From 59f8778c32190bf11a6b8fa8c51953b4aadb1780 Mon Sep 17 00:00:00 2001
From: Egor Taranov <dev@taranovegor.com>
Date: Tue, 25 Jun 2024 22:50:04 +0200
Subject: [PATCH] journal: ability to set flags for journal instance

---
 sdjournal/journal.go | 18 +++++++++++++++++-
 sdjournal/read.go    | 11 +++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/sdjournal/journal.go b/sdjournal/journal.go
index 300b4850..65b9a6c0 100644
--- a/sdjournal/journal.go
+++ b/sdjournal/journal.go
@@ -372,6 +372,16 @@ const (
 	SD_JOURNAL_FIELD_CURSOR              = "__CURSOR"
 	SD_JOURNAL_FIELD_REALTIME_TIMESTAMP  = "__REALTIME_TIMESTAMP"
 	SD_JOURNAL_FIELD_MONOTONIC_TIMESTAMP = "__MONOTONIC_TIMESTAMP"
+
+	// Journal Flags
+	SD_JOURNAL_FLAG_LOCAL_ONLY                = int(C.SD_JOURNAL_LOCAL_ONLY)
+	SD_JOURNAL_FLAG_RUNTIME_ONLY              = int(C.SD_JOURNAL_RUNTIME_ONLY)
+	SD_JOURNAL_FLAG_SYSTEM                    = int(C.SD_JOURNAL_SYSTEM)
+	SD_JOURNAL_FLAG_CURRENT_USER              = int(C.SD_JOURNAL_CURRENT_USER)
+	SD_JOURNAL_FLAG_OS_ROOT                   = int(C.SD_JOURNAL_OS_ROOT)
+	SD_JOURNAL_FLAG_ALL_NAMESPACES            = int(C.SD_JOURNAL_ALL_NAMESPACES)
+	SD_JOURNAL_FLAG_INCLUDE_DEFAULT_NAMESPACE = int(C.SD_JOURNAL_INCLUDE_DEFAULT_NAMESPACE)
+	SD_JOURNAL_FLAG_TAKE_DIRECTORY_FD         = int(C.SD_JOURNAL_TAKE_DIRECTORY_FD)
 )
 
 // Journal event constants
@@ -422,6 +432,12 @@ func (m *Match) String() string {
 
 // NewJournal returns a new Journal instance pointing to the local journal
 func NewJournal() (j *Journal, err error) {
+	return NewJournalWithFlags(SD_JOURNAL_FLAG_LOCAL_ONLY)
+}
+
+// NewJournalWithFlags return a new Journal instance pointing to the local journal
+// with a list of flags indicating the scope and type of entries that will be accessed.
+func NewJournalWithFlags(flags int) (j *Journal, err error) {
 	j = &Journal{}
 
 	sd_journal_open, err := getFunction("sd_journal_open")
@@ -429,7 +445,7 @@ func NewJournal() (j *Journal, err error) {
 		return nil, err
 	}
 
-	r := C.my_sd_journal_open(sd_journal_open, &j.cjournal, C.SD_JOURNAL_LOCAL_ONLY)
+	r := C.my_sd_journal_open(sd_journal_open, &j.cjournal, C.int(flags))
 
 	if r < 0 {
 		return nil, fmt.Errorf("failed to open journal: %s", syscall.Errno(-r).Error())
diff --git a/sdjournal/read.go b/sdjournal/read.go
index 51a060fb..4b7ea732 100644
--- a/sdjournal/read.go
+++ b/sdjournal/read.go
@@ -15,6 +15,7 @@
 
 package sdjournal
 
+import "C"
 import (
 	"errors"
 	"fmt"
@@ -48,6 +49,10 @@ type JournalReaderConfig struct {
 	// in this directory. The supplied path may be relative or absolute.
 	Path string
 
+	// If not nil, the journal instance will point to a journal with a list
+	// of flags indicating the scope and type of entries that will be accessed.
+	Flags []int
+
 	// If not nil, Formatter will be used to translate the resulting entries
 	// into strings. If not set, the default format (timestamp and message field)
 	// will be used. If Formatter returns an error, Read will stop and return the error.
@@ -78,6 +83,12 @@ func NewJournalReader(config JournalReaderConfig) (*JournalReader, error) {
 	var err error
 	if config.Path != "" {
 		r.journal, err = NewJournalFromDir(config.Path)
+	} else if len(config.Flags) > 0 {
+		flags := config.Flags[0]
+		for i := 1; i < len(config.Flags); i++ {
+			flags |= config.Flags[i]
+		}
+		r.journal, err = NewJournalWithFlags(flags)
 	} else {
 		r.journal, err = NewJournal()
 	}