review queryBuilder func

[neda1985]

@fzerorubigd can you please review this func it looks a bit crazy :( actually elastic query should look like this : {"query": { "bool" : { "must" : [ {"term" : { "genres.name" :{"value ":"genre" } }, {"term" : { "moods.name": {"value ":"moods" } }, {"term" : { "has_vocal" : {"value ":"hasVocal" } } , ] } } } }

[fzerorubigd]

it's not that bad, just a few notes :

https://github.com/neda1985/search/blob/d7b1902c74c71fd81b43c333b27adefdbc7e1148/main.go#L136

Generally, its better to not create an empty array with make, jsut go for var must []match but in this situation I suggest doing it this way: must := make([]match, 0, 3) adding capacity when you know the size beforehand is the best practice.

Another approach is instead of using map, use struct. Define your structure based on the JSON you want (this tool can help https://mholt.github.io/json-to-go/ ) and it is much faster and memory-efficient that way.

[neda1985]

I remove must := make([]match, 0)

[neda1985]

will refactor again and get back to you thanks :)

[fzerorubigd]

I remove must := make([]match, 0)

Since you know at max you are going to add 3 elements to this slice, I suggest this change : must := make([]math, 0, 3)

[neda1985]

ok yeah make way more sense

[neda1985]

correct me if I am wrong must := make([]match, 0) would allocate unnecessary memory right ? but when we define size just the defined one will be allocated

[fzerorubigd]

Actually No. var x []string defines a variable x, with nil as its value, next time you want to append value to it, it allocates the array (under any slice there is an array in Go)

x := make([]string,0) define a variable x but the value is an empty slice, it allocate an empty array (it's empty, but it occupies memory, next time when you want to append a value to it, it has to allocate once more, so the first allocation is kind of pointless)

x := make([]string,0,3) it allocates at the beginning, but it is empty. the capacity is 3, so for the first 3 appends, there are no allocations. this is the best when you know the size of slice at first.

[neda1985]

ahhhhhhhh , thanks for explanation , got it