From 878061317ebee6fbf2b977a2cb7b918e2aea6e08 Mon Sep 17 00:00:00 2001
From: Miguel Freitas <miguel@cptibr.org>
Date: Wed, 2 Oct 2013 20:03:32 -0300
Subject: [PATCH] leveldb repair for torrents

---
 libtorrent/src/storage.cpp | 36 +++++++++++++++++++++++++-----------
 src/leveldb.cpp            | 20 ++++++++++++++++++++
 src/leveldb.h              |  5 +++++
 3 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/libtorrent/src/storage.cpp b/libtorrent/src/storage.cpp
index 66f2b84a..9d900ef2 100644
--- a/libtorrent/src/storage.cpp
+++ b/libtorrent/src/storage.cpp
@@ -540,10 +540,17 @@ namespace libtorrent
 
         std::string postStr(static_cast<char *>(bufs[0].iov_base), bufs[0].iov_len);
 
-        if( Write(std::make_pair('p', slot), postStr) ) {
-            return postStr.size();
-        } else {
-            return -1;
+        int tries = 2;
+        while( tries-- ) {
+            try {
+                if( Write(std::make_pair('p', slot), postStr) ) {
+                    return postStr.size();
+                } else {
+                    return -1;
+                }
+            } catch( leveldb_error &e ) {
+                RepairDB();
+            }
         }
 
 	}
@@ -572,13 +579,20 @@ namespace libtorrent
         TORRENT_ASSERT(num_bufs == 1);
         TORRENT_ASSERT(offset == 0);
 
-        std::string postStr;
-        if( Read(std::make_pair('p', slot), postStr) ) {
-            TORRENT_ASSERT(bufs[0].iov_len >= postStr.size());
-            memcpy(bufs[0].iov_base, postStr.data(), postStr.size());
-            return postStr.size();
-        } else {
-            return 0;
+        int tries = 2;
+        while( tries-- ) {
+            try {
+                std::string postStr;
+                if( Read(std::make_pair('p', slot), postStr) ) {
+                    TORRENT_ASSERT(bufs[0].iov_len >= postStr.size());
+                    memcpy(bufs[0].iov_base, postStr.data(), postStr.size());
+                    return postStr.size();
+                } else {
+                    return 0;
+                }
+            } catch( leveldb_error &e ) {
+                RepairDB();
+            }
         }
 	}
 
diff --git a/src/leveldb.cpp b/src/leveldb.cpp
index e66f8514..f95367d1 100644
--- a/src/leveldb.cpp
+++ b/src/leveldb.cpp
@@ -35,6 +35,8 @@ static leveldb::Options GetOptions(size_t nCacheSize) {
 }
 
 CLevelDB::CLevelDB(const boost::filesystem::path &path, size_t nCacheSize, bool fMemory, bool fWipe) {
+    m_path = path.string();
+    m_nCacheSize = nCacheSize;
     penv = NULL;
     readoptions.verify_checksums = true;
     iteroptions.verify_checksums = true;
@@ -79,3 +81,21 @@ bool CLevelDB::WriteBatch(CLevelDBBatch &batch, bool fSync) throw(leveldb_error)
     }
     return true;
 }
+
+void CLevelDB::RepairDB()
+{
+    printf("CLevelDB::RepairDB trying to repair...\n");
+    delete pdb;
+    pdb = NULL;
+
+    leveldb::Status status;
+
+    status = leveldb::RepairDB(m_path, options);
+    if (!status.ok())
+        throw std::runtime_error(strprintf("CLevelDB(): error RepairDB %s", status.ToString().c_str()));
+
+    status = leveldb::DB::Open(options, m_path, &pdb);
+    if (!status.ok())
+        throw std::runtime_error(strprintf("CLevelDB(): error opening database environment %s", status.ToString().c_str()));
+    printf("Repaired and reopened LevelDB successfully\n");
+}
diff --git a/src/leveldb.h b/src/leveldb.h
index 79262edb..ebf9e558 100644
--- a/src/leveldb.h
+++ b/src/leveldb.h
@@ -76,6 +76,9 @@ private:
     // the database itself
     leveldb::DB *pdb;
 
+    std::string m_path;
+    size_t m_nCacheSize;
+
 public:
     CLevelDB(const boost::filesystem::path &path, size_t nCacheSize, bool fMemory = false, bool fWipe = false);
     ~CLevelDB();
@@ -148,6 +151,8 @@ public:
     leveldb::Iterator *NewIterator() {
         return pdb->NewIterator(iteroptions);
     }
+
+    void RepairDB();
 };
 
 #endif // BITCOIN_LEVELDB_H