chiark / gitweb /
systemd-python: fix gcc warning
[elogind.git] / src / python-systemd / _reader.c
index c16cbdcd763b46f1bb3cadf8b665ed76c6a8a406..a678f69318055c94b14179aa3f13a7771d5b1a21 100644 (file)
@@ -1,4 +1,4 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+/*-*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*-*/
 
 /***
   This file is part of systemd.
   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
-#include <systemd/sd-journal.h>
 
 #include <Python.h>
 #include <structmember.h>
 #include <datetime.h>
+#include <time.h>
+#include <stdio.h>
+
+#include <systemd/sd-journal.h>
+
+#include "pyutil.h"
+#include "macro.h"
+#include "util.h"
+#include "strv.h"
+#include "build.h"
 
 typedef struct {
     PyObject_HEAD
     sd_journal *j;
-} Journal;
-static PyTypeObject JournalType;
+} Reader;
+static PyTypeObject ReaderType;
+
+
+PyDoc_STRVAR(module__doc__,
+             "Class to reads the systemd journal similar to journalctl.");
+
+
+#if PY_MAJOR_VERSION >= 3
+static PyTypeObject MonotonicType;
+
+PyDoc_STRVAR(MonotonicType__doc__,
+             "A tuple of (timestamp, bootid) for holding monotonic timestamps");
+
+static PyStructSequence_Field MonotonicType_fields[] = {
+    {(char*) "timestamp", (char*) "Time"},
+    {(char*) "bootid", (char*) "Unique identifier of the boot"},
+    {} /* Sentinel */
+};
 
-static void
-Journal_dealloc(Journal* self)
+static PyStructSequence_Desc Monotonic_desc = {
+    (char*) "journal.Monotonic",
+    MonotonicType__doc__,
+    MonotonicType_fields,
+    2,
+};
+#endif
+
+static int strv_converter(PyObject* obj, void *_result) {
+        char ***result = _result;
+        Py_ssize_t i, len;
+
+        assert(result);
+
+        if (!obj)
+            goto cleanup;
+
+        if (!PySequence_Check(obj))
+            return 0;
+
+        len = PySequence_Length(obj);
+        *result = new0(char*, len + 1);
+
+        for (i = 0; i < len; i++) {
+            PyObject *item;
+#if PY_MAJOR_VERSION >=3 && PY_MINOR_VERSION >= 1
+            int r;
+            PyObject *bytes;
+#endif
+            char *s, *s2;
+
+            item = PySequence_ITEM(obj, i);
+#if PY_MAJOR_VERSION >=3 && PY_MINOR_VERSION >= 1
+            r = PyUnicode_FSConverter(item, &bytes);
+            if (r == 0)
+                goto cleanup;
+
+            s = PyBytes_AsString(bytes);
+#else
+            s = PyString_AsString(item);
+#endif
+            if (!s)
+                goto cleanup;
+
+            s2 = strdup(s);
+            if (!s2)
+                log_oom();
+
+            (*result)[i] = s2;
+        }
+
+        return 1;
+
+cleanup:
+        strv_free(*result);
+        *result = NULL;
+
+        return 0;
+}
+
+static void Reader_dealloc(Reader* self)
 {
     sd_journal_close(self->j);
     Py_TYPE(self)->tp_free((PyObject*)self);
 }
 
-PyDoc_STRVAR(Journal__doc__,
-"Journal([flags][,path]) -> ...\n"
-"Journal instance\n\n"
-"Returns instance of Journal, which allows filtering and return\n"
-"of journal entries.\n"
-"Argument `flags` sets open flags of the journal, which can be one\n"
-"of, or ORed combination of constants: LOCAL_ONLY (default) opens\n"
-"journal on local machine only; RUNTIME_ONLY opens only\n"
-"volatile journal files; and SYSTEM_ONLY opens only\n"
-"journal files of system services and the kernel.\n"
-"Argument `path` is the directory of journal files. Note that\n"
-"currently flags are ignored when `path` is present as they are\n"
-" not relevant.");
-static int
-Journal_init(Journal *self, PyObject *args, PyObject *keywds)
-{
-    int flags=SD_JOURNAL_LOCAL_ONLY;
-    char *path=NULL;
-
-    static char *kwlist[] = {"flags", "path", NULL};
-    if (! PyArg_ParseTupleAndKeywords(args, keywds, "|is", kwlist,
-                                      &flags, &path))
-        return 1;
+PyDoc_STRVAR(Reader__doc__,
+             "_Reader([flags | path | files]) -> ...\n\n"
+             "_Reader allows filtering and retrieval of Journal entries.\n"
+             "Note: this is a low-level interface, and probably not what you\n"
+             "want, use systemd.journal.Reader instead.\n\n"
+             "Argument `flags` sets open flags of the journal, which can be one\n"
+             "of, or ORed combination of constants: LOCAL_ONLY (default) opens\n"
+             "journal on local machine only; RUNTIME_ONLY opens only\n"
+             "volatile journal files; and SYSTEM opens journal files of\n"
+             "system services and the kernel, and CURRENT_USER opens files\n"
+             "of the current user.\n\n"
+             "Argument `path` is the directory of journal files.\n"
+             "Argument `files` is a list of files. Note that\n"
+             "`flags`, `path`, and `files` are exclusive.\n\n"
+             "_Reader implements the context manager protocol: the journal\n"
+             "will be closed when exiting the block.");
+static int Reader_init(Reader *self, PyObject *args, PyObject *keywds)
+{
+    int flags = 0, r;
+    char *path = NULL;
+    char **files = NULL;
+
+    static const char* const kwlist[] = {"flags", "path", "files", NULL};
+    if (!PyArg_ParseTupleAndKeywords(args, keywds, "|izO&", (char**) kwlist,
+                                     &flags, &path, strv_converter, &files))
+        return -1;
+
+    if (!!flags + !!path + !!files > 1) {
+        PyErr_SetString(PyExc_ValueError, "cannot use more than one of flags, path, and files");
+        return -1;
+    }
+
+    if (!flags)
+        flags = SD_JOURNAL_LOCAL_ONLY;
 
-    int r;
     Py_BEGIN_ALLOW_THREADS
-    if (path) {
+    if (path)
         r = sd_journal_open_directory(&self->j, path, 0);
-    }else{
+    else if (files)
+        r = sd_journal_open_files(&self->j, (const char**) files, 0);
+    else
         r = sd_journal_open(&self->j, flags);
-    }
     Py_END_ALLOW_THREADS
-    if (r < 0) {
-        errno = -r;
-        PyObject *errtype = r == -EINVAL ? PyExc_ValueError :
-                            r == -ENOMEM ? PyExc_MemoryError :
-                            PyExc_OSError;
-        PyErr_SetFromErrnoWithFilename(errtype, path);
-        return -1;
-    }
 
-    return 0;
+    return set_error(r, path, "Invalid flags or path");
+}
+
+
+PyDoc_STRVAR(Reader_fileno__doc__,
+             "fileno() -> int\n\n"
+             "Get a file descriptor to poll for changes in the journal.\n"
+             "This method invokes sd_journal_get_fd().\n"
+             "See man:sd_journal_get_fd(3).");
+static PyObject* Reader_fileno(Reader *self, PyObject *args)
+{
+    int fd = sd_journal_get_fd(self->j);
+    set_error(fd, NULL, NULL);
+    if (fd < 0)
+        return NULL;
+    return long_FromLong(fd);
+}
+
+
+PyDoc_STRVAR(Reader_reliable_fd__doc__,
+             "reliable_fd() -> bool\n\n"
+             "Returns True iff the journal can be polled reliably.\n"
+             "This method invokes sd_journal_reliable_fd().\n"
+             "See man:sd_journal_reliable_fd(3).");
+static PyObject* Reader_reliable_fd(Reader *self, PyObject *args)
+{
+    int r = sd_journal_reliable_fd(self->j);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
+    return PyBool_FromLong(r);
+}
+
+
+PyDoc_STRVAR(Reader_get_events__doc__,
+             "get_events() -> int\n\n"
+             "Returns a mask of poll() events to wait for on the file\n"
+             "descriptor returned by .fileno().\n\n"
+             "See man:sd_journal_get_events(3) for further discussion.");
+static PyObject* Reader_get_events(Reader *self, PyObject *args)
+{
+    int r = sd_journal_get_events(self->j);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
+    return long_FromLong(r);
+}
+
+
+PyDoc_STRVAR(Reader_get_timeout__doc__,
+             "get_timeout() -> int or None\n\n"
+             "Returns a timeout value for usage in poll(), the time since the\n"
+             "epoch of clock_gettime(2) in microseconds, or None if no timeout\n"
+             "is necessary.\n\n"
+             "The return value must be converted to a relative timeout in\n"
+             "milliseconds if it is to be used as an argument for poll().\n"
+             "See man:sd_journal_get_timeout(3) for further discussion.");
+static PyObject* Reader_get_timeout(Reader *self, PyObject *args)
+{
+    int r;
+    uint64_t t;
+
+    r = sd_journal_get_timeout(self->j, &t);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
+
+    if (t == (uint64_t) -1)
+        Py_RETURN_NONE;
+
+    assert_cc(sizeof(unsigned long long) == sizeof(t));
+    return PyLong_FromUnsignedLongLong(t);
+}
+
+
+PyDoc_STRVAR(Reader_get_timeout_ms__doc__,
+             "get_timeout_ms() -> int\n\n"
+             "Returns a timeout value suitable for usage in poll(), the value\n"
+             "returned by .get_timeout() converted to relative ms, or -1 if\n"
+             "no timeout is necessary.");
+static PyObject* Reader_get_timeout_ms(Reader *self, PyObject *args)
+{
+    int r;
+    uint64_t t;
+
+    r = sd_journal_get_timeout(self->j, &t);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
+
+    return absolute_timeout(t);
+}
+
+
+PyDoc_STRVAR(Reader_close__doc__,
+             "close() -> None\n\n"
+             "Free resources allocated by this Reader object.\n"
+             "This method invokes sd_journal_close().\n"
+             "See man:sd_journal_close(3).");
+static PyObject* Reader_close(Reader *self, PyObject *args)
+{
+    assert(self);
+    assert(!args);
+
+    sd_journal_close(self->j);
+    self->j = NULL;
+    Py_RETURN_NONE;
+}
+
+
+PyDoc_STRVAR(Reader_get_usage__doc__,
+             "get_usage() -> int\n\n"
+             "Returns the total disk space currently used by journal\n"
+             "files (in bytes). If `SD_JOURNAL_LOCAL_ONLY` was\n"
+             "passed when opening the journal this value will only reflect\n"
+             "the size of journal files of the local host, otherwise\n"
+             "of all hosts.\n\n"
+             "This method invokes sd_journal_get_usage().\n"
+             "See man:sd_journal_get_usage(3).");
+static PyObject* Reader_get_usage(Reader *self, PyObject *args)
+{
+    int r;
+    uint64_t bytes;
+
+    r = sd_journal_get_usage(self->j, &bytes);
+    if (set_error(r, NULL, NULL))
+        return NULL;
+
+    assert_cc(sizeof(unsigned long long) == sizeof(bytes));
+    return PyLong_FromUnsignedLongLong(bytes);
+}
+
+
+PyDoc_STRVAR(Reader___enter____doc__,
+             "__enter__() -> self\n\n"
+             "Part of the context manager protocol.\n"
+             "Returns self.\n");
+static PyObject* Reader___enter__(PyObject *self, PyObject *args)
+{
+    assert(self);
+    assert(!args);
+
+    Py_INCREF(self);
+    return self;
+}
+
+PyDoc_STRVAR(Reader___exit____doc__,
+             "__exit__(type, value, traceback) -> None\n\n"
+             "Part of the context manager protocol.\n"
+             "Closes the journal.\n");
+static PyObject* Reader___exit__(Reader *self, PyObject *args)
+{
+    return Reader_close(self, args);
 }
 
-PyDoc_STRVAR(Journal_get_next__doc__,
-"get_next([skip]) -> dict\n\n"
-"Return dictionary of the next log entry. Optional skip value will\n"
-"return the `skip`th log entry.");
-static PyObject *
-Journal_get_next(Journal *self, PyObject *args)
+
+PyDoc_STRVAR(Reader_next__doc__,
+             "next([skip]) -> bool\n\n"
+             "Go to the next log entry. Optional skip value means to go to\n"
+             "the `skip`\\-th log entry.\n"
+             "Returns False if at end of file, True otherwise.");
+static PyObject* Reader_next(Reader *self, PyObject *args)
 {
-    int64_t skip=1LL;
-    if (! PyArg_ParseTuple(args, "|L", &skip))
+    int64_t skip = 1LL;
+    int r;
+
+    if (!PyArg_ParseTuple(args, "|L:next", &skip))
         return NULL;
 
     if (skip == 0LL) {
-        PyErr_SetString(PyExc_ValueError, "Skip number must positive/negative integer");
+        PyErr_SetString(PyExc_ValueError, "skip must be nonzero");
         return NULL;
     }
 
-    int r = -EINVAL;
     Py_BEGIN_ALLOW_THREADS
-    if (skip == 1LL) {
+    if (skip == 1LL)
         r = sd_journal_next(self->j);
-    }else if (skip == -1LL) {
+    else if (skip == -1LL)
         r = sd_journal_previous(self->j);
-    }else if (skip > 1LL) {
+    else if (skip > 1LL)
         r = sd_journal_next_skip(self->j, skip);
-    }else if (skip < -1LL) {
+    else if (skip < -1LL)
         r = sd_journal_previous_skip(self->j, -skip);
-    }
+    else
+        assert_not_reached("should not be here");
     Py_END_ALLOW_THREADS
 
-    if (r < 0) {
-        errno = -r;
-        PyErr_SetFromErrno(PyExc_OSError);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
+    return PyBool_FromLong(r);
+}
+
+PyDoc_STRVAR(Reader_previous__doc__,
+             "previous([skip]) -> bool\n\n"
+             "Go to the previous log entry. Optional skip value means to \n"
+             "go to the `skip`\\-th previous log entry.\n"
+             "Returns False if at start of file, True otherwise.");
+static PyObject* Reader_previous(Reader *self, PyObject *args)
+{
+    int64_t skip = 1LL;
+    if (!PyArg_ParseTuple(args, "|L:previous", &skip))
         return NULL;
-    }else if ( r == 0) { //EOF
-        return PyDict_New();
+
+    return PyObject_CallMethod((PyObject *)self, (char*) "_next",
+                               (char*) "L", -skip);
+}
+
+
+static int extract(const char* msg, size_t msg_len,
+                   PyObject **key, PyObject **value) {
+    PyObject *k = NULL, *v;
+    const char *delim_ptr;
+
+    delim_ptr = memchr(msg, '=', msg_len);
+    if (!delim_ptr) {
+        PyErr_SetString(PyExc_OSError,
+                        "journal gave us a field without '='");
+        return -1;
     }
 
-    PyObject *dict;
-    dict = PyDict_New();
+    if (key) {
+        k = unicode_FromStringAndSize(msg, delim_ptr - (const char*) msg);
+        if (!k)
+            return -1;
+    }
+
+    if (value) {
+        v = PyBytes_FromStringAndSize(delim_ptr + 1,
+                             (const char*) msg + msg_len - (delim_ptr + 1));
+        if (!v) {
+            Py_XDECREF(k);
+            return -1;
+        }
+
+        *value = v;
+    }
 
+    if (key)
+        *key = k;
+
+    return 0;
+}
+
+PyDoc_STRVAR(Reader_get__doc__,
+             "get(str) -> str\n\n"
+             "Return data associated with this key in current log entry.\n"
+             "Throws KeyError is the data is not available.");
+static PyObject* Reader_get(Reader *self, PyObject *args)
+{
+    const char* field;
+    const void* msg;
+    size_t msg_len;
+    PyObject *value;
+    int r;
+
+    assert(self);
+    assert(args);
+
+    if (!PyArg_ParseTuple(args, "s:get", &field))
+        return NULL;
+
+    r = sd_journal_get_data(self->j, field, &msg, &msg_len);
+    if (r == -ENOENT) {
+        PyErr_SetString(PyExc_KeyError, field);
+        return NULL;
+    } else if (set_error(r, NULL, "field name is not valid"))
+        return NULL;
+
+    r = extract(msg, msg_len, NULL, &value);
+    if (r < 0)
+        return NULL;
+    return value;
+}
+
+
+PyDoc_STRVAR(Reader_get_all__doc__,
+             "_get_all() -> dict\n\n"
+             "Return dictionary of the current log entry.");
+static PyObject* Reader_get_all(Reader *self, PyObject *args)
+{
+    PyObject *dict;
     const void *msg;
     size_t msg_len;
-    const char *delim_ptr;
-    PyObject *key, *value, *cur_value, *tmp_list;
+    int r;
+
+    dict = PyDict_New();
+    if (!dict)
+            return NULL;
 
     SD_JOURNAL_FOREACH_DATA(self->j, msg, msg_len) {
-        delim_ptr = memchr(msg, '=', msg_len);
-#if PY_MAJOR_VERSION >=3
-        key = PyUnicode_FromStringAndSize(msg, delim_ptr - (const char*) msg);
-#else
-        key = PyString_FromStringAndSize(msg, delim_ptr - (const char*) msg);
-#endif
-        value = PyBytes_FromStringAndSize(delim_ptr + 1, (const char*) msg + msg_len - (delim_ptr + 1) );
+        _cleanup_Py_DECREF_ PyObject *key = NULL, *value = NULL;
+
+        r = extract(msg, msg_len, &key, &value);
+        if (r < 0)
+            goto error;
+
         if (PyDict_Contains(dict, key)) {
-            cur_value = PyDict_GetItem(dict, key);
+            PyObject *cur_value = PyDict_GetItem(dict, key);
+
             if (PyList_CheckExact(cur_value)) {
-                PyList_Append(cur_value, value);
-            }else{
-                tmp_list = PyList_New(0);
-                PyList_Append(tmp_list, cur_value);
-                PyList_Append(tmp_list, value);
-                PyDict_SetItem(dict, key, tmp_list);
-                Py_DECREF(tmp_list);
+                r = PyList_Append(cur_value, value);
+                if (r < 0)
+                    goto error;
+            } else {
+                _cleanup_Py_DECREF_ PyObject *tmp_list = PyList_New(0);
+                if (!tmp_list)
+                    goto error;
+
+                r = PyList_Append(tmp_list, cur_value);
+                if (r < 0)
+                    goto error;
+
+                r = PyList_Append(tmp_list, value);
+                if (r < 0)
+                    goto error;
+
+                r = PyDict_SetItem(dict, key, tmp_list);
+                if (r < 0)
+                    goto error;
             }
-        }else{
-            PyDict_SetItem(dict, key, value);
+        } else {
+            r = PyDict_SetItem(dict, key, value);
+            if (r < 0)
+                goto error;
         }
-        Py_DECREF(key);
-        Py_DECREF(value);
     }
 
-    uint64_t realtime;
-    if (sd_journal_get_realtime_usec(self->j, &realtime) == 0) {
-        char realtime_str[20];
-        sprintf(realtime_str, "%llu", (long long unsigned) realtime);
+    return dict;
 
-#if PY_MAJOR_VERSION >=3
-        key = PyUnicode_FromString("__REALTIME_TIMESTAMP");
-#else
-        key = PyString_FromString("__REALTIME_TIMESTAMP");
-#endif
-        value = PyBytes_FromString(realtime_str);
-        PyDict_SetItem(dict, key, value);
-        Py_DECREF(key);
-        Py_DECREF(value);
-    }
+error:
+    Py_DECREF(dict);
+    return NULL;
+}
 
-    sd_id128_t sd_id;
-    uint64_t monotonic;
-    if (sd_journal_get_monotonic_usec(self->j, &monotonic, &sd_id) == 0) {
-        char monotonic_str[20];
-        sprintf(monotonic_str, "%llu", (long long unsigned) monotonic);
-#if PY_MAJOR_VERSION >=3
-        key = PyUnicode_FromString("__MONOTONIC_TIMESTAMP");
-#else
-        key = PyString_FromString("__MONOTONIC_TIMESTAMP");
-#endif
-        value = PyBytes_FromString(monotonic_str);
 
-        PyDict_SetItem(dict, key, value);
-        Py_DECREF(key);
-        Py_DECREF(value);
-    }
+PyDoc_STRVAR(Reader_get_realtime__doc__,
+             "get_realtime() -> int\n\n"
+             "Return the realtime timestamp for the current journal entry\n"
+             "in microseconds.\n\n"
+             "Wraps sd_journal_get_realtime_usec().\n"
+             "See man:sd_journal_get_realtime_usec(3).");
+static PyObject* Reader_get_realtime(Reader *self, PyObject *args)
+{
+    uint64_t timestamp;
+    int r;
 
-    char *cursor;
-    if (sd_journal_get_cursor(self->j, &cursor) > 0) { //Should return 0...
-#if PY_MAJOR_VERSION >=3
-        key = PyUnicode_FromString("__CURSOR");
-#else
-        key = PyString_FromString("__CURSOR");
-#endif
-        value = PyBytes_FromString(cursor);
-        PyDict_SetItem(dict, key, value);
-        free(cursor);
-        Py_DECREF(key);
-        Py_DECREF(value);
-    }
+    assert(self);
+    assert(!args);
 
-    return dict;
+    r = sd_journal_get_realtime_usec(self->j, &timestamp);
+    if (set_error(r, NULL, NULL))
+        return NULL;
+
+    assert_cc(sizeof(unsigned long long) == sizeof(timestamp));
+    return PyLong_FromUnsignedLongLong(timestamp);
 }
 
-PyDoc_STRVAR(Journal_get_previous__doc__,
-"get_previous([skip]) -> dict\n\n"
-"Return dictionary of the previous log entry. Optional skip value\n"
-"will return the -`skip`th log entry. Equivalent to get_next(-skip).");
-static PyObject *
-Journal_get_previous(Journal *self, PyObject *args)
+
+PyDoc_STRVAR(Reader_get_monotonic__doc__,
+             "get_monotonic() -> (timestamp, bootid)\n\n"
+             "Return the monotonic timestamp for the current journal entry\n"
+             "as a tuple of time in microseconds and bootid.\n\n"
+             "Wraps sd_journal_get_monotonic_usec().\n"
+             "See man:sd_journal_get_monotonic_usec(3).");
+static PyObject* Reader_get_monotonic(Reader *self, PyObject *args)
 {
-    int64_t skip=1LL;
-    if (! PyArg_ParseTuple(args, "|L", &skip))
+    uint64_t timestamp;
+    sd_id128_t id;
+    PyObject *monotonic, *bootid, *tuple;
+    int r;
+
+    assert(self);
+    assert(!args);
+
+    r = sd_journal_get_monotonic_usec(self->j, &timestamp, &id);
+    if (set_error(r, NULL, NULL))
+        return NULL;
+
+    assert_cc(sizeof(unsigned long long) == sizeof(timestamp));
+    monotonic = PyLong_FromUnsignedLongLong(timestamp);
+    bootid = PyBytes_FromStringAndSize((const char*) &id.bytes, sizeof(id.bytes));
+#if PY_MAJOR_VERSION >= 3
+    tuple = PyStructSequence_New(&MonotonicType);
+#else
+    tuple = PyTuple_New(2);
+#endif
+    if (!monotonic || !bootid || !tuple) {
+        Py_XDECREF(monotonic);
+        Py_XDECREF(bootid);
+        Py_XDECREF(tuple);
         return NULL;
+    }
+
+#if PY_MAJOR_VERSION >= 3
+    PyStructSequence_SET_ITEM(tuple, 0, monotonic);
+    PyStructSequence_SET_ITEM(tuple, 1, bootid);
+#else
+    PyTuple_SET_ITEM(tuple, 0, monotonic);
+    PyTuple_SET_ITEM(tuple, 1, bootid);
+#endif
 
-    return PyObject_CallMethod((PyObject *)self, "get_next", "L", -skip);
+    return tuple;
 }
 
-PyDoc_STRVAR(Journal_add_match__doc__,
-"add_match(match) -> None\n\n"
-"Add a match to filter journal log entries. All matches of different\n"
-"fields are combined in logical AND, and matches of the same field\n"
-"are automatically combined in logical OR.\n"
-"Match is string of form \"field=value\".");
-static PyObject *
-Journal_add_match(Journal *self, PyObject *args, PyObject *keywds)
+PyDoc_STRVAR(Reader_add_match__doc__,
+             "add_match(match) -> None\n\n"
+             "Add a match to filter journal log entries. All matches of different\n"
+             "fields are combined with logical AND, and matches of the same field\n"
+             "are automatically combined with logical OR.\n"
+             "Match is a string of the form \"FIELD=value\".");
+static PyObject* Reader_add_match(Reader *self, PyObject *args, PyObject *keywds)
 {
     char *match;
-    int match_len;
-    if (! PyArg_ParseTuple(args, "s#", &match, &match_len))
+    int match_len, r;
+    if (!PyArg_ParseTuple(args, "s#:add_match", &match, &match_len))
         return NULL;
 
-    int r;
     r = sd_journal_add_match(self->j, match, match_len);
-    if (r < 0) {
-        errno = -r;
-        PyObject *errtype = r == -EINVAL ? PyExc_ValueError :
-                            r == -ENOMEM ? PyExc_MemoryError :
-                            PyExc_OSError;
-        PyErr_SetFromErrno(errtype);
-        return NULL;
-    }
+    set_error(r, NULL, "Invalid match");
+    if (r < 0)
+            return NULL;
 
     Py_RETURN_NONE;
 }
 
-PyDoc_STRVAR(Journal_add_disjunction__doc__,
-"add_disjunction() -> None\n\n"
-"Once called, all matches before and after are combined in logical\n"
-"OR.");
-static PyObject *
-Journal_add_disjunction(Journal *self, PyObject *args)
+
+PyDoc_STRVAR(Reader_add_disjunction__doc__,
+             "add_disjunction() -> None\n\n"
+             "Inserts a logical OR between matches added since previous\n"
+             "add_disjunction() or add_conjunction() and the next\n"
+             "add_disjunction() or add_conjunction().\n\n"
+             "See man:sd_journal_add_disjunction(3) for explanation.");
+static PyObject* Reader_add_disjunction(Reader *self, PyObject *args)
 {
     int r;
     r = sd_journal_add_disjunction(self->j);
-    if (r < 0) {
-        errno = -r;
-        PyObject *errtype = r == -ENOMEM ? PyExc_MemoryError :
-                            PyExc_OSError;
-        PyErr_SetFromErrno(errtype);
+    set_error(r, NULL, NULL);
+    if (r < 0)
         return NULL;
-    }
     Py_RETURN_NONE;
 }
 
-PyDoc_STRVAR(Journal_flush_matches__doc__,
-"flush_matches() -> None\n\n"
-"Clears all current match filters.");
-static PyObject *
-Journal_flush_matches(Journal *self, PyObject *args)
+
+PyDoc_STRVAR(Reader_add_conjunction__doc__,
+             "add_conjunction() -> None\n\n"
+             "Inserts a logical AND between matches added since previous\n"
+             "add_disjunction() or add_conjunction() and the next\n"
+             "add_disjunction() or add_conjunction().\n\n"
+             "See man:sd_journal_add_disjunction(3) for explanation.");
+static PyObject* Reader_add_conjunction(Reader *self, PyObject *args)
 {
-    sd_journal_flush_matches(self->j);
+    int r;
+    r = sd_journal_add_conjunction(self->j);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
     Py_RETURN_NONE;
 }
 
-PyDoc_STRVAR(Journal_seek__doc__,
-"seek(offset[, whence]) -> None\n\n"
-"Seek through journal by `offset` number of entries. Argument\n"
-"`whence` defines what the offset is relative to:\n"
-"os.SEEK_SET (default) from first match in journal;\n"
-"os.SEEK_CUR from current position in journal;\n"
-"and os.SEEK_END is from last match in journal.");
-static PyObject *
-Journal_seek(Journal *self, PyObject *args, PyObject *keywds)
+
+PyDoc_STRVAR(Reader_flush_matches__doc__,
+             "flush_matches() -> None\n\n"
+             "Clear all current match filters.");
+static PyObject* Reader_flush_matches(Reader *self, PyObject *args)
 {
-    int64_t offset;
-    int whence=SEEK_SET;
-    static char *kwlist[] = {"offset", "whence", NULL};
+    sd_journal_flush_matches(self->j);
+    Py_RETURN_NONE;
+}
 
-    if (! PyArg_ParseTupleAndKeywords(args, keywds, "L|i", kwlist,
-                                      &offset, &whence))
-        return NULL;
 
-    PyObject *result=NULL;
-    if (whence == SEEK_SET){
-        int r;
-        Py_BEGIN_ALLOW_THREADS
-        r = sd_journal_seek_head(self->j);
-        Py_END_ALLOW_THREADS
-        if (r < 0) {
-            errno = -r;
-            PyErr_SetFromErrno(PyExc_OSError);
-            return NULL;
-        }
-        if (offset > 0LL) {
-            result = PyObject_CallMethod((PyObject *)self, "get_next", "L", offset);
-        }
-    }else if (whence == SEEK_CUR){
-        result = PyObject_CallMethod((PyObject *)self, "get_next", "L", offset);
-    }else if (whence == SEEK_END){
-        int r;
-        Py_BEGIN_ALLOW_THREADS
-        r = sd_journal_seek_tail(self->j);
-        Py_END_ALLOW_THREADS
-        if (r < 0) {
-            errno = -r;
-            PyErr_SetFromErrno(PyExc_OSError);
-            return NULL;
-        }
-        if (offset < 0LL) {
-            result = PyObject_CallMethod((PyObject *)self, "get_next", "L", offset);
-        }else{
-            result = PyObject_CallMethod((PyObject *)self, "get_next", "L", -1LL);
-        }
-    }else{
-        PyErr_SetString(PyExc_ValueError, "Invalid value for whence");
-    }
-
-    if (result)
-        Py_DECREF(result);
-    if (PyErr_Occurred())
+PyDoc_STRVAR(Reader_seek_head__doc__,
+             "seek_head() -> None\n\n"
+             "Jump to the beginning of the journal.\n"
+             "This method invokes sd_journal_seek_head().\n"
+             "See man:sd_journal_seek_head(3).");
+static PyObject* Reader_seek_head(Reader *self, PyObject *args)
+{
+    int r;
+    Py_BEGIN_ALLOW_THREADS
+    r = sd_journal_seek_head(self->j);
+    Py_END_ALLOW_THREADS
+    if (set_error(r, NULL, NULL))
         return NULL;
     Py_RETURN_NONE;
 }
 
-PyDoc_STRVAR(Journal_seek_realtime__doc__,
-"seek_realtime(realtime) -> None\n\n"
-"Seek to nearest matching journal entry to `realtime`. Argument\n"
-"`realtime` can must be an integer unix timestamp.");
-static PyObject *
-Journal_seek_realtime(Journal *self, PyObject *args)
+
+PyDoc_STRVAR(Reader_seek_tail__doc__,
+             "seek_tail() -> None\n\n"
+             "Jump to the end of the journal.\n"
+             "This method invokes sd_journal_seek_tail().\n"
+             "See man:sd_journal_seek_tail(3).");
+static PyObject* Reader_seek_tail(Reader *self, PyObject *args)
 {
-    double timedouble;
-    if (! PyArg_ParseTuple(args, "d", &timedouble))
+    int r;
+    Py_BEGIN_ALLOW_THREADS
+    r = sd_journal_seek_tail(self->j);
+    Py_END_ALLOW_THREADS
+    if (set_error(r, NULL, NULL))
         return NULL;
+    Py_RETURN_NONE;
+}
 
+
+PyDoc_STRVAR(Reader_seek_realtime__doc__,
+             "seek_realtime(realtime) -> None\n\n"
+             "Seek to nearest matching journal entry to `realtime`. Argument\n"
+             "`realtime` in specified in seconds.");
+static PyObject* Reader_seek_realtime(Reader *self, PyObject *args)
+{
     uint64_t timestamp;
-    timestamp = (uint64_t) (timedouble * 1.0E6);
+    int r;
 
-    if ((int64_t) timestamp < 0LL) {
-        PyErr_SetString(PyExc_ValueError, "Time must be positive integer");
+    if (!PyArg_ParseTuple(args, "K:seek_realtime", &timestamp))
         return NULL;
-    }
 
-    int r;
     Py_BEGIN_ALLOW_THREADS
     r = sd_journal_seek_realtime_usec(self->j, timestamp);
     Py_END_ALLOW_THREADS
-    if (r < 0) {
-        errno = -r;
-        PyErr_SetFromErrno(PyExc_OSError);
+    if (set_error(r, NULL, NULL))
         return NULL;
-    }
     Py_RETURN_NONE;
 }
 
-PyDoc_STRVAR(Journal_seek_monotonic__doc__,
-"seek_monotonic(monotonic[, bootid]) -> None\n\n"
-"Seek to nearest matching journal entry to `monotonic`. Argument\n"
-"`monotonic` is an timestamp from boot in seconds.\n"
-"Argument `bootid` is a string representing which boot the\n"
-"monotonic time is reference to. Defaults to current bootid.");
-static PyObject *
-Journal_seek_monotonic(Journal *self, PyObject *args)
-{
-    double timedouble;
-    char *bootid=NULL;
-    if (! PyArg_ParseTuple(args, "d|z", &timedouble, &bootid))
-        return NULL;
 
+PyDoc_STRVAR(Reader_seek_monotonic__doc__,
+             "seek_monotonic(monotonic[, bootid]) -> None\n\n"
+             "Seek to nearest matching journal entry to `monotonic`. Argument\n"
+             "`monotonic` is an timestamp from boot in microseconds.\n"
+             "Argument `bootid` is a string representing which boot the\n"
+             "monotonic time is reference to. Defaults to current bootid.");
+static PyObject* Reader_seek_monotonic(Reader *self, PyObject *args)
+{
+    char *bootid = NULL;
     uint64_t timestamp;
-    timestamp = (uint64_t) (timedouble * 1.0E6);
+    sd_id128_t id;
+    int r;
 
-    if ((int64_t) timestamp < 0LL) {
-        PyErr_SetString(PyExc_ValueError, "Time must be positive number");
+    if (!PyArg_ParseTuple(args, "K|z:seek_monotonic", &timestamp, &bootid))
         return NULL;
-    }
 
-    sd_id128_t sd_id;
-    int r;
     if (bootid) {
-        r = sd_id128_from_string(bootid, &sd_id);
-        if (r == -EINVAL) {
-            PyErr_SetString(PyExc_ValueError, "Invalid bootid");
-            return NULL;
-        }else if (r < 0) {
-            errno = -r;
-            PyErr_SetFromErrno(PyExc_OSError);
+        r = sd_id128_from_string(bootid, &id);
+        if (set_error(r, NULL, "Invalid bootid"))
             return NULL;
-        }
-    }else{
-        r = sd_id128_get_boot(&sd_id);
-        if (r == -EIO) {
-            PyErr_SetString(PyExc_IOError, "Error getting current boot ID");
-            return NULL;
-        }else if (r < 0) {
-            errno = -r;
-            PyErr_SetFromErrno(PyExc_OSError);
+    } else {
+        Py_BEGIN_ALLOW_THREADS
+        r = sd_id128_get_boot(&id);
+        Py_END_ALLOW_THREADS
+        if (set_error(r, NULL, NULL))
             return NULL;
-        }
     }
 
     Py_BEGIN_ALLOW_THREADS
-    r = sd_journal_seek_monotonic_usec(self->j, sd_id, timestamp);
+    r = sd_journal_seek_monotonic_usec(self->j, id, timestamp);
     Py_END_ALLOW_THREADS
-    if (r < 0) {
-        errno = -r;
-        PyErr_SetFromErrno(PyExc_OSError);
+    if (set_error(r, NULL, NULL))
         return NULL;
-    }
+
     Py_RETURN_NONE;
 }
-PyDoc_STRVAR(Journal_wait__doc__,
-"wait([timeout]) -> Change state (integer)\n\n"
-"Waits until there is a change in the journal. Argument `timeout`\n"
-"is the maximum number of seconds to wait before returning\n"
-"regardless if journal has changed. If `timeout` is not given or is\n"
-"0, then it will block forever.\n"
-"Will return constants: NOP if no change; APPEND if new\n"
-"entries have been added to the end of the journal; and\n"
-"INVALIDATE if journal files have been added or removed.");
-static PyObject *
-Journal_wait(Journal *self, PyObject *args, PyObject *keywds)
+
+
+PyDoc_STRVAR(Reader_process__doc__,
+             "process() -> state change (integer)\n\n"
+             "Process events and reset the readable state of the file\n"
+             "descriptor returned by .fileno().\n\n"
+             "Will return constants: NOP if no change; APPEND if new\n"
+             "entries have been added to the end of the journal; and\n"
+             "INVALIDATE if journal files have been added or removed.\n\n"
+             "See man:sd_journal_process(3) for further discussion.");
+static PyObject* Reader_process(Reader *self, PyObject *args)
 {
-    int64_t timeout=0LL;
-    if (! PyArg_ParseTuple(args, "|L", &timeout))
+    int r;
+
+    assert(!args);
+
+    Py_BEGIN_ALLOW_THREADS
+    r = sd_journal_process(self->j);
+    Py_END_ALLOW_THREADS
+    if (set_error(r, NULL, NULL) < 0)
         return NULL;
 
+    return long_FromLong(r);
+}
+
+
+PyDoc_STRVAR(Reader_wait__doc__,
+             "wait([timeout]) -> state change (integer)\n\n"
+             "Wait for a change in the journal. Argument `timeout` specifies\n"
+             "the maximum number of microseconds to wait before returning\n"
+             "regardless of wheter the journal has changed. If `timeout` is -1,\n"
+             "then block forever.\n\n"
+             "Will return constants: NOP if no change; APPEND if new\n"
+             "entries have been added to the end of the journal; and\n"
+             "INVALIDATE if journal files have been added or removed.\n\n"
+             "See man:sd_journal_wait(3) for further discussion.");
+static PyObject* Reader_wait(Reader *self, PyObject *args)
+{
     int r;
+    int64_t timeout;
+
+    if (!PyArg_ParseTuple(args, "|L:wait", &timeout))
+        return NULL;
+
     Py_BEGIN_ALLOW_THREADS
-    if ( timeout == 0LL) {
-        r = sd_journal_wait(self->j, (uint64_t) -1);
-    }else{
-        r = sd_journal_wait(self->j, timeout * 1E6);
-    }
+    r = sd_journal_wait(self->j, timeout);
     Py_END_ALLOW_THREADS
-    if (r < 0) {
-        errno = -r;
-        PyObject *errtype = r == -ENOMEM ? PyExc_MemoryError :
-                            PyExc_OSError;
-        PyErr_SetFromErrno(errtype);
+    if (set_error(r, NULL, NULL) < 0)
         return NULL;
-    }
-#if PY_MAJOR_VERSION >=3
-    return PyLong_FromLong(r);
-#else
-    return PyInt_FromLong(r);
-#endif
+
+    return long_FromLong(r);
 }
 
-PyDoc_STRVAR(Journal_seek_cursor__doc__,
-"seek_cursor(cursor) -> None\n\n"
-"Seeks to journal entry by given unique reference `cursor`.");
-static PyObject *
-Journal_seek_cursor(Journal *self, PyObject *args)
+
+PyDoc_STRVAR(Reader_seek_cursor__doc__,
+             "seek_cursor(cursor) -> None\n\n"
+             "Seek to journal entry by given unique reference `cursor`.");
+static PyObject* Reader_seek_cursor(Reader *self, PyObject *args)
 {
     const char *cursor;
-    if (! PyArg_ParseTuple(args, "s", &cursor))
+    int r;
+
+    if (!PyArg_ParseTuple(args, "s:seek_cursor", &cursor))
         return NULL;
 
-    int r;
     Py_BEGIN_ALLOW_THREADS
     r = sd_journal_seek_cursor(self->j, cursor);
     Py_END_ALLOW_THREADS
-    if (r < 0) {
-        errno = -r;
-        PyObject *errtype = r == -EINVAL ? PyExc_ValueError :
-                            r == -ENOMEM ? PyExc_MemoryError :
-                            PyExc_OSError;
-        PyErr_SetFromErrno(errtype);
+    if (set_error(r, NULL, "Invalid cursor"))
         return NULL;
-    }
     Py_RETURN_NONE;
 }
 
-static PyObject *
-Journal_iter(PyObject *self)
+
+PyDoc_STRVAR(Reader_get_cursor__doc__,
+             "get_cursor() -> str\n\n"
+             "Return a cursor string for the current journal entry.\n\n"
+             "Wraps sd_journal_get_cursor(). See man:sd_journal_get_cursor(3).");
+static PyObject* Reader_get_cursor(Reader *self, PyObject *args)
 {
-    Py_INCREF(self);
-    return self;
+    _cleanup_free_ char *cursor = NULL;
+    int r;
+
+    assert(self);
+    assert(!args);
+
+    r = sd_journal_get_cursor(self->j, &cursor);
+    if (set_error(r, NULL, NULL))
+        return NULL;
+
+    return unicode_FromString(cursor);
 }
 
-static PyObject *
-Journal_iternext(PyObject *self)
+
+PyDoc_STRVAR(Reader_test_cursor__doc__,
+             "test_cursor(str) -> bool\n\n"
+             "Test whether the cursor string matches current journal entry.\n\n"
+             "Wraps sd_journal_test_cursor(). See man:sd_journal_test_cursor(3).");
+static PyObject* Reader_test_cursor(Reader *self, PyObject *args)
 {
-    PyObject *dict;
-    Py_ssize_t dict_size;
+    const char *cursor;
+    int r;
+
+    assert(self);
+    assert(args);
 
-    dict = PyObject_CallMethod(self, "get_next", "");
-    dict_size = PyDict_Size(dict);
-    if ((int64_t) dict_size > 0LL) {
-        return dict;
-    }else{
-        Py_DECREF(dict);
-        PyErr_SetNone(PyExc_StopIteration);
+    if (!PyArg_ParseTuple(args, "s:test_cursor", &cursor))
         return NULL;
-    }
+
+    r = sd_journal_test_cursor(self->j, cursor);
+    set_error(r, NULL, NULL);
+    if (r < 0)
+        return NULL;
+
+    return PyBool_FromLong(r);
 }
 
-PyDoc_STRVAR(Journal_query_unique__doc__,
-"query_unique(field) -> a set of values\n\n"
-"Returns a set of unique values in journal for given `field`.\n"
-"Note this does not respect any journal matches.");
-static PyObject *
-Journal_query_unique(Journal *self, PyObject *args)
+PyDoc_STRVAR(Reader_query_unique__doc__,
+             "query_unique(field) -> a set of values\n\n"
+             "Return a set of unique values appearing in journal for the\n"
+             "given `field`. Note this does not respect any journal matches.");
+static PyObject* Reader_query_unique(Reader *self, PyObject *args)
 {
     char *query;
-    if (! PyArg_ParseTuple(args, "s", &query))
+    int r;
+    const void *uniq;
+    size_t uniq_len;
+    PyObject *value_set, *key, *value;
+
+    if (!PyArg_ParseTuple(args, "s:query_unique", &query))
         return NULL;
 
-    int r;
     Py_BEGIN_ALLOW_THREADS
     r = sd_journal_query_unique(self->j, query);
     Py_END_ALLOW_THREADS
-    if (r < 0) {
-        errno = -r;
-        PyObject *errtype = r == -EINVAL ? PyExc_ValueError :
-                            r == -ENOMEM ? PyExc_MemoryError :
-                            PyExc_OSError;
-        PyErr_SetFromErrno(errtype);
+    if (set_error(r, NULL, "Invalid field name"))
         return NULL;
-    }
 
-    const void *uniq;
-    size_t uniq_len;
-    const char *delim_ptr;
-    PyObject *value_set, *key, *value;
     value_set = PySet_New(0);
-
-#if PY_MAJOR_VERSION >=3
-    key = PyUnicode_FromString(query);
-#else
-    key = PyString_FromString(query);
-#endif
+    key = unicode_FromString(query);
 
     SD_JOURNAL_FOREACH_UNIQUE(self->j, uniq, uniq_len) {
+        const char *delim_ptr;
+
         delim_ptr = memchr(uniq, '=', uniq_len);
-        value = PyBytes_FromStringAndSize(delim_ptr + 1, (const char*) uniq + uniq_len - (delim_ptr + 1));
+        value = PyBytes_FromStringAndSize(
+            delim_ptr + 1,
+            (const char*) uniq + uniq_len - (delim_ptr + 1));
         PySet_Add(value_set, value);
         Py_DECREF(value);
     }
@@ -554,155 +883,214 @@ Journal_query_unique(Journal *self, PyObject *args)
     return value_set;
 }
 
-static PyObject *
-Journal_get_data_threshold(Journal *self, void *closure)
+
+PyDoc_STRVAR(Reader_get_catalog__doc__,
+             "get_catalog() -> str\n\n"
+             "Retrieve a message catalog entry for the current journal entry.\n"
+             "Will throw IndexError if the entry has no MESSAGE_ID\n"
+             "and KeyError is the id is specified, but hasn't been found\n"
+             "in the catalog.\n\n"
+             "Wraps man:sd_journal_get_catalog(3).");
+static PyObject* Reader_get_catalog(Reader *self, PyObject *args)
+{
+    int r;
+    _cleanup_free_ char *msg = NULL;
+
+    assert(self);
+    assert(!args);
+
+    Py_BEGIN_ALLOW_THREADS
+    r = sd_journal_get_catalog(self->j, &msg);
+    Py_END_ALLOW_THREADS
+    if (r == -ENOENT) {
+        const void* mid;
+        size_t mid_len;
+
+        r = sd_journal_get_data(self->j, "MESSAGE_ID", &mid, &mid_len);
+        if (r == 0) {
+            const size_t l = sizeof("MESSAGE_ID");
+            assert(mid_len > l);
+            PyErr_Format(PyExc_KeyError, "%.*s", (int) (mid_len - l),
+                         (const char*) mid + l);
+        } else if (r == -ENOENT)
+            PyErr_SetString(PyExc_IndexError, "no MESSAGE_ID field");
+        else
+            set_error(r, NULL, NULL);
+        return NULL;
+    } else if (set_error(r, NULL, NULL))
+        return NULL;
+
+    return unicode_FromString(msg);
+}
+
+
+PyDoc_STRVAR(get_catalog__doc__,
+             "get_catalog(id128) -> str\n\n"
+             "Retrieve a message catalog entry for the given id.\n"
+             "Wraps man:sd_journal_get_catalog_for_message_id(3).");
+static PyObject* get_catalog(PyObject *self, PyObject *args)
+{
+    int r;
+    char *id_ = NULL;
+    sd_id128_t id;
+    _cleanup_free_ char *msg = NULL;
+
+    assert(!self);
+    assert(args);
+
+    if (!PyArg_ParseTuple(args, "z:get_catalog", &id_))
+        return NULL;
+
+    r = sd_id128_from_string(id_, &id);
+    if (set_error(r, NULL, "Invalid id128"))
+        return NULL;
+
+    Py_BEGIN_ALLOW_THREADS
+    r = sd_journal_get_catalog_for_message_id(id, &msg);
+    Py_END_ALLOW_THREADS
+    if (set_error(r, NULL, NULL))
+        return NULL;
+
+    return unicode_FromString(msg);
+}
+
+
+PyDoc_STRVAR(data_threshold__doc__,
+             "Threshold for field size truncation in bytes.\n\n"
+             "Fields longer than this will be truncated to the threshold size.\n"
+             "Defaults to 64Kb.");
+
+static PyObject* Reader_get_data_threshold(Reader *self, void *closure)
 {
     size_t cvalue;
-    PyObject *value;
     int r;
 
     r = sd_journal_get_data_threshold(self->j, &cvalue);
-    if (r < 0) {
-        errno = -r;
-        PyErr_SetFromErrno(PyExc_OSError);
+    if (set_error(r, NULL, NULL))
         return NULL;
-    }
 
-#if PY_MAJOR_VERSION >=3
-    value = PyLong_FromSize_t(cvalue);
-#else
-    value = PyInt_FromSize_t(cvalue);
-#endif
-    return value;
+    return long_FromSize_t(cvalue);
 }
 
-static int
-Journal_set_data_threshold(Journal *self, PyObject *value, void *closure)
+static int Reader_set_data_threshold(Reader *self, PyObject *value, void *closure)
 {
+    int r;
     if (value == NULL) {
-        PyErr_SetString(PyExc_TypeError, "Cannot delete data threshold");
+        PyErr_SetString(PyExc_AttributeError, "Cannot delete data threshold");
         return -1;
     }
-#if PY_MAJOR_VERSION >=3
-    if (! PyLong_Check(value)){
-#else
-    if (! PyInt_Check(value)){
-#endif
-        PyErr_SetString(PyExc_TypeError, "Data threshold must be int");
-        return -1;
-    }
-    int r;
-#if PY_MAJOR_VERSION >=3
-    r = sd_journal_set_data_threshold(self->j, (size_t) PyLong_AsLong(value));
-#else
-    r = sd_journal_set_data_threshold(self->j, (size_t) PyInt_AsLong(value));
-#endif
-    if (r < 0) {
-        errno = -r;
-        PyErr_SetFromErrno(PyExc_OSError);
+    if (!long_Check(value)){
+        PyErr_SetString(PyExc_TypeError, "Data threshold must be an int");
         return -1;
     }
-    return 0;
+    r = sd_journal_set_data_threshold(self->j, (size_t) long_AsLong(value));
+    return set_error(r, NULL, NULL);
+}
+
+
+PyDoc_STRVAR(closed__doc__,
+             "True iff journal is closed");
+static PyObject* Reader_get_closed(Reader *self, void *closure)
+{
+    return PyBool_FromLong(self->j == NULL);
 }
 
-static PyGetSetDef Journal_getseters[] = {
-    {"data_threshold",
-    (getter)Journal_get_data_threshold,
-    (setter)Journal_set_data_threshold,
-    "data threshold",
-    NULL},
-    {NULL}
+
+static PyGetSetDef Reader_getsetters[] = {
+    {(char*) "data_threshold",
+     (getter) Reader_get_data_threshold,
+     (setter) Reader_set_data_threshold,
+     (char*) data_threshold__doc__,
+     NULL},
+    {(char*) "closed",
+     (getter) Reader_get_closed,
+     NULL,
+     (char*) closed__doc__,
+     NULL},
+    {} /* Sentinel */
 };
 
-static PyMethodDef Journal_methods[] = {
-    {"get_next", (PyCFunction)Journal_get_next, METH_VARARGS,
-    Journal_get_next__doc__},
-    {"get_previous", (PyCFunction)Journal_get_previous, METH_VARARGS,
-    Journal_get_previous__doc__},
-    {"add_match", (PyCFunction)Journal_add_match, METH_VARARGS|METH_KEYWORDS,
-    Journal_add_match__doc__},
-    {"add_disjunction", (PyCFunction)Journal_add_disjunction, METH_NOARGS,
-    Journal_add_disjunction__doc__},
-    {"flush_matches", (PyCFunction)Journal_flush_matches, METH_NOARGS,
-    Journal_flush_matches__doc__},
-    {"seek", (PyCFunction)Journal_seek, METH_VARARGS | METH_KEYWORDS,
-    Journal_seek__doc__},
-    {"seek_realtime", (PyCFunction)Journal_seek_realtime, METH_VARARGS,
-    Journal_seek_realtime__doc__},
-    {"seek_monotonic", (PyCFunction)Journal_seek_monotonic, METH_VARARGS,
-    Journal_seek_monotonic__doc__},
-    {"wait", (PyCFunction)Journal_wait, METH_VARARGS,
-    Journal_wait__doc__},
-    {"seek_cursor", (PyCFunction)Journal_seek_cursor, METH_VARARGS,
-    Journal_seek_cursor__doc__},
-    {"query_unique", (PyCFunction)Journal_query_unique, METH_VARARGS,
-    Journal_query_unique__doc__},
-    {NULL}  /* Sentinel */
+static PyMethodDef Reader_methods[] = {
+    {"fileno",          (PyCFunction) Reader_fileno, METH_NOARGS, Reader_fileno__doc__},
+    {"reliable_fd",     (PyCFunction) Reader_reliable_fd, METH_NOARGS, Reader_reliable_fd__doc__},
+    {"get_events",      (PyCFunction) Reader_get_events, METH_NOARGS, Reader_get_events__doc__},
+    {"get_timeout",     (PyCFunction) Reader_get_timeout, METH_NOARGS, Reader_get_timeout__doc__},
+    {"get_timeout_ms",  (PyCFunction) Reader_get_timeout_ms, METH_NOARGS, Reader_get_timeout_ms__doc__},
+    {"close",           (PyCFunction) Reader_close, METH_NOARGS, Reader_close__doc__},
+    {"get_usage",       (PyCFunction) Reader_get_usage, METH_NOARGS, Reader_get_usage__doc__},
+    {"__enter__",       (PyCFunction) Reader___enter__, METH_NOARGS, Reader___enter____doc__},
+    {"__exit__",        (PyCFunction) Reader___exit__, METH_VARARGS, Reader___exit____doc__},
+    {"_next",           (PyCFunction) Reader_next, METH_VARARGS, Reader_next__doc__},
+    {"_previous",       (PyCFunction) Reader_previous, METH_VARARGS, Reader_previous__doc__},
+    {"_get",            (PyCFunction) Reader_get, METH_VARARGS, Reader_get__doc__},
+    {"_get_all",        (PyCFunction) Reader_get_all, METH_NOARGS, Reader_get_all__doc__},
+    {"_get_realtime",   (PyCFunction) Reader_get_realtime, METH_NOARGS, Reader_get_realtime__doc__},
+    {"_get_monotonic",  (PyCFunction) Reader_get_monotonic, METH_NOARGS, Reader_get_monotonic__doc__},
+    {"add_match",       (PyCFunction) Reader_add_match, METH_VARARGS|METH_KEYWORDS, Reader_add_match__doc__},
+    {"add_disjunction", (PyCFunction) Reader_add_disjunction, METH_NOARGS, Reader_add_disjunction__doc__},
+    {"add_conjunction", (PyCFunction) Reader_add_conjunction, METH_NOARGS, Reader_add_conjunction__doc__},
+    {"flush_matches",   (PyCFunction) Reader_flush_matches, METH_NOARGS, Reader_flush_matches__doc__},
+    {"seek_head",       (PyCFunction) Reader_seek_head, METH_NOARGS, Reader_seek_head__doc__},
+    {"seek_tail",       (PyCFunction) Reader_seek_tail, METH_NOARGS, Reader_seek_tail__doc__},
+    {"seek_realtime",   (PyCFunction) Reader_seek_realtime, METH_VARARGS, Reader_seek_realtime__doc__},
+    {"seek_monotonic",  (PyCFunction) Reader_seek_monotonic, METH_VARARGS, Reader_seek_monotonic__doc__},
+    {"process",         (PyCFunction) Reader_process, METH_NOARGS, Reader_process__doc__},
+    {"wait",            (PyCFunction) Reader_wait, METH_VARARGS, Reader_wait__doc__},
+    {"seek_cursor",     (PyCFunction) Reader_seek_cursor, METH_VARARGS, Reader_seek_cursor__doc__},
+    {"_get_cursor",     (PyCFunction) Reader_get_cursor, METH_NOARGS, Reader_get_cursor__doc__},
+    {"test_cursor",     (PyCFunction) Reader_test_cursor, METH_VARARGS, Reader_test_cursor__doc__},
+    {"query_unique",    (PyCFunction) Reader_query_unique, METH_VARARGS, Reader_query_unique__doc__},
+    {"get_catalog",     (PyCFunction) Reader_get_catalog, METH_NOARGS, Reader_get_catalog__doc__},
+    {}  /* Sentinel */
 };
 
-static PyTypeObject JournalType = {
+static PyTypeObject ReaderType = {
     PyVarObject_HEAD_INIT(NULL, 0)
-    "_reader.Journal",           /*tp_name*/
-    sizeof(Journal),                  /*tp_basicsize*/
-    0,                                /*tp_itemsize*/
-    (destructor)Journal_dealloc,      /*tp_dealloc*/
-    0,                                /*tp_print*/
-    0,                                /*tp_getattr*/
-    0,                                /*tp_setattr*/
-    0,                                /*tp_compare*/
-    0,                                /*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*/
-    Journal__doc__,                   /* tp_doc */
-    0,                                /* tp_traverse */
-    0,                                /* tp_clear */
-    0,                                /* tp_richcompare */
-    0,                                /* tp_weaklistoffset */
-    Journal_iter,                     /* tp_iter */
-    Journal_iternext,                 /* tp_iternext */
-    Journal_methods,                  /* tp_methods */
-    0,                                /* tp_members */
-    Journal_getseters,                /* tp_getset */
-    0,                                /* tp_base */
-    0,                                /* tp_dict */
-    0,                                /* tp_descr_get */
-    0,                                /* tp_descr_set */
-    0,                                /* tp_dictoffset */
-    (initproc)Journal_init,           /* tp_init */
-    0,                                /* tp_alloc */
-    PyType_GenericNew,                /* tp_new */
+    .tp_name = "_reader._Reader",
+    .tp_basicsize = sizeof(Reader),
+    .tp_dealloc = (destructor) Reader_dealloc,
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+    .tp_doc = Reader__doc__,
+    .tp_methods = Reader_methods,
+    .tp_getset = Reader_getsetters,
+    .tp_init = (initproc) Reader_init,
+    .tp_new = PyType_GenericNew,
+};
+
+static PyMethodDef methods[] = {
+        { "_get_catalog", get_catalog, METH_VARARGS, get_catalog__doc__},
+        {} /* Sentinel */
 };
 
 #if PY_MAJOR_VERSION >= 3
-static PyModuleDef _reader_module = {
+static PyModuleDef module = {
     PyModuleDef_HEAD_INIT,
     "_reader",
-    "Module that reads systemd journal similar to journalctl.",
+    module__doc__,
     -1,
-    NULL, NULL, NULL, NULL, NULL
+    methods,
 };
 #endif
 
+#if PY_MAJOR_VERSION >= 3
+static bool initialized = false;
+#endif
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-prototypes"
+
 PyMODINIT_FUNC
 #if PY_MAJOR_VERSION >= 3
 PyInit__reader(void)
 #else
-init_reader(void) 
+init_reader(void)
 #endif
 {
     PyObject* m;
 
     PyDateTime_IMPORT;
 
-    if (PyType_Ready(&JournalType) < 0)
+    if (PyType_Ready(&ReaderType) < 0)
 #if PY_MAJOR_VERSION >= 3
         return NULL;
 #else
@@ -710,26 +1098,46 @@ init_reader(void)
 #endif
 
 #if PY_MAJOR_VERSION >= 3
-    m = PyModule_Create(&_reader_module);
+    m = PyModule_Create(&module);
     if (m == NULL)
         return NULL;
+
+    if (!initialized) {
+        PyStructSequence_InitType(&MonotonicType, &Monotonic_desc);
+        initialized = true;
+    }
 #else
-    m = Py_InitModule3("_reader", NULL,
-                   "Module that reads systemd journal similar to journalctl.");
+    m = Py_InitModule3("_reader", methods, module__doc__);
     if (m == NULL)
         return;
 #endif
 
-    Py_INCREF(&JournalType);
-    PyModule_AddObject(m, "_Journal", (PyObject *)&JournalType);
-    PyModule_AddIntConstant(m, "NOP", SD_JOURNAL_NOP);
-    PyModule_AddIntConstant(m, "APPEND", SD_JOURNAL_APPEND);
-    PyModule_AddIntConstant(m, "INVALIDATE", SD_JOURNAL_INVALIDATE);
-    PyModule_AddIntConstant(m, "LOCAL_ONLY", SD_JOURNAL_LOCAL_ONLY);
-    PyModule_AddIntConstant(m, "RUNTIME_ONLY", SD_JOURNAL_RUNTIME_ONLY);
-    PyModule_AddIntConstant(m, "SYSTEM_ONLY", SD_JOURNAL_SYSTEM_ONLY);
+    Py_INCREF(&ReaderType);
+#if PY_MAJOR_VERSION >= 3
+    Py_INCREF(&MonotonicType);
+#endif
+    if (PyModule_AddObject(m, "_Reader", (PyObject *) &ReaderType) ||
+#if PY_MAJOR_VERSION >= 3
+        PyModule_AddObject(m, "Monotonic", (PyObject*) &MonotonicType) ||
+#endif
+        PyModule_AddIntConstant(m, "NOP", SD_JOURNAL_NOP) ||
+        PyModule_AddIntConstant(m, "APPEND", SD_JOURNAL_APPEND) ||
+        PyModule_AddIntConstant(m, "INVALIDATE", SD_JOURNAL_INVALIDATE) ||
+        PyModule_AddIntConstant(m, "LOCAL_ONLY", SD_JOURNAL_LOCAL_ONLY) ||
+        PyModule_AddIntConstant(m, "RUNTIME_ONLY", SD_JOURNAL_RUNTIME_ONLY) ||
+        PyModule_AddIntConstant(m, "SYSTEM", SD_JOURNAL_SYSTEM) ||
+        PyModule_AddIntConstant(m, "SYSTEM_ONLY", SD_JOURNAL_SYSTEM_ONLY) ||
+        PyModule_AddIntConstant(m, "CURRENT_USER", SD_JOURNAL_CURRENT_USER) ||
+        PyModule_AddStringConstant(m, "__version__", PACKAGE_VERSION)) {
+#if PY_MAJOR_VERSION >= 3
+        Py_DECREF(m);
+        return NULL;
+#endif
+    }
 
 #if PY_MAJOR_VERSION >= 3
     return m;
 #endif
 }
+
+#pragma GCC diagnostic pop