Reduce RedisStateMachine bytecode size

[hellyguo]

Describe the solution you'd like

the method, decode(), in RedisStateMachine is so big. When convert it to bytecode, the size is great than 325 bytes.

Describe alternatives you've considered

using enum with behavior + lambda, we can reduce the method's size.

Teachability, Documentation, Adoption, Migration Strategy

JitWatch

[hellyguo]

before

➜  jitwatch-1.3.0 ./jarScan.sh --mode=maxMethodSize --limit=325 --packages=io.lettuce.core.protocol ~/code/github/lettuce-core/target/classes
"io.lettuce.core.protocol","RedisStateMachine","decode","io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",571

after

➜  jitwatch-1.3.0 ./jarScan.sh --mode=maxMethodSize --limit=5 --packages=io.lettuce.core.protocol ~/code/github/lettuce-core/target/classes|grep -F RedisStateMachine
"io.lettuce.core.protocol","RedisStateMachine","loopPeekStack","io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",127
"io.lettuce.core.protocol","RedisStateMachine","decode","io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",109
"io.lettuce.core.protocol","RedisStateMachine","funcMulti","io.lettuce.core.protocol.RedisStateMachine,io.lettuce.core.protocol.RedisStateMachine$State,io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",100
"io.lettuce.core.protocol","RedisStateMachine","funcBulk","io.lettuce.core.protocol.RedisStateMachine,io.lettuce.core.protocol.RedisStateMachine$State,io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",75
"io.lettuce.core.protocol","RedisStateMachine","funcInteger","io.lettuce.core.protocol.RedisStateMachine,io.lettuce.core.protocol.RedisStateMachine$State,io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",42
"io.lettuce.core.protocol","RedisStateMachine","funcSingle","io.lettuce.core.protocol.RedisStateMachine,io.lettuce.core.protocol.RedisStateMachine$State,io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",39
"io.lettuce.core.protocol","RedisStateMachine","funcBytes","io.lettuce.core.protocol.RedisStateMachine,io.lettuce.core.protocol.RedisStateMachine$State,io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",32
"io.lettuce.core.protocol","RedisStateMachine","funcError","io.lettuce.core.protocol.RedisStateMachine,io.lettuce.core.protocol.RedisStateMachine$State,io.netty.buffer.ByteBuf,io.lettuce.core.protocol.RedisCommand<?, ?, ?>,io.lettuce.core.output.CommandOutput<?, ?, ?>",28

[mp911de]

Can you explain the motivation behind this change?

[hellyguo]

I'm working on a business project now. In my project, I need a fast 3rd lib to access redis. I may use some asynchronous scenarios. What lettuce has is What I needed.

I compared jedis and lettuce. After a simple(may be wrong) test, I found lettuce is not the fast one in my test.

I captured the thread dump. Found RedisStateMachine. Then I read the code, found the method.

My motivation is let lettuce run faster. But just a tiny improve.

• reduce the method(decode), more readable, less bytecode size
• split in several methods, may some is tiny enough that can be inline
• prefer to use enum-interface-lambda, not switch-case

like what netty did

[mp911de]

Thanks a lot. I'll have a look.

[mp911de]

That's merged now.