[Gnash-commit] gnash ChangeLog libbase/curl_adapter.cpp

[Sandro Santilli]

CVSROOT:        /sources/gnash
Module name:    gnash
Changes by:     Sandro Santilli <strk>  07/05/07 09:33:20

Modified files:
        .              : ChangeLog 
        libbase        : curl_adapter.cpp 

Log message:
                * libbase/curl_adapter.cpp (fill_cache): avoid aggressive 
polling by
                  taking naps between iterations. "Smart" sleep times are taken
                  in consideration so we can tweak them.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/gnash/ChangeLog?cvsroot=gnash&r1=1.3114&r2=1.3115
http://cvs.savannah.gnu.org/viewcvs/gnash/libbase/curl_adapter.cpp?cvsroot=gnash&r1=1.30&r2=1.31

Patches:
Index: ChangeLog
===================================================================
RCS file: /sources/gnash/gnash/ChangeLog,v
retrieving revision 1.3114
retrieving revision 1.3115
diff -u -b -r1.3114 -r1.3115
--- ChangeLog   7 May 2007 07:25:06 -0000       1.3114
+++ ChangeLog   7 May 2007 09:33:20 -0000       1.3115
@@ -1,5 +1,11 @@
 2007-05-07 Sandro Santilli <address@hidden>
 
+       * libbase/curl_adapter.cpp (fill_cache): avoid aggressive polling by
+         taking naps between iterations. "Smart" sleep times are taken
+         in consideration so we can tweak them.
+
+2007-05-07 Sandro Santilli <address@hidden>
+
        * libbase/LoadThread.{cpp,h}: Make thread usage a compile-time
          configuration. Temporarely defaults to NOT using thread till
          we fix bug #19811 and general CPU hogs during loading.

Index: libbase/curl_adapter.cpp
===================================================================
RCS file: /sources/gnash/gnash/libbase/curl_adapter.cpp,v
retrieving revision 1.30
retrieving revision 1.31
diff -u -b -r1.30 -r1.31
--- libbase/curl_adapter.cpp    2 May 2007 16:24:12 -0000       1.30
+++ libbase/curl_adapter.cpp    7 May 2007 09:33:20 -0000       1.31
@@ -17,7 +17,7 @@
 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 //
 
-/* $Id: curl_adapter.cpp,v 1.30 2007/05/02 16:24:12 rsavoye Exp $ */
+/* $Id: curl_adapter.cpp,v 1.31 2007/05/07 09:33:20 strk Exp $ */
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
@@ -32,6 +32,7 @@
 #include <map>
 #include <iostream>
 #include <string>
+#include <unistd.h> // for usleep
 
 using namespace std;
 
@@ -124,6 +125,14 @@
        bool seek_to_end();
 
        /// Returns the size of the stream
+       //
+       /// If size of the stream is unknown, 0 is returned.
+       /// In that case you might try calling this function
+       /// again after filling the cache a bit...
+       ///
+       /// Another approach might be filling the cache ourselves
+       /// aiming at obtaining a useful value.
+       ///
        long get_stream_size();
 
 private:
@@ -163,9 +172,15 @@
        // Current size of cached data
        long unsigned _cached;
 
+       /// Total stream size.
+       //
+       /// This will be 0 until known
+       ///
+       long unsigned _size;
+
        // Attempt at filling the cache up to the given size.
        // Will call libcurl routines to fetch data.
-       void fill_cache(off_t size);
+       void fill_cache(long unsigned size);
 
        // Append sz bytes to the cache
        size_t cache(void *from, size_t sz);
@@ -245,13 +260,31 @@
 
 /*private*/
 void
-CurlStreamFile::fill_cache(off_t size)
+CurlStreamFile::fill_cache(long unsigned size)
 {
 #ifdef GNASH_CURL_VERBOSE
        fprintf(stderr, "fill_cache(%d) called\n", size);
 #endif
 
+// Disable this when you're convinced the sleeping mechanism is satisfactory
+#define VERBOSE_POLLING_LOOP 1
+
+#if VERBOSE_POLLING_LOOP
+       long unsigned fetchRequested = size-_cached;
+#endif
+
+       // These are the minimum and maximum times in microseconds
+       // to nap between curl_multi_perform calls if the amount
+       // of data requested haven't arrived yet.
+       // 
+       const long unsigned minSleep =  500000; // half second
+       const long unsigned maxSleep = 1000000; // one second
+
        CURLMcode mcode;
+#if VERBOSE_POLLING_LOOP
+       long unsigned lastCached = _cached;
+#endif
+       long unsigned sleepTime = minSleep;
        while (_cached < size && _running)
        {
                do
@@ -264,6 +297,26 @@
                        throw gnash::GnashException(curl_multi_strerror(mcode));
                }
 
+               // done...
+               if ( _cached >= size || ! _running ) break;
+
+               // In order to avoid overusing the CPU we take a nap if we 
didn't
+               // reach the requested position.
+
+#if VERBOSE_POLLING_LOOP
+               long unsigned fetched = _cached - lastCached;
+
+               fprintf(stderr, "CurlStreamFile %p: Fetched: %lu (%lu/%lu 
total) - requested %lu (%lu total) - sleeping %lu milliseconds\n",
+                               this, fetched, _cached, get_stream_size(), 
fetchRequested, size, sleepTime/1000);
+               lastCached = _cached;
+#endif
+
+               usleep(sleepTime);
+
+               // If we'll need to sleep again we'll sleep more next time...
+               // Up to a max (maxSleep)
+               sleepTime = std::min(sleepTime*2, maxSleep);
+
        }
 
        // TODO: check for 404 only once !
@@ -297,6 +350,7 @@
        _error = 0;
 
        _cached = 0;
+       _size = 0;
 
        _handle = curl_easy_init();
        _mhandle = curl_multi_init();
@@ -528,16 +582,18 @@
 long
 CurlStreamFile::get_stream_size()
 {
+       if ( ! _size )
+       {
        double size;
-       curl_easy_getinfo(_handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &size);
-
-       int ret = static_cast<long>(size);
+               CURLcode ret = curl_easy_getinfo(_handle, 
CURLINFO_CONTENT_LENGTH_DOWNLOAD, &size);
+               if ( ret == CURLE_OK ) _size = int(size);
+       }
 
 #ifdef GNASH_CURL_VERBOSE
-       fprintf(stderr, "get_stream_size() returning %ld\n", ret);
+       fprintf(stderr, "get_stream_size() returning %lu\n", _size);
 #endif
 
-       return ret;
+       return _size;
 
 }