comparison mercurial/cext/bdiff.c @ 36675:430fdb717549

bdiff: add a xdiffblocks method

This is similar to `bdiff.blocks`, but uses xdiff as the backend.

The indent heuristic is turned on by default since it has little overhead
and improves diff quality significantly.

Differential Revision: https://phab.mercurial-scm.org/D2602

36674:c420792217c8

#include <stdlib.h>
#include <string.h>

#include "bdiff.h"
#include "bitmanipulation.h"
#include "util.h"

static PyObject *blocks(PyObject *self, PyObject *args)
{
	PyObject *sa, *sb, *rl = NULL, *m;

abort:
	Py_XDECREF(result);
	return NULL;
}

static char mdiff_doc[] = "Efficient binary diff.";

static PyMethodDef methods[] = {
    {"bdiff", bdiff, METH_VARARGS, "calculate a binary diff\n"},
    {"blocks", blocks, METH_VARARGS, "find a list of matching lines\n"},
    {"fixws", fixws, METH_VARARGS, "normalize diff whitespaces\n"},
    {"splitnewlines", splitnewlines, METH_VARARGS,
     "like str.splitlines, but only split on newlines\n"},
    {NULL, NULL},
};

static const int version = 2;

#ifdef IS_PY3K
static struct PyModuleDef bdiff_module = {
    PyModuleDef_HEAD_INIT, "bdiff", mdiff_doc, -1, methods,
};

36675:430fdb717549

#include <stdlib.h>
#include <string.h>

#include "bdiff.h"
#include "bitmanipulation.h"
#include "thirdparty/xdiff/xdiff.h"
#include "util.h"

static PyObject *blocks(PyObject *self, PyObject *args)
{
	PyObject *sa, *sb, *rl = NULL, *m;

abort:
	Py_XDECREF(result);
	return NULL;
}

static int hunk_consumer(long a1, long a2, long b1, long b2, void *priv)
{
	PyObject *rl = (PyObject *)priv;
	PyObject *m = Py_BuildValue("llll", a1, a2, b1, b2);
	if (!m)
		return -1;
	if (PyList_Append(rl, m) != 0) {
		Py_DECREF(m);
		return -1;
	}
	return 0;
}

static PyObject *xdiffblocks(PyObject *self, PyObject *args)
{
	Py_ssize_t la, lb;
	mmfile_t a, b;
	PyObject *rl;

	xpparam_t xpp = {
	    XDF_INDENT_HEURISTIC, /* flags */
	    NULL,                 /* anchors */
	    0,                    /* anchors_nr */
	};
	xdemitconf_t xecfg = {
	    0,                  /* ctxlen */
	    0,                  /* interhunkctxlen */
	    XDL_EMIT_BDIFFHUNK, /* flags */
	    NULL,               /* find_func */
	    NULL,               /* find_func_priv */
	    hunk_consumer,      /* hunk_consume_func */
	};
	xdemitcb_t ecb = {
	    NULL, /* priv */
	    NULL, /* outf */
	};

	if (!PyArg_ParseTuple(args, PY23("s#s#", "y#y#"), &a.ptr, &la, &b.ptr,
	                      &lb))
		return NULL;

	a.size = la;
	b.size = lb;

	rl = PyList_New(0);
	if (!rl)
		return PyErr_NoMemory();

	ecb.priv = rl;

	if (xdl_diff(&a, &b, &xpp, &xecfg, &ecb) != 0) {
		Py_DECREF(rl);
		return PyErr_NoMemory();
	}

	return rl;
}

static char mdiff_doc[] = "Efficient binary diff.";

static PyMethodDef methods[] = {
    {"bdiff", bdiff, METH_VARARGS, "calculate a binary diff\n"},
    {"blocks", blocks, METH_VARARGS, "find a list of matching lines\n"},
    {"fixws", fixws, METH_VARARGS, "normalize diff whitespaces\n"},
    {"splitnewlines", splitnewlines, METH_VARARGS,
     "like str.splitlines, but only split on newlines\n"},
    {"xdiffblocks", xdiffblocks, METH_VARARGS,
     "find a list of matching lines using xdiff algorithm\n"},
    {NULL, NULL},
};

static const int version = 3;

#ifdef IS_PY3K
static struct PyModuleDef bdiff_module = {
    PyModuleDef_HEAD_INIT, "bdiff", mdiff_doc, -1, methods,
};