Hello, On 15/04/13 23:14, Bo Chen wrote: > SVN uses zlib to compress the new data in delta. By default, the > compression level in the current implementation is 5, right? I am > wondering what are differences by choosing different compression > level? Is is a trade-off between compression rate and computational > overhead?
Yes, obviously. Please read /usr/include/zlib.h, or anything about compression levels? #define Z_NO_COMPRESSION 0 #define Z_BEST_SPEED 1 #define Z_BEST_COMPRESSION 9 #define Z_DEFAULT_COMPRESSION (-1) [...] 1 gives best speed, 9 gives best compression, 0 gives no compression at all (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION requests a default compromise between speed and compression (currently equivalent to level 6). Andreas
