Small tweaks and bugfixes for Issue 18 and 19.

Slight tweak to the no-overlap optimization: only push to
level 2 to reduce the amount of wasted space when the same
small key range is being repeatedly overwritten.

Fix for Issue 18: Avoid failure on Windows by avoiding
deletion of lock file until the end of DestroyDB().

Fix for Issue 19: Disregard sequence numbers when checking for 
overlap in sstable ranges. This fixes issue 19: when writing 
the same key over and over again, we would generate a sequence 
of sstables that were never merged together since their sequence
numbers were disjoint.

Don't ignore map/unmap error checks.

Miscellaneous fixes for small problems Sanjay found while diagnosing
issue/9 and issue/16 (corruption_testr failures).
- log::Reader reports the record type when it finds an unexpected type.
- log::Reader no longer reports an error when it encounters an expected
  zero record regardless of the setting of the "checksum" flag.
- Added a missing forward declaration.
- Documented a side-effects of larger write buffer sizes
  (longer recovery time).



git-svn-id: https://leveldb.googlecode.com/svn/trunk@37 62dab493-f737-651d-591e-8d6aee1b9529

1 files changed, 6 insertions, 6 deletions

diff --git a/db/version_set.h b/db/version_set.h
index f00c35a..693fc6f 100644
--- a/db/version_set.h
+++ b/db/version_set.h
@@ -42,13 +42,13 @@ extern int FindFile(const InternalKeyComparator& icmp,
                     const std::vector<FileMetaData*>& files,
                     const Slice& key);
 
-// Returns true iff some file in "files" overlaps some part of
+// Returns true iff some file in "files" overlaps the user key range
 // [smallest,largest].
 extern bool SomeFileOverlapsRange(
     const InternalKeyComparator& icmp,
     const std::vector<FileMetaData*>& files,
-    const InternalKey& smallest,
-    const InternalKey& largest);
+    const Slice& smallest_user_key,
+    const Slice& largest_user_key);
 
 class Version {
  public:
@@ -78,10 +78,10 @@ class Version {
   void Unref();
 
   // Returns true iff some file in the specified level overlaps
-  // some part of [smallest,largest].
+  // some part of [smallest_user_key,largest_user_key].
   bool OverlapInLevel(int level,
-                      const InternalKey& smallest,
-                      const InternalKey& largest);
+                      const Slice& smallest_user_key,
+                      const Slice& largest_user_key);
 
   int NumFiles(int level) const { return files_[level].size(); }