/Modules/_struct.c
C | 2171 lines | 1808 code | 253 blank | 110 comment | 403 complexity | f5e01344d6cd89d1ea0e8b18b427e37d MD5 | raw file
Possible License(s): 0BSD, BSD-3-Clause
- /* 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
- /* If PY_STRUCT_OVERFLOW_MASKING is defined, the struct module will wrap all input
- numbers for explicit endians such that they fit in the given type, much
- like explicit casting in C. A warning will be raised if the number did
- not originally fit within the range of the requested type. If it is
- not defined, then all range errors and overflow will be struct.error
- exceptions. */
- #define PY_STRUCT_OVERFLOW_MASKING 1
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- static PyObject *pylong_ulong_mask = NULL;
- static PyObject *pyint_zero = NULL;
- #endif
- /* If PY_STRUCT_FLOAT_COERCE is defined, the struct module will allow float
- arguments for integer formats with a warning for backwards
- compatibility. */
- #define PY_STRUCT_FLOAT_COERCE 1
- #ifdef PY_STRUCT_FLOAT_COERCE
- #define FLOAT_COERCE "integer argument expected, got float"
- #endif
- /* 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
- /* 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 = Py_TYPE(v)->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()) {
- #ifdef PY_STRUCT_FLOAT_COERCE
- if (PyFloat_Check(v)) {
- PyObject *o;
- int res;
- PyErr_Clear();
- if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 2) < 0)
- return -1;
- o = PyNumber_Int(v);
- if (o == NULL)
- return -1;
- res = get_long(o, p);
- Py_DECREF(o);
- return res;
- }
- #endif
- 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 */
- #ifndef PY_STRUCT_OVERFLOW_MASKING
- 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;
- }
- if (get_long(v, (long *)p) < 0)
- return -1;
- if (((long)*p) < 0) {
- PyErr_SetString(StructError,
- "unsigned argument is < 0");
- return -1;
- }
- return 0;
- }
- #endif /* PY_STRUCT_OVERFLOW_MASKING */
- #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
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- /* Helper routine to get a Python integer and raise the appropriate error
- if it isn't one */
- #define INT_OVERFLOW "struct integer overflow masking is deprecated"
- static int
- get_wrapped_long(PyObject *v, long *p)
- {
- if (get_long(v, p) < 0) {
- if (PyLong_Check(v) &&
- PyErr_ExceptionMatches(PyExc_OverflowError)) {
- PyObject *wrapped;
- long x;
- PyErr_Clear();
- #ifdef PY_STRUCT_FLOAT_COERCE
- if (PyFloat_Check(v)) {
- PyObject *o;
- int res;
- PyErr_Clear();
- if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 2) < 0)
- return -1;
- o = PyNumber_Int(v);
- if (o == NULL)
- return -1;
- res = get_wrapped_long(o, p);
- Py_DECREF(o);
- return res;
- }
- #endif
- if (PyErr_WarnEx(PyExc_DeprecationWarning, INT_OVERFLOW, 2) < 0)
- return -1;
- wrapped = PyNumber_And(v, pylong_ulong_mask);
- if (wrapped == NULL)
- return -1;
- x = (long)PyLong_AsUnsignedLong(wrapped);
- Py_DECREF(wrapped);
- if (x == -1 && PyErr_Occurred())
- return -1;
- *p = x;
- } else {
- return -1;
- }
- }
- return 0;
- }
- static int
- get_wrapped_ulong(PyObject *v, unsigned long *p)
- {
- long x = (long)PyLong_AsUnsignedLong(v);
- if (x == -1 && PyErr_Occurred()) {
- PyObject *wrapped;
- PyErr_Clear();
- #ifdef PY_STRUCT_FLOAT_COERCE
- if (PyFloat_Check(v)) {
- PyObject *o;
- int res;
- PyErr_Clear();
- if (PyErr_WarnEx(PyExc_DeprecationWarning, FLOAT_COERCE, 2) < 0)
- return -1;
- o = PyNumber_Int(v);
- if (o == NULL)
- return -1;
- res = get_wrapped_ulong(o, p);
- Py_DECREF(o);
- return res;
- }
- #endif
- wrapped = PyNumber_And(v, pylong_ulong_mask);
- if (wrapped == NULL)
- return -1;
- if (PyErr_WarnEx(PyExc_DeprecationWarning, INT_OVERFLOW, 2) < 0) {
- Py_DECREF(wrapped);
- return -1;
- }
- x = (long)PyLong_AsUnsignedLong(wrapped);
- Py_DECREF(wrapped);
- if (x == -1 && PyErr_Occurred())
- return -1;
- }
- *p = (unsigned long)x;
- return 0;
- }
- #define RANGE_ERROR(x, f, flag, mask) \
- do { \
- if (_range_error(f, flag) < 0) \
- return -1; \
- else \
- (x) &= (mask); \
- } while (0)
- #else
- #define get_wrapped_long get_long
- #define get_wrapped_ulong get_ulong
- #define RANGE_ERROR(x, f, flag, mask) return _range_error(f, flag)
- #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);
- }
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- {
- PyObject *ptype, *pvalue, *ptraceback;
- PyObject *msg;
- int rval;
- PyErr_Fetch(&ptype, &pvalue, &ptraceback);
- assert(pvalue != NULL);
- msg = PyObject_Str(pvalue);
- Py_XDECREF(ptype);
- Py_XDECREF(pvalue);
- Py_XDECREF(ptraceback);
- if (msg == NULL)
- return -1;
- rval = PyErr_WarnEx(PyExc_DeprecationWarning,
- PyString_AS_STRING(msg), 2);
- Py_DECREF(msg);
- if (rval == 0)
- return 0;
- }
- #endif
- 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;
- }
- *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,
- "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)))
- RANGE_ERROR(x, f, 0, -1);
- #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_wrapped_ulong(v, &x) < 0)
- return -1;
- y = (unsigned int)x;
- #if (SIZEOF_LONG > SIZEOF_INT)
- if (x > ((unsigned long)UINT_MAX))
- RANGE_ERROR(y, f, 1, -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_wrapped_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)
- {
- BOOL_TYPE y;
- y = PyObject_IsTrue(v);
- memcpy(p, (char *)&y, sizeof y);
- 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;
- if (get_wrapped_long(v, &x) < 0)
- return -1;
- i = f->size;
- if (i != SIZEOF_LONG) {
- if ((i == 2) && (x < -32768 || x > 32767))
- RANGE_ERROR(x, f, 0, 0xffffL);
- #if (SIZEOF_LONG != 4)
- else if ((i == 4) && (x < -2147483648L || x > 2147483647L))
- RANGE_ERROR(x, f, 0, 0xffffffffL);
- #endif
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- else if ((i == 1) && (x < -128 || x > 127))
- RANGE_ERROR(x, f, 0, 0xffL);
- #endif
- }
- 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;
- Py_ssize_t i;
- if (get_wrapped_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)
- RANGE_ERROR(x, f, 1, maxint - 1);
- }
- 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 int
- bp_bool(char *p, PyObject *v, const formatdef *f)
- {
- char y;
- y = PyObject_IsTrue(v);
- memcpy(p, (char *)&y, sizeof y);
- return 0;
- }
- static formatdef bigendian_table[] = {
- {'x', 1, 0, NULL},
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- /* Native packers do range checking without overflow masking. */
- {'b', 1, 0, nu_byte, bp_int},
- {'B', 1, 0, nu_ubyte, bp_uint},
- #else
- {'b', 1, 0, nu_byte, np_byte},
- {'B', 1, 0, nu_ubyte, np_ubyte},
- #endif
- {'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;
- if (get_wrapped_long(v, &x) < 0)
- return -1;
- i = f->size;
- if (i != SIZEOF_LONG) {
- if ((i == 2) && (x < -32768 || x > 32767))
- RANGE_ERROR(x, f, 0, 0xffffL);
- #if (SIZEOF_LONG != 4)
- else if ((i == 4) && (x < -2147483648L || x > 2147483647L))
- RANGE_ERROR(x, f, 0, 0xffffffffL);
- #endif
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- else if ((i == 1) && (x < -128 || x > 127))
- RANGE_ERROR(x, f, 0, 0xffL);
- #endif
- }
- 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;
- Py_ssize_t i;
- if (get_wrapped_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)
- RANGE_ERROR(x, f, 1, maxint - 1);
- }
- 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},
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- /* Native packers do range checking without overflow masking. */
- {'b', 1, 0, nu_byte, lp_int},
- {'B', 1, 0, nu_ubyte, lp_uint},
- #else
- {'b', 1, 0, nu_byte, np_byte},
- {'B', 1, 0, nu_ubyte, np_ubyte},
- #endif
- {'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 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(Py_ssize_t size, char 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;
- Py_ssize_t size, len, num, itemsize, x;
- 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') {
- 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;
- }
- 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;
- }
- }
- /* 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;
- }
- 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;
- }
- 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, "S:Struct", kwlist,
- &o_format))
- return -1;
- Py_INCREF(o_format);
- Py_CLEAR(soself->s_format);
- soself->s_format = o_format;
- 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)
- {
- 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", &start, &len))
- goto fail;
- if (soself->s_size != len)
- goto fail;
- result = s_unpack_internal(soself, start);
- Py_DECREF(args);
- 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};
- #if (PY_VERSION_HEX < 0x02050000)
- static char *fmt = "z#|i:unpack_from";
- #else
- static char *fmt = "z#|n:unpack_from";
- #endif
- Py_ssize_t buffer_len = 0, offset = 0;
- char *buffer = NULL;
- PyStructObject *soself = (PyStructObject *)self;
- assert(PyStruct_Check(self));
- assert(soself->s_codes != NULL);
- if (!PyArg_ParseTupleAndKeywords(args, kwds, fmt, kwlist,
- &buffer, &buffer_len, &offset))
- return NULL;
- if (buffer == NULL) {
- PyErr_Format(StructError,
- "unpack_from requires a buffer argument");
- 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);
- return NULL;
- }
- return s_unpack_internal(soself, buffer + offset);
- }
- /*
- * 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 (PyLong_Check(v) && PyErr_ExceptionMatches(PyExc_OverflowError))
- PyErr_SetString(StructError,
- "long too large to convert to int");
- 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 requires exactly %zd arguments", soself->s_len);
- 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;
- char *buffer;
- Py_ssize_t buffer_len, 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))
- {
- PyErr_Format(StructError,
- "pack_into requires exactly %zd arguments",
- (soself->s_len + 2));
- return NULL;
- }
- /* Extract a writable memory buffer from the first argument */
- if ( PyObject_AsWriteBuffer(PyTuple_GET_ITEM(args, 0),
- (void**)&buffer, &buffer_len) == -1 ) {
- return NULL;
- }
- assert( buffer_len >= 0 );
- /* Extract the offset from the first argument */
- offset = PyInt_AsSsize_t(PyTuple_GET_ITEM(args, 1));
- if (offset == -1 && PyErr_Occurred())
- return NULL;
- /* Support negative offsets. */
- if (offset < 0)
- offset += buffer_len;
- /* Check boundaries */
- if (offset < 0 || (buffer_len - offset) < soself->s_size) {
- PyErr_Format(StructError,
- "pack_into requires a buffer of at least %zd bytes",
- soself->s_size);
- return NULL;
- }
- /* Call the guts */
- if ( s_pack_internal(soself, args, 2, buffer + offset) != 0 ) {
- return NULL;
- }
- 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);
- }
- /* 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__},
- {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.\n\
- Python strings are used to hold the data representing the C struct\n\
- and also as format strings to describe the layout of data in the C struct.\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\
- 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;
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- if (pyint_zero == NULL) {
- pyint_zero = PyInt_FromLong(0);
- if (pyint_zero == NULL)
- return;
- }
- if (pylong_ulong_mask == NULL) {
- #if (SIZEOF_LONG == 4)
- pylong_ulong_mask = PyLong_FromString("FFFFFFFF", NULL, 16);
- #else
- pylong_ulong_mask = PyLong_FromString("FFFFFFFFFFFFFFFF", NULL, 16);
- #endif
- if (pylong_ulong_mask == NULL)
- return;
- }
- #else
- /* 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++;
- }
- }
- #endif
- /* 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);
- #ifdef PY_STRUCT_OVERFLOW_MASKING
- PyModule_AddIntConstant(m, "_PY_STRUCT_OVERFLOW_MASKING", 1);
- #endif
- #ifdef PY_STRUCT_FLOAT_COERCE
- PyModule_AddIntConstant(m, "_PY_STRUCT_FLOAT_COERCE", 1);
- #endif
- }