Mercurial > hg
view hgext/inotify/linux/_inotify.c @ 6239:39cfcef4f463
Add inotify extension
author | Bryan O'Sullivan <bos@serpentine.com> |
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date | Wed, 12 Mar 2008 15:30:11 -0700 |
parents | |
children | 7016f7fb8fe3 |
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/* * _inotify.c - Python extension interfacing to the Linux inotify subsystem * * Copyright 2006 Bryan O'Sullivan <bos@serpentine.com> * * This library is free software; you can redistribute it and/or * modify it under the terms of version 2.1 of the GNU Lesser General * Public License, incorporated herein by reference. */ #include <Python.h> #include <alloca.h> #include <sys/inotify.h> #include <stdint.h> #include <sys/ioctl.h> #include <unistd.h> static PyObject *init(PyObject *self, PyObject *args) { PyObject *ret = NULL; int fd = -1; if (!PyArg_ParseTuple(args, ":init")) goto bail; Py_BEGIN_ALLOW_THREADS fd = inotify_init(); Py_END_ALLOW_THREADS if (fd == -1) { PyErr_SetFromErrno(PyExc_OSError); goto bail; } ret = PyInt_FromLong(fd); if (ret == NULL) goto bail; goto done; bail: if (fd != -1) close(fd); Py_CLEAR(ret); done: return ret; } PyDoc_STRVAR( init_doc, "init() -> fd\n" "\n" "Initialise an inotify instance.\n" "Return a file descriptor associated with a new inotify event queue."); static PyObject *add_watch(PyObject *self, PyObject *args) { PyObject *ret = NULL; uint32_t mask; int wd = -1; char *path; int fd; if (!PyArg_ParseTuple(args, "isI:add_watch", &fd, &path, &mask)) goto bail; Py_BEGIN_ALLOW_THREADS wd = inotify_add_watch(fd, path, mask); Py_END_ALLOW_THREADS if (wd == -1) { PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto bail; } ret = PyInt_FromLong(wd); if (ret == NULL) goto bail; goto done; bail: if (wd != -1) inotify_rm_watch(fd, wd); Py_CLEAR(ret); done: return ret; } PyDoc_STRVAR( add_watch_doc, "add_watch(fd, path, mask) -> wd\n" "\n" "Add a watch to an inotify instance, or modify an existing watch.\n" "\n" " fd: file descriptor returned by init()\n" " path: path to watch\n" " mask: mask of events to watch for\n" "\n" "Return a unique numeric watch descriptor for the inotify instance\n" "mapped by the file descriptor."); static PyObject *remove_watch(PyObject *self, PyObject *args) { PyObject *ret = NULL; uint32_t wd; int fd; int r; if (!PyArg_ParseTuple(args, "iI:remove_watch", &fd, &wd)) goto bail; Py_BEGIN_ALLOW_THREADS r = inotify_rm_watch(fd, wd); Py_END_ALLOW_THREADS if (r == -1) { PyErr_SetFromErrno(PyExc_OSError); goto bail; } Py_INCREF(Py_None); goto done; bail: Py_CLEAR(ret); done: return ret; } PyDoc_STRVAR( remove_watch_doc, "remove_watch(fd, wd)\n" "\n" " fd: file descriptor returned by init()\n" " wd: watch descriptor returned by add_watch()\n" "\n" "Remove a watch associated with the watch descriptor wd from the\n" "inotify instance associated with the file descriptor fd.\n" "\n" "Removing a watch causes an IN_IGNORED event to be generated for this\n" "watch descriptor."); #define bit_name(x) {x, #x} static struct { int bit; const char *name; PyObject *pyname; } bit_names[] = { bit_name(IN_ACCESS), bit_name(IN_MODIFY), bit_name(IN_ATTRIB), bit_name(IN_CLOSE_WRITE), bit_name(IN_CLOSE_NOWRITE), bit_name(IN_OPEN), bit_name(IN_MOVED_FROM), bit_name(IN_MOVED_TO), bit_name(IN_CREATE), bit_name(IN_DELETE), bit_name(IN_DELETE_SELF), bit_name(IN_MOVE_SELF), bit_name(IN_UNMOUNT), bit_name(IN_Q_OVERFLOW), bit_name(IN_IGNORED), bit_name(IN_ONLYDIR), bit_name(IN_DONT_FOLLOW), bit_name(IN_MASK_ADD), bit_name(IN_ISDIR), bit_name(IN_ONESHOT), {0} }; static PyObject *decode_mask(int mask) { PyObject *ret = PyList_New(0); int i; if (ret == NULL) goto bail; for (i = 0; bit_names[i].bit; i++) { if (mask & bit_names[i].bit) { if (bit_names[i].pyname == NULL) { bit_names[i].pyname = PyString_FromString(bit_names[i].name); if (bit_names[i].pyname == NULL) goto bail; } Py_INCREF(bit_names[i].pyname); if (PyList_Append(ret, bit_names[i].pyname) == -1) goto bail; } } goto done; bail: Py_CLEAR(ret); done: return ret; } static PyObject *pydecode_mask(PyObject *self, PyObject *args) { int mask; if (!PyArg_ParseTuple(args, "i:decode_mask", &mask)) return NULL; return decode_mask(mask); } PyDoc_STRVAR( decode_mask_doc, "decode_mask(mask) -> list_of_strings\n" "\n" "Decode an inotify mask value into a list of strings that give the\n" "name of each bit set in the mask."); static char doc[] = "Low-level inotify interface wrappers."; static void define_const(PyObject *dict, const char *name, uint32_t val) { PyObject *pyval = PyInt_FromLong(val); PyObject *pyname = PyString_FromString(name); if (!pyname || !pyval) goto bail; PyDict_SetItem(dict, pyname, pyval); bail: Py_XDECREF(pyname); Py_XDECREF(pyval); } static void define_consts(PyObject *dict) { define_const(dict, "IN_ACCESS", IN_ACCESS); define_const(dict, "IN_MODIFY", IN_MODIFY); define_const(dict, "IN_ATTRIB", IN_ATTRIB); define_const(dict, "IN_CLOSE_WRITE", IN_CLOSE_WRITE); define_const(dict, "IN_CLOSE_NOWRITE", IN_CLOSE_NOWRITE); define_const(dict, "IN_OPEN", IN_OPEN); define_const(dict, "IN_MOVED_FROM", IN_MOVED_FROM); define_const(dict, "IN_MOVED_TO", IN_MOVED_TO); define_const(dict, "IN_CLOSE", IN_CLOSE); define_const(dict, "IN_MOVE", IN_MOVE); define_const(dict, "IN_CREATE", IN_CREATE); define_const(dict, "IN_DELETE", IN_DELETE); define_const(dict, "IN_DELETE_SELF", IN_DELETE_SELF); define_const(dict, "IN_MOVE_SELF", IN_MOVE_SELF); define_const(dict, "IN_UNMOUNT", IN_UNMOUNT); define_const(dict, "IN_Q_OVERFLOW", IN_Q_OVERFLOW); define_const(dict, "IN_IGNORED", IN_IGNORED); define_const(dict, "IN_ONLYDIR", IN_ONLYDIR); define_const(dict, "IN_DONT_FOLLOW", IN_DONT_FOLLOW); define_const(dict, "IN_MASK_ADD", IN_MASK_ADD); define_const(dict, "IN_ISDIR", IN_ISDIR); define_const(dict, "IN_ONESHOT", IN_ONESHOT); define_const(dict, "IN_ALL_EVENTS", IN_ALL_EVENTS); } struct event { PyObject_HEAD PyObject *wd; PyObject *mask; PyObject *cookie; PyObject *name; }; static PyObject *event_wd(PyObject *self, void *x) { struct event *evt = (struct event *) self; Py_INCREF(evt->wd); return evt->wd; } static PyObject *event_mask(PyObject *self, void *x) { struct event *evt = (struct event *) self; Py_INCREF(evt->mask); return evt->mask; } static PyObject *event_cookie(PyObject *self, void *x) { struct event *evt = (struct event *) self; Py_INCREF(evt->cookie); return evt->cookie; } static PyObject *event_name(PyObject *self, void *x) { struct event *evt = (struct event *) self; Py_INCREF(evt->name); return evt->name; } static struct PyGetSetDef event_getsets[] = { {"wd", event_wd, NULL, "watch descriptor"}, {"mask", event_mask, NULL, "event mask"}, {"cookie", event_cookie, NULL, "rename cookie, if rename-related event"}, {"name", event_name, NULL, "file name"}, {NULL} }; PyDoc_STRVAR( event_doc, "event: Structure describing an inotify event."); static PyObject *event_new(PyTypeObject *t, PyObject *a, PyObject *k) { return (*t->tp_alloc)(t, 0); } static void event_dealloc(struct event *evt) { Py_XDECREF(evt->wd); Py_XDECREF(evt->mask); Py_XDECREF(evt->cookie); Py_XDECREF(evt->name); (*evt->ob_type->tp_free)(evt); } static PyObject *event_repr(struct event *evt) { int wd = PyInt_AsLong(evt->wd); int cookie = evt->cookie == Py_None ? -1 : PyInt_AsLong(evt->cookie); PyObject *ret = NULL, *pymasks = NULL, *pymask = NULL; PyObject *join = NULL; char *maskstr; join = PyString_FromString("|"); if (join == NULL) goto bail; pymasks = decode_mask(PyInt_AsLong(evt->mask)); if (pymasks == NULL) goto bail; pymask = _PyString_Join(join, pymasks); if (pymask == NULL) goto bail; maskstr = PyString_AsString(pymask); if (evt->name != Py_None) { PyObject *pyname = PyString_Repr(evt->name, 1); char *name = pyname ? PyString_AsString(pyname) : "???"; if (cookie == -1) ret = PyString_FromFormat("event(wd=%d, mask=%s, name=%s)", wd, maskstr, name); else ret = PyString_FromFormat("event(wd=%d, mask=%s, " "cookie=0x%x, name=%s)", wd, maskstr, cookie, name); Py_XDECREF(pyname); } else { if (cookie == -1) ret = PyString_FromFormat("event(wd=%d, mask=%s)", wd, maskstr); else { ret = PyString_FromFormat("event(wd=%d, mask=%s, cookie=0x%x)", wd, maskstr, cookie); } } goto done; bail: Py_CLEAR(ret); done: Py_XDECREF(pymask); Py_XDECREF(pymasks); Py_XDECREF(join); return ret; } static PyTypeObject event_type = { PyObject_HEAD_INIT(NULL) 0, /*ob_size*/ "_inotify.event", /*tp_name*/ sizeof(struct event), /*tp_basicsize*/ 0, /*tp_itemsize*/ (destructor)event_dealloc, /*tp_dealloc*/ 0, /*tp_print*/ 0, /*tp_getattr*/ 0, /*tp_setattr*/ 0, /*tp_compare*/ (reprfunc)event_repr, /*tp_repr*/ 0, /*tp_as_number*/ 0, /*tp_as_sequence*/ 0, /*tp_as_mapping*/ 0, /*tp_hash */ 0, /*tp_call*/ 0, /*tp_str*/ 0, /*tp_getattro*/ 0, /*tp_setattro*/ 0, /*tp_as_buffer*/ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ event_doc, /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ 0, /* tp_members */ event_getsets, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ 0, /* tp_init */ 0, /* tp_alloc */ event_new, /* tp_new */ }; PyObject *read_events(PyObject *self, PyObject *args) { PyObject *ctor_args = NULL; PyObject *pybufsize = NULL; PyObject *ret = NULL; int bufsize = 65536; char *buf = NULL; int nread, pos; int fd; if (!PyArg_ParseTuple(args, "i|O:read", &fd, &pybufsize)) goto bail; if (pybufsize && pybufsize != Py_None) bufsize = PyInt_AsLong(pybufsize); ret = PyList_New(0); if (ret == NULL) goto bail; if (bufsize <= 0) { int r; Py_BEGIN_ALLOW_THREADS r = ioctl(fd, FIONREAD, &bufsize); Py_END_ALLOW_THREADS if (r == -1) { PyErr_SetFromErrno(PyExc_OSError); goto bail; } if (bufsize == 0) goto done; } else { static long name_max; static long name_fd = -1; long min; if (name_fd != fd) { name_fd = fd; Py_BEGIN_ALLOW_THREADS name_max = fpathconf(fd, _PC_NAME_MAX); Py_END_ALLOW_THREADS } min = sizeof(struct inotify_event) + name_max + 1; if (bufsize < min) { PyErr_Format(PyExc_ValueError, "bufsize must be at least %d", (int) min); goto bail; } } buf = alloca(bufsize); Py_BEGIN_ALLOW_THREADS nread = read(fd, buf, bufsize); Py_END_ALLOW_THREADS if (nread == -1) { PyErr_SetFromErrno(PyExc_OSError); goto bail; } ctor_args = PyTuple_New(0); if (ctor_args == NULL) goto bail; pos = 0; while (pos < nread) { struct inotify_event *in = (struct inotify_event *) (buf + pos); struct event *evt; PyObject *obj; obj = PyObject_CallObject((PyObject *) &event_type, ctor_args); if (obj == NULL) goto bail; evt = (struct event *) obj; evt->wd = PyInt_FromLong(in->wd); evt->mask = PyInt_FromLong(in->mask); if (in->mask & IN_MOVE) evt->cookie = PyInt_FromLong(in->cookie); else { Py_INCREF(Py_None); evt->cookie = Py_None; } if (in->len) evt->name = PyString_FromString(in->name); else { Py_INCREF(Py_None); evt->name = Py_None; } if (!evt->wd || !evt->mask || !evt->cookie || !evt->name) goto mybail; if (PyList_Append(ret, obj) == -1) goto mybail; pos += sizeof(struct inotify_event) + in->len; continue; mybail: Py_CLEAR(evt->wd); Py_CLEAR(evt->mask); Py_CLEAR(evt->cookie); Py_CLEAR(evt->name); Py_DECREF(obj); goto bail; } goto done; bail: Py_CLEAR(ret); done: Py_XDECREF(ctor_args); return ret; } PyDoc_STRVAR( read_doc, "read(fd, bufsize[=65536]) -> list_of_events\n" "\n" "\nRead inotify events from a file descriptor.\n" "\n" " fd: file descriptor returned by init()\n" " bufsize: size of buffer to read into, in bytes\n" "\n" "Return a list of event objects.\n" "\n" "If bufsize is > 0, block until events are available to be read.\n" "Otherwise, immediately return all events that can be read without\n" "blocking."); static PyMethodDef methods[] = { {"init", init, METH_VARARGS, init_doc}, {"add_watch", add_watch, METH_VARARGS, add_watch_doc}, {"remove_watch", remove_watch, METH_VARARGS, remove_watch_doc}, {"read", read_events, METH_VARARGS, read_doc}, {"decode_mask", pydecode_mask, METH_VARARGS, decode_mask_doc}, {NULL}, }; void init_inotify(void) { PyObject *mod, *dict; if (PyType_Ready(&event_type) == -1) return; mod = Py_InitModule3("_inotify", methods, doc); dict = PyModule_GetDict(mod); if (dict) define_consts(dict); }