Use mapfile directly instead of buffer

src/stardict_lib.cpp

@@ -831,19 +831,14 @@ bool WordListIndex::lookup(const char *str, glong &idx)
 
 bool SynFile::load(const std::string &url, gulong wc)
 {
-
     struct stat stat_buf;
     if (!stat(url.c_str(), &stat_buf)) {
 
-        MapFile syn;
-        if (!syn.open(url.c_str(), stat_buf.st_size))
+        if (!synfile.open(url.c_str(), stat_buf.st_size))
             return false;
 
-        syndatabuf = (gchar *)g_malloc(stat_buf.st_size);
-        memcpy(syndatabuf, syn.begin(),  stat_buf.st_size);
-
         synlist.resize(wc + 1);
-        gchar *p1 = syndatabuf;
+        gchar *p1 = synfile.begin();
 
         for (unsigned long i = 0; i < wc; i++) {
             // each entry in a syn-file is:

src/stardict_lib.hpp

@@ -102,17 +102,14 @@ public:
 class SynFile
 {
 public:
-    SynFile()
-        : syndatabuf(nullptr)
-    {
-    }
-    ~SynFile() { g_free(syndatabuf); }
+    SynFile() {}
+    ~SynFile() {}
     bool load(const std::string &url, gulong wc);
     bool lookup(const char *str, glong &idx);
     const gchar *get_key(glong idx) { return synlist[idx]; }
 
 private:
-    gchar *syndatabuf;
+    MapFile synfile;
     std::vector<gchar *> synlist;
 };