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1 /* |
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2 * diffhelpers.c - helper routines for mpatch |
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3 * |
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4 * Copyright 2007 Chris Mason <chris.mason@oracle.com> |
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5 * |
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6 * This software may be used and distributed according to the terms |
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7 * of the GNU General Public License v2, incorporated herein by reference. |
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8 */ |
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9 |
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10 #include <Python.h> |
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11 #include <stdlib.h> |
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12 #include <string.h> |
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13 |
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14 static char diffhelpers_doc[] = "Efficient diff parsing"; |
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15 static PyObject *diffhelpers_Error; |
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16 |
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17 |
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18 /* fixup the last lines of a and b when the patch has no newline at eof */ |
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19 static void _fix_newline(PyObject *hunk, PyObject *a, PyObject *b) |
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20 { |
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21 int hunksz = PyList_Size(hunk); |
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22 PyObject *s = PyList_GET_ITEM(hunk, hunksz-1); |
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23 char *l = PyString_AS_STRING(s); |
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24 int sz = PyString_GET_SIZE(s); |
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25 int alen = PyList_Size(a); |
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26 int blen = PyList_Size(b); |
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27 char c = l[0]; |
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28 |
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29 PyObject *hline = PyString_FromStringAndSize(l, sz-1); |
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30 if (c == ' ' || c == '+') { |
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31 PyObject *rline = PyString_FromStringAndSize(l+1, sz-2); |
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32 PyList_SetItem(b, blen-1, rline); |
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33 } |
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34 if (c == ' ' || c == '-') { |
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35 Py_INCREF(hline); |
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36 PyList_SetItem(a, alen-1, hline); |
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37 } |
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38 PyList_SetItem(hunk, hunksz-1, hline); |
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39 } |
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40 |
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41 /* python callable form of _fix_newline */ |
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42 static PyObject * |
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43 fix_newline(PyObject *self, PyObject *args) |
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44 { |
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45 PyObject *hunk, *a, *b; |
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46 if (!PyArg_ParseTuple(args, "OOO", &hunk, &a, &b)) |
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47 return NULL; |
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48 _fix_newline(hunk, a, b); |
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49 return Py_BuildValue("l", 0); |
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50 } |
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51 |
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52 /* |
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53 * read lines from fp into the hunk. The hunk is parsed into two arrays |
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54 * a and b. a gets the old state of the text, b gets the new state |
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55 * The control char from the hunk is saved when inserting into a, but not b |
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56 * (for performance while deleting files) |
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57 */ |
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58 static PyObject * |
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59 addlines(PyObject *self, PyObject *args) |
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60 { |
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61 |
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62 PyObject *fp, *hunk, *a, *b, *x; |
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63 int i; |
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64 int lena, lenb; |
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65 int num; |
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66 int todoa, todob; |
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67 char *s, c; |
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68 PyObject *l; |
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69 if (!PyArg_ParseTuple(args, "OOiiOO", &fp, &hunk, &lena, &lenb, &a, &b)) |
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70 return NULL; |
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71 |
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72 while(1) { |
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73 todoa = lena - PyList_Size(a); |
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74 todob = lenb - PyList_Size(b); |
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75 num = todoa > todob ? todoa : todob; |
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76 if (num == 0) |
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77 break; |
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78 for (i = 0 ; i < num ; i++) { |
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79 x = PyFile_GetLine(fp, 0); |
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80 s = PyString_AS_STRING(x); |
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81 c = *s; |
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82 if (strcmp(s, "\\ No newline at end of file\n") == 0) { |
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83 _fix_newline(hunk, a, b); |
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84 continue; |
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85 } |
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86 PyList_Append(hunk, x); |
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87 if (c == '+') { |
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88 l = PyString_FromString(s + 1); |
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89 PyList_Append(b, l); |
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90 Py_DECREF(l); |
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91 } else if (c == '-') { |
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92 PyList_Append(a, x); |
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93 } else { |
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94 l = PyString_FromString(s + 1); |
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95 PyList_Append(b, l); |
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96 Py_DECREF(l); |
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97 PyList_Append(a, x); |
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98 } |
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99 Py_DECREF(x); |
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100 } |
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101 } |
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102 return Py_BuildValue("l", 0); |
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103 } |
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104 |
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105 /* |
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106 * compare the lines in a with the lines in b. a is assumed to have |
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107 * a control char at the start of each line, this char is ignored in the |
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108 * compare |
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109 */ |
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110 static PyObject * |
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111 testhunk(PyObject *self, PyObject *args) |
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112 { |
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113 |
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114 PyObject *a, *b; |
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115 long bstart; |
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116 int alen, blen; |
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117 int i; |
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118 char *sa, *sb; |
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119 |
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120 if (!PyArg_ParseTuple(args, "OOl", &a, &b, &bstart)) |
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121 return NULL; |
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122 alen = PyList_Size(a); |
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123 blen = PyList_Size(b); |
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124 if (alen > blen - bstart) { |
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125 return Py_BuildValue("l", -1); |
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126 } |
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127 for (i = 0 ; i < alen ; i++) { |
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128 sa = PyString_AS_STRING(PyList_GET_ITEM(a, i)); |
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129 sb = PyString_AS_STRING(PyList_GET_ITEM(b, i + bstart)); |
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130 if (strcmp(sa+1, sb) != 0) |
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131 return Py_BuildValue("l", -1); |
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132 } |
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133 return Py_BuildValue("l", 0); |
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134 } |
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135 |
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136 static PyMethodDef methods[] = { |
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137 {"addlines", addlines, METH_VARARGS, "add lines to a hunk\n"}, |
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138 {"fix_newline", fix_newline, METH_VARARGS, "fixup newline counters\n"}, |
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139 {"testhunk", testhunk, METH_VARARGS, "test lines in a hunk\n"}, |
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140 {NULL, NULL} |
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141 }; |
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142 |
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143 PyMODINIT_FUNC |
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144 initdiffhelpers(void) |
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145 { |
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146 Py_InitModule3("diffhelpers", methods, diffhelpers_doc); |
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147 diffhelpers_Error = PyErr_NewException("diffhelpers.diffhelpersError", |
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148 NULL, NULL); |
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149 } |
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150 |