Modules/bsddbmodule.c

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

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/* Berkeley DB interface.
   Author: Michael McLay
   Hacked: Guido van Rossum
   Btree and Recno additions plus sequence methods: David Ely

   XXX To do:
   - provide interface to the B-tree and record libraries too
   - provide a way to access the various hash functions
   - support more open flags
 */

#include "Python.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <db.h>
/* 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 */
} bsddbobject;

staticforward PyTypeObject Bsddbtype;

#define is_bsddbobject(v) ((v)->ob_type == &Bsddbtype)

static PyObject *BsddbError;

static PyObject *
newdbhashobject(file, flags, mode,
		bsize, ffactor, nelem, cachesize, hash, lorder)
    char *file;
    int flags;
    int mode;
    int bsize;
    int ffactor;
    int nelem;
    int cachesize;
    int hash; /* XXX ignored */
    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
    if ((dp->di_bsddb = dbopen(file, flags, mode, DB_HASH, &info)) == NULL) {
	PyErr_SetFromErrno(BsddbError);
	Py_DECREF(dp);
	return NULL;
    }

    dp->di_size = -1;

    return (PyObject *)dp;
}

static PyObject *
newdbbtobject(file, flags, mode,
		btflags, cachesize, maxkeypage, minkeypage, psize, lorder)
    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
    if ((dp->di_bsddb = dbopen(file, flags, mode, DB_BTREE, &info)) == NULL) {
	PyErr_SetFromErrno(BsddbError);
	Py_DECREF(dp);
	return NULL;
    }

    dp->di_size = -1;

    return (PyObject *)dp;
}

static PyObject *
newdbrnobject(file, flags, mode,
		rnflags, cachesize, psize, lorder, reclen, bval, bfname)
    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;

    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
    if ((dp->di_bsddb = dbopen(file, flags, mode, DB_RECNO, &info)) == NULL) {
	PyErr_SetFromErrno(BsddbError);
	Py_DECREF(dp);
	return NULL;
    }

    dp->di_size = -1;

    return (PyObject *)dp;
}


static void
bsddb_dealloc(dp)
    bsddbobject *dp;
{
    if (dp->di_bsddb != NULL) {
	if ((dp->di_bsddb->close)(dp->di_bsddb) != 0)
	    fprintf(stderr,
		    "Python bsddb: close errno %d in dealloc\n", errno);
    }
    PyMem_DEL(dp);
}

static int
bsddb_length(dp)
    bsddbobject *dp;
{
    if (dp->di_size < 0) {
	DBT krec, drec;
	int status;
	int size = 0;
	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++;
	if (status < 0) {
	    PyErr_SetFromErrno(BsddbError);
	    return -1;
	}
	dp->di_size = size;
    }
    return dp->di_size;
}

static PyObject *
bsddb_subscript(dp, key)
    bsddbobject *dp;
    PyObject *key;
{
    int status;
    DBT krec, drec;
    char *data;
    int size;

    if (!PyArg_Parse(key, "s#", &data, &size))
	return NULL;
    krec.data = data;
    krec.size = size;

    status = (dp->di_bsddb->get)(dp->di_bsddb, &krec, &drec, 0);
    if (status != 0) {
	if (status < 0)
	    PyErr_SetFromErrno(BsddbError);
	else
	    PyErr_SetObject(PyExc_KeyError, key);
	return NULL;
    }

    return PyString_FromStringAndSize((char *)drec.data, (int)drec.size);
}

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

    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;
    dp->di_size = -1;
    if (value == NULL) {
	status = (dp->di_bsddb->del)(dp->di_bsddb, &krec, 0);
    }
    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;
	status = (dp->di_bsddb->put)(dp->di_bsddb, &krec, &drec, 0);
    }
    if (status != 0) {
	if (status < 0)
	    PyErr_SetFromErrno(BsddbError);
	else
	    PyErr_SetObject(PyExc_KeyError, key);
	return -1;
    }
    return 0;
}

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

static PyObject *
bsddb_close(dp, args)
    bsddbobject *dp;
    PyObject *args;
{
    if (!PyArg_NoArgs(args))
	return NULL;
    if (dp->di_bsddb != NULL) {
	if ((dp->di_bsddb->close)(dp->di_bsddb) != 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(dp, args)
    bsddbobject *dp;
    PyObject *args;
{
    PyObject *list, *item;
    DBT krec, drec;
    int status;
    int err;

    if (!PyArg_NoArgs(args))
	return NULL;
    list = PyList_New(0);
    if (list == NULL)
	return NULL;
    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)) {
	item = PyString_FromStringAndSize((char *)krec.data, (int)krec.size);
	if (item == NULL) {
	    Py_DECREF(list);
	    return NULL;
	}
	err = PyList_Append(list, item);
	Py_DECREF(item);
	if (err != 0) {
	    Py_DECREF(list);
	    return NULL;
	}
    }
    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 for this... */
    return list;
}

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

    if (!PyArg_Parse(args, "s#", &data, &size))
	return NULL;
    krec.data = data;
    krec.size = size;

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

    return PyInt_FromLong(status == 0);
}

static PyObject *
bsddb_set_location(dp, key)
    bsddbobject *dp;
    PyObject *key;
{
    int status;
    DBT krec, drec;
    char *data;
    int size;

    if (!PyArg_Parse(key, "s#", &data, &size))
	return NULL;
    krec.data = data;
    krec.size = size;

    status = (dp->di_bsddb->seq)(dp->di_bsddb, &krec, &drec, R_CURSOR);
    if (status != 0) {
	if (status < 0)
	    PyErr_SetFromErrno(BsddbError);
	else
	    PyErr_SetObject(PyExc_KeyError, key);
	return NULL;
    }

    return Py_BuildValue("s#s#", krec.data, krec.size, drec.data, drec.size);
}

static PyObject *
bsddb_seq(dp, args, sequence_request)
    bsddbobject *dp;
    PyObject *args;
    int sequence_request;
{
    int status;
    DBT krec, drec;

    if (!PyArg_NoArgs(args))
	return NULL;

    krec.data = 0;
    krec.size = 0;

    status = (dp->di_bsddb->seq)(dp->di_bsddb, &krec, &drec, sequence_request);
    if (status != 0) {
	if (status < 0)
	    PyErr_SetFromErrno(BsddbError);
	else
	    PyErr_SetObject(PyExc_KeyError, args);
	return NULL;
    }

    return Py_BuildValue("s#s#", krec.data, krec.size, drec.data, drec.size);
}

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

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

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

static PyTypeObject Bsddbtype = {
    PyObject_HEAD_INIT(NULL)
    0,
    "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(self, args)
    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, "s|siiiiiii",
		 &file, &flag, &mode,
		 &bsize, &ffactor, &nelem, &cachesize, &hash, &lorder))
	  return NULL;
    if (flag != NULL) {
	/* XXX need a way 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(self, args)
    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, "s|siiiiiii",
		    &file, &flag, &mode,
		    &btflags, &cachesize, &maxkeypage, &minkeypage,
		    &psize, &lorder))
	  return NULL;
    if (flag != NULL) {
	/* XXX need a way 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(self, args)
    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, "s|siiiiiiss",
		    &file, &flag, &mode,
		    &rnflags, &cachesize, &psize, &lorder,
		    &reclen, &bval, &bfname))
	  return NULL;
    if (flag != NULL) {
	/* XXX need a way 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, bval[0], bfname);
}

static PyMethodDef bsddbmodule_methods[] = {
    {"hashopen",	(PyCFunction)bsdhashopen, 1},
    {"btopen",		(PyCFunction)bsdbtopen, 1},
    {"rnopen",		(PyCFunction)bsdrnopen, 1},
    {0,		0},
};

void
initbsddb() {
    PyObject *m, *d;

    Bsddbtype.ob_type = &PyType_Type;
    m = Py_InitModule("bsddb", bsddbmodule_methods);
    d = PyModule_GetDict(m);
    BsddbError = PyString_FromString("bsddb.error");
    if (BsddbError == NULL || PyDict_SetItemString(d, "error", BsddbError))
	Py_FatalError("can't define bsddb.error");
}