On Mon, Jan 30, 2023 at 20:35 PM Akhil Goyal <gak...@marvell.com> wrote: > > > +/** > > + * Block checksum flag. > > + * If this flag is set, each data block will be followed by a 4-bytes > > checksum, > > + * calculated by using the xxHash-32 algorithm on the raw (compressed) data > > + * block. The intention is to detect data corruption (storage or > > transmission > > + * errors) immediately, before decoding. Block checksum usage is optional. > > + */ > > +#define RTE_COMP_LZ4_FLAG_BLOCK_CHECKSUM (1 << 4) > > + > > +/** > > + * Block Independence flag. > > + * If this flag is set to 1, blocks are independent. > > + * If this flag is set to 0, each block depends on previous ones (up to LZ4 > > + * window size, which is 64 KB). In such case, it is necessary to decode > > all > > + * blocks in sequence. > > + * Block dependency improves compression ratio, especially for small > > blocks. > > On > > + * the other hand, it makes random access or multi-threaded decoding > > impossible. > > + */ > > +#define RTE_COMP_LZ4_FLAG_BLOCK_INDEPENDENCE (1 << 5) > > Why did you start with 4th and 5th bit of the flags? Why not first two bits?
I didn't choose the values by myself, I took them from LZ4 standard: https://github.com/lz4/lz4/blob/dev/doc/lz4_Frame_format.md#frame-descriptor > > ++ more people for review.
