_sre.c

python s60 1.4.5版本的源代码

    self->flags = flags;

    self->groups = groups;

    Py_XINCREF(groupindex);
    self->groupindex = groupindex;

    Py_XINCREF(indexgroup);
    self->indexgroup = indexgroup;

    return (PyObject*) self;
}

static PyObject *
sre_codesize(PyObject* self, PyObject* args)
{
    return Py_BuildValue("i", sizeof(SRE_CODE));
}

static PyObject *
sre_getlower(PyObject* self, PyObject* args)
{
    int character, flags;
    if (!PyArg_ParseTuple(args, "ii", &character, &flags))
        return NULL;
    if (flags & SRE_FLAG_LOCALE)
        return Py_BuildValue("i", sre_lower_locale(character));
    if (flags & SRE_FLAG_UNICODE)
#if defined(HAVE_UNICODE)
        return Py_BuildValue("i", sre_lower_unicode(character));
#else
        return Py_BuildValue("i", sre_lower_locale(character));
#endif
    return Py_BuildValue("i", sre_lower(character));
}

LOCAL(void)
state_reset(SRE_STATE* state)
{
    int i;

    state->lastmark = 0;

    /* FIXME: dynamic! */
    for (i = 0; i < SRE_MARK_SIZE; i++)
        state->mark[i] = NULL;

    state->lastindex = -1;

    state->repeat = NULL;

    mark_fini(state);
}

static void*
getstring(PyObject* string, int* p_length, int* p_charsize)
{
    /* given a python object, return a data pointer, a length (in
       characters), and a character size.  return NULL if the object
       is not a string (or not compatible) */
    
    PyBufferProcs *buffer;
    int size, bytes, charsize;
    void* ptr;

#if defined(HAVE_UNICODE)
    if (PyUnicode_Check(string)) {
        /* unicode strings doesn't always support the buffer interface */
        ptr = (void*) PyUnicode_AS_DATA(string);
        bytes = PyUnicode_GET_DATA_SIZE(string);
        size = PyUnicode_GET_SIZE(string);
        charsize = sizeof(Py_UNICODE);

    } else {
#endif

    /* get pointer to string buffer */
    // XXX:CW32
    buffer = (PyBufferProcs *)string->ob_type->tp_as_buffer;
    if (!buffer || !buffer->bf_getreadbuffer || !buffer->bf_getsegcount ||
        buffer->bf_getsegcount(string, NULL) != 1) {
        PyErr_SetString(PyExc_TypeError, "expected string or buffer");
        return NULL;
    }

    /* determine buffer size */
    bytes = buffer->bf_getreadbuffer(string, 0, &ptr);
    if (bytes < 0) {
        PyErr_SetString(PyExc_TypeError, "buffer has negative size");
        return NULL;
    }

    /* determine character size */
#if PY_VERSION_HEX >= 0x01060000
    size = PyObject_Size(string);
#else
    size = PyObject_Length(string);
#endif

    if (PyString_Check(string) || bytes == size)
        charsize = 1;
#if defined(HAVE_UNICODE)
    else if (bytes == (int) (size * sizeof(Py_UNICODE)))
        charsize = sizeof(Py_UNICODE);
#endif
    else {
        PyErr_SetString(PyExc_TypeError, "buffer size mismatch");
        return NULL;
    }

#if defined(HAVE_UNICODE)
    }
#endif

    *p_length = size;
    *p_charsize = charsize;

    return ptr;
}

LOCAL(PyObject*)
state_init(SRE_STATE* state, PatternObject* pattern, PyObject* string,
           int start, int end)
{
    /* prepare state object */

    int length;
    int charsize;
    void* ptr;

    memset(state, 0, sizeof(SRE_STATE));

    state->lastindex = -1;

    ptr = getstring(string, &length, &charsize);
    if (!ptr)
        return NULL;

    /* adjust boundaries */
    if (start < 0)
        start = 0;
    else if (start > length)
        start = length;

    if (end < 0)
        end = 0;
    else if (end > length)
        end = length;

    state->charsize = charsize;

    state->beginning = ptr;

    state->start = (void*) ((char*) ptr + start * state->charsize);
    state->end = (void*) ((char*) ptr + end * state->charsize);

    Py_INCREF(string);
    state->string = string;
    state->pos = start;
    state->endpos = end;

    if (pattern->flags & SRE_FLAG_LOCALE)
        state->lower = sre_lower_locale;
    else if (pattern->flags & SRE_FLAG_UNICODE)
#if defined(HAVE_UNICODE)
        state->lower = sre_lower_unicode;
#else
        state->lower = sre_lower_locale;
#endif
    else
        state->lower = sre_lower;

    return string;
}

LOCAL(void)
state_fini(SRE_STATE* state)
{
    Py_XDECREF(state->string);
    mark_fini(state);
}

/* calculate offset from start of string */
#define STATE_OFFSET(state, member)\
    (((char*)(member) - (char*)(state)->beginning) / (state)->charsize)

LOCAL(PyObject*)
state_getslice(SRE_STATE* state, int index, PyObject* string, int empty)
{
    int i, j;

    index = (index - 1) * 2;

    if (string == Py_None || !state->mark[index] || !state->mark[index+1]) {
        if (empty)
            /* want empty string */
            i = j = 0;
        else {
            Py_INCREF(Py_None);
            return Py_None;
        }
    } else {
        i = STATE_OFFSET(state, state->mark[index]);
        j = STATE_OFFSET(state, state->mark[index+1]);
    }

    return PySequence_GetSlice(string, i, j);
}

static void
pattern_error(int status)
{
    switch (status) {
    case SRE_ERROR_RECURSION_LIMIT:
        PyErr_SetString(
            PyExc_RuntimeError,
            "maximum recursion limit exceeded"
            );
        break;
    case SRE_ERROR_MEMORY:
        PyErr_NoMemory();
        break;
    default:
        /* other error codes indicate compiler/engine bugs */
        PyErr_SetString(
            PyExc_RuntimeError,
            "internal error in regular expression engine"
            );
    }
}

static PyObject*
pattern_new_match(PatternObject* pattern, SRE_STATE* state, int status)
{
    /* create match object (from state object) */

    MatchObject* match;
    int i, j;
    char* base;
    int n;

    if (status > 0) {

        /* create match object (with room for extra group marks) */
        match = PyObject_NEW_VAR(MatchObject, &Match_Type,
                                 2*(pattern->groups+1));
        if (!match)
            return NULL;

        Py_INCREF(pattern);
        match->pattern = pattern;

        Py_INCREF(state->string);
        match->string = state->string;

        match->regs = NULL;
        match->groups = pattern->groups+1;

        /* fill in group slices */

        base = (char*) state->beginning;
        n = state->charsize;

        match->mark[0] = ((char*) state->start - base) / n;
        match->mark[1] = ((char*) state->ptr - base) / n;

        for (i = j = 0; i < pattern->groups; i++, j+=2)
            if (j+1 <= state->lastmark && state->mark[j] && state->mark[j+1]) {
                match->mark[j+2] = ((char*) state->mark[j] - base) / n;
                match->mark[j+3] = ((char*) state->mark[j+1] - base) / n;
            } else
                match->mark[j+2] = match->mark[j+3] = -1; /* undefined */

        match->pos = state->pos;
        match->endpos = state->endpos;

        match->lastindex = state->lastindex;

        return (PyObject*) match;

    } else if (status == 0) {

        /* no match */
        Py_INCREF(Py_None);
        return Py_None;

    }

    /* internal error */
    pattern_error(status);
    return NULL;
}

static PyObject*
pattern_scanner(PatternObject* pattern, PyObject* args)
{
    /* create search state object */

    ScannerObject* self;

    PyObject* string;
    int start = 0;
    int end = INT_MAX;
    if (!PyArg_ParseTuple(args, "O|ii:scanner", &string, &start, &end))
        return NULL;

    /* create scanner object */
    self = PyObject_NEW(ScannerObject, &Scanner_Type);
    if (!self)
        return NULL;

    string = state_init(&self->state, pattern, string, start, end);
    if (!string) {
        PyObject_DEL(self);
        return NULL;
    }

    Py_INCREF(pattern);
    self->pattern = (PyObject*) pattern;

    return (PyObject*) self;
}

static void
pattern_dealloc(PatternObject* self)
{
    Py_XDECREF(self->pattern);
    Py_XDECREF(self->groupindex);
    Py_XDECREF(self->indexgroup);
    PyObject_DEL(self);
}

static PyObject*
pattern_match(PatternObject* self, PyObject* args, PyObject* kw)
{
    SRE_STATE state;
    int status;

    PyObject* string;
    int start = 0;
    int end = INT_MAX;
    static const char *const kwlist[] = { "pattern", "pos", "endpos", NULL };
    if (!PyArg_ParseTupleAndKeywords(args, kw, "O|ii:match", kwlist,
                                     &string, &start, &end))
        return NULL;

    string = state_init(&state, self, string, start, end);
    if (!string)
        return NULL;

    state.ptr = state.start;

    TRACE(("|%p|%p|MATCH\n", PatternObject_GetCode(self), state.ptr));

    if (state.charsize == 1) {
        status = sre_match(&state, PatternObject_GetCode(self), 1);
    } else {
#if defined(HAVE_UNICODE)
        status = sre_umatch(&state, PatternObject_GetCode(self), 1);
#endif
    }

    TRACE(("|%p|%p|END\n", PatternObject_GetCode(self), state.ptr));

    state_fini(&state);

    return pattern_new_match(self, &state, status);
}

static PyObject*
pattern_search(PatternObject* self, PyObject* args, PyObject* kw)
{
    SRE_STATE state;
    int status;

    PyObject* string;
    int start = 0;
    int end = INT_MAX;
    static const char *const kwlist[] = { "pattern", "pos", "endpos", NULL };
    if (!PyArg_ParseTupleAndKeywords(args, kw, "O|ii:search", kwlist,
                                     &string, &start, &end))
        return NULL;

    string = state_init(&state, self, string, start, end);
    if (!string)
        return NULL;

    TRACE(("|%p|%p|SEARCH\n", PatternObject_GetCode(self), state.ptr));

    if (state.charsize == 1) {
        status = sre_search(&state, PatternObject_GetCode(self));
    } else {
#if defined(HAVE_UNICODE)
        status = sre_usearch(&state, PatternObject_GetCode(self));
#endif
    }

    TRACE(("|%p|%p|END\n", PatternObject_GetCode(self), state.ptr));

    state_fini(&state);

    return pattern_new_match(self, &state, status);
}

static PyObject*
call(char* module, char* function, PyObject* args)
{
    PyObject* name;
    PyObject* mod;
    PyObject* func;
    PyObject* result;

    if (!args)
        return NULL;
    name = PyString_FromString(module);
    if (!name)
        return NULL;
    mod = PyImport_Import(name);
    Py_DECREF(name);
    if (!mod)
        return NULL;
    func = PyObject_GetAttrString(mod, function);
    Py_DECREF(mod);
    if (!func)
        return NULL;
    result = PyObject_CallObject(func, args);
    Py_DECREF(func);
    Py_DECREF(args);
    return result;
}

#ifdef USE_BUILTIN_COPY
static int
deepcopy(PyObject** object, PyObject* memo)
{
    PyObject* copy;

    copy = call(
        "copy", "deepcopy",
        Py_BuildValue("OO", *object, memo)
        );
    if (!copy)
        return 0;

    Py_DECREF(*object);
    *object = copy;

    return 1; /* success */
}
#endif