Why do I only get the first few lines of file when using GZipStream to decompress in dotnet core

I'm trying to read a series of gzip files using the code below.

What I end up with is a file that is only a fraction of the total file. Interestingly enough the text file output is almost perfectly truncated at a line break.

public static string UnzipFile(string filename)

{

    FileInfo fi = new FileInfo(filename);

    Console.WriteLine($" - - - - - UnzipFile {filename} {fi.Length} - - - - - ");

    string newFileName = filename.Substring(0, filename.Length - 4);



    try

    {

       byte buffer = new byte[4096]; // read in chunks of 4KB

       using (FileStream fs2 = new FileStream(newFileName, FileMode.CreateNew))

       {

          using (FileStream fs = new FileStream(filename, FileMode.Open))

          {

             using (GZipStream zipStream = new GZipStream(fs, CompressionMode.Decompress))

             {

                zipStream.BufferSize = 1024;

                int bytesRead;

                while((bytesRead = zipStream.Read(buffer, 0, buffer.Length)) > 0)

                {

                   Console.WriteLine($" {bytesRead}  ");

                   fs2.Write(buffer, 0, bytesRead);

                   fs2.Flush(true);

                }          

             }           

         }

      }

      FileInfo fi2 = new FileInfo(newFileName);

      Console.WriteLine($" - - - - {newFileName} {fi2.Length}");

      }

      catch (Exception e)

      {

         Console.WriteLine($" - - - - - EXCEPTION {e.Message} {e.StackTrace}");

      }

      return newFileName;

 }

Here is partial output from running the code:

UnzipFile : 177686_2018-10-18_0#289.json.gz 34975

4096

4096

 855

            177686_2018-10-18_0#289.json 9047

So it looks like a file of size 34975 bytes when compressed ends up decompressing only 9047 bytes. If I use gunzip on a mac to expand the file I get a file 223344 bytes in size.

Where have I gone wrong?

edit: Additional data

In case it helps, I get this when using GZip.Decompress

Bad CRC32 in GZIP trailer. (actual(7C64AEAA)!=expected(F641B726)) at Ionic.Zlib.ZlibBaseStream.finish()

Additional data when examining the position of the FileStream

fs pos: 2093 fs len: 33930

edited Nov 15 '18 at 14:32

asked Nov 15 '18 at 1:47

Zain Mecklai

By the way, streams have a CopyTo method :)
– John
Nov 15 '18 at 2:03

Are you able to attach an example input to your code so people can test it?
– mjwills
Nov 15 '18 at 2:23

@mjwills I have proprietary data in the files so that's a blocker for me. I'll see if I can scrub some of it. If it helps, I get it from Amplitude's API amplitude.zendesk.com/hc/en-us/articles/…
– Zain Mecklai
Nov 15 '18 at 2:42

1

@John Thanks! I'll incorporate that! Appreciate the tip.
– Zain Mecklai
Nov 15 '18 at 2:42

add a comment |

I'm trying to read a series of gzip files using the code below.

What I end up with is a file that is only a fraction of the total file. Interestingly enough the text file output is almost perfectly truncated at a line break.

public static string UnzipFile(string filename)

{

    FileInfo fi = new FileInfo(filename);

    Console.WriteLine($" - - - - - UnzipFile {filename} {fi.Length} - - - - - ");

    string newFileName = filename.Substring(0, filename.Length - 4);



    try

    {

       byte buffer = new byte[4096]; // read in chunks of 4KB

       using (FileStream fs2 = new FileStream(newFileName, FileMode.CreateNew))

       {

          using (FileStream fs = new FileStream(filename, FileMode.Open))

          {

             using (GZipStream zipStream = new GZipStream(fs, CompressionMode.Decompress))

             {

                zipStream.BufferSize = 1024;

                int bytesRead;

                while((bytesRead = zipStream.Read(buffer, 0, buffer.Length)) > 0)

                {

                   Console.WriteLine($" {bytesRead}  ");

                   fs2.Write(buffer, 0, bytesRead);

                   fs2.Flush(true);

                }          

             }           

         }

      }

      FileInfo fi2 = new FileInfo(newFileName);

      Console.WriteLine($" - - - - {newFileName} {fi2.Length}");

      }

      catch (Exception e)

      {

         Console.WriteLine($" - - - - - EXCEPTION {e.Message} {e.StackTrace}");

      }

      return newFileName;

 }

Here is partial output from running the code:

UnzipFile : 177686_2018-10-18_0#289.json.gz 34975

4096

4096

 855

            177686_2018-10-18_0#289.json 9047

So it looks like a file of size 34975 bytes when compressed ends up decompressing only 9047 bytes. If I use gunzip on a mac to expand the file I get a file 223344 bytes in size.

Where have I gone wrong?

edit: Additional data

In case it helps, I get this when using GZip.Decompress

Bad CRC32 in GZIP trailer. (actual(7C64AEAA)!=expected(F641B726)) at Ionic.Zlib.ZlibBaseStream.finish()

Additional data when examining the position of the FileStream

fs pos: 2093 fs len: 33930

edited Nov 15 '18 at 14:32

asked Nov 15 '18 at 1:47

Zain Mecklai

By the way, streams have a CopyTo method :)
– John
Nov 15 '18 at 2:03

Are you able to attach an example input to your code so people can test it?
– mjwills
Nov 15 '18 at 2:23

@mjwills I have proprietary data in the files so that's a blocker for me. I'll see if I can scrub some of it. If it helps, I get it from Amplitude's API amplitude.zendesk.com/hc/en-us/articles/…
– Zain Mecklai
Nov 15 '18 at 2:42

1

@John Thanks! I'll incorporate that! Appreciate the tip.
– Zain Mecklai
Nov 15 '18 at 2:42

add a comment |

I'm trying to read a series of gzip files using the code below.

What I end up with is a file that is only a fraction of the total file. Interestingly enough the text file output is almost perfectly truncated at a line break.

public static string UnzipFile(string filename)

{

    FileInfo fi = new FileInfo(filename);

    Console.WriteLine($" - - - - - UnzipFile {filename} {fi.Length} - - - - - ");

    string newFileName = filename.Substring(0, filename.Length - 4);



    try

    {

       byte buffer = new byte[4096]; // read in chunks of 4KB

       using (FileStream fs2 = new FileStream(newFileName, FileMode.CreateNew))

       {

          using (FileStream fs = new FileStream(filename, FileMode.Open))

          {

             using (GZipStream zipStream = new GZipStream(fs, CompressionMode.Decompress))

             {

                zipStream.BufferSize = 1024;

                int bytesRead;

                while((bytesRead = zipStream.Read(buffer, 0, buffer.Length)) > 0)

                {

                   Console.WriteLine($" {bytesRead}  ");

                   fs2.Write(buffer, 0, bytesRead);

                   fs2.Flush(true);

                }          

             }           

         }

      }

      FileInfo fi2 = new FileInfo(newFileName);

      Console.WriteLine($" - - - - {newFileName} {fi2.Length}");

      }

      catch (Exception e)

      {

         Console.WriteLine($" - - - - - EXCEPTION {e.Message} {e.StackTrace}");

      }

      return newFileName;

 }

Here is partial output from running the code:

UnzipFile : 177686_2018-10-18_0#289.json.gz 34975

4096

4096

 855

            177686_2018-10-18_0#289.json 9047

So it looks like a file of size 34975 bytes when compressed ends up decompressing only 9047 bytes. If I use gunzip on a mac to expand the file I get a file 223344 bytes in size.

Where have I gone wrong?

edit: Additional data

In case it helps, I get this when using GZip.Decompress

Bad CRC32 in GZIP trailer. (actual(7C64AEAA)!=expected(F641B726)) at Ionic.Zlib.ZlibBaseStream.finish()

Additional data when examining the position of the FileStream

fs pos: 2093 fs len: 33930

edited Nov 15 '18 at 14:32

asked Nov 15 '18 at 1:47

Zain Mecklai

I'm trying to read a series of gzip files using the code below.

What I end up with is a file that is only a fraction of the total file. Interestingly enough the text file output is almost perfectly truncated at a line break.

public static string UnzipFile(string filename)

{

    FileInfo fi = new FileInfo(filename);

    Console.WriteLine($" - - - - - UnzipFile {filename} {fi.Length} - - - - - ");

    string newFileName = filename.Substring(0, filename.Length - 4);



    try

    {

       byte buffer = new byte[4096]; // read in chunks of 4KB

       using (FileStream fs2 = new FileStream(newFileName, FileMode.CreateNew))

       {

          using (FileStream fs = new FileStream(filename, FileMode.Open))

          {

             using (GZipStream zipStream = new GZipStream(fs, CompressionMode.Decompress))

             {

                zipStream.BufferSize = 1024;

                int bytesRead;

                while((bytesRead = zipStream.Read(buffer, 0, buffer.Length)) > 0)

                {

                   Console.WriteLine($" {bytesRead}  ");

                   fs2.Write(buffer, 0, bytesRead);

                   fs2.Flush(true);

                }          

             }           

         }

      }

      FileInfo fi2 = new FileInfo(newFileName);

      Console.WriteLine($" - - - - {newFileName} {fi2.Length}");

      }

      catch (Exception e)

      {

         Console.WriteLine($" - - - - - EXCEPTION {e.Message} {e.StackTrace}");

      }

      return newFileName;

 }

Here is partial output from running the code:

UnzipFile : 177686_2018-10-18_0#289.json.gz 34975

4096

4096

 855

            177686_2018-10-18_0#289.json 9047

So it looks like a file of size 34975 bytes when compressed ends up decompressing only 9047 bytes. If I use gunzip on a mac to expand the file I get a file 223344 bytes in size.

Where have I gone wrong?

edit: Additional data

In case it helps, I get this when using GZip.Decompress

Bad CRC32 in GZIP trailer. (actual(7C64AEAA)!=expected(F641B726)) at Ionic.Zlib.ZlibBaseStream.finish()

Additional data when examining the position of the FileStream

fs pos: 2093 fs len: 33930

c# .net gzip sharpziplib

edited Nov 15 '18 at 14:32

asked Nov 15 '18 at 1:47

Zain Mecklai

edited Nov 15 '18 at 14:32

asked Nov 15 '18 at 1:47

Zain Mecklai

edited Nov 15 '18 at 14:32

asked Nov 15 '18 at 1:47

Zain Mecklai

asked Nov 15 '18 at 1:47

Zain Mecklai

asked Nov 15 '18 at 1:47

Zain Mecklai

By the way, streams have a CopyTo method :)
– John
Nov 15 '18 at 2:03

Are you able to attach an example input to your code so people can test it?
– mjwills
Nov 15 '18 at 2:23

@mjwills I have proprietary data in the files so that's a blocker for me. I'll see if I can scrub some of it. If it helps, I get it from Amplitude's API amplitude.zendesk.com/hc/en-us/articles/…
– Zain Mecklai
Nov 15 '18 at 2:42

1

@John Thanks! I'll incorporate that! Appreciate the tip.
– Zain Mecklai
Nov 15 '18 at 2:42

add a comment |

By the way, streams have a CopyTo method :)
– John
Nov 15 '18 at 2:03

Are you able to attach an example input to your code so people can test it?
– mjwills
Nov 15 '18 at 2:23

@mjwills I have proprietary data in the files so that's a blocker for me. I'll see if I can scrub some of it. If it helps, I get it from Amplitude's API amplitude.zendesk.com/hc/en-us/articles/…
– Zain Mecklai
Nov 15 '18 at 2:42

1

@John Thanks! I'll incorporate that! Appreciate the tip.
– Zain Mecklai
Nov 15 '18 at 2:42

By the way, streams have a CopyTo method :)
– John
Nov 15 '18 at 2:03

Are you able to attach an example input to your code so people can test it?
– mjwills
Nov 15 '18 at 2:23

@mjwills I have proprietary data in the files so that's a blocker for me. I'll see if I can scrub some of it. If it helps, I get it from Amplitude's API amplitude.zendesk.com/hc/en-us/articles/…
– Zain Mecklai
Nov 15 '18 at 2:42

@John Thanks! I'll incorporate that! Appreciate the tip.
– Zain Mecklai
Nov 15 '18 at 2:42

add a comment |

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