libmm-common: new helper key/value parser

libmm-common/mm-common-helpers.c

@@ -10,9 +10,10 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details:
  *
- * Copyright (C) 2011 - Google, Inc.
+ * Copyright (C) 2011 - 2012 Google, Inc.
  */
 
+#include <string.h>
 #include <gio/gio.h>
 
 #include <ModemManager.h>
@@ -314,3 +315,145 @@ mm_common_build_bands_any (void)
                                  g_variant_new_uint32 (MM_MODEM_BAND_ANY));
     return g_variant_builder_end (&builder);
 }
+
+/* Expecting input as:
+ *   key1=string,key2=true,key3=false...
+ * Strings may also be passed enclosed between double or single quotes, like:
+ *   key1="this is a string", key2='and so is this'
+ */
+gboolean
+mm_common_parse_key_value_string (const gchar *str,
+                                  GError **error,
+                                  MMParseKeyValueForeachFn callback,
+                                  gpointer user_data)
+{
+    GError *inner_error = NULL;
+    gchar *dup, *p, *key, *key_end, *value, *value_end, quote;
+
+    g_return_val_if_fail (callback != NULL, FALSE);
+    g_return_val_if_fail (str != NULL, FALSE);
+
+    dup = g_strdup (str);
+
+    p = dup;
+
+    while (TRUE) {
+        gboolean keep_iteration = FALSE;
+
+        /* Skip leading spaces */
+        while (*p && g_ascii_isspace (*p))
+            p++;
+
+        /* Key start */
+        key = p;
+        if (!g_ascii_isalnum (*key)) {
+            inner_error = g_error_new (MM_CORE_ERROR,
+                                       MM_CORE_ERROR_FAILED,
+                                       "Key must start with alpha/num, starts with '%c'",
+                                       *key);
+            break;
+        }
+
+        /* Key end */
+        while (g_ascii_isalnum (*p) || (*p == '-') || (*p == '_'))
+            p++;
+        key_end = p;
+        if (key_end == key) {
+            inner_error = g_error_new (MM_CORE_ERROR,
+                                       MM_CORE_ERROR_FAILED,
+                                       "Couldn't find a proper key");
+            break;
+        }
+
+        /* Skip whitespaces, if any */
+        while (*p && g_ascii_isspace (*p))
+            p++;
+
+        /* Equal sign must be here */
+        if (*p != '=') {
+            inner_error = g_error_new (MM_CORE_ERROR,
+                                       MM_CORE_ERROR_FAILED,
+                                       "Couldn't find equal sign separator");
+            break;
+        }
+        /* Skip the equal */
+        p++;
+
+        /* Skip whitespaces, if any */
+        while (*p && g_ascii_isspace (*p))
+            p++;
+
+        /* Do we have a quote-enclosed string? */
+        if (*p == '\"' || *p == '\'') {
+            quote = *p;
+            /* Skip the quote */
+            p++;
+            /* Value start */
+            value = p;
+            /* Find the closing quote */
+            p = strchr (p, quote);
+            if (!p) {
+                inner_error = g_error_new (MM_CORE_ERROR,
+                                           MM_CORE_ERROR_FAILED,
+                                           "Unmatched quotes in string value");
+                break;
+            }
+
+            /* Value end */
+            value_end = p;
+            /* Skip the quote */
+            p++;
+        } else {
+            /* Value start */
+            value = p;
+
+            /* Value end */
+            while ((*p != ',') && (*p != '\0') && !g_ascii_isspace (*p))
+                p++;
+            value_end = p;
+        }
+
+        /* Note that we allow value == value_end here */
+
+        /* Skip whitespaces, if any */
+        while (*p && g_ascii_isspace (*p))
+            p++;
+
+        /* If a comma is found, we should keep the iteration */
+        if (*p == ',') {
+            /* skip the comma */
+            p++;
+            keep_iteration = TRUE;
+        }
+
+        /* Got key and value, prepare them and run the callback */
+        *value_end = '\0';
+        *key_end = '\0';
+        if (!callback (key, value, user_data)) {
+            /* We were told to abort */
+            break;
+        }
+
+        if (keep_iteration)
+            continue;
+
+        /* Check if no more key/value pairs expected */
+        if (*p == '\0')
+            break;
+
+        inner_error = g_error_new (MM_CORE_ERROR,
+                                   MM_CORE_ERROR_FAILED,
+                                   "Unexpected content (%s) after value",
+                                   p);
+        break;
+    }
+
+    g_free (dup);
+
+    if (inner_error) {
+        g_propagate_error (error, inner_error);
+        return FALSE;
+    }
+
+    return TRUE;
+}

libmm-common/mm-common-helpers.h

@@ -46,4 +46,13 @@ GVariant    *mm_common_bands_garray_to_variant (GArray *array);
 GVariant    *mm_common_build_bands_any     (void);
 GVariant    *mm_common_build_bands_unknown (void);
 
+typedef gboolean (*MMParseKeyValueForeachFn) (const gchar *key,
+                                              const gchar *value,
+                                              gpointer user_data);
+gboolean mm_common_parse_key_value_string (const gchar *str,
+                                           GError **error,
+                                           MMParseKeyValueForeachFn callback,
+                                           gpointer user_data);
+
+
 #endif /* MM_COMMON_HELPERS_H */