SQLite:: Add some convenience

src/libstore/local-store.cc

@@ -181,24 +181,20 @@ LocalStore::LocalStore(const Params & params)
 
         if (curSchema < 8) {
             SQLiteTxn txn(state->db);
-            if (sqlite3_exec(state->db, "alter table ValidPaths add column ultimate integer", 0, 0, 0) != SQLITE_OK)
+            state->db.exec("alter table ValidPaths add column ultimate integer");
-                throwSQLiteError(state->db, "upgrading database schema");
+            state->db.exec("alter table ValidPaths add column sigs text");
-            if (sqlite3_exec(state->db, "alter table ValidPaths add column sigs text", 0, 0, 0) != SQLITE_OK)
-                throwSQLiteError(state->db, "upgrading database schema");
             txn.commit();
         }
 
         if (curSchema < 9) {
             SQLiteTxn txn(state->db);
-            if (sqlite3_exec(state->db, "drop table FailedPaths", 0, 0, 0) != SQLITE_OK)
+            state->db.exec("drop table FailedPaths");
-                throwSQLiteError(state->db, "upgrading database schema");
             txn.commit();
         }
 
         if (curSchema < 10) {
             SQLiteTxn txn(state->db);
-            if (sqlite3_exec(state->db, "alter table ValidPaths add column ca text", 0, 0, 0) != SQLITE_OK)
+            state->db.exec("alter table ValidPaths add column ca text");
-                throwSQLiteError(state->db, "upgrading database schema");
             txn.commit();
         }
 
@@ -286,8 +282,7 @@ void LocalStore::openDB(State & state, bool create)
     if (sqlite3_busy_timeout(db, 60 * 60 * 1000) != SQLITE_OK)
         throwSQLiteError(db, "setting timeout");
 
-    if (sqlite3_exec(db, "pragma foreign_keys = 1;", 0, 0, 0) != SQLITE_OK)
+    db.exec("pragma foreign_keys = 1");
-        throwSQLiteError(db, "enabling foreign keys");
 
     /* !!! check whether sqlite has been built with foreign key
        support */
@@ -297,8 +292,7 @@ void LocalStore::openDB(State & state, bool create)
        all.  This can cause database corruption if the system
        crashes. */
     string syncMode = settings.fsyncMetadata ? "normal" : "off";
-    if (sqlite3_exec(db, ("pragma synchronous = " + syncMode + ";").c_str(), 0, 0, 0) != SQLITE_OK)
+    db.exec("pragma synchronous = " + syncMode);
-        throwSQLiteError(db, "setting synchronous mode");
 
     /* Set the SQLite journal mode.  WAL mode is fastest, so it's the
        default. */
@@ -326,8 +320,7 @@ void LocalStore::openDB(State & state, bool create)
         const char * schema =
 #include "schema.sql.hh"
             ;
-        if (sqlite3_exec(db, (const char *) schema, 0, 0, 0) != SQLITE_OK)
+        db.exec(schema);
-            throwSQLiteError(db, "initialising database schema");
     }
 }
 
@@ -1297,9 +1290,7 @@ void LocalStore::upgradeStore7()
 void LocalStore::vacuumDB()
 {
     auto state(_state.lock());
-
+    state->db.exec("vacuum");
-    if (sqlite3_exec(state->db, "vacuum;", 0, 0, 0) != SQLITE_OK)
-        throwSQLiteError(state->db, "vacuuming SQLite database");
 }
 
 

src/libstore/nar-info-disk-cache.cc

@@ -78,21 +78,16 @@ public:
         Path dbPath = getCacheDir() + "/nix/binary-cache-v5.sqlite";
         createDirs(dirOf(dbPath));
 
-        if (sqlite3_open_v2(dbPath.c_str(), &state->db.db,
+        state->db = SQLite(dbPath);
-                SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0) != SQLITE_OK)
-            throw Error(format("cannot open store cache ‘%s’") % dbPath);
 
         if (sqlite3_busy_timeout(state->db, 60 * 60 * 1000) != SQLITE_OK)
             throwSQLiteError(state->db, "setting timeout");
 
         // We can always reproduce the cache.
-        if (sqlite3_exec(state->db, "pragma synchronous = off", 0, 0, 0) != SQLITE_OK)
+        state->db.exec("pragma synchronous = off");
-            throwSQLiteError(state->db, "making database asynchronous");
+        state->db.exec("pragma main.journal_mode = truncate");
-        if (sqlite3_exec(state->db, "pragma main.journal_mode = truncate", 0, 0, 0) != SQLITE_OK)
-            throwSQLiteError(state->db, "setting journal mode");
 
-        if (sqlite3_exec(state->db, schema, 0, 0, 0) != SQLITE_OK)
+        state->db.exec(schema);
-            throwSQLiteError(state->db, "initialising database schema");
 
         state->insertCache.create(state->db,
             "insert or replace into BinaryCaches(url, timestamp, storeDir, wantMassQuery, priority) values (?, ?, ?, ?, ?)");

src/libstore/sqlite.cc

@@ -35,6 +35,13 @@ namespace nix {
         throw SQLiteError(format("%1%: %2%") % f.str() % sqlite3_errmsg(db));
 }
 
+SQLite::SQLite(const Path & path)
+{
+    if (sqlite3_open_v2(path.c_str(), &db,
+            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0) != SQLITE_OK)
+        throw Error(format("cannot open SQLite database ‘%s’") % path);
+}
+
 SQLite::~SQLite()
 {
     try {
@@ -45,6 +52,12 @@ SQLite::~SQLite()
     }
 }
 
+void SQLite::exec(const std::string & stmt)
+{
+    if (sqlite3_exec(db, stmt.c_str(), 0, 0, 0) != SQLITE_OK)
+        throwSQLiteError(db, format("executing SQLite statement ‘%s’") % stmt);
+}
+
 void SQLiteStmt::create(sqlite3 * db, const string & s)
 {
     checkInterrupt();

src/libstore/sqlite.hh

@@ -13,10 +13,16 @@ namespace nix {
 /* RAII wrapper to close a SQLite database automatically. */
 struct SQLite
 {
-    sqlite3 * db;
+    sqlite3 * db = 0;
-    SQLite() { db = 0; }
+    SQLite() { }
+    SQLite(const Path & path);
+    SQLite(const SQLite & from) = delete;
+    SQLite& operator = (const SQLite & from) = delete;
+    SQLite& operator = (SQLite && from) { db = from.db; from.db = 0; return *this; }
     ~SQLite();
     operator sqlite3 * () { return db; }
+
+    void exec(const std::string & stmt);
 };
 
 /* RAII wrapper to create and destroy SQLite prepared statements. */