BUG: #1526: add a per-instance default ram value in StreamingManager

Modules/Core/Streaming/include/otbStreamingManager.h

@@ -88,6 +88,9 @@ public:
    * GetNumberOfSplits() returns. */
   virtual RegionType GetSplit(unsigned int i);
 
+  itkSetMacro(DefaultRAM, MemoryPrintType);
+  itkGetMacro(DefaultRAM, MemoryPrintType);
+
 protected:
   StreamingManager();
   ~StreamingManager() ITK_OVERRIDE;
@@ -111,11 +114,13 @@ private:
   StreamingManager(const StreamingManager &); //purposely not implemented
   void operator =(const StreamingManager&);   //purposely not implemented
 
-  /* Compute the available RAM from configuration settings if the input parameter is 0,
-   * otherwise, simply returns the input parameter */
+  /** Compute the available RAM in Bytes from an input value in MByte.
+   *  If the input value is 0, it uses the m_DefaultRAM value.
+   *  If m_DefaultRAM is also 0, it uses the configuration settings */
   MemoryPrintType GetActualAvailableRAMInBytes(MemoryPrintType availableRAMInMB);
 
-
+  /** Default available RAM in MB */
+  MemoryPrintType m_DefaultRAM;
 };
 
 } // End namespace otb

Modules/Core/Streaming/include/otbStreamingManager.txx

@@ -31,6 +31,7 @@ namespace otb
 template <class TImage>
 StreamingManager<TImage>::StreamingManager()
   : m_ComputedNumberOfSplits(0)
+  , m_DefaultRAM(0)
 {
 }
 
@@ -47,9 +48,16 @@ StreamingManager<TImage>::GetActualAvailableRAMInBytes(MemoryPrintType available
 
   if (availableRAMInBytes == 0)
     {
-    otbMsgDevMacro(<< "Retrieving available RAM size from configuration");
-    // Retrieve it from the configuration
-    availableRAMInBytes = 1024*1024*ConfigurationManager::GetMaxRAMHint();
+    if (m_DefaultRAM != 0)
+      {
+      availableRAMInBytes = 1024*1024*m_DefaultRAM;
+      }
+    else
+      {
+      otbMsgDevMacro(<< "Retrieving available RAM size from configuration");
+      // Retrieve it from the configuration
+      availableRAMInBytes = 1024*1024*ConfigurationManager::GetMaxRAMHint();
+      }
     }
 
   otbMsgDevMacro("RAM used to estimate memory footprint : " << availableRAMInBytes / 1024 / 1024  << " MB")