Implement serverless file caching (disk or memory).

xrootd · Jun 4, 2017 · f7400a4 · f7400a4
1 parent d7a0e42
commit f7400a4
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Showing 23 changed files with 1,584 additions and 610 deletions.
diff --git a/src/XrdFileCache.cmake b/src/XrdFileCache.cmake
@@ -30,7 +30,7 @@ add_library(
 
 target_link_libraries(
   ${LIB_XRD_FILECACHE}
-  XrdPosix
+# XrdPosix
   XrdCl
   XrdUtils
   XrdServer

diff --git a/src/XrdFileCache/XrdFileCache.cc b/src/XrdFileCache/XrdFileCache.cc
@@ -40,6 +40,8 @@ using namespace XrdFileCache;
 
 Cache * Cache::m_factory = NULL;
 
+XrdScheduler *Cache::schedP = NULL;
+
 
 void *CacheDirCleanupThread(void* cache_void)
 {
@@ -61,12 +63,6 @@ void *PrefetchThread(void* ptr)
    return NULL;
 }
 
-
-namespace XrdPosixGlobals
-{
-extern XrdScheduler *schedP;
-}
-
 extern "C"
 {
 XrdOucCache2 *XrdOucGetCache2(XrdSysLogger *logger,
@@ -329,12 +325,26 @@ void Cache::ReleaseFile(File* f)
 }
 
 //______________________________________________________________________________
+
+namespace
+{
+void *callDoIt(void *pp)
+{
+     XrdJob *jP = (XrdJob *)pp;
+     jP->DoIt();
+     return (void *)0;
+}
+};
 
 void Cache::schedule_file_sync(File* f, bool ref_cnt_already_set)
 {
    DiskSyncer* ds = new DiskSyncer(f);
    if ( ! ref_cnt_already_set) inc_ref_cnt(f, true);
-   XrdPosixGlobals::schedP->Schedule(ds);
+   if (isClient) ds->DoIt();
+      else if (schedP) schedP->Schedule(ds);
+              else {pthread_t tid;
+                    XrdSysThread::Run(&tid, callDoIt, ds, 0, "DiskSyncer");
+                   }
 }
 
 //______________________________________________________________________________

diff --git a/src/XrdFileCache/XrdFileCache.hh b/src/XrdFileCache/XrdFileCache.hh
@@ -114,6 +114,10 @@ public:
    //---------------------------------------------------------------------
    virtual int isAttached();
 
+   //---------------------------------------------------------------------
+   // Virtual function of XrdOucCache2. Used to pass environmental info.
+   virtual void EnvInfo(XrdOucEnv &theEnv);
+
    //---------------------------------------------------------------------
    // Virtual function of XrdOucCache2. Used for deferred open.
    virtual int  Prepare(const char *url, int oflags, mode_t mode);
@@ -214,6 +218,8 @@ private:
    bool xtrace(XrdOucStream &);
 
    static Cache     *m_factory;         //!< this object
+   static 
+   XrdScheduler     *schedP;
 
    XrdSysError       m_log;             //!< XrdFileCache namespace logger
    XrdOucTrace      *m_trace;
@@ -232,6 +238,7 @@ private:
 
    XrdSysMutex m_RAMblock_mutex;            //!< central lock for this class
    int         m_RAMblocks_used;
+   bool        isClient;                    //!< True if running as client
 
    struct WriteQ
    {

diff --git a/src/XrdFileCache/XrdFileCacheConfiguration.cc b/src/XrdFileCache/XrdFileCacheConfiguration.cc
@@ -106,13 +106,14 @@ bool Cache::xtrace(XrdOucStream &Config)
 bool Cache::Config(XrdSysLogger *logger, const char *config_filename, const char *parameters)
 {
    m_log.logger(logger);
+   const char *theINS = getenv("XRDINSTANCE");
 
-   const char * cache_env;
-   if (! (cache_env = getenv("XRDPOSIX_CACHE")) || ! *cache_env)
-      XrdOucEnv::Export("XRDPOSIX_CACHE", "mode=s&optwr=0");
+// Indicate whether or not we are a client instance
+//
+   isClient = (strncmp("*client ", theINS, 8) != 0);
 
    XrdOucEnv myEnv;
-   XrdOucStream Config(&m_log, getenv("XRDINSTANCE"), &myEnv, "=====> ");
+   XrdOucStream Config(&m_log, theINS, &myEnv, "=====> ");
 
    if (! config_filename || ! *config_filename)
    {
@@ -418,3 +419,13 @@ bool Cache::ConfigParameters(std::string part, XrdOucStream& config, TmpConfigur
 
    return true;
 }
+
+//______________________________________________________________________________
+
+
+void Cache::EnvInfo(XrdOucEnv &theEnv)
+{
+// Extract out the pointer to the scheduler
+//
+   schedP = (XrdScheduler *)theEnv.GetPtr("XrdScheduler*");
+}
diff --git a/src/XrdFileCache/XrdFileCacheFile.cc b/src/XrdFileCache/XrdFileCacheFile.cc
@@ -33,7 +33,6 @@
 #include "XrdOuc/XrdOucEnv.hh"
 #include "XrdSfs/XrdSfsInterface.hh"
 #include "XrdFileCache.hh"
-#include "Xrd/XrdScheduler.hh"
 
 
 using namespace XrdFileCache;

diff --git a/src/XrdOuc/XrdOucCache2.hh b/src/XrdOuc/XrdOucCache2.hh
@@ -181,6 +181,7 @@ virtual    ~XrdOucCacheIO2() {}  // Always use Detach() instead of direct delete
 /*                    C l a s s   X r d O u c C a c h e 2                     */
 /******************************************************************************/
 
+class  XrdOucEnv;
 struct stat;
 
 //------------------------------------------------------------------------------
@@ -230,6 +231,18 @@ virtual
 XrdOucCache   *Create(Parms &Params, XrdOucCacheIO::aprParms *aprP=0)
                      {return this;}
 
+//------------------------------------------------------------------------------
+//! Supply environmental information to the cache for optimization. This is
+//! only called server-side but is optional and might not be called. The
+//! environmental information should only be used for optimizations. When
+//! called, it is gauranteed to occur before any active use of the cache and
+//! is essentially serialized (i.e. the main start-up thread is used).
+//!
+//! @param  theEnv - Reference to environmental information.
+//------------------------------------------------------------------------------
+virtual
+void           EnvInfo(XrdOucEnv &theEnv) {(void)theEnv;}
+
 //------------------------------------------------------------------------------
 //! Preapare the cache for a file open request. This method is called prior to
 //! actually opening a file. This method is meant to allow defering an open