flush internal buffers before auto-saving control file

Otherwise, some pieces may be marked as finished in the control file though they have not yet been written to the storage file. This should prevent data loss and corruption when resuming downloads after an app crash. Signed-off-by: Ali MJ Al-Nasrawy <[email protected]>
yew0901c · Jun 17, 2020 · 870e2a6 · 870e2a6
1 parent 9d0a48a
commit 870e2a6
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Showing 6 changed files with 14 additions and 8 deletions.
diff --git a/src/DefaultPieceStorage.cc b/src/DefaultPieceStorage.cc
@@ -685,7 +685,7 @@ std::shared_ptr<DiskAdaptor> DefaultPieceStorage::getDiskAdaptor()
 
 WrDiskCache* DefaultPieceStorage::getWrDiskCache() { return wrDiskCache_; }
 
-void DefaultPieceStorage::flushWrDiskCacheEntry()
+void DefaultPieceStorage::flushWrDiskCacheEntry(bool releaseEntries)
 {
   if (!wrDiskCache_) {
     return;
@@ -697,7 +697,9 @@ void DefaultPieceStorage::flushWrDiskCacheEntry()
     auto ce = piece->getWrDiskCacheEntry();
     if (ce) {
       piece->flushWrCache(wrDiskCache_);
-      piece->releaseWrCache(wrDiskCache_);
+      if (releaseEntries) {
+        piece->releaseWrCache(wrDiskCache_);
+      }
     }
   }
 }

diff --git a/src/DefaultPieceStorage.h b/src/DefaultPieceStorage.h
@@ -234,7 +234,7 @@ class DefaultPieceStorage : public PieceStorage {
 
   virtual WrDiskCache* getWrDiskCache() CXX11_OVERRIDE;
 
-  virtual void flushWrDiskCacheEntry() CXX11_OVERRIDE;
+  virtual void flushWrDiskCacheEntry(bool releaseEntries) CXX11_OVERRIDE;
 
   virtual int32_t getPieceLength(size_t index) CXX11_OVERRIDE;
 

diff --git a/src/PieceStorage.h b/src/PieceStorage.h
@@ -226,8 +226,9 @@ class PieceStorage {
 
   virtual WrDiskCache* getWrDiskCache() = 0;
 
-  // Flushes write disk cache for in-flight piece and evicts them.
-  virtual void flushWrDiskCacheEntry() = 0;
+  // Flushes write disk cache for in-flight piece
+  // and optionally releases the associated cache entries.
+  virtual void flushWrDiskCacheEntry(bool releaseEntries) = 0;
 
   virtual int32_t getPieceLength(size_t index) = 0;
 

diff --git a/src/RequestGroup.cc b/src/RequestGroup.cc
@@ -210,7 +210,7 @@ std::pair<error_code::Value, std::string> RequestGroup::downloadResult() const
 void RequestGroup::closeFile()
 {
   if (pieceStorage_) {
-    pieceStorage_->flushWrDiskCacheEntry();
+    pieceStorage_->flushWrDiskCacheEntry(true);
     pieceStorage_->getDiskAdaptor()->closeFile();
   }
 }
@@ -1290,6 +1290,9 @@ bool RequestGroup::doesUploadSpeedExceed()
 void RequestGroup::saveControlFile() const
 {
   if (saveControlFile_) {
+    if (pieceStorage_) {
+      pieceStorage_->flushWrDiskCacheEntry(false);
+    }
     progressInfoFile_->save();
   }
 }

diff --git a/src/UnknownLengthPieceStorage.h b/src/UnknownLengthPieceStorage.h
@@ -216,7 +216,7 @@ class UnknownLengthPieceStorage : public PieceStorage {
 
   virtual WrDiskCache* getWrDiskCache() CXX11_OVERRIDE { return nullptr; }
 
-  virtual void flushWrDiskCacheEntry() CXX11_OVERRIDE {}
+  virtual void flushWrDiskCacheEntry(bool releaseEntries) CXX11_OVERRIDE {}
 
   virtual int32_t getPieceLength(size_t index) CXX11_OVERRIDE;
 

diff --git a/test/MockPieceStorage.h b/test/MockPieceStorage.h
@@ -228,7 +228,7 @@ class MockPieceStorage : public PieceStorage {
 
   virtual WrDiskCache* getWrDiskCache() CXX11_OVERRIDE { return 0; }
 
-  virtual void flushWrDiskCacheEntry() CXX11_OVERRIDE {}
+  virtual void flushWrDiskCacheEntry(bool releaseEntries) CXX11_OVERRIDE {}
 
   void setDiskAdaptor(const std::shared_ptr<DiskAdaptor>& adaptor)
   {