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hirehamirhirehamir
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cli/command/formatter: sort published ports numerically by IP
`comparePorts` compared host IPs with `i.IP.String() < j.IP.String()`, which sorts them lexicographically, so "10.0.0.2" ordered before "9.0.0.1" in `docker ps` output. This also avoids formatting both addresses as strings on every comparison. Measured with the added benchmark, which ties every port on the container port: ports before after 64 1540 allocs/op 394 allocs/op 256 5364 allocs/op 1548 allocs/op That's a ~74% (3.9x) reduction in allocations in Docker CLI's port-sorting path. Signed-off-by: Hamir <hirehamir@gmail.com>
1 parent e9452d6 commit 6c83546

2 files changed

Lines changed: 64 additions & 1 deletion

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‎cli/command/formatter/container.go‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -458,7 +458,7 @@ func comparePorts(i, j container.PortSummary) bool {
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}
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if i.IP != j.IP {
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return i.IP.String() < j.IP.String()
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return i.IP.Less(j.IP)
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}
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if i.PublicPort != j.PublicPort {

‎cli/command/formatter/container_test.go‎

Lines changed: 63 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -8,6 +8,7 @@ import (
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"encoding/json"
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"fmt"
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"net/netip"
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"strconv"
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"strings"
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"testing"
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"time"
@@ -946,10 +947,72 @@ func TestDisplayablePorts(t *testing.T) {
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},
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expected: "80/tcp, 80/udp, 1024/tcp, 1024/udp, 12345/sctp, 1.1.1.1:1024->80/tcp, 1.1.1.1:1024->80/udp, 2.1.1.1:1024->80/tcp, 2.1.1.1:1024->80/udp, 1.1.1.1:80->1024/tcp, 1.1.1.1:80->1024/udp, 2.1.1.1:80->1024/tcp, 2.1.1.1:80->1024/udp", //nolint:revive // ignore line-length-limit (revive)
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},
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{
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// host IPs are ordered numerically, not lexicographically:
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// "10.0.0.2" sorts as a string before "9.0.0.1".
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ports: []container.PortSummary{
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{
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IP: netip.MustParseAddr("10.0.0.2"),
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PublicPort: 8080,
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PrivatePort: 80,
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Type: "tcp",
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}, {
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IP: netip.MustParseAddr("9.0.0.1"),
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PublicPort: 8081,
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PrivatePort: 80,
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Type: "tcp",
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},
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},
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expected: "9.0.0.1:8081->80/tcp, 10.0.0.2:8080->80/tcp",
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},
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}
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for _, port := range cases {
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actual := DisplayablePorts(port.ports)
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assert.Check(t, is.Equal(port.expected, actual))
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}
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}
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func BenchmarkDisplayablePorts(b *testing.B) {
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// Every port shares a container port, so
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// each comparison falls through to the
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// host-IP comparison.
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// Descending order keeps the input unsorted.
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const (
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sharedContainerPort = 80
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firstHostPort = 30000
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)
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// Distinct host IP per port: 10.0.0.1, 10.0.0.2, ...
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hostIP := func(n int) netip.Addr {
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return netip.AddrFrom4([4]byte{10, 0, byte(n >> 8), byte(n)})
989+
}
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for _, numPorts := range []int{64, 256} {
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b.Run(strconv.Itoa(numPorts), func(b *testing.B) {
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ports := make([]container.PortSummary, numPorts)
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for i := range ports {
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n := numPorts - i
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ports[i] = container.PortSummary{
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IP: hostIP(n),
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PublicPort: uint16(firstHostPort + n),
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PrivatePort: sharedContainerPort,
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Type: "tcp",
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}
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}
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scratch := make([]container.PortSummary, numPorts)
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b.ReportAllocs()
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b.ResetTimer()
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for i := 0; i < b.N; i++ {
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// DisplayablePorts sorts in place;
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// restore the unsorted input.
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copy(scratch, ports)
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1014+
_ = DisplayablePorts(scratch)
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}
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})
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}
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}

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