- eliminate 2 allocations in EachKey()

[Villenny]

Description:
Eliminate 2 allocations from EachKey()

Benchmark before change:

BenchmarkEachKey
BenchmarkEachKey-8
  308006	      3885 ns/op	     272 B/op	       3 allocs/op
PASS

Benchmark after change:

BenchmarkEachKey
BenchmarkEachKey-8
  333666	      3674 ns/op	       8 B/op	       1 allocs/op
PASS

Benchmarked with:

func BenchmarkEachKey(b *testing.B) {
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		var id string
		var bidId string
		var bidImpId string
		var bidPrice string
		var bidAdm string
		var cur string
		var foo string

		bodyBytes := stringHelper.StringAsBytes(BidResponse_Banner)

		jsonparser.EachKey(bodyBytes, func(idx int, value []byte, vt jsonparser.ValueType, err error) {
			switch idx {
			case 0:
				id = stringHelper.BytesAsString(value)
			case 1:
				bidId = stringHelper.BytesAsString(value)
			case 2:
				bidImpId = stringHelper.BytesAsString(value)
			case 3:
				bidPrice = stringHelper.BytesAsString(value)
			case 4:
				bidAdm = stringHelper.BytesAsString(value)
			case 5:
				cur = stringHelper.BytesAsString(value)
			case 6:
				foo = stringHelper.BytesAsString(value)
			}
		},
			[][]string{
				{"id"},
				{"seatbid", "[0]", "bid", "[0]", "id"},
				{"seatbid", "[0]", "bid", "[0]", "impid"},
				{"seatbid", "[0]", "bid", "[0]", "price"},
				{"seatbid", "[0]", "bid", "[0]", "adm"},
				{"cur"},
				{"foo"},
			}...,
		)

		if "9f3701ef-1d8a-4b67-a601-e9a1a2fbcb7c" != id ||
			"0" != bidId ||
			"1" != bidImpId ||
			"0.35258" != bidPrice ||
			`some \"html\" code\nnext line` != bidAdm ||
			"USD" != cur ||
			"" != foo {
			panic("ack")
		}
	}

}

const BidResponse_Banner = `
{
	"id":"9f3701ef-1d8a-4b67-a601-e9a1a2fbcb7c",
	"seatbid":[
	   {
		  "bid":[
			 {
				"id":"0",
				"adomain":[
				   "someurl.com",
				   "someotherurl.com"
				],
				"impid":"1",
				"price":0.35258,
				"adm":"some \"html\" code\nnext line",
				"w":300,
				"h":250
			 }
		  ]
	   }
	],
	"cur":"USD"
}
`

[buger]

Nice!

[xsandr]

Looks good!
@Villenny could you please add the fix for pIdxFlags that you've mentioned? or do you prefer to do it separately?

[Villenny]

Looks good!
@Villenny could you please add the fix for pIdxFlags that you've mentioned? or do you prefer to do it separately?

It wouldnt let me edit this pull request, its already done on my repo, in the patch-2 branch. But it wont let me add commits to this once the PR is open, so it will have to be another one.

[buger]

@Villenny sorry for the delay, merged! Can't wait for the second PR :)