/// <summary>
/// Calculates the sequence in which files should be deleted based on their releations.
/// </summary>
/// <returns>The deletable volumes.</returns>
/// <param name="deleteableVolumes">Block volumes slated for deletion.</param>
public IEnumerable <IRemoteVolume> GetDeletableVolumes(IEnumerable <IRemoteVolume> deleteableVolumes, System.Data.IDbTransaction transaction)
{
using (var cmd = m_connection.CreateCommand())
{
// Although the generated index volumes are always in pairs,
// this code handles many-to-many relations between
// index files and block volumes, should this be added later
var lookupBlock = new Dictionary <string, List <IRemoteVolume> >();
var lookupIndexfiles = new Dictionary <string, List <string> >();
cmd.Transaction = transaction;
using (var rd = cmd.ExecuteReader(@"SELECT ""C"".""Name"", ""B"".""Name"", ""B"".""Hash"", ""B"".""Size"" FROM ""IndexBlockLink"" A, ""RemoteVolume"" B, ""RemoteVolume"" C WHERE ""A"".""IndexVolumeID"" = ""B"".""ID"" AND ""A"".""BlockVolumeID"" = ""C"".""ID"" AND ""B"".""Hash"" IS NOT NULL AND ""B"".""Size"" IS NOT NULL "))
while (rd.Read())
{
var name = rd.GetValue(0).ToString();
List <IRemoteVolume> indexfileList;
if (!lookupBlock.TryGetValue(name, out indexfileList))
{
indexfileList = new List <IRemoteVolume>();
lookupBlock.Add(name, indexfileList);
}
var v = new RemoteVolume(rd.GetString(1), rd.GetString(2), rd.GetInt64(3));
indexfileList.Add(v);
List <string> blockList;
if (!lookupIndexfiles.TryGetValue(v.Name, out blockList))
{
blockList = new List <string>();
lookupIndexfiles.Add(v.Name, blockList);
}
blockList.Add(name);
}
foreach (var r in deleteableVolumes.Distinct())
{
// Return the input
yield return(r);
List <IRemoteVolume> indexfileList;
if (lookupBlock.TryGetValue(r.Name, out indexfileList))
{
foreach (var sh in indexfileList)
{
List <string> backref;
if (lookupIndexfiles.TryGetValue(sh.Name, out backref))
{
//If this is the last reference,
// remove the index file as well
if (backref.Remove(r.Name) && backref.Count == 0)
{
yield return(sh);
}
}
}
}
}
}
}
/// <summary>
/// Calculates the sequence in which files should be deleted based on their releations.
/// </summary>
/// <returns>The deletable volumes.</returns>
/// <param name="deleteableVolumes">Block volumes slated for deletion.</param>
public IEnumerable<IRemoteVolume> GetDeletableVolumes(IEnumerable<IRemoteVolume> deleteableVolumes, System.Data.IDbTransaction transaction)
{
using(var cmd = m_connection.CreateCommand())
{
// Although the generated index volumes are always in pairs,
// this code handles many-to-many relations between
// index files and block volumes, should this be added later
var lookupBlock = new Dictionary<string, List<IRemoteVolume>>();
var lookupIndexfiles = new Dictionary<string, List<string>>();
cmd.Transaction = transaction;
using(var rd = cmd.ExecuteReader(@"SELECT ""C"".""Name"", ""B"".""Name"", ""B"".""Hash"", ""B"".""Size"" FROM ""IndexBlockLink"" A, ""RemoteVolume"" B, ""RemoteVolume"" C WHERE ""A"".""IndexVolumeID"" = ""B"".""ID"" AND ""A"".""BlockVolumeID"" = ""C"".""ID"" AND ""B"".""Hash"" IS NOT NULL AND ""B"".""Size"" IS NOT NULL "))
while(rd.Read())
{
var name = rd.GetValue(0).ToString();
List<IRemoteVolume> indexfileList;
if (!lookupBlock.TryGetValue(name, out indexfileList))
{
indexfileList = new List<IRemoteVolume>();
lookupBlock.Add(name, indexfileList);
}
var v = new RemoteVolume(rd.GetValue(1).ToString(), rd.GetValue(2).ToString(), Convert.ToInt64(rd.GetValue(3)));
indexfileList.Add(v);
List<string> blockList;
if (!lookupIndexfiles.TryGetValue(v.Name, out blockList))
{
blockList = new List<string>();
lookupIndexfiles.Add(v.Name, blockList);
}
blockList.Add(name);
}
foreach(var r in deleteableVolumes.Distinct())
{
// Return the input
yield return r;
List<IRemoteVolume> indexfileList;
if (lookupBlock.TryGetValue(r.Name, out indexfileList))
foreach(var sh in indexfileList)
{
List<string> backref;
if (lookupIndexfiles.TryGetValue(sh.Name, out backref))
{
//If this is the last reference,
// remove the index file as well
if (backref.Remove(r.Name) && backref.Count == 0)
yield return sh;
}
}
}
}
}