1 files changed, 105 insertions, 0 deletions
diff --git a/vendor/github.com/KimMachineGun/automemlimit/memlimit/memlimit.go b/vendor/github.com/KimMachineGun/automemlimit/memlimit/memlimit.go
new file mode 100644
index 000000000..7b49bb33b
--- /dev/null
+++ b/vendor/github.com/KimMachineGun/automemlimit/memlimit/memlimit.go
@@ -0,0 +1,105 @@
+package memlimit
+
+import (
+	"errors"
+	"io"
+	"log"
+	"math"
+	"os"
+	"runtime/debug"
+	"strconv"
+)
+
+const (
+	envGOMEMLIMIT         = "GOMEMLIMIT"
+	envAUTOMEMLIMIT       = "AUTOMEMLIMIT"
+	envAUTOMEMLIMIT_DEBUG = "AUTOMEMLIMIT_DEBUG"
+
+	defaultAUTOMEMLIMIT = 0.9
+)
+
+var (
+	// ErrNoLimit is returned when the memory limit is not set.
+	ErrNoLimit = errors.New("memory is not limited")
+	// ErrNoCgroup is returned when the process is not in cgroup.
+	ErrNoCgroup = errors.New("process is not in cgroup")
+	// ErrCgroupsNotSupported is returned when the system does not support cgroups.
+	ErrCgroupsNotSupported = errors.New("cgroups is not supported on this system")
+
+	logger = log.New(io.Discard, "", log.LstdFlags)
+)
+
+// SetGoMemLimitWithEnv sets GOMEMLIMIT with the value from the environment variable.
+// You can configure how much memory of the cgroup's memory limit to set as GOMEMLIMIT
+// through AUTOMEMLIMIT in the half-open range (0.0,1.0].
+//
+// If AUTOMEMLIMIT is not set, it defaults to 0.9. (10% is the headroom for memory sources the Go runtime is unaware of.)
+// If GOMEMLIMIT is already set or AUTOMEMLIMIT=off, this function does nothing.
+func SetGoMemLimitWithEnv() {
+	if os.Getenv(envAUTOMEMLIMIT_DEBUG) == "true" {
+		logger = log.Default()
+	}
+
+	if val, ok := os.LookupEnv(envGOMEMLIMIT); ok {
+		logger.Printf("GOMEMLIMIT is set already, skipping: %s\n", val)
+		return
+	}
+
+	ratio := defaultAUTOMEMLIMIT
+	if val, ok := os.LookupEnv(envAUTOMEMLIMIT); ok {
+		if val == "off" {
+			logger.Printf("AUTOMEMLIMIT is set to off, skipping\n")
+			return
+		}
+		_ratio, err := strconv.ParseFloat(val, 64)
+		if err != nil {
+			logger.Printf("cannot parse AUTOMEMLIMIT: %s\n", val)
+			return
+		}
+		ratio = _ratio
+	}
+	if ratio <= 0 || ratio > 1 {
+		logger.Printf("invalid AUTOMEMLIMIT: %f\n", ratio)
+		return
+	}
+
+	limit, err := SetGoMemLimit(ratio)
+	if err != nil {
+		logger.Printf("failed to set GOMEMLIMIT: %v\n", err)
+		return
+	}
+
+	logger.Printf("GOMEMLIMIT=%d\n", limit)
+}
+
+// SetGoMemLimit sets GOMEMLIMIT with the value from the cgroup's memory limit and given ratio.
+func SetGoMemLimit(ratio float64) (int64, error) {
+	return SetGoMemLimitWithProvider(FromCgroup, ratio)
+}
+
+// Provider is a function that returns the memory limit.
+type Provider func() (uint64, error)
+
+// SetGoMemLimitWithProvider sets GOMEMLIMIT with the value from the given provider and ratio.
+func SetGoMemLimitWithProvider(provider Provider, ratio float64) (int64, error) {
+	limit, err := provider()
+	if err != nil {
+		return 0, err
+	}
+	goMemLimit := cappedFloat2Int(float64(limit) * ratio)
+	debug.SetMemoryLimit(goMemLimit)
+	return goMemLimit, nil
+}
+
+func cappedFloat2Int(f float64) int64 {
+	if f > math.MaxInt64 {
+		return math.MaxInt64
+	}
+	return int64(f)
+}
+// Limit is a helper Provider function that returns the given limit.
+func Limit(limit uint64) func() (uint64, error) {
+	return func() (uint64, error) {
+		return limit, nil
+	}
+}