snapshot of https://github.com/nats-io/nats-server.git (main, 2026-09-15; blobs > 131072B omitted)

server/sysmem/mem_bsd.go

@@ -0,0 +1,20 @@
+// Copyright 2019-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build freebsd || openbsd || dragonfly || netbsd
+
+package sysmem
+
+func Memory() int64 {
+	return sysctlInt64("hw.physmem")
+}

server/sysmem/mem_darwin.go

@@ -0,0 +1,20 @@
+// Copyright 2019-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build darwin
+
+package sysmem
+
+func Memory() int64 {
+	return sysctlInt64("hw.memsize")
+}

server/sysmem/mem_linux.go

@@ -0,0 +1,27 @@
+// Copyright 2019-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build linux
+
+package sysmem
+
+import "syscall"
+
+func Memory() int64 {
+	var info syscall.Sysinfo_t
+	err := syscall.Sysinfo(&info)
+	if err != nil {
+		return 0
+	}
+	return int64(info.Totalram) * int64(info.Unit)
+}

server/sysmem/mem_solaris.go

@@ -0,0 +1,37 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build illumos || solaris
+
+package sysmem
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+const (
+	_SC_PHYS_PAGES = 500
+	_SC_PAGESIZE   = 11
+)
+
+func Memory() int64 {
+	pages, err := unix.Sysconf(_SC_PHYS_PAGES)
+	if err != nil {
+		return 0
+	}
+	pageSize, err := unix.Sysconf(_SC_PAGESIZE)
+	if err != nil {
+		return 0
+	}
+	return int64(pages) * int64(pageSize)
+}

server/sysmem/mem_wasm.go

@@ -0,0 +1,21 @@
+// Copyright 2022-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build wasm
+
+package sysmem
+
+func Memory() int64 {
+	// TODO: We don't know the system memory
+	return 0
+}

server/sysmem/mem_windows.go

@@ -0,0 +1,51 @@
+// Copyright 2019-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+
+package sysmem
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var winKernel32 = windows.NewLazySystemDLL("kernel32.dll")
+var winGlobalMemoryStatusEx = winKernel32.NewProc("GlobalMemoryStatusEx")
+
+func init() {
+	if err := winKernel32.Load(); err != nil {
+		panic(err)
+	}
+	if err := winGlobalMemoryStatusEx.Find(); err != nil {
+		panic(err)
+	}
+}
+
+// https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-memorystatusex
+type _memoryStatusEx struct {
+	dwLength     uint32
+	dwMemoryLoad uint32
+	ullTotalPhys uint64
+	unused       [6]uint64 // ignore rest of struct
+}
+
+func Memory() int64 {
+	msx := &_memoryStatusEx{dwLength: 64}
+	res, _, _ := winGlobalMemoryStatusEx.Call(uintptr(unsafe.Pointer(msx)))
+	if res == 0 {
+		return 0
+	}
+	return int64(msx.ullTotalPhys)
+}

server/sysmem/mem_zos.go

@@ -0,0 +1,21 @@
+// Copyright 2022-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build zos
+
+package sysmem
+
+func Memory() int64 {
+	// TODO: We don't know the system memory
+	return 0
+}

server/sysmem/sysctl.go

@@ -0,0 +1,33 @@
+// Copyright 2019-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build darwin || freebsd || openbsd || dragonfly || netbsd
+
+package sysmem
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func sysctlInt64(name string) int64 {
+	s, err := syscall.Sysctl(name)
+	if err != nil {
+		return 0
+	}
+	// Make sure it's 8 bytes when we do the cast below.
+	// We were getting fatal error: checkptr: converted pointer straddles multiple allocations in go 1.22.1 on darwin.
+	var b [8]byte
+	copy(b[:], s)
+	return *(*int64)(unsafe.Pointer(&b[0]))
+}