+
−/*
+
− * 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_FUNC
+
−initdiffhelpers(void)
+
−{
+
−	Py_InitModule3("diffhelpers", methods, diffhelpers_doc);
+
−	diffhelpers_Error = PyErr_NewException("diffhelpers.diffhelpersError",
+
−	                                        NULL, NULL);
+
−}
+
−