/* * diffhelpers.c - helper routines for mpatch * * Copyright 2007 Chris Mason <chris.mason@oracle.com> * * This software may be used and distributed according to the terms * of the GNU General Public License v2, incorporated herein by reference. */ #include <Python.h>#include <stdlib.h>#include <string.h> static char diffhelpers_doc[] = "Efficient diff parsing";static PyObject *diffhelpers_Error;  /* fixup the last lines of a and b when the patch has no newline at eof */static void _fix_newline(PyObject *hunk, PyObject *a, PyObject *b){	int hunksz = PyList_Size(hunk);	PyObject *s = PyList_GET_ITEM(hunk, hunksz-1);	char *l = PyString_AS_STRING(s);	int sz = PyString_GET_SIZE(s);	int alen = PyList_Size(a);	int blen = PyList_Size(b);	char c = l[0]; 	PyObject *hline = PyString_FromStringAndSize(l, sz-1);	if (c == ' ' || c == '+') {		PyObject *rline = PyString_FromStringAndSize(l+1, sz-2);		PyList_SetItem(b, blen-1, rline);	}	if (c == ' ' || c == '-') {		Py_INCREF(hline);		PyList_SetItem(a, alen-1, hline);	}	PyList_SetItem(hunk, hunksz-1, hline);} /* python callable form of _fix_newline */static PyObject *fix_newline(PyObject *self, PyObject *args){	PyObject *hunk, *a, *b;	if (!PyArg_ParseTuple(args, "OOO", &hunk, &a, &b))		return NULL;	_fix_newline(hunk, a, b);	return Py_BuildValue("l", 0);} /* * read lines from fp into the hunk.  The hunk is parsed into two arrays * a and b.  a gets the old state of the text, b gets the new state * The control char from the hunk is saved when inserting into a, but not b * (for performance while deleting files) */static PyObject *addlines(PyObject *self, PyObject *args){ 	PyObject *fp, *hunk, *a, *b, *x;	int i;	int lena, lenb;	int num;	int todoa, todob;	char *s, c;	PyObject *l;	if (!PyArg_ParseTuple(args, "OOiiOO", &fp, &hunk, &lena, &lenb, &a, &b))		return NULL; 	while(1) {		todoa = lena - PyList_Size(a);		todob = lenb - PyList_Size(b);		num = todoa > todob ? todoa : todob;		if (num == 0)		    break;		for (i = 0 ; i < num ; i++) {			x = PyFile_GetLine(fp, 0);			s = PyString_AS_STRING(x);			c = *s;			if (strcmp(s, "\\ No newline at end of file\n") == 0) {				_fix_newline(hunk, a, b);				continue;			}			if (c == '\n') {				/* Some patches may be missing the control char				 * on empty lines. Supply a leading space. */				Py_DECREF(x);				x = PyString_FromString(" \n");			}			PyList_Append(hunk, x);			if (c == '+') {				l = PyString_FromString(s + 1);				PyList_Append(b, l);				Py_DECREF(l);			} else if (c == '-') {				PyList_Append(a, x);			} else {				l = PyString_FromString(s + 1);				PyList_Append(b, l);				Py_DECREF(l);				PyList_Append(a, x);			}			Py_DECREF(x);		}	}	return Py_BuildValue("l", 0);} /* * compare the lines in a with the lines in b.  a is assumed to have * a control char at the start of each line, this char is ignored in the * compare */static PyObject *testhunk(PyObject *self, PyObject *args){ 	PyObject *a, *b;	long bstart;	int alen, blen;	int i;	char *sa, *sb; 	if (!PyArg_ParseTuple(args, "OOl", &a, &b, &bstart))		return NULL;	alen = PyList_Size(a);	blen = PyList_Size(b);	if (alen > blen - bstart) {		return Py_BuildValue("l", -1);	}	for (i = 0 ; i < alen ; i++) {		sa = PyString_AS_STRING(PyList_GET_ITEM(a, i));		sb = PyString_AS_STRING(PyList_GET_ITEM(b, i + bstart));		if (strcmp(sa+1, sb) != 0)			return Py_BuildValue("l", -1);	}	return Py_BuildValue("l", 0);} static PyMethodDef methods[] = {	{"addlines", addlines, METH_VARARGS, "add lines to a hunk\n"},	{"fix_newline", fix_newline, METH_VARARGS, "fixup newline counters\n"},	{"testhunk", testhunk, METH_VARARGS, "test lines in a hunk\n"},	{NULL, NULL}}; PyMODINIT_FUNCinitdiffhelpers(void){	Py_InitModule3("diffhelpers", methods, diffhelpers_doc);	diffhelpers_Error = PyErr_NewException("diffhelpers.diffhelpersError",	                                        NULL, NULL);}