Add truncate to FileWriter routine.

coding/coding_tests/file_container_test.cpp

@@ -3,6 +3,7 @@
 #include "../file_container.hpp"
 #include "../varint.hpp"
 
+#include "../../base/logging.hpp"
 #include "../../base/string_utils.hpp"
 
 
@@ -146,6 +147,7 @@ namespace
                       char const * key[], char const * value[], size_t count)
   {
     FilesContainerR reader(fName);
+    LOG(LINFO, ("Size=", reader.GetSize()));
 
     for (size_t i = 0; i < count; ++i)
     {

coding/file_container.cpp

@@ -179,6 +179,7 @@ FileWriter FilesContainerW::GetWriter(Tag const & tag)
 
     FileWriter writer(m_name, FileWriter::OP_WRITE_EXISTING);
     writer.Seek(curr);
+    writer.Truncate(curr);
     return writer;
   }
   else
@@ -224,17 +225,15 @@ void FilesContainerW::Finish()
 {
   ASSERT(!m_bFinished, ());
 
-  {
-    uint64_t const curr = SaveCurrentSize();
-    FileWriter writer(m_name, FileWriter::OP_WRITE_EXISTING);
-    writer.Seek(0);
-    WriteToSink(writer, curr);
-  }
+  uint64_t const curr = SaveCurrentSize();
+
+  FileWriter writer(m_name, FileWriter::OP_WRITE_EXISTING);
+  writer.Seek(0);
+  WriteToSink(writer, curr);
+  writer.Seek(curr);
 
   sort(m_info.begin(), m_info.end(), LessInfo());
 
-  FileWriter writer(m_name, FileWriter::OP_APPEND);
-
   uint32_t const count = m_info.size();
   WriteVarUint(writer, count);
 

coding/file_container.hpp

@@ -98,6 +98,8 @@ public:
       f(m_info[i].m_tag);
   }
 
+  inline uint64_t GetSize() const { return m_source.Size(); }
+
 private:
   ReaderT m_source;
 };

coding/file_writer.cpp

@@ -51,6 +51,11 @@ void FileWriter::Flush()
   m_pFileData->Flush();
 }
 
+void FileWriter::Truncate(uint64_t sz)
+{
+  m_pFileData->Truncate(sz);
+}
+
 void FileWriter::DeleteFileX(string const & fName)
 {
     my::DeleteFileX(fName);

coding/file_writer.hpp

@@ -33,8 +33,10 @@ public:
   void Seek(int64_t pos);
   int64_t Pos() const;
   void Write(void const * p, size_t size);
+
   uint64_t Size() const;
   void Flush();
+  void Truncate(uint64_t sz);
 
   static void DeleteFileX(string const & fName);
 

coding/internal/file_data.cpp

@@ -153,6 +153,15 @@ void FileData::Flush()
 #endif
 }
 
+void FileData::Truncate(uint64_t sz)
+{
+#ifdef OMIM_OS_WINDOWS
+  _chsize(fileno(m_File), sz);
+#else
+  ftruncate(fileno(m_File), sz);
+#endif
+}
+
 bool GetFileSize(string const & fName, uint64_t & sz)
 {
   try

coding/internal/file_data.hpp

@@ -27,7 +27,9 @@ public:
 
   void Read(uint64_t pos, void * p, size_t size);
   void Write(void const * p, size_t size);
+
   void Flush();
+  void Truncate(uint64_t sz);
 
   string GetName() const { return m_FileName; }