[Python-checkins] r46144 - in python/trunk: Lib/struct.py Modules/_struct.c Modules/structmodule.c
bob.ippolito
python-checkins at python.org
Tue May 23 21:12:41 CEST 2006
Author: bob.ippolito
Date: Tue May 23 21:12:41 2006
New Revision: 46144
Added:
python/trunk/Lib/struct.py (contents, props changed)
python/trunk/Modules/_struct.c (contents, props changed)
Removed:
python/trunk/Modules/structmodule.c
Log:
patch #1493701: performance enhancements for struct module
Added: python/trunk/Lib/struct.py
==============================================================================
--- (empty file)
+++ python/trunk/Lib/struct.py Tue May 23 21:12:41 2006
@@ -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)
+
Added: python/trunk/Modules/_struct.c
==============================================================================
--- (empty file)
+++ python/trunk/Modules/_struct.c Tue May 23 21:12:41 2006
@@ -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);
+}
Deleted: /python/trunk/Modules/structmodule.c
==============================================================================
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