Publish ITWorx Pulse source

internal/hostcollect/procfs.go

@@ -0,0 +1,67 @@
+package hostcollect
+
+import (
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// readLimited reads at most limit bytes from path. Every /proc file the collector
+// touches is small, but /proc is a kernel interface and a bounded read keeps a
+// pathological or hostile file from becoming an unbounded allocation.
+func readLimited(path string, limit int64) ([]byte, error) {
+	file, err := os.Open(path) //nolint:gosec // paths are derived from the configured procfs root
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = file.Close() }()
+	data, err := io.ReadAll(io.LimitReader(file, limit))
+	if err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func readTrimmed(path string, limit int64) (string, error) {
+	data, err := readLimited(path, limit)
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(string(data)), nil
+}
+
+// parseUint accepts the decimal unsigned values procfs uses and reports failure
+// instead of guessing, so a malformed line degrades one field rather than producing a
+// plausible-looking zero.
+func parseUint(value string) (uint64, bool) {
+	parsed, err := strconv.ParseUint(strings.TrimSpace(value), 10, 64)
+	if err != nil {
+		return 0, false
+	}
+	return parsed, true
+}
+
+func parseFloat(value string) (float64, bool) {
+	parsed, err := strconv.ParseFloat(strings.TrimSpace(value), 64)
+	if err != nil {
+		return 0, false
+	}
+	return parsed, true
+}
+
+func truncate(value string, max int) string {
+	if len(value) > max {
+		return value[:max]
+	}
+	return value
+}
+
+// lines splits procfs content without allocating a scanner per file.
+func lines(data []byte) []string {
+	text := strings.TrimRight(string(data), "\n")
+	if text == "" {
+		return nil
+	}
+	return strings.Split(text, "\n")
+}