db.java

一高效基于主键值的文件型数据库

         throws DbException, FileNotFoundException;

    // returns: 0, DB_KEYEXIST, or throws error
    public native int put(DbTxn txnid, Dbt key, Dbt data, int flags)
         throws DbException;

    public native void remove(String name, String subname, int flags)
         throws DbException;

    // Note: this callback is not implemented
    // Comparison function.
    // public native void set_bt_compare(DbBtreeCompare bt_compare);

    // Maximum keys per page.
    public native void set_bt_maxkey(int maxkey)
        throws DbException;

    // Minimum keys per page.
    public native void set_bt_minkey(int minkey)
        throws DbException;

    // Note: this callback is not implemented
    // Prefix function.
    // public native void set_bt_prefix(DbBtreePrefix bt_prefix);

    // Set cache size
    public native void set_cachesize(int gbytes, int bytes, int ncaches)
        throws DbException;

    // Note: this callback is not implemented
    // Duplication resolution
    // public native void set_dup_compare(DbDupCompare dup_compare);

    // Error message callback.
    public native void set_errcall(DbErrcall errcall);

    // Error stream.
    public void set_error_stream(OutputStream s)
    {
        DbOutputStreamErrcall errcall = new DbOutputStreamErrcall(s);
        set_errcall(errcall);
    }

    // Error message prefix.
    public native void set_errpfx(String errpfx);

    // Feedback
    public void set_feedback(DbFeedback feedback)
    {
        feedback_ = feedback;
        feedback_changed(feedback);
    }

    // (Internal)
    private native void feedback_changed(DbFeedback feedback);

    // Flags.
    public native void set_flags(/*u_int32_t*/ int flags);

    // Fill factor.
    public native void set_h_ffactor(/*unsigned*/ int h_ffactor);

    // Note: this callback is not implemented
    // Hash function.
    // public native void set_h_hash(DbHash h_hash);

    // Number of elements.
    public native void set_h_nelem(/*unsigned*/ int h_nelem);

    // Byte order.
    public native void set_lorder(int lorder);

    // Underlying page size.
    public native void set_pagesize(/*size_t*/ long pagesize);

    // Variable-length delimiting byte.
    public native void set_re_delim(int re_delim);

    // Length for fixed-length records.
    public native void set_re_len(/*u_int32_t*/ int re_len);

    // Fixed-length padding byte.
    public native void set_re_pad(int re_pad);

    // Source file name.
    public native void set_re_source(String re_source);

    // returns a DbBtreeStat or DbHashStat
    public native Object stat(int flags)
         throws DbException;

    public native void sync(int flags)
         throws DbException;

    public native void upgrade(String name, int flags)
         throws DbException;

    protected native void finalize()
         throws Throwable;

    ////////////////////////////////////////////////////////////////
    //
    // private data
    //
    private long private_info_ = 0;
    private DbEnv dbenv_ = null;
    private DbFeedback feedback_ = null;

    private static boolean already_loaded_ = false;

    public static void load_db()
    {
        if (already_loaded_)
            return;

        // An alternate library name can be specified via a property.
        //
        String overrideLibname = System.getProperty("sleepycat.db.libname");
        if (overrideLibname != null) {
            System.loadLibrary(overrideLibname);
        }
        else {
            String os = System.getProperty("os.name");
            if (os != null && os.startsWith("Windows")) {
                // called libdb_java30.dll on Win/*
                System.loadLibrary("libdb_java" +
                                   DbConstants.DB_VERSION_MAJOR +
                                   DbConstants.DB_VERSION_MINOR);
            }
            else {
                // called libdb_java.so on UNIX
                System.loadLibrary("db_java");
            }
        }

        already_loaded_ = true;
    }

    static private void check_constant(int c1, int c2)
    {
        if (c1 != c2) {
            System.err.println("Db: constant mismatch");
            System.exit(1);
        }
    }

    static {
        Db.load_db();

        // Note: constant values are stored in DbConstants, which
        // is automatically generated.  Initializing constants in
        // static code insulates users from the possibility of
        // changing constants.
        //
        DB_CXX_NO_EXCEPTIONS = DbConstants.DB_CXX_NO_EXCEPTIONS;
        DB_XA_CREATE = DbConstants.DB_XA_CREATE;

        DB_CREATE = DbConstants.DB_CREATE;
        DB_NOMMAP = DbConstants.DB_NOMMAP;
        DB_THREAD = DbConstants.DB_THREAD;

        DB_LOCKDOWN = DbConstants.DB_LOCKDOWN;
        DB_PRIVATE = DbConstants.DB_PRIVATE;
        DB_TXN_SYNC = DbConstants.DB_TXN_SYNC;
        DB_TXN_NOWAIT = DbConstants.DB_TXN_NOWAIT;

        DB_EXCL = DbConstants.DB_EXCL;
        DB_RDONLY = DbConstants.DB_RDONLY;
        DB_TRUNCATE = DbConstants.DB_TRUNCATE;
        DB_UPGRADE = DbConstants.DB_UPGRADE;

        // These constants are not assigned, but rather checked.
        // Having initialized constants for these values allows
        // them to be used as case values in switch statements.
        //
        check_constant(DB_INCOMPLETE, DbConstants.DB_INCOMPLETE);
        check_constant(DB_KEYEMPTY, DbConstants.DB_KEYEMPTY);
        check_constant(DB_KEYEXIST, DbConstants.DB_KEYEXIST);
        check_constant(DB_LOCK_DEADLOCK, DbConstants.DB_LOCK_DEADLOCK);
        check_constant(DB_LOCK_NOTGRANTED, DbConstants.DB_LOCK_NOTGRANTED);
        check_constant(DB_NOTFOUND, DbConstants.DB_NOTFOUND);
        check_constant(DB_OLD_VERSION, DbConstants.DB_OLD_VERSION);
        check_constant(DB_RUNRECOVERY, DbConstants.DB_RUNRECOVERY);

        DB_FORCE = DbConstants.DB_FORCE;
        DB_INIT_CDB = DbConstants.DB_INIT_CDB;
        DB_INIT_LOCK = DbConstants.DB_INIT_LOCK;
        DB_INIT_LOG = DbConstants.DB_INIT_LOG;
        DB_INIT_MPOOL = DbConstants.DB_INIT_MPOOL;
        DB_INIT_TXN = DbConstants.DB_INIT_TXN;
        DB_RECOVER = DbConstants.DB_RECOVER;
        DB_RECOVER_FATAL = DbConstants.DB_RECOVER_FATAL;
        DB_SYSTEM_MEM = DbConstants.DB_SYSTEM_MEM;
        DB_TXN_NOSYNC = DbConstants.DB_TXN_NOSYNC;
        DB_USE_ENVIRON = DbConstants.DB_USE_ENVIRON;
        DB_USE_ENVIRON_ROOT = DbConstants.DB_USE_ENVIRON_ROOT;

        DB_VERB_CHKPOINT = DbConstants.DB_VERB_CHKPOINT;
        DB_VERB_DEADLOCK = DbConstants.DB_VERB_DEADLOCK;
        DB_VERB_RECOVERY = DbConstants.DB_VERB_RECOVERY;
        DB_VERB_WAITSFOR = DbConstants.DB_VERB_WAITSFOR;

        DB_LOCK_NORUN = DbConstants.DB_LOCK_NORUN;
        DB_LOCK_DEFAULT = DbConstants.DB_LOCK_DEFAULT;
        DB_LOCK_OLDEST = DbConstants.DB_LOCK_OLDEST;
        DB_LOCK_RANDOM = DbConstants.DB_LOCK_RANDOM;
        DB_LOCK_YOUNGEST = DbConstants.DB_LOCK_YOUNGEST;

        DB_DUP = DbConstants.DB_DUP;
        DB_DUPSORT = DbConstants.DB_DUPSORT;
        DB_RECNUM = DbConstants.DB_RECNUM;
        DB_RENUMBER = DbConstants.DB_RENUMBER;
        DB_REVSPLITOFF = DbConstants.DB_REVSPLITOFF;
        DB_SNAPSHOT = DbConstants.DB_SNAPSHOT;

        DB_LOCK_NOWAIT = DbConstants.DB_LOCK_NOWAIT;
        DB_LOCK_CONFLICT = DbConstants.DB_LOCK_CONFLICT;

        DB_LOCK_RW_N = DbConstants.DB_LOCK_RW_N;

        DB_ARCH_ABS = DbConstants.DB_ARCH_ABS;
        DB_ARCH_DATA = DbConstants.DB_ARCH_DATA;
        DB_ARCH_LOG = DbConstants.DB_ARCH_LOG;

        DB_AFTER = DbConstants.DB_AFTER;
        DB_APPEND = DbConstants.DB_APPEND;
        DB_BEFORE = DbConstants.DB_BEFORE;
        DB_CHECKPOINT = DbConstants.DB_CHECKPOINT;
        DB_CONSUME = DbConstants.DB_CONSUME;
        DB_CURLSN = DbConstants.DB_CURLSN;
        DB_CURRENT = DbConstants.DB_CURRENT;
        DB_FIRST = DbConstants.DB_FIRST;
        DB_FLUSH = DbConstants.DB_FLUSH;
        DB_GET_BOTH = DbConstants.DB_GET_BOTH;
        DB_GET_RECNO = DbConstants.DB_GET_RECNO;
        DB_JOIN_ITEM = DbConstants.DB_JOIN_ITEM;
        DB_KEYFIRST = DbConstants.DB_KEYFIRST;
        DB_KEYLAST = DbConstants.DB_KEYLAST;
        DB_LAST = DbConstants.DB_LAST;
        DB_NEXT = DbConstants.DB_NEXT;
        DB_NEXT_DUP = DbConstants.DB_NEXT_DUP;
        DB_NEXT_NODUP = DbConstants.DB_NEXT_NODUP;
        DB_NOOVERWRITE = DbConstants.DB_NOOVERWRITE;
        DB_NOSYNC = DbConstants.DB_NOSYNC;
        DB_POSITION = DbConstants.DB_POSITION;
        DB_PREV = DbConstants.DB_PREV;
        DB_RECORDCOUNT = DbConstants.DB_RECORDCOUNT;
        DB_SET = DbConstants.DB_SET;
        DB_SET_RANGE = DbConstants.DB_SET_RANGE;
        DB_SET_RECNO = DbConstants.DB_SET_RECNO;
        DB_WRITECURSOR = DbConstants.DB_WRITECURSOR;
        DB_RMW = DbConstants.DB_RMW;

        DB_DBT_MALLOC = DbConstants.DB_DBT_MALLOC;
        DB_DBT_PARTIAL = DbConstants.DB_DBT_PARTIAL;
        DB_DBT_REALLOC = DbConstants.DB_DBT_REALLOC;
        DB_DBT_USERMEM = DbConstants.DB_DBT_USERMEM;
    }
}

// end of Db.java