Increased memory consumption when serializing long slices.

When serializing long slices, increased memory consumption is possible, mine exceeds 3 gigabytes! Steps to reproduce: save this

package main

import (
    "fmt"
    "os"

    "github.com/goccy/go-yaml"
)

type TOC struct {
    StatisticsEntries []MetadataEntry
}

type MetadataEntry struct {
    Name  string
    Value string
    Other string
}

func panicOnErr(err error) {
    if err != nil {
        panic(err)
    }
}

func main() {
    toc := TOC{}
    size := 1000000
    for i := 0; i < size; i++ {
        name := fmt.Sprintf("Name %v", i)
        value := fmt.Sprintf("Value %v", i)
        toc.StatisticsEntries = append(toc.StatisticsEntries, MetadataEntry{Name: name, Value: value})
    }
    fmt.Println("press enter 1")
    var s string
    fmt.Scanf("%s", &s)
    file, _ := os.OpenFile("test.yaml", os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
    defer file.Close()
    enc := yaml.NewEncoder(file)
    defer enc.Close()
    err := enc.Encode(toc)
    panicOnErr(err)
    fmt.Println("press enter 2")
    fmt.Scanf("%s", &s)
}

to file test.go and run it

go run test.go 
press enter 1

press enter 2

bash-4.2$ GODEBUG=gctrace=1 go run my.go
GODEBUG=gctrace=1 go run my.go
gc 1 @0.002s 2%: 0.018+0.34+0.031 ms clock, 0.29+0.061/0.49/0.026+0.49 ms cpu, 3->4->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 2 @0.006s 2%: 0.012+0.21+0.009 ms clock, 0.19+0.050/0.59/0.47+0.14 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 3 @0.008s 4%: 0.089+0.32+0.091 ms clock, 1.4+0.18/0.84/0.45+1.4 ms cpu, 3->4->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 4 @0.011s 7%: 0.38+0.63+0.013 ms clock, 6.2+0.77/1.2/0.031+0.22 ms cpu, 3->4->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 5 @0.013s 7%: 0.066+0.35+0.005 ms clock, 1.0+0.38/1.1/0.099+0.086 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 6 @0.014s 8%: 0.029+0.30+0.005 ms clock, 0.47+0.33/0.78/0.025+0.091 ms cpu, 3->4->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 7 @0.014s 8%: 0.031+0.27+0.026 ms clock, 0.51+0.045/0.71/0.54+0.41 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 8 @0.016s 8%: 0.011+0.24+0.008 ms clock, 0.18+0.034/0.64/0.73+0.14 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 9 @0.019s 7%: 0.010+0.29+0.007 ms clock, 0.16+0.027/0.78/0.80+0.12 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 10 @0.020s 7%: 0.044+0.32+0.006 ms clock, 0.71+0.35/0.64/0+0.10 ms cpu, 3->4->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 11 @0.021s 7%: 0.016+0.34+0.083 ms clock, 0.25+0.049/0.75/0.43+1.3 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 12 @0.022s 7%: 0.045+0.27+0.009 ms clock, 0.72+0/0.69/0+0.15 ms cpu, 3->4->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 13 @0.022s 7%: 0.011+0.23+0.009 ms clock, 0.18+0.031/0.55/0.24+0.14 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 14 @0.023s 8%: 0.048+0.40+0.061 ms clock, 0.77+0.057/0.65/0.48+0.99 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 15 @0.040s 5%: 0.026+0.29+0.008 ms clock, 0.42+0.040/0.82/0.73+0.13 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
# command-line-arguments
gc 1 @0.000s 5%: 0.007+0.27+0.004 ms clock, 0.11+0.084/0.55/0+0.077 ms cpu, 4->6->5 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 2 @0.002s 4%: 0.008+0.31+0.008 ms clock, 0.14+0.052/0.97/0.002+0.12 ms cpu, 14->14->12 MB, 14 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 1 @0.003s 1%: 0.009+0.40+0.005 ms clock, 0.15+0.30/0.10/0+0.089 ms cpu, 3->3->1 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 2 @0.005s 2%: 0.008+1.0+0.020 ms clock, 0.13+0/1.0/0.23+0.32 ms cpu, 4->4->2 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 3 @0.008s 2%: 0.009+1.8+0.005 ms clock, 0.15+0/2.2/0+0.090 ms cpu, 6->6->3 MB, 6 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 4 @0.013s 2%: 0.010+0.84+0.005 ms clock, 0.16+0.11/1.4/0+0.090 ms cpu, 6->6->4 MB, 7 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 5 @0.017s 3%: 0.008+2.6+0.036 ms clock, 0.14+0.19/3.1/0.24+0.58 ms cpu, 12->12->6 MB, 12 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 6 @0.024s 3%: 0.008+0.85+0.010 ms clock, 0.12+0.027/2.7/0.003+0.17 ms cpu, 12->13->8 MB, 13 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 7 @0.034s 3%: 0.022+5.8+0.005 ms clock, 0.35+0.75/5.6/1.0+0.090 ms cpu, 24->24->12 MB, 24 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 8 @0.047s 3%: 0.009+1.2+0.009 ms clock, 0.15+0.093/4.4/0+0.15 ms cpu, 24->24->16 MB, 25 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 9 @0.062s 2%: 0.018+5.8+0.008 ms clock, 0.28+0.040/5.9/0+0.12 ms cpu, 31->32->21 MB, 32 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 10 @0.082s 3%: 0.014+10+0.009 ms clock, 0.23+0.15/13/5.8+0.15 ms cpu, 59->60->30 MB, 60 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 11 @0.112s 2%: 0.016+15+0.010 ms clock, 0.27+5.8/7.0/0.004+0.16 ms cpu, 59->60->39 MB, 61 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 12 @0.156s 2%: 0.017+11+0.008 ms clock, 0.28+4.0/8.7/2.0+0.14 ms cpu, 77->78->51 MB, 79 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 13 @0.202s 2%: 0.018+24+0.006 ms clock, 0.29+1.5/31/7.4+0.098 ms cpu, 146->146->74 MB, 146 MB goal, 0 MB stacks, 0 MB globals, 16 P
press enter 1

gc 14 @33.816s 0%: 0.017+10+0.009 ms clock, 0.27+1.4/39/45+0.14 ms cpu, 144->149->122 MB, 148 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 15 @33.976s 0%: 0.018+19+0.010 ms clock, 0.29+0.061/66/113+0.16 ms cpu, 240->248->201 MB, 245 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 16 @34.232s 0%: 0.019+27+0.010 ms clock, 0.31+0.067/96/228+0.16 ms cpu, 386->395->322 MB, 404 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 17 @34.640s 0%: 0.037+39+0.022 ms clock, 0.59+0.088/155/425+0.35 ms cpu, 617->629->513 MB, 645 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 18 @35.280s 0%: 0.019+70+0.011 ms clock, 0.30+0.077/260/660+0.18 ms cpu, 984->1006->825 MB, 1028 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 19 @36.306s 0%: 0.020+114+0.012 ms clock, 0.32+0/415/1166+0.20 ms cpu, 1581->1607->1320 MB, 1650 MB goal, 0 MB stacks, 0 MB globals, 16 P
gc 20 @38.481s 0%: 0.020+140+0.011 ms clock, 0.33+0.040/561/1533+0.19 ms cpu, 2534->2553->1793 MB, 2641 MB goal, 0 MB stacks, 0 MB globals, 16 P
press enter 2

goccy / go-yaml

Increased memory consumption when serializing long slices. #451