bouquin-sqlcipher4/src/blob.c

644 lines
17 KiB
C

#include "blob.h"
#include "util.h"
int pysqlite_blob_init(pysqlite_Blob *self, pysqlite_Connection* connection,
sqlite3_blob *blob)
{
Py_INCREF(connection);
self->connection = connection;
self->offset = 0;
self->blob = blob;
self->in_weakreflist = NULL;
Py_BEGIN_ALLOW_THREADS
self->length = sqlite3_blob_bytes(self->blob);
Py_END_ALLOW_THREADS
if (!pysqlite_check_thread(self->connection)) {
return -1;
}
return 0;
}
static void remove_blob_from_connection_blob_list(pysqlite_Blob *self)
{
Py_ssize_t i;
PyObject *item;
for (i = 0; i < PyList_GET_SIZE(self->connection->blobs); i++) {
item = PyList_GET_ITEM(self->connection->blobs, i);
if (PyWeakref_GetObject(item) == (PyObject *)self) {
PyList_SetSlice(self->connection->blobs, i, i+1, NULL);
break;
}
}
}
static void _close_blob_inner(pysqlite_Blob* self)
{
sqlite3_blob *blob;
/* close the blob */
blob = self->blob;
self->blob = NULL;
if (blob) {
Py_BEGIN_ALLOW_THREADS
sqlite3_blob_close(blob);
Py_END_ALLOW_THREADS
}
/* remove from connection weaklist */
remove_blob_from_connection_blob_list(self);
if (self->in_weakreflist != NULL) {
PyObject_ClearWeakRefs((PyObject*)self);
}
}
static void pysqlite_blob_dealloc(pysqlite_Blob* self)
{
_close_blob_inner(self);
Py_XDECREF(self->connection);
Py_TYPE(self)->tp_free((PyObject*)self);
}
/*
* Checks if a blob object is usable (i. e. not closed).
*
* 0 => error; 1 => ok
*/
int pysqlite_check_blob(pysqlite_Blob *blob)
{
if (!blob->blob) {
PyErr_SetString(pysqlite_ProgrammingError,
"Cannot operate on a closed blob.");
return 0;
} else if (!pysqlite_check_connection(blob->connection) ||
!pysqlite_check_thread(blob->connection)) {
return 0;
} else {
return 1;
}
}
PyObject* pysqlite_blob_close(pysqlite_Blob *self)
{
if (!pysqlite_check_blob(self)) {
return NULL;
}
_close_blob_inner(self);
Py_RETURN_NONE;
};
static Py_ssize_t pysqlite_blob_length(pysqlite_Blob *self)
{
if (!pysqlite_check_blob(self)) {
return -1;
}
return self->length;
};
static PyObject* inner_read(pysqlite_Blob *self, int read_length, int offset)
{
PyObject *buffer;
char *raw_buffer;
int rc;
buffer = PyBytes_FromStringAndSize(NULL, read_length);
if (!buffer) {
return NULL;
}
raw_buffer = PyBytes_AS_STRING(buffer);
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_blob_read(self->blob, raw_buffer, read_length, self->offset);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
Py_DECREF(buffer);
/* For some reason after modifying blob the
error is not set on the connection db. */
if (rc == SQLITE_ABORT) {
PyErr_SetString(pysqlite_OperationalError,
"Cannot operate on modified blob");
} else {
_pysqlite_seterror(self->connection->db, NULL);
}
return NULL;
}
return buffer;
}
PyObject* pysqlite_blob_read(pysqlite_Blob *self, PyObject *args)
{
int read_length = -1;
PyObject *buffer;
if (!PyArg_ParseTuple(args, "|i", &read_length)) {
return NULL;
}
if (!pysqlite_check_blob(self)) {
return NULL;
}
if (read_length < 0) {
/* same as file read. */
read_length = self->length;
}
/* making sure we don't read more then blob size */
if (read_length > self->length - self->offset) {
read_length = self->length - self->offset;
}
buffer = inner_read(self, read_length, self->offset);
if (buffer != NULL) {
/* update offset on sucess. */
self->offset += read_length;
}
return buffer;
};
static int write_inner(pysqlite_Blob *self, const void *buf, Py_ssize_t len, int offset)
{
int rc;
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_blob_write(self->blob, buf, len, offset);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK) {
/* For some reason after modifying blob the
error is not set on the connection db. */
if (rc == SQLITE_ABORT) {
PyErr_SetString(pysqlite_OperationalError,
"Cannot operate on modified blob");
} else {
_pysqlite_seterror(self->connection->db, NULL);
}
return -1;
}
return 0;
}
PyObject* pysqlite_blob_write(pysqlite_Blob *self, PyObject *data)
{
Py_buffer data_buffer;
int rc;
if (PyObject_GetBuffer(data, &data_buffer, PyBUF_SIMPLE) < 0) {
return NULL;
}
if (data_buffer.len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"data longer than INT_MAX bytes");
PyBuffer_Release(&data_buffer);
return NULL;
}
if (!pysqlite_check_blob(self)) {
PyBuffer_Release(&data_buffer);
return NULL;
}
/* TODO: throw better error on data bigger then blob. */
rc = write_inner(self, data_buffer.buf, data_buffer.len, self->offset);
if (rc == 0) {
self->offset += (int)data_buffer.len;
PyBuffer_Release(&data_buffer);
Py_RETURN_NONE;
} else {
PyBuffer_Release(&data_buffer);
return NULL;
}
}
PyObject* pysqlite_blob_seek(pysqlite_Blob *self, PyObject *args)
{
int offset, from_what = 0;
if (!PyArg_ParseTuple(args, "i|i", &offset, &from_what)) {
return NULL;
}
if (!pysqlite_check_blob(self)) {
return NULL;
}
switch (from_what) {
case 0: // relative to blob begin
break;
case 1: // relative to current position
if (offset > INT_MAX - self->offset) {
goto overflow;
}
offset = self->offset + offset;
break;
case 2: // relative to blob end
if (offset > INT_MAX - self->length) {
goto overflow;
}
offset = self->length + offset;
break;
default:
return PyErr_Format(PyExc_ValueError,
"from_what should be 0, 1 or 2");
}
if (offset < 0 || offset > self->length) {
return PyErr_Format(PyExc_ValueError, "offset out of blob range");
}
self->offset = offset;
Py_RETURN_NONE;
overflow:
return PyErr_Format(PyExc_OverflowError, "seek offset result in overflow");
}
PyObject* pysqlite_blob_tell(pysqlite_Blob *self)
{
if (!pysqlite_check_blob(self)) {
return NULL;
}
return PyLong_FromLong(self->offset);
}
PyObject* pysqlite_blob_enter(pysqlite_Blob *self)
{
if (!pysqlite_check_blob(self)) {
return NULL;
}
Py_INCREF(self);
return (PyObject *)self;
}
PyObject* pysqlite_blob_exit(pysqlite_Blob *self, PyObject *args)
{
PyObject *res;
if (!pysqlite_check_blob(self)) {
return NULL;
}
res = pysqlite_blob_close(self);
if (!res) {
return NULL;
}
Py_XDECREF(res);
Py_RETURN_FALSE;
}
static PyObject* pysqlite_blob_concat(pysqlite_Blob *self, PyObject *args)
{
if (pysqlite_check_blob(self)) {
PyErr_SetString(PyExc_SystemError,
"Blob don't support concatenation");
}
return NULL;
}
static PyObject* pysqlite_blob_repeat(pysqlite_Blob *self, PyObject *args)
{
if (pysqlite_check_blob(self)) {
PyErr_SetString(PyExc_SystemError,
"Blob don't support repeat operation");
}
return NULL;
}
static int pysqlite_blob_contains(pysqlite_Blob *self, PyObject *args)
{
if (pysqlite_check_blob(self)) {
PyErr_SetString(PyExc_SystemError,
"Blob don't support cotains operation");
}
return -1;
}
static PyObject* pysqlite_blob_item(pysqlite_Blob *self, Py_ssize_t i)
{
if (!pysqlite_check_blob(self)) {
return NULL;
}
if (i < 0 || i >= self->length) {
PyErr_SetString(PyExc_IndexError, "Blob index out of range");
return NULL;
}
return inner_read(self, 1, i);
}
static int pysqlite_blob_ass_item(pysqlite_Blob *self, Py_ssize_t i, PyObject *v)
{
const char *buf;
if (!pysqlite_check_blob(self)) {
return -1;
}
if (i < 0 || i >= self->length) {
PyErr_SetString(PyExc_IndexError, "Blob index out of range");
return -1;
}
if (v == NULL) {
PyErr_SetString(PyExc_TypeError,
"Blob object doesn't support item deletion");
return -1;
}
if (! (PyBytes_Check(v) && PyBytes_Size(v)==1) ) {
PyErr_SetString(PyExc_IndexError,
"Blob assignment must be length-1 bytes()");
return -1;
}
buf = PyBytes_AsString(v);
return write_inner(self, buf, 1, i);
}
static PyObject * pysqlite_blob_subscript(pysqlite_Blob *self, PyObject *item)
{
if (!pysqlite_check_blob(self)) {
return NULL;
}
if (PyIndex_Check(item)) {
Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
if (i == -1 && PyErr_Occurred())
return NULL;
if (i < 0)
i += self->length;
if (i < 0 || i >= self->length) {
PyErr_SetString(PyExc_IndexError,
"Blob index out of range");
return NULL;
}
// TODO: I am not sure...
return inner_read(self, 1, i);
}
else if (PySlice_Check(item)) {
Py_ssize_t start, stop, step, slicelen;
if (PySlice_GetIndicesEx(item, self->length,
&start, &stop, &step, &slicelen) < 0) {
return NULL;
}
if (slicelen <= 0)
return PyBytes_FromStringAndSize("", 0);
else if (step == 1)
return inner_read(self, slicelen, start);
else {
char *result_buf = (char *)PyMem_Malloc(slicelen);
char *data_buff = NULL;
Py_ssize_t cur, i;
PyObject *result;
int rc;
if (result_buf == NULL)
return PyErr_NoMemory();
data_buff = (char *)PyMem_Malloc(stop - start);
if (data_buff == NULL) {
PyMem_Free(result_buf);
return PyErr_NoMemory();
}
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_blob_read(self->blob, data_buff, stop - start, start);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
/* For some reason after modifying blob the
error is not set on the connection db. */
if (rc == SQLITE_ABORT) {
PyErr_SetString(pysqlite_OperationalError,
"Cannot operate on modified blob");
} else {
_pysqlite_seterror(self->connection->db, NULL);
}
PyMem_Free(result_buf);
PyMem_Free(data_buff);
return NULL;
}
for (cur = 0, i = 0; i < slicelen;
cur += step, i++) {
result_buf[i] = data_buff[cur];
}
result = PyBytes_FromStringAndSize(result_buf,
slicelen);
PyMem_Free(result_buf);
PyMem_Free(data_buff);
return result;
}
}
else {
PyErr_SetString(PyExc_TypeError,
"Blob indices must be integers");
return NULL;
}
}
static int pysqlite_blob_ass_subscript(pysqlite_Blob *self, PyObject *item, PyObject *value)
{
int rc;
if (!pysqlite_check_blob(self)) {
return -1;
}
if (PyIndex_Check(item)) {
Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
const char *buf;
if (i == -1 && PyErr_Occurred())
return -1;
if (i < 0)
i += self->length;
if (i < 0 || i >= self->length) {
PyErr_SetString(PyExc_IndexError,
"Blob index out of range");
return -1;
}
if (value == NULL) {
PyErr_SetString(PyExc_TypeError,
"Blob doesn't support item deletion");
return -1;
}
if (! (PyBytes_Check(value) && PyBytes_Size(value)==1) ) {
PyErr_SetString(PyExc_IndexError,
"Blob assignment must be length-1 bytes()");
return -1;
}
buf = PyBytes_AsString(value);
return write_inner(self, buf, 1, i);
}
else if (PySlice_Check(item)) {
Py_ssize_t start, stop, step, slicelen;
Py_buffer vbuf;
if (PySlice_GetIndicesEx(item,
self->length, &start, &stop,
&step, &slicelen) < 0) {
return -1;
}
if (value == NULL) {
PyErr_SetString(PyExc_TypeError,
"Blob object doesn't support slice deletion");
return -1;
}
if (PyObject_GetBuffer(value, &vbuf, PyBUF_SIMPLE) < 0)
return -1;
if (vbuf.len != slicelen) {
PyErr_SetString(PyExc_IndexError,
"Blob slice assignment is wrong size");
PyBuffer_Release(&vbuf);
return -1;
}
if (slicelen == 0) {
}
else if (step == 1) {
rc = write_inner(self, vbuf.buf, slicelen, start);
}
else {
Py_ssize_t cur, i;
char *data_buff;
data_buff = (char *)PyMem_Malloc(stop - start);
if (data_buff == NULL) {
PyErr_NoMemory();
return -1;
}
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_blob_read(self->blob, data_buff, stop - start, start);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
/* For some reason after modifying blob the
error is not set on the connection db. */
if (rc == SQLITE_ABORT) {
PyErr_SetString(pysqlite_OperationalError,
"Cannot operate on modified blob");
} else {
_pysqlite_seterror(self->connection->db, NULL);
}
PyMem_Free(data_buff);
rc = -1;
}
for (cur = 0, i = 0;
i < slicelen;
cur += step, i++)
{
data_buff[cur] = ((char *)vbuf.buf)[i];
}
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_blob_write(self->blob, data_buff, stop - start, start);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
/* For some reason after modifying blob the
error is not set on the connection db. */
if (rc == SQLITE_ABORT) {
PyErr_SetString(pysqlite_OperationalError,
"Cannot operate on modified blob");
} else {
_pysqlite_seterror(self->connection->db, NULL);
}
PyMem_Free(data_buff);
rc = -1;
}
rc = 0;
}
PyBuffer_Release(&vbuf);
return rc;
}
else {
PyErr_SetString(PyExc_TypeError,
"mmap indices must be integer");
return -1;
}
}
static PyMethodDef blob_methods[] = {
{"read", (PyCFunction)pysqlite_blob_read, METH_VARARGS,
PyDoc_STR("read data from blob")},
{"write", (PyCFunction)pysqlite_blob_write, METH_O,
PyDoc_STR("write data to blob")},
{"close", (PyCFunction)pysqlite_blob_close, METH_NOARGS,
PyDoc_STR("close blob")},
{"seek", (PyCFunction)pysqlite_blob_seek, METH_VARARGS,
PyDoc_STR("change blob current offset")},
{"tell", (PyCFunction)pysqlite_blob_tell, METH_NOARGS,
PyDoc_STR("return blob current offset")},
{"__enter__", (PyCFunction)pysqlite_blob_enter, METH_NOARGS,
PyDoc_STR("blob context manager enter")},
{"__exit__", (PyCFunction)pysqlite_blob_exit, METH_VARARGS,
PyDoc_STR("blob context manager exit")},
{NULL, NULL}
};
static PySequenceMethods blob_sequence_methods = {
.sq_length = (lenfunc)pysqlite_blob_length,
.sq_concat = (binaryfunc)pysqlite_blob_concat,
.sq_repeat = (ssizeargfunc)pysqlite_blob_repeat,
.sq_item = (ssizeargfunc)pysqlite_blob_item,
.sq_ass_item = (ssizeobjargproc)pysqlite_blob_ass_item,
.sq_contains = (objobjproc)pysqlite_blob_contains,
};
static PyMappingMethods blob_mapping_methods = {
(lenfunc)pysqlite_blob_length,
(binaryfunc)pysqlite_blob_subscript,
(objobjargproc)pysqlite_blob_ass_subscript,
};
PyTypeObject pysqlite_BlobType = {
PyVarObject_HEAD_INIT(NULL, 0)
MODULE_NAME ".Blob",
.tp_basicsize = sizeof(pysqlite_Blob),
.tp_dealloc = (destructor)pysqlite_blob_dealloc,
.tp_as_sequence = &blob_sequence_methods,
.tp_as_mapping = &blob_mapping_methods,
.tp_flags = Py_TPFLAGS_DEFAULT,
.tp_weaklistoffset = offsetof(pysqlite_Blob, in_weakreflist),
.tp_methods = blob_methods,
};
extern int pysqlite_blob_setup_types(void)
{
pysqlite_BlobType.tp_new = PyType_GenericNew;
return PyType_Ready(&pysqlite_BlobType);
}