* Some refactoring.

src/db.cc

@@ -0,0 +1,116 @@
+#include "db.hh"
+#include "util.hh"
+
+#include <db_cxx.h>
+
+
+/* Wrapper classes that ensures that the database is closed upon
+   object destruction. */
+class Db2 : public Db 
+{
+public:
+    Db2(DbEnv *env, u_int32_t flags) : Db(env, flags) { }
+    ~Db2() { close(0); }
+};
+
+
+class DbcClose 
+{
+    Dbc * cursor;
+public:
+    DbcClose(Dbc * c) : cursor(c) { }
+    ~DbcClose() { cursor->close(); }
+};
+
+
+static auto_ptr<Db2> openDB(const string & filename, const string & dbname,
+    bool readonly)
+{
+    auto_ptr<Db2> db(new Db2(0, 0));
+
+    db->open(filename.c_str(), dbname.c_str(),
+        DB_HASH, readonly ? DB_RDONLY : DB_CREATE, 0666);
+
+    return db;
+}
+
+
+static void rethrow(DbException & e)
+{
+    throw Error(e.what());
+}
+
+
+void createDB(const string & filename, const string & dbname)
+{
+    try {
+        openDB(filename, dbname, false);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+bool queryDB(const string & filename, const string & dbname,
+    const string & key, string & data)
+{
+    try {
+
+        int err;
+        auto_ptr<Db2> db = openDB(filename, dbname, true);
+
+        Dbt kt((void *) key.c_str(), key.length());
+        Dbt dt;
+
+        err = db->get(0, &kt, &dt, 0);
+        if (err) return false;
+
+        data = string((char *) dt.get_data(), dt.get_size());
+    
+    } catch (DbException e) { rethrow(e); }
+
+    return true;
+}
+
+
+void setDB(const string & filename, const string & dbname,
+    const string & key, const string & data)
+{
+    try {
+        auto_ptr<Db2> db = openDB(filename, dbname, false);
+        Dbt kt((void *) key.c_str(), key.length());
+        Dbt dt((void *) data.c_str(), data.length());
+        db->put(0, &kt, &dt, 0);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void delDB(const string & filename, const string & dbname,
+    const string & key)
+{
+    try {
+        auto_ptr<Db2> db = openDB(filename, dbname, false);
+        Dbt kt((void *) key.c_str(), key.length());
+        db->del(0, &kt, 0);
+    } catch (DbException e) { rethrow(e); }
+}
+
+
+void enumDB(const string & filename, const string & dbname,
+    DBPairs & contents)
+{
+    try {
+
+        auto_ptr<Db2> db = openDB(filename, dbname, false);
+
+        Dbc * cursor;
+        db->cursor(0, &cursor, 0);
+        DbcClose cursorCloser(cursor);
+
+        Dbt kt, dt;
+        while (cursor->get(&kt, &dt, DB_NEXT) != DB_NOTFOUND) {
+            string key((char *) kt.get_data(), kt.get_size());
+            string data((char *) dt.get_data(), dt.get_size());
+            contents.push_back(DBPair(key, data));
+        }
+
+    } catch (DbException e) { rethrow(e); }
+}