionID,
ctx.Transaction.ID,
App.TimeSource.UTCNow,
expirationTimeUTC,
getDescr(description, ctx),
value);
newList[i] = nvar;
replaced = true;
break;
}
}
if (!replaced)
{
var nvar = new Variable(ctx.SessionID,
ctx.Transaction.ID,
App.TimeSource.UTCNow,
expirationTimeUTC,
getDescr(description, ctx),
value);
newList.Add(nvar);
}
slot.Change(newList);
m_PendingChanges.Add(slot);
m_Namespace.m_MutatedTables.Add(this);
return(true);
}
private LockTransactionResult executeLockTransaction(LockSessionData session, LockTransaction transaction)
{
if (!Running)
{
return(LockTransactionResult.CallFailed);
}
Interlocked.Increment(ref m_CurrentServerCalls);
if (session == null || transaction == null)
{
throw new LockingException(StringConsts.ARGUMENT_ERROR + GetType().Name + ".ExecuteLockTransaction(session|transaction==null)");
}
var isPing = transaction.Statements == null;
if (!isPing && transaction.Namespace.IsNullOrWhiteSpace())
{
throw new LockingException(StringConsts.ARGUMENT_ERROR + GetType().Name + ".ExecuteLockTransaction(transaction.Namespace==null|empty)");
}
var sapp = App.AsSky();
var currentTrustLevel = CurrentTrustLevel;
var appRunTimeSec = (uint)(DateTime.UtcNow - m_StartTimeUTC).TotalSeconds;
//insufficient runtime period length or trust level
if (transaction.MinimumRequiredRuntimeSec > appRunTimeSec ||
transaction.MinimumRequiredTrustLevel > currentTrustLevel)
{
return(new LockTransactionResult(transaction.ID,
sapp.HostName,
LockStatus.TransactionError,
LockErrorCause.MinimumRequirements,
null,
appRunTimeSec,
currentTrustLevel,
null));
}
var sid = session.ID.ToString();
var ss = m_Sessions.GetOrRegister(sid, (sd) => new ServerLockSession(sd), session);
lock (ss)
{
if (ss.Disposed)
{
return(new LockTransactionResult(transaction.ID,
sapp.HostName,
LockStatus.TransactionError,
LockErrorCause.SessionExpired,
null,
appRunTimeSec,
currentTrustLevel,
null));
}
ss.m_LastInteractionUTC = App.TimeSource.UTCNow;
if (isPing)//ping just touches session above
{
return(new LockTransactionResult(transaction.ID,
sapp.HostName,
LockStatus.TransactionOK,
LockErrorCause.Unspecified,
null,
appRunTimeSec,
currentTrustLevel,
null));
}
var ns = m_Namespaces.GetOrRegister <object>(transaction.Namespace, (_) => new Namespace(App, transaction.Namespace), null);
var ectx = new EvalContext(ss, ns, transaction);
prepareTransaction(ectx); //prepare is not under the lock
LockTransactionResult result;
lock (ns) //execute is UNDER THE LOCK
result = executeTransaction(ectx, appRunTimeSec, currentTrustLevel);
return(result);
}
}