On (04/03/18 19:13), Vaneet Narang wrote: > Hi Sergey, > > >You shrink a 2 bytes offset down to a 1 byte offset, thus you enforce that > 2 Byte offset is not shrinked to 1 byte, Its only 1 bit is reserved out of > 16 bits of offset. So only 15 Bits can be used to store offset value. Yes, you are right. My bad, was thinking about something else. > >'page should be less than 32KB', which I'm sure will be confusing. > lz4_dyn will work on bigger data length(> 32k) but in that case compression > ratio may not be better than LZ4. This is same as LZ4 compressing data more > than 64K (16Bits). LZ4 can't store offset more than 64K similarly > LZ4 dyn can't store offset more than 32K. Then drop that `if PAGE_SIZE' thing. I'd rather do that stuff internally in lz4... if it needed at all. > >And you > >rely on lz4_dyn users to do the right thing - namely, to use that 'nice' > >`#if (PAGE_SIZE < (32 * KB))'. > They don't need to add this code Then drop it. > >Apart from that, lz4_dyn supports only data > >in up to page_size chunks. Suppose my system has page_size of less than 32K, > >so I legitimately can enable lz4_dyn, but suppose that I will use it > >somewhere where I don't work with page_size-d chunks. Will I able to just > >do tfm->compress(src, sz) on random buffers? The whole thing looks to be > >quite fragile. > No thats not true, lz4_dyn can work for random buffers and it need not be > of page size chunks. There is no difference in Lz4 and Lz4 dyn working. You are right. -ss
