using System; using System.Collections.Generic; using System.Linq; using System.Text; using FLocal.Core; using FLocal.Core.DB; namespace FLocal.Common.actions { /// /// Note that you should create ChangeSet instances outside of transactions they're using! /// Otherwise, there will be a 100% DB deadlock in Dispose (or data in registry won't update) /// internal class ChangeSet : IDisposable { private static readonly object tablesLockOrder_locker = new object(); private static IEnumerable tablesLockOrder { get { return Cache>.instance.get( tablesLockOrder_locker, () => new List() { dataobjects.Thread.TableSpec.TABLE, //thread should come first because of Board.newThread locking order with two changesets dataobjects.Board.TableSpec.TABLE, dataobjects.Post.TableSpec.TABLE, dataobjects.Revision.TableSpec.TABLE, dataobjects.Account.TableSpec.TABLE, dataobjects.User.TableSpec.TABLE, dataobjects.AccountSettings.TableSpec.TABLE, dataobjects.AccountIndicator.TableSpec.TABLE, dataobjects.PMConversation.TableSpec.TABLE, dataobjects.PMMessage.TableSpec.TABLE, dataobjects.Thread.ReadMarkerTableSpec.TABLE, dataobjects.Board.ReadMarkerTableSpec.TABLE, dataobjects.Poll.TableSpec.TABLE, dataobjects.Poll.Vote.TableSpec.TABLE, dataobjects.Invite.TableSpec.TABLE, dataobjects.Moderator.TableSpec.TABLE, dataobjects.Punishment.TableSpec.TABLE, dataobjects.Session.TableSpec.TABLE, } ); } } private object locker = new object(); private bool isAdding; private bool isProcessing; private bool isProcessed; private Dictionary> changesByTable; public ChangeSet() { this.isAdding = false; this.isProcessing = false; this.isProcessed = false; this.changesByTable = new Dictionary>(); foreach(string table in tablesLockOrder) { this.changesByTable[table] = new HashSet(); } } public void Add(AbstractChange change) { lock(locker) { if(this.isAdding) throw new CriticalException("Cannot add inside add"); if(this.isProcessing || this.isProcessed) throw new CriticalException("ChangeSet is readonly"); this.isAdding = true; } if(!this.changesByTable.ContainsKey(change.tableSpec.name)) throw new CriticalException("Table not supported"); this.changesByTable[change.tableSpec.name].Add(change); this.isAdding = false; foreach(AbstractChange referencedChange in change.references) { this.Add(referencedChange); } } private void ApplyToChange(Transaction transaction, AbstractChange change) { foreach(AbstractChange referenced in change.references) { if(!referenced.getId().HasValue) { this.ApplyToChange(transaction, referenced); } } change.Apply(transaction); } public void Apply(Transaction transaction) { lock(this.locker) { if(this.isAdding) throw new CriticalException("Cannot process while adding"); if(this.isProcessing || this.isProcessed) throw new CriticalException("ChangeSet is already processed"); this.isProcessing = true; } foreach(string table in tablesLockOrder) { foreach(AbstractChange change in (from AbstractChange _change in this.changesByTable[table] orderby _change.getId() select _change)) { change.Lock(transaction); } } foreach(KeyValuePair> kvp in this.changesByTable) { foreach(AbstractChange change in kvp.Value) { this.ApplyToChange(transaction, change); } } this.isProcessed = true; } public void Dispose() { //if(!this.isProcessed) throw new CriticalException("ChangeSet is not processed yet"); if(this.isProcessed) { foreach(KeyValuePair> kvp in this.changesByTable) { foreach(AbstractChange change in kvp.Value) { if(change.getId().HasValue) { try { change.tableSpec.refreshSqlObject(change.getId().Value); } catch(NotFoundInDBException) { //it seems something broken earlier; transaction rollback etc... } } //otherwise we're disposing because of sql error or something, so we should show real cause of problem, not "id is null" } } } } } }