/*----------------------------------------------------------------------

Copyright (c) 1999-2001, Digital Creations, Fredericksburg, VA, USA

and Andrew Kuchling. All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are

met:

o Redistributions of source code must retain the above copyright

notice, this list of conditions, and the disclaimer that follows.

o Redistributions in binary form must reproduce the above copyright

notice, this list of conditions, and the following disclaimer in

the documentation and/or other materials provided with the

distribution.

o Neither the name of Digital Creations nor the names of its

contributors may be used to endorse or promote products derived

from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY DIGITAL CREATIONS AND CONTRIBUTORS *AS

IS* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED

TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DIGITAL

CREATIONS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,

BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS

OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR

TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE

USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH

DAMAGE.

------------------------------------------------------------------------*/

/*

* Handwritten code to wrap version 3.x of the Berkeley DB library,

* written to replace a SWIG-generated file. It has since been updated

* to compile with BerkeleyDB versions 3.2 through 4.2.

*

* This module was started by Andrew Kuchling to remove the dependency

* on SWIG in a package by Gregory P. Smith <[email protected]> who

* based his work on a similar package by Robin Dunn <[email protected]>

* which wrapped Berkeley DB 2.7.x.

*

* Development of this module then returned full circle back to Robin Dunn

* who worked on behalf of Digital Creations to complete the wrapping of

* the DB 3.x API and to build a solid unit test suite. Robin has

* since gone onto other projects (wxPython).

*

* Gregory P. Smith <[email protected]> is once again the maintainer.

*

* Use the [email protected] mailing list for all questions.

* Things can change faster than the header of this file is updated. This

* file is shared with the PyBSDDB project at SourceForge:

*

* http://pybsddb.sf.net

*

* This file should remain backward compatible with Python 2.1, but see PEP

* 291 for the most current backward compatibility requirements:

*

* http://www.python.org/peps/pep-0291.html

*

* This module contains 5 types:

*

* DB (Database)

* DBCursor (Database Cursor)

* DBEnv (database environment)

* DBTxn (An explicit database transaction)

* DBLock (A lock handle)

*

*/

/* --------------------------------------------------------------------- */

/*

* Portions of this module, associated unit tests and build scripts are the

* result of a contract with The Written Word (http://thewrittenword.com/)

* Many thanks go out to them for causing me to raise the bar on quality and

* functionality, resulting in a better bsddb3 package for all of us to use.

*

* --Robin

*/

/* --------------------------------------------------------------------- */

#include <stddef.h> /* for offsetof() */

#include <Python.h>

#include <db.h>

/* --------------------------------------------------------------------- */

/* Various macro definitions */

/* 40 = 4.0, 33 = 3.3; this will break if the second number is > 9 */

#define DBVER (DB_VERSION_MAJOR * 10 + DB_VERSION_MINOR)

#if DB_VERSION_MINOR > 9

#error "eek! DBVER can't handle minor versions > 9"

#endif

#define PY_BSDDB_VERSION "4.2.9"

static char *rcs_id = "$Id$";

#ifdef WITH_THREAD

/* These are for when calling Python --> C */

#define MYDB_BEGIN_ALLOW_THREADS Py_BEGIN_ALLOW_THREADS;

#define MYDB_END_ALLOW_THREADS Py_END_ALLOW_THREADS;

/* For 2.3, use the PyGILState_ calls */

#if (PY_VERSION_HEX >= 0x02030000)

#define MYDB_USE_GILSTATE

#endif

/* and these are for calling C --> Python */

#if defined(MYDB_USE_GILSTATE)

#define MYDB_BEGIN_BLOCK_THREADS \

PyGILState_STATE __savestate = PyGILState_Ensure();

#define MYDB_END_BLOCK_THREADS \

PyGILState_Release(__savestate);

#else /* MYDB_USE_GILSTATE */

/* Pre GILState API - do it the long old way */

static PyInterpreterState* _db_interpreterState = NULL;

#define MYDB_BEGIN_BLOCK_THREADS { \

PyThreadState* prevState; \

PyThreadState* newState; \

PyEval_AcquireLock(); \

newState = PyThreadState_New(_db_interpreterState); \

prevState = PyThreadState_Swap(newState);

#define MYDB_END_BLOCK_THREADS \

newState = PyThreadState_Swap(prevState); \

PyThreadState_Clear(newState); \

PyEval_ReleaseLock(); \

PyThreadState_Delete(newState); \

}

#endif /* MYDB_USE_GILSTATE */

#else

/* Compiled without threads - avoid all this cruft */

#define MYDB_BEGIN_ALLOW_THREADS

#define MYDB_END_ALLOW_THREADS

#define MYDB_BEGIN_BLOCK_THREADS

#define MYDB_END_BLOCK_THREADS

#endif

/* Should DB_INCOMPLETE be turned into a warning or an exception? */

#define INCOMPLETE_IS_WARNING 1

/* --------------------------------------------------------------------- */

/* Exceptions */

static PyObject* DBError; /* Base class, all others derive from this */

static PyObject* DBCursorClosedError; /* raised when trying to use a closed cursor object */

static PyObject* DBKeyEmptyError; /* DB_KEYEMPTY */

static PyObject* DBKeyExistError; /* DB_KEYEXIST */

static PyObject* DBLockDeadlockError; /* DB_LOCK_DEADLOCK */

static PyObject* DBLockNotGrantedError; /* DB_LOCK_NOTGRANTED */

static PyObject* DBNotFoundError; /* DB_NOTFOUND: also derives from KeyError */

static PyObject* DBOldVersionError; /* DB_OLD_VERSION */

static PyObject* DBRunRecoveryError; /* DB_RUNRECOVERY */

static PyObject* DBVerifyBadError; /* DB_VERIFY_BAD */

static PyObject* DBNoServerError; /* DB_NOSERVER */

static PyObject* DBNoServerHomeError; /* DB_NOSERVER_HOME */

static PyObject* DBNoServerIDError; /* DB_NOSERVER_ID */

#if (DBVER >= 33)

static PyObject* DBPageNotFoundError; /* DB_PAGE_NOTFOUND */

static PyObject* DBSecondaryBadError; /* DB_SECONDARY_BAD */

#endif

#if !INCOMPLETE_IS_WARNING

static PyObject* DBIncompleteError; /* DB_INCOMPLETE */

#endif

static PyObject* DBInvalidArgError; /* EINVAL */

static PyObject* DBAccessError; /* EACCES */

static PyObject* DBNoSpaceError; /* ENOSPC */

static PyObject* DBNoMemoryError; /* ENOMEM */

static PyObject* DBAgainError; /* EAGAIN */

static PyObject* DBBusyError; /* EBUSY */

static PyObject* DBFileExistsError; /* EEXIST */

static PyObject* DBNoSuchFileError; /* ENOENT */

static PyObject* DBPermissionsError; /* EPERM */

/* --------------------------------------------------------------------- */

/* Structure definitions */

#if PYTHON_API_VERSION >= 1010 /* python >= 2.1 support weak references */

#define HAVE_WEAKREF

#else

#undef HAVE_WEAKREF

#endif

/* if Python >= 2.1 better support warnings */

#if PYTHON_API_VERSION >= 1010

#define HAVE_WARNINGS

#else

#undef HAVE_WARNINGS

#endif

#if PYTHON_API_VERSION <= 1007

/* 1.5 compatibility */

#define PyObject_New PyObject_NEW

#define PyObject_Del PyMem_DEL

#endif

struct behaviourFlags {

/* What is the default behaviour when DB->get or DBCursor->get returns a

DB_NOTFOUND error? Return None or raise an exception? */

unsigned int getReturnsNone : 1;

/* What is the default behaviour for DBCursor.set* methods when DBCursor->get

* returns a DB_NOTFOUND error? Return None or raise an exception? */

unsigned int cursorSetReturnsNone : 1;

};

#define DEFAULT_GET_RETURNS_NONE 1

#define DEFAULT_CURSOR_SET_RETURNS_NONE 1 /* 0 in pybsddb < 4.2, python < 2.4 */

typedef struct {

PyObject_HEAD

DB_ENV* db_env;

u_int32_t flags; /* saved flags from open() */

int closed;

struct behaviourFlags moduleFlags;

#ifdef HAVE_WEAKREF

PyObject *in_weakreflist; /* List of weak references */

#endif

} DBEnvObject;

typedef struct {

PyObject_HEAD

DB* db;

DBEnvObject* myenvobj; /* PyObject containing the DB_ENV */

u_int32_t flags; /* saved flags from open() */

u_int32_t setflags; /* saved flags from set_flags() */

int haveStat;

struct behaviourFlags moduleFlags;

#if (DBVER >= 33)

PyObject* associateCallback;

int primaryDBType;

#endif

#ifdef HAVE_WEAKREF

PyObject *in_weakreflist; /* List of weak references */

#endif

} DBObject;

typedef struct {

PyObject_HEAD

DBC* dbc;

DBObject* mydb;

#ifdef HAVE_WEAKREF

PyObject *in_weakreflist; /* List of weak references */

#endif

} DBCursorObject;

typedef struct {

PyObject_HEAD

DB_TXN* txn;

#ifdef HAVE_WEAKREF

PyObject *in_weakreflist; /* List of weak references */

#endif

} DBTxnObject;

typedef struct {

PyObject_HEAD

DB_LOCK lock;

#ifdef HAVE_WEAKREF

PyObject *in_weakreflist; /* List of weak references */

#endif

} DBLockObject;

staticforward PyTypeObject DB_Type, DBCursor_Type, DBEnv_Type, DBTxn_Type, DBLock_Type;

#define DBObject_Check(v) ((v)->ob_type == &DB_Type)

#define DBCursorObject_Check(v) ((v)->ob_type == &DBCursor_Type)

#define DBEnvObject_Check(v) ((v)->ob_type == &DBEnv_Type)

#define DBTxnObject_Check(v) ((v)->ob_type == &DBTxn_Type)

#define DBLockObject_Check(v) ((v)->ob_type == &DBLock_Type)

/* --------------------------------------------------------------------- */

/* Utility macros and functions */

#define RETURN_IF_ERR() \

if (makeDBError(err)) { \

return NULL; \

}

#define RETURN_NONE() Py_INCREF(Py_None); return Py_None;

#define _CHECK_OBJECT_NOT_CLOSED(nonNull, pyErrObj, name) \

if ((nonNull) == NULL) { \

PyObject *errTuple = NULL; \

errTuple = Py_BuildValue("(is)", 0, #name " object has been closed"); \

PyErr_SetObject((pyErrObj), errTuple); \

Py_DECREF(errTuple); \

return NULL; \

}

#define CHECK_DB_NOT_CLOSED(dbobj) \

_CHECK_OBJECT_NOT_CLOSED(dbobj->db, DBError, DB)

#define CHECK_ENV_NOT_CLOSED(env) \

_CHECK_OBJECT_NOT_CLOSED(env->db_env, DBError, DBEnv)

#define CHECK_CURSOR_NOT_CLOSED(curs) \

_CHECK_OBJECT_NOT_CLOSED(curs->dbc, DBCursorClosedError, DBCursor)

#define CHECK_DBFLAG(mydb, flag) (((mydb)->flags & (flag)) || \

(((mydb)->myenvobj != NULL) && ((mydb)->myenvobj->flags & (flag))))

#define CLEAR_DBT(dbt) (memset(&(dbt), 0, sizeof(dbt)))

#define FREE_DBT(dbt) if ((dbt.flags & (DB_DBT_MALLOC|DB_DBT_REALLOC)) && \

dbt.data != NULL) { free(dbt.data); dbt.data = NULL; }

static int makeDBError(int err);

/* Return the access method type of the DBObject */

static int _DB_get_type(DBObject* self)

{

#if (DBVER >= 33)

DBTYPE type;

int err;

err = self->db->get_type(self->db, &type);

if (makeDBError(err)) {

return -1;

}

return type;

#else

return self->db->get_type(self->db);

#endif

}

/* Create a DBT structure (containing key and data values) from Python

strings. Returns 1 on success, 0 on an error. */

static int make_dbt(PyObject* obj, DBT* dbt)

{

CLEAR_DBT(*dbt);

if (obj == Py_None) {

/* no need to do anything, the structure has already been zeroed */

}

else if (!PyArg_Parse(obj, "s#", &dbt->data, &dbt->size)) {

PyErr_SetString(PyExc_TypeError,

"Data values must be of type string or None.");

return 0;

}

return 1;

}

/* Recno and Queue DBs can have integer keys. This function figures out

what's been given, verifies that it's allowed, and then makes the DBT.

Caller MUST call FREE_DBT(key) when done. */

static int

make_key_dbt(DBObject* self, PyObject* keyobj, DBT* key, int* pflags)

{

db_recno_t recno;

int type;

CLEAR_DBT(*key);

if (keyobj == Py_None) {

type = _DB_get_type(self);

if (type == -1)

return 0;

if (type == DB_RECNO || type == DB_QUEUE) {

PyErr_SetString(

PyExc_TypeError,

"None keys not allowed for Recno and Queue DB's");

return 0;

}

/* no need to do anything, the structure has already been zeroed */

}

else if (PyString_Check(keyobj)) {

/* verify access method type */

type = _DB_get_type(self);

if (type == -1)

return 0;

if (type == DB_RECNO || type == DB_QUEUE) {

PyErr_SetString(

PyExc_TypeError,

"String keys not allowed for Recno and Queue DB's");

return 0;

}

key->data = PyString_AS_STRING(keyobj);

key->size = PyString_GET_SIZE(keyobj);

}

else if (PyInt_Check(keyobj)) {

/* verify access method type */

type = _DB_get_type(self);

if (type == -1)

return 0;

if (type == DB_BTREE && pflags != NULL) {

/* if BTREE then an Integer key is allowed with the

* DB_SET_RECNO flag */

*pflags |= DB_SET_RECNO;

}

else if (type != DB_RECNO && type != DB_QUEUE) {

PyErr_SetString(

PyExc_TypeError,

"Integer keys only allowed for Recno and Queue DB's");

return 0;

}

/* Make a key out of the requested recno, use allocated space so DB

* will be able to realloc room for the real key if needed. */

recno = PyInt_AS_LONG(keyobj);

key->data = malloc(sizeof(db_recno_t));

if (key->data == NULL) {

PyErr_SetString(PyExc_MemoryError, "Key memory allocation failed");

return 0;

}

key->ulen = key->size = sizeof(db_recno_t);

memcpy(key->data, &recno, sizeof(db_recno_t));

key->flags = DB_DBT_REALLOC;

}

else {

PyErr_Format(PyExc_TypeError,

"String or Integer object expected for key, %s found",

keyobj->ob_type->tp_name);

return 0;

}

return 1;

}

/* Add partial record access to an existing DBT data struct.

If dlen and doff are set, then the DB_DBT_PARTIAL flag will be set

and the data storage/retrieval will be done using dlen and doff. */

static int add_partial_dbt(DBT* d, int dlen, int doff) {

/* if neither were set we do nothing (-1 is the default value) */

if ((dlen == -1) && (doff == -1)) {

return 1;

}

if ((dlen < 0) || (doff < 0)) {

PyErr_SetString(PyExc_TypeError, "dlen and doff must both be >= 0");

return 0;

}

d->flags = d->flags | DB_DBT_PARTIAL;

d->dlen = (unsigned int) dlen;

d->doff = (unsigned int) doff;

return 1;

}

/* Callback used to save away more information about errors from the DB

* library. */

static char _db_errmsg[1024];

static void _db_errorCallback(const char* prefix, char* msg)

{

strcpy(_db_errmsg, msg);

}

/* make a nice exception object to raise for errors. */

static int makeDBError(int err)

{

char errTxt[2048]; /* really big, just in case... */

PyObject *errObj = NULL;

PyObject *errTuple = NULL;

int exceptionRaised = 0;

switch (err) {

case 0: /* successful, no error */ break;

#if (DBVER < 41)

case DB_INCOMPLETE:

#if INCOMPLETE_IS_WARNING

strcpy(errTxt, db_strerror(err));

if (_db_errmsg[0]) {

strcat(errTxt, " -- ");

strcat(errTxt, _db_errmsg);

_db_errmsg[0] = 0;

}

#ifdef HAVE_WARNINGS

exceptionRaised = PyErr_Warn(PyExc_RuntimeWarning, errTxt);

#else

fprintf(stderr, errTxt);

fprintf(stderr, "\n");

#endif

#else /* do an exception instead */

errObj = DBIncompleteError;

#endif

break;

#endif /* DBVER < 41 */

case DB_KEYEMPTY: errObj = DBKeyEmptyError; break;

case DB_KEYEXIST: errObj = DBKeyExistError; break;

case DB_LOCK_DEADLOCK: errObj = DBLockDeadlockError; break;

case DB_LOCK_NOTGRANTED: errObj = DBLockNotGrantedError; break;

case DB_NOTFOUND: errObj = DBNotFoundError; break;

case DB_OLD_VERSION: errObj = DBOldVersionError; break;

case DB_RUNRECOVERY: errObj = DBRunRecoveryError; break;

case DB_VERIFY_BAD: errObj = DBVerifyBadError; break;

case DB_NOSERVER: errObj = DBNoServerError; break;

case DB_NOSERVER_HOME: errObj = DBNoServerHomeError; break;

case DB_NOSERVER_ID: errObj = DBNoServerIDError; break;

#if (DBVER >= 33)

case DB_PAGE_NOTFOUND: errObj = DBPageNotFoundError; break;

case DB_SECONDARY_BAD: errObj = DBSecondaryBadError; break;

#endif

case EINVAL: errObj = DBInvalidArgError; break;

case EACCES: errObj = DBAccessError; break;

case ENOSPC: errObj = DBNoSpaceError; break;

case ENOMEM: errObj = DBNoMemoryError; break;

case EAGAIN: errObj = DBAgainError; break;

case EBUSY : errObj = DBBusyError; break;

case EEXIST: errObj = DBFileExistsError; break;

case ENOENT: errObj = DBNoSuchFileError; break;

case EPERM : errObj = DBPermissionsError; break;

default: errObj = DBError; break;

}

if (errObj != NULL) {

/* FIXME this needs proper bounds checking on errTxt */

strcpy(errTxt, db_strerror(err));

if (_db_errmsg[0]) {

strcat(errTxt, " -- ");

strcat(errTxt, _db_errmsg);

_db_errmsg[0] = 0;

}

errTuple = Py_BuildValue("(is)", err, errTxt);

PyErr_SetObject(errObj, errTuple);

Py_DECREF(errTuple);

}

return ((errObj != NULL) || exceptionRaised);

}

/* set a type exception */

static void makeTypeError(char* expected, PyObject* found)

{

PyErr_Format(PyExc_TypeError, "Expected %s argument, %s found.",

expected, found->ob_type->tp_name);

}

/* verify that an obj is either None or a DBTxn, and set the txn pointer */

static int checkTxnObj(PyObject* txnobj, DB_TXN** txn)

{

if (txnobj == Py_None || txnobj == NULL) {

*txn = NULL;

return 1;

}

if (DBTxnObject_Check(txnobj)) {

*txn = ((DBTxnObject*)txnobj)->txn;

return 1;

}

else

makeTypeError("DBTxn", txnobj);

return 0;

}

/* Delete a key from a database

Returns 0 on success, -1 on an error. */

static int _DB_delete(DBObject* self, DB_TXN *txn, DBT *key, int flags)

{

int err;

MYDB_BEGIN_ALLOW_THREADS;

err = self->db->del(self->db, txn, key, 0);

MYDB_END_ALLOW_THREADS;

if (makeDBError(err)) {

return -1;

}

self->haveStat = 0;

return 0;

}

/* Store a key into a database

Returns 0 on success, -1 on an error. */

static int _DB_put(DBObject* self, DB_TXN *txn, DBT *key, DBT *data, int flags)

{

int err;

MYDB_BEGIN_ALLOW_THREADS;

err = self->db->put(self->db, txn, key, data, flags);

MYDB_END_ALLOW_THREADS;

if (makeDBError(err)) {

return -1;

}

self->haveStat = 0;

return 0;

}

/* Get a key/data pair from a cursor */

static PyObject* _DBCursor_get(DBCursorObject* self, int extra_flags,

PyObject *args, PyObject *kwargs, char *format)

{

int err;

PyObject* retval = NULL;

DBT key, data;

int dlen = -1;

int doff = -1;

int flags = 0;

char* kwnames[] = { "flags", "dlen", "doff", NULL };

if (!PyArg_ParseTupleAndKeywords(args, kwargs, format, kwnames,

&flags, &dlen, &doff))

return NULL;

CHECK_CURSOR_NOT_CLOSED(self);

flags |= extra_flags;

CLEAR_DBT(key);

CLEAR_DBT(data);

if (CHECK_DBFLAG(self->mydb, DB_THREAD)) {

/* Tell BerkeleyDB to malloc the return value (thread safe) */

data.flags = DB_DBT_MALLOC;

key.flags = DB_DBT_MALLOC;

}

if (!add_partial_dbt(&data, dlen, doff))

return NULL;

MYDB_BEGIN_ALLOW_THREADS;

err = self->dbc->c_get(self->dbc, &key, &data, flags);

MYDB_END_ALLOW_THREADS;

if ((err == DB_NOTFOUND) && self->mydb->moduleFlags.getReturnsNone) {

Py_INCREF(Py_None);

retval = Py_None;

}

else if (makeDBError(err)) {

retval = NULL;

}

else { /* otherwise, success! */

/* if Recno or Queue, return the key as an Int */

switch (_DB_get_type(self->mydb)) {

case -1:

retval = NULL;

break;

case DB_RECNO:

case DB_QUEUE:

retval = Py_BuildValue("is#", *((db_recno_t*)key.data),

data.data, data.size);

break;

case DB_HASH:

case DB_BTREE:

default:

retval = Py_BuildValue("s#s#", key.data, key.size,

data.data, data.size);

break;

}

}

if (!err) {

FREE_DBT(key);

FREE_DBT(data);

}

return retval;

}

/* add an integer to a dictionary using the given name as a key */

static void _addIntToDict(PyObject* dict, char *name, int value)

{

PyObject* v = PyInt_FromLong((long) value);

if (!v || PyDict_SetItemString(dict, name, v))

PyErr_Clear();

Py_XDECREF(v);

}

/* --------------------------------------------------------------------- */

/* Allocators and deallocators */

static DBObject*

newDBObject(DBEnvObject* arg, int flags)

{

DBObject* self;

DB_ENV* db_env = NULL;

int err;

self = PyObject_New(DBObject, &DB_Type);

if (self == NULL)

return NULL;

self->haveStat = 0;

self->flags = 0;

self->setflags = 0;

self->myenvobj = NULL;

#if (DBVER >= 33)

self->associateCallback = NULL;

self->primaryDBType = 0;

#endif

#ifdef HAVE_WEAKREF

self->in_weakreflist = NULL;

#endif

/* keep a reference to our python DBEnv object */

if (arg) {

Py_INCREF(arg);

self->myenvobj = arg;

db_env = arg->db_env;

}

if (self->myenvobj)

self->moduleFlags = self->myenvobj->moduleFlags;

else

self->moduleFlags.getReturnsNone = DEFAULT_GET_RETURNS_NONE;

self->moduleFlags.cursorSetReturnsNone = DEFAULT_CURSOR_SET_RETURNS_NONE;

MYDB_BEGIN_ALLOW_THREADS;

err = db_create(&self->db, db_env, flags);

self->db->set_errcall(self->db, _db_errorCallback);

#if (DBVER >= 33)

self->db->app_private = (void*)self;

#endif

MYDB_END_ALLOW_THREADS;

/* TODO add a weakref(self) to the self->myenvobj->open_child_weakrefs

* list so that a DBEnv can refuse to close without aborting any open

* open DBTxns and closing any open DBs first. */

if (makeDBError(err)) {

if (self->myenvobj) {

Py_DECREF(self->myenvobj);

self->myenvobj = NULL;

}

self = NULL;

}

return self;

}

static void

DB_dealloc(DBObject* self)

{

if (self->db != NULL) {

/* avoid closing a DB when its DBEnv has been closed out from under

* it */

if (!self->myenvobj ||

(self->myenvobj && self->myenvobj->db_env))

{

MYDB_BEGIN_ALLOW_THREADS;

self->db->close(self->db, 0);

MYDB_END_ALLOW_THREADS;

#ifdef HAVE_WARNINGS

} else {

PyErr_Warn(PyExc_RuntimeWarning,

"DB could not be closed in destructor: DBEnv already closed");

#endif

}

self->db = NULL;

}

#ifdef HAVE_WEAKREF

if (self->in_weakreflist != NULL) {

PyObject_ClearWeakRefs((PyObject *) self);

}

#endif

if (self->myenvobj) {

Py_DECREF(self->myenvobj);

self->myenvobj = NULL;

}

#if (DBVER >= 33)

if (self->associateCallback != NULL) {

Py_DECREF(self->associateCallback);

self->associateCallback = NULL;

}

#endif

PyObject_Del(self);

}

static DBCursorObject*

newDBCursorObject(DBC* dbc, DBObject* db)

{

DBCursorObject* self = PyObject_New(DBCursorObject, &DBCursor_Type);

if (self == NULL)

return NULL;

self->dbc = dbc;

self->mydb = db;

#ifdef HAVE_WEAKREF

self->in_weakreflist = NULL;

#endif

Py_INCREF(self->mydb);

return self;

}

static void

DBCursor_dealloc(DBCursorObject* self)

{

int err;

#ifdef HAVE_WEAKREF

if (self->in_weakreflist != NULL) {

PyObject_ClearWeakRefs((PyObject *) self);

}

#endif

if (self->dbc != NULL) {

MYDB_BEGIN_ALLOW_THREADS;

/* If the underlying database has been closed, we don't

need to do anything. If the environment has been closed

we need to leak, as BerkeleyDB will crash trying to access

the environment. There was an exception when the

user closed the environment even though there still was

a database open. */

if (self->mydb->db && self->mydb->myenvobj &&

!self->mydb->myenvobj->closed)

err = self->dbc->c_close(self->dbc);

self->dbc = NULL;

MYDB_END_ALLOW_THREADS;

}

Py_XDECREF( self->mydb );

PyObject_Del(self);

}

static DBEnvObject*

newDBEnvObject(int flags)

{

int err;

DBEnvObject* self = PyObject_New(DBEnvObject, &DBEnv_Type);

if (self == NULL)

return NULL;

self->closed = 1;

self->flags = flags;

self->moduleFlags.getReturnsNone = DEFAULT_GET_RETURNS_NONE;

self->moduleFlags.cursorSetReturnsNone = DEFAULT_CURSOR_SET_RETURNS_NONE;

#ifdef HAVE_WEAKREF

self->in_weakreflist = NULL;

#endif

MYDB_BEGIN_ALLOW_THREADS;

err = db_env_create(&self->db_env, flags);

MYDB_END_ALLOW_THREADS;

if (makeDBError(err)) {

self = NULL;

}

else {

self->db_env->set_errcall(self->db_env, _db_errorCallback);

}

return self;

}

static void

DBEnv_dealloc(DBEnvObject* self)

{

#ifdef HAVE_WEAKREF

if (self->in_weakreflist != NULL) {

PyObject_ClearWeakRefs((PyObject *) self);

}

#endif

if (self->db_env) {

MYDB_BEGIN_ALLOW_THREADS;

self->db_env->close(self->db_env, 0);

MYDB_END_ALLOW_THREADS;

}

PyObject_Del(self);

}

static DBTxnObject*

newDBTxnObject(DBEnvObject* myenv, DB_TXN *parent, int flags)

{

int err;

DBTxnObject* self = PyObject_New(DBTxnObject, &DBTxn_Type);

if (self == NULL)

return NULL;

#ifdef HAVE_WEAKREF

self->in_weakreflist = NULL;

#endif

MYDB_BEGIN_ALLOW_THREADS;

#if (DBVER >= 40)

err = myenv->db_env->txn_begin(myenv->db_env, parent, &(self->txn), flags);

#else

err = txn_begin(myenv->db_env, parent, &(self->txn), flags);

#endif

/* TODO add a weakref(self) to the self->myenvobj->open_child_weakrefs

* list so that a DBEnv can refuse to close without aborting any open

* open DBTxns and closing any open DBs first. */

MYDB_END_ALLOW_THREADS;

if (makeDBError(err)) {

self = NULL;

}

return self;

}

static void

DBTxn_dealloc(DBTxnObject* self)

{

#ifdef HAVE_WEAKREF

if (self->in_weakreflist != NULL) {

PyObject_ClearWeakRefs((PyObject *) self);

}

#endif

#ifdef HAVE_WARNINGS

if (self->txn) {

/* it hasn't been finalized, abort it! */

MYDB_BEGIN_ALLOW_THREADS;

#if (DBVER >= 40)

self->txn->abort(self->txn);

#else

txn_abort(self->txn);

#endif

MYDB_END_ALLOW_THREADS;

PyErr_Warn(PyExc_RuntimeWarning,

"DBTxn aborted in destructor. No prior commit() or abort().");

}

#endif

PyObject_Del(self);

}

static DBLockObject*

newDBLockObject(DBEnvObject* myenv, u_int32_t locker, DBT* obj,

db_lockmode_t lock_mode, int flags)

{

int err;

DBLockObject* self = PyObject_New(DBLockObject, &DBLock_Type);

if (self == NULL)

return NULL;

#ifdef HAVE_WEAKREF

self->in_weakreflist = NULL;

#endif

MYDB_BEGIN_ALLOW_THREADS;

#if (DBVER >= 40)

err = myenv->db_env->lock_get(myenv->db_env, locker, flags, obj, lock_mode,

&self->lock);

#else

err = lock_get(myenv->db_env, locker, flags, obj, lock_mode, &self->lock);

#endif

MYDB_END_ALLOW_THREADS;

if (makeDBError(err)) {

self = NULL;

}

return self;

}

static void

DBLock_dealloc(DBLockObject* self)

{

#ifdef HAVE_WEAKREF

if (self->in_weakreflist != NULL) {

PyObject_ClearWeakRefs((PyObject *) self);

}

#endif

/* TODO: is this lock held? should we release it? */

PyObject_Del(self);

}

/* --------------------------------------------------------------------- */

/* DB methods */

static PyObject*

DB_append(DBObject* self, PyObject* args)

{

PyObject* txnobj = NULL;

PyObject* dataobj;

db_recno_t recno;

DBT key, data;

DB_TXN *txn = NULL;

if (!PyArg_ParseTuple(args, "O|O:append", &dataobj, &txnobj))

return NULL;