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Make gnc_lock_database a GncDbiSqlConnection member function.
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Called from the constructor, so effective RAII with unlock_database called
from the destructor.
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@jralls
jralls committed Oct 28, 2016
1 parent 00e0a6e commit 314a5e1
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Showing 5 changed files with 152 additions and 172 deletions.
185 changes: 27 additions & 158 deletions src/backend/dbi/gnc-backend-dbi.cpp
View file
Expand Up @@ -101,8 +101,6 @@ static QofLogModule log_module = G_LOG_DOMAIN;
// gnc-dbiproviderimpl.hpp has templates that need log_module defined.
#include "gnc-dbiproviderimpl.hpp"

static gchar lock_table[] = "gnclock";

#define FILE_URI_TYPE "file"
#define FILE_URI_PREFIX (FILE_URI_TYPE "://")
#define SQLITE3_URI_TYPE "sqlite3"
Expand All @@ -114,7 +112,6 @@ constexpr const char* MYSQL_TIMESPEC_STR_FORMAT = "%04d%02d%02d%02d%02d%02d";
constexpr const char* PGSQL_TIMESPEC_STR_FORMAT = "%04d%02d%02d %02d%02d%02d";

static void adjust_sql_options (dbi_conn connection);
static gboolean gnc_dbi_lock_database (QofBackend*, dbi_conn, gboolean);
static bool save_may_clobber_data (dbi_conn conn);
static void init_sql_backend (GncDbiBackend* dbi_be);

Expand Down Expand Up @@ -480,19 +477,18 @@ gnc_dbi_session_begin<DbType::DBI_SQLITE>(QofBackend* qbe, QofSession* session,
g_unlink (filepath.c_str());
}
LEAVE("Bad DBI Library");
return;
}
if (!gnc_dbi_lock_database (qbe, conn, ignore_lock))
{
qof_backend_set_error (qbe, ERR_BACKEND_LOCKED);
LEAVE("Locked");
return;
}

be->connect(nullptr);
be->connect(
new GncDbiSqlConnection (new GncDbiProviderImpl<DbType::DBI_SQLITE>,
qbe, conn, lock_table));
try
{
be->connect(new GncDbiSqlConnection(make_dbi_provider<DbType::DBI_SQLITE>(),
qbe, conn, ignore_lock));
}
catch (std::runtime_error& err)
{
return;
}

/* We should now have a proper session set up.
* Let's start logging */
Expand Down Expand Up @@ -555,136 +551,6 @@ mysql_error_fn (dbi_conn conn, void* user_data)
}
}


/* FIXME: Move to GncDbiSqlConnection. */
static gboolean
gnc_dbi_lock_database (QofBackend* qbe, dbi_conn conn, gboolean ignore_lock)
{

GncDbiBackend* qe = (GncDbiBackend*)qbe;

dbi_result result;
const gchar* dbname = dbi_conn_get_option (conn, "dbname");
/* Create the table if it doesn't exist */
result = dbi_conn_get_table_list (conn, dbname, lock_table);
if (! (result && dbi_result_get_numrows (result)))
{
if (result)
{
dbi_result_free (result);
result = nullptr;
}
result = dbi_conn_queryf (conn,
"CREATE TABLE %s ( Hostname varchar(%d), PID int )", lock_table,
GNC_HOST_NAME_MAX);
if (dbi_conn_error (conn, nullptr))
{
const gchar* errstr;
dbi_conn_error (conn, &errstr);
PERR ("Error %s creating lock table", errstr);
qof_backend_set_error (qbe, ERR_BACKEND_SERVER_ERR);
if (result)
{
dbi_result_free (result);
result = nullptr;
}
return FALSE;
}
if (result)
{
dbi_result_free (result);
result = nullptr;
}
}
if (result)
{
dbi_result_free (result);
result = nullptr;
}

/* Protect everything with a single transaction to prevent races */
if ((result = dbi_conn_query (conn, "BEGIN")))
{
/* Check for an existing entry; delete it if ignore_lock is true, otherwise fail */
gchar hostname[ GNC_HOST_NAME_MAX + 1 ];
if (result)
{
dbi_result_free (result);
result = nullptr;
}
result = dbi_conn_queryf (conn, "SELECT * FROM %s", lock_table);
if (result && dbi_result_get_numrows (result))
{
dbi_result_free (result);
result = nullptr;
if (!ignore_lock)
{
qof_backend_set_error (qbe, ERR_BACKEND_LOCKED);
/* FIXME: After enhancing the qof_backend_error mechanism, report in the dialog what is the hostname of the machine holding the lock. */
dbi_conn_query (conn, "ROLLBACK");
return FALSE;
}
result = dbi_conn_queryf (conn, "DELETE FROM %s", lock_table);
if (!result)
{
qof_backend_set_error (qbe, ERR_BACKEND_SERVER_ERR);
qof_backend_set_message (qbe, "Failed to delete lock record");
result = dbi_conn_query (conn, "ROLLBACK");
if (result)
{
dbi_result_free (result);
result = nullptr;
}
return FALSE;
}
if (result)
{
dbi_result_free (result);
result = nullptr;
}
}
/* Add an entry and commit the transaction */
memset (hostname, 0, sizeof (hostname));
gethostname (hostname, GNC_HOST_NAME_MAX);
result = dbi_conn_queryf (conn,
"INSERT INTO %s VALUES ('%s', '%d')",
lock_table, hostname, (int)GETPID ());
if (!result)
{
qof_backend_set_error (qbe, ERR_BACKEND_SERVER_ERR);
qof_backend_set_message (qbe, "Failed to create lock record");
result = dbi_conn_query (conn, "ROLLBACK");
if (result)
{
dbi_result_free (result);
result = nullptr;
}
return FALSE;
}
if (result)
{
dbi_result_free (result);
result = nullptr;
}
result = dbi_conn_query (conn, "COMMIT");
if (result)
{
dbi_result_free (result);
result = nullptr;
}
return TRUE;
}
/* Couldn't get a transaction (probably couldn't get a lock), so fail */
qof_backend_set_error (qbe, ERR_BACKEND_SERVER_ERR);
qof_backend_set_message (qbe, "SQL Backend failed to obtain a transaction");
if (result)
{
dbi_result_free (result);
result = nullptr;
}
return FALSE;
}

#define SQL_OPTION_TO_REMOVE "NO_ZERO_DATE"

/* Given an sql_options string returns a copy of the string adjusted as
Expand Down Expand Up @@ -796,8 +662,6 @@ gnc_dbi_session_begin<DbType::DBI_MYSQL> (QofBackend* qbe, QofSession* session,
return;
}

if (!gnc_dbi_lock_database (qbe, conn, ignore_lock))
return;
}
else
{
Expand Down Expand Up @@ -832,8 +696,6 @@ gnc_dbi_session_begin<DbType::DBI_MYSQL> (QofBackend* qbe, QofSession* session,
dbi_conn_queryf (conn, "DROP DATABASE %s", uri.dbname());
return;
}
if (!gnc_dbi_lock_database (qbe, conn, ignore_lock))
return;
}
else
{
Expand All @@ -843,10 +705,15 @@ gnc_dbi_session_begin<DbType::DBI_MYSQL> (QofBackend* qbe, QofSession* session,
}

be->connect(nullptr);
be->connect(
new GncDbiSqlConnection (new GncDbiProviderImpl<DbType::DBI_MYSQL>,
qbe, conn, lock_table));

try
{
be->connect(new GncDbiSqlConnection(make_dbi_provider<DbType::DBI_MYSQL>(),
qbe, conn, ignore_lock));
}
catch (std::runtime_error& err)
{
return;
}
/* We should now have a proper session set up.
* Let's start logging */
auto translog_path = gnc_build_translog_path (uri.basename().c_str());
Expand Down Expand Up @@ -956,8 +823,6 @@ gnc_dbi_session_begin<DbType::DBI_PGSQL> (QofBackend* qbe, QofSession* session,
return;
}

if (!gnc_dbi_lock_database (qbe, conn, ignore_lock))
return;
}
else
{
Expand Down Expand Up @@ -993,8 +858,6 @@ gnc_dbi_session_begin<DbType::DBI_PGSQL> (QofBackend* qbe, QofSession* session,
LEAVE("Error");
return;
}
if (!gnc_dbi_lock_database (qbe, conn, ignore_lock))
return;
}
else
{
Expand All @@ -1003,9 +866,15 @@ gnc_dbi_session_begin<DbType::DBI_PGSQL> (QofBackend* qbe, QofSession* session,
}
}
be->connect(nullptr);
be->connect(
new GncDbiSqlConnection (new GncDbiProviderImpl<DbType::DBI_PGSQL>,
qbe, conn, lock_table));
try
{
be->connect(new GncDbiSqlConnection(make_dbi_provider<DbType::DBI_PGSQL>(),
qbe, conn, ignore_lock));
}
catch (std::runtime_error& err)
{
return;
}

/* We should now have a proper session set up.
* Let's start logging */
Expand Down
2 changes: 2 additions & 0 deletions src/backend/dbi/gnc-dbiprovider.hpp
View file
Expand Up @@ -49,4 +49,6 @@ class GncDbiProvider
virtual void drop_index(dbi_conn conn, const std::string& index) = 0;
};

using GncDbiProviderPtr = std::unique_ptr<GncDbiProvider>;

#endif //__GNC_DBIPROVIDER_HPP__
7 changes: 6 additions & 1 deletion src/backend/dbi/gnc-dbiproviderimpl.hpp
View file
Expand Up @@ -30,7 +30,6 @@ extern "C"
#include "gnc-backend-dbi.hpp"
#include "gnc-dbiprovider.hpp"


template <DbType T>
class GncDbiProviderImpl : public GncDbiProvider
{
Expand All @@ -41,6 +40,12 @@ class GncDbiProviderImpl : public GncDbiProvider
void drop_index(dbi_conn conn, const std::string& index);
};

template <DbType T> GncDbiProviderPtr
make_dbi_provider()
{
return GncDbiProviderPtr(new GncDbiProviderImpl<T>);
}

template<> void
GncDbiProviderImpl<DbType::DBI_SQLITE>::append_col_def(std::string& ddl,
const GncSqlColumnInfo& info)
Expand Down

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