Mercurial > hg
view mercurial/diffhelpers.c @ 26478:a3f7e5461dbd
util.chunkbuffer: special case reading everything
The new code results in simpler logic within the while loop. It is also
faster since we avoid performing operations on the queue and buf
collections. However, there shouldn't be any super hot loops for this
since the whole point of chunkbuffer is to avoid reading large amounts
of data at once. This does, however, make it easier to optimize
chunkbuffer in a subsequent patch.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 05 Oct 2015 16:28:12 -0700 |
parents | f1c127df7c4f |
children | 2f51f4c535d2 |
line wrap: on
line source
/* * 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> #include "util.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) { Py_ssize_t hunksz = PyList_Size(hunk); PyObject *s = PyList_GET_ITEM(hunk, hunksz-1); char *l = PyBytes_AsString(s); Py_ssize_t alen = PyList_Size(a); Py_ssize_t blen = PyList_Size(b); char c = l[0]; PyObject *hline; Py_ssize_t sz = PyBytes_GET_SIZE(s); if (sz > 1 && l[sz-2] == '\r') /* tolerate CRLF in last line */ sz -= 1; hline = PyBytes_FromStringAndSize(l, sz-1); if (!hline) { return; } if (c == ' ' || c == '+') { PyObject *rline = PyBytes_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); } #if (PY_VERSION_HEX < 0x02050000) static const char *addlines_format = "OOiiOO"; #else static const char *addlines_format = "OOnnOO"; #endif /* * 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; Py_ssize_t i; Py_ssize_t lena, lenb; Py_ssize_t num; Py_ssize_t todoa, todob; char *s, c; PyObject *l; if (!PyArg_ParseTuple(args, addlines_format, &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 = PyBytes_AsString(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 = PyBytes_FromString(" \n"); } PyList_Append(hunk, x); if (c == '+') { l = PyBytes_FromString(s + 1); PyList_Append(b, l); Py_DECREF(l); } else if (c == '-') { PyList_Append(a, x); } else { l = PyBytes_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; Py_ssize_t alen, blen; Py_ssize_t 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 || bstart < 0) { return Py_BuildValue("l", -1); } for (i = 0; i < alen; i++) { sa = PyBytes_AsString(PyList_GET_ITEM(a, i)); sb = PyBytes_AsString(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} }; #ifdef IS_PY3K static struct PyModuleDef diffhelpers_module = { PyModuleDef_HEAD_INIT, "diffhelpers", diffhelpers_doc, -1, methods }; PyMODINIT_FUNC PyInit_diffhelpers(void) { PyObject *m; m = PyModule_Create(&diffhelpers_module); if (m == NULL) return NULL; diffhelpers_Error = PyErr_NewException("diffhelpers.diffhelpersError", NULL, NULL); Py_INCREF(diffhelpers_Error); PyModule_AddObject(m, "diffhelpersError", diffhelpers_Error); return m; } #else PyMODINIT_FUNC initdiffhelpers(void) { Py_InitModule3("diffhelpers", methods, diffhelpers_doc); diffhelpers_Error = PyErr_NewException("diffhelpers.diffhelpersError", NULL, NULL); } #endif