Merge pull request #2 from keszybz/master

Python 3 and UTF-8

Author: davidstrauss

.dir-locals.el

@@ -0,0 +1,7 @@
+; Sets emacs variables based on mode.
+; A list of (major-mode . ((var1 . value1) (var2 . value2)))
+; Mode can be nil, which gives default values.
+
+((nil . ((indent-tabs-mode . nil)
+         (c-basic-offset . 4)))
+)

.gitignore

@@ -1,4 +1,6 @@
+__pycache__/
 *.py[co]
+/journald/*.so
 
 # Packages
 *.egg

README.md

@@ -1,7 +1,9 @@
 journald-python
 ===============
 
-Python module for native access to the journald facilities in recent versions of systemd. In particular, this capability includes passing key/value pairs as fields that journald can use for filtering.
+Python module for native access to the journald facilities in recent
+versions of systemd. In particular, this capability includes passing
+key/value pairs as fields that journald can use for filtering.
 
 Installation
 ============
@@ -17,16 +19,35 @@ Usage
 Quick example:
 
     import journald
-    journald.send('MESSAGE=Hello world.')
-    journald.send('MESSAGE=Hello, again, world.', 'FIELD2=Greetings!', 'FIELD3=Guten tag.')
-    journald.send('ARBITRARY=anything', 'FIELD3=Greetings!')
+    journald.send('Hello world')
+    journald.send('Hello, again, world', FIELD2='Greetings!', FIELD3='Guten tag')
+    journald.send('Binary message', BINARY=b'\xde\xad\xbe\xef')
+
+There is one required argument -- the message, and additional fields
+can be specified as keyword arguments. Following the journald API, all
+names are uppercase.
+
+The journald sendv call can also be accessed directly:
+
+    import journald
+    journald.sendv('MESSAGE=Hello world')
+    journald.sendv('MESSAGE=Hello, again, world', 'FIELD2=Greetings!',
+                   'FIELD3=Guten tag')
+    journald.sendv('MESSAGE=Binary message', b'BINARY=\xde\xad\xbe\xef')
+
+The two examples should give the same results in the log.
 
 Notes:
 
- * Each argument must be in the form of a KEY=value pair, environmental variable style.
- * Unlike the native C version of journald's sd_journal_send(), printf-style substitution is not supported. Perform any substitution using Python's % operator or .format() capabilities first.
- * The base message is usually sent in the form MESSAGE=hello. The MESSAGE field is, however, not required.
- * Invalid or zero arguments results in nothing recorded in journald.
+ * Unlike the native C version of journald's sd_journal_send(),
+   printf-style substitution is not supported. Perform any
+   substitution using Python's % operator or .format() capabilities
+   first.
+ * The base message is usually sent in the form MESSAGE=hello. The
+   MESSAGE field is, however, not required.
+ * A ValueError is thrown is thrown if sd_journald_sendv() results in
+   an error. This might happen if there are no arguments or one of them
+   is invalid.
 
 Viewing Output
 ==============

journald.c

@@ -0,0 +1,54 @@
+from ._journald import sendv
+import traceback as _traceback
+
+def _make_line(field, value):
+    if isinstance(value, bytes):
+        return field.encode('utf-8') + b'=' + value
+    else:
+        return field + '=' + value
+
+def send(MESSAGE, MESSAGE_ID=None,
+         CODE_FILE=None, CODE_LINE=None, CODE_FUNC=None,
+         **kwargs):
+    r"""Send a message to journald.
+
+    >>> journald.send('Hello world')
+    >>> journald.send('Hello, again, world', FIELD2='Greetings!')
+    >>> journald.send('Binary message', BINARY=b'\xde\xad\xbe\xef')
+
+    Value of the MESSAGE argument will be used for the MESSAGE= field.
+
+    MESSAGE_ID can be given to uniquely identify the type of message.
+
+    Other parts of the message can be specified as keyword arguments.
+
+    Both MESSAGE and MESSAGE_ID, if present, must be strings, and will
+    be sent as UTF-8 to journald. Other arguments can be bytes, in
+    which case they will be sent as-is to journald.
+
+    CODE_LINE, CODE_FILE, and CODE_FUNC can be specified to identify
+    the caller. Unless at least on of the three is given, values are
+    extracted from the stack frame of the caller of send(). CODE_FILE
+    and CODE_FUNC must be strings, CODE_LINE must be an integer.
+
+    Other useful fields include PRIORITY, SYSLOG_FACILITY,
+    SYSLOG_IDENTIFIER, SYSLOG_PID.
+    """
+
+    args = ['MESSAGE=' + MESSAGE]
+
+    if MESSAGE_ID is not None:
+        args.append('MESSAGE_ID=' + MESSAGE_ID)
+
+    if CODE_LINE == CODE_FILE == CODE_FUNC == None:
+        CODE_FILE, CODE_LINE, CODE_FUNC = \
+            _traceback.extract_stack(limit=2)[0][:3]
+    if CODE_FILE is not None:
+        args.append('CODE_FILE=' + CODE_FILE)
+    if CODE_LINE is not None:
+        args.append('CODE_LINE={:d}'.format(CODE_LINE))
+    if CODE_FUNC is not None:
+        args.append('CODE_FUNC=' + CODE_FUNC)
+
+    args.extend(_make_line(key, val) for key, val in kwargs.items())
+    return sendv(*args)

journald/__init__.py

@@ -0,0 +1,111 @@
+#include <Python.h>
+#define SD_JOURNAL_SUPPRESS_LOCATION
+#include <systemd/sd-journal.h>
+
+PyDoc_STRVAR(journald_sendv__doc__,
+             "sendv('FIELD=value', 'FIELD=value', ...) -> None\n\n"
+             "Send an entry to journald."
+             );
+
+static PyObject *
+journald_sendv(PyObject *self, PyObject *args) {
+    struct iovec *iov = NULL;
+    int argc = PyTuple_Size(args);
+    int i, r;
+    PyObject *ret = NULL;
+
+    PyObject **encoded = calloc(argc, sizeof(PyObject*));
+    if (!encoded) {
+        ret = PyErr_NoMemory();
+        goto out1;
+    }
+
+    // Allocate sufficient iovector space for the arguments.
+    iov = malloc(argc * sizeof(struct iovec));
+    if (!iov) {
+        ret = PyErr_NoMemory();
+        goto out;
+    }
+
+    // Iterate through the Python arguments and fill the iovector.
+    for (i = 0; i < argc; ++i) {
+        PyObject *item = PyTuple_GetItem(args, i);
+        char *stritem;
+        Py_ssize_t length;
+
+        if (PyUnicode_Check(item)) {
+            encoded[i] = PyUnicode_AsEncodedString(item, "utf-8", "strict");
+            if (encoded[i] == NULL)
+                goto out;
+            item = encoded[i];
+        }
+        if (PyBytes_AsStringAndSize(item, &stritem, &length))
+            goto out;
+
+        iov[i].iov_base = stritem;
+        iov[i].iov_len = length;
+    }
+
+    // Clear errno, because sd_journal_sendv will not set it by
+    // itself, unless an error occurs in one of the system calls.
+    errno = 0;
+
+    // Send the iovector to journald.
+    r = sd_journal_sendv(iov, argc);
+
+    if (r) {
+        if (errno)
+            PyErr_SetFromErrno(PyExc_IOError);
+        else
+            PyErr_SetString(PyExc_ValueError, "invalid message format");
+        goto out;
+    }
+
+    // End with success.
+    Py_INCREF(Py_None);
+    ret = Py_None;
+
+out:
+    for (i = 0; i < argc; ++i)
+        Py_XDECREF(encoded[i]);
+
+    free(encoded);
+
+out1:
+    // Free the iovector. The actual strings
+    // are already managed by Python.
+    free(iov);
+
+    return ret;
+}
+
+static PyMethodDef methods[] = {
+    {"sendv",  journald_sendv, METH_VARARGS, journald_sendv__doc__},
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+#if PY_MAJOR_VERSION < 3
+
+PyMODINIT_FUNC
+init_journald(void)
+{
+    (void) Py_InitModule("_journald", methods);
+}
+
+#else
+
+static struct PyModuleDef module = {
+    PyModuleDef_HEAD_INIT,
+    "_journald", /* name of module */
+    NULL, /* module documentation, may be NULL */
+    0, /* size of per-interpreter state of the module */
+    methods
+};
+
+PyMODINIT_FUNC
+PyInit__journald(void)
+{
+    return PyModule_Create(&module);
+}
+
+#endif

journald/_journald.c

@@ -1,12 +1,13 @@
 from distutils.core import setup, Extension
 
-journald = Extension('journald',
-                     libraries = ['systemd-journal'],
-                     sources = ['journald.c'])
+cjournald = Extension('journald/_journald',
+                      libraries = ['systemd-journal'],
+                      sources = ['journald/_journald.c'])
 
 setup (name = 'journald',
        version = '0.1',
        description = 'Native interface to the journald facilities of systemd',
        author_email = 'david@davidstrauss.net',
        url = 'https://github.com/davidstrauss/journald-python',
-       ext_modules = [journald])
+       py_modules = ['journald'],
+       ext_modules = [cjournald])