[Python-checkins] r59687 - in python/trunk: Lib/struct.py Modules/_struct.c
raymond.hettinger
python-checkins at python.org
Fri Jan 4 01:01:16 CET 2008
Author: raymond.hettinger
Date: Fri Jan 4 01:01:15 2008
New Revision: 59687
Modified:
python/trunk/Lib/struct.py
python/trunk/Modules/_struct.c
Log:
Finish-up the struct module optimizations started at the Iceland NFS sprint.
Modified: python/trunk/Lib/struct.py
==============================================================================
--- python/trunk/Lib/struct.py (original)
+++ python/trunk/Lib/struct.py Fri Jan 4 01:01:15 2008
@@ -1,99 +1 @@
-"""
-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 pack_into(fmt, buf, offset, *args):
- """
- Pack the values v1, v2, ... according to fmt, write
- the packed bytes into the writable buffer buf starting at offset.
- See struct.__doc__ for more on format strings.
- """
- try:
- o = _cache[fmt]
- except KeyError:
- o = _compile(fmt)
- return o.pack_into(buf, offset, *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)
-
-def unpack_from(fmt, buf, offset=0):
- """
- Unpack the buffer, containing packed C structure data, according to
- fmt starting at offset. Requires len(buffer[offset:]) >= calcsize(fmt).
- See struct.__doc__ for more on format strings.
- """
- try:
- o = _cache[fmt]
- except KeyError:
- o = _compile(fmt)
- return o.unpack_from(buf, offset)
+from _struct import *
Modified: python/trunk/Modules/_struct.c
==============================================================================
--- python/trunk/Modules/_struct.c (original)
+++ python/trunk/Modules/_struct.c Fri Jan 4 01:01:15 2008
@@ -1847,12 +1847,214 @@
PyObject_Del, /* tp_free */
};
+
+/* ---- Standalone functions ---- */
+
+#define MAXCACHE 100
+
+static PyObject *
+cache_struct(PyObject *fmt)
+{
+ static PyObject *cache = NULL;
+ 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(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[] = {
+ {"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 *m = Py_InitModule("_struct", NULL);
+ PyObject *ver, *m;
+
+ ver = PyString_FromString("0.2");
+ if (ver == NULL)
+ return;
+
+ m = Py_InitModule3("_struct", module_functions, module_doc);
if (m == NULL)
return;
@@ -1933,6 +2135,8 @@
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);
More information about the Python-checkins
mailing list