1 files changed, 152 insertions, 0 deletions
diff --git a/src/dbwrapper.cpp b/src/dbwrapper.cpp
new file mode 100644
index 0000000000..b6307cf0bf
--- /dev/null
+++ b/src/dbwrapper.cpp
@@ -0,0 +1,152 @@
+// Copyright (c) 2012-2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "dbwrapper.h"
+
+#include "util.h"
+#include "random.h"
+
+#include <boost/filesystem.hpp>
+
+#include <leveldb/cache.h>
+#include <leveldb/env.h>
+#include <leveldb/filter_policy.h>
+#include <memenv.h>
+#include <stdint.h>
+
+void HandleError(const leveldb::Status& status) throw(dbwrapper_error)
+{
+    if (status.ok())
+        return;
+    LogPrintf("%s\n", status.ToString());
+    if (status.IsCorruption())
+        throw dbwrapper_error("Database corrupted");
+    if (status.IsIOError())
+        throw dbwrapper_error("Database I/O error");
+    if (status.IsNotFound())
+        throw dbwrapper_error("Database entry missing");
+    throw dbwrapper_error("Unknown database error");
+}
+
+static leveldb::Options GetOptions(size_t nCacheSize)
+{
+    leveldb::Options options;
+    options.block_cache = leveldb::NewLRUCache(nCacheSize / 2);
+    options.write_buffer_size = nCacheSize / 4; // up to two write buffers may be held in memory simultaneously
+    options.filter_policy = leveldb::NewBloomFilterPolicy(10);
+    options.compression = leveldb::kNoCompression;
+    options.max_open_files = 64;
+    if (leveldb::kMajorVersion > 1 || (leveldb::kMajorVersion == 1 && leveldb::kMinorVersion >= 16)) {
+        // LevelDB versions before 1.16 consider short writes to be corruption. Only trigger error
+        // on corruption in later versions.
+        options.paranoid_checks = true;
+    }
+    return options;
+}
+
+CDBWrapper::CDBWrapper(const boost::filesystem::path& path, size_t nCacheSize, bool fMemory, bool fWipe, bool obfuscate)
+{
+    penv = NULL;
+    readoptions.verify_checksums = true;
+    iteroptions.verify_checksums = true;
+    iteroptions.fill_cache = false;
+    syncoptions.sync = true;
+    options = GetOptions(nCacheSize);
+    options.create_if_missing = true;
+    if (fMemory) {
+        penv = leveldb::NewMemEnv(leveldb::Env::Default());
+        options.env = penv;
+    } else {
+        if (fWipe) {
+            LogPrintf("Wiping LevelDB in %s\n", path.string());
+            leveldb::Status result = leveldb::DestroyDB(path.string(), options);
+            HandleError(result);
+        }
+        TryCreateDirectory(path);
+        LogPrintf("Opening LevelDB in %s\n", path.string());
+    }
+    leveldb::Status status = leveldb::DB::Open(options, path.string(), &pdb);
+    HandleError(status);
+    LogPrintf("Opened LevelDB successfully\n");
+
+    // The base-case obfuscation key, which is a noop.
+    obfuscate_key = std::vector<unsigned char>(OBFUSCATE_KEY_NUM_BYTES, '\000');
+
+    bool key_exists = Read(OBFUSCATE_KEY_KEY, obfuscate_key);
+
+    if (!key_exists && obfuscate && IsEmpty()) {
+        // Initialize non-degenerate obfuscation if it won't upset
+        // existing, non-obfuscated data.
+        std::vector<unsigned char> new_key = CreateObfuscateKey();
+
+        // Write `new_key` so we don't obfuscate the key with itself
+        Write(OBFUSCATE_KEY_KEY, new_key);
+        obfuscate_key = new_key;
+
+        LogPrintf("Wrote new obfuscate key for %s: %s\n", path.string(), GetObfuscateKeyHex());
+    }
+
+    LogPrintf("Using obfuscation key for %s: %s\n", path.string(), GetObfuscateKeyHex());
+}
+
+CDBWrapper::~CDBWrapper()
+{
+    delete pdb;
+    pdb = NULL;
+    delete options.filter_policy;
+    options.filter_policy = NULL;
+    delete options.block_cache;
+    options.block_cache = NULL;
+    delete penv;
+    options.env = NULL;
+}
+
+bool CDBWrapper::WriteBatch(CDBBatch& batch, bool fSync) throw(dbwrapper_error)
+{
+    leveldb::Status status = pdb->Write(fSync ? syncoptions : writeoptions, &batch.batch);
+    HandleError(status);
+    return true;
+}
+
+// Prefixed with null character to avoid collisions with other keys
+//
+// We must use a string constructor which specifies length so that we copy
+// past the null-terminator.
+const std::string CDBWrapper::OBFUSCATE_KEY_KEY("\000obfuscate_key", 14);
+
+const unsigned int CDBWrapper::OBFUSCATE_KEY_NUM_BYTES = 8;
+
+/**
+ * Returns a string (consisting of 8 random bytes) suitable for use as an
+ * obfuscating XOR key.
+ */
+std::vector<unsigned char> CDBWrapper::CreateObfuscateKey() const
+{
+    unsigned char buff[OBFUSCATE_KEY_NUM_BYTES];
+    GetRandBytes(buff, OBFUSCATE_KEY_NUM_BYTES);
+    return std::vector<unsigned char>(&buff[0], &buff[OBFUSCATE_KEY_NUM_BYTES]);
+
+}
+
+bool CDBWrapper::IsEmpty()
+{
+    boost::scoped_ptr<CDBIterator> it(NewIterator());
+    it->SeekToFirst();
+    return !(it->Valid());
+}
+
+const std::vector<unsigned char>& CDBWrapper::GetObfuscateKey() const
+{
+    return obfuscate_key;
+}
+
+std::string CDBWrapper::GetObfuscateKeyHex() const
+{
+    return HexStr(obfuscate_key);
+}
+
+CDBIterator::~CDBIterator() { delete piter; }
+bool CDBIterator::Valid() { return piter->Valid(); }
+void CDBIterator::SeekToFirst() { piter->SeekToFirst(); }
+void CDBIterator::Next() { piter->Next(); }