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| author | Sanjay Ghemawat <sanjay@google.com> | 2014-12-11 08:13:18 -0800 |
|---|---|---|
| committer | Chris Mumford <cmumford@chromium.org> | 2015-08-11 14:56:39 -0700 |
| commit | ac1d69da31205a979b5a8510f33c31ae977530f0 (patch) | |
| tree | a1bbfceb74a93d34bda9544f8ad62f3555884805 /db/version_set.h | |
| parent | 77948e7eec0613fb5cbecb7e320b9498607030b5 (diff) | |
| download | leveldb-ac1d69da31205a979b5a8510f33c31ae977530f0.tar.gz | |
LevelDB now attempts to reuse the preceding MANIFEST and log file when re-opened.
(Based on a suggestion by cmumford.)
"open" benchmark on my workstation speeds up significantly since we
can now avoid three fdatasync calls and a compaction per open:
Before: ~80000 microseconds
After: ~130 microseconds
Details:
(1) Added Options::reuse_logs (currently defaults to false) to control
new behavior. The intention is to change the default to true after some
baking.
(2) Added Env::NewAppendableFile() whose default implementation returns
a not-supported error.
(3) VersionSet::Recovery attempts to reuse the MANIFEST from which
it is recovering.
(4) DBImpl recovery attempts to reuse the last log file and memtable.
(5) db_test.cc now tests a new configuration that sets reuse_logs to true.
(6) fault_injection_test also tests a reuse_logs==true config.
(7) Added a new recovery_test.
Diffstat (limited to 'db/version_set.h')
| -rw-r--r-- | db/version_set.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/db/version_set.h b/db/version_set.h index 8dc14b8..1dec745 100644 --- a/db/version_set.h +++ b/db/version_set.h @@ -179,7 +179,7 @@ class VersionSet { EXCLUSIVE_LOCKS_REQUIRED(mu); // Recover the last saved descriptor from persistent storage. - Status Recover(); + Status Recover(bool *save_manifest); // Return the current version. Version* current() const { return current_; } @@ -274,6 +274,8 @@ class VersionSet { friend class Compaction; friend class Version; + bool ReuseManifest(const std::string& dscname, const std::string& dscbase); + void Finalize(Version* v); void GetRange(const std::vector<FileMetaData*>& inputs, |