gps-serial-port: new type to handle read-only serial ports with GPS traces

src/Makefile.am

@@ -70,7 +70,9 @@ libserial_la_SOURCES = \
 	mm-at-serial-port.c \
 	mm-at-serial-port.h \
 	mm-qcdm-serial-port.c \
-	mm-qcdm-serial-port.h
+	mm-qcdm-serial-port.h \
+	mm-gps-serial-port.c \
+	mm-gps-serial-port.h
 
 # Daemon specific enum types
 DAEMON_ENUMS = \

src/mm-gps-serial-port.c

@@ -0,0 +1,218 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2012 Aleksander Morgado <aleksander@gnu.org>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "mm-gps-serial-port.h"
+#include "mm-log.h"
+
+G_DEFINE_TYPE (MMGpsSerialPort, mm_gps_serial_port, MM_TYPE_SERIAL_PORT)
+
+struct _MMGpsSerialPortPrivate {
+    /* Trace handler data */
+    MMGpsSerialTraceFn callback;
+    gpointer user_data;
+    GDestroyNotify notify;
+
+    /* Regex for all known traces */
+    GRegex *known_traces_regex;
+};
+
+/*****************************************************************************/
+
+void
+mm_gps_serial_port_add_trace_handler (MMGpsSerialPort *self,
+                                      MMGpsSerialTraceFn callback,
+                                      gpointer user_data,
+                                      GDestroyNotify notify)
+{
+    g_return_if_fail (MM_IS_GPS_SERIAL_PORT (self));
+
+    if (self->priv->notify)
+        self->priv->notify (self->priv->user_data);
+
+    self->priv->callback = callback;
+    self->priv->user_data = user_data;
+    self->priv->notify = notify;
+}
+
+/*****************************************************************************/
+
+static gboolean
+remove_eval_cb (const GMatchInfo *match_info,
+                GString *result,
+                gpointer user_data)
+{
+    int *result_len = (int *) user_data;
+    int start;
+    int end;
+
+    if (g_match_info_fetch_pos  (match_info, 0, &start, &end))
+        *result_len -= (end - start);
+
+    return FALSE;
+}
+
+static gboolean
+parse_response (MMSerialPort *port,
+                GByteArray *response,
+                GError **error)
+{
+    MMGpsSerialPort *self = MM_GPS_SERIAL_PORT (port);
+    gboolean matches;
+    GMatchInfo *match_info;
+    gchar *str;
+    gint result_len;
+    guint i;
+
+    for (i = 0; i < response->len; i++) {
+        /* If there is any content before the first $,
+         * assume it's garbage, and skip it */
+        if (response->data[i] == '$') {
+            if (i > 0)
+                g_byte_array_remove_range (response, 0, i);
+            /* else, good, we're already started with $ */
+            break;
+        }
+    }
+
+    matches = g_regex_match_full (self->priv->known_traces_regex,
+                                  (const gchar *) response->data,
+                                  response->len,
+                                  0, 0, &match_info, NULL);
+
+    if (self->priv->callback) {
+        while (g_match_info_matches (match_info)) {
+            gchar *trace;
+
+            trace = g_match_info_fetch (match_info, 0);
+            if (trace) {
+                self->priv->callback (self, trace, self->priv->user_data);
+                g_free (trace);
+            }
+            g_match_info_next (match_info, NULL);
+        }
+    }
+
+    g_match_info_free (match_info);
+
+    if (!matches)
+        return FALSE;
+
+    /* Remove matches */
+    result_len = response->len;
+    str = g_regex_replace_eval (self->priv->known_traces_regex,
+                                (const char *) response->data,
+                                response->len,
+                                0, 0,
+                                remove_eval_cb, &result_len, NULL);
+
+    g_byte_array_remove_range (response, 0, response->len);
+    g_byte_array_append (response, (const guint8 *) str, result_len);
+    g_free (str);
+
+    return TRUE;
+}
+
+/*****************************************************************************/
+
+static void
+debug_log (MMSerialPort *port, const char *prefix, const char *buf, gsize len)
+{
+    static GString *debug = NULL;
+    const char *s;
+
+    if (!debug)
+        debug = g_string_sized_new (256);
+
+    g_string_append (debug, prefix);
+    g_string_append (debug, " '");
+
+    s = buf;
+    while (len--) {
+        if (g_ascii_isprint (*s))
+            g_string_append_c (debug, *s);
+        else if (*s == '\r')
+            g_string_append (debug, "<CR>");
+        else if (*s == '\n')
+            g_string_append (debug, "<LF>");
+        else
+            g_string_append_printf (debug, "\\%u", (guint8) (*s & 0xFF));
+
+        s++;
+    }
+
+    g_string_append_c (debug, '\'');
+    mm_dbg ("(%s): %s", mm_port_get_device (MM_PORT (port)), debug->str);
+    g_string_truncate (debug, 0);
+}
+
+/*****************************************************************************/
+
+MMGpsSerialPort *
+mm_gps_serial_port_new (const char *name)
+{
+    return MM_GPS_SERIAL_PORT (g_object_new (MM_TYPE_GPS_SERIAL_PORT,
+                                             MM_PORT_DEVICE, name,
+                                             MM_PORT_SUBSYS, MM_PORT_SUBSYS_TTY,
+                                             MM_PORT_TYPE, MM_PORT_TYPE_GPS,
+                                             NULL));
+}
+
+static void
+mm_gps_serial_port_init (MMGpsSerialPort *self)
+{
+    self->priv = G_TYPE_INSTANCE_GET_PRIVATE ((self),
+                                              MM_TYPE_GPS_SERIAL_PORT,
+                                              MMGpsSerialPortPrivate);
+
+    /* We'll assume that all traces start with the dollar sign and end with \r\n */
+    self->priv->known_traces_regex =
+        g_regex_new ("\\$.*\\r\\n",
+                     G_REGEX_RAW | G_REGEX_OPTIMIZE,
+                     0,
+                     NULL);
+}
+
+static void
+finalize (GObject *object)
+{
+    MMGpsSerialPort *self = MM_GPS_SERIAL_PORT (object);
+
+    if (self->priv->notify)
+        self->priv->notify (self->priv->user_data);
+
+    g_regex_unref (self->priv->known_traces_regex);
+
+    G_OBJECT_CLASS (mm_gps_serial_port_parent_class)->finalize (object);
+}
+
+static void
+mm_gps_serial_port_class_init (MMGpsSerialPortClass *klass)
+{
+    GObjectClass *object_class = G_OBJECT_CLASS (klass);
+    MMSerialPortClass *port_class = MM_SERIAL_PORT_CLASS (klass);
+
+    g_type_class_add_private (object_class, sizeof (MMGpsSerialPortPrivate));
+
+    /* Virtual methods */
+    object_class->finalize = finalize;
+
+    port_class->parse_response = parse_response;
+    port_class->debug_log = debug_log;
+}

src/mm-gps-serial-port.h

@@ -0,0 +1,57 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2012 - Aleksander Morgado <aleksander@gnu.org>
+ */
+
+#ifndef MM_GPS_SERIAL_PORT_H
+#define MM_GPS_SERIAL_PORT_H
+
+#include <glib.h>
+#include <glib-object.h>
+
+#include "mm-serial-port.h"
+
+#define MM_TYPE_GPS_SERIAL_PORT            (mm_gps_serial_port_get_type ())
+#define MM_GPS_SERIAL_PORT(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), MM_TYPE_GPS_SERIAL_PORT, MMGpsSerialPort))
+#define MM_GPS_SERIAL_PORT_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  MM_TYPE_GPS_SERIAL_PORT, MMGpsSerialPortClass))
+#define MM_IS_GPS_SERIAL_PORT(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MM_TYPE_GPS_SERIAL_PORT))
+#define MM_IS_GPS_SERIAL_PORT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  MM_TYPE_GPS_SERIAL_PORT))
+#define MM_GPS_SERIAL_PORT_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  MM_TYPE_GPS_SERIAL_PORT, MMGpsSerialPortClass))
+
+typedef struct _MMGpsSerialPort MMGpsSerialPort;
+typedef struct _MMGpsSerialPortClass MMGpsSerialPortClass;
+typedef struct _MMGpsSerialPortPrivate MMGpsSerialPortPrivate;
+
+typedef void (*MMGpsSerialTraceFn) (MMGpsSerialPort *port,
+                                    const gchar *trace,
+                                    gpointer user_data);
+
+struct _MMGpsSerialPort {
+    MMSerialPort parent;
+    MMGpsSerialPortPrivate *priv;
+};
+
+struct _MMGpsSerialPortClass {
+    MMSerialPortClass parent;
+};
+
+GType mm_gps_serial_port_get_type (void);
+
+MMGpsSerialPort *mm_gps_serial_port_new (const char *name);
+
+void mm_gps_serial_port_add_trace_handler (MMGpsSerialPort *self,
+                                           MMGpsSerialTraceFn callback,
+                                           gpointer user_data,
+                                           GDestroyNotify notify);
+
+#endif /* MM_GPS_SERIAL_PORT_H */