【建议】压缩int的时候，如果是负数，现在实现中的压缩结果有点浪费空间

[imzoer]

void CodedOutputData::writeInt32(int32_t value) { if (value >= 0) { this->writeRawVarint32(value); } else { this->writeRawVarint64(value); } }

不明白为什么要采用现在这种压缩方法。
zigzag 压缩负数的效率应该比 writeRawVarint64 的实现要好一些

[imzoer]

ref : https://blog.csdn.net/zgwangbo/article/details/51590186

[lingol]

And how do you know the value < 0 when decoding? EG, how do you know when to do a un-zigzag when decoding?

To be honest, when MMKV was started, the encoding/decoding code was inspired by the Google official implementation, which will sign-extend negative numbers. If there's a huge call for negative number handling, maybe we should add some SInt32/SInt64 interface.

[imzoer]

If we zigzag all positive and negative numbers, we do not have to care if a number is negative. Just un-zigzag all numbers

[lingol]

And that’s a big if, for breaking existing code/data that relying on not zigzaging positive numbers. You gota think about backward compatibility.