introduce setting_param_new, setting_param_new_from_data and setting_param_free

gdigi.c

@@ -403,6 +403,92 @@ void append_value(GString *msg, guint value)
     }
 }
 
+/**
+ *  \param str pointer to value to unpack
+ *  \param len return location for how many bytes value is encoded on (length is added to current value)
+ *
+ *  Unpacks value using scheme used on all newer DigiTech products.
+ *
+ *  \return unpacked value
+ **/
+guint unpack_value(gchar *str, int *len)
+{
+    guint value;
+    gint tmp;
+
+    value = (unsigned char)str[0];
+    *len += 1;
+
+    if (value > 0x80) {
+        tmp = value & 0x7F;
+        value = 0;
+        gint i;
+        for (i = 0; i<tmp; i++) {
+            value |= ((unsigned char)str[1+i] << (8*(tmp-i-1)));
+        }
+        *len += tmp;
+    }
+
+    return value;
+}
+
+/**
+ *  Allocates memory for SettingParam.
+ *
+ *  \return SettingParam which must be freed using setting_param_free.
+ **/
+SettingParam *setting_param_new()
+{
+    SettingParam *param = g_slice_new(SettingParam);
+    param->id = -1;
+    param->position = -1;
+    param->value = -1;
+
+    return param;
+}
+
+/**
+ *  \param str pointer to setting param in message
+ *  \param len return location for how many bytes value is encoded on (length is added to current value)
+ *
+ *  Creates SettingParam basing on data.
+ *  This function expects str to point on:
+ *    -Parameter ID - 2 bytes
+ *    -Parameter position - 1 byte
+ *    -Parameter value - var
+ *
+ *  \return newly created SettingParam which must be freed using setting_param_free.
+ **/
+SettingParam *setting_param_new_from_data(gchar *str, gint *len)
+{
+    gint id;
+    gint position;
+    guint value;
+
+    id = ((unsigned char)str[0] << 8) | (unsigned char)str[1];
+    position = (unsigned char)str[2];
+    *len += 3;
+
+    value = unpack_value(&str[3], len);
+
+    SettingParam *param = g_slice_new(SettingParam);
+    param->id = id;
+    param->position = position;
+    param->value = value;
+
+    return param;
+}
+
+/**
+ *  \param param SettingParam to be freed
+ *
+ *  Frees all memory used by SettingParam.
+ **/
+void setting_param_free(SettingParam *param)
+{
+    g_slice_free(SettingParam, param);
+}
+
 /**
  *  \param id Parameter ID
  *  \param position Parameter position

gdigi.h

@@ -682,9 +682,18 @@ typedef enum {
     NACK = 0x7F
 } MessageID;
 
+typedef struct {
+    int id;
+    int position;
+    int value;
+} SettingParam;
+
 void send_message(gint procedure, gchar *data, gint len);
 void append_value(GString *msg, guint value);
 GString *get_message_by_id(MessageID id);
+SettingParam *setting_param_new();
+SettingParam *setting_param_new_from_data(gchar *str, gint *len);
+void setting_param_free(SettingParam *param);
 void set_option(guint id, guint position, guint value);
 void switch_preset(guint bank, guint x);
 void store_preset_name(int x, const gchar *name);

preset.c

@@ -18,6 +18,7 @@
 #include <expat.h>
 #include <string.h>
 #include "preset.h"
+#include "gdigi.h"
 
 #ifndef DOXYGEN_SHOULD_SKIP_THIS
 
@@ -53,10 +54,7 @@ static void XMLCALL start(void *data, const char *el, const char **attr) {
         if (ad->preset->params != NULL)
             g_message("Params aleady exists!");
     } else if (g_strcmp0(el, "Param") == 0) {
-        SettingParam *param = g_slice_new(SettingParam);
-        param->id = -1;
-        param->position = -1;
-        param->value = -1;
+        SettingParam *param = setting_param_new();
         ad->preset->params = g_list_prepend(ad->preset->params, param);
     } else if (g_strcmp0(el, "ID") == 0) {
         ad->id = PARSER_TYPE_PARAM_ID;
@@ -185,11 +183,7 @@ Preset *create_preset_from_data(GString *data)
 {
     gint total;
     gint n;
-    gint id;
-    gint position;
-    guint value;
     gint x;
-    gint tmp;
 
     g_return_val_if_fail(data != NULL, NULL);
 
@@ -203,27 +197,10 @@ Preset *create_preset_from_data(GString *data)
     preset->params = NULL;
 
     do {
-        id = ((unsigned char)data->str[x] << 8) | (unsigned char)data->str[x+1];
-        position = (unsigned char)data->str[x+2];
-        x+=3;
-        value = data->str[x];
-        x++;
-        if (value > 0x80) {
-            tmp = value & 0x7F;
-            value = 0;
-            gint i;
-            for (i=0; i<tmp; i++) {
-                value |= ((unsigned char)data->str[x+i] << (8*(tmp-i-1)));
-            }
-            x+=tmp;
-        }
+        SettingParam *param = setting_param_new_from_data(&data->str[x], &x);
         n++;
-        SettingParam *param = g_slice_new(SettingParam);
-        param->id = id;
-        param->position = position;
-        param->value = value;
         preset->params = g_list_prepend(preset->params, param);
-        g_message("%d ID %d Position %d Value %d", n, id, position, value);
+        g_message("%d ID %d Position %d Value %d", n, param->id, param->position, param->value);
     } while ((x < data->len) && n<total);
     g_message("TOTAL %d", total);
     preset->params = g_list_reverse(preset->params);
@@ -243,7 +220,7 @@ void preset_free(Preset *preset)
     if (preset->params != NULL) {
         GList *iter;
         for (iter = preset->params; iter; iter = iter->next) {
-            g_slice_free(SettingParam, iter->data);
+            setting_param_free((SettingParam*)iter->data);
         }
         g_list_free(preset->params);
     }

preset.h

@@ -19,12 +19,6 @@
 
 #include <glib.h>
 
-typedef struct {
-    int id;
-    int position;
-    int value;
-} SettingParam;
-
 typedef struct {
     gchar *name;
     GList *params;