/*

Unicode implementation based on original code by Fredrik Lundh,

modified by Marc-Andre Lemburg <mal@lemburg.com> according to the

Unicode Integration Proposal (see file Misc/unicode.txt).

Major speed upgrades to the method implementations at the Reykjavik

NeedForSpeed sprint, by Fredrik Lundh and Andrew Dalke.

Copyright (c) Corporation for National Research Initiatives.

--------------------------------------------------------------------

The original string type implementation is:

    Copyright (c) 1999 by Secret Labs AB

    Copyright (c) 1999 by Fredrik Lundh

By obtaining, using, and/or copying this software and/or its

associated documentation, you agree that you have read, understood,

and will comply with the following terms and conditions:

Permission to use, copy, modify, and distribute this software and its

associated documentation for any purpose and without fee is hereby

granted, provided that the above copyright notice appears in all

copies, and that both that copyright notice and this permission notice

appear in supporting documentation, and that the name of Secret Labs

AB or the author not be used in advertising or publicity pertaining to

distribution of the software without specific, written prior

permission.

SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO

THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR BE LIABLE FOR

ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT

OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

--------------------------------------------------------------------

*/

#define PY_SSIZE_T_CLEAN

#include "Python.h"

#include "unicodeobject.h"

#include "ucnhash.h"

#ifdef MS_WINDOWS

#include <windows.h>

#endif

/* Limit for the Unicode object free list */

#define PyUnicode_MAXFREELIST       1024

/* Limit for the Unicode object free list stay alive optimization.

   The implementation will keep allocated Unicode memory intact for

   all objects on the free list having a size less than this

   limit. This reduces malloc() overhead for small Unicode objects.

   At worst this will result in PyUnicode_MAXFREELIST *

   (sizeof(PyUnicodeObject) + KEEPALIVE_SIZE_LIMIT +

   malloc()-overhead) bytes of unused garbage.

   Setting the limit to 0 effectively turns the feature off.

   Note: This is an experimental feature ! If you get core dumps when

   using Unicode objects, turn this feature off.

*/

#define KEEPALIVE_SIZE_LIMIT       9

/* Endianness switches; defaults to little endian */

#ifdef WORDS_BIGENDIAN

# define BYTEORDER_IS_BIG_ENDIAN

#else

# define BYTEORDER_IS_LITTLE_ENDIAN

#endif

/* --- Globals ------------------------------------------------------------

   The globals are initialized by the _PyUnicode_Init() API and should

   not be used before calling that API.

*/

#ifdef __cplusplus

extern "C" {

#endif

/* Free list for Unicode objects */

static PyUnicodeObject *free_list;

static int numfree;

/* The empty Unicode object is shared to improve performance. */

static PyUnicodeObject *unicode_empty;

/* Single character Unicode strings in the Latin-1 range are being

   shared as well. */

static PyUnicodeObject *unicode_latin1[256];

/* Default encoding to use and assume when NULL is passed as encoding

   parameter; it is initialized by _PyUnicode_Init().

   Always use the PyUnicode_SetDefaultEncoding() and

   PyUnicode_GetDefaultEncoding() APIs to access this global.

*/

static char unicode_default_encoding[100];

/* Fast detection of the most frequent whitespace characters */

const unsigned char _Py_ascii_whitespace[] = {

	0, 0, 0, 0, 0, 0, 0, 0,

/*     case 0x0009: * HORIZONTAL TABULATION */

/*     case 0x000A: * LINE FEED */

/*     case 0x000B: * VERTICAL TABULATION */

/*     case 0x000C: * FORM FEED */

/*     case 0x000D: * CARRIAGE RETURN */

	0, 1, 1, 1, 1, 1, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

/*     case 0x001C: * FILE SEPARATOR */

/*     case 0x001D: * GROUP SEPARATOR */

/*     case 0x001E: * RECORD SEPARATOR */

/*     case 0x001F: * UNIT SEPARATOR */

	0, 0, 0, 0, 1, 1, 1, 1,

/*     case 0x0020: * SPACE */

	1, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0

};

/* Same for linebreaks */

static unsigned char ascii_linebreak[] = {

	0, 0, 0, 0, 0, 0, 0, 0,

/*         0x000A, * LINE FEED */

/*         0x000D, * CARRIAGE RETURN */

	0, 0, 1, 0, 0, 1, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

/*         0x001C, * FILE SEPARATOR */

/*         0x001D, * GROUP SEPARATOR */

/*         0x001E, * RECORD SEPARATOR */

	0, 0, 0, 0, 1, 1, 1, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0,

	0, 0, 0, 0, 0, 0, 0, 0

};

Py_UNICODE

PyUnicode_GetMax(void)

{

#ifdef Py_UNICODE_WIDE

	return 0x10FFFF;

#else

	/* This is actually an illegal character, so it should

	   not be passed to unichr. */

	return 0xFFFF;

#endif

}

/* --- Bloom Filters ----------------------------------------------------- */

/* stuff to implement simple "bloom filters" for Unicode characters.

   to keep things simple, we use a single bitmask, using the least 5

   bits from each unicode characters as the bit index. */

/* the linebreak mask is set up by Unicode_Init below */

#define BLOOM_MASK unsigned long

static BLOOM_MASK bloom_linebreak;

#define BLOOM(mask, ch) ((mask & (1 << ((ch) & 0x1F))))

#define BLOOM_LINEBREAK(ch) \

    ((ch) < 128U ? ascii_linebreak[(ch)] : \

    (BLOOM(bloom_linebreak, (ch)) && Py_UNICODE_ISLINEBREAK(ch)))

Py_LOCAL_INLINE(BLOOM_MASK) make_bloom_mask(Py_UNICODE* ptr, Py_ssize_t len)

{

    /* calculate simple bloom-style bitmask for a given unicode string */

    long mask;

    Py_ssize_t i;

    mask = 0;

    for (i = 0; i < len; i++)

        mask |= (1 << (ptr[i] & 0x1F));

    return mask;

}

Py_LOCAL_INLINE(int) unicode_member(Py_UNICODE chr, Py_UNICODE* set, Py_ssize_t setlen)

{

    Py_ssize_t i;

    for (i = 0; i < setlen; i++)

        if (set[i] == chr)

            return 1;

    return 0;

}

#define BLOOM_MEMBER(mask, chr, set, setlen)\

    BLOOM(mask, chr) && unicode_member(chr, set, setlen)

/* --- Unicode Object ----------------------------------------------------- */

static

int unicode_resize(register PyUnicodeObject *unicode,

                      Py_ssize_t length)

{

    void *oldstr;

    /* Shortcut if there's nothing much to do. */

    if (unicode->length == length)

	goto reset;

    /* Resizing shared object (unicode_empty or single character

       objects) in-place is not allowed. Use PyUnicode_Resize()

       instead ! */

    if (unicode == unicode_empty || 

	(unicode->length == 1 && 

	 unicode->str[0] < 256U &&

	 unicode_latin1[unicode->str[0]] == unicode)) {

        PyErr_SetString(PyExc_SystemError,

                        "can't resize shared unicode objects");

        return -1;

    }

    /* We allocate one more byte to make sure the string is Ux0000 terminated.

       The overallocation is also used by fastsearch, which assumes that it's

       safe to look at str[length] (without making any assumptions about what

       it contains). */

    oldstr = unicode->str;

    unicode->str = PyObject_REALLOC(unicode->str,

				    sizeof(Py_UNICODE) * (length + 1));

    if (!unicode->str) {

	unicode->str = (Py_UNICODE *)oldstr;

        PyErr_NoMemory();

        return -1;

    }

    unicode->str[length] = 0;

    unicode->length = length;

 reset:

    /* Reset the object caches */

    if (unicode->defenc) {

        Py_DECREF(unicode->defenc);

        unicode->defenc = NULL;

    }

    unicode->hash = -1;

    return 0;

}

/* We allocate one more byte to make sure the string is

   Ux0000 terminated -- XXX is this needed ?

   XXX This allocator could further be enhanced by assuring that the

       free list never reduces its size below 1.

*/

static

PyUnicodeObject *_PyUnicode_New(Py_ssize_t length)

{

    register PyUnicodeObject *unicode;

    /* Optimization for empty strings */

    if (length == 0 && unicode_empty != NULL) {

        Py_INCREF(unicode_empty);

        return unicode_empty;

    }

    /* Ensure we won't overflow the size. */

    if (length > ((PY_SSIZE_T_MAX / sizeof(Py_UNICODE)) - 1)) {

        return (PyUnicodeObject *)PyErr_NoMemory();

    }

    /* Unicode freelist & memory allocation */

    if (free_list) {

        unicode = free_list;

        free_list = *(PyUnicodeObject **)unicode;

        numfree--;

	if (unicode->str) {

	    /* Keep-Alive optimization: we only upsize the buffer,

	       never downsize it. */

	    if ((unicode->length < length) &&

                unicode_resize(unicode, length) < 0) {

		PyObject_DEL(unicode->str);

		unicode->str = NULL;

	    }

	}

        else {

	    size_t new_size = sizeof(Py_UNICODE) * ((size_t)length + 1);

	    unicode->str = (Py_UNICODE*) PyObject_MALLOC(new_size);

        }

        PyObject_INIT(unicode, &PyUnicode_Type);

    }

    else {

	size_t new_size;

        unicode = PyObject_New(PyUnicodeObject, &PyUnicode_Type);

        if (unicode == NULL)

            return NULL;

	new_size = sizeof(Py_UNICODE) * ((size_t)length + 1);

	unicode->str = (Py_UNICODE*) PyObject_MALLOC(new_size);

    }

    if (!unicode->str) {

	PyErr_NoMemory();

	goto onError;

    }

    /* Initialize the first element to guard against cases where

     * the caller fails before initializing str -- unicode_resize()

     * reads str[0], and the Keep-Alive optimization can keep memory

     * allocated for str alive across a call to unicode_dealloc(unicode).

     * We don't want unicode_resize to read uninitialized memory in

     * that case.

     */

    unicode->str[0] = 0;

    unicode->str[length] = 0;

    unicode->length = length;

    unicode->hash = -1;

    unicode->defenc = NULL;

    return unicode;

 onError:

    /* XXX UNREF/NEWREF interface should be more symmetrical */

    _Py_DEC_REFTOTAL;

    _Py_ForgetReference((PyObject *)unicode);

    PyObject_Del(unicode);

    return NULL;

}

static

void unicode_dealloc(register PyUnicodeObject *unicode)

{

    if (PyUnicode_CheckExact(unicode) &&

	numfree < PyUnicode_MAXFREELIST) {

        /* Keep-Alive optimization */

	if (unicode->length >= KEEPALIVE_SIZE_LIMIT) {

	    PyObject_DEL(unicode->str);

	    unicode->str = NULL;

	    unicode->length = 0;

	}

	if (unicode->defenc) {

	    Py_DECREF(unicode->defenc);

	    unicode->defenc = NULL;

	}

	/* Add to free list */

        *(PyUnicodeObject **)unicode = free_list;

        free_list = unicode;

        numfree++;

    }

    else {

	PyObject_DEL(unicode->str);

	Py_XDECREF(unicode->defenc);

	Py_TYPE(unicode)->tp_free((PyObject *)unicode);

    }

}

int PyUnicode_Resize(PyObject **unicode, Py_ssize_t length)

{

    register PyUnicodeObject *v;

    /* Argument checks */

    if (unicode == NULL) {

	PyErr_BadInternalCall();

	return -1;

    }

    v = (PyUnicodeObject *)*unicode;

    if (v == NULL || !PyUnicode_Check(v) || Py_REFCNT(v) != 1 || length < 0) {

	PyErr_BadInternalCall();

	return -1;

    }

    /* Resizing unicode_empty and single character objects is not

       possible since these are being shared. We simply return a fresh

       copy with the same Unicode content. */

    if (v->length != length &&

	(v == unicode_empty || v->length == 1)) {

	PyUnicodeObject *w = _PyUnicode_New(length);

	if (w == NULL)

	    return -1;

	Py_UNICODE_COPY(w->str, v->str,

			length < v->length ? length : v->length);

	Py_DECREF(*unicode);

	*unicode = (PyObject *)w;

	return 0;

    }

    /* Note that we don't have to modify *unicode for unshared Unicode

       objects, since we can modify them in-place. */

    return unicode_resize(v, length);

}

/* Internal API for use in unicodeobject.c only ! */

#define _PyUnicode_Resize(unicodevar, length) \

        PyUnicode_Resize(((PyObject **)(unicodevar)), length)

PyObject *PyUnicode_FromUnicode(const Py_UNICODE *u,

				Py_ssize_t size)

{

    PyUnicodeObject *unicode;

    /* If the Unicode data is known at construction time, we can apply

       some optimizations which share commonly used objects. */

    if (u != NULL) {

	/* Optimization for empty strings */

	if (size == 0 && unicode_empty != NULL) {

	    Py_INCREF(unicode_empty);

	    return (PyObject *)unicode_empty;

	}

	/* Single character Unicode objects in the Latin-1 range are

	   shared when using this constructor */

	if (size == 1 && *u < 256) {

	    unicode = unicode_latin1[*u];

	    if (!unicode) {

		unicode = _PyUnicode_New(1);

		if (!unicode)

		    return NULL;

		unicode->str[0] = *u;

		unicode_latin1[*u] = unicode;

	    }

	    Py_INCREF(unicode);

	    return (PyObject *)unicode;

	}

    }

    unicode = _PyUnicode_New(size);

    if (!unicode)

        return NULL;

    /* Copy the Unicode data into the new object */

    if (u != NULL)

	Py_UNICODE_COPY(unicode->str, u, size);

    return (PyObject *)unicode;

}

PyObject *PyUnicode_FromStringAndSize(const char *u, Py_ssize_t size)

{

    PyUnicodeObject *unicode;

	if (size < 0) {

		PyErr_SetString(PyExc_SystemError,

		    "Negative size passed to PyUnicode_FromStringAndSize");

		return NULL;

	}

    /* If the Unicode data is known at construction time, we can apply

       some optimizations which share commonly used objects.

       Also, this means the input must be UTF-8, so fall back to the

       UTF-8 decoder at the end. */

    if (u != NULL) {

	/* Optimization for empty strings */

	if (size == 0 && unicode_empty != NULL) {

	    Py_INCREF(unicode_empty);

	    return (PyObject *)unicode_empty;

	}

	/* Single characters are shared when using this constructor.

           Restrict to ASCII, since the input must be UTF-8. */

	if (size == 1 && Py_CHARMASK(*u) < 128) {

	    unicode = unicode_latin1[Py_CHARMASK(*u)];

	    if (!unicode) {

		unicode = _PyUnicode_New(1);

		if (!unicode)

		    return NULL;

		unicode->str[0] = Py_CHARMASK(*u);

		unicode_latin1[Py_CHARMASK(*u)] = unicode;

	    }

	    Py_INCREF(unicode);

	    return (PyObject *)unicode;

	}

        return PyUnicode_DecodeUTF8(u, size, NULL);

    }

    unicode = _PyUnicode_New(size);

    if (!unicode)

        return NULL;

    return (PyObject *)unicode;

}

PyObject *PyUnicode_FromString(const char *u)

{

    size_t size = strlen(u);

    if (size > PY_SSIZE_T_MAX) {

        PyErr_SetString(PyExc_OverflowError, "input too long");

        return NULL;

    }

    return PyUnicode_FromStringAndSize(u, size);

}

#ifdef HAVE_WCHAR_H