Re: [Squashfs-devel] [PATCH] adding compression level option to mksquashfs

[Lucas C. V. R. <lu...@go...>]

On Thu, Jul 31, 2008 at 5:37 AM, Geert Uytterhoeven
<Gee...@so...> wrote:
> On Tue, 8 Jul 2008, Lucas C. Villa Real wrote:
>> This patch allows one to specify which compression level to use when
>> creating a squashfs image with mksquashfs. When no option is given the
>> default compression level is used, so the default behaviour is kept.
>> This feature has shown to be very useful while I was working in a
>> platform with limited resources, so I believe others might find it
>> useful as well.
>
> [ converted attachment to inline for easier commenting ]
>
>> Adds -compressionLevel option to mksquashfs.
>>
>> Signed-off-by: Lucas C. Villa Real <lu...@go...>
>>
>> --- squashfs-tools/mksquashfs.c.orig  2008-07-04 12:41:58.000000000 -0300
>> +++ squashfs-tools/mksquashfs.c       2008-07-08 12:19:23.000000000 -0300
>> @@ -3398,6 +3398,17 @@ int main(int argc, char *argv[])
>>                                       exit(1);
>>                               }
>>                       }
>> +             } else if(strcmp(argv[i], "-compressionLevel") == 0) {
>> +                     if(++i == argc) {
>> +                             ERROR("%s: -compressionLevel requires a parameter\n", argv[0]);
>> +                             exit(1);
>> +                     }
>> +                     cLevel = atoi(argv[i]);
>> +                     if (cLevel != -1 && cLevel != 0 && cLevel != 1 && cLevel != 9) {
>> +                             ERROR("%s: -compressionLevel out of range\n", argv[0]);
>> +                             exit(1);
>> +                     }
>> +                     printf("using compression level %d\n", cLevel);
>>               } else if(strcmp(argv[i], "-noI") == 0 ||
>>                               strcmp(argv[i], "-noInodeCompression") == 0)
>>                       noI = TRUE;
>> @@ -3480,6 +3491,8 @@ printOptions:
>>                       ERROR("-nopad\t\t\tdo not pad filesystem to a multiple of 4K\n");
>>                       ERROR("-check_data\t\tadd checkdata for greater filesystem checks\n");
>>                       ERROR("-root-owned\t\talternative name for -all-root\n");
>> +                     ERROR("-compressionLevel\tzlib compression level. Valid values are -1(default),\n");
>> +                     ERROR("\t\t\t0(no compression), 1(best speed) and 9(best compression)\n");
>>                       ERROR("-noInodeCompression\talternative name for -noI\n");
>>                       ERROR("-noDataCompression\talternative name for -noD\n");
>>                       ERROR("-noFragmentCompression\talternative name for -noF\n");
>
> Just wondering, why do you limit the possible values of cLevel?

Ooops, my bad! I probably just took the definitions from zlib.h and
blindly limited the code to use those values.

Please consider the attached patch instead. Thanks for the review!

Regards,
Lucas