cpython/Modules/bsddbmodule.c

/* Berkeley DB interface.
   Author: Michael McLay
   Hacked: Guido van Rossum
   Btree and Recno additions plus sequence methods: David Ely
   Hacked by Gustavo Niemeyer <niemeyer@conectiva.com> fixing recno
   support.

   XXX To do:
   - provide a way to access the various hash functions
   - support more open flags

   The windows port of the Berkeley DB code is hard to find on the web:
   www.nightmare.com/software.html
*/

#include "Python.h"
#ifdef WITH_THREAD
#include "pythread.h"
#endif

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef HAVE_DB_185_H
#include <db_185.h>
#else
#include <db.h>
#endif
/* Please don't include internal header files of the Berkeley db package
   (it messes up the info required in the Setup file) */

typedef struct {
    PyObject_HEAD
    DB *di_bsddb;
    int di_size;        /* -1 means recompute */
    int di_type;
#ifdef WITH_THREAD
    PyThread_type_lock di_lock;
#endif
} bsddbobject;

static PyTypeObject Bsddbtype;

#define is_bsddbobject(v) ((v)->ob_type == &Bsddbtype)
#define check_bsddbobject_open(v, r) if ((v)->di_bsddb == NULL) \
               { PyErr_SetString(BsddbError, \
                                 "BSDDB object has already been closed"); \
                 return r; }

static PyObject *BsddbError;

static PyObject *
newdbhashobject(char *file, int flags, int mode,
                int bsize, int ffactor, int nelem, int cachesize,
                int hash, int lorder)
{
    bsddbobject *dp;
    HASHINFO info;

    if ((dp = PyObject_New(bsddbobject, &Bsddbtype)) == NULL)
        return NULL;

    info.bsize = bsize;
    info.ffactor = ffactor;
    info.nelem = nelem;
    info.cachesize = cachesize;
    info.hash = NULL; /* XXX should derive from hash argument */
    info.lorder = lorder;

#ifdef O_BINARY
    flags |= O_BINARY;
#endif
    Py_BEGIN_ALLOW_THREADS
    dp->di_bsddb = dbopen(file, flags, mode, DB_HASH, &info);
    Py_END_ALLOW_THREADS
    if (dp->di_bsddb == NULL) {
        PyErr_SetFromErrno(BsddbError);
#ifdef WITH_THREAD
        dp->di_lock = NULL;
#endif
        Py_DECREF(dp);
        return NULL;
    }

    dp->di_size = -1;
    dp->di_type = DB_HASH;

#ifdef WITH_THREAD
    dp->di_lock = PyThread_allocate_lock();
    if (dp->di_lock == NULL) {
        PyErr_SetString(BsddbError, "can't allocate lock");
        Py_DECREF(dp);
        return NULL;
    }
#endif

    return (PyObject *)dp;
}

static PyObject *
newdbbtobject(char *file, int flags, int mode,
              int btflags, int cachesize, int maxkeypage,
              int minkeypage, int psize, int lorder)
{
    bsddbobject *dp;
    BTREEINFO info;

    if ((dp = PyObject_New(bsddbobject, &Bsddbtype)) == NULL)
        return NULL;

    info.flags = btflags;
    info.cachesize = cachesize;
    info.maxkeypage = maxkeypage;
    info.minkeypage = minkeypage;
    info.psize = psize;
    info.lorder = lorder;
    info.compare = 0; /* Use default comparison functions, for now..*/
    info.prefix = 0;

#ifdef O_BINARY
    flags |= O_BINARY;
#endif
    Py_BEGIN_ALLOW_THREADS
    dp->di_bsddb = dbopen(file, flags, mode, DB_BTREE, &info);
    Py_END_ALLOW_THREADS
    if (dp->di_bsddb == NULL) {
        PyErr_SetFromErrno(BsddbError);
#ifdef WITH_THREAD
        dp->di_lock = NULL;
#endif
        Py_DECREF(dp);
        return NULL;
    }

    dp->di_size = -1;
    dp->di_type = DB_BTREE;

#ifdef WITH_THREAD
    dp->di_lock = PyThread_allocate_lock();
    if (dp->di_lock == NULL) {
        PyErr_SetString(BsddbError, "can't allocate lock");
        Py_DECREF(dp);
        return NULL;
    }
#endif

    return (PyObject *)dp;
}

static PyObject *
newdbrnobject(char *file, int flags, int mode,
              int rnflags, int cachesize, int psize, int lorder,
              size_t reclen, u_char bval, char *bfname)
{
    bsddbobject *dp;
    RECNOINFO info;
    int fd;

    if ((dp = PyObject_New(bsddbobject, &Bsddbtype)) == NULL)
        return NULL;

    info.flags = rnflags;
    info.cachesize = cachesize;
    info.psize = psize;
    info.lorder = lorder;
    info.reclen = reclen;
    info.bval = bval;
    info.bfname = bfname;

#ifdef O_BINARY
    flags |= O_BINARY;
#endif
    /* This is a hack to avoid a dbopen() bug that happens when
     * it fails. */
    fd = open(file, flags);
    if (fd == -1) {
        dp->di_bsddb = NULL;
    }
    else {
        close(fd);
        Py_BEGIN_ALLOW_THREADS
        dp->di_bsddb = dbopen(file, flags, mode, DB_RECNO, &info);
        Py_END_ALLOW_THREADS
    }
    if (dp->di_bsddb == NULL) {
        PyErr_SetFromErrno(BsddbError);
#ifdef WITH_THREAD
        dp->di_lock = NULL;
#endif
        Py_DECREF(dp);
        return NULL;
    }

    dp->di_size = -1;
    dp->di_type = DB_RECNO;

#ifdef WITH_THREAD
    dp->di_lock = PyThread_allocate_lock();
    if (dp->di_lock == NULL) {
        PyErr_SetString(BsddbError, "can't allocate lock");
        Py_DECREF(dp);
        return NULL;
    }
#endif

    return (PyObject *)dp;
}

static void
bsddb_dealloc(bsddbobject *dp)
{
#ifdef WITH_THREAD
    if (dp->di_lock) {
        PyThread_acquire_lock(dp->di_lock, 0);
        PyThread_release_lock(dp->di_lock);
        PyThread_free_lock(dp->di_lock);
        dp->di_lock = NULL;
    }
#endif
    if (dp->di_bsddb != NULL) {
        int status;
        Py_BEGIN_ALLOW_THREADS
        status = (dp->di_bsddb->close)(dp->di_bsddb);
        Py_END_ALLOW_THREADS
        if (status != 0)
            fprintf(stderr,
                "Python bsddb: close errno %d in dealloc\n",
                errno);
    }
    PyObject_Del(dp);
}

#ifdef WITH_THREAD
#define BSDDB_BGN_SAVE(_dp) \
    Py_BEGIN_ALLOW_THREADS PyThread_acquire_lock(_dp->di_lock,1);
#define BSDDB_END_SAVE(_dp) \
    PyThread_release_lock(_dp->di_lock); Py_END_ALLOW_THREADS
#else
#define BSDDB_BGN_SAVE(_dp) Py_BEGIN_ALLOW_THREADS
#define BSDDB_END_SAVE(_dp) Py_END_ALLOW_THREADS
#endif

static Py_ssize_t
bsddb_length(bsddbobject *dp)
{
    check_bsddbobject_open(dp, -1);
    if (dp->di_size < 0) {
        DBT krec, drec;
        int status;
        int size = 0;
        BSDDB_BGN_SAVE(dp)
        for (status = (dp->di_bsddb->seq)(dp->di_bsddb,
                                          &krec, &drec,R_FIRST);
             status == 0;
             status = (dp->di_bsddb->seq)(dp->di_bsddb,
                                          &krec, &drec, R_NEXT))
            size++;
        BSDDB_END_SAVE(dp)
        if (status < 0) {
            PyErr_SetFromErrno(BsddbError);
            return -1;
        }
        dp->di_size = size;
    }
    return dp->di_size;
}

static PyObject *
bsddb_subscript(bsddbobject *dp, PyObject *key)
{
    int status;
    DBT krec, drec;
    char *data = NULL;
    char buf[4096];
    int size;
    PyObject *result;
    recno_t recno;

    if (dp->di_type == DB_RECNO) {
        if (!PyArg_Parse(key, "i", &recno)) {
            PyErr_SetString(PyExc_TypeError,
                            "key type must be integer");
            return NULL;
        }
        krec.data = &recno;
        krec.size = sizeof(recno);
    }
    else {
        if (!PyArg_Parse(key, "s#", &data, &size)) {
            PyErr_SetString(PyExc_TypeError,
                            "key type must be string");
            return NULL;
        }
        krec.data = data;
        krec.size = size;
    }
    check_bsddbobject_open(dp, NULL);

    BSDDB_BGN_SAVE(dp)
    status = (dp->di_bsddb->get)(dp->di_bsddb, &krec, &drec, 0);
    if (status == 0) {
        if (drec.size > sizeof(buf)) data = malloc(drec.size);
        else data = buf;
        if (data!=NULL) memcpy(data,drec.data,drec.size);
    }
    BSDDB_END_SAVE(dp)
    if (data==NULL) return PyErr_NoMemory();
    if (status != 0) {
        if (status < 0)
            PyErr_SetFromErrno(BsddbError);
        else
            PyErr_SetObject(PyExc_KeyError, key);
        return NULL;
    }

    result = PyString_FromStringAndSize(data, (int)drec.size);
    if (data != buf) free(data);
    return result;
}

static int
bsddb_ass_sub(bsddbobject *dp, PyObject *key, PyObject *value)
{
    int status;
    DBT krec, drec;
    char *data;
    int size;
    recno_t recno;

    if (dp->di_type == DB_RECNO) {
        if (!PyArg_Parse(key, "i", &recno)) {
            PyErr_SetString(PyExc_TypeError,
                            "bsddb key type must be integer");
            return -1;
        }
        krec.data = &recno;
        krec.size = sizeof(recno);
    }
    else {
        if (!PyArg_Parse(key, "s#", &data, &size)) {
            PyErr_SetString(PyExc_TypeError,
                            "bsddb key type must be string");
            return -1;
        }
        krec.data = data;
        krec.size = size;
    }
    check_bsddbobject_open(dp, -1);
    dp->di_size = -1;
    if (value == NULL) {
        BSDDB_BGN_SAVE(dp)
        status = (dp->di_bsddb->del)(dp->di_bsddb, &krec, 0);
        BSDDB_END_SAVE(dp)
    }
    else {
        if (!PyArg_Parse(value, "s#", &data, &size)) {
            PyErr_SetString(PyExc_TypeError,
                            "bsddb value type must be string");
            return -1;
        }
        drec.data = data;
        drec.size = size;
        BSDDB_BGN_SAVE(dp)
        status = (dp->di_bsddb->put)(dp->di_bsddb, &krec, &drec, 0);
        BSDDB_END_SAVE(dp)
    }
    if (status != 0) {
        if (status < 0)
            PyErr_SetFromErrno(BsddbError);
        else
            PyErr_SetObject(PyExc_KeyError, key);
        return -1;
    }
    return 0;
}

static PyMappingMethods bsddb_as_mapping = {
    (lenfunc)bsddb_length,              /*mp_length*/
    (binaryfunc)bsddb_subscript,        /*mp_subscript*/
    (objobjargproc)bsddb_ass_sub,       /*mp_ass_subscript*/
};

static PyObject *
bsddb_close(bsddbobject *dp)
{
    if (dp->di_bsddb != NULL) {
        int status;
        BSDDB_BGN_SAVE(dp)
        status = (dp->di_bsddb->close)(dp->di_bsddb);
        BSDDB_END_SAVE(dp)
        if (status != 0) {
            dp->di_bsddb = NULL;
            PyErr_SetFromErrno(BsddbError);
            return NULL;
        }
    }
    dp->di_bsddb = NULL;
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
bsddb_keys(bsddbobject *dp)
{
    PyObject *list, *item=NULL;
    DBT krec, drec;
    char *data=NULL,buf[4096];
    int status;
    int err;

    check_bsddbobject_open(dp, NULL);
    list = PyList_New(0);
    if (list == NULL)
        return NULL;
    BSDDB_BGN_SAVE(dp)
    status = (dp->di_bsddb->seq)(dp->di_bsddb, &krec, &drec, R_FIRST);
    if (status == 0) {
        if (krec.size > sizeof(buf)) data = malloc(krec.size);
        else data = buf;
        if (data != NULL) memcpy(data,krec.data,krec.size);
    }
    BSDDB_END_SAVE(dp)
    if (status == 0 && data==NULL) return PyErr_NoMemory();
    while (status == 0) {
        if (dp->di_type == DB_RECNO)
            item = PyInt_FromLong(*((int*)data));
        else
            item = PyString_FromStringAndSize(data,
                                              (int)krec.size);
        if (data != buf) free(data);
        if (item == NULL) {
            Py_DECREF(list);
            return NULL;
        }
        err = PyList_Append(list, item);
        Py_DECREF(item);
        if (err != 0) {
            Py_DECREF(list);
            return NULL;
        }
        BSDDB_BGN_SAVE(dp)
        status = (dp->di_bsddb->seq)
            (dp->di_bsddb, &krec, &drec, R_NEXT);
        if (status == 0) {
            if (krec.size > sizeof(buf))
                data = malloc(krec.size);
            else data = buf;
            if (data != NULL)
                memcpy(data,krec.data,krec.size);
        }
        BSDDB_END_SAVE(dp)
        if (data == NULL) return PyErr_NoMemory();
    }
    if (status < 0) {
        PyErr_SetFromErrno(BsddbError);
        Py_DECREF(list);
        return NULL;
    }
    if (dp->di_size < 0)
        dp->di_size = PyList_Size(list); /* We just did the work */
    return list;
}

static PyObject *
bsddb_has_key(bsddbobject *dp, PyObject *args)
{
    DBT krec, drec;
    int status;
    char *data;
    int size;
    recno_t recno;

    if (dp->di_type == DB_RECNO) {
        if (!PyArg_ParseTuple(args, "i;key type must be integer",
                              &recno)) {
            return NULL;
        }
        krec.data = &recno;
        krec.size = sizeof(recno);
    }
    else {
        if (!PyArg_ParseTuple(args, "s#;key type must be string",
                              &data, &size)) {
            return NULL;
        }
        krec.data = data;
        krec.size = size;
    }
    check_bsddbobject_open(dp, NULL);

    BSDDB_BGN_SAVE(dp)
    status = (dp->di_bsddb->get)(dp->di_bsddb, &krec, &drec, 0);
    BSDDB_END_SAVE(dp)
    if (status < 0) {
        PyErr_SetFromErrno(BsddbError);
        return NULL;
    }

    return PyInt_FromLong(status == 0);
}

static PyObject *
bsddb_set_location(bsddbobject *dp, PyObject *key)
{
    int status;
    DBT krec, drec;
    char *data = NULL;
    char buf[4096];
    int size;
    PyObject *result;
    recno_t recno;

    if (dp->di_type == DB_RECNO) {
        if (!PyArg_ParseTuple(key, "i;key type must be integer",
                              &recno)) {
            return NULL;
        }
        krec.data = &recno;
        krec.size = sizeof(recno);
    }
    else {
        if (!PyArg_ParseTuple(key, "s#;key type must be string",
                              &data, &size)) {
            return NULL;
        }
        krec.data = data;
        krec.size = size;
    }
    check_bsddbobject_open(dp, NULL);

    BSDDB_BGN_SAVE(dp)
    status = (dp->di_bsddb->seq)(dp->di_bsddb, &krec, &drec, R_CURSOR);
    if (status == 0) {
        if (drec.size > sizeof(buf)) data = malloc(drec.size);
        else data = buf;
        if (data!=NULL) memcpy(data,drec.data,drec.size);
    }
    BSDDB_END_SAVE(dp)
    if (data==NULL) return PyErr_NoMemory();
    if (status != 0) {
        if (status < 0)
            PyErr_SetFromErrno(BsddbError);
        else
            PyErr_SetObject(PyExc_KeyError, key);
        return NULL;
    }

    if (dp->di_type == DB_RECNO)
        result = Py_BuildValue("is#", *((int*)krec.data),
                               data, drec.size);
    else
        result = Py_BuildValue("s#s#", krec.data, krec.size,
                               data, drec.size);
    if (data != buf) free(data);
    return result;
}

static PyObject *
bsddb_seq(bsddbobject *dp, int sequence_request)
{
    int status;
    DBT krec, drec;
    char *kdata=NULL,kbuf[4096];
    char *ddata=NULL,dbuf[4096];
    PyObject *result;

    check_bsddbobject_open(dp, NULL);
    krec.data = 0;
    krec.size = 0;

    BSDDB_BGN_SAVE(dp)
    status = (dp->di_bsddb->seq)(dp->di_bsddb, &krec,
                                 &drec, sequence_request);
    if (status == 0) {
        if (krec.size > sizeof(kbuf)) kdata = malloc(krec.size);
        else kdata = kbuf;
        if (kdata != NULL) memcpy(kdata,krec.data,krec.size);
        if (drec.size > sizeof(dbuf)) ddata = malloc(drec.size);
        else ddata = dbuf;
        if (ddata != NULL) memcpy(ddata,drec.data,drec.size);
    }
    BSDDB_END_SAVE(dp)
    if (status == 0) {
        if ((kdata == NULL) || (ddata == NULL))
            return PyErr_NoMemory();
    }
    else {
        /* (status != 0) */
        if (status < 0)
            PyErr_SetFromErrno(BsddbError);
        else
            PyErr_SetString(PyExc_KeyError, "no key/data pairs");
        return NULL;
    }

    if (dp->di_type == DB_RECNO)
        result = Py_BuildValue("is#", *((int*)kdata),
                               ddata, drec.size);
    else
        result = Py_BuildValue("s#s#", kdata, krec.size,
                               ddata, drec.size);
    if (kdata != kbuf) free(kdata);
    if (ddata != dbuf) free(ddata);
    return result;
}

static PyObject *
bsddb_next(bsddbobject *dp)
{
    return bsddb_seq(dp, R_NEXT);
}
static PyObject *
bsddb_previous(bsddbobject *dp)
{
    return bsddb_seq(dp, R_PREV);
}
static PyObject *
bsddb_first(bsddbobject *dp)
{
    return bsddb_seq(dp, R_FIRST);
}
static PyObject *
bsddb_last(bsddbobject *dp)
{
    return bsddb_seq(dp, R_LAST);
}
static PyObject *
bsddb_sync(bsddbobject *dp)
{
    int status;

    check_bsddbobject_open(dp, NULL);
    BSDDB_BGN_SAVE(dp)
    status = (dp->di_bsddb->sync)(dp->di_bsddb, 0);
    BSDDB_END_SAVE(dp)
    if (status != 0) {
        PyErr_SetFromErrno(BsddbError);
        return NULL;
    }
    return PyInt_FromLong(0);
}
static PyMethodDef bsddb_methods[] = {
    {"close",                   (PyCFunction)bsddb_close, METH_NOARGS},
    {"keys",                    (PyCFunction)bsddb_keys, METH_NOARGS},
    {"has_key",                 (PyCFunction)bsddb_has_key, METH_VARARGS},
    {"set_location",            (PyCFunction)bsddb_set_location, METH_VARARGS},
    {"next",                    (PyCFunction)bsddb_next, METH_NOARGS},
    {"previous",        (PyCFunction)bsddb_previous, METH_NOARGS},
    {"first",                   (PyCFunction)bsddb_first, METH_NOARGS},
    {"last",                    (PyCFunction)bsddb_last, METH_NOARGS},
    {"sync",                    (PyCFunction)bsddb_sync, METH_NOARGS},
    {NULL,              NULL}           /* sentinel */
};

static PyObject *
bsddb_getattr(PyObject *dp, char *name)
{
    return Py_FindMethod(bsddb_methods, dp, name);
}

static PyTypeObject Bsddbtype = {
    PyObject_HEAD_INIT(NULL)
    0,
    "bsddb.bsddb",
    sizeof(bsddbobject),
    0,
    (destructor)bsddb_dealloc, /*tp_dealloc*/
    0,                          /*tp_print*/
    (getattrfunc)bsddb_getattr, /*tp_getattr*/
    0,                          /*tp_setattr*/
    0,                          /*tp_compare*/
    0,                          /*tp_repr*/
    0,                          /*tp_as_number*/
    0,                          /*tp_as_sequence*/
    &bsddb_as_mapping,          /*tp_as_mapping*/
};

static PyObject *
bsdhashopen(PyObject *self, PyObject *args)
{
    char *file;
    char *flag = NULL;
    int flags = O_RDONLY;
    int mode = 0666;
    int bsize = 0;
    int ffactor = 0;
    int nelem = 0;
    int cachesize = 0;
    int hash = 0; /* XXX currently ignored */
    int lorder = 0;

    if (!PyArg_ParseTuple(args, "z|siiiiiii:hashopen",
                          &file, &flag, &mode,
                          &bsize, &ffactor, &nelem, &cachesize,
                          &hash, &lorder))
        return NULL;
    if (flag != NULL) {
        /* XXX need to pass O_EXCL, O_EXLOCK, O_NONBLOCK, O_SHLOCK */
        if (flag[0] == 'r')
            flags = O_RDONLY;
        else if (flag[0] == 'w')
            flags = O_RDWR;
        else if (flag[0] == 'c')
            flags = O_RDWR|O_CREAT;
        else if (flag[0] == 'n')
            flags = O_RDWR|O_CREAT|O_TRUNC;
        else {
            PyErr_SetString(BsddbError,
                "Flag should begin with 'r', 'w', 'c' or 'n'");
            return NULL;
        }
        if (flag[1] == 'l') {
#if defined(O_EXLOCK) && defined(O_SHLOCK)
            if (flag[0] == 'r')
                flags |= O_SHLOCK;
            else
                flags |= O_EXLOCK;
#else
            PyErr_SetString(BsddbError,
                         "locking not supported on this platform");
            return NULL;
#endif
        }
    }
    return newdbhashobject(file, flags, mode,
                           bsize, ffactor, nelem, cachesize, hash, lorder);
}

static PyObject *
bsdbtopen(PyObject *self, PyObject *args)
{
    char *file;
    char *flag = NULL;
    int flags = O_RDONLY;
    int mode = 0666;
    int cachesize = 0;
    int maxkeypage = 0;
    int minkeypage = 0;
    int btflags = 0;
    unsigned int psize = 0;
    int lorder = 0;

    if (!PyArg_ParseTuple(args, "z|siiiiiii:btopen",
                          &file, &flag, &mode,
                          &btflags, &cachesize, &maxkeypage, &minkeypage,
                          &psize, &lorder))
        return NULL;
    if (flag != NULL) {
        /* XXX need to pass O_EXCL, O_EXLOCK, O_NONBLOCK, O_SHLOCK */
        if (flag[0] == 'r')
            flags = O_RDONLY;
        else if (flag[0] == 'w')
            flags = O_RDWR;
        else if (flag[0] == 'c')
            flags = O_RDWR|O_CREAT;
        else if (flag[0] == 'n')
            flags = O_RDWR|O_CREAT|O_TRUNC;
        else {
            PyErr_SetString(BsddbError,
                   "Flag should begin with 'r', 'w', 'c' or 'n'");
            return NULL;
        }
        if (flag[1] == 'l') {
#if defined(O_EXLOCK) && defined(O_SHLOCK)
            if (flag[0] == 'r')
                flags |= O_SHLOCK;
            else
                flags |= O_EXLOCK;
#else
            PyErr_SetString(BsddbError,
                        "locking not supported on this platform");
            return NULL;
#endif
        }
    }
    return newdbbtobject(file, flags, mode,
                         btflags, cachesize, maxkeypage, minkeypage,
                         psize, lorder);
}

static PyObject *
bsdrnopen(PyObject *self, PyObject *args)
{
    char *file;
    char *flag = NULL;
    int flags = O_RDONLY;
    int mode = 0666;
    int cachesize = 0;
    int rnflags = 0;
    unsigned int psize = 0;
    int lorder = 0;
    size_t reclen = 0;
    char  *bval = "";
    char *bfname = NULL;

    if (!PyArg_ParseTuple(args, "z|siiiiiiss:rnopen",
                          &file, &flag, &mode,
                          &rnflags, &cachesize, &psize, &lorder,
                          &reclen, &bval, &bfname))
        return NULL;

    if (flag != NULL) {
        /* XXX need to pass O_EXCL, O_EXLOCK, O_NONBLOCK, O_SHLOCK */
        if (flag[0] == 'r')
            flags = O_RDONLY;
        else if (flag[0] == 'w')
            flags = O_RDWR;
        else if (flag[0] == 'c')
            flags = O_RDWR|O_CREAT;
        else if (flag[0] == 'n')
            flags = O_RDWR|O_CREAT|O_TRUNC;
        else {
            PyErr_SetString(BsddbError,
                   "Flag should begin with 'r', 'w', 'c' or 'n'");
            return NULL;
        }
        if (flag[1] == 'l') {
#if defined(O_EXLOCK) && defined(O_SHLOCK)
            if (flag[0] == 'r')
                flags |= O_SHLOCK;
            else
                flags |= O_EXLOCK;
#else
            PyErr_SetString(BsddbError,
                        "locking not supported on this platform");
            return NULL;
#endif
        }
        else if (flag[1] != '\0') {
            PyErr_SetString(BsddbError,
                           "Flag char 2 should be 'l' or absent");
            return NULL;
        }
    }
    return newdbrnobject(file, flags, mode, rnflags, cachesize,
                         psize, lorder, reclen, bval[0], bfname);
}

static PyMethodDef bsddbmodule_methods[] = {
    {"hashopen",        (PyCFunction)bsdhashopen, METH_VARARGS},
    {"btopen",          (PyCFunction)bsdbtopen, METH_VARARGS},
    {"rnopen",          (PyCFunction)bsdrnopen, METH_VARARGS},
    /* strictly for use by dbhhash!!! */
    {"open",            (PyCFunction)bsdhashopen, METH_VARARGS},
    {0,                 0},
};

PyMODINIT_FUNC
initbsddb185(void) {
    PyObject *m, *d;

    if (PyErr_WarnPy3k("the bsddb185 module has been removed in "
                       "Python 3.0", 2) < 0)
    return;

    Bsddbtype.ob_type = &PyType_Type;
    m = Py_InitModule("bsddb185", bsddbmodule_methods);
    if (m == NULL)
        return;
    d = PyModule_GetDict(m);
    BsddbError = PyErr_NewException("bsddb.error", NULL, NULL);
    if (BsddbError != NULL)
        PyDict_SetItemString(d, "error", BsddbError);
}