add ydb deps

1 files changed, 2099 insertions, 0 deletions

diff --git a/contrib/tools/python/src/Modules/_struct.c b/contrib/tools/python/src/Modules/_struct.c
new file mode 100644
index 0000000000..8b97672070
--- /dev/null
+++ b/contrib/tools/python/src/Modules/_struct.c
@@ -0,0 +1,2099 @@
+/* struct module -- pack values into and (out of) strings */
+
+/* New version supporting byte order, alignment and size options,
+   character strings, and unsigned numbers */
+
+#define PY_SSIZE_T_CLEAN
+
+#include "Python.h"
+#include "structseq.h"
+#include "structmember.h"
+#include <ctype.h>
+
+static PyTypeObject PyStructType;
+
+/* compatibility macros */
+#if (PY_VERSION_HEX < 0x02050000)
+typedef int Py_ssize_t;
+#endif
+
+/* warning messages */
+#define FLOAT_COERCE_WARN "integer argument expected, got float"
+#define NON_INTEGER_WARN "integer argument expected, got non-integer " \
+    "(implicit conversion using __int__ is deprecated)"
+
+
+/* The translation function for each format character is table driven */
+typedef struct _formatdef {
+    char format;
+    Py_ssize_t size;
+    Py_ssize_t alignment;
+    PyObject* (*unpack)(const char *,
+                        const struct _formatdef *);
+    int (*pack)(char *, PyObject *,
+                const struct _formatdef *);
+} formatdef;
+
+typedef struct _formatcode {
+    const struct _formatdef *fmtdef;
+    Py_ssize_t offset;
+    Py_ssize_t size;
+} formatcode;
+
+/* Struct object interface */
+
+typedef struct {
+    PyObject_HEAD
+    Py_ssize_t s_size;
+    Py_ssize_t s_len;
+    formatcode *s_codes;
+    PyObject *s_format;
+    PyObject *weakreflist; /* List of weak references */
+} PyStructObject;
+
+
+#define PyStruct_Check(op) PyObject_TypeCheck(op, &PyStructType)
+#define PyStruct_CheckExact(op) (Py_TYPE(op) == &PyStructType)
+
+
+/* Exception */
+
+static PyObject *StructError;
+
+
+/* Define various structs to figure out the alignments of types */
+
+
+typedef struct { char c; short x; } st_short;
+typedef struct { char c; int x; } st_int;
+typedef struct { char c; long x; } st_long;
+typedef struct { char c; float x; } st_float;
+typedef struct { char c; double x; } st_double;
+typedef struct { char c; void *x; } st_void_p;
+
+#define SHORT_ALIGN (sizeof(st_short) - sizeof(short))
+#define INT_ALIGN (sizeof(st_int) - sizeof(int))
+#define LONG_ALIGN (sizeof(st_long) - sizeof(long))
+#define FLOAT_ALIGN (sizeof(st_float) - sizeof(float))
+#define DOUBLE_ALIGN (sizeof(st_double) - sizeof(double))
+#define VOID_P_ALIGN (sizeof(st_void_p) - sizeof(void *))
+
+/* We can't support q and Q in native mode unless the compiler does;
+   in std mode, they're 8 bytes on all platforms. */
+#ifdef HAVE_LONG_LONG
+typedef struct { char c; PY_LONG_LONG x; } s_long_long;
+#define LONG_LONG_ALIGN (sizeof(s_long_long) - sizeof(PY_LONG_LONG))
+#endif
+
+#ifdef HAVE_C99_BOOL
+#define BOOL_TYPE _Bool
+typedef struct { char c; _Bool x; } s_bool;
+#define BOOL_ALIGN (sizeof(s_bool) - sizeof(BOOL_TYPE))
+#else
+#define BOOL_TYPE char
+#define BOOL_ALIGN 0
+#endif
+
+#define STRINGIFY(x)    #x
+
+#ifdef __powerc
+#pragma options align=reset
+#endif
+
+static char *integer_codes = "bBhHiIlLqQ";
+
+/* Helper to get a PyLongObject by hook or by crook.  Caller should decref. */
+
+static PyObject *
+get_pylong(PyObject *v)
+{
+    PyObject *r, *w;
+    int converted = 0;
+    assert(v != NULL);
+    if (!_PyAnyInt_Check(v)) {
+        PyNumberMethods *m;
+        /* Not an integer; first try to use __index__ to
+           convert to an integer.  If the __index__ method
+           doesn't exist, or raises a TypeError, try __int__.
+           Use of the latter is deprecated, and will fail in
+           Python 3.x. */
+
+        m = Py_TYPE(v)->tp_as_number;
+        if (PyIndex_Check(v)) {
+            w = PyNumber_Index(v);
+            if (w != NULL) {
+                v = w;
+                /* successfully converted to an integer */
+                converted = 1;
+            }
+            else if (PyErr_ExceptionMatches(PyExc_TypeError)) {
+                PyErr_Clear();
+            }
+            else
+                return NULL;
+        }
+        if (!converted && m != NULL && m->nb_int != NULL) {
+            /* Special case warning message for floats, for
+               backwards compatibility. */
+            if (PyFloat_Check(v)) {
+                if (PyErr_WarnEx(
+                            PyExc_DeprecationWarning,
+                            FLOAT_COERCE_WARN, 1))
+                    return NULL;
+            }
+            else {
+                if (PyErr_WarnEx(
+                            PyExc_DeprecationWarning,
+                            NON_INTEGER_WARN, 1))
+                    return NULL;
+            }
+            v = m->nb_int(v);
+            if (v == NULL)
+                return NULL;
+            if (!_PyAnyInt_Check(v)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "__int__ method returned "
+                                "non-integer");
+                return NULL;
+            }
+            converted = 1;
+        }
+        if (!converted) {
+            PyErr_SetString(StructError,
+                            "cannot convert argument "
+                            "to integer");
+            return NULL;
+        }
+    }
+    else
+        /* Ensure we own a reference to v. */
+        Py_INCREF(v);
+
+    assert(_PyAnyInt_Check(v));
+    if (PyInt_Check(v)) {
+        r = PyLong_FromLong(PyInt_AS_LONG(v));
+        Py_DECREF(v);
+    }
+    else if (PyLong_Check(v)) {
+        assert(PyLong_Check(v));
+        r = v;
+    }
+    else {
+        r = NULL;   /* silence compiler warning about
+                       possibly uninitialized variable */
+        assert(0);  /* shouldn't ever get here */
+    }
+
+    return r;
+}
+
+/* Helper to convert a Python object to a C long.  Sets an exception
+   (struct.error for an inconvertible type, OverflowError for
+   out-of-range values) and returns -1 on error. */
+
+static int
+get_long(PyObject *v, long *p)
+{
+    long x;
+
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    assert(PyLong_Check(v));
+    x = PyLong_AsLong(v);
+    Py_DECREF(v);
+    if (x == (long)-1 && PyErr_Occurred())
+        return -1;
+    *p = x;
+    return 0;
+}
+
+/* Same, but handling unsigned long */
+
+static int
+get_ulong(PyObject *v, unsigned long *p)
+{
+    unsigned long x;
+
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    assert(PyLong_Check(v));
+    x = PyLong_AsUnsignedLong(v);
+    Py_DECREF(v);
+    if (x == (unsigned long)-1 && PyErr_Occurred())
+        return -1;
+    *p = x;
+    return 0;
+}
+
+#ifdef HAVE_LONG_LONG
+
+/* Same, but handling native long long. */
+
+static int
+get_longlong(PyObject *v, PY_LONG_LONG *p)
+{
+    PY_LONG_LONG x;
+
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    assert(PyLong_Check(v));
+    x = PyLong_AsLongLong(v);
+    Py_DECREF(v);
+    if (x == (PY_LONG_LONG)-1 && PyErr_Occurred())
+        return -1;
+    *p = x;
+    return 0;
+}
+
+/* Same, but handling native unsigned long long. */
+
+static int
+get_ulonglong(PyObject *v, unsigned PY_LONG_LONG *p)
+{
+    unsigned PY_LONG_LONG x;
+
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    assert(PyLong_Check(v));
+    x = PyLong_AsUnsignedLongLong(v);
+    Py_DECREF(v);
+    if (x == (unsigned PY_LONG_LONG)-1 && PyErr_Occurred())
+        return -1;
+    *p = x;
+    return 0;
+}
+
+#endif
+
+/* Floating point helpers */
+
+static PyObject *
+unpack_float(const char *p,  /* start of 4-byte string */
+         int le)             /* true for little-endian, false for big-endian */
+{
+    double x;
+
+    x = _PyFloat_Unpack4((unsigned char *)p, le);
+    if (x == -1.0 && PyErr_Occurred())
+        return NULL;
+    return PyFloat_FromDouble(x);
+}
+
+static PyObject *
+unpack_double(const char *p,  /* start of 8-byte string */
+          int le)         /* true for little-endian, false for big-endian */
+{
+    double x;
+
+    x = _PyFloat_Unpack8((unsigned char *)p, le);
+    if (x == -1.0 && PyErr_Occurred())
+        return NULL;
+    return PyFloat_FromDouble(x);
+}
+
+/* Helper to format the range error exceptions */
+static int
+_range_error(const formatdef *f, int is_unsigned)
+{
+    /* ulargest is the largest unsigned value with f->size bytes.
+     * Note that the simpler:
+     *     ((size_t)1 << (f->size * 8)) - 1
+     * doesn't work when f->size == sizeof(size_t) because C doesn't
+     * define what happens when a left shift count is >= the number of
+     * bits in the integer being shifted; e.g., on some boxes it doesn't
+     * shift at all when they're equal.
+     */
+    const size_t ulargest = (size_t)-1 >> ((SIZEOF_SIZE_T - f->size)*8);
+    assert(f->size >= 1 && f->size <= SIZEOF_SIZE_T);
+    if (is_unsigned)
+        PyErr_Format(StructError,
+            "'%c' format requires 0 <= number <= %zu",
+            f->format,
+            ulargest);
+    else {
+        const Py_ssize_t largest = (Py_ssize_t)(ulargest >> 1);
+        PyErr_Format(StructError,
+            "'%c' format requires %zd <= number <= %zd",
+            f->format,
+            ~ largest,
+            largest);
+    }
+    return -1;
+}
+
+
+
+/* A large number of small routines follow, with names of the form
+
+   [bln][up]_TYPE
+
+   [bln] distiguishes among big-endian, little-endian and native.
+   [pu] distiguishes between pack (to struct) and unpack (from struct).
+   TYPE is one of char, byte, ubyte, etc.
+*/
+
+/* Native mode routines. ****************************************************/
+/* NOTE:
+   In all n[up]_<type> routines handling types larger than 1 byte, there is
+   *no* guarantee that the p pointer is properly aligned for each type,
+   therefore memcpy is called.  An intermediate variable is used to
+   compensate for big-endian architectures.
+   Normally both the intermediate variable and the memcpy call will be
+   skipped by C optimisation in little-endian architectures (gcc >= 2.91
+   does this). */
+
+static PyObject *
+nu_char(const char *p, const formatdef *f)
+{
+    return PyString_FromStringAndSize(p, 1);
+}
+
+static PyObject *
+nu_byte(const char *p, const formatdef *f)
+{
+    return PyInt_FromLong((long) *(signed char *)p);
+}
+
+static PyObject *
+nu_ubyte(const char *p, const formatdef *f)
+{
+    return PyInt_FromLong((long) *(unsigned char *)p);
+}
+
+static PyObject *
+nu_short(const char *p, const formatdef *f)
+{
+    short x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyInt_FromLong((long)x);
+}
+
+static PyObject *
+nu_ushort(const char *p, const formatdef *f)
+{
+    unsigned short x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyInt_FromLong((long)x);
+}
+
+static PyObject *
+nu_int(const char *p, const formatdef *f)
+{
+    int x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyInt_FromLong((long)x);
+}
+
+static PyObject *
+nu_uint(const char *p, const formatdef *f)
+{
+    unsigned int x;
+    memcpy((char *)&x, p, sizeof x);
+#if (SIZEOF_LONG > SIZEOF_INT)
+    return PyInt_FromLong((long)x);
+#else
+    if (x <= ((unsigned int)LONG_MAX))
+        return PyInt_FromLong((long)x);
+    return PyLong_FromUnsignedLong((unsigned long)x);
+#endif
+}
+
+static PyObject *
+nu_long(const char *p, const formatdef *f)
+{
+    long x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyInt_FromLong(x);
+}
+
+static PyObject *
+nu_ulong(const char *p, const formatdef *f)
+{
+    unsigned long x;
+    memcpy((char *)&x, p, sizeof x);
+    if (x <= LONG_MAX)
+        return PyInt_FromLong((long)x);
+    return PyLong_FromUnsignedLong(x);
+}
+
+/* Native mode doesn't support q or Q unless the platform C supports
+   long long (or, on Windows, __int64). */
+
+#ifdef HAVE_LONG_LONG
+
+static PyObject *
+nu_longlong(const char *p, const formatdef *f)
+{
+    PY_LONG_LONG x;
+    memcpy((char *)&x, p, sizeof x);
+    if (x >= LONG_MIN && x <= LONG_MAX)
+        return PyInt_FromLong(Py_SAFE_DOWNCAST(x, PY_LONG_LONG, long));
+    return PyLong_FromLongLong(x);
+}
+
+static PyObject *
+nu_ulonglong(const char *p, const formatdef *f)
+{
+    unsigned PY_LONG_LONG x;
+    memcpy((char *)&x, p, sizeof x);
+    if (x <= LONG_MAX)
+        return PyInt_FromLong(Py_SAFE_DOWNCAST(x, unsigned PY_LONG_LONG, long));
+    return PyLong_FromUnsignedLongLong(x);
+}
+
+#endif
+
+static PyObject *
+nu_bool(const char *p, const formatdef *f)
+{
+    BOOL_TYPE x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyBool_FromLong(x != 0);
+}
+
+
+static PyObject *
+nu_float(const char *p, const formatdef *f)
+{
+    float x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyFloat_FromDouble((double)x);
+}
+
+static PyObject *
+nu_double(const char *p, const formatdef *f)
+{
+    double x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyFloat_FromDouble(x);
+}
+
+static PyObject *
+nu_void_p(const char *p, const formatdef *f)
+{
+    void *x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyLong_FromVoidPtr(x);
+}
+
+static int
+np_byte(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    if (get_long(v, &x) < 0)
+        return -1;
+    if (x < -128 || x > 127){
+        PyErr_SetString(StructError,
+                        "byte format requires -128 <= number <= 127");
+        return -1;
+    }
+    *p = (char)x;
+    return 0;
+}
+
+static int
+np_ubyte(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    if (get_long(v, &x) < 0)
+        return -1;
+    if (x < 0 || x > 255){
+        PyErr_SetString(StructError,
+                        "ubyte format requires 0 <= number <= 255");
+        return -1;
+    }
+    *(unsigned char *)p = (unsigned char)x;
+    return 0;
+}
+
+static int
+np_char(char *p, PyObject *v, const formatdef *f)
+{
+    if (!PyString_Check(v) || PyString_Size(v) != 1) {
+        PyErr_SetString(StructError,
+                        "char format require string of length 1");
+        return -1;
+    }
+    *p = *PyString_AsString(v);
+    return 0;
+}
+
+static int
+np_short(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    short y;
+    if (get_long(v, &x) < 0)
+        return -1;
+    if (x < SHRT_MIN || x > SHRT_MAX){
+        PyErr_SetString(StructError,
+                        "short format requires " STRINGIFY(SHRT_MIN)
+                        " <= number <= " STRINGIFY(SHRT_MAX));
+        return -1;
+    }
+    y = (short)x;
+    memcpy(p, (char *)&y, sizeof y);
+    return 0;
+}
+
+static int
+np_ushort(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    unsigned short y;
+    if (get_long(v, &x) < 0)
+        return -1;
+    if (x < 0 || x > USHRT_MAX){
+        PyErr_SetString(StructError,
+                        "ushort format requires 0 <= number <= " STRINGIFY(USHRT_MAX));
+        return -1;
+    }
+    y = (unsigned short)x;
+    memcpy(p, (char *)&y, sizeof y);
+    return 0;
+}
+
+static int
+np_int(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    int y;
+    if (get_long(v, &x) < 0)
+        return -1;
+#if (SIZEOF_LONG > SIZEOF_INT)
+    if ((x < ((long)INT_MIN)) || (x > ((long)INT_MAX)))
+        return _range_error(f, 0);
+#endif
+    y = (int)x;
+    memcpy(p, (char *)&y, sizeof y);
+    return 0;
+}
+
+static int
+np_uint(char *p, PyObject *v, const formatdef *f)
+{
+    unsigned long x;
+    unsigned int y;
+    if (get_ulong(v, &x) < 0)
+        return -1;
+    y = (unsigned int)x;
+#if (SIZEOF_LONG > SIZEOF_INT)
+    if (x > ((unsigned long)UINT_MAX))
+        return _range_error(f, 1);
+#endif
+    memcpy(p, (char *)&y, sizeof y);
+    return 0;
+}
+
+static int
+np_long(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    if (get_long(v, &x) < 0)
+        return -1;
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+
+static int
+np_ulong(char *p, PyObject *v, const formatdef *f)
+{
+    unsigned long x;
+    if (get_ulong(v, &x) < 0)
+        return -1;
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+
+#ifdef HAVE_LONG_LONG
+
+static int
+np_longlong(char *p, PyObject *v, const formatdef *f)
+{
+    PY_LONG_LONG x;
+    if (get_longlong(v, &x) < 0)
+        return -1;
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+
+static int
+np_ulonglong(char *p, PyObject *v, const formatdef *f)
+{
+    unsigned PY_LONG_LONG x;
+    if (get_ulonglong(v, &x) < 0)
+        return -1;
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+#endif
+
+
+static int
+np_bool(char *p, PyObject *v, const formatdef *f)
+{
+    int y;
+    BOOL_TYPE x;
+    y = PyObject_IsTrue(v);
+    if (y < 0)
+        return -1;
+    x = y;
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+
+static int
+np_float(char *p, PyObject *v, const formatdef *f)
+{
+    float x = (float)PyFloat_AsDouble(v);
+    if (x == -1 && PyErr_Occurred()) {
+        PyErr_SetString(StructError,
+                        "required argument is not a float");
+        return -1;
+    }
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+
+static int
+np_double(char *p, PyObject *v, const formatdef *f)
+{
+    double x = PyFloat_AsDouble(v);
+    if (x == -1 && PyErr_Occurred()) {
+        PyErr_SetString(StructError,
+                        "required argument is not a float");
+        return -1;
+    }
+    memcpy(p, (char *)&x, sizeof(double));
+    return 0;
+}
+
+static int
+np_void_p(char *p, PyObject *v, const formatdef *f)
+{
+    void *x;
+
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    assert(PyLong_Check(v));
+    x = PyLong_AsVoidPtr(v);
+    Py_DECREF(v);
+    if (x == NULL && PyErr_Occurred())
+        return -1;
+    memcpy(p, (char *)&x, sizeof x);
+    return 0;
+}
+
+static formatdef native_table[] = {
+    {'x',       sizeof(char),   0,              NULL},
+    {'b',       sizeof(char),   0,              nu_byte,        np_byte},
+    {'B',       sizeof(char),   0,              nu_ubyte,       np_ubyte},
+    {'c',       sizeof(char),   0,              nu_char,        np_char},
+    {'s',       sizeof(char),   0,              NULL},
+    {'p',       sizeof(char),   0,              NULL},
+    {'h',       sizeof(short),  SHORT_ALIGN,    nu_short,       np_short},
+    {'H',       sizeof(short),  SHORT_ALIGN,    nu_ushort,      np_ushort},
+    {'i',       sizeof(int),    INT_ALIGN,      nu_int,         np_int},
+    {'I',       sizeof(int),    INT_ALIGN,      nu_uint,        np_uint},
+    {'l',       sizeof(long),   LONG_ALIGN,     nu_long,        np_long},
+    {'L',       sizeof(long),   LONG_ALIGN,     nu_ulong,       np_ulong},
+#ifdef HAVE_LONG_LONG
+    {'q',       sizeof(PY_LONG_LONG), LONG_LONG_ALIGN, nu_longlong, np_longlong},
+    {'Q',       sizeof(PY_LONG_LONG), LONG_LONG_ALIGN, nu_ulonglong,np_ulonglong},
+#endif
+    {'?',       sizeof(BOOL_TYPE),      BOOL_ALIGN,     nu_bool,        np_bool},
+    {'f',       sizeof(float),  FLOAT_ALIGN,    nu_float,       np_float},
+    {'d',       sizeof(double), DOUBLE_ALIGN,   nu_double,      np_double},
+    {'P',       sizeof(void *), VOID_P_ALIGN,   nu_void_p,      np_void_p},
+    {0}
+};
+
+/* Big-endian routines. *****************************************************/
+
+static PyObject *
+bu_int(const char *p, const formatdef *f)
+{
+    long x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | *bytes++;
+    } while (--i > 0);
+    /* Extend the sign bit. */
+    if (SIZEOF_LONG > f->size)
+        x |= -(x & (1L << ((8 * f->size) - 1)));
+    return PyInt_FromLong(x);
+}
+
+static PyObject *
+bu_uint(const char *p, const formatdef *f)
+{
+    unsigned long x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | *bytes++;
+    } while (--i > 0);
+    if (x <= LONG_MAX)
+        return PyInt_FromLong((long)x);
+    return PyLong_FromUnsignedLong(x);
+}
+
+static PyObject *
+bu_longlong(const char *p, const formatdef *f)
+{
+#ifdef HAVE_LONG_LONG
+    PY_LONG_LONG x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | *bytes++;
+    } while (--i > 0);
+    /* Extend the sign bit. */
+    if (SIZEOF_LONG_LONG > f->size)
+        x |= -(x & ((PY_LONG_LONG)1 << ((8 * f->size) - 1)));
+    if (x >= LONG_MIN && x <= LONG_MAX)
+        return PyInt_FromLong(Py_SAFE_DOWNCAST(x, PY_LONG_LONG, long));
+    return PyLong_FromLongLong(x);
+#else
+    return _PyLong_FromByteArray((const unsigned char *)p,
+                                  8,
+                                  0, /* little-endian */
+                      1  /* signed */);
+#endif
+}
+
+static PyObject *
+bu_ulonglong(const char *p, const formatdef *f)
+{
+#ifdef HAVE_LONG_LONG
+    unsigned PY_LONG_LONG x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | *bytes++;
+    } while (--i > 0);
+    if (x <= LONG_MAX)
+        return PyInt_FromLong(Py_SAFE_DOWNCAST(x, unsigned PY_LONG_LONG, long));
+    return PyLong_FromUnsignedLongLong(x);
+#else
+    return _PyLong_FromByteArray((const unsigned char *)p,
+                                  8,
+                                  0, /* little-endian */
+                      0  /* signed */);
+#endif
+}
+
+static PyObject *
+bu_float(const char *p, const formatdef *f)
+{
+    return unpack_float(p, 0);
+}
+
+static PyObject *
+bu_double(const char *p, const formatdef *f)
+{
+    return unpack_double(p, 0);
+}
+
+static PyObject *
+bu_bool(const char *p, const formatdef *f)
+{
+    char x;
+    memcpy((char *)&x, p, sizeof x);
+    return PyBool_FromLong(x != 0);
+}
+
+static int
+bp_int(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    Py_ssize_t i;
+    unsigned char *q = (unsigned char *)p;
+    if (get_long(v, &x) < 0)
+        return -1;
+    i = f->size;
+    if (i != SIZEOF_LONG) {
+        if ((i == 2) && (x < -32768 || x > 32767))
+            return _range_error(f, 0);
+#if (SIZEOF_LONG != 4)
+        else if ((i == 4) && (x < -2147483648L || x > 2147483647L))
+            return _range_error(f, 0);
+#endif
+    }
+    do {
+        q[--i] = (unsigned char)(x & 0xffL);
+        x >>= 8;
+    } while (i > 0);
+    return 0;
+}
+
+static int
+bp_uint(char *p, PyObject *v, const formatdef *f)
+{
+    unsigned long x;
+    Py_ssize_t i;
+    unsigned char *q = (unsigned char *)p;
+    if (get_ulong(v, &x) < 0)
+        return -1;
+    i = f->size;
+    if (i != SIZEOF_LONG) {
+        unsigned long maxint = 1;
+        maxint <<= (unsigned long)(i * 8);
+        if (x >= maxint)
+            return _range_error(f, 1);
+    }
+    do {
+        q[--i] = (unsigned char)(x & 0xffUL);
+        x >>= 8;
+    } while (i > 0);
+    return 0;
+}
+
+static int
+bp_longlong(char *p, PyObject *v, const formatdef *f)
+{
+    int res;
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    res = _PyLong_AsByteArray((PyLongObject *)v,
+                              (unsigned char *)p,
+                              8,
+                              0, /* little_endian */
+                  1  /* signed */);
+    Py_DECREF(v);
+    return res;
+}
+
+static int
+bp_ulonglong(char *p, PyObject *v, const formatdef *f)
+{
+    int res;
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    res = _PyLong_AsByteArray((PyLongObject *)v,
+                              (unsigned char *)p,
+                              8,
+                              0, /* little_endian */
+                  0  /* signed */);
+    Py_DECREF(v);
+    return res;
+}
+
+static int
+bp_float(char *p, PyObject *v, const formatdef *f)
+{
+    double x = PyFloat_AsDouble(v);
+    if (x == -1 && PyErr_Occurred()) {
+        PyErr_SetString(StructError,
+                        "required argument is not a float");
+        return -1;
+    }
+    return _PyFloat_Pack4(x, (unsigned char *)p, 0);
+}
+
+static int
+bp_double(char *p, PyObject *v, const formatdef *f)
+{
+    double x = PyFloat_AsDouble(v);
+    if (x == -1 && PyErr_Occurred()) {
+        PyErr_SetString(StructError,
+                        "required argument is not a float");
+        return -1;
+    }
+    return _PyFloat_Pack8(x, (unsigned char *)p, 0);
+}
+
+static int
+bp_bool(char *p, PyObject *v, const formatdef *f)
+{
+    int y;
+    y = PyObject_IsTrue(v);
+    if (y < 0)
+        return -1;
+    *p = (char)y;
+    return 0;
+}
+
+static formatdef bigendian_table[] = {
+    {'x',       1,              0,              NULL},
+    {'b',       1,              0,              nu_byte,        np_byte},
+    {'B',       1,              0,              nu_ubyte,       np_ubyte},
+    {'c',       1,              0,              nu_char,        np_char},
+    {'s',       1,              0,              NULL},
+    {'p',       1,              0,              NULL},
+    {'h',       2,              0,              bu_int,         bp_int},
+    {'H',       2,              0,              bu_uint,        bp_uint},
+    {'i',       4,              0,              bu_int,         bp_int},
+    {'I',       4,              0,              bu_uint,        bp_uint},
+    {'l',       4,              0,              bu_int,         bp_int},
+    {'L',       4,              0,              bu_uint,        bp_uint},
+    {'q',       8,              0,              bu_longlong,    bp_longlong},
+    {'Q',       8,              0,              bu_ulonglong,   bp_ulonglong},
+    {'?',       1,              0,              bu_bool,        bp_bool},
+    {'f',       4,              0,              bu_float,       bp_float},
+    {'d',       8,              0,              bu_double,      bp_double},
+    {0}
+};
+
+/* Little-endian routines. *****************************************************/
+
+static PyObject *
+lu_int(const char *p, const formatdef *f)
+{
+    long x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | bytes[--i];
+    } while (i > 0);
+    /* Extend the sign bit. */
+    if (SIZEOF_LONG > f->size)
+        x |= -(x & (1L << ((8 * f->size) - 1)));
+    return PyInt_FromLong(x);
+}
+
+static PyObject *
+lu_uint(const char *p, const formatdef *f)
+{
+    unsigned long x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | bytes[--i];
+    } while (i > 0);
+    if (x <= LONG_MAX)
+        return PyInt_FromLong((long)x);
+    return PyLong_FromUnsignedLong((long)x);
+}
+
+static PyObject *
+lu_longlong(const char *p, const formatdef *f)
+{
+#ifdef HAVE_LONG_LONG
+    PY_LONG_LONG x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | bytes[--i];
+    } while (i > 0);
+    /* Extend the sign bit. */
+    if (SIZEOF_LONG_LONG > f->size)
+        x |= -(x & ((PY_LONG_LONG)1 << ((8 * f->size) - 1)));
+    if (x >= LONG_MIN && x <= LONG_MAX)
+        return PyInt_FromLong(Py_SAFE_DOWNCAST(x, PY_LONG_LONG, long));
+    return PyLong_FromLongLong(x);
+#else
+    return _PyLong_FromByteArray((const unsigned char *)p,
+                                  8,
+                                  1, /* little-endian */
+                      1  /* signed */);
+#endif
+}
+
+static PyObject *
+lu_ulonglong(const char *p, const formatdef *f)
+{
+#ifdef HAVE_LONG_LONG
+    unsigned PY_LONG_LONG x = 0;
+    Py_ssize_t i = f->size;
+    const unsigned char *bytes = (const unsigned char *)p;
+    do {
+        x = (x<<8) | bytes[--i];
+    } while (i > 0);
+    if (x <= LONG_MAX)
+        return PyInt_FromLong(Py_SAFE_DOWNCAST(x, unsigned PY_LONG_LONG, long));
+    return PyLong_FromUnsignedLongLong(x);
+#else
+    return _PyLong_FromByteArray((const unsigned char *)p,
+                                  8,
+                                  1, /* little-endian */
+                      0  /* signed */);
+#endif
+}
+
+static PyObject *
+lu_float(const char *p, const formatdef *f)
+{
+    return unpack_float(p, 1);
+}
+
+static PyObject *
+lu_double(const char *p, const formatdef *f)
+{
+    return unpack_double(p, 1);
+}
+
+static int
+lp_int(char *p, PyObject *v, const formatdef *f)
+{
+    long x;
+    Py_ssize_t i;
+    unsigned char *q = (unsigned char *)p;
+    if (get_long(v, &x) < 0)
+        return -1;
+    i = f->size;
+    if (i != SIZEOF_LONG) {
+        if ((i == 2) && (x < -32768 || x > 32767))
+            return _range_error(f, 0);
+#if (SIZEOF_LONG != 4)
+        else if ((i == 4) && (x < -2147483648L || x > 2147483647L))
+            return _range_error(f, 0);
+#endif
+    }
+    do {
+        *q++ = (unsigned char)(x & 0xffL);
+        x >>= 8;
+    } while (--i > 0);
+    return 0;
+}
+
+static int
+lp_uint(char *p, PyObject *v, const formatdef *f)
+{
+    unsigned long x;
+    Py_ssize_t i;
+    unsigned char *q = (unsigned char *)p;
+    if (get_ulong(v, &x) < 0)
+        return -1;
+    i = f->size;
+    if (i != SIZEOF_LONG) {
+        unsigned long maxint = 1;
+        maxint <<= (unsigned long)(i * 8);
+        if (x >= maxint)
+            return _range_error(f, 1);
+    }
+    do {
+        *q++ = (unsigned char)(x & 0xffUL);
+        x >>= 8;
+    } while (--i > 0);
+    return 0;
+}
+
+static int
+lp_longlong(char *p, PyObject *v, const formatdef *f)
+{
+    int res;
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    res = _PyLong_AsByteArray((PyLongObject*)v,
+                              (unsigned char *)p,
+                              8,
+                              1, /* little_endian */
+                  1  /* signed */);
+    Py_DECREF(v);
+    return res;
+}
+
+static int
+lp_ulonglong(char *p, PyObject *v, const formatdef *f)
+{
+    int res;
+    v = get_pylong(v);
+    if (v == NULL)
+        return -1;
+    res = _PyLong_AsByteArray((PyLongObject*)v,
+                              (unsigned char *)p,
+                              8,
+                              1, /* little_endian */
+                  0  /* signed */);
+    Py_DECREF(v);
+    return res;
+}
+
+static int
+lp_float(char *p, PyObject *v, const formatdef *f)
+{
+    double x = PyFloat_AsDouble(v);
+    if (x == -1 && PyErr_Occurred()) {
+        PyErr_SetString(StructError,
+                        "required argument is not a float");
+        return -1;
+    }
+    return _PyFloat_Pack4(x, (unsigned char *)p, 1);
+}
+
+static int
+lp_double(char *p, PyObject *v, const formatdef *f)
+{
+    double x = PyFloat_AsDouble(v);
+    if (x == -1 && PyErr_Occurred()) {
+        PyErr_SetString(StructError,
+                        "required argument is not a float");
+        return -1;
+    }
+    return _PyFloat_Pack8(x, (unsigned char *)p, 1);
+}
+
+static formatdef lilendian_table[] = {
+    {'x',       1,              0,              NULL},
+    {'b',       1,              0,              nu_byte,        np_byte},
+    {'B',       1,              0,              nu_ubyte,       np_ubyte},
+    {'c',       1,              0,              nu_char,        np_char},
+    {'s',       1,              0,              NULL},
+    {'p',       1,              0,              NULL},
+    {'h',       2,              0,              lu_int,         lp_int},
+    {'H',       2,              0,              lu_uint,        lp_uint},
+    {'i',       4,              0,              lu_int,         lp_int},
+    {'I',       4,              0,              lu_uint,        lp_uint},
+    {'l',       4,              0,              lu_int,         lp_int},
+    {'L',       4,              0,              lu_uint,        lp_uint},
+    {'q',       8,              0,              lu_longlong,    lp_longlong},
+    {'Q',       8,              0,              lu_ulonglong,   lp_ulonglong},
+    {'?',       1,              0,              bu_bool,        bp_bool}, /* Std rep not endian dep,
+        but potentially different from native rep -- reuse bx_bool funcs. */
+    {'f',       4,              0,              lu_float,       lp_float},
+    {'d',       8,              0,              lu_double,      lp_double},
+    {0}
+};
+
+
+static const formatdef *
+whichtable(char **pfmt)
+{
+    const char *fmt = (*pfmt)++; /* May be backed out of later */
+    switch (*fmt) {
+    case '<':
+        return lilendian_table;
+    case '>':
+    case '!': /* Network byte order is big-endian */
+        return bigendian_table;
+    case '=': { /* Host byte order -- different from native in alignment! */
+        int n = 1;
+        char *p = (char *) &n;
+        if (*p == 1)
+            return lilendian_table;
+        else
+            return bigendian_table;
+    }
+    default:
+        --*pfmt; /* Back out of pointer increment */
+        /* Fall through */
+    case '@':
+        return native_table;
+    }
+}
+
+
+/* Get the table entry for a format code */
+
+static const formatdef *
+getentry(int c, const formatdef *f)
+{
+    for (; f->format != '\0'; f++) {
+        if (f->format == c) {
+            return f;
+        }
+    }
+    PyErr_SetString(StructError, "bad char in struct format");
+    return NULL;
+}
+
+
+/* Align a size according to a format code.  Return -1 on overflow. */
+
+static Py_ssize_t
+align(Py_ssize_t size, char c, const formatdef *e)
+{
+    Py_ssize_t extra;
+
+    if (e->format == c) {
+        if (e->alignment && size > 0) {
+            extra = (e->alignment - 1) - (size - 1) % (e->alignment);
+            if (extra > PY_SSIZE_T_MAX - size)
+                return -1;
+            size += extra;
+        }
+    }
+    return size;
+}
+
+
+/* calculate the size of a format string */
+
+static int
+prepare_s(PyStructObject *self)
+{
+    const formatdef *f;
+    const formatdef *e;
+    formatcode *codes;
+
+    const char *s;
+    const char *fmt;
+    char c;
+    Py_ssize_t size, len, num, itemsize;
+
+    fmt = PyString_AS_STRING(self->s_format);
+
+    f = whichtable((char **)&fmt);
+
+    s = fmt;
+    size = 0;
+    len = 0;
+    while ((c = *s++) != '\0') {
+        if (isspace(Py_CHARMASK(c)))
+            continue;
+        if ('0' <= c && c <= '9') {
+            num = c - '0';
+            while ('0' <= (c = *s++) && c <= '9') {
+                /* overflow-safe version of
+                   if (num*10 + (c - '0') > PY_SSIZE_T_MAX) { ... } */
+                if (num >= PY_SSIZE_T_MAX / 10 && (
+                        num > PY_SSIZE_T_MAX / 10 ||
+                        (c - '0') > PY_SSIZE_T_MAX % 10))
+                    goto overflow;
+                num = num*10 + (c - '0');
+            }
+            if (c == '\0')
+                break;
+        }
+        else
+            num = 1;
+
+        e = getentry(c, f);
+        if (e == NULL)
+            return -1;
+
+        switch (c) {
+            case 's': /* fall through */
+            case 'p': len++; break;
+            case 'x': break;
+            default: len += num; break;
+        }
+
+        itemsize = e->size;
+        size = align(size, c, e);
+        if (size == -1)
+            goto overflow;
+
+        /* if (size + num * itemsize > PY_SSIZE_T_MAX) { ... } */
+        if (num > (PY_SSIZE_T_MAX - size) / itemsize)
+            goto overflow;
+        size += num * itemsize;
+    }
+
+    /* check for overflow */
+    if ((len + 1) > (PY_SSIZE_T_MAX / sizeof(formatcode))) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+    self->s_size = size;
+    self->s_len = len;
+    codes = PyMem_MALLOC((len + 1) * sizeof(formatcode));
+    if (codes == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+    /* Free any s_codes value left over from a previous initialization. */
+    if (self->s_codes != NULL)
+        PyMem_FREE(self->s_codes);
+    self->s_codes = codes;
+
+    s = fmt;
+    size = 0;
+    while ((c = *s++) != '\0') {
+        if (isspace(Py_CHARMASK(c)))
+            continue;
+        if ('0' <= c && c <= '9') {
+            num = c - '0';
+            while ('0' <= (c = *s++) && c <= '9')
+                num = num*10 + (c - '0');
+            if (c == '\0')
+                break;
+        }
+        else
+            num = 1;
+
+        e = getentry(c, f);
+
+        size = align(size, c, e);
+        if (c == 's' || c == 'p') {
+            codes->offset = size;
+            codes->size = num;
+            codes->fmtdef = e;
+            codes++;
+            size += num;
+        } else if (c == 'x') {
+            size += num;
+        } else {
+            while (--num >= 0) {
+                codes->offset = size;
+                codes->size = e->size;
+                codes->fmtdef = e;
+                codes++;
+                size += e->size;
+            }
+        }
+    }
+    codes->fmtdef = NULL;
+    codes->offset = size;
+    codes->size = 0;
+
+    return 0;
+
+  overflow:
+    PyErr_SetString(StructError,
+                    "total struct size too long");
+    return -1;
+}
+
+static PyObject *
+s_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+    PyObject *self;
+
+    assert(type != NULL && type->tp_alloc != NULL);
+
+    self = type->tp_alloc(type, 0);
+    if (self != NULL) {
+        PyStructObject *s = (PyStructObject*)self;
+        Py_INCREF(Py_None);
+        s->s_format = Py_None;
+        s->s_codes = NULL;
+        s->s_size = -1;
+        s->s_len = -1;
+    }
+    return self;
+}
+
+static int
+s_init(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    PyStructObject *soself = (PyStructObject *)self;
+    PyObject *o_format = NULL;
+    int ret = 0;
+    static char *kwlist[] = {"format", 0};
+
+    assert(PyStruct_Check(self));
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:Struct", kwlist,
+                                     &o_format))
+        return -1;
+
+    if (PyString_Check(o_format)) {
+        Py_INCREF(o_format);
+        Py_XSETREF(soself->s_format, o_format);
+    }
+    else if (PyUnicode_Check(o_format)) {
+        PyObject *str = PyUnicode_AsEncodedString(o_format, "ascii", NULL);
+        if (str == NULL)
+            return -1;
+        Py_XSETREF(soself->s_format, str);
+    }
+    else {
+        PyErr_Format(PyExc_TypeError,
+                     "Struct() argument 1 must be string, not %s",
+                     Py_TYPE(o_format)->tp_name);
+        return -1;
+    }
+
+    ret = prepare_s(soself);
+    return ret;
+}
+
+static void
+s_dealloc(PyStructObject *s)
+{
+    if (s->weakreflist != NULL)
+        PyObject_ClearWeakRefs((PyObject *)s);
+    if (s->s_codes != NULL) {
+        PyMem_FREE(s->s_codes);
+    }
+    Py_XDECREF(s->s_format);
+    Py_TYPE(s)->tp_free((PyObject *)s);
+}
+
+static PyObject *
+s_unpack_internal(PyStructObject *soself, char *startfrom) {
+    formatcode *code;
+    Py_ssize_t i = 0;
+    PyObject *result = PyTuple_New(soself->s_len);
+    if (result == NULL)
+        return NULL;
+
+    for (code = soself->s_codes; code->fmtdef != NULL; code++) {
+        PyObject *v;
+        const formatdef *e = code->fmtdef;
+        const char *res = startfrom + code->offset;
+        if (e->format == 's') {
+            v = PyString_FromStringAndSize(res, code->size);
+        } else if (e->format == 'p') {
+            Py_ssize_t n = *(unsigned char*)res;
+            if (n >= code->size)
+                n = code->size - 1;
+            v = PyString_FromStringAndSize(res + 1, n);
+        } else {
+            v = e->unpack(res, e);
+        }
+        if (v == NULL)
+            goto fail;
+        PyTuple_SET_ITEM(result, i++, v);
+    }
+
+    return result;
+fail:
+    Py_DECREF(result);
+    return NULL;
+}
+
+
+PyDoc_STRVAR(s_unpack__doc__,
+"S.unpack(str) -> (v1, v2, ...)\n\
+\n\
+Return tuple containing values unpacked according to this Struct's format.\n\
+Requires len(str) == self.size. See struct.__doc__ for more on format\n\
+strings.");
+
+static PyObject *
+s_unpack(PyObject *self, PyObject *inputstr)
+{
+    Py_buffer buf;
+    char *start;
+    Py_ssize_t len;
+    PyObject *args=NULL, *result;
+    PyStructObject *soself = (PyStructObject *)self;
+    assert(PyStruct_Check(self));
+    assert(soself->s_codes != NULL);
+    if (inputstr == NULL)
+        goto fail;
+    if (PyString_Check(inputstr) &&
+        PyString_GET_SIZE(inputstr) == soself->s_size) {
+            return s_unpack_internal(soself, PyString_AS_STRING(inputstr));
+    }
+    args = PyTuple_Pack(1, inputstr);
+    if (args == NULL)
+        return NULL;
+    if (!PyArg_ParseTuple(args, "s*:unpack", &buf))
+        goto fail;
+    start = buf.buf;
+    len = buf.len;
+    if (soself->s_size != len) {
+        PyBuffer_Release(&buf);
+        goto fail;
+    }
+    result = s_unpack_internal(soself, start);
+    Py_DECREF(args);
+    PyBuffer_Release(&buf);
+    return result;
+
+fail:
+    Py_XDECREF(args);
+    PyErr_Format(StructError,
+        "unpack requires a string argument of length %zd",
+        soself->s_size);
+    return NULL;
+}
+
+PyDoc_STRVAR(s_unpack_from__doc__,
+"S.unpack_from(buffer[, offset]) -> (v1, v2, ...)\n\
+\n\
+Return tuple containing values unpacked according to this Struct's format.\n\
+Unlike unpack, unpack_from can unpack values from any object supporting\n\
+the buffer API, not just str. Requires len(buffer[offset:]) >= self.size.\n\
+See struct.__doc__ for more on format strings.");
+
+static PyObject *
+s_unpack_from(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    static char *kwlist[] = {"buffer", "offset", 0};
+    static char *fmt = "z*|n:unpack_from";
+    Py_buffer buf;
+    Py_ssize_t buffer_len = 0, offset = 0;
+    char *buffer = NULL;
+    PyStructObject *soself = (PyStructObject *)self;
+    PyObject *result;
+    assert(PyStruct_Check(self));
+    assert(soself->s_codes != NULL);
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, fmt, kwlist,
+                                     &buf, &offset))
+        return NULL;
+    buffer = buf.buf;
+    buffer_len = buf.len;
+    if (buffer == NULL) {
+        PyErr_Format(StructError,
+            "unpack_from requires a buffer argument");
+        PyBuffer_Release(&buf);
+        return NULL;
+    }
+
+    if (offset < 0)
+        offset += buffer_len;
+
+    if (offset < 0 || (buffer_len - offset) < soself->s_size) {
+        PyErr_Format(StructError,
+            "unpack_from requires a buffer of at least %zd bytes",
+            soself->s_size);
+        PyBuffer_Release(&buf);
+        return NULL;
+    }
+    result = s_unpack_internal(soself, buffer + offset);
+    PyBuffer_Release(&buf);
+    return result;
+}
+
+
+/*
+ * Guts of the pack function.
+ *
+ * Takes a struct object, a tuple of arguments, and offset in that tuple of
+ * argument for where to start processing the arguments for packing, and a
+ * character buffer for writing the packed string.  The caller must insure
+ * that the buffer may contain the required length for packing the arguments.
+ * 0 is returned on success, 1 is returned if there is an error.
+ *
+ */
+static int
+s_pack_internal(PyStructObject *soself, PyObject *args, int offset, char* buf)
+{
+    formatcode *code;
+    /* XXX(nnorwitz): why does i need to be a local?  can we use
+       the offset parameter or do we need the wider width? */
+    Py_ssize_t i;
+
+    memset(buf, '\0', soself->s_size);
+    i = offset;
+    for (code = soself->s_codes; code->fmtdef != NULL; code++) {
+        Py_ssize_t n;
+        PyObject *v = PyTuple_GET_ITEM(args, i++);
+        const formatdef *e = code->fmtdef;
+        char *res = buf + code->offset;
+        if (e->format == 's') {
+            if (!PyString_Check(v)) {
+                PyErr_SetString(StructError,
+                                "argument for 's' must "
+                                "be a string");
+                return -1;
+            }
+            n = PyString_GET_SIZE(v);
+            if (n > code->size)
+                n = code->size;
+            if (n > 0)
+                memcpy(res, PyString_AS_STRING(v), n);
+        } else if (e->format == 'p') {
+            if (!PyString_Check(v)) {
+                PyErr_SetString(StructError,
+                                "argument for 'p' must "
+                                "be a string");
+                return -1;
+            }
+            n = PyString_GET_SIZE(v);
+            if (n > (code->size - 1))
+                n = code->size - 1;
+            if (n > 0)
+                memcpy(res + 1, PyString_AS_STRING(v), n);
+            if (n > 255)
+                n = 255;
+            *res = Py_SAFE_DOWNCAST(n, Py_ssize_t, unsigned char);
+        } else if (e->pack(res, v, e) < 0) {
+            if (strchr(integer_codes, e->format) != NULL &&
+                PyErr_ExceptionMatches(PyExc_OverflowError))
+                PyErr_Format(StructError,
+                             "integer out of range for "
+                             "'%c' format code",
+                             e->format);
+            return -1;
+        }
+    }
+
+    /* Success */
+    return 0;
+}
+
+
+PyDoc_STRVAR(s_pack__doc__,
+"S.pack(v1, v2, ...) -> string\n\
+\n\
+Return a string containing values v1, v2, ... packed according to this\n\
+Struct's format. See struct.__doc__ for more on format strings.");
+
+static PyObject *
+s_pack(PyObject *self, PyObject *args)
+{
+    PyStructObject *soself;
+    PyObject *result;
+
+    /* Validate arguments. */
+    soself = (PyStructObject *)self;
+    assert(PyStruct_Check(self));
+    assert(soself->s_codes != NULL);
+    if (PyTuple_GET_SIZE(args) != soself->s_len)
+    {
+        PyErr_Format(StructError,
+            "pack expected %zd items for packing (got %zd)", soself->s_len, PyTuple_GET_SIZE(args));
+        return NULL;
+    }
+
+    /* Allocate a new string */
+    result = PyString_FromStringAndSize((char *)NULL, soself->s_size);
+    if (result == NULL)
+        return NULL;
+
+    /* Call the guts */
+    if ( s_pack_internal(soself, args, 0, PyString_AS_STRING(result)) != 0 ) {
+        Py_DECREF(result);
+        return NULL;
+    }
+
+    return result;
+}
+
+PyDoc_STRVAR(s_pack_into__doc__,
+"S.pack_into(buffer, offset, v1, v2, ...)\n\
+\n\
+Pack the values v1, v2, ... according to this Struct's format, write \n\
+the packed bytes into the writable buffer buf starting at offset.  Note\n\
+that the offset is not an optional argument.  See struct.__doc__ for \n\
+more on format strings.");
+
+static PyObject *
+s_pack_into(PyObject *self, PyObject *args)
+{
+    PyStructObject *soself;
+    Py_buffer buf;
+    Py_ssize_t offset;
+
+    /* Validate arguments.  +1 is for the first arg as buffer. */
+    soself = (PyStructObject *)self;
+    assert(PyStruct_Check(self));
+    assert(soself->s_codes != NULL);
+    if (PyTuple_GET_SIZE(args) != (soself->s_len + 2))
+    {
+        if (PyTuple_GET_SIZE(args) == 0) {
+            PyErr_Format(StructError,
+                        "pack_into expected buffer argument");
+        }
+        else if (PyTuple_GET_SIZE(args) == 1) {
+            PyErr_Format(StructError,
+                        "pack_into expected offset argument");
+        }
+        else {
+            PyErr_Format(StructError,
+                        "pack_into expected %zd items for packing (got %zd)",
+                        soself->s_len, (PyTuple_GET_SIZE(args) - 2));
+        }
+        return NULL;
+    }
+
+    /* Extract a writable memory buffer from the first argument */
+    if (!PyArg_Parse(PyTuple_GET_ITEM(args, 0), "w*", &buf))
+        return NULL;
+
+    /* Extract the offset from the first argument */
+    offset = PyInt_AsSsize_t(PyTuple_GET_ITEM(args, 1));
+    if (offset == -1 && PyErr_Occurred()) {
+        PyBuffer_Release(&buf);
+        return NULL;
+    }
+
+    /* Support negative offsets. */
+    if (offset < 0)
+        offset += buf.len;
+
+    /* Check boundaries */
+    if (offset < 0 || (buf.len - offset) < soself->s_size) {
+        PyErr_Format(StructError,
+                     "pack_into requires a buffer of at least %zd bytes",
+                     soself->s_size);
+        PyBuffer_Release(&buf);
+        return NULL;
+    }
+
+    /* Call the guts */
+    if (s_pack_internal(soself, args, 2, (char *)buf.buf + offset) != 0) {
+        PyBuffer_Release(&buf);
+        return NULL;
+    }
+    PyBuffer_Release(&buf);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+s_get_format(PyStructObject *self, void *unused)
+{
+    Py_INCREF(self->s_format);
+    return self->s_format;
+}
+
+static PyObject *
+s_get_size(PyStructObject *self, void *unused)
+{
+    return PyInt_FromSsize_t(self->s_size);
+}
+
+PyDoc_STRVAR(s_sizeof__doc__,
+"S.__sizeof__() -> size of S in memory, in bytes");
+
+static PyObject *
+s_sizeof(PyStructObject *self, void *unused)
+{
+    Py_ssize_t size;
+
+    size = _PyObject_SIZE(Py_TYPE(self)) + sizeof(formatcode) * (self->s_len + 1);
+    return PyLong_FromSsize_t(size);
+}
+
+/* List of functions */
+
+static struct PyMethodDef s_methods[] = {
+    {"pack",            s_pack,         METH_VARARGS, s_pack__doc__},
+    {"pack_into",       s_pack_into,    METH_VARARGS, s_pack_into__doc__},
+    {"unpack",          s_unpack,       METH_O, s_unpack__doc__},
+    {"unpack_from",     (PyCFunction)s_unpack_from, METH_VARARGS|METH_KEYWORDS,
+                    s_unpack_from__doc__},
+    {"__sizeof__",      (PyCFunction)s_sizeof, METH_NOARGS, s_sizeof__doc__},
+    {NULL,       NULL}          /* sentinel */
+};
+
+PyDoc_STRVAR(s__doc__, "Compiled struct object");
+
+#define OFF(x) offsetof(PyStructObject, x)
+
+static PyGetSetDef s_getsetlist[] = {
+    {"format", (getter)s_get_format, (setter)NULL, "struct format string", NULL},
+    {"size", (getter)s_get_size, (setter)NULL, "struct size in bytes", NULL},
+    {NULL} /* sentinel */
+};
+
+static
+PyTypeObject PyStructType = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "Struct",
+    sizeof(PyStructObject),
+    0,
+    (destructor)s_dealloc,      /* tp_dealloc */
+    0,                                          /* tp_print */
+    0,                                          /* tp_getattr */
+    0,                                          /* tp_setattr */
+    0,                                          /* tp_compare */
+    0,                                          /* tp_repr */
+    0,                                          /* tp_as_number */
+    0,                                          /* tp_as_sequence */
+    0,                                          /* tp_as_mapping */
+    0,                                          /* tp_hash */
+    0,                                          /* tp_call */
+    0,                                          /* tp_str */
+    PyObject_GenericGetAttr,            /* tp_getattro */
+    PyObject_GenericSetAttr,            /* tp_setattro */
+    0,                                          /* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_WEAKREFS,/* tp_flags */
+    s__doc__,                           /* tp_doc */
+    0,                                          /* tp_traverse */
+    0,                                          /* tp_clear */
+    0,                                          /* tp_richcompare */
+    offsetof(PyStructObject, weakreflist),      /* tp_weaklistoffset */
+    0,                                          /* tp_iter */
+    0,                                          /* tp_iternext */
+    s_methods,                          /* tp_methods */
+    NULL,                               /* tp_members */
+    s_getsetlist,               /* tp_getset */
+    0,                                          /* tp_base */
+    0,                                          /* tp_dict */
+    0,                                          /* tp_descr_get */
+    0,                                          /* tp_descr_set */
+    0,                                          /* tp_dictoffset */
+    s_init,                             /* tp_init */
+    PyType_GenericAlloc,/* tp_alloc */
+    s_new,                              /* tp_new */
+    PyObject_Del,               /* tp_free */
+};
+
+
+/* ---- Standalone functions  ---- */
+
+#define MAXCACHE 100
+static PyObject *cache = NULL;
+
+static PyObject *
+cache_struct(PyObject *fmt)
+{
+    PyObject * s_object;
+
+    if (cache == NULL) {
+        cache = PyDict_New();
+        if (cache == NULL)
+            return NULL;
+    }
+
+    s_object = PyDict_GetItem(cache, fmt);
+    if (s_object != NULL) {
+        Py_INCREF(s_object);
+        return s_object;
+    }
+
+    s_object = PyObject_CallFunctionObjArgs((PyObject *)(&PyStructType), fmt, NULL);
+    if (s_object != NULL) {
+        if (PyDict_Size(cache) >= MAXCACHE)
+            PyDict_Clear(cache);
+        /* Attempt to cache the result */
+        if (PyDict_SetItem(cache, fmt, s_object) == -1)
+            PyErr_Clear();
+    }
+    return s_object;
+}
+
+PyDoc_STRVAR(clearcache_doc,
+"Clear the internal cache.");
+
+static PyObject *
+clearcache(PyObject *self)
+{
+    Py_CLEAR(cache);
+    Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(calcsize_doc,
+"Return size of C struct described by format string fmt.");
+
+static PyObject *
+calcsize(PyObject *self, PyObject *fmt)
+{
+    Py_ssize_t n;
+    PyObject *s_object = cache_struct(fmt);
+    if (s_object == NULL)
+        return NULL;
+    n = ((PyStructObject *)s_object)->s_size;
+    Py_DECREF(s_object);
+    return PyInt_FromSsize_t(n);
+}
+
+PyDoc_STRVAR(pack_doc,
+"Return string containing values v1, v2, ... packed according to fmt.");
+
+static PyObject *
+pack(PyObject *self, PyObject *args)
+{
+    PyObject *s_object, *fmt, *newargs, *result;
+    Py_ssize_t n = PyTuple_GET_SIZE(args);
+
+    if (n == 0) {
+        PyErr_SetString(PyExc_TypeError, "missing format argument");
+        return NULL;
+    }
+    fmt = PyTuple_GET_ITEM(args, 0);
+    newargs = PyTuple_GetSlice(args, 1, n);
+    if (newargs == NULL)
+        return NULL;
+
+    s_object = cache_struct(fmt);
+    if (s_object == NULL) {
+        Py_DECREF(newargs);
+        return NULL;
+    }
+    result = s_pack(s_object, newargs);
+    Py_DECREF(newargs);
+    Py_DECREF(s_object);
+    return result;
+}
+
+PyDoc_STRVAR(pack_into_doc,
+"Pack the values v1, v2, ... according to fmt.\n\
+Write the packed bytes into the writable buffer buf starting at offset.");
+
+static PyObject *
+pack_into(PyObject *self, PyObject *args)
+{
+    PyObject *s_object, *fmt, *newargs, *result;
+    Py_ssize_t n = PyTuple_GET_SIZE(args);
+
+    if (n == 0) {
+        PyErr_SetString(PyExc_TypeError, "missing format argument");
+        return NULL;
+    }
+    fmt = PyTuple_GET_ITEM(args, 0);
+    newargs = PyTuple_GetSlice(args, 1, n);
+    if (newargs == NULL)
+        return NULL;
+
+    s_object = cache_struct(fmt);
+    if (s_object == NULL) {
+        Py_DECREF(newargs);
+        return NULL;
+    }
+    result = s_pack_into(s_object, newargs);
+    Py_DECREF(newargs);
+    Py_DECREF(s_object);
+    return result;
+}
+
+PyDoc_STRVAR(unpack_doc,
+"Unpack the string containing packed C structure data, according to fmt.\n\
+Requires len(string) == calcsize(fmt).");
+
+static PyObject *
+unpack(PyObject *self, PyObject *args)
+{
+    PyObject *s_object, *fmt, *inputstr, *result;
+
+    if (!PyArg_UnpackTuple(args, "unpack", 2, 2, &fmt, &inputstr))
+        return NULL;
+
+    s_object = cache_struct(fmt);
+    if (s_object == NULL)
+        return NULL;
+    result = s_unpack(s_object, inputstr);
+    Py_DECREF(s_object);
+    return result;
+}
+
+PyDoc_STRVAR(unpack_from_doc,
+"Unpack the buffer, containing packed C structure data, according to\n\
+fmt, starting at offset. Requires len(buffer[offset:]) >= calcsize(fmt).");
+
+static PyObject *
+unpack_from(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    PyObject *s_object, *fmt, *newargs, *result;
+    Py_ssize_t n = PyTuple_GET_SIZE(args);
+
+    if (n == 0) {
+        PyErr_SetString(PyExc_TypeError, "missing format argument");
+        return NULL;
+    }
+    fmt = PyTuple_GET_ITEM(args, 0);
+    newargs = PyTuple_GetSlice(args, 1, n);
+    if (newargs == NULL)
+        return NULL;
+
+    s_object = cache_struct(fmt);
+    if (s_object == NULL) {
+        Py_DECREF(newargs);
+        return NULL;
+    }
+    result = s_unpack_from(s_object, newargs, kwds);
+    Py_DECREF(newargs);
+    Py_DECREF(s_object);
+    return result;
+}
+
+static struct PyMethodDef module_functions[] = {
+    {"_clearcache",     (PyCFunction)clearcache,        METH_NOARGS,    clearcache_doc},
+    {"calcsize",        calcsize,       METH_O, calcsize_doc},
+    {"pack",            pack,           METH_VARARGS,   pack_doc},
+    {"pack_into",       pack_into,      METH_VARARGS,   pack_into_doc},
+    {"unpack",          unpack, METH_VARARGS,   unpack_doc},
+    {"unpack_from",     (PyCFunction)unpack_from,
+                    METH_VARARGS|METH_KEYWORDS,         unpack_from_doc},
+    {NULL,       NULL}          /* sentinel */
+};
+
+
+/* Module initialization */
+
+PyDoc_STRVAR(module_doc,
+"Functions to convert between Python values and C structs represented\n\
+as Python strings. It uses format strings (explained below) as compact\n\
+descriptions of the lay-out of the C structs and the intended conversion\n\
+to/from Python values.\n\
+\n\
+The optional first format char indicates byte order, size and alignment:\n\
+  @: native order, size & alignment (default)\n\
+  =: native order, std. size & alignment\n\
+  <: little-endian, std. size & alignment\n\
+  >: big-endian, std. size & alignment\n\
+  !: same as >\n\
+\n\
+The remaining chars indicate types of args and must match exactly;\n\
+these can be preceded by a decimal repeat count:\n\
+  x: pad byte (no data); c:char; b:signed byte; B:unsigned byte;\n\
+  ?: _Bool (requires C99; if not available, char is used instead)\n\
+  h:short; H:unsigned short; i:int; I:unsigned int;\n\
+  l:long; L:unsigned long; f:float; d:double.\n\
+Special cases (preceding decimal count indicates length):\n\
+  s:string (array of char); p: pascal string (with count byte).\n\
+Special case (only available in native format):\n\
+  P:an integer type that is wide enough to hold a pointer.\n\
+Special case (not in native mode unless 'long long' in platform C):\n\
+  q:long long; Q:unsigned long long\n\
+Whitespace between formats is ignored.\n\
+\n\
+The variable struct.error is an exception raised on errors.\n");
+
+PyMODINIT_FUNC
+init_struct(void)
+{
+    PyObject *ver, *m;
+
+    ver = PyString_FromString("0.2");
+    if (ver == NULL)
+        return;
+
+    m = Py_InitModule3("_struct", module_functions, module_doc);
+    if (m == NULL)
+        return;
+
+    Py_TYPE(&PyStructType) = &PyType_Type;
+    if (PyType_Ready(&PyStructType) < 0)
+        return;
+
+    /* This speed trick can't be used until overflow masking goes
+       away, because native endian always raises exceptions
+       instead of overflow masking. */
+
+    /* Check endian and swap in faster functions */
+    {
+        int one = 1;
+        formatdef *native = native_table;
+        formatdef *other, *ptr;
+        if ((int)*(unsigned char*)&one)
+            other = lilendian_table;
+        else
+            other = bigendian_table;
+        /* Scan through the native table, find a matching
+           entry in the endian table and swap in the
+           native implementations whenever possible
+           (64-bit platforms may not have "standard" sizes) */
+        while (native->format != '\0' && other->format != '\0') {
+            ptr = other;
+            while (ptr->format != '\0') {
+                if (ptr->format == native->format) {
+                    /* Match faster when formats are
+                       listed in the same order */
+                    if (ptr == other)
+                        other++;
+                    /* Only use the trick if the
+                       size matches */
+                    if (ptr->size != native->size)
+                        break;
+                    /* Skip float and double, could be
+                       "unknown" float format */
+                    if (ptr->format == 'd' || ptr->format == 'f')
+                        break;
+                    ptr->pack = native->pack;
+                    ptr->unpack = native->unpack;
+                    break;
+                }
+                ptr++;
+            }
+            native++;
+        }
+    }
+
+    /* Add some symbolic constants to the module */
+    if (StructError == NULL) {
+        StructError = PyErr_NewException("struct.error", NULL, NULL);
+        if (StructError == NULL)
+            return;
+    }
+
+    Py_INCREF(StructError);
+    PyModule_AddObject(m, "error", StructError);
+
+    Py_INCREF((PyObject*)&PyStructType);
+    PyModule_AddObject(m, "Struct", (PyObject*)&PyStructType);
+
+    PyModule_AddObject(m, "__version__", ver);
+
+    PyModule_AddIntConstant(m, "_PY_STRUCT_RANGE_CHECKING", 1);
+    PyModule_AddIntConstant(m, "_PY_STRUCT_FLOAT_COERCE", 1);
+}