CDB::CDB(const std::string& strFilename, const char* pszMode, bool fFlushOnCloseIn)
: pdb(NULL)
, activeTxn(NULL)
{
int ret;
fReadOnly = (!strchr(pszMode, '+') && !strchr(pszMode, 'w'));
fFlushOnClose = fFlushOnCloseIn;
if (strFilename.empty())
return;
bool fCreate = strchr(pszMode, 'c') != NULL;
unsigned int nFlags = DB_THREAD;
if (fCreate)
nFlags |= DB_CREATE;
{
LOCK(bitdb.cs_db);
if (!bitdb.Open(GetDataDir()))
throw runtime_error("CDB: Failed to open database environment.");
strFile = strFilename;
++bitdb.mapFileUseCount[strFile];
pdb = bitdb.mapDb[strFile];
if (pdb == NULL) {
pdb = new Db(bitdb.dbenv, 0);
bool fMockDb = bitdb.IsMock();
if (fMockDb) {
DbMpoolFile* mpf = pdb->get_mpf();
ret = mpf->set_flags(DB_MPOOL_NOFILE, 1);
if (ret != 0)
throw runtime_error(strprintf("CDB: Failed to configure for no temp file backing for database %s", strFile));
}
ret = pdb->open(NULL, // Txn pointer
fMockDb ? NULL : strFile.c_str(), // Filename
fMockDb ? strFile.c_str() : "main", // Logical db name
DB_BTREE, // Database type
nFlags, // Flags
0);
if (ret != 0) {
delete pdb;
pdb = NULL;
--bitdb.mapFileUseCount[strFile];
strFile = "";
throw runtime_error(strprintf("CDB: Error %d, can't open database %s", ret, strFilename));
}
if (fCreate && !Exists(string("version"))) {
bool fTmp = fReadOnly;
fReadOnly = false;
WriteVersion(CLIENT_VERSION);
fReadOnly = fTmp;
}
bitdb.mapDb[strFile] = pdb;
}
}
}
bool BerkeleyQ::connect()
{
if (NULL != db) return true;
try
{
int ret = 0;
uint env_flags = DB_CREATE | /* Create the environment if it does not exist */
DB_INIT_LOCK | /* Initialize the locking subsystem */
DB_INIT_MPOOL | /* Initialize the memory pool (in-memory cache) */
DB_PRIVATE | /* Region files are not backed by the
* filesystem. Instead, they are backed by
* heap memory. */
DB_THREAD;
DbEnv* env = new DbEnv(0);
ret = env->set_cachesize(0, /* 0 gigabytes */
50 * 1024 * 1024, /* 50 megabytes */
1); /* Create 1 cache. All memory will
* be allocated contiguously. */
env->open(NULL, env_flags, 0);
db = new Db(env, 0); // Instantiate the Db object
db->open(NULL, // Transaction pointer
NULL, // Database file name
NULL, // Optional logical database name
DB_BTREE, // Database access method
DB_CREATE | DB_THREAD, // Open flags
0); // File mode (using defaults)
DbMpoolFile* mp = db->get_mpf();
ret = mp->set_flags(DB_MPOOL_NOFILE, 1);
db->get_env()->lock_id(&locker_id);
start();
}
catch(DbException &e)
{
db = NULL;
q_error("failed connecting to berkeley. %s", e.what());
}
catch(std::exception &e)
{
db = NULL;
q_error("failed connecting to berkeley. %s", e.what());
}
catch (...)
{
db = NULL;
q_error("failed connecting to berkeley. unknown error");
}
return (NULL != db);
}
//
// run --
// Get a set of pages.
//
int
MpoolExample::run(int hits, int pagesize, int npages)
{
db_pgno_t pageno;
int cnt, ret;
void *p;
// Open the file in the environment.
DbMpoolFile *mfp;
if ((ret = memp_fcreate(&mfp, 0)) != 0) {
cerr << "MpoolExample: memp_fcreate failed: "
<< strerror(ret) << "\n";
return (EXIT_FAILURE);
}
mfp->open(MPOOL, 0, 0, pagesize);
cout << "retrieve " << hits << " random pages... ";
srand((unsigned int)time(NULL));
for (cnt = 0; cnt < hits; ++cnt) {
pageno = (rand() % npages) + 1;
if ((ret = mfp->get(&pageno, NULL, 0, &p)) != 0) {
cerr << "MpoolExample: unable to retrieve page "
<< (unsigned long)pageno << ": "
<< strerror(ret) << "\n";
return (EXIT_FAILURE);
}
if (*(db_pgno_t *)p != pageno) {
cerr << "MpoolExample: wrong page retrieved ("
<< (unsigned long)pageno << " != "
<< *(int *)p << ")\n";
return (EXIT_FAILURE);
}
if ((ret = mfp->put(p, DB_PRIORITY_UNCHANGED, 0)) != 0) {
cerr << "MpoolExample: unable to return page "
<< (unsigned long)pageno << ": "
<< strerror(ret) << "\n";
return (EXIT_FAILURE);
}
}
cout << "successful.\n";
// Close the pool.
if ((ret = close(0)) != 0) {
cerr << "MpoolExample: " << strerror(ret) << "\n";
return (EXIT_FAILURE);
}
return (EXIT_SUCCESS);
}
BerkeleyBatch::BerkeleyBatch(BerkeleyDatabase& database, const char* pszMode, bool fFlushOnCloseIn) : pdb(nullptr), activeTxn(nullptr)
{
fReadOnly = (!strchr(pszMode, '+') && !strchr(pszMode, 'w'));
fFlushOnClose = fFlushOnCloseIn;
env = database.env;
if (database.IsDummy()) {
return;
}
const std::string &strFilename = database.strFile;
bool fCreate = strchr(pszMode, 'c') != nullptr;
unsigned int nFlags = DB_THREAD;
if (fCreate)
nFlags |= DB_CREATE;
{
LOCK(cs_db);
if (!env->Open(false /* retry */))
throw std::runtime_error("BerkeleyBatch: Failed to open database environment.");
pdb = env->mapDb[strFilename];
if (pdb == nullptr) {
int ret;
std::unique_ptr<Db> pdb_temp = MakeUnique<Db>(env->dbenv.get(), 0);
bool fMockDb = env->IsMock();
if (fMockDb) {
DbMpoolFile* mpf = pdb_temp->get_mpf();
ret = mpf->set_flags(DB_MPOOL_NOFILE, 1);
if (ret != 0) {
throw std::runtime_error(strprintf("BerkeleyBatch: Failed to configure for no temp file backing for database %s", strFilename));
}
}
ret = pdb_temp->open(nullptr, // Txn pointer
fMockDb ? nullptr : strFilename.c_str(), // Filename
fMockDb ? strFilename.c_str() : "main", // Logical db name
DB_BTREE, // Database type
nFlags, // Flags
0);
if (ret != 0) {
throw std::runtime_error(strprintf("BerkeleyBatch: Error %d, can't open database %s", ret, strFilename));
}
// Call CheckUniqueFileid on the containing BDB environment to
// avoid BDB data consistency bugs that happen when different data
// files in the same environment have the same fileid.
//
// Also call CheckUniqueFileid on all the other g_dbenvs to prevent
// bitcoin from opening the same data file through another
// environment when the file is referenced through equivalent but
// not obviously identical symlinked or hard linked or bind mounted
// paths. In the future a more relaxed check for equal inode and
// device ids could be done instead, which would allow opening
// different backup copies of a wallet at the same time. Maybe even
// more ideally, an exclusive lock for accessing the database could
// be implemented, so no equality checks are needed at all. (Newer
// versions of BDB have an set_lk_exclusive method for this
// purpose, but the older version we use does not.)
for (const auto& env : g_dbenvs) {
CheckUniqueFileid(env.second, strFilename, *pdb_temp, this->env->m_fileids[strFilename]);
}
pdb = pdb_temp.release();
env->mapDb[strFilename] = pdb;
if (fCreate && !Exists(std::string("version"))) {
bool fTmp = fReadOnly;
fReadOnly = false;
WriteVersion(CLIENT_VERSION);
fReadOnly = fTmp;
}
}
++env->mapFileUseCount[strFilename];
strFile = strFilename;
}
}
