public static IEnumerable <ManifestImmutable> ReadAllManifests(string baseFileName)
{
string manifestFile = Config.ManifestFile(baseFileName);
if (!File.Exists(manifestFile))
{
throw new FileNotFoundException("Could not find the manifest file.", manifestFile);
}
FileStream fs = new FileStream(manifestFile, FileMode.Open, FileAccess.Read, FileShare.None, 1024, false);
BinaryReader reader = new BinaryReader(fs);
try {
do
{
var m = new ManifestImmutable(null);
m.ReadManifestContents(reader);
yield return(m);
reader.ReadInt32(); // Consume the size encoded at the end of each manifest
} while (true);
} finally {
reader.Close();
}
}
void Read()
{
string manifestFile = Config.ManifestFile(_baseFileName);
if (!File.Exists(manifestFile))
{
_manifests.AddLast(new ManifestImmutable(this));
return;
}
FileStream fs = new FileStream(manifestFile, FileMode.Open, FileAccess.Read, FileShare.None, 1024, false);
BinaryReader reader = new BinaryReader(fs);
try {
// Get the size of the last manifest block
reader.BaseStream.Seek(-4, SeekOrigin.End);
int size = reader.ReadInt32();
// Now seek to that position and read it
reader.BaseStream.Seek(-size - 4, SeekOrigin.End);
var m = new ManifestImmutable(this);
m.ReadManifestContents(reader);
_manifests.AddLast(m);
} catch (Exception ex) {
LogMessage("Error reading manifest file: {0}", _baseFileName);
ex.GetBaseException();
} finally {
reader.Close();
}
}
void CommitManifest(ManifestImmutable manifest)
{
lock (manifestLock) {
Write(manifest);
_manifests.AddLast(manifest);
}
}
ManifestImmutable Clone()
{
// Clone this copy of the manifest.
var clone = new ManifestImmutable(_manifest);
for (int v = 0; v < _versions.Length; v++)
{
clone._versions [v] = _versions [v];
}
for (int p = 0; p < _pages.Length; p++)
{
clone._pages [p] = new List <PageRecord> ();
foreach (var page in _pages[p])
{
clone._pages [p].Add(page);
}
}
return(clone);
}
void Write(ManifestImmutable m)
{
// Get an in-memory copy of the all the bytes that will be written to the manifest
var ms = new MemoryStream();
var writer = new BinaryWriter(ms);
m.WriteManifestContents(writer);
writer.Close();
var manifestBytes = ms.ToArray();
// Increment manifest versions, we're getting ready to write another copy
_manifestVersion++;
_altManifestVersion++;
// Write primary manifest
FileMode fileMode = FileMode.Append;
if (_manifestVersion > Config.ManifestVersionCount)
{
fileMode = FileMode.Create;
_manifestVersion = 0;
}
using (FileStream mfs = new FileStream(Config.ManifestFile(BaseFileName), fileMode, FileAccess.Write, FileShare.None, 8, FileOptions.WriteThrough)) {
IAsyncResult manifestWrite = mfs.BeginWrite(manifestBytes, 0, manifestBytes.Length, null, null);
// Write alternative manifest
fileMode = FileMode.Append;
if (_altManifestVersion > Config.ManifestVersionCount)
{
fileMode = FileMode.Create;
_altManifestVersion = 0;
}
using (FileStream afs = new FileStream(Config.AltManifestFile(BaseFileName), fileMode, FileAccess.Write, FileShare.None, 8, FileOptions.WriteThrough)) {
IAsyncResult altManifestWrite = afs.BeginWrite(manifestBytes, 0, manifestBytes.Length, null, null);
// Wait for i/o's to complete
mfs.EndWrite(manifestWrite);
afs.EndWrite(altManifestWrite);
}
}
}
void ReleaseManifest(ManifestImmutable manifest)
{
lock (manifestLock)
_manifests.Remove(manifest);
}