/* PyBytes (bytearray) implementation */

#define PY_SSIZE_T_CLEAN
#include "Python.h"
#include "structmember.h"
#include "bytes_methods.h"

static PyByteArrayObject *nullbytes = NULL;

void
PyByteArray_Fini(void)
{
    Py_CLEAR(nullbytes);
}

int
PyByteArray_Init(void)
{
    nullbytes = PyObject_New(PyByteArrayObject, &PyByteArray_Type);
    if (nullbytes == NULL)
        return 0;
    nullbytes->ob_bytes = NULL;
    Py_SIZE(nullbytes) = nullbytes->ob_alloc = 0;
    nullbytes->ob_exports = 0;
    return 1;
}

/* end nullbytes support */

/* Helpers */

static int
_getbytevalue(PyObject* arg, int *value)
{
    long face_value;

    if (PyBytes_CheckExact(arg)) {
        if (Py_SIZE(arg) != 1) {
            PyErr_SetString(PyExc_ValueError, "string must be of size 1");
            return 0;
        }
        *value = Py_CHARMASK(((PyBytesObject*)arg)->ob_sval[0]);
        return 1;
    }
    else if (PyInt_Check(arg) || PyLong_Check(arg)) {
        face_value = PyLong_AsLong(arg);
    }
    else {
        PyObject *index = PyNumber_Index(arg);
        if (index == NULL) {
            PyErr_Format(PyExc_TypeError,
                         "an integer or string of size 1 is required");
            return 0;
        }
        face_value = PyLong_AsLong(index);
        Py_DECREF(index);
    }

    if (face_value < 0 || face_value >= 256) {
        /* this includes the OverflowError in case the long is too large */
        PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
        return 0;
    }

    *value = face_value;
    return 1;
}

static Py_ssize_t
bytes_buffer_getreadbuf(PyByteArrayObject *self, Py_ssize_t index, const void **ptr)
{
    if ( index != 0 ) {
        PyErr_SetString(PyExc_SystemError,
                "accessing non-existent bytes segment");
        return -1;
    }
    *ptr = (void *)self->ob_bytes;
    return Py_SIZE(self);
}

static Py_ssize_t
bytes_buffer_getwritebuf(PyByteArrayObject *self, Py_ssize_t index, const void **ptr)
{
    if ( index != 0 ) {
        PyErr_SetString(PyExc_SystemError,
                "accessing non-existent bytes segment");
        return -1;
    }
    *ptr = (void *)self->ob_bytes;
    return Py_SIZE(self);
}

static Py_ssize_t
bytes_buffer_getsegcount(PyByteArrayObject *self, Py_ssize_t *lenp)
{
    if ( lenp )
        *lenp = Py_SIZE(self);
    return 1;
}

static Py_ssize_t
bytes_buffer_getcharbuf(PyByteArrayObject *self, Py_ssize_t index, const char **ptr)
{
    if ( index != 0 ) {
        PyErr_SetString(PyExc_SystemError,
                "accessing non-existent bytes segment");
        return -1;
    }
    *ptr = self->ob_bytes;
    return Py_SIZE(self);
}

static int
bytes_getbuffer(PyByteArrayObject *obj, Py_buffer *view, int flags)
{
        int ret;
        void *ptr;
        if (view == NULL) {
                obj->ob_exports++;
                return 0;
        }
        if (obj->ob_bytes == NULL)
                ptr = "";
        else
                ptr = obj->ob_bytes;
        ret = PyBuffer_FillInfo(view, (PyObject*)obj, ptr, Py_SIZE(obj), 0, flags);
        if (ret >= 0) {
                obj->ob_exports++;
        }
        return ret;
}

static void
bytes_releasebuffer(PyByteArrayObject *obj, Py_buffer *view)
{
        obj->ob_exports--;
}

static Py_ssize_t
_getbuffer(PyObject *obj, Py_buffer *view)
{
    PyBufferProcs *buffer = Py_TYPE(obj)->tp_as_buffer;

    if (buffer == NULL || buffer->bf_getbuffer == NULL)
    {
        PyErr_Format(PyExc_TypeError,
                     "Type %.100s doesn't support the buffer API",
                     Py_TYPE(obj)->tp_name);
        return -1;
    }

    if (buffer->bf_getbuffer(obj, view, PyBUF_SIMPLE) < 0)
            return -1;
    return view->len;
}

static int
_canresize(PyByteArrayObject *self)
{
    if (self->ob_exports > 0) {
        PyErr_SetString(PyExc_BufferError,
                "Existing exports of data: object cannot be re-sized");
        return 0;
    }
    return 1;
}

/* Direct API functions */

PyObject *
PyByteArray_FromObject(PyObject *input)
{
    return PyObject_CallFunctionObjArgs((PyObject *)&PyByteArray_Type,
                                        input, NULL);
}

PyObject *
PyByteArray_FromStringAndSize(const char *bytes, Py_ssize_t size)
{
    PyByteArrayObject *new;
    Py_ssize_t alloc;

    if (size < 0) {
        PyErr_SetString(PyExc_SystemError,
            "Negative size passed to PyByteArray_FromStringAndSize");
        return NULL;
    }

    new = PyObject_New(PyByteArrayObject, &PyByteArray_Type);
    if (new == NULL)
        return NULL;

    if (size == 0) {
        new->ob_bytes = NULL;
        alloc = 0;
    }
    else {
        alloc = size + 1;
        new->ob_bytes = PyMem_Malloc(alloc);
        if (new->ob_bytes == NULL) {
            Py_DECREF(new);
            return PyErr_NoMemory();
        }
        if (bytes != NULL)
            memcpy(new->ob_bytes, bytes, size);
        new->ob_bytes[size] = '\0';  /* Trailing null byte */
    }
    Py_SIZE(new) = size;
    new->ob_alloc = alloc;
    new->ob_exports = 0;

    return (PyObject *)new;
}

Py_ssize_t
PyByteArray_Size(PyObject *self)
{
    assert(self != NULL);
    assert(PyByteArray_Check(self));

    return PyByteArray_GET_SIZE(self);
}

char  *
PyByteArray_AsString(PyObject *self)
{
    assert(self != NULL);
    assert(PyByteArray_Check(self));

    return PyByteArray_AS_STRING(self);
}

int
PyByteArray_Resize(PyObject *self, Py_ssize_t size)
{
    void *sval;
    Py_ssize_t alloc = ((PyByteArrayObject *)self)->ob_alloc;

    assert(self != NULL);
    assert(PyByteArray_Check(self));
    assert(size >= 0);

    if (size == Py_SIZE(self)) {
        return 0;
    }
    if (!_canresize((PyByteArrayObject *)self)) {
        return -1;
    }

    if (size < alloc / 2) {
        /* Major downsize; resize down to exact size */
        alloc = size + 1;
    }
    else if (size < alloc) {
        /* Within allocated size; quick exit */
        Py_SIZE(self) = size;
        ((PyByteArrayObject *)self)->ob_bytes[size] = '\0'; /* Trailing null */
        return 0;
    }
    else if (size <= alloc * 1.125) {
        /* Moderate upsize; overallocate similar to list_resize() */
        alloc = size + (size >> 3) + (size < 9 ? 3 : 6);
    }
    else {
        /* Major upsize; resize up to exact size */
        alloc = size + 1;
    }

    sval = PyMem_Realloc(((PyByteArrayObject *)self)->ob_bytes, alloc);
    if (sval == NULL) {
        PyErr_NoMemory();
        return -1;
    }

    ((PyByteArrayObject *)self)->ob_bytes = sval;
    Py_SIZE(self) = size;
    ((PyByteArrayObject *)self)->ob_alloc = alloc;
    ((PyByteArrayObject *)self)->ob_bytes[size] = '\0'; /* Trailing null byte */

    return 0;
}

PyObject *
PyByteArray_Concat(PyObject *a, PyObject *b)
{
    Py_ssize_t size;
    Py_buffer va, vb;
    PyByteArrayObject *result = NULL;

    va.len = -1;
    vb.len = -1;
    if (_getbuffer(a, &va) < 0  ||
        _getbuffer(b, &vb) < 0) {
            PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
                         Py_TYPE(a)->tp_name, Py_TYPE(b)->tp_name);
            goto done;
    }

    size = va.len + vb.len;
    if (size < 0) {
            return PyErr_NoMemory();
            goto done;
    }

    result = (PyByteArrayObject *) PyByteArray_FromStringAndSize(NULL, size);
    if (result != NULL) {
        memcpy(result->ob_bytes, va.buf, va.len);
        memcpy(result->ob_bytes + va.len, vb.buf, vb.len);
    }

  done:
    if (va.len != -1)
        PyBuffer_Release(&va);
    if (vb.len != -1)
        PyBuffer_Release(&vb);
    return (PyObject *)result;
}

/* Functions stuffed into the type object */

static Py_ssize_t
bytes_length(PyByteArrayObject *self)
{
    return Py_SIZE(self);
}

static PyObject *
bytes_iconcat(PyByteArrayObject *self, PyObject *other)
{
    Py_ssize_t mysize;
    Py_ssize_t size;
    Py_buffer vo;

    if (_getbuffer(other, &vo) < 0) {
        PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
                     Py_TYPE(other)->tp_name, Py_TYPE(self)->tp_name);
        return NULL;
    }

    mysize = Py_SIZE(self);
    size = mysize + vo.len;
    if (size < 0) {
        PyBuffer_Release(&vo);
        return PyErr_NoMemory();
    }
    if (size < self->ob_alloc) {
        Py_SIZE(self) = size;
        self->ob_bytes[Py_SIZE(self)] = '\0'; /* Trailing null byte */
    }
    else if (PyByteArray_Resize((PyObject *)self, size) < 0) {
        PyBuffer_Release(&vo);
        return NULL;
    }
    memcpy(self->ob_bytes + mysize, vo.buf, vo.len);
    PyBuffer_Release(&vo);
    Py_INCREF(self);
    return (PyObject *)self;
}

static PyObject *
bytes_repeat(PyByteArrayObject *self, Py_ssize_t count)
{
    PyByteArrayObject *result;
    Py_ssize_t mysize;
    Py_ssize_t size;

    if (count < 0)
        count = 0;
    mysize = Py_SIZE(self);
    size = mysize * count;
    if (count != 0 && size / count != mysize)
        return PyErr_NoMemory();
    result = (PyByteArrayObject *)PyByteArray_FromStringAndSize(NULL, size);
    if (result != NULL && size != 0) {
        if (mysize == 1)
            memset(result->ob_bytes, self->ob_bytes[0], size);
        else {
            Py_ssize_t i;
            for (i = 0; i < count; i++)
                memcpy(result->ob_bytes + i*mysize, self->ob_bytes, mysize);
        }
    }
    return (PyObject *)result;
}

static PyObject *
bytes_irepeat(PyByteArrayObject *self, Py_ssize_t count)
{
    Py_ssize_t mysize;
    Py_ssize_t size;

    if (count < 0)
        count = 0;
    mysize = Py_SIZE(self);
    size = mysize * count;
    if (count != 0 && size / count != mysize)
        return PyErr_NoMemory();
    if (size < self->ob_alloc) {
        Py_SIZE(self) = size;
        self->ob_bytes[Py_SIZE(self)] = '\0'; /* Trailing null byte */
    }
    else if (PyByteArray_Resize((PyObject *)self, size) < 0)
        return NULL;

    if (mysize == 1)
        memset(self->ob_bytes, self->ob_bytes[0], size);
    else {
        Py_ssize_t i;
        for (i = 1; i < count; i++)
            memcpy(self->ob_bytes + i*mysize, self->ob_bytes, mysize);
    }

    Py_INCREF(self);
    return (PyObject *)self;
}

static PyObject *
bytes_getitem(PyByteArrayObject *self, Py_ssize_t i)
{
    if (i < 0)
        i += Py_SIZE(self);
    if (i < 0 || i >= Py_SIZE(self)) {
        PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
        return NULL;
    }
    return PyInt_FromLong((unsigned char)(self->ob_bytes[i]));
}

static PyObject *
bytes_subscript(PyByteArrayObject *self, PyObject *index)
{
    if (PyIndex_Check(index)) {
        Py_ssize_t i = PyNumber_AsSsize_t(index, PyExc_IndexError);

        if (i == -1 && PyErr_Occurred())
            return NULL;

        if (i < 0)
            i += PyByteArray_GET_SIZE(self);

        if (i < 0 || i >= Py_SIZE(self)) {
            PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
            return NULL;
        }
        return PyInt_FromLong((unsigned char)(self->ob_bytes[i]));
    }
    else if (PySlice_Check(index)) {
        Py_ssize_t start, stop, step, slicelength, cur, i;
        if (PySlice_GetIndicesEx((PySliceObject *)index,
                                 PyByteArray_GET_SIZE(self),
                                 &start, &stop, &step, &slicelength) < 0) {
            return NULL;
        }

        if (slicelength <= 0)
            return PyByteArray_FromStringAndSize("", 0);
        else if (step == 1) {
            return PyByteArray_FromStringAndSize(self->ob_bytes + start,
                                             slicelength);
        }
        else {
            char *source_buf = PyByteArray_AS_STRING(self);
            char *result_buf = (char *)PyMem_Malloc(slicelength);
            PyObject *result;

            if (result_buf == NULL)
                return PyErr_NoMemory();

            for (cur = start, i = 0; i < slicelength;
                 cur += step, i++) {
                     result_buf[i] = source_buf[cur];
            }
            result = PyByteArray_FromStringAndSize(result_buf, slicelength);
            PyMem_Free(result_buf);
            return result;
        }
    }
    else {
        PyErr_SetString(PyExc_TypeError, "bytearray indices must be integers");
        return NULL;
    }
}

static int
bytes_setslice(PyByteArrayObject *self, Py_ssize_t lo, Py_ssize_t hi,
               PyObject *values)
{
    Py_ssize_t avail, needed;
    void *bytes;
    Py_buffer vbytes;
    int res = 0;

    vbytes.len = -1;
    if (values == (PyObject *)self) {
        /* Make a copy and call this function recursively */
        int err;
        values = PyByteArray_FromObject(values);
        if (values == NULL)
            return -1;
        err = bytes_setslice(self, lo, hi, values);
        Py_DECREF(values);
        return err;
    }
    if (values == NULL) {
        /* del b[lo:hi] */
        bytes = NULL;
        needed = 0;
    }
    else {
            if (_getbuffer(values, &vbytes) < 0) {
                    PyErr_Format(PyExc_TypeError,
                                 "can't set bytearray slice from %.100s",
                                 Py_TYPE(values)->tp_name);
                    return -1;
            }
            needed = vbytes.len;
            bytes = vbytes.buf;
    }

    if (lo < 0)
        lo = 0;
    if (hi < lo)
        hi = lo;
    if (hi > Py_SIZE(self))
        hi = Py_SIZE(self);

    avail = hi - lo;
    if (avail < 0)
        lo = hi = avail = 0;

    if (avail != needed) {
        if (avail > needed) {
            if (!_canresize(self)) {
                res = -1;
                goto finish;
            }
            /*
              0   lo               hi               old_size
              |   |<----avail----->|<-----tomove------>|
              |   |<-needed->|<-----tomove------>|
              0   lo      new_hi              new_size
            */
            memmove(self->ob_bytes + lo + needed, self->ob_bytes + hi,
                    Py_SIZE(self) - hi);
        }
        /* XXX(nnorwitz): need to verify this can't overflow! */
        if (PyByteArray_Resize((PyObject *)self,
                           Py_SIZE(self) + needed - avail) < 0) {
                res = -1;
                goto finish;
        }
        if (avail < needed) {
            /*
              0   lo        hi               old_size
              |   |<-avail->|<-----tomove------>|
              |   |<----needed---->|<-----tomove------>|
              0   lo            new_hi              new_size
             */
            memmove(self->ob_bytes + lo + needed, self->ob_bytes + hi,
                    Py_SIZE(self) - lo - needed);
        }
    }

    if (needed > 0)
        memcpy(self->ob_bytes + lo, bytes, needed);


 finish:
    if (vbytes.len != -1)
            PyBuffer_Release(&vbytes);
    return res;
}

static int
bytes_setitem(PyByteArrayObject *self, Py_ssize_t i, PyObject *value)
{
    int ival;

    if (i < 0)
        i += Py_SIZE(self);

    if (i < 0 || i >= Py_SIZE(self)) {
        PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
        return -1;
    }

    if (value == NULL)
        return bytes_setslice(self, i, i+1, NULL);

    if (!_getbytevalue(value, &ival))
        return -1;

    self->ob_bytes[i] = ival;
    return 0;
}

static int
bytes_ass_subscript(PyByteArrayObject *self, PyObject *index, PyObject *values)
{
    Py_ssize_t start, stop, step, slicelen, needed;
    char *bytes;

    if (PyIndex_Check(index)) {
        Py_ssize_t i = PyNumber_AsSsize_t(index, PyExc_IndexError);

        if (i == -1 && PyErr_Occurred())
            return -1;

        if (i < 0)
            i += PyByteArray_GET_SIZE(self);

        if (i < 0 || i >= Py_SIZE(self)) {
            PyErr_SetString(PyExc_IndexError, "bytearray index out of range");
            return -1;
        }

        if (values == NULL) {
            /* Fall through to slice assignment */
            start = i;
            stop = i + 1;
            step = 1;
            slicelen = 1;
        }
        else {
            int ival;
            if (!_getbytevalue(values, &ival))
                return -1;
            self->ob_bytes[i] = (char)ival;
            return 0;
        }
    }
    else if (PySlice_Check(index)) {
        if (PySlice_GetIndicesEx((PySliceObject *)index,
                                 PyByteArray_GET_SIZE(self),
                                 &start, &stop, &step, &slicelen) < 0) {
            return -1;
        }
    }
    else {
        PyErr_SetString(PyExc_TypeError, "bytearray indices must be integer");
        return -1;
    }

    if (values == NULL) {
        bytes = NULL;
        needed = 0;
    }
    else if (values == (PyObject *)self || !PyByteArray_Check(values)) {
        /* Make a copy an call this function recursively */
        int err;
        values = PyByteArray_FromObject(values);
        if (values == NULL)
            return -1;
        err = bytes_ass_subscript(self, index, values);
        Py_DECREF(values);
        return err;
    }
    else {
        assert(PyByteArray_Check(values));
        bytes = ((PyByteArrayObject *)values)->ob_bytes;
        needed = Py_SIZE(values);
    }
    /* Make sure b[5:2] = ... inserts before 5, not before 2. */
    if ((step < 0 && start < stop) ||
        (step > 0 && start > stop))
        stop = start;
    if (step == 1) {
        if (slicelen != needed) {
            if (!_canresize(self))
                return -1;
            if (slicelen > needed) {
                /*
                  0   start           stop              old_size
                  |   |<---slicelen--->|<-----tomove------>|
                  |   |<-needed->|<-----tomove------>|
                  0   lo      new_hi              new_size
                */
                memmove(self->ob_bytes + start + needed, self->ob_bytes + stop,
                        Py_SIZE(self) - stop);
            }
            if (PyByteArray_Resize((PyObject *)self,
                               Py_SIZE(self) + needed - slicelen) < 0)
                return -1;
            if (slicelen < needed) {
                /*
                  0   lo        hi               old_size
                  |   |<-avail->|<-----tomove------>|
                  |   |<----needed---->|<-----tomove------>|
                  0   lo            new_hi              new_size
                 */
                memmove(self->ob_bytes + start + needed, self->ob_bytes + stop,
                        Py_SIZE(self) - start - needed);
            }
        }

        if (needed > 0)
            memcpy(self->ob_bytes + start, bytes, needed);

        return 0;
    }
    else {
        if (needed == 0) {
            /* Delete slice */
            Py_ssize_t cur, i;

            if (!_canresize(self))
                return -1;
            if (step < 0) {
                stop = start + 1;
                start = stop + step * (slicelen - 1) - 1;
                step = -step;
            }
            for (cur = start, i = 0;
                 i < slicelen; cur += step, i++) {
                Py_ssize_t lim = step - 1;

                if (cur + step >= PyByteArray_GET_SIZE(self))
                    lim = PyByteArray_GET_SIZE(self) - cur - 1;

                memmove(self->ob_bytes + cur - i,
                        self->ob_bytes + cur + 1, lim);
            }
            /* Move the tail of the bytes, in one chunk */
            cur = start + slicelen*step;
            if (cur < PyByteArray_GET_SIZE(self)) {
                memmove(self->ob_bytes + cur - slicelen,
                        self->ob_bytes + cur,
                        PyByteArray_GET_SIZE(self) - cur);
            }
            if (PyByteArray_Resize((PyObject *)self,
                               PyByteArray_GET_SIZE(self) - slicelen) < 0)
                return -1;

            return 0;
        }
        else {
            /* Assign slice */
            Py_ssize_t cur, i;

            if (needed != slicelen) {
                PyErr_Format(PyExc_ValueError,
                             "attempt to assign bytes of size %zd "
                             "to extended slice of size %zd",
                             needed, slicelen);
                return -1;
            }
            for (cur = start, i = 0; i < slicelen; cur += step, i++)
                self->ob_bytes[cur] = bytes[i];
            return 0;
        }
    }
}

static int
bytes_init(PyByteArrayObject *self, PyObject *args, PyObject *kwds)
{
    static char *kwlist[] = {"source", "encoding", "errors", 0};
    PyObject *arg = NULL;
    const char *encoding = NULL;
    const char *errors = NULL;
    Py_ssize_t count;
    PyObject *it;
    PyObject *(*iternext)(PyObject *);

    if (Py_SIZE(self) != 0) {
        /* Empty previous contents (yes, do this first of all!) */
        if (PyByteArray_Resize((PyObject *)self, 0) < 0)
            return -1;
    }

    /* Parse arguments */
    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oss:bytearray", kwlist,
                                     &arg, &encoding, &errors))
        return -1;

    /* Make a quick exit if no first argument */
    if (arg == NULL) {
        if (encoding != NULL || errors != NULL) {
            PyErr_SetString(PyExc_TypeError,
                            "encoding or errors without sequence argument");
            return -1;
        }
        return 0;
    }

    if (PyBytes_Check(arg)) {
        PyObject *new, *encoded;
        if (encoding != NULL) {
            encoded = PyCodec_Encode(arg, encoding, errors);
            if (encoded == NULL)
                return -1;
            assert(PyBytes_Check(encoded));
        }
        else {
            encoded = arg;
            Py_INCREF(arg);
        }
        new = bytes_iconcat(self, arg);
        Py_DECREF(encoded);
        if (new == NULL)
            return -1;
        Py_DECREF(new);
        return 0;
    }

    if (PyUnicode_Check(arg)) {
        /* Encode via the codec registry */
        PyObject *encoded, *new;
        if (encoding == NULL) {
            PyErr_SetString(PyExc_TypeError,
                            "unicode argument without an encoding");
            return -1;
        }
        encoded = PyCodec_Encode(arg, encoding, errors);
        if (encoded == NULL)
            return -1;
        assert(PyBytes_Check(encoded));
        new = bytes_iconcat(self, encoded);
        Py_DECREF(encoded);
        if (new == NULL)
            return -1;
        Py_DECREF(new);
        return 0;
    }

    /* If it's not unicode, there can't be encoding or errors */
    if (encoding != NULL || errors != NULL) {
        PyErr_SetString(PyExc_TypeError,
                        "encoding or errors without a string argument");
        return -1;
    }

    /* Is it an int? */
    count = PyNumber_AsSsize_t(arg, PyExc_ValueError);
    if (count == -1 && PyErr_Occurred())
        PyErr_Clear();
    else {
        if (count < 0) {
            PyErr_SetString(PyExc_ValueError, "negative count");
            return -1;
        }
        if (count > 0) {
            if (PyByteArray_Resize((PyObject *)self, count))
                return -1;
            memset(self->ob_bytes, 0, count);
        }
        return 0;
    }

    /* Use the buffer API */
    if (PyObject_CheckBuffer(arg)) {
        Py_ssize_t size;
        Py_buffer view;
        if (PyObject_GetBuffer(arg, &view, PyBUF_FULL_RO) < 0)
            return -1;
        size = view.len;
        if (PyByteArray_Resize((PyObject *)self, size) < 0) goto fail;
        if (PyBuffer_ToContiguous(self->ob_bytes, &view, size, 'C') < 0)
                goto fail;
        PyBuffer_Release(&view);
        return 0;
    fail:
        PyBuffer_Release(&view);
        return -1;
    }

    /* XXX Optimize this if the arguments is a list, tuple */

    /* Get the iterator */
    it = PyObject_GetIter(arg);
    if (it == NULL)
        return -1;
    iternext = *Py_TYPE(it)->tp_iternext;

    /* Run the iterator to exhaustion */
    for (;;) {
        PyObject *item;
        int rc, 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__) */
        rc = _getbytevalue(item, &value);
        Py_DECREF(item);
        if (!rc)
            goto error;

        /* Append the byte */
        if (Py_SIZE(self) < self->ob_alloc)
            Py_SIZE(self)++;
        else if (PyByteArray_Resize((PyObject *)self, Py_SIZE(self)+1) < 0)
            goto error;
        self->ob_bytes[Py_SIZE(self)-1] = value;
    }

    /* Clean up and return success */
    Py_DECREF(it);
    return 0;

 error:
    /* Error handling when it != NULL */
    Py_DECREF(it);
    return -1;
}

/* Mostly copied from string_repr, but without the
   "smart quote" functionality. */
static PyObject *
bytes_repr(PyByteArrayObject *self)
{
    static const char *hexdigits = "0123456789abcdef";
    const char *quote_prefix = "bytearray(b";
    const char *quote_postfix = ")";
    Py_ssize_t length = Py_SIZE(self);
    /* 14 == strlen(quote_prefix) + 2 + strlen(quote_postfix) */
    size_t newsize = 14 + 4 * length;
    PyObject *v;
    if (newsize > PY_SSIZE_T_MAX || newsize / 4 - 3 != length) {
        PyErr_SetString(PyExc_OverflowError,
            "bytearray object is too large to make repr");
        return NULL;
    }
    v = PyUnicode_FromUnicode(NULL, newsize);
    if (v == NULL) {
        return NULL;
    }
    else {
        register Py_ssize_t i;
        register Py_UNICODE c;
        register Py_UNICODE *p;
        int quote;

        /* Figure out which quote to use; single is preferred */
        quote = '\'';
        {
            char *test, *start;
            start = PyByteArray_AS_STRING(self);
            for (test = start; test < start+length; ++test) {
                if (*test == '"') {
                    quote = '\''; /* back to single */
                    goto decided;
                }
                else if (*test == '\'')
                    quote = '"';
            }
          decided:
            ;
        }

        p = PyUnicode_AS_UNICODE(v);
        while (*quote_prefix)
            *p++ = *quote_prefix++;
        *p++ = quote;

        for (i = 0; i < length; i++) {
            /* There's at least enough room for a hex escape
               and a closing quote. */
            assert(newsize - (p - PyUnicode_AS_UNICODE(v)) >= 5);
            c = self->ob_bytes[i];
            if (c == '\'' || c == '\\')
                *p++ = '\\', *p++ = c;
            else if (c == '\t')
                *p++ = '\\', *p++ = 't';
            else if (c == '\n')
                *p++ = '\\', *p++ = 'n';
            else if (c == '\r')
                *p++ = '\\', *p++ = 'r';
            else if (c == 0)
                *p++ = '\\', *p++ = 'x', *p++ = '0', *p++ = '0';
            else if (c < ' ' || c >= 0x7f) {
                *p++ = '\\';
                *p++ = 'x';
                *p++ = hexdigits[(c & 0xf0) >> 4];
                *p++ = hexdigits[c & 0xf];
            }
            else
                *p++ = c;
        }
        assert(newsize - (p - PyUnicode_AS_UNICODE(v)) >= 1);
        *p++ = quote;
        while (*quote_postfix) {
           *p++ = *quote_postfix++;
        }
        *p = '\0';
        if (PyUnicode_Resize(&v, (p - PyUnicode_AS_UNICODE(v)))) {
            Py_DECREF(v);
            return NULL;
        }
        return v;
    }
}

static PyObject *
bytes_str(PyObject *op)
{
#if 0
    if (Py_BytesWarningFlag) {
        if (PyErr_WarnEx(PyExc_BytesWarning,
                 "str() on a bytearray instance", 1))
            return NULL;
    }
    return bytes_repr((PyByteArrayObject*)op);
#endif
    return PyBytes_FromStringAndSize(((PyByteArrayObject*)op)->ob_bytes, Py_SIZE(op));
}

static PyObject *
bytes_richcompare(PyObject *self, PyObject *other, int op)
{
    Py_ssize_t self_size, other_size;
    Py_buffer self_bytes, other_bytes;
    PyObject *res;
    Py_ssize_t minsize;
    int cmp;

    /* Bytes can be compared to anything that supports the (binary)
       buffer API.  Except that a comparison with Unicode is always an
       error, even if the comparison is for equality. */
    if (PyObject_IsInstance(self, (PyObject*)&PyUnicode_Type) ||
        PyObject_IsInstance(other, (PyObject*)&PyUnicode_Type)) {
        if (Py_BytesWarningFlag && op == Py_EQ) {
            if (PyErr_WarnEx(PyExc_BytesWarning,
                            "Comparsion between bytearray and string", 1))
                return NULL;
        }

        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }

    self_size = _getbuffer(self, &self_bytes);
    if (self_size < 0) {
        PyErr_Clear();
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }

    other_size = _getbuffer(other, &other_bytes);
    if (other_size < 0) {
        PyErr_Clear();
        PyBuffer_Release(&self_bytes);
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }

    if (self_size != other_size && (op == Py_EQ || op == Py_NE)) {
        /* Shortcut: if the lengths differ, the objects differ */
        cmp = (op == Py_NE);
    }
    else {
        minsize = self_size;
        if (other_size < minsize)
            minsize = other_size;

        cmp = memcmp(self_bytes.buf, other_bytes.buf, minsize);
        /* In ISO C, memcmp() guarantees to use unsigned bytes! */

        if (cmp == 0) {
            if (self_size < other_size)
                cmp = -1;
            else if (self_size > other_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;
    PyBuffer_Release(&self_bytes);
    PyBuffer_Release(&other_bytes);
    Py_INCREF(res);
    return res;
}

static void
bytes_dealloc(PyByteArrayObject *self)
{
	if (self->ob_exports > 0) {
		PyErr_SetString(PyExc_SystemError,
                        "deallocated bytearray object has exported buffers");
		PyErr_Print();
	}
    if (self->ob_bytes != 0) {
        PyMem_Free(self->ob_bytes);
    }
    Py_TYPE(self)->tp_free((PyObject *)self);
}


/* -------------------------------------------------------------------- */
/* Methods */

#define STRINGLIB_CHAR char
#define STRINGLIB_CMP memcmp
#define STRINGLIB_LEN PyByteArray_GET_SIZE
#define STRINGLIB_STR PyByteArray_AS_STRING
#define STRINGLIB_NEW PyByteArray_FromStringAndSize
#define STRINGLIB_EMPTY nullbytes
#define STRINGLIB_CHECK_EXACT PyByteArray_CheckExact
#define STRINGLIB_MUTABLE 1
#define FROM_BYTEARRAY 1

#include "stringlib/fastsearch.h"
#include "stringlib/count.h"
#include "stringlib/find.h"
#include "stringlib/partition.h"
#include "stringlib/ctype.h"
#include "stringlib/transmogrify.h"


/* The following Py_LOCAL_INLINE and Py_LOCAL functions
were copied from the old char* style string object. */

Py_LOCAL_INLINE(void)
_adjust_indices(Py_ssize_t *start, Py_ssize_t *end, Py_ssize_t len)
{
    if (*end > len)
        *end = len;
    else if (*end < 0)
        *end += len;
    if (*end < 0)
        *end = 0;
    if (*start < 0)
        *start += len;
    if (*start < 0)
        *start = 0;
}


Py_LOCAL_INLINE(Py_ssize_t)
bytes_find_internal(PyByteArrayObject *self, PyObject *args, int dir)
{
    PyObject *subobj;
    Py_buffer subbuf;
    Py_ssize_t start=0, end=PY_SSIZE_T_MAX;
    Py_ssize_t res;

    if (!PyArg_ParseTuple(args, "O|O&O&:find/rfind/index/rindex", &subobj,
        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return -2;
    if (_getbuffer(subobj, &subbuf) < 0)
        return -2;
    if (dir > 0)
        res = stringlib_find_slice(
            PyByteArray_AS_STRING(self), PyByteArray_GET_SIZE(self),
            subbuf.buf, subbuf.len, start, end);
    else
        res = stringlib_rfind_slice(
            PyByteArray_AS_STRING(self), PyByteArray_GET_SIZE(self),
            subbuf.buf, subbuf.len, start, end);
    PyBuffer_Release(&subbuf);
    return res;
}

PyDoc_STRVAR(find__doc__,
"B.find(sub [,start [,end]]) -> int\n\
\n\
Return the lowest index in B where subsection sub is found,\n\
such that sub is contained within s[start,end].  Optional\n\
arguments start and end are interpreted as in slice notation.\n\
\n\
Return -1 on failure.");

static PyObject *
bytes_find(PyByteArrayObject *self, PyObject *args)
{
    Py_ssize_t result = bytes_find_internal(self, args, +1);
    if (result == -2)
        return NULL;
    return PyInt_FromSsize_t(result);
}

PyDoc_STRVAR(count__doc__,
"B.count(sub [,start [,end]]) -> int\n\
\n\
Return the number of non-overlapping occurrences of subsection sub in\n\
bytes B[start:end].  Optional arguments start and end are interpreted\n\
as in slice notation.");

static PyObject *
bytes_count(PyByteArrayObject *self, PyObject *args)
{
    PyObject *sub_obj;
    const char *str = PyByteArray_AS_STRING(self);
    Py_ssize_t start = 0, end = PY_SSIZE_T_MAX;
    Py_buffer vsub;
    PyObject *count_obj;

    if (!PyArg_ParseTuple(args, "O|O&O&:count", &sub_obj,
        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;

    if (_getbuffer(sub_obj, &vsub) < 0)
        return NULL;

    _adjust_indices(&start, &end, PyByteArray_GET_SIZE(self));

    count_obj = PyInt_FromSsize_t(
        stringlib_count(str + start, end - start, vsub.buf, vsub.len)
        );
    PyBuffer_Release(&vsub);
    return count_obj;
}


PyDoc_STRVAR(index__doc__,
"B.index(sub [,start [,end]]) -> int\n\
\n\
Like B.find() but raise ValueError when the subsection is not found.");

static PyObject *
bytes_index(PyByteArrayObject *self, PyObject *args)
{
    Py_ssize_t result = bytes_find_internal(self, args, +1);
    if (result == -2)
        return NULL;
    if (result == -1) {
        PyErr_SetString(PyExc_ValueError,
                        "subsection not found");
        return NULL;
    }
    return PyInt_FromSsize_t(result);
}


PyDoc_STRVAR(rfind__doc__,
"B.rfind(sub [,start [,end]]) -> int\n\
\n\
Return the highest index in B where subsection sub is found,\n\
such that sub is contained within s[start,end].  Optional\n\
arguments start and end are interpreted as in slice notation.\n\
\n\
Return -1 on failure.");

static PyObject *
bytes_rfind(PyByteArrayObject *self, PyObject *args)
{
    Py_ssize_t result = bytes_find_internal(self, args, -1);
    if (result == -2)
        return NULL;
    return PyInt_FromSsize_t(result);
}


PyDoc_STRVAR(rindex__doc__,
"B.rindex(sub [,start [,end]]) -> int\n\
\n\
Like B.rfind() but raise ValueError when the subsection is not found.");

static PyObject *
bytes_rindex(PyByteArrayObject *self, PyObject *args)
{
    Py_ssize_t result = bytes_find_internal(self, args, -1);
    if (result == -2)
        return NULL;
    if (result == -1) {
        PyErr_SetString(PyExc_ValueError,
                        "subsection not found");
        return NULL;
    }
    return PyInt_FromSsize_t(result);
}


static int
bytes_contains(PyObject *self, PyObject *arg)
{
    Py_ssize_t ival = PyNumber_AsSsize_t(arg, PyExc_ValueError);
    if (ival == -1 && PyErr_Occurred()) {
        Py_buffer varg;
        int pos;
        PyErr_Clear();
        if (_getbuffer(arg, &varg) < 0)
            return -1;
        pos = stringlib_find(PyByteArray_AS_STRING(self), Py_SIZE(self),
                             varg.buf, varg.len, 0);
        PyBuffer_Release(&varg);
        return pos >= 0;
    }
    if (ival < 0 || ival >= 256) {
        PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
        return -1;
    }

    return memchr(PyByteArray_AS_STRING(self), ival, Py_SIZE(self)) != NULL;
}


/* Matches the end (direction >= 0) or start (direction < 0) of self
 * against substr, using the start and end arguments. Returns
 * -1 on error, 0 if not found and 1 if found.
 */
Py_LOCAL(int)
_bytes_tailmatch(PyByteArrayObject *self, PyObject *substr, Py_ssize_t start,
                 Py_ssize_t end, int direction)
{
    Py_ssize_t len = PyByteArray_GET_SIZE(self);
    const char* str;
    Py_buffer vsubstr;
    int rv = 0;

    str = PyByteArray_AS_STRING(self);

    if (_getbuffer(substr, &vsubstr) < 0)
        return -1;

    _adjust_indices(&start, &end, len);

    if (direction < 0) {
        /* startswith */
        if (start+vsubstr.len > len) {
            goto done;
        }
    } else {
        /* endswith */
        if (end-start < vsubstr.len || start > len) {
            goto done;
        }

        if (end-vsubstr.len > start)
            start = end - vsubstr.len;
    }
    if (end-start >= vsubstr.len)
        rv = ! memcmp(str+start, vsubstr.buf, vsubstr.len);

done:
    PyBuffer_Release(&vsubstr);
    return rv;
}


PyDoc_STRVAR(startswith__doc__,
"B.startswith(prefix [,start [,end]]) -> bool\n\
\n\
Return True if B starts with the specified prefix, False otherwise.\n\
With optional start, test B beginning at that position.\n\
With optional end, stop comparing B at that position.\n\
prefix can also be a tuple of strings to try.");

static PyObject *
bytes_startswith(PyByteArrayObject *self, PyObject *args)
{
    Py_ssize_t start = 0;
    Py_ssize_t end = PY_SSIZE_T_MAX;
    PyObject *subobj;
    int result;

    if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &subobj,
        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    if (PyTuple_Check(subobj)) {
        Py_ssize_t i;
        for (i = 0; i < PyTuple_GET_SIZE(subobj); i++) {
            result = _bytes_tailmatch(self,
                                      PyTuple_GET_ITEM(subobj, i),
                                      start, end, -1);
            if (result == -1)
                return NULL;
            else if (result) {
                Py_RETURN_TRUE;
            }
        }
        Py_RETURN_FALSE;
    }
    result = _bytes_tailmatch(self, subobj, start, end, -1);
    if (result == -1)
        return NULL;
    else
        return PyBool_FromLong(result);
}

PyDoc_STRVAR(endswith__doc__,
"B.endswith(suffix [,start [,end]]) -> bool\n\
\n\
Return True if B ends with the specified suffix, False otherwise.\n\
With optional start, test B beginning at that position.\n\
With optional end, stop comparing B at that position.\n\
suffix can also be a tuple of strings to try.");

static PyObject *
bytes_endswith(PyByteArrayObject *self, PyObject *args)
{
    Py_ssize_t start = 0;
    Py_ssize_t end = PY_SSIZE_T_MAX;
    PyObject *subobj;
    int result;

    if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &subobj,
        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
        return NULL;
    if (PyTuple_Check(subobj)) {
        Py_ssize_t i;
        for (i = 0; i < PyTuple_GET_SIZE(subobj); i++) {
            result = _bytes_tailmatch(self,
                                      PyTuple_GET_ITEM(subobj, i),
                                      start, end, +1);
            if (result == -1)
                return NULL;
            else if (result) {
                Py_RETURN_TRUE;
            }
        }
        Py_RETURN_FALSE;
    }
    result = _bytes_tailmatch(self, subobj, start, end, +1);
    if (result == -1)
        return NULL;
    else
        return PyBool_FromLong(result);
}


PyDoc_STRVAR(translate__doc__,
"B.translate(table[, deletechars]) -> bytearray\n\
\n\
Return a copy of B, where all characters occurring in the\n\
optional argument deletechars are removed, and the remaining\n\
characters have been mapped through the given translation\n\
table, which must be a bytes object of length 256.");

static PyObject *
bytes_translate(PyByteArrayObject *self, PyObject *args)
{
    register char *input, *output;
    register const char *table;
    register Py_ssize_t i, c;
    PyObject *input_obj = (PyObject*)self;
    const char *output_start;
    Py_ssize_t inlen;
    PyObject *result;
    int trans_table[256];
    PyObject *tableobj, *delobj = NULL;
    Py_buffer vtable, vdel;

    if (!PyArg_UnpackTuple(args, "translate", 1, 2,
                           &tableobj, &delobj))
          return NULL;

    if (_getbuffer(tableobj, &vtable) < 0)
        return NULL;

    if (vtable.len != 256) {
        PyErr_SetString(PyExc_ValueError,
                        "translation table must be 256 characters long");
        PyBuffer_Release(&vtable);
        return NULL;
    }

    if (delobj != NULL) {
        if (_getbuffer(delobj, &vdel) < 0) {
            PyBuffer_Release(&vtable);
	    return NULL;
        }
    }
    else {
        vdel.buf = NULL;
        vdel.len = 0;
    }

    table = (const char *)vtable.buf;
    inlen = PyByteArray_GET_SIZE(input_obj);
    result = PyByteArray_FromStringAndSize((char *)NULL, inlen);
    if (result == NULL)
        goto done;
    output_start = output = PyByteArray_AsString(result);
    input = PyByteArray_AS_STRING(input_obj);

    if (vdel.len == 0) {
        /* If no deletions are required, use faster code */
        for (i = inlen; --i >= 0; ) {
            c = Py_CHARMASK(*input++);
            *output++ = table[c];
        }
        goto done;
    }
    
    for (i = 0; i < 256; i++)
        trans_table[i] = Py_CHARMASK(table[i]);

    for (i = 0; i < vdel.len; i++)
        trans_table[(int) Py_CHARMASK( ((unsigned char*)vdel.buf)[i] )] = -1;

    for (i = inlen; --i >= 0; ) {
        c = Py_CHARMASK(*input++);
        if (trans_table[c] != -1)
            if (Py_CHARMASK(*output++ = (char)trans_table[c]) == c)
                    continue;
    }
    /* Fix the size of the resulting string */
    if (inlen > 0)
        PyByteArray_Resize(result, output - output_start);

done:
    PyBuffer_Release(&vtable);
    if (delobj != NULL)
        PyBuffer_Release(&vdel);
    return result;
}


#define FORWARD 1
#define REVERSE -1

/* find and count characters and substrings */

#define findchar(target, target_len, c)                         \
  ((char *)memchr((const void *)(target), c, target_len))

/* Don't call if length < 2 */
#define Py_STRING_MATCH(target, offset, pattern, length)        \
  (target[offset] == pattern[0] &&                              \
   target[offset+length-1] == pattern[length-1] &&              \
   !memcmp(target+offset+1, pattern+1, length-2) )


/* Bytes ops must return a string, create a copy */
Py_LOCAL(PyByteArrayObject *)
return_self(PyByteArrayObject *self)
{
    return (PyByteArrayObject *)PyByteArray_FromStringAndSize(
            PyByteArray_AS_STRING(self),
            PyByteArray_GET_SIZE(self));
}

Py_LOCAL_INLINE(Py_ssize_t)
countchar(const char *target, Py_ssize_t target_len, char c, Py_ssize_t maxcount)
{
    Py_ssize_t count=0;
    const char *start=target;
    const char *end=target+target_len;

    while ( (start=findchar(start, end-start, c)) != NULL ) {
        count++;
        if (count >= maxcount)
            break;
        start += 1;
    }
    return count;
}

Py_LOCAL(Py_ssize_t)
findstring(const char *target, Py_ssize_t target_len,
           const char *pattern, Py_ssize_t pattern_len,
           Py_ssize_t start,
           Py_ssize_t end,
           int direction)
{
    if (start < 0) {
        start += target_len;
        if (start < 0)
            start = 0;
    }
    if (end > target_len) {
        end = target_len;
    } else if (end < 0) {
        end += target_len;
        if (end < 0)
            end = 0;
    }

    /* zero-length substrings always match at the first attempt */
    if (pattern_len == 0)
        return (direction > 0) ? start : end;

    end -= pattern_len;

    if (direction < 0) {
        for (; end >= start; end--)
            if (Py_STRING_MATCH(target, end, pattern, pattern_len))
                return end;
    } else {
        for (; start <= end; start++)
            if (Py_STRING_MATCH(target, start, pattern, pattern_len))
                return start;
    }
    return -1;
}

Py_LOCAL_INLINE(Py_ssize_t)
countstring(const char *target, Py_ssize_t target_len,
            const char *pattern, Py_ssize_t pattern_len,
            Py_ssize_t start,
            Py_ssize_t end,
            int direction, Py_ssize_t maxcount)
{
    Py_ssize_t count=0;

    if (start < 0) {
        start += target_len;
        if (start < 0)
            start = 0;
    }
    if (end > target_len) {
        end = target_len;
    } else if (end < 0) {
        end += target_len;
        if (end < 0)
            end = 0;
    }

    /* zero-length substrings match everywhere */
    if (pattern_len == 0 || maxcount == 0) {
        if (target_len+1 < maxcount)
            return target_len+1;
        return maxcount;
    }

    end -= pattern_len;
    if (direction < 0) {
        for (; (end >= start); end--)
            if (Py_STRING_MATCH(target, end, pattern, pattern_len)) {
                count++;
                if (--maxcount <= 0) break;
                end -= pattern_len-1;
            }
    } else {
        for (; (start <= end); start++)
            if (Py_STRING_MATCH(target, start, pattern, pattern_len)) {
                count++;
                if (--maxcount <= 0)
                    break;
                start += pattern_len-1;
            }
    }
    return count;
}


/* Algorithms for different cases of string replacement */

/* len(self)>=1, from="", len(to)>=1, maxcount>=1 */
Py_LOCAL(PyByteArrayObject *)
replace_interleave(PyByteArrayObject *self,
                   const char *to_s, Py_ssize_t to_len,
                   Py_ssize_t maxcount)
{
    char *self_s, *result_s;
    Py_ssize_t self_len, result_len;
    Py_ssize_t count, i, product;
    PyByteArrayObject *result;

    self_len = PyByteArray_GET_SIZE(self);

    /* 1 at the end plus 1 after every character */
    count = self_len+1;
    if (maxcount < count)
        count = maxcount;

    /* Check for overflow */
    /*   result_len = count * to_len + self_len; */
    product = count * to_len;
    if (product / to_len != count) {
        PyErr_SetString(PyExc_OverflowError,
                        "replace string is too long");
        return NULL;
    }
    result_len = product + self_len;
    if (result_len < 0) {
        PyErr_SetString(PyExc_OverflowError,
                        "replace string is too long");
        return NULL;
    }

    if (! (result = (PyByteArrayObject *)
                     PyByteArray_FromStringAndSize(NULL, result_len)) )
        return NULL;

    self_s = PyByteArray_AS_STRING(self);
    result_s = PyByteArray_AS_STRING(result);

    /* TODO: special case single character, which doesn't need memcpy */

    /* Lay the first one down (guaranteed this will occur) */
    Py_MEMCPY(result_s, to_s, to_len);
    result_s += to_len;
    count -= 1;

    for (i=0; i<count; i++) {
        *result_s++ = *self_s++;
        Py_MEMCPY(result_s, to_s, to_len);
        result_s += to_len;
    }

    /* Copy the rest of the original string */
    Py_MEMCPY(result_s, self_s, self_len-i);

    return result;
}

/* Special case for deleting a single character */
/* len(self)>=1, len(from)==1, to="", maxcount>=1 */
Py_LOCAL(PyByteArrayObject *)
replace_delete_single_character(PyByteArrayObject *self,
                                char from_c, Py_ssize_t maxcount)
{
    char *self_s, *result_s;
    char *start, *next, *end;
    Py_ssize_t self_len, result_len;
    Py_ssize_t count;
    PyByteArrayObject *result;

    self_len = PyByteArray_GET_SIZE(self);
    self_s = PyByteArray_AS_STRING(self);

    count = countchar(self_s, self_len, from_c, maxcount);
    if (count == 0) {
        return return_self(self);
    }

    result_len = self_len - count;  /* from_len == 1 */
    assert(result_len>=0);

    if ( (result = (PyByteArrayObject *)
                    PyByteArray_FromStringAndSize(NULL, result_len)) == NULL)
        return NULL;
    result_s = PyByteArray_AS_STRING(result);

    start = self_s;
    end = self_s + self_len;
    while (count-- > 0) {
        next = findchar(start, end-start, from_c);
        if (next == NULL)
            break;
        Py_MEMCPY(result_s, start, next-start);
        result_s += (next-start);
        start = next+1;
    }
    Py_MEMCPY(result_s, start, end-start);

    return result;
}

/* len(self)>=1, len(from)>=2, to="", maxcount>=1 */

Py_LOCAL(PyByteArrayObject *)
replace_delete_substring(PyByteArrayObject *self,
                         const char *from_s, Py_ssize_t from_len,
                         Py_ssize_t maxcount)
{
    char *self_s, *result_s;
    char *start, *next, *end;
    Py_ssize_t self_len, result_len;
    Py_ssize_t count, offset;
    PyByteArrayObject *result;

    self_len = PyByteArray_GET_SIZE(self);
    self_s = PyByteArray_AS_STRING(self);

    count = countstring(self_s, self_len,
                        from_s, from_len,
                        0, self_len, 1,
                        maxcount);

    if (count == 0) {
        /* no matches */
        return return_self(self);
    }

    result_len = self_len - (count * from_len);
    assert (result_len>=0);

    if ( (result = (PyByteArrayObject *)
        PyByteArray_FromStringAndSize(NULL, result_len)) == NULL )
            return NULL;

    result_s = PyByteArray_AS_STRING(result);

    start = self_s;
    end = self_s + self_len;
    while (count-- > 0) {
        offset = findstring(start, end-start,
                            from_s, from_len,
                            0, end-start, FORWARD);
        if (offset == -1)
            break;
        next = start + offset;

        Py_MEMCPY(result_s, start, next-start);

        r…