private static void Migrate(StorageEnvironment env, string tableName, Action <string> output, Action <Slice, RavenJObject> modifyRecord)
{
long entriesCount;
using (var tx = env.NewTransaction(TransactionFlags.ReadWrite))
{
entriesCount = tx.ReadTree(tableName).State.EntriesCount;
}
if (entriesCount == 0)
{
output(string.Format("No records to migrate in '{0}' table.", tableName));
return;
}
output(string.Format("Starting to migrate '{0}' table to. Records to process: {1}", tableName, entriesCount));
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
env.DeleteTree(txw, "Temp_" + tableName);
txw.Commit();
}
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
env.CreateTree(txw, "Temp_" + tableName);
txw.Commit();
}
var migrated = 0L;
var keyToSeek = Slice.BeforeAllKeys;
do
{
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
var destTree = txw.ReadTree("Temp_" + tableName);
var srcTree = txw.ReadTree(tableName);
var iterator = srcTree.Iterate();
if (iterator.Seek(keyToSeek) == false)
{
break;
}
var itemsInBatch = 0;
do
{
keyToSeek = iterator.CurrentKey;
if (itemsInBatch != 0 && itemsInBatch % 100 == 0)
{
break;
}
using (var stream = iterator.CreateReaderForCurrent().AsStream())
{
var value = stream.ToJObject();
modifyRecord(iterator.CurrentKey, value);
using (var streamValue = new MemoryStream())
{
value.WriteTo(streamValue);
streamValue.Position = 0;
destTree.Add(iterator.CurrentKey, streamValue);
}
migrated++;
itemsInBatch++;
}
} while (iterator.MoveNext());
txw.Commit();
output(string.Format("{0} of {1} entries processed.", migrated, entriesCount));
}
} while (migrated < entriesCount);
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
env.DeleteTree(txw, tableName);
env.RenameTree(txw, "Temp_" + tableName, tableName);
txw.Commit();
}
}
public void MigrateToStructures <T>(StorageEnvironment env, TableOfStructures <T> table, Action <string> output, Action <RavenJObject, Structure <T> > copyToStructure)
{
long entriesCount;
using (var tx = env.NewTransaction(TransactionFlags.ReadWrite))
{
entriesCount = tx.ReadTree(table.TableName).State.EntriesCount;
}
if (entriesCount == 0)
{
output(string.Format("No records to migrate in '{0}' table.", table.TableName));
return;
}
output(string.Format("Starting to migrate '{0}' table to use structures. Records to process: {1}", table.TableName, entriesCount));
var migratedEntries = 0L;
var keyToSeek = Slice.BeforeAllKeys;
// delete Temp_TabelName if exists
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
env.DeleteTree(txw, "Temp_" + table.TableName);
txw.Commit();
}
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
env.CreateTree(txw, "Temp_" + table.TableName);
txw.Commit();
}
do
{
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
var destTree = txw.ReadTree("Temp_" + table.TableName);
var srcTree = txw.ReadTree(table.TableName);
var iterator = srcTree.Iterate();
if (iterator.Seek(keyToSeek) == false)
{
break;
}
var writtenStructsSize = 0;
do
{
keyToSeek = iterator.CurrentKey;
if (writtenStructsSize > 8 * 1024 * 1024) // 8 MB
{
break;
}
var readerForCurrent = iterator.CreateReaderForCurrent();
using (var stream = readerForCurrent.AsStream())
{
var currentDataSize = iterator.GetCurrentDataSize();
try
{
RavenJObject jsonValue = stream.ToJObject();
var structValue = new Structure <T>(table.Schema);
copyToStructure(jsonValue, structValue);
destTree.WriteStruct(iterator.CurrentKey, structValue);
writtenStructsSize += structValue.GetSize();
}
catch (Exception)
{
// already converted this, probably, just move as is
int used;
var readBytes = readerForCurrent.ReadBytes(currentDataSize, out used);
destTree.Add(iterator.CurrentKey, readBytes);
writtenStructsSize += currentDataSize;
}
migratedEntries++;
}
} while (iterator.MoveNext());
txw.Commit();
output(string.Format("{0} of {1} records processed.", migratedEntries, entriesCount));
}
} while (migratedEntries < entriesCount);
using (var txw = env.NewTransaction(TransactionFlags.ReadWrite))
{
env.DeleteTree(txw, table.TableName);
env.RenameTree(txw, "Temp_" + table.TableName, table.TableName);
txw.Commit();
}
output(string.Format("All records of '{0}' table have been migrated to structures.", table.TableName));
}