source: vbox/trunk/src/libs/xpcom18a4/python/src/PyIInputStream.cpp

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Python XPCOM language bindings.
 *
 * The Initial Developer of the Original Code is
 * ActiveState Tool Corp.
 * Portions created by the Initial Developer are Copyright (C) 2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Mark Hammond <mhammond@skippinet.com.au> (original author)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

//
// This code is part of the XPCOM extensions for Python.
//
// Written September 2000 by Mark Hammond.
//
// Based heavily on the Python COM support, which is
// (c) Mark Hammond and Greg Stein.
//
// (c) 2000, ActiveState corp.

#include "PyXPCOM_std.h"
#include "nsIInputStream.h"

// Prevents us needing to use an nsIScriptableInputStream
// (and even that can't read binary data!!!)

static nsIInputStream *GetI(PyObject *self) {
        nsIID iid = NS_GET_IID(nsIInputStream);

        if (!Py_nsISupports::Check(self, iid)) {
                PyErr_SetString(PyExc_TypeError, "This object is not the correct interface");
                return NULL;
        }
        return (nsIInputStream *)Py_nsISupports::GetI(self);
}

static PyObject *DoPyRead_Buffer(nsIInputStream *pI, PyObject *obBuffer, PRUint32 n)
{
        PRUint32 nread;
        void *buf;
#ifndef VBOX /* unsafe cast on 64-bit hosts. */
        PRUint32 buf_len;
        if (PyObject_AsWriteBuffer(obBuffer, &buf, (Py_ssize_t *)&buf_len) != 0) {
#else   /* VBOX */
# if PY_VERSION_HEX >= 0x02050000 || defined(PY_SSIZE_T_MIN)
        Py_ssize_t buf_len;
# else
        int buf_len;
# endif /* VBOX */
        if (PyObject_AsWriteBuffer(obBuffer, &buf, &buf_len) != 0) {
#endif
                PyErr_Clear();
                PyErr_SetString(PyExc_TypeError, "The buffer object does not have a write buffer!");
                return NULL;
        }
        if (n==(PRUint32)-1) {
                n = buf_len;
        } else {
                if (n > buf_len) {
                        NS_WARNING("Warning: PyIInputStream::read() was passed an integer size greater than the size of the passed buffer!  Buffer size used.\n");
                        n = buf_len;
                }
        }
        nsresult r;
        Py_BEGIN_ALLOW_THREADS;
        r = pI->Read((char *)buf, n, &nread);
        Py_END_ALLOW_THREADS;
        if ( NS_FAILED(r) )
                return PyXPCOM_BuildPyException(r);
        return PyInt_FromLong(nread);
}

static PyObject *DoPyRead_Size(nsIInputStream *pI, PRUint32 n)
{
        if (n==(PRUint32)-1) {
                nsresult r;
                Py_BEGIN_ALLOW_THREADS;
                r = pI->Available(&n);
                Py_END_ALLOW_THREADS;
                if (NS_FAILED(r))
                        return PyXPCOM_BuildPyException(r);
        }
        if (n==0) { // mozilla will assert if we alloc zero bytes.
#if PY_MAJOR_VERSION <= 2
                return PyBuffer_New(0);
#else
                return PyBytes_FromString("");
#endif
        }
        char *buf = (char *)nsMemory::Alloc(n);
        if (buf==NULL) {
                PyErr_NoMemory();
                return NULL;
        }
        nsresult r;
        PRUint32 nread;
        Py_BEGIN_ALLOW_THREADS;
        r = pI->Read(buf, n, &nread);
        Py_END_ALLOW_THREADS;
        PyObject *rc = NULL;
        if ( NS_SUCCEEDED(r) ) {
#if PY_MAJOR_VERSION <= 2
                rc = PyBuffer_New(nread);
                if (rc != NULL) {
                        void *ob_buf;
#ifndef VBOX /* unsafe cast on 64-bit hosts. */
                        PRUint32 buf_len;
                        if (PyObject_AsWriteBuffer(rc, &ob_buf, (Py_ssize_t *)&buf_len) != 0) {
#else   /* VBOX */
# if PY_VERSION_HEX >= 0x02050000 || defined(PY_SSIZE_T_MIN)
                        Py_ssize_t buf_len;
# else
                        int buf_len;
# endif /* VBOX */
                        if (PyObject_AsWriteBuffer(rc, &ob_buf, &buf_len) != 0) {
#endif
                                // should never fail - we just created it!
                                return NULL;
                        }
                        if (buf_len != nread) {
                                PyErr_SetString(PyExc_RuntimeError, "New buffer isnt the size we create it!");
                                return NULL;
                        }
                        memcpy(ob_buf, buf, nread);
                }
#else
        rc = PyBytes_FromStringAndSize(buf, nread);
#endif
        } else
                PyXPCOM_BuildPyException(r);
        nsMemory::Free(buf);
        return rc;
}

static PyObject *PyRead(PyObject *self, PyObject *args)
{
        PyObject *obBuffer = NULL;
        PRUint32 n = (PRUint32)-1;

        nsIInputStream *pI = GetI(self);
        if (pI==NULL)
                return NULL;
        if (PyArg_ParseTuple(args, "|i", (int *)&n))
                // This worked - no args, or just an int.
                return DoPyRead_Size(pI, n);
        // try our other supported arg format.
        PyErr_Clear();
        if (!PyArg_ParseTuple(args, "O|i", &obBuffer, (int *)&n)) {
                PyErr_Clear();
                PyErr_SetString(PyExc_TypeError, "'read()' must be called as (buffer_ob, int_size=-1) or (int_size=-1)");
                return NULL;
        }
        return DoPyRead_Buffer(pI, obBuffer, n);
}


struct PyMethodDef
PyMethods_IInputStream[] =
{
        { "read", PyRead, 1},
        // The rest are handled as normal
        {NULL}
};