diff plugincandidates.h @ 2:2288c1d05c28

Simple Qt-based class to invoke the helper

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugincandidates.h	Tue Apr 12 17:38:57 2016 +0100
@@ -0,0 +1,67 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+#ifndef PLUGIN_CANDIDATES_H
+#define PLUGIN_CANDIDATES_H
+
+#include <string>
+#include <vector>
+#include <map>
+
+/**
+ * Class to identify and list candidate shared-library files possibly
+ * containing plugins. Uses a separate process (the "helper", whose
+ * executable name must be provided at construction) to test-load each
+ * library in order to winnow out any that fail to load or crash on
+ * load.
+ *
+ * Requires C++11 and the Qt5 QtCore library.
+ */
+class PluginCandidates
+{
+    typedef std::vector<std::string> stringlist;
+    
+public:
+    /** Construct a PluginCandidates scanner that uses the given
+     *  executable as its load check helper.
+     */
+    PluginCandidates(std::string helperExecutableName);
+
+    /** Scan the libraries found in the given plugin path (i.e. list
+     *  of plugin directories), checking that the given descriptor
+     *  function can be looked up in each. Store the results
+     *  internally, associated with the given (arbitrary) tag, for
+     *  later querying using getCandidateLibrariesFor() and
+     *  getFailedLibrariesFor().
+     *
+     *  Not thread-safe.
+     */
+    void scan(std::string tag,
+	      stringlist pluginPath,
+	      std::string descriptorFunctionName);
+
+    /** Return list of plugin library paths that were checked
+     *  successfully during the scan for the given tag.
+     */
+    stringlist getCandidateLibrariesFor(std::string tag);
+
+    struct FailureRec {
+	std::string library;
+	std::string message;
+    };
+
+    /** Return list of failure reports arising from the prior scan for
+     *  the given tag. 
+     */
+    std::vector<FailureRec> getFailedLibrariesFor(std::string tag);
+
+private:
+    std::string m_helper;
+    std::map<std::string, stringlist> m_candidates;
+    std::map<std::string, std::vector<FailureRec> > m_failures;
+
+    stringlist getLibrariesInPath(stringlist path);
+    stringlist runHelper(stringlist libraries, std::string descriptor);
+    void recordResult(std::string tag, stringlist results);
+};
+
+#endif