MiGz未能解压缩GZIP压缩数据 about migz

[jeffpasternack]

Hi--unfortunately, I do not speak Chinese. If possible, could you please restate your issue in English?

[jyf1997]

I used GZIP and MiGz to compress the same data respectively, and found that there are several differences in the data compressed by MiGz. The data are as follows:
GZIP1: 1f8b08000000000000003334323634320400ee129cde06000000
MiGz1: 1f8b080400000000020008004d5a0400080000003334323634320400ee129cde06000000
GZIP2: 1f8b08000000000000002b4b2c4b492c2b4b4c010071ec6fe909000000
MiGz2: 1f8b080400000000020008004d5a04000b0000002b4b2c4b492c2b4b4c010071ec6fe909000000
How can I adjust to keep the data compressed by MiGZ consistent with that of GZIP compression?

[jeffpasternack]

This is expected behavior--MiGz uses a different header than other GZip tools, and may or may not be using the same block compression. However, any GZip program will still be able to decompress a MiGz-compressed file.

Incidentally, other GZip implementations are also free to produce different bytes, so there's no guarantee that two GZip utilities will produce the exact same data when compressing the same file.

[jyf1997]

we have some data compressed using gzip and want to use miGZ， but we are not allowed to ungip and re-miGZ previouse data. Can we still use miGZ to decompress the previouse data that are compressed using gzip? Thanks

[jeffpasternack]

Unfortunately it's not (in general) possible to do multithreaded decompression of data GZipped by standard utilities, so using MiGz would have no benefit in this case, and MiGz consequently does not support decompression of non-MiGz-compressed data.

As an aside, if you have multiple GZipped files you need to read, you might consider unzipping each file in separate thread to achieve a degree of parallelism.