private void RollForwardRecover()
{
// The list of all journal files,
var journalFilesList = new List <JournalSummary>();
// Scan the journal path for any journal files.
for (int i = 10; i < 74; ++i)
{
string journalFn = GetJournalFileName(i);
string f = FileSystem.CombinePath(JournalPath, journalFn);
// If the journal exists, create a summary of the journal
if (FileSystem.FileExists(f))
{
if (ReadOnly)
{
throw new IOException(
"Journal file " + f + " exists for a read-only session. " +
"There may not be any pending journals for a Read-only session.");
}
var jf = new JournalFile(this, FileSystem, f, ReadOnly);
// Open the journal file for recovery. This will set various
// information about the journal such as the last check point and the
// id of the journal file.
JournalSummary summary = jf.OpenForRecovery();
// If the journal can be recovered from.
if (summary.CanBeRecovered)
{
Context.OnInformation(String.Format("Journal '{0}' found: can be recovered", jf));
journalFilesList.Add(summary);
}
else
{
Context.OnInformation(String.Format("Deleting journal '{0}': nothing to recover", jf));
// Otherwise close and delete it
jf.CloseAndDelete();
}
}
}
// Sort the journal file list from oldest to newest. The oldest journals
// are recovered first.
journalFilesList.Sort(new JournalSummaryComparer());
long lastJournalNumber = -1;
// Persist the journals
for (int i = 0; i < journalFilesList.Count; ++i)
{
var summary = journalFilesList[i];
// Check the resources for this summary
var resList = summary.Resources;
foreach (string resourceName in resList)
{
// This puts the resource into the hash map.
CreateResource(resourceName);
}
// Assert that we are recovering the journals input the correct order
JournalFile jf = summary.JournalFile;
if (jf.JournalNumber < lastJournalNumber)
{
throw new InvalidOperationException("Assertion failed, sort failed.");
}
lastJournalNumber = jf.JournalNumber;
Context.OnInformation(String.Format("Recovering '{0}' (8 .. {1})", jf, summary.LastCheckPoint));
jf.Persist(8, summary.LastCheckPoint);
// Then close and delete.
jf.CloseAndDelete();
// Check the resources for this summary and close them
foreach (var resourceName in resList)
{
var resource = (ResourceBase)CreateResource(resourceName);
// When we finished, make sure the resource is closed again
// Close the resource
resource.PersistClose();
// Post recover notification
resource.OnPostRecover();
}
}
}
internal JournalSummary OpenForRecovery()
{
if (IsOpen)
throw new IOException(String.Format("Journal file '{0}' is already open.", FilePath));
if (!FileSystem.FileExists(FilePath))
throw new IOException(String.Format("Journal file '{0}' does not exists.", FilePath));
// Open the random access file to this journal
File = new StreamFile(FileSystem, FilePath, ReadOnly);
IsOpen = true;
// Create the summary object (by default, not recoverable).
var summary = new JournalSummary(this);
long endPointer = File.Length;
// If end_pointer < 8 then can't recover this journal
if (endPointer < 8) {
return summary;
}
// The input stream.
using (var reader = new BinaryReader(File.FileStream, Encoding.Unicode)) {
// Set the journal number for this
JournalNumber = reader.ReadInt64();
long position = 8;
var checkpointResList = new List<string>();
// Start scan
while (true) {
// If we can't Read 12 bytes ahead, return the summary
if (position + 12 > endPointer) {
return summary;
}
long type = reader.ReadInt64();
int size = reader.ReadInt32();
position = position + size + 12;
bool skipBody = true;
// If checkpoint reached then we are recoverable
if (type == 100) {
summary.LastCheckPoint = position;
summary.CanBeRecovered = true;
// Add the resources input this check point
foreach (var checkpoint in checkpointResList) {
summary.Resources.Add(checkpoint);
}
// And clear the temporary list.
checkpointResList.Clear();
}
// If end reached, or type is not understood then return
else if (position >= endPointer ||
type < 1 || type > 7) {
return summary;
}
// If we are resource type, then load the resource
if (type == 2) {
// We don't skip body for this type, we Read the content
skipBody = false;
long id = reader.ReadInt64();
int strLen = reader.ReadInt32();
StringBuilder str = new StringBuilder(strLen);
for (int i = 0; i < strLen; ++i) {
str.Append(reader.ReadChar());
}
var resourceName = str.ToString();
checkpointResList.Add(resourceName);
}
if (skipBody)
reader.BaseStream.Seek(size, SeekOrigin.Current);
}
}
}
internal JournalSummary OpenForRecovery()
{
if (IsOpen)
{
throw new IOException(String.Format("Journal file '{0}' is already open.", FilePath));
}
if (!FileSystem.FileExists(FilePath))
{
throw new IOException(String.Format("Journal file '{0}' does not exists.", FilePath));
}
// Open the random access file to this journal
File = new StreamFile(FileSystem, FilePath, ReadOnly);
IsOpen = true;
// Create the summary object (by default, not recoverable).
var summary = new JournalSummary(this);
long endPointer = File.Length;
// If end_pointer < 8 then can't recover this journal
if (endPointer < 8)
{
return(summary);
}
// The input stream.
using (var reader = new BinaryReader(File.FileStream, Encoding.Unicode)) {
// Set the journal number for this
JournalNumber = reader.ReadInt64();
long position = 8;
var checkpointResList = new List <string>();
// Start scan
while (true)
{
// If we can't Read 12 bytes ahead, return the summary
if (position + 12 > endPointer)
{
return(summary);
}
long type = reader.ReadInt64();
int size = reader.ReadInt32();
position = position + size + 12;
bool skipBody = true;
// If checkpoint reached then we are recoverable
if (type == 100)
{
summary.LastCheckPoint = position;
summary.CanBeRecovered = true;
// Add the resources input this check point
foreach (var checkpoint in checkpointResList)
{
summary.Resources.Add(checkpoint);
}
// And clear the temporary list.
checkpointResList.Clear();
}
// If end reached, or type is not understood then return
else if (position >= endPointer ||
type < 1 || type > 7)
{
return(summary);
}
// If we are resource type, then load the resource
if (type == 2)
{
// We don't skip body for this type, we Read the content
skipBody = false;
long id = reader.ReadInt64();
int strLen = reader.ReadInt32();
StringBuilder str = new StringBuilder(strLen);
for (int i = 0; i < strLen; ++i)
{
str.Append(reader.ReadChar());
}
var resourceName = str.ToString();
checkpointResList.Add(resourceName);
}
if (skipBody)
{
reader.BaseStream.Seek(size, SeekOrigin.Current);
}
}
}
}
