Mercurial > hg
view mercurial/cext/mpatch.c @ 42522:d29db0a0c4eb
update: fix spurious unclean status bug shown by previous commit
The crux of the problem is:
- the dirstate is corrupted (the sizes/dates are assigned to the wrong files)
- because when worker.worker is used with a return value (batchget in
merge.py here), the return value when worker.worker effectively parallelizes
is permuted
- this is because worker.worker's partition of input and combination of output
values are not inverses of one another: it split [1,2,3,4,5,6] into
[[1,3,5],[2,4,6]], but combines that into [1,3,5,2,4,6].
Given that worker.worker doesn't call its function argument on contiguous
chunks on the input arguments, sticking with lists means we'd need to
know the relation between the inputs of worker.worker function argument
(for instance, requiring that every input element is mapped to exactly
one output element). It seems better to instead switch return values to
dicts, which can combined reliably with a straighforward restriction.
Differential Revision: https://phab.mercurial-scm.org/D6581
author | Valentin Gatien-Baron <valentin.gatienbaron@gmail.com> |
---|---|
date | Thu, 27 Jun 2019 11:39:35 +0200 |
parents | 763b45bc4483 |
children | d4ba4d51f85f |
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line source
/* mpatch.c - efficient binary patching for Mercurial This implements a patch algorithm that's O(m + nlog n) where m is the size of the output and n is the number of patches. Given a list of binary patches, it unpacks each into a hunk list, then combines the hunk lists with a treewise recursion to form a single hunk list. This hunk list is then applied to the original text. The text (or binary) fragments are copied directly from their source Python objects into a preallocated output string to avoid the allocation of intermediate Python objects. Working memory is about 2x the total number of hunks. 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. */ #define PY_SSIZE_T_CLEAN #include <Python.h> #include <stdlib.h> #include <string.h> #include "bitmanipulation.h" #include "compat.h" #include "mpatch.h" #include "util.h" static char mpatch_doc[] = "Efficient binary patching."; static PyObject *mpatch_Error; static void setpyerr(int r) { switch (r) { case MPATCH_ERR_NO_MEM: PyErr_NoMemory(); break; case MPATCH_ERR_CANNOT_BE_DECODED: PyErr_SetString(mpatch_Error, "patch cannot be decoded"); break; case MPATCH_ERR_INVALID_PATCH: PyErr_SetString(mpatch_Error, "invalid patch"); break; } } struct mpatch_flist *cpygetitem(void *bins, ssize_t pos) { Py_buffer buffer; struct mpatch_flist *res = NULL; int r; PyObject *tmp = PyList_GetItem((PyObject *)bins, pos); if (!tmp) { return NULL; } if (PyObject_GetBuffer(tmp, &buffer, PyBUF_CONTIG_RO)) { return NULL; } if ((r = mpatch_decode(buffer.buf, buffer.len, &res)) < 0) { if (!PyErr_Occurred()) { setpyerr(r); } res = NULL; } PyBuffer_Release(&buffer); return res; } static PyObject *patches(PyObject *self, PyObject *args) { PyObject *text, *bins, *result; struct mpatch_flist *patch; Py_buffer buffer; int r = 0; char *out; Py_ssize_t len, outlen; if (!PyArg_ParseTuple(args, "OO:mpatch", &text, &bins)) { return NULL; } len = PyList_Size(bins); if (!len) { /* nothing to do */ Py_INCREF(text); return text; } if (PyObject_GetBuffer(text, &buffer, PyBUF_CONTIG_RO)) { return NULL; } patch = mpatch_fold(bins, cpygetitem, 0, len); if (!patch) { /* error already set or memory error */ if (!PyErr_Occurred()) { PyErr_NoMemory(); } result = NULL; goto cleanup; } outlen = mpatch_calcsize(buffer.len, patch); if (outlen < 0) { r = (int)outlen; result = NULL; goto cleanup; } result = PyBytes_FromStringAndSize(NULL, outlen); if (!result) { result = NULL; goto cleanup; } out = PyBytes_AsString(result); /* clang-format off */ { Py_BEGIN_ALLOW_THREADS r = mpatch_apply(out, buffer.buf, buffer.len, patch); Py_END_ALLOW_THREADS } /* clang-format on */ if (r < 0) { Py_DECREF(result); result = NULL; } cleanup: mpatch_lfree(patch); PyBuffer_Release(&buffer); if (!result && !PyErr_Occurred()) { setpyerr(r); } return result; } /* calculate size of a patched file directly */ static PyObject *patchedsize(PyObject *self, PyObject *args) { long orig, start, end, len, outlen = 0, last = 0, pos = 0; Py_ssize_t patchlen; char *bin; if (!PyArg_ParseTuple(args, PY23("ls#", "ly#"), &orig, &bin, &patchlen)) { return NULL; } while (pos >= 0 && pos < patchlen) { start = getbe32(bin + pos); end = getbe32(bin + pos + 4); len = getbe32(bin + pos + 8); if (start > end) { break; /* sanity check */ } pos += 12 + len; outlen += start - last; last = end; outlen += len; } if (pos != patchlen) { if (!PyErr_Occurred()) { PyErr_SetString(mpatch_Error, "patch cannot be decoded"); } return NULL; } outlen += orig - last; return Py_BuildValue("l", outlen); } static PyMethodDef methods[] = { {"patches", patches, METH_VARARGS, "apply a series of patches\n"}, {"patchedsize", patchedsize, METH_VARARGS, "calculed patched size\n"}, {NULL, NULL}, }; static const int version = 1; #ifdef IS_PY3K static struct PyModuleDef mpatch_module = { PyModuleDef_HEAD_INIT, "mpatch", mpatch_doc, -1, methods, }; PyMODINIT_FUNC PyInit_mpatch(void) { PyObject *m; m = PyModule_Create(&mpatch_module); if (m == NULL) return NULL; mpatch_Error = PyErr_NewException("mercurial.cext.mpatch.mpatchError", NULL, NULL); Py_INCREF(mpatch_Error); PyModule_AddObject(m, "mpatchError", mpatch_Error); PyModule_AddIntConstant(m, "version", version); return m; } #else PyMODINIT_FUNC initmpatch(void) { PyObject *m; m = Py_InitModule3("mpatch", methods, mpatch_doc); mpatch_Error = PyErr_NewException("mercurial.cext.mpatch.mpatchError", NULL, NULL); PyModule_AddIntConstant(m, "version", version); } #endif