real time indexer: monitor the configuration for changes and reexecute when needed

src/utils/conftree.cpp

@@ -23,6 +23,7 @@
 #include <unistd.h> // for access(2)
 #include <ctype.h>
 #include <fnmatch.h>
+#include <sys/stat.h>
 
 #include <fstream>
 #include <sstream>
@@ -145,13 +146,13 @@ void ConfSimple::parseinput(istream &input)
 
 
 ConfSimple::ConfSimple(int readonly, bool tildexp)
-    : dotildexpand(tildexp), m_holdWrites(false)
+    : dotildexpand(tildexp), m_fmtime(0), m_holdWrites(false)
 {
     status = readonly ? STATUS_RO : STATUS_RW;
 }
 
 ConfSimple::ConfSimple(const string& d, int readonly, bool tildexp)
-    : dotildexpand(tildexp), m_holdWrites(false)
+    : dotildexpand(tildexp), m_fmtime(0), m_holdWrites(false)
 {
     status = readonly ? STATUS_RO : STATUS_RW;
 
@@ -160,7 +161,7 @@ ConfSimple::ConfSimple(const string& d, int readonly, bool tildexp)
 }
 
 ConfSimple::ConfSimple(const char *fname, int readonly, bool tildexp)
-    : dotildexpand(tildexp), m_filename(fname), m_holdWrites(false)
+    : dotildexpand(tildexp), m_filename(fname), m_fmtime(0), m_holdWrites(false)
 {
     status = readonly ? STATUS_RO : STATUS_RW;
 
@@ -193,6 +194,7 @@ ConfSimple::ConfSimple(const char *fname, int readonly, bool tildexp)
     }	    
 
     parseinput(input);
+    i_changed(true);
 }
 
 ConfSimple::StatusCode ConfSimple::getStatus() const
@@ -204,6 +206,26 @@ ConfSimple::StatusCode ConfSimple::getStatus() const
     }
 }
 
+bool ConfSimple::sourceChanged()
+{
+    return i_changed(false);
+}
+
+bool ConfSimple::i_changed(bool upd)
+{
+    if (!m_filename.empty()) {
+	struct stat st;
+	if (stat(m_filename.c_str(), &st) == 0) {
+	    if (m_fmtime != st.st_mtime) {
+		if (upd)
+		    m_fmtime = st.st_mtime;
+		return true;
+	    }
+	}
+    }
+    return false;
+}
+
 int ConfSimple::get(const string &nm, string &value, const string &sk) const
 {
     if (!ok())

src/utils/conftree.h

@@ -107,6 +107,7 @@ public:
     virtual list<string> getSubKeys() = 0;
     virtual list<string> getSubKeys(bool) = 0;
     virtual bool holdWrites(bool) = 0;
+    virtual bool sourceChanged() = 0;
 };
 
 /** 
@@ -140,6 +141,9 @@ public:
 
     virtual ~ConfSimple() {};
 
+    /** Origin file changed. Only makes sense if we read the data from a file */
+    virtual bool sourceChanged();
+
     /** 
      * Decide if we actually rewrite the backing-store after modifying the
      * tree.
@@ -252,6 +256,7 @@ protected:
 private:
     // Set if we're working with a file
     string                            m_filename; 
+    time_t                            m_fmtime;
     // Configuration data submaps (one per subkey, the main data has a
     // null subkey)
     map<string, map<string, string> > m_submaps;
@@ -267,6 +272,7 @@ private:
     // Internal version of set: no RW checking
     virtual int i_set(const string &nm, const string &val, 
 		      const string &sk, bool init = false);
+    bool i_changed(bool upd);
 };
 
 /**
@@ -366,6 +372,16 @@ public:
 	return *this;
     }
 
+    virtual bool sourceChanged()
+    {
+	typename list<T*>::const_iterator it;
+	for (it = m_confs.begin();it != m_confs.end();it++) {
+	    if ((*it)->sourceChanged())
+		return true;
+	}
+	return false;
+    }
+
     virtual int get(const string &name, string &value, const string &sk) const
     {
 	typename list<T*>::const_iterator it;