Mercurial > hg
view mercurial/bdiff_module.c @ 31586:df82f375fa00
checkheads: extract obsolete post processing in its own function
The checkheads function is long and complex, extract that logic in a subfunction
is win in itself. As the comment in the code says, this postprocessing is
currently very basic and either misbehave or fails to detect valid push in many
cases. My deeper motive for this extraction is to be make it easier to provide
extensive testing of this case and strategy to cover them. Final test and logic
will makes it to core once done.
author | Pierre-Yves David <pierre-yves.david@ens-lyon.org> |
---|---|
date | Tue, 21 Mar 2017 23:30:13 +0100 |
parents | 08ecec297521 |
children | 4195b84940e9 |
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/* bdiff.c - efficient binary diff extension for Mercurial Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> This software may be used and distributed according to the terms of the GNU General Public License, incorporated herein by reference. Based roughly on Python difflib */ #define PY_SSIZE_T_CLEAN #include <Python.h> #include <stdlib.h> #include <string.h> #include <limits.h> #include "bdiff.h" #include "bitmanipulation.h" #include "util.h" static PyObject *blocks(PyObject *self, PyObject *args) { PyObject *sa, *sb, *rl = NULL, *m; struct bdiff_line *a, *b; struct bdiff_hunk l, *h; int an, bn, count, pos = 0; l.next = NULL; if (!PyArg_ParseTuple(args, "SS:bdiff", &sa, &sb)) return NULL; an = bdiff_splitlines(PyBytes_AsString(sa), PyBytes_Size(sa), &a); bn = bdiff_splitlines(PyBytes_AsString(sb), PyBytes_Size(sb), &b); if (!a || !b) goto nomem; count = bdiff_diff(a, an, b, bn, &l); if (count < 0) goto nomem; rl = PyList_New(count); if (!rl) goto nomem; for (h = l.next; h; h = h->next) { m = Py_BuildValue("iiii", h->a1, h->a2, h->b1, h->b2); PyList_SetItem(rl, pos, m); pos++; } nomem: free(a); free(b); bdiff_freehunks(l.next); return rl ? rl : PyErr_NoMemory(); } static PyObject *bdiff(PyObject *self, PyObject *args) { char *sa, *sb, *rb, *ia, *ib; PyObject *result = NULL; struct bdiff_line *al, *bl; struct bdiff_hunk l, *h; int an, bn, count; Py_ssize_t len = 0, la, lb, li = 0, lcommon = 0, lmax; PyThreadState *_save; l.next = NULL; if (!PyArg_ParseTuple(args, "s#s#:bdiff", &sa, &la, &sb, &lb)) return NULL; if (la > UINT_MAX || lb > UINT_MAX) { PyErr_SetString(PyExc_ValueError, "bdiff inputs too large"); return NULL; } _save = PyEval_SaveThread(); lmax = la > lb ? lb : la; for (ia = sa, ib = sb; li < lmax && *ia == *ib; ++li, ++ia, ++ib) if (*ia == '\n') lcommon = li + 1; /* we can almost add: if (li == lmax) lcommon = li; */ an = bdiff_splitlines(sa + lcommon, la - lcommon, &al); bn = bdiff_splitlines(sb + lcommon, lb - lcommon, &bl); if (!al || !bl) goto nomem; count = bdiff_diff(al, an, bl, bn, &l); if (count < 0) goto nomem; /* calculate length of output */ la = lb = 0; for (h = l.next; h; h = h->next) { if (h->a1 != la || h->b1 != lb) len += 12 + bl[h->b1].l - bl[lb].l; la = h->a2; lb = h->b2; } PyEval_RestoreThread(_save); _save = NULL; result = PyBytes_FromStringAndSize(NULL, len); if (!result) goto nomem; /* build binary patch */ rb = PyBytes_AsString(result); la = lb = 0; for (h = l.next; h; h = h->next) { if (h->a1 != la || h->b1 != lb) { len = bl[h->b1].l - bl[lb].l; putbe32((uint32_t)(al[la].l + lcommon - al->l), rb); putbe32((uint32_t)(al[h->a1].l + lcommon - al->l), rb + 4); putbe32((uint32_t)len, rb + 8); memcpy(rb + 12, bl[lb].l, len); rb += 12 + len; } la = h->a2; lb = h->b2; } nomem: if (_save) PyEval_RestoreThread(_save); free(al); free(bl); bdiff_freehunks(l.next); return result ? result : PyErr_NoMemory(); } /* * If allws != 0, remove all whitespace (' ', \t and \r). Otherwise, * reduce whitespace sequences to a single space and trim remaining whitespace * from end of lines. */ static PyObject *fixws(PyObject *self, PyObject *args) { PyObject *s, *result = NULL; char allws, c; const char *r; Py_ssize_t i, rlen, wlen = 0; char *w; if (!PyArg_ParseTuple(args, "Sb:fixws", &s, &allws)) return NULL; r = PyBytes_AsString(s); rlen = PyBytes_Size(s); w = (char *)PyMem_Malloc(rlen ? rlen : 1); if (!w) goto nomem; for (i = 0; i != rlen; i++) { c = r[i]; if (c == ' ' || c == '\t' || c == '\r') { if (!allws && (wlen == 0 || w[wlen - 1] != ' ')) w[wlen++] = ' '; } else if (c == '\n' && !allws && wlen > 0 && w[wlen - 1] == ' ') { w[wlen - 1] = '\n'; } else { w[wlen++] = c; } } result = PyBytes_FromStringAndSize(w, wlen); nomem: PyMem_Free(w); return result ? result : PyErr_NoMemory(); } 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"}, {NULL, NULL} }; #ifdef IS_PY3K static struct PyModuleDef bdiff_module = { PyModuleDef_HEAD_INIT, "bdiff", mdiff_doc, -1, methods }; PyMODINIT_FUNC PyInit_bdiff(void) { return PyModule_Create(&bdiff_module); } #else PyMODINIT_FUNC initbdiff(void) { Py_InitModule3("bdiff", methods, mdiff_doc); } #endif