private IEnumerator <KeyValuePair <Key, Value> > GetEnumerator()
{
if (NextPageIndex < 0)
{
StopEnumerating = true;
yield break;
}
PageRecord page = ActiveManifest.FindPageForIndex(Level, NextPageIndex++);
if (page == null)
{
StopEnumerating = true;
yield break;
}
var sbt = new SortedBlockTable(Cache, BaseFileName, page.Level, page.Version);
try {
foreach (var pair in sbt.EnumerateFromKey(Cache, StartKey))
{
yield return(pair);
}
} finally {
sbt.Close();
}
}
public void NotifyPageReleased(PageRecord pageRec)
{
string path = null;
path = Config.SortedBlockTableFile(BaseFileName, pageRec.Level, pageRec.Version);
Helper.DeleteFile(path);
}
// Atomically add page specifications to the manifest
public ManifestImmutable AddPage(int level, int version, Key firstKey, Key lastKey)
{
if (level >= MaxLevels)
{
throw new IndexOutOfRangeException();
}
var page = new PageRecord(level, version, firstKey, lastKey);
page.AddRef();
var m = Clone();
m._pages[level].Add(page);
m._pages[level].Sort((x, y) => x.FirstKey.CompareTo(y.FirstKey));
return(m);
}
internal void ReadManifestContents(BinaryReader reader)
{
// read num versions or the razor format at the beginning of the block
int num_versions = reader.Read7BitEncodedInt();
if (num_versions == RAZORFORMATSECRET)
{
RazorFormatVersion = reader.Read7BitEncodedInt();
num_versions = reader.Read7BitEncodedInt();
}
else
{
RazorFormatVersion = -1; // all unnumbered formats
}
for (int i = 0; i < num_versions; i++)
{
_versions[i] = reader.Read7BitEncodedInt();
}
int num_pages = reader.Read7BitEncodedInt();
for (int j = 0; j < num_pages; j++)
{
int num_page_entries = reader.Read7BitEncodedInt();
for (int k = 0; k < num_page_entries; k++)
{
int level = reader.Read7BitEncodedInt();
int version = reader.Read7BitEncodedInt();
int num_key_bytes = reader.Read7BitEncodedInt();
Key startkey = Key.FromBytes(reader.ReadBytes(num_key_bytes));
num_key_bytes = reader.Read7BitEncodedInt();
Key endkey = Key.FromBytes(reader.ReadBytes(num_key_bytes));
var page = new PageRecord(level, version, startkey, endkey);
page.AddRef();
_pages[j].Add(page);
}
}
for (int k = 0; k < num_pages; k++)
{
int num_key_bytes = reader.Read7BitEncodedInt();
_mergeKeys[k] = Key.FromBytes(reader.ReadBytes(num_key_bytes));
}
}
public ManifestImmutable NextMergePage(int level, out PageRecord page)
{
if (level >= MaxLevels)
{
throw new IndexOutOfRangeException();
}
var m = Clone();
var currentKey = _mergeKeys[level];
var levelKeys = _pages[level].Select(key => key.FirstKey).ToList();
int pageNum = levelKeys.BinarySearch(currentKey);
if (pageNum < 0)
{
pageNum = ~pageNum - 1;
}
pageNum = Math.Max(0, pageNum);
int nextPage = pageNum >= levelKeys.Count - 1 ? 0 : pageNum + 1;
m._mergeKeys[level] = _pages[level][nextPage].FirstKey;
page = _pages[level][pageNum];
return(m);
}
