dulwich/_objects.c

   1 /*
   2  * Copyright (C) 2009 Jelmer Vernooij <jelmer@samba.org>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; version 2
   7  * of the License or (at your option) a later version of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  17  * MA  02110-1301, USA.
  18  */
  19
  20 #include <Python.h>
  21 #include <stdlib.h>
  22 #include <sys/stat.h>
  23
  24 #if (PY_VERSION_HEX < 0x02050000)
  25 typedef int Py_ssize_t;
  26 #endif
  27
  28 #if defined(__MINGW32_VERSION) || defined(__APPLE__)
  29 size_t rep_strnlen(char *text, size_t maxlen);
  30 size_t rep_strnlen(char *text, size_t maxlen)
  31 {
  32         const char *last = memchr(text, '\0', maxlen);
  33         return last ? (size_t) (last - text) : maxlen;
  34 }
  35 #define strnlen rep_strnlen
  36 #endif
  37
  38 #define bytehex(x) (((x)<0xa)?('0'+(x)):('a'-0xa+(x)))
  39
  40 static PyObject *tree_entry_cls;
  41 static PyObject *object_format_exception_cls;
  42
  43 static PyObject *sha_to_pyhex(const unsigned char *sha)
  44 {
  45         char hexsha[41];
  46         int i;
  47         for (i = 0; i < 20; i++) {
  48                 hexsha[i*2] = bytehex((sha[i] & 0xF0) >> 4);
  49                 hexsha[i*2+1] = bytehex(sha[i] & 0x0F);
  50         }
  51
  52         return PyString_FromStringAndSize(hexsha, 40);
  53 }
  54
  55 static PyObject *py_parse_tree(PyObject *self, PyObject *args, PyObject *kw)
  56 {
  57         char *text, *start, *end;
  58         int len, namelen, strict;
  59         PyObject *ret, *item, *name, *py_strict = NULL;
  60         static char *kwlist[] = {"text", "strict", NULL};
  61
  62         if (!PyArg_ParseTupleAndKeywords(args, kw, "s#|O", kwlist,
  63                                          &text, &len, &py_strict))
  64                 return NULL;
  65
  66
  67         strict = py_strict ?  PyObject_IsTrue(py_strict) : 0;
  68
  69         /* TODO: currently this returns a list; if memory usage is a concern,
  70          * consider rewriting as a custom iterator object */
  71         ret = PyList_New(0);
  72
  73         if (ret == NULL) {
  74                 return NULL;
  75         }
  76
  77         start = text;
  78         end = text + len;
  79
  80         while (text < end) {
  81                 long mode;
  82                 if (strict && text[0] == '0') {
  83                         PyErr_SetString(object_format_exception_cls,
  84                                         "Illegal leading zero on mode");
  85                         Py_DECREF(ret);
  86                         return NULL;
  87                 }
  88
  89                 mode = strtol(text, &text, 8);
  90
  91                 if (*text != ' ') {
  92                         PyErr_SetString(PyExc_ValueError, "Expected space");
  93                         Py_DECREF(ret);
  94                         return NULL;
  95                 }
  96
  97                 text++;
  98
  99                 namelen = strnlen(text, len - (text - start));
 100
 101                 name = PyString_FromStringAndSize(text, namelen);
 102                 if (name == NULL) {
 103                         Py_DECREF(ret);
 104                         return NULL;
 105                 }
 106
 107                 if (text + namelen + 20 >= end) {
 108                         PyErr_SetString(PyExc_ValueError, "SHA truncated");
 109                         Py_DECREF(ret);
 110                         Py_DECREF(name);
 111                         return NULL;
 112                 }
 113
 114                 item = Py_BuildValue("(NlN)", name, mode,
 115                                      sha_to_pyhex((unsigned char *)text+namelen+1));
 116                 if (item == NULL) {
 117                         Py_DECREF(ret);
 118                         Py_DECREF(name);
 119                         return NULL;
 120                 }
 121                 if (PyList_Append(ret, item) == -1) {
 122                         Py_DECREF(ret);
 123                         Py_DECREF(item);
 124                         return NULL;
 125                 }
 126                 Py_DECREF(item);
 127
 128                 text += namelen+21;
 129         }
 130
 131         return ret;
 132 }
 133
 134 struct tree_item {
 135         const char *name;
 136         int mode;
 137         PyObject *tuple;
 138 };
 139
 140 int cmp_tree_item(const void *_a, const void *_b)
 141 {
 142         const struct tree_item *a = _a, *b = _b;
 143         const char *remain_a, *remain_b;
 144         int ret, common;
 145         if (strlen(a->name) > strlen(b->name)) {
 146                 common = strlen(b->name);
 147                 remain_a = a->name + common;
 148                 remain_b = (S_ISDIR(b->mode)?"/":"");
 149         } else if (strlen(b->name) > strlen(a->name)) {
 150                 common = strlen(a->name);
 151                 remain_a = (S_ISDIR(a->mode)?"/":"");
 152                 remain_b = b->name + common;
 153         } else { /* strlen(a->name) == strlen(b->name) */
 154                 common = 0;
 155                 remain_a = a->name;
 156                 remain_b = b->name;
 157         }
 158         ret = strncmp(a->name, b->name, common);
 159         if (ret != 0)
 160                 return ret;
 161         return strcmp(remain_a, remain_b);
 162 }
 163
 164 int cmp_tree_item_name_order(const void *_a, const void *_b) {
 165         const struct tree_item *a = _a, *b = _b;
 166         return strcmp(a->name, b->name);
 167 }
 168
 169 static PyObject *py_sorted_tree_items(PyObject *self, PyObject *args)
 170 {
 171         struct tree_item *qsort_entries = NULL;
 172         int name_order, num_entries, n = 0, i;
 173         PyObject *entries, *py_name_order, *ret, *key, *value, *py_mode, *py_sha;
 174         Py_ssize_t pos = 0;
 175         int (*cmp)(const void *, const void *);
 176
 177         if (!PyArg_ParseTuple(args, "OO", &entries, &py_name_order))
 178                 goto error;
 179
 180         if (!PyDict_Check(entries)) {
 181                 PyErr_SetString(PyExc_TypeError, "Argument not a dictionary");
 182                 goto error;
 183         }
 184
 185         name_order = PyObject_IsTrue(py_name_order);
 186         if (name_order == -1)
 187                 goto error;
 188         cmp = name_order ? cmp_tree_item_name_order : cmp_tree_item;
 189
 190         num_entries = PyDict_Size(entries);
 191         if (PyErr_Occurred())
 192                 goto error;
 193         qsort_entries = PyMem_New(struct tree_item, num_entries);
 194         if (!qsort_entries) {
 195                 PyErr_NoMemory();
 196                 goto error;
 197         }
 198
 199         while (PyDict_Next(entries, &pos, &key, &value)) {
 200                 if (!PyString_Check(key)) {
 201                         PyErr_SetString(PyExc_TypeError, "Name is not a string");
 202                         goto error;
 203                 }
 204
 205                 if (PyTuple_Size(value) != 2) {
 206                         PyErr_SetString(PyExc_ValueError, "Tuple has invalid size");
 207                         goto error;
 208                 }
 209
 210                 py_mode = PyTuple_GET_ITEM(value, 0);
 211                 if (!PyInt_Check(py_mode)) {
 212                         PyErr_SetString(PyExc_TypeError, "Mode is not an integral type");
 213                         goto error;
 214                 }
 215
 216                 py_sha = PyTuple_GET_ITEM(value, 1);
 217                 if (!PyString_Check(py_sha)) {
 218                         PyErr_SetString(PyExc_TypeError, "SHA is not a string");
 219                         goto error;
 220                 }
 221                 qsort_entries[n].name = PyString_AS_STRING(key);
 222                 qsort_entries[n].mode = PyInt_AS_LONG(py_mode);
 223
 224                 qsort_entries[n].tuple = PyObject_CallFunctionObjArgs(
 225                                 tree_entry_cls, key, py_mode, py_sha, NULL);
 226                 if (qsort_entries[n].tuple == NULL)
 227                         goto error;
 228                 n++;
 229         }
 230
 231         qsort(qsort_entries, num_entries, sizeof(struct tree_item), cmp);
 232
 233         ret = PyList_New(num_entries);
 234         if (ret == NULL) {
 235                 PyErr_NoMemory();
 236                 goto error;
 237         }
 238
 239         for (i = 0; i < num_entries; i++) {
 240                 PyList_SET_ITEM(ret, i, qsort_entries[i].tuple);
 241         }
 242         PyMem_Free(qsort_entries);
 243         return ret;
 244
 245 error:
 246         for (i = 0; i < n; i++) {
 247                 Py_XDECREF(qsort_entries[i].tuple);
 248         }
 249         PyMem_Free(qsort_entries);
 250         return NULL;
 251 }
 252
 253 static PyMethodDef py_objects_methods[] = {
 254         { "parse_tree", (PyCFunction)py_parse_tree, METH_VARARGS | METH_KEYWORDS,
 255           NULL },
 256         { "sorted_tree_items", py_sorted_tree_items, METH_VARARGS, NULL },
 257         { NULL, NULL, 0, NULL }
 258 };
 259
 260 PyMODINIT_FUNC
 261 init_objects(void)
 262 {
 263         PyObject *m, *objects_mod, *errors_mod;
 264
 265         m = Py_InitModule3("_objects", py_objects_methods, NULL);
 266         if (m == NULL)
 267                 return;
 268
 269
 270         errors_mod = PyImport_ImportModule("dulwich.errors");
 271         if (errors_mod == NULL)
 272                 return;
 273
 274         object_format_exception_cls = PyObject_GetAttrString(
 275                 errors_mod, "ObjectFormatException");
 276         Py_DECREF(errors_mod);
 277         if (object_format_exception_cls == NULL)
 278                 return;
 279
 280         /* This is a circular import but should be safe since this module is
 281          * imported at at the very bottom of objects.py. */
 282         objects_mod = PyImport_ImportModule("dulwich.objects");
 283         if (objects_mod == NULL)
 284                 return;
 285
 286         tree_entry_cls = PyObject_GetAttrString(objects_mod, "TreeEntry");
 287         Py_DECREF(objects_mod);
 288         if (tree_entry_cls == NULL)
 289                 return;
 290 }