ref: 0e6e44b06400e320145eb5115edce054cfd26d1f
dir: /sys/lib/python/mercurial/diffhelpers.c/
/*
* 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);
}