Add AIX meminfo

Signed-off-by: Johannes Ziemke <github@5pi.de>

collector/meminfo.go

@@ -11,8 +11,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build (darwin || linux || openbsd || netbsd) && !nomeminfo
-// +build darwin linux openbsd netbsd
+//go:build (darwin || linux || openbsd || netbsd || aix) && !nomeminfo
+// +build darwin linux openbsd netbsd aix
 // +build !nomeminfo
 
 package collector

collector/meminfo_aix.go

@@ -0,0 +1,47 @@
+// Copyright 2024 The Prometheus 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 !nomeminfo
+// +build !nomeminfo
+
+package collector
+
+import (
+	"log/slog"
+
+	"github.com/power-devops/perfstat"
+)
+
+type meminfoCollector struct {
+	logger *slog.Logger
+}
+
+// NewMeminfoCollector returns a new Collector exposing memory stats.
+func NewMeminfoCollector(logger *slog.Logger) (Collector, error) {
+	return &meminfoCollector{
+		logger: logger,
+	}, nil
+}
+
+func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
+	stats, err := perfstat.MemoryTotalStat()
+	if err != nil {
+		return nil, err
+	}
+
+	return map[string]float64{
+		"total_bytes":     float64(stats.RealTotal * 4096),
+		"free_bytes":      float64(stats.RealFree * 4096),
+		"available_bytes": float64(stats.RealAvailable * 4096),
+	}, nil
+}