public DbIndex GetIndex(string columnName)
{
CheckColumnNameValid(columnName);
StringDictionary p = TableProperties;
long columnId = p.GetValue(columnName + ".id", -1);
if (columnId == -1)
{
throw new ApplicationException("Column '" + columnName + "' not found");
}
if (!p.GetValue(columnName + ".index", false))
{
throw new ApplicationException("Column '" + columnName + "' is not indexed");
}
// Fetch the index object,
IDataFile df = GetDataFile(GetIndexIdKey(columnId));
SortedIndex list = new SortedIndex(df);
// And return it,
IIndexedObjectComparer <string> comparer = GetIndexComparerFor(columnName, columnId);
return(new DbIndex(this, currentVersion, comparer, columnId, list));
}
public void Update(DbRow row)
{
if (rowBufferId != 0)
{
throw new ApplicationException("State error: previous table operation not completed");
}
// Check row is currently indexed,
long rowid = row.RowId;
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex rows = new SortedIndex(df);
if (!rows.ContainsSortKey(rowid))
{
throw new ApplicationException("Row being updated is not in the table");
}
if (rowBuffer == null)
{
rowBuffer = new Dictionary <string, string>();
}
rowBufferId = rowid;
// Copy from the existing data in the row,
string[] cols = ColumnNames;
foreach (string col in cols)
{
string val = row.GetValue(col);
if (val != null)
{
rowBuffer[col] = val;
}
}
}
public Key RemoveItem(String name)
{
++directoryVersion;
StringDictionary pset = new StringDictionary(GetDataFile(propertySetKey));
long id = pset.GetValue <long>(name, -1);
// Assert the item is stored,
if (id == -1)
{
throw new ApplicationException("Item not found: " + name);
}
pset.SetValue(name, null);
SortedIndex iset = new SortedIndex(GetDataFile(indexSetKey));
iset.Remove(name, id, collator);
// Delete the associated datafile
Key k = GetItemKey(id);
IDataFile df = GetDataFile(k);
df.Delete();
return(k);
}
public DbRowCursor GetReverseCursor()
{
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex list = new SortedIndex(df);
return(new DbRowCursor(this, currentVersion, new DbIndex.ReverseCursor(list.GetCursor())));
}
public Key AddItem(string name)
{
++directoryVersion;
StringDictionary pset = new StringDictionary(GetDataFile(propertySetKey));
// Assert the item isn't already stored,
if (pset.GetValue <long>(name, -1) != -1)
{
throw new ApplicationException("Item already exists: " + name);
}
// Generate a unique identifier for the name,
long id = GenerateId();
pset.SetValue(name, id);
SortedIndex iset = new SortedIndex(GetDataFile(indexSetKey));
iset.Insert(name, id, collator);
Key itemKey = GetItemKey(id);
IDataFile df = GetDataFile(itemKey);
try {
BinaryWriter dout = new BinaryWriter(new DataFileStream(df), Encoding.Unicode);
dout.Write(name);
} catch (IOException e) {
throw new ApplicationException(e.Message);
}
return(itemKey);
}
public int Delete(IEnumerator <DbRow> rows)
{
int deleteCount = 0;
while (rows.MoveNext())
{
DbRow row = rows.Current;
if (row == null)
{
continue;
}
long rowid = row.RowId;
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex rowsIndex = new SortedIndex(df);
if (rowsIndex.ContainsSortKey(rowid))
{
// Remove the row from the main index,
RemoveRowFromRowSet(rowid);
// Remove the row from any indexes defined on the table,
RemoveRowFromIndexSet(rowid);
// Delete the row file
IDataFile rowFile = GetDataFile(GetRowIdKey(rowid));
rowFile.Delete();
// Add this event to the transaction log,
AddTransactionEvent("deleteRow", rowid);
deleteCount++;
}
}
++currentVersion;
return(deleteCount);
}
private void RemoveRowFromRowSet(long rowid)
{
// Get the index object
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex rows = new SortedIndex(df);
// Remove the row in rowid value sorted order
rows.RemoveSortKey(rowid);
}
private void AddRowToRowSet(long rowid)
{
// Get the index object
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex rows = new SortedIndex(df);
// Add the row in rowid value sorted order
rows.InsertSortKey(rowid);
}
private void AddRowToIndexSet(long rowid)
{
// Get the set of columns that are indexed in this table,
string[] indexedCols = IndexedColumns;
foreach (String col in indexedCols)
{
// Resolve the column name to an id, turn it into a OrderedList64Bit,
// and insert the row in the correct location in the index,
long columnid = GetColumnId(col);
IDataFile df = GetDataFile(GetIndexIdKey(columnid));
SortedIndex index = new SortedIndex(df);
IIndexedObjectComparer <string> indexComparer = GetIndexComparerFor(col, columnid);
index.Insert(GetValue(rowid, columnid), rowid, indexComparer);
}
}
public void CheckTableDataDelete(String table, long rowid)
{
// Is it in the modification set?
if (tableDataChanged != null)
{
DbTable t;
if (tableDataChanged.TryGetValue(table, out t))
{
// Yes, so check if the given row in the modification set,
SortedIndex deleteSet = t.Deletes;
if (deleteSet.ContainsSortKey(rowid))
{
// Yes, so generate a commit fault,
throw new CommitFaultException(String.Format("Row in Table ''{0}'' was modified by a concurrent transaction",
table));
}
}
}
}
private void BuildIndex(long columnid, IIndexedObjectComparer <string> indexComparer)
{
// Get the index object
IDataFile df = GetDataFile(GetIndexIdKey(columnid));
// Get the index and clear it,
SortedIndex index = new SortedIndex(df);
index.Clear();
// For each row in this table,
foreach (DbRow row in this)
{
// Get the column value and the rowid
string columnValue = row.GetValue(columnid);
long rowid = row.RowId;
// Add it into the index,
index.Insert(columnValue, rowid, indexComparer);
}
// Done.
}
public void BeginUpdate(long rowid)
{
if (rowBufferId != 0)
{
throw new ApplicationException("State error: previous table operation not completed");
}
// Check row is currently indexed,
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex rows = new SortedIndex(df);
if (!rows.ContainsSortKey(rowid))
{
throw new ApplicationException("Row being updated is not in the table");
}
if (rowBuffer == null)
{
rowBuffer = new Dictionary <string, string>();
}
rowBufferId = rowid;
}
internal void PrepareForCommit()
{
// Write the transaction log for this table,
IDataFile df = GetDataFile(AddLog);
df.Delete();
SortedIndex addlist = new SortedIndex(df);
foreach (long v in addRowList)
{
addlist.InsertSortKey(v);
}
df = GetDataFile(RemoveLog);
df.Delete();
SortedIndex deletelist = new SortedIndex(df);
foreach (long v in deleteRowList)
{
if (addlist.ContainsSortKey(v))
{
addlist.RemoveSortKey(v);
}
else
{
deletelist.InsertSortKey(v);
}
}
// Set the id gen key
if (currentIdGen != -1)
{
StringDictionary p = TableProperties;
p.SetValue("k", currentIdGen);
}
}
public void Delete(DbRow row)
{
long rowid = row.RowId;
IDataFile df = GetDataFile(rowIndexKey);
SortedIndex rows = new SortedIndex(df);
if (!rows.ContainsSortKey(rowid))
{
throw new ApplicationException("Row being deleted is not in the table");
}
// Remove the row from the main index,
RemoveRowFromRowSet(rowid);
// Remove the row from any indexes defined on the table,
RemoveRowFromIndexSet(rowid);
// Delete the row file
IDataFile rowFile = GetDataFile(GetRowIdKey(rowid));
rowFile.Delete();
// Add this event to the transaction log,
AddTransactionEvent("deleteRow", rowid);
++currentVersion;
}
public DataAddress Commit(IPathConnection connection, DataAddress rootNode)
{
// Turn the proposal into a proposed_transaction,
ITransaction t = connection.CreateTransaction(rootNode);
DbTransaction proposedTransaction = new DbTransaction(null, rootNode, t);
try {
// Fetch the base root from the proposed_transaction log,
TextReader reader = proposedTransaction.GetLogReader();
string baseRootStr = reader.ReadLine();
// If 'base_root_str' is "no base root" then it means we are commiting
// an introduced transaction that is not an iteration of previous
// snapshots.
if (baseRootStr.Equals("no base root"))
{
// In which case, we publish the proposed snapshot unconditionally
// and return.
connection.Publish(rootNode);
return(rootNode);
}
DataAddress baseRoot = DataAddress.Parse(baseRootStr);
// Find all the entries since this base
DataAddress[] roots = connection.GetSnapshots(baseRoot);
// If there are no roots, we can publish the proposed_transaction
// unconditionally
if (roots.Length == 0)
{
connection.Publish(rootNode);
return(rootNode);
}
// Check historical log for clashes, and if none, replay the commands
// in the log.
// For each previous root, we build a structure that can answer the
// following questions;
// * Is file [name] created, deleted or changed in this root?
// * Is table [name] created or deleted in this root?
// * Is table [name] structurally changed in this root?
// * Has row [rowid] been deleted in table [name] in this root?
RootEvents[] rootEventSet = new RootEvents[roots.Length];
int i = 0;
// TODO: RootEvents is pre-computed information which we could
// store in a local cache for some speed improvements, so we don't
// need to walk through through the same data multiple times.
foreach (DataAddress root in roots)
{
RootEvents rootEvents = new RootEvents();
rootEventSet[i] = rootEvents;
++i;
// Create a transaction object for this root
ITransaction rootT = connection.CreateTransaction(root);
DbTransaction rootTransaction = new DbTransaction(null, root, rootT);
// Make a reader object for the log,
TextReader rootReader = rootTransaction.GetLogReader();
// Read the base root from this transaction,
String baseRootParent = rootReader.ReadLine();
// If 'bast_root_parent' is 'no base root' then it means a version
// has been introduced that is not an iteration of previous
// snapshots. In this case, it is not possible to merge updates
// therefore we generate a commit fault.
if (baseRootParent.Equals("no base root"))
{
throw new CommitFaultException("Transaction history contains introduced version.");
}
// Go through each log entry and determine if there's a clash,
string rootLine = rootReader.ReadLine();
while (rootLine != null)
{
String mfile = rootLine.Substring(2);
// This represents a file modification,
bool unknownCommand = false;
if (rootLine.StartsWith("F"))
{
rootEvents.SetFileChange(mfile);
}
// This is a table modification,
else if (rootLine.StartsWith("T"))
{
char c = rootLine[1];
// If this is a table create or delete event,
if (c == 'C' || c == 'D')
{
rootEvents.SetTableCreateOrDelete(mfile);
}
// This is a table structural change,
else if (c == 'S')
{
rootEvents.SetTableStructuralChange(mfile);
}
// This is a table data change event,
else if (c == 'M')
{
DbTable table = rootTransaction.GetTable(mfile);
rootEvents.SetTableDataChange(mfile, table);
}
else
{
unknownCommand = true;
}
}
else
{
unknownCommand = true;
}
if (unknownCommand)
{
throw new ApplicationException("Unknown transaction command: " + rootLine);
}
// Read the next log entry,
rootLine = rootReader.ReadLine();
}
}
// Now we have a set of RootEvents objects that describe what
// happens in each previous root.
// Now replay the events in the proposal transaction in the latest
// transaction.
// A transaction representing the current state,
DataAddress currentRoot = connection.GetSnapshot();
ITransaction currentT = connection.CreateTransaction(currentRoot);
DbTransaction currentTransaction = new DbTransaction(null, currentRoot, currentT);
String entry = reader.ReadLine();
while (entry != null)
{
String mfile = entry.Substring(2);
// If it's a file entry, we need to check the file hasn't been
// changed in any way in any roots
if (entry.StartsWith("F"))
{
foreach (RootEvents events in rootEventSet)
{
events.CheckFileChange(mfile);
}
// All checks passed, so perform the operation
currentTransaction.ReplayFileLogEntry(entry, proposedTransaction);
}
// If it's a table entry,
else if (entry.StartsWith("T"))
{
// Check that a table with this name hasn't been created, deleted
// or modified,
foreach (RootEvents events in rootEventSet)
{
// This fails on any event on this table, except a data change
// (insert or delete)
events.CheckTableMetaChange(mfile);
}
// The type of operation,
char c = entry[1];
// Is it a table structural change?
if (c == 'S')
{
// A structural change can only happen if all the roots leave the
// table untouched,
foreach (RootEvents events in rootEventSet)
{
// This fails if it finds a delete event for this rowid
events.CheckTableDataChange(mfile);
}
}
// Is it a table modification command?
else if (c == 'M')
{
// This is a table modification, we need to check the rowid
// logs and look for possible clashes,
// The delete set from the proposed transaction,
DbTable proposedTable = proposedTransaction.GetTable(mfile);
SortedIndex deleteSet = proposedTable.Deletes;
IIndexCursor dsi = deleteSet.GetCursor();
while (dsi.MoveNext())
{
long rowid = dsi.Current;
foreach (RootEvents events in rootEventSet)
{
// This fails if it finds a delete event for this rowid
events.CheckTableDataDelete(mfile, rowid);
}
}
}
// Go through each root, if the data in the table was changed
// by any of the roots, we set 'has_data_changes' to true;
bool hasDataChanges = false;
foreach (RootEvents events in rootEventSet)
{
if (events.HasTableDataChanges(mfile))
{
hasDataChanges = true;
}
}
// Ok, checks passed, so reply all the data changes on the table
currentTransaction.ReplayTableLogEntry(entry, proposedTransaction, hasDataChanges);
}
else
{
throw new ApplicationException("Unknown transaction command: " + entry);
}
// Read the next log entry,
entry = reader.ReadLine();
}
// Refresh the transaction log
currentTransaction.RefreshTransactionLog();
// Flush and publish the change
DataAddress finalRoot = connection.CommitTransaction(currentT);
connection.Publish(finalRoot);
// Done.
return(finalRoot);
} catch (IOException e) {
throw new ApplicationException("IO Error: " + e.Message);
}
}
public ItemList(Directory directory, SortedIndex sortedIndex)
{
this.directory = directory;
this.sortedIndex = sortedIndex;
localDirVersion = directory.directoryVersion;
}
internal void MergeFrom(DbTable from, bool structuralChange, bool historicDataChange)
{
// If structural_change is true, this can only happen if 'from' is the
// immediate child of this table.
// If 'historic_data_change' is false, this can only happen if 'from' is
// the immediate child of this table.
// Handle structural change,
if (structuralChange || historicDataChange == false)
{
// Fetch all the indexes,
string[] fromIndexes = from.IndexedColumns;
List <long> fromIndexIds = new List <long>(fromIndexes.Length);
foreach (String findex in fromIndexes)
{
fromIndexIds.Add(from.GetColumnId(findex));
}
// Copy them into here,
CopyFile(from.GetDataFile(from.rowIndexKey), GetDataFile(rowIndexKey));
foreach (long indexId in fromIndexIds)
{
// Copy all the indexes here,
CopyFile(from.GetDataFile(from.GetIndexIdKey(indexId)), GetDataFile(GetIndexIdKey(indexId)));
}
// Move the column and index information into this table,
CopyFile(from.propertiesFile, propertiesFile);
// Copy the transaction logs
CopyFile(from.GetDataFile(from.AddLog), GetDataFile(AddLog));
CopyFile(from.GetDataFile(from.RemoveLog), GetDataFile(RemoveLog));
// Replay the add and remove transaction events
SortedIndex addEvents = new SortedIndex(from.GetDataFile(from.AddLog));
SortedIndex removeEvents = new SortedIndex(from.GetDataFile(from.RemoveLog));
// Adds
foreach (long rowid in addEvents)
{
CopyFile(from.GetDataFile(from.GetRowIdKey(rowid)), GetDataFile(GetRowIdKey(rowid)));
}
// Removes
foreach (long rowid in removeEvents)
{
// Delete the row data file,
GetDataFile(GetRowIdKey(rowid)).Delete();
}
}
else
{
// If we are here, then we are merging a change that isn't a structural
// change, and there are historical changes. Basically this means we
// need to replay the add and remove events only, but more strictly,
// Replay the add and remove transaction events
SortedIndex addEvents = new SortedIndex(from.GetDataFile(from.AddLog));
SortedIndex removeEvents = new SortedIndex(from.GetDataFile(from.RemoveLog));
// Adds
foreach (long fromRowid in addEvents)
{
// Generate a new id for the row,
long toRowid = GenerateId();
// Copy record to the new id in this table,
CopyFile(from.GetDataFile(from.GetRowIdKey(fromRowid)), GetDataFile(GetRowIdKey(toRowid)));
// Update indexes,
AddRowToRowSet(toRowid);
AddRowToIndexSet(toRowid);
// Add this event to the transaction log,
AddTransactionEvent("insertRow", toRowid);
}
// Removes
foreach (long fromRowid in removeEvents)
{
// Update indexes,
RemoveRowFromRowSet(fromRowid);
RemoveRowFromIndexSet(fromRowid);
// Delete the row data file,
GetDataFile(GetRowIdKey(fromRowid)).Delete();
// Add this event to the transaction log,
AddTransactionEvent("deleteRow", fromRowid);
}
// Write out the transaction logs,
PrepareForCommit();
}
// Invalidate all the cached info,
columnIdMap = null;
cachedColumnList = null;
cachedIndexList = null;
++currentVersion;
}
public Cursor(SortedIndex index, long start, long end)
{
this.index = index;
this.end = end;
this.start = start;
}
