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

  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 Berkeley DB 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 who based his work on a

 * similar package by Robin Dunn <robin@alldunn.com> 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 <greg@krypto.org> was once again the maintainer.

 *

 * Since January 2008, new maintainer is Jesus Cea <jcea@jcea.es>.

 * Jesus Cea licenses this code to PSF under a Contributor Agreement.

 *

 * Use the pybsddb-users@lists.sf.net 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 6 types:

 *

 * DB           (Database)

 * DBCursor     (Database Cursor)

 * DBEnv        (database environment)

 * DBTxn        (An explicit database transaction)

 * DBLock       (A lock handle)

 * DBSequence   (Sequence)

 *

 */

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

/*

 * 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>

#define COMPILING_BSDDB_C

#include "bsddb.h"

#undef COMPILING_BSDDB_C

static char *rcs_id = "$Id: _bsddb.c 66568 2008-09-23 18:54:08Z jesus.cea $";

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

/* Various macro definitions */

#if (PY_VERSION_HEX < 0x02050000)

typedef int Py_ssize_t;

#endif

#if (PY_VERSION_HEX < 0x02060000)  /* really: before python trunk r63675 */

/* This code now uses PyBytes* API function names instead of PyString*.

 * These #defines map to their equivalent on earlier python versions.    */

#define PyBytes_FromStringAndSize PyString_FromStringAndSize

#define PyBytes_FromString PyString_FromString

#define PyBytes_AsStringAndSize PyString_AsStringAndSize

#define PyBytes_Check PyString_Check

#define PyBytes_GET_SIZE PyString_GET_SIZE

#define PyBytes_AS_STRING PyString_AS_STRING

#endif

#if (PY_VERSION_HEX >= 0x03000000)

#define NUMBER_Check    PyLong_Check

#define NUMBER_AsLong   PyLong_AsLong

#define NUMBER_FromLong PyLong_FromLong

#else

#define NUMBER_Check    PyInt_Check

#define NUMBER_AsLong   PyInt_AsLong

#define NUMBER_FromLong PyInt_FromLong

#endif

#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: also derives from KeyError */

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 */

static PyObject* DBPageNotFoundError;   /* DB_PAGE_NOTFOUND */

static PyObject* DBSecondaryBadError;   /* DB_SECONDARY_BAD */

#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;       /* DB_BUFFER_SMALL (ENOMEM when < 4.3) */

static PyObject* DBAgainError;          /* EAGAIN */

static PyObject* DBBusyError;           /* EBUSY  */

static PyObject* DBFileExistsError;     /* EEXIST */

static PyObject* DBNoSuchFileError;     /* ENOENT */

static PyObject* DBPermissionsError;    /* EPERM  */

#if (DBVER >= 42)

static PyObject* DBRepHandleDeadError;  /* DB_REP_HANDLE_DEAD */

#endif

static PyObject* DBRepUnavailError;     /* DB_REP_UNAVAIL */

#if (DBVER < 43)

#define	DB_BUFFER_SMALL		ENOMEM

#endif

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

/* Structure definitions */

#if PYTHON_API_VERSION < 1010

#error "Python 2.1 or later required"

#endif

/* Defaults for moduleFlags in DBEnvObject and DBObject. */

#define DEFAULT_GET_RETURNS_NONE                1

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

/* See comment in Python 2.6 "object.h" */

#ifndef staticforward

#define staticforward static

#endif

#ifndef statichere

#define statichere static

#endif

staticforward PyTypeObject DB_Type, DBCursor_Type, DBEnv_Type, DBTxn_Type,

              DBLock_Type;

#if (DBVER >= 43)

staticforward PyTypeObject DBSequence_Type;

#endif

#ifndef Py_TYPE

/* for compatibility with Python 2.5 and earlier */

#define Py_TYPE(ob)              (((PyObject*)(ob))->ob_type)

#endif

#define DBObject_Check(v)           (Py_TYPE(v) == &DB_Type)

#define DBCursorObject_Check(v)     (Py_TYPE(v) == &DBCursor_Type)

#define DBEnvObject_Check(v)        (Py_TYPE(v) == &DBEnv_Type)

#define DBTxnObject_Check(v)        (Py_TYPE(v) == &DBTxn_Type)

#define DBLockObject_Check(v)       (Py_TYPE(v) == &DBLock_Type)

#if (DBVER >= 43)

#define DBSequenceObject_Check(v)   (Py_TYPE(v) == &DBSequence_Type)

#endif

#if (DBVER < 46)

  #define _DBC_close(dbc)           dbc->c_close(dbc)

  #define _DBC_count(dbc,a,b)       dbc->c_count(dbc,a,b)

  #define _DBC_del(dbc,a)           dbc->c_del(dbc,a)

  #define _DBC_dup(dbc,a,b)         dbc->c_dup(dbc,a,b)

  #define _DBC_get(dbc,a,b,c)       dbc->c_get(dbc,a,b,c)

  #define _DBC_pget(dbc,a,b,c,d)    dbc->c_pget(dbc,a,b,c,d)

  #define _DBC_put(dbc,a,b,c)       dbc->c_put(dbc,a,b,c)

#else

  #define _DBC_close(dbc)           dbc->close(dbc)

  #define _DBC_count(dbc,a,b)       dbc->count(dbc,a,b)

  #define _DBC_del(dbc,a)           dbc->del(dbc,a)

  #define _DBC_dup(dbc,a,b)         dbc->dup(dbc,a,b)

  #define _DBC_get(dbc,a,b,c)       dbc->get(dbc,a,b,c)

  #define _DBC_pget(dbc,a,b,c,d)    dbc->pget(dbc,a,b,c,d)

  #define _DBC_put(dbc,a,b,c)       dbc->put(dbc,a,b,c)

#endif

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

/* Utility macros and functions */

#define INSERT_IN_DOUBLE_LINKED_LIST(backlink,object)                   \

    {                                                                   \

        object->sibling_next=backlink;                                  \

        object->sibling_prev_p=&(backlink);                             \

        backlink=object;                                                \

        if (object->sibling_next) {                                     \

          object->sibling_next->sibling_prev_p=&(object->sibling_next); \

        }                                                               \

    }

#define EXTRACT_FROM_DOUBLE_LINKED_LIST(object)                          \

    {                                                                    \

        if (object->sibling_next) {                                      \

            object->sibling_next->sibling_prev_p=object->sibling_prev_p; \

        }                                                                \

        *(object->sibling_prev_p)=object->sibling_next;                  \

    }

#define EXTRACT_FROM_DOUBLE_LINKED_LIST_MAYBE_NULL(object)               \

    {                                                                    \

        if (object->sibling_next) {                                      \

            object->sibling_next->sibling_prev_p=object->sibling_prev_p; \

        }                                                                \

        if (object->sibling_prev_p) {                                    \

            *(object->sibling_prev_p)=object->sibling_next;              \

        }                                                                \

    }

#define INSERT_IN_DOUBLE_LINKED_LIST_TXN(backlink,object)  \

    {                                                      \

        object->sibling_next_txn=backlink;                 \

        object->sibling_prev_p_txn=&(backlink);            \

        backlink=object;                                   \

        if (object->sibling_next_txn) {                    \

            object->sibling_next_txn->sibling_prev_p_txn=  \

                &(object->sibling_next_txn);               \

        }                                                  \

    }

#define EXTRACT_FROM_DOUBLE_LINKED_LIST_TXN(object)             \

    {                                                           \

        if (object->sibling_next_txn) {                         \

            object->sibling_next_txn->sibling_prev_p_txn=       \

                object->sibling_prev_p_txn;                     \

        }                                                       \

        *(object->sibling_prev_p_txn)=object->sibling_next_txn; \

    }

#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"); \

        if (errTuple) { \

            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)

#if (DBVER >= 43)

#define CHECK_SEQUENCE_NOT_CLOSED(curs) \

        _CHECK_OBJECT_NOT_CLOSED(curs->sequence, DBError, DBSequence)

#endif

#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)

{

    DBTYPE type;

    int err;

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

    if (makeDBError(err)) {

        return -1;

    }

    return type;

}

/* 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,

#if (PY_VERSION_HEX < 0x03000000)

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

#else

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

#endif

        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 (PyBytes_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,

#if (PY_VERSION_HEX < 0x03000000)

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

#else

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

#endif

            return 0;

        }

        /*

         * NOTE(gps): I don't like doing a data copy here, it seems

         * wasteful.  But without a clean way to tell FREE_DBT if it

         * should free key->data or not we have to.  Other places in

         * the code check for DB_THREAD and forceably set DBT_MALLOC

         * when we otherwise would leave flags 0 to indicate that.

         */

        key->data = malloc(PyBytes_GET_SIZE(keyobj));

        if (key->data == NULL) {

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

            return 0;

        }

        memcpy(key->data, PyBytes_AS_STRING(keyobj),

               PyBytes_GET_SIZE(keyobj));

        key->flags = DB_DBT_REALLOC;

        key->size = PyBytes_GET_SIZE(keyobj);

    }

    else if (NUMBER_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 = NUMBER_AsLong(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,

#if (PY_VERSION_HEX < 0x03000000)

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

#else

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

#endif

                     Py_TYPE(keyobj)->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;