Here is a bytes type. It's very minimal but it's a start.

2 files changed, 376 insertions, 0 deletions

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
new file mode 100644
index 0000000..8fc089b
--- /dev/null
+++ b/Objects/bytesobject.c
@@ -0,0 +1,373 @@
+/* Bytes object implementation */
+
+/* XXX TO DO: optimizations */
+
+#define PY_SSIZE_T_CLEAN
+#include "Python.h"
+
+/* Direct API functions */
+
+PyObject *
+PyBytes_FromStringAndSize(const char *sval, Py_ssize_t size)
+{
+    PyBytesObject *new;
+
+    if (size != 0) {
+	assert(sval != NULL);
+	assert(size > 0);
+    }
+
+    new = PyObject_New(PyBytesObject, &PyBytes_Type);
+    if (new == NULL)
+	return NULL;
+
+    if (size > 0) {
+	new->ob_sval = PyMem_Malloc(size);
+	if (new->ob_sval == NULL) {
+	    Py_DECREF(new);
+	    return NULL;
+	}
+	memcpy(new->ob_sval, sval, size);
+	new->ob_size = size;
+    }
+    
+    return (PyObject *)new;
+}
+
+Py_ssize_t
+PyBytes_Size(PyObject *self)
+{
+    assert(self != NULL);
+    assert(PyBytes_Check(self));
+
+    return ((PyBytesObject *)self)->ob_size;
+}
+
+char  *
+PyBytes_AsString(PyObject *self)
+{
+    assert(self != NULL);
+    assert(PyBytes_Check(self));
+
+    return ((PyBytesObject *)self)->ob_sval;
+}
+
+int
+PyBytes_Resize(PyObject *self, Py_ssize_t size)
+{
+    void *sval;
+
+    assert(self != NULL);
+    assert(PyBytes_Check(self));
+    assert(size >= 0);
+
+    sval = PyMem_Realloc(((PyBytesObject *)self)->ob_sval, size);
+    if (sval == NULL) {
+	PyErr_NoMemory();
+	return -1;
+    }
+
+    ((PyBytesObject *)self)->ob_sval = sval;
+    ((PyBytesObject *)self)->ob_size = size;
+
+    return 0;
+}
+
+/* Functions stuffed into the type object */
+
+static Py_ssize_t
+bytes_length(PyBytesObject *self)
+{
+    return self->ob_size;
+}
+
+static PyObject *
+bytes_getitem(PyBytesObject *self, Py_ssize_t i)
+{
+    if (i < 0)
+	i += self->ob_size;
+    if (i < 0 || i >= self->ob_size) {
+	PyErr_SetString(PyExc_IndexError, "bytes index out of range");
+	return NULL;
+    }
+    return PyInt_FromLong((unsigned char)(self->ob_sval[i]));
+}
+
+static long
+bytes_nohash(PyObject *self)
+{
+    PyErr_SetString(PyExc_TypeError, "bytes objects are unhashable");
+    return -1;
+}
+
+static int
+bytes_init(PyBytesObject *self, PyObject *args, PyObject *kwds)
+{
+    static char *kwlist[] = {"sequence", 0};
+    PyObject *arg = NULL;
+    PyObject *it; /* iter(arg) */
+    PyObject *(*iternext)(PyObject *);
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:bytes", kwlist, &arg))
+	return -1;
+
+    /* Verify list invariants established by PyType_GenericAlloc() */
+    if (self->ob_size != 0) {
+	assert(self->ob_sval != NULL);
+	assert(self->ob_size > 0);
+    }
+
+    /* Empty previous contents */
+    if (PyBytes_Resize((PyObject *)self, 0) < 0)
+	return -1;
+
+    /* Quick check if we're done */
+    if (arg == 0)
+	return 0;
+
+    /* XXX Optimize this if the arguments is a list, tuple, or bytes */
+
+    /* Get the iterator */
+    it = PyObject_GetIter(arg);
+    if (it == NULL)
+	return 0;
+    iternext = *it->ob_type->tp_iternext;
+
+    /* Run the iterator to exhaustion */
+    for (;;) {
+	PyObject *item;
+	Py_ssize_t value;
+
+	/* Get the next item */
+	item = iternext(it);
+	if (item == NULL) {
+	    if (PyErr_Occurred()) {
+		if (!PyErr_ExceptionMatches(PyExc_StopIteration))
+		    goto error;
+		PyErr_Clear();
+	    }
+	    break;
+	}
+
+	/* Interpret it as an int (__index__) */
+	value = PyNumber_Index(item);
+	if (value == -1 && PyErr_Occurred())
+	    goto error;
+
+	/* Range check */
+	if (value < 0 || value >= 256) {
+	    PyErr_SetString(PyExc_ValueError, "bytes must be in range(0, 256)");
+	    goto error;
+	}
+
+	/* Append the byte */
+	/* XXX Speed this up */
+	if (PyBytes_Resize((PyObject *)self, self->ob_size+1) < 0)
+	    goto error;
+	self->ob_sval[self->ob_size-1] = value;
+    }
+
+    /* Clean up and return success */
+    Py_DECREF(it);
+    return 0;
+
+ error:
+    /* Error handling when it != NULL */
+    Py_DECREF(it);
+    return -1;
+}
+
+static PyObject *
+bytes_repr(PyBytesObject *self)
+{
+    PyObject *list;
+    PyObject *str;
+    PyObject *result;
+    int err;
+    int i;
+
+    if (self->ob_size == 0)
+	return PyString_FromString("bytes()");
+
+    list = PyList_New(0);
+    if (list == NULL)
+	return NULL;
+
+    str = PyString_FromString("bytes([");
+    if (str == NULL)
+	goto error;
+
+    err = PyList_Append(list, str);
+    Py_DECREF(str);
+    if (err < 0)
+	goto error;
+
+    for (i = 0; i < self->ob_size; i++) {
+	char buffer[20];
+	sprintf(buffer, ", 0x%02x", (unsigned char) (self->ob_sval[i]));
+	str = PyString_FromString((i == 0) ? buffer+2 : buffer);
+	if (str == NULL)
+	    goto error;
+	err = PyList_Append(list, str);
+	Py_DECREF(str);
+	if (err < 0)
+	    goto error;
+    }
+
+    str = PyString_FromString("])");
+    if (str == NULL)
+	goto error;
+
+    err = PyList_Append(list, str);
+    Py_DECREF(str);
+    if (err < 0)
+	goto error;
+    
+    str = PyString_FromString("");
+    if (str == NULL)
+	goto error;
+
+    result = _PyString_Join(str, list);
+    Py_DECREF(str);
+    Py_DECREF(list);
+    return result;
+
+ error:
+    /* Error handling when list != NULL  */
+    Py_DECREF(list);
+    return NULL;
+}
+
+static PyObject *
+bytes_richcompare(PyBytesObject *self, PyBytesObject *other, int op)
+{
+    PyObject *res;
+    int minsize;
+    int cmp;
+
+    if (!PyBytes_Check(self) || !PyBytes_Check(other)) {
+	Py_INCREF(Py_NotImplemented);
+	return Py_NotImplemented;
+    }
+
+    if (self->ob_size != other->ob_size && (op == Py_EQ || op == Py_NE)) {
+	/* Shortcut: if the lengths differ, the objects differ */
+	cmp = (op == Py_NE);
+    }
+    else {
+	minsize = self->ob_size;
+	if (other->ob_size < minsize)
+	    minsize = other->ob_size;
+
+	cmp = memcmp(self->ob_sval, other->ob_sval, minsize);
+	/* In ISO C, memcmp() guarantees to use unsigned bytes! */
+
+	if (cmp == 0) {
+	    if (self->ob_size < other->ob_size)
+		cmp = -1;
+	    else if (self->ob_size > other->ob_size)
+		cmp = 1;
+	}
+
+	switch (op) {
+	case Py_LT: cmp = cmp <  0; break;
+	case Py_LE: cmp = cmp <= 0; break;
+	case Py_EQ: cmp = cmp == 0; break;
+	case Py_NE: cmp = cmp != 0; break;
+	case Py_GT: cmp = cmp >  0; break;
+	case Py_GE: cmp = cmp >= 0; break;
+	}
+    }
+
+    res = cmp ? Py_True : Py_False;
+    Py_INCREF(res);
+    return res;
+}
+
+static void
+bytes_dealloc(PyBytesObject *self)
+{
+    if (self->ob_sval != 0) {
+	PyMem_Free(self->ob_sval);
+    }
+    self->ob_type->tp_free((PyObject *)self);
+}
+
+static PySequenceMethods bytes_as_sequence = {
+    (lenfunc)bytes_length,		/*sq_length*/
+    (binaryfunc)0,			/*sq_concat*/
+    (ssizeargfunc)0,			/*sq_repeat*/
+    (ssizeargfunc)bytes_getitem,	/*sq_item*/
+    (ssizessizeargfunc)0,		/*sq_slice*/
+    0,					/*sq_ass_item*/
+    0,					/*sq_ass_slice*/
+    (objobjproc)0,			/*sq_contains*/
+};
+
+static PyMappingMethods bytes_as_mapping = {
+	(lenfunc)bytes_length,
+	(binaryfunc)0,
+	0,
+};
+
+static PyBufferProcs bytes_as_buffer = {
+/*
+	(readbufferproc)bytes_buffer_getreadbuf,
+	(writebufferproc)bytes_buffer_getwritebuf,
+	(segcountproc)bytes_buffer_getsegcount,
+	(charbufferproc)bytes_buffer_getcharbuf,
+*/
+};
+
+static PyMethodDef
+bytes_methods[] = {
+	{NULL,     NULL}
+};
+
+PyDoc_STRVAR(bytes_doc,
+"bytes([iterable]) -> new array of bytes.\n\
+\n\
+If an argument is given it must be an iterable yielding ints in range(256).");
+
+PyTypeObject PyBytes_Type = {
+    PyObject_HEAD_INIT(&PyType_Type)
+    0,
+    "bytes",
+    sizeof(PyBytesObject),
+    0,
+    (destructor)bytes_dealloc,		/* tp_dealloc */
+    0,			 		/* tp_print */
+    0,					/* tp_getattr */
+    0,					/* tp_setattr */
+    0,					/* tp_compare */
+    (reprfunc)bytes_repr,		/* tp_repr */
+    0,					/* tp_as_number */
+    &bytes_as_sequence,			/* tp_as_sequence */
+    &bytes_as_mapping,			/* tp_as_mapping */
+    bytes_nohash, 			/* tp_hash */
+    0,					/* tp_call */
+    0,					/* tp_str */
+    PyObject_GenericGetAttr,		/* tp_getattro */
+    0,					/* tp_setattro */
+    &bytes_as_buffer,			/* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES, /* tp_flags */ /* bytes is 'final' or 'sealed' */
+    bytes_doc,				/* tp_doc */
+    0,					/* tp_traverse */
+    0,					/* tp_clear */
+    (richcmpfunc)bytes_richcompare,	/* tp_richcompare */
+    0,					/* tp_weaklistoffset */
+    0,					/* tp_iter */
+    0,					/* tp_iternext */
+    bytes_methods,			/* tp_methods */
+    0,					/* tp_members */
+    0,					/* tp_getset */
+    0,					/* tp_base */
+    0,					/* tp_dict */
+    0,					/* tp_descr_get */
+    0,					/* tp_descr_set */
+    0,					/* tp_dictoffset */
+    (initproc)bytes_init,		/* tp_init */
+    PyType_GenericAlloc,		/* tp_alloc */
+    PyType_GenericNew,			/* tp_new */
+    PyObject_Del,	                /* tp_free */
+};
diff --git a/Objects/object.c b/Objects/object.c
index a75c14e..9a451d2 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1881,6 +1881,9 @@ _Py_ReadyTypes(void)
 	if (PyType_Ready(&PyBool_Type) < 0)
 		Py_FatalError("Can't initialize 'bool'");
 
+	if (PyType_Ready(&PyBytes_Type) < 0)
+		Py_FatalError("Can't initialize 'bytes'");
+
 	if (PyType_Ready(&PyString_Type) < 0)
 		Py_FatalError("Can't initialize 'str'");