Thanks, it works! -----Original Message----- From: Stefan Bodewig [mailto:bode...@apache.org] Sent: Saturday, September 16, 2017 6:39 PM To: user@commons.apache.org Subject: Re: [compress] uncompress a file containing lz4 stripes
On 2017-09-15, Simo Chiegang, Boris Arthur wrote: > So, we develop a special kind of image file with the following structure: > - Header file [offset 0 to 4096 bytes] > - Stripe 1 [4096 - 20000 bytes] (LZ4 block compressed) > - Empty bloc [20000 - 22000 bytes] > - Stripe 2 [22000 - 35000] (LZ4 block compressed) > - ... > Something like that. So now I want to read this file with the class > BlockLZ4CompressorInputStream. It is possible? In general yes, but probbaly not with a single instance of it (and you may need to adapt something). BlockLZ4CompressorInputStream should be able to read a single block, but it wont be able to detect the end of the LZ4 block unless the underlying stream is exhausted. There is no way to identify the last sequence other than via EOF. If your header contains information about the compressed size of your block(s) then you can wrap the current input stream into a BoundedInputStream that returns EOF once the block has been read completely. You then create a BlockLZ4CompressorInputStream wrapped around the BoundedInputStream - and do this for each stripe. This is pretty much is what FramedLZ4CompressorInputStream does as well. Things get a bit more complex if match offsets of stripe 2 are allowed to point into the contents of stripe 1. FramedLZ4CompressorInputStream handles this in the case where "block dependency" is expected. Stefan --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@commons.apache.org For additional commands, e-mail: user-h...@commons.apache.org ________________________________ Confidentiality note: The information in this email and any attachment may contain confidential and proprietary information of Heidelberger Druckmaschinen AG and/or its affiliates and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, you are hereby notified that any review, reliance or distribution by others or forwarding without express permission is strictly prohibited and may cause liability. In case you have received this message due to an error in transmission, we kindly ask you to notify the sender immediately and to delete this email and any attachment from your system. --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@commons.apache.org For additional commands, e-mail: user-h...@commons.apache.org
