It changes the hash and longest match functions to always match at least 4 bytes, instead the 3 the spec allows. It allows for faster and more effective compression because there are less hash collisions, and false matches are discarded faster.
In theory it could lead to worse compression in some cases, but for the most common files there is an improvement for all levels both in speed and in compression ratio.
Merge pull request #1 from cloudflare/match.four

It changes the hash and longest match functions to always match at least 4 bytes, instead the 3 the spec allows. It allows for faster and more effective compression because there are less hash collisions, and false matches are discarded faster.
In theory it could lead to worse compression in some cases, but for the most common files there is an improvement for all levels both in speed and in compression ratio.