Merge pull request #13769 from ghalliday/issue24074

HPCC-24074 Avoid calling fileio->size() from compression code if overwriting

Reviewed-By: Mark Kelly <mark.kelly@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>

dali/ft/fttransform.cpp

@@ -846,7 +846,7 @@ processedProgress:
                     decrypt(key,encryptKey);
                     compressor.setown(createAESCompressor256(key.length(),key.str()));
                 }
-                outio.setown(createCompressedFileWriter(outio, 0, true, compressor, COMPRESS_METHOD_LZW));
+                outio.setown(createCompressedFileWriter(outio, false, 0, true, compressor, COMPRESS_METHOD_LZW));
             }
 
             LOG(MCdebugProgress, unknownJob, "Start pulling to file: %s", localFilename.str());
@@ -972,7 +972,7 @@ bool TransferServer::push()
                     decrypt(key,encryptKey);
                     compressor.setown(createAESCompressor256(key.length(),key.str()));
                 }
-                outio.setown(createCompressedFileWriter(outio, 0, true, compressor, COMPRESS_METHOD_LZW));
+                outio.setown(createCompressedFileWriter(outio, false, 0, true, compressor, COMPRESS_METHOD_LZW));
             }
             out.setown(createIOStream(outio));
             if (!compressOutput)

system/jlib/jlzw.cpp

@@ -2428,10 +2428,10 @@ ICompressedFileIO *createCompressedFileReader(IFile *file,IExpander *expander, b
 
 
 
-ICompressedFileIO *createCompressedFileWriter(IFileIO *fileio,size32_t recordsize,bool _setcrc,ICompressor *compressor, unsigned _compMethod)
+ICompressedFileIO *createCompressedFileWriter(IFileIO *fileio, bool append, size32_t recordsize,bool _setcrc,ICompressor *compressor, unsigned _compMethod)
 {
     CompressedFileTrailer trailer;
-    offset_t fsize = fileio->size();
+    offset_t fsize = append ? fileio->size() : 0;
     if (fsize)
     {
         for (;;)
@@ -2493,7 +2493,7 @@ ICompressedFileIO *createCompressedFileWriter(IFile *file,size32_t recordsize,bo
             append = false;
         Owned<IFileIO> fileio = file->open(append?IFOreadwrite:IFOcreate, extraFlags);
         if (fileio) 
-            return createCompressedFileWriter(fileio,recordsize,_setcrc,compressor,_compMethod);
+            return createCompressedFileWriter(fileio,append,recordsize,_setcrc,compressor,_compMethod);
     }
     return NULL;
 }

system/jlib/jlzw.hpp

@@ -115,7 +115,7 @@ extern jlib_decl bool isCompressedFile(IFile *file);
 extern jlib_decl ICompressedFileIO *createCompressedFileReader(IFile *file,IExpander *expander=NULL, bool memorymapped=false, IFEflags extraFlags=IFEnone);
 extern jlib_decl ICompressedFileIO *createCompressedFileReader(IFileIO *fileio,IExpander *expander=NULL);
 extern jlib_decl ICompressedFileIO *createCompressedFileWriter(IFile *file,size32_t recordsize,bool append=false,bool setcrc=true,ICompressor *compressor=NULL, unsigned compMethod=COMPRESS_METHOD_LZ4, IFEflags extraFlags=IFEnone);
-extern jlib_decl ICompressedFileIO *createCompressedFileWriter(IFileIO *fileio,size32_t recordsize,bool setcrc=true,ICompressor *compressor=NULL, unsigned compMethod=COMPRESS_METHOD_LZ4);
+extern jlib_decl ICompressedFileIO *createCompressedFileWriter(IFileIO *fileio, bool append, size32_t recordsize,bool setcrc=true,ICompressor *compressor=NULL, unsigned compMethod=COMPRESS_METHOD_LZ4);
 
 #define COMPRESSEDFILECRC (~0U)