Golang\u3067\u3069\u3093\u306a\u66f8\u304d\u65b9\u3092\u3059\u308b\u306e\u304c\u3044\u3044\u306e\u304b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u6307\u6a19\u306b\u3057\u3066\u307f\u3088\u3046\uff01\u3068\u3044\u3046\u3053\u3068\u3067\u30d9\u30f3\u30c1\u30de\u30fc\u30af\u3092\u53d6\u3063\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n
*_test.go\u3067\u30d5\u30a1\u30a4\u30eb\u3092\u4f5c\u6210\u3057\u307e\u3059\u3002
\n\u4eca\u56de\u306f\u6587\u5b57\u5217\u9023\u7d50\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u8a08\u6e2c\u304c\u3057\u305f\u3044\u306e\u3067\u4ee5\u4e0b\u306e\u611f\u3058\u306e\u30b3\u30fc\u30c9\u3092\u66f8\u304d\u307e\u3059\u3002<\/p>\n
package main\r\n\r\nimport \"testing\"\r\n\r\nfunc BenchmarkMemAllocBeforeCustom(b *testing.B) {\r\n n := 10\r\n b.ResetTimer()\r\n for i := 0; i < b.N; i++ {\r\n s := \"\"\r\n for j := 0; j < n; j++ {\r\n s = s + \"alice\"\r\n }\r\n }\r\n}\r\n\r\nfunc BenchmarkMemAllocCustom(b *testing.B) {\r\n n := 10\r\n b.ResetTimer()\r\n for i := 0; i < b.N; i++ {\r\n s := make([]byte, 0)\r\n for j := 0; j < n; j++ {\r\n s = append(s, \"alice\"...)\r\n }\r\n }\r\n}\r\n<\/code><\/pre>\n\u30d9\u30f3\u30c1\u30de\u30fc\u30af\u306e\u5b9f\u884c<\/h2>\n
\u30d9\u30f3\u30c1\u30de\u30fc\u30af\u306e\u5b9f\u884c\u306f\u4ee5\u4e0b\u306e\u30b3\u30de\u30f3\u30c9\u3067\u884c\u3044\u307e\u3059\u3002<\/p>\n
$ go test -bench .\r\nPASS\r\nBenchmarkMemAllocBeforeCustom-4 2000000 815 ns\/op \r\nBenchmarkMemAllocCustom-4 5000000 373 ns\/op\r\nok bench-test 4.669s\r\n<\/code><\/pre>\n\u4ed6\u306b\u3082\u30aa\u30d7\u30b7\u30e7\u30f3\u3064\u3051\u305f\u308a\u3067\u304d\u307e\u3059\u3002<\/p>\n
$ go test -bench . -benchmem\r\nPASS\r\nBenchmarkMemAllocBeforeCustom-4 2000000 815 ns\/op 336 B\/op 9 allocs\/op\r\nBenchmarkMemAllocCustom-4 5000000 373 ns\/op 120 B\/op 4 allocs\/op\r\nok bench-test 4.669s\r\n<\/code><\/pre>\n\u306a\u3093\u304b\u8b0e\u306e\u6570\u5024\u304c\u4e26\u3093\u3067\u307e\u3059\u304c\u3001-benchmem\u306e\u7d50\u679c\u3092\u7c21\u5358\u306b\u8aac\u660e\u3059\u308b\u3068\u4ee5\u4e0b\u306a\u611f\u3058\u3067\u3059\u3002<\/p>\n
\/\/ \u95a2\u6570\u306e\u5b9f\u884c\u56de\u6570\u3001\u6709\u7528\u306a\u7d50\u679c\u304c\u5f97\u3089\u308c\u308b\u307e\u3067\u5b9f\u884c\u3055\u308c\u308b\r\n\/\/ \u591a\u3051\u308c\u3070\u591a\u3044\u307b\u3069\u826f\u3044\r\n2000000\r\n\r\n\/\/ \uff11\u56de\u306e\u5b9f\u884c\u306b\u304b\u304b\u3063\u305f\u6642\u9593\r\n\/\/ \u5c11\u306a\u3044\u307b\u3069\u826f\u3044\r\n815 ns\/op\r\n\r\n\/\/ \u5b9f\u884c\u3054\u3068\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u305f\u30e1\u30e2\u30ea\u306e\u30b5\u30a4\u30ba\r\n\/\/ \u5c11\u306a\u3044\u307b\u3069\u826f\u3044\r\n336 B\/op\r\n\r\n\/\/ \uff11\u56de\u306e\u5b9f\u884c\u3067\u30e1\u30e2\u30ea\u30a2\u30ed\u30b1\u30fc\u30b7\u30e7\u30f3\u304c\u884c\u308f\u308c\u305f\u56de\u6570\r\n\/\/ \u5c11\u306a\u3044\u307b\u3069\u826f\u3044\r\n9 allocs\/op\r\n<\/code><\/pre>\n\u30d9\u30f3\u30c1\u30de\u30fc\u30af\u306e\u7d50\u679c\u306e\u898b\u65b9\u304c\u5206\u304b\u3089\u306a\u304f\u306a\u3063\u305f\u3089\u3053\u306e\u8fba\u306eBenchmarkStruct\u306b\u610f\u5473\u304c\u66f8\u3044\u3066\u3042\u308b\u3063\u307d\u3044\u306e\u3067\u8aad\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
[\u8ffd\u8a18\uff1a2019\/02\/27]<\/p>\n
Go1.12\u306b\u306a\u3063\u305f\u3053\u3068\u3067\u3061\u3087\u3053\u3063\u3068\u5909\u66f4\u304c\u52a0\u308f\u308a\u307e\u3057\u305f\u3002
\n