[Spice-devel] [PATCH spice-streaming-agent v3 2/2] Add support log logging statistics from plugins

[Frediano Ziglio]

Allows the plugins to add information to the log.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 include/spice-streaming-agent/plugin.hpp |  7 ++++++-
 src/concrete-agent.cpp                   | 21 +++++++++++++++++----
 src/concrete-agent.hpp                   |  8 +++++++-
 src/frame-log.cpp                        | 11 ++++++++---
 src/frame-log.hpp                        |  2 ++
 src/spice-streaming-agent.cpp            |  6 +++---
 6 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/include/spice-streaming-agent/plugin.hpp b/include/spice-streaming-agent/plugin.hpp
index 3b265d9..88cb7f2 100644
--- a/include/spice-streaming-agent/plugin.hpp
+++ b/include/spice-streaming-agent/plugin.hpp
@@ -28,7 +28,7 @@ class FrameCapture;
  * where MM is major and mm is the minor, can be easily expanded
  * using more bits in the future
  */
-enum Constants : unsigned { PluginVersion = 0x100u };
+enum Constants : unsigned { PluginVersion = 0x101u };
 
 enum Ranks : unsigned {
     /// this plugin should not be used
@@ -116,6 +116,11 @@ public:
      * \todo passing options to entry point instead?
      */
     virtual const ConfigureOption* Options() const = 0;
+    /*!
+     * Write something in the log.
+     */
+    __attribute__ ((format (printf, 2, 3)))
+    virtual void LogStat(const char* format, ...) = 0;
 };
 
 typedef bool PluginInitFunc(spice::streaming_agent::Agent* agent);
diff --git a/src/concrete-agent.cpp b/src/concrete-agent.cpp
index fb1412b..336bd09 100644
--- a/src/concrete-agent.cpp
+++ b/src/concrete-agent.cpp
@@ -5,13 +5,15 @@
  */
 
 #include <config.h>
+#include "concrete-agent.hpp"
+#include "frame-log.hpp"
+
 #include <algorithm>
 #include <syslog.h>
 #include <glob.h>
 #include <dlfcn.h>
 #include <string>
-
-#include "concrete-agent.hpp"
+#include <cstdarg>
 
 using namespace spice::streaming_agent;
 
@@ -25,8 +27,9 @@ static inline unsigned MinorVersion(unsigned version)
     return version & 0xffu;
 }
 
-ConcreteAgent::ConcreteAgent(const std::vector<ConcreteConfigureOption> &options):
-    options(options)
+ConcreteAgent::ConcreteAgent(const std::vector<ConcreteConfigureOption> &options, FrameLog *logger):
+    options(options),
+    logger(logger)
 {
     this->options.push_back(ConcreteConfigureOption(nullptr, nullptr));
 }
@@ -140,3 +143,13 @@ FrameCapture *ConcreteAgent::GetBestFrameCapture(const std::set<SpiceVideoCodecT
     }
     return nullptr;
 }
+
+void ConcreteAgent::LogStat(const char* format, ...)
+{
+    if (logger) {
+        va_list ap;
+        va_start(ap, format);
+        logger->log_statv(format, ap);
+        va_end(ap);
+    }
+}
diff --git a/src/concrete-agent.hpp b/src/concrete-agent.hpp
index 2c2ebc8..6d1be35 100644
--- a/src/concrete-agent.hpp
+++ b/src/concrete-agent.hpp
@@ -14,6 +14,8 @@
 namespace spice {
 namespace streaming_agent {
 
+class FrameLog;
+
 struct ConcreteConfigureOption: ConfigureOption
 {
     ConcreteConfigureOption(const char *name, const char *value)
@@ -26,16 +28,20 @@ struct ConcreteConfigureOption: ConfigureOption
 class ConcreteAgent final : public Agent
 {
 public:
-    ConcreteAgent(const std::vector<ConcreteConfigureOption> &options);
+    ConcreteAgent(const std::vector<ConcreteConfigureOption> &options,
+                  FrameLog *logger=nullptr);
     void Register(const std::shared_ptr<Plugin>& plugin) override;
     const ConfigureOption* Options() const override;
     void LoadPlugins(const std::string &directory);
     FrameCapture *GetBestFrameCapture(const std::set<SpiceVideoCodecType>& codecs);
+    __attribute__ ((format (printf, 2, 3)))
+    void LogStat(const char* format, ...) override;
 private:
     bool PluginVersionIsCompatible(unsigned pluginVersion) const;
     void LoadPlugin(const std::string &plugin_filename);
     std::vector<std::shared_ptr<Plugin>> plugins;
     std::vector<ConcreteConfigureOption> options;
+    FrameLog *const logger = nullptr;
 };
 
 }} // namespace spice::streaming_agent
diff --git a/src/frame-log.cpp b/src/frame-log.cpp
index 62fffc3..f416cde 100644
--- a/src/frame-log.cpp
+++ b/src/frame-log.cpp
@@ -41,13 +41,18 @@ FrameLog::~FrameLog()
 }
 
 void FrameLog::log_stat(const char* format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    log_statv(format, ap);
+    va_end(ap);
+}
+
+void FrameLog::log_statv(const char* format, va_list ap)
 {
     if (log_file && !log_binary) {
         fprintf(log_file, "%" PRIu64 ": ", get_time());
-        va_list ap;
-        va_start(ap, format);
         vfprintf(log_file, format, ap);
-        va_end(ap);
         fputc('\n', log_file);
     }
 }
diff --git a/src/frame-log.hpp b/src/frame-log.hpp
index 8503345..a104723 100644
--- a/src/frame-log.hpp
+++ b/src/frame-log.hpp
@@ -24,6 +24,8 @@ public:
 
     __attribute__ ((format (printf, 2, 3)))
     void log_stat(const char* format, ...);
+    __attribute__ ((format (printf, 2, 0)))
+    void log_statv(const char* format, va_list ap);
     void log_frame(const void* buffer, size_t buffer_size);
 
     static uint64_t get_time();
diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 039d628..49f5dc4 100644
--- a/src/spice-streaming-agent.cpp
+++ b/src/spice-streaming-agent.cpp
@@ -401,15 +401,15 @@ int main(int argc, char* argv[])
     register_interrupts();
 
     try {
-        ConcreteAgent agent(options);
+        FrameLog frame_log(log_filename, log_binary, log_frames);
+
+        ConcreteAgent agent(options, &frame_log);
 
         // register built-in plugins
         MjpegPlugin::Register(&agent);
 
         agent.LoadPlugins(pluginsdir);
 
-        FrameLog frame_log(log_filename, log_binary, log_frames);
-
         for (const std::string& arg: old_args) {
             frame_log.log_stat("Args: %s", arg.c_str());
         }
-- 
2.20.1