]> granicus.if.org Git - python/commitdiff
patch #1493701: performance enhancements for struct module
authorBob Ippolito <bob@redivi.com>
Tue, 23 May 2006 19:12:41 +0000 (19:12 +0000)
committerBob Ippolito <bob@redivi.com>
Tue, 23 May 2006 19:12:41 +0000 (19:12 +0000)
Lib/struct.py [new file with mode: 0644]
Modules/_struct.c [new file with mode: 0644]
Modules/structmodule.c [deleted file]

diff --git a/Lib/struct.py b/Lib/struct.py
new file mode 100644 (file)
index 0000000..aa7af71
--- /dev/null
@@ -0,0 +1,76 @@
+"""
+Functions to convert between Python values and C structs.
+Python strings are used to hold the data representing the C struct
+and also as format strings to describe the layout of data in the C struct.
+
+The optional first format char indicates byte order, size and alignment:
+ @: native order, size & alignment (default)
+ =: native order, std. size & alignment
+ <: little-endian, std. size & alignment
+ >: big-endian, std. size & alignment
+ !: same as >
+
+The remaining chars indicate types of args and must match exactly;
+these can be preceded by a decimal repeat count:
+ x: pad byte (no data); c:char; b:signed byte; B:unsigned byte;
+ h:short; H:unsigned short; i:int; I:unsigned int;
+ l:long; L:unsigned long; f:float; d:double.
+Special cases (preceding decimal count indicates length):
+ s:string (array of char); p: pascal string (with count byte).
+Special case (only available in native format):
+ P:an integer type that is wide enough to hold a pointer.
+Special case (not in native mode unless 'long long' in platform C):
+ q:long long; Q:unsigned long long
+Whitespace between formats is ignored.
+
+The variable struct.error is an exception raised on errors.
+"""
+__version__ = '0.1'
+
+from _struct import Struct, error
+
+_MAXCACHE = 100
+_cache = {}
+
+def _compile(fmt):
+    # Internal: compile struct pattern
+    if len(_cache) >= _MAXCACHE:
+        _cache.clear()
+    s = Struct(fmt)
+    _cache[fmt] = s
+    return s
+
+def calcsize(fmt):
+    """
+    Return size of C struct described by format string fmt.
+    See struct.__doc__ for more on format strings.
+    """
+    try:
+        o = _cache[fmt]
+    except KeyError:
+        o = _compile(fmt)
+    return o.size
+    
+def pack(fmt, *args):
+    """
+    Return string containing values v1, v2, ... packed according to fmt.
+    See struct.__doc__ for more on format strings.
+    """
+    try:
+        o = _cache[fmt]
+    except KeyError:
+        o = _compile(fmt)
+    return o.pack(*args)
+
+def unpack(fmt, s):
+    """
+    Unpack the string, containing packed C structure data, according
+    to fmt.  Requires len(string)==calcsize(fmt).
+    See struct.__doc__ for more on format strings.
+    """
+    try:
+        o = _cache[fmt]
+    except KeyError:
+        o = _compile(fmt)
+    return o.unpack(s)
+    
diff --git a/Modules/_struct.c b/Modules/_struct.c
new file mode 100644 (file)
index 0000000..838e4e4
--- /dev/null
@@ -0,0 +1,1355 @@
+/* struct module -- pack values into and (out of) strings */
+
+/* New version supporting byte order, alignment and size options,
+   character strings, and unsigned numbers */
+
+#include "Python.h"
+#include "structseq.h"
+#include "structmember.h"
+#include <ctype.h>
+
+
+/* compatibility macros */
+#if (PY_VERSION_HEX < 0x02050000)
+typedef int Py_ssize_t;
+#endif
+
+
+
+/* The translation function for each format character is table driven */
+
+typedef struct _formatdef {
+       char format;
+       int size;
+       int alignment;
+       PyObject* (*unpack)(const char *,
+                           const struct _formatdef *);
+       int (*pack)(char *, PyObject *,
+                   const struct _formatdef *);
+} formatdef;
+
+typedef struct _formatcode {
+       const struct _formatdef *fmtdef;
+       int offset;
+       int repeat;
+} formatcode;
+
+/* Struct object interface */
+
+typedef struct {
+       PyObject_HEAD
+       int s_size;
+       int s_len;
+       formatcode *s_codes;
+       PyObject *s_format;
+       PyObject *weakreflist; /* List of weak references */
+} PyStructObject;
+
+PyAPI_DATA(PyTypeObject) PyStruct_Type;
+
+#define PyStruct_Check(op) PyObject_TypeCheck(op, &PyStruct_Type)
+#define PyStruct_CheckExact(op) ((op)->ob_type == &PyStruct_Type)
+
+
+/* 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
+
+#define STRINGIFY(x)    #x
+
+#ifdef __powerc
+#pragma options align=reset
+#endif
+
+/* Helper to get a PyLongObject by hook or by crook.  Caller should decref. */
+
+static PyObject *
+get_pylong(PyObject *v)
+{
+       PyNumberMethods *m;
+
+       assert(v != NULL);
+       if (PyInt_Check(v))
+               return PyLong_FromLong(PyInt_AS_LONG(v));
+       if (PyLong_Check(v)) {
+               Py_INCREF(v);
+               return v;
+       }
+       m = v->ob_type->tp_as_number;
+       if (m != NULL && m->nb_long != NULL) {
+               v = m->nb_long(v);
+               if (v == NULL)
+                       return NULL;
+               if (PyLong_Check(v))
+                       return v;
+               Py_DECREF(v);
+       }
+       PyErr_SetString(StructError,
+                       "cannot convert argument to long");
+       return NULL;
+}
+
+/* Helper routine to get a Python integer and raise the appropriate error
+   if it isn't one */
+
+static int
+get_long(PyObject *v, long *p)
+{
+       long x = PyInt_AsLong(v);
+       if (x == -1 && PyErr_Occurred()) {
+               if (PyErr_ExceptionMatches(PyExc_TypeError))
+                       PyErr_SetString(StructError,
+                                       "required argument is not an integer");
+               return -1;
+       }
+       *p = x;
+       return 0;
+}
+
+
+/* Same, but handling unsigned long */
+
+static int
+get_ulong(PyObject *v, unsigned long *p)
+{
+       if (PyLong_Check(v)) {
+               unsigned long x = PyLong_AsUnsignedLong(v);
+               if (x == (unsigned long)(-1) && PyErr_Occurred())
+                       return -1;
+               *p = x;
+               return 0;
+       }
+       else {
+               return get_long(v, (long *)p);
+       }
+}
+
+#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);
+}
+
+
+/* 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);
+       return PyLong_FromUnsignedLong((unsigned long)x);
+}
+
+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);
+       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);
+       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);
+       return PyLong_FromUnsignedLongLong(x);
+}
+
+#endif
+
+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;
+       }
+       *p = (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,
+                               "short 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;
+       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;
+       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_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},
+       {'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},
+#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
+       {0}
+};
+
+/* Big-endian routines. *****************************************************/
+
+static PyObject *
+bu_int(const char *p, const formatdef *f)
+{
+       long x = 0;
+       int i = f->size;
+       do {
+               x = (x<<8) | (*p++ & 0xFF);
+       } 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;
+       int i = f->size;
+       do {
+               x = (x<<8) | (*p++ & 0xFF);
+       } while (--i > 0);
+       if (f->size >= 4)
+               return PyLong_FromUnsignedLong(x);
+       else
+               return PyInt_FromLong((long)x);
+}
+
+static PyObject *
+bu_longlong(const char *p, const formatdef *f)
+{
+       return _PyLong_FromByteArray((const unsigned char *)p,
+                                     8,
+                                     0, /* little-endian */
+                                     1  /* signed */);
+}
+
+static PyObject *
+bu_ulonglong(const char *p, const formatdef *f)
+{
+       return _PyLong_FromByteArray((const unsigned char *)p,
+                                     8,
+                                     0, /* little-endian */
+                                     0  /* signed */);
+}
+
+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 int
+bp_int(char *p, PyObject *v, const formatdef *f)
+{
+       long x;
+       int i;
+       if (get_long(v, &x) < 0)
+               return -1;
+       i = f->size;
+       do {
+               p[--i] = (char)x;
+               x >>= 8;
+       } while (i > 0);
+       return 0;
+}
+
+static int
+bp_uint(char *p, PyObject *v, const formatdef *f)
+{
+       unsigned long x;
+       int i;
+       if (get_ulong(v, &x) < 0)
+               return -1;
+       i = f->size;
+       do {
+               p[--i] = (char)x;
+               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 formatdef bigendian_table[] = {
+       {'x',   1,              0,              NULL},
+       {'b',   1,              0,              bu_int,         bp_int},
+       {'B',   1,              0,              bu_uint,        bp_int},
+       {'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},
+       {'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;
+       int i = f->size;
+       do {
+               x = (x<<8) | (p[--i] & 0xFF);
+       } 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;
+       int i = f->size;
+       do {
+               x = (x<<8) | (p[--i] & 0xFF);
+       } while (i > 0);
+       if (f->size >= 4)
+               return PyLong_FromUnsignedLong(x);
+       else
+               return PyInt_FromLong((long)x);
+}
+
+static PyObject *
+lu_longlong(const char *p, const formatdef *f)
+{
+       return _PyLong_FromByteArray((const unsigned char *)p,
+                                     8,
+                                     1, /* little-endian */
+                                     1  /* signed */);
+}
+
+static PyObject *
+lu_ulonglong(const char *p, const formatdef *f)
+{
+       return _PyLong_FromByteArray((const unsigned char *)p,
+                                     8,
+                                     1, /* little-endian */
+                                     0  /* signed */);
+}
+
+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;
+       int i;
+       if (get_long(v, &x) < 0)
+               return -1;
+       i = f->size;
+       do {
+               *p++ = (char)x;
+               x >>= 8;
+       } while (--i > 0);
+       return 0;
+}
+
+static int
+lp_uint(char *p, PyObject *v, const formatdef *f)
+{
+       unsigned long x;
+       int i;
+       if (get_ulong(v, &x) < 0)
+               return -1;
+       i = f->size;
+       do {
+               *p++ = (char)x;
+               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,              lu_int,         lp_int},
+       {'B',   1,              0,              lu_uint,        lp_int},
+       {'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},
+       {'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 aligment! */
+               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 */
+
+static int
+align(int size, int c, const formatdef *e)
+{
+       if (e->format == c) {
+               if (e->alignment) {
+                       size = ((size + e->alignment - 1)
+                               / e->alignment)
+                               * e->alignment;
+               }
+       }
+       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;
+       int size, len, numcodes, num, itemsize, x;
+
+       fmt = PyString_AS_STRING(self->s_format);
+
+       f = whichtable((char **)&fmt);
+       
+       s = fmt;
+       size = 0;
+       len = 0;
+       numcodes = 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') {
+                               x = num*10 + (c - '0');
+                               if (x/10 != num) {
+                                       PyErr_SetString(
+                                               StructError,
+                                               "overflow in item count");
+                                       return -1;
+                               }
+                               num = x;
+                       }
+                       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;
+               }
+               if (c != 'x') numcodes++;
+
+               itemsize = e->size;
+               size = align(size, c, e);
+               x = num * itemsize;
+               size += x;
+               if (x/itemsize != num || size < 0) {
+                       PyErr_SetString(StructError,
+                                       "total struct size too long");
+                       return -1;
+               }
+       }
+
+       self->s_size = size;
+       self->s_len = len;
+       codes = PyMem_MALLOC((numcodes + 1) * sizeof(formatcode));
+       if (codes == NULL) {
+               PyErr_NoMemory();
+               return -1;
+       }
+       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 != 'x') {
+                       codes->offset = size;
+                       codes->repeat = num;
+                       codes->fmtdef = e;
+                       codes++;
+               }
+               size += num * e->size;
+       }
+       codes->fmtdef = NULL;
+       codes->offset = -1;
+       codes->repeat = -1;
+       
+       return 0;
+}
+
+static PyObject *
+s_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+       PyObject *self;
+       static PyObject *not_yet_string;
+
+       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, "S:Struct", kwlist,
+                                        &o_format))
+               return -1;
+
+       Py_INCREF(o_format);
+       Py_XDECREF(soself->s_format);
+       soself->s_format = o_format;
+       
+       ret = prepare_s(soself);
+       return ret;
+}
+
+static void
+s_dealloc(PyStructObject *s)
+{
+       int sts = 0;
+       if (s->weakreflist != NULL)
+               PyObject_ClearWeakRefs((PyObject *)s);
+       if (s->s_codes != NULL) {
+               PyMem_FREE(s->s_codes);
+       }
+       Py_XDECREF(s->s_format);
+       s->ob_type->tp_free((PyObject *)s);
+}
+
+PyDoc_STRVAR(s_unpack__doc__,
+"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)
+{
+       PyStructObject *soself;
+       PyObject *result;
+       char *restart;
+       formatcode *code;
+       Py_ssize_t i;
+       
+       soself = (PyStructObject *)self;
+       assert(PyStruct_Check(self));
+       assert(soself->s_codes != NULL);        
+       if (inputstr == NULL || !PyString_Check(inputstr) ||
+           PyString_GET_SIZE(inputstr) != soself->s_size) {
+               PyErr_Format(StructError,
+                       "unpack requires a string argument of length %d", soself->s_size);
+               return NULL;
+       }
+       result = PyTuple_New(soself->s_len);
+       if (result == NULL)
+               return NULL;
+       
+
+       restart = PyString_AS_STRING(inputstr);
+       i = 0;
+       for (code = soself->s_codes; code->fmtdef != NULL; code++) {
+               Py_ssize_t n;
+               PyObject *v;
+               const formatdef *e = code->fmtdef;
+               const char *res = restart + code->offset;
+               if (e->format == 's') {
+                       v = PyString_FromStringAndSize(res, code->repeat);
+                       if (v == NULL)
+                               goto fail;
+                       PyTuple_SET_ITEM(result, i++, v);
+               } else if (e->format == 'p') {
+                       n = *(unsigned char*)res;
+                       if (n >= code->repeat)
+                               n = code->repeat - 1;
+                       v = PyString_FromStringAndSize(res + 1, n);
+                       if (v == NULL)
+                               goto fail;
+                       PyTuple_SET_ITEM(result, i++, v);
+               } else {
+                       for (n = 0; n < code->repeat; n++) {
+                               v = e->unpack(res, e);
+                               if (v == NULL)
+                                       goto fail;
+                               PyTuple_SET_ITEM(result, i++, v);
+                               res += e->size;
+                       }
+               }
+       }
+
+       return result;
+fail:
+       Py_DECREF(result);
+       return NULL;
+};
+
+
+PyDoc_STRVAR(s_pack__doc__,
+"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;
+       char *restart;
+       formatcode *code;
+       Py_ssize_t i;
+       
+       soself = (PyStructObject *)self;
+       assert(PyStruct_Check(self));
+       assert(soself->s_codes != NULL);
+       if (args == NULL || !PyTuple_Check(args) ||
+           PyTuple_GET_SIZE(args) != soself->s_len)
+       {
+               PyErr_Format(StructError,
+                       "pack requires exactly %d arguments", soself->s_len);
+               return NULL;
+       }
+       
+       result = PyString_FromStringAndSize((char *)NULL, soself->s_size);
+       if (result == NULL)
+               return NULL;
+       
+       restart = PyString_AS_STRING(result);
+       memset(restart, '\0', soself->s_size);
+       i = 0;
+       for (code = soself->s_codes; code->fmtdef != NULL; code++) {
+               Py_ssize_t n;
+               PyObject *v;
+               const formatdef *e = code->fmtdef;
+               char *res = restart + code->offset;
+               if (e->format == 's') {
+                       v = PyTuple_GET_ITEM(args, i++);
+                       if (!PyString_Check(v)) {
+                               PyErr_SetString(StructError,
+                                               "argument for 's' must be a string");
+                               goto fail;
+                       }
+                       n = PyString_GET_SIZE(v);
+                       if (n > code->repeat)
+                               n = code->repeat;
+                       if (n > 0)
+                               memcpy(res, PyString_AS_STRING(v), n);
+               } else if (e->format == 'p') {
+                       v = PyTuple_GET_ITEM(args, i++);
+                       if (!PyString_Check(v)) {
+                               PyErr_SetString(StructError,
+                                               "argument for 'p' must be a string");
+                               goto fail;
+                       }
+                       n = PyString_GET_SIZE(v);
+                       if (n > (code->repeat - 1))
+                               n = code->repeat - 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 {
+                       for (n = 0; n < code->repeat; n++) {
+                               v = PyTuple_GET_ITEM(args, i++);
+                               if (e->pack(res, v, e) < 0)
+                                       goto fail;
+                               res += e->size;
+                       }
+               }
+       }
+       
+       return result;
+
+fail:
+       Py_DECREF(result);
+       return NULL;
+       
+}
+
+
+/* List of functions */
+
+static struct PyMethodDef s_methods[] = {
+       {"pack",        s_pack,         METH_VARARGS, s_pack__doc__},
+       {"unpack",      s_unpack,       METH_O, s_unpack__doc__},
+       {NULL,   NULL}          /* sentinel */
+};
+
+PyDoc_STRVAR(s__doc__, "Compiled struct object");
+
+#define OFF(x) offsetof(PyStructObject, x)
+
+static PyMemberDef s_memberlist[] = {
+       {"format",      T_OBJECT,       OFF(s_format),  RO,
+        "struct format string"},
+       {"size",        T_INT,          OFF(s_size),    RO,
+        "struct size in bytes"},
+       {"_len",        T_INT,          OFF(s_len),     RO,
+        "number of items expected in tuple"},
+       {NULL}  /* Sentinel */
+};
+
+
+static
+PyTypeObject PyStructType = {
+       PyObject_HEAD_INIT(&PyType_Type)
+       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 */
+       s_memberlist,                           /* tp_members */
+       0,                                      /* 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 */
+};
+
+/* Module initialization */
+
+PyMODINIT_FUNC
+init_struct(void)
+{
+       PyObject *m = Py_InitModule("_struct", NULL);
+       if (m == NULL)
+               return;
+
+       /* 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);
+}
diff --git a/Modules/structmodule.c b/Modules/structmodule.c
deleted file mode 100644 (file)
index e69de29..0000000