netty5

History

Nikolay Fedorovskikh 6ab9c177ac Fix hash function and hash table size in Snappy Motivation: 1. Hash function in the Snappy encoding is wrong probably: used '+' instead of '*'. See the reference implementation [1]. 2. Size of the hash table is calculated, but not applied. Modifications: 1. Fix hash function: replace addition by multiplication. 2. Allocate hash table with calculated size. 3. Use an `Integer.numberOfLeadingZeros` trick for calculate log2. 4. Release buffers in tests. Result: 1. Better compression. In the test `encodeAndDecodeLongTextUsesCopy` now compressed size is 175 instead of 180 before this change. 2. No redundant allocations for hash table. 3. A bit faster the calc of shift (less an expensive math operations). [1] `513df5fb5a/snappy.cc (L67)`	2017-08-01 07:08:54 +02:00
..
src	Fix hash function and hash table size in Snappy	2017-08-01 07:08:54 +02:00
pom.xml	[maven-release-plugin] prepare for next development iteration	2017-07-06 13:24:06 +02:00

Nikolay Fedorovskikh 6ab9c177ac Fix hash function and hash table size in Snappy

Motivation:

1. Hash function in the Snappy encoding is wrong probably: used '+' instead of '*'. See the reference implementation [1].
2. Size of the hash table is calculated, but not applied.

Modifications:

1. Fix hash function: replace addition by multiplication.
2. Allocate hash table with calculated size.
3. Use an `Integer.numberOfLeadingZeros` trick for calculate log2.
4. Release buffers in tests.

Result:

1. Better compression. In the test `encodeAndDecodeLongTextUsesCopy` now compressed size is 175 instead of 180 before this change.
2. No redundant allocations for hash table.
3. A bit faster the calc of shift (less an expensive math operations).

[1] 513df5fb5a/snappy.cc (L67)

2017-08-01 07:08:54 +02:00

src Fix hash function and hash table size in Snappy 2017-08-01 07:08:54 +02:00

pom.xml [maven-release-plugin] prepare for next development iteration 2017-07-06 13:24:06 +02:00