From 8507e15f29902a11e0b753d3239c1681394a5ede Mon Sep 17 00:00:00 2001
From: Jonathan Harvey-Buschel <j.s.harbus@gmail.com>
Date: Mon, 26 Aug 2024 17:04:37 -0400
Subject: [PATCH] main: add logcompressor flag

---
 config.go | 12 ++++++++++++
 doc.go    |  2 ++
 log.go    | 28 ++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/config.go b/config.go
index 9bbce7f69a..c5a206976a 100644
--- a/config.go
+++ b/config.go
@@ -41,6 +41,7 @@ const (
 	defaultLogLevel              = "info"
 	defaultLogDirname            = "logs"
 	defaultLogFilename           = "btcd.log"
+	defaultLogCompressor         = Gzip
 	defaultMaxPeers              = 125
 	defaultBanDuration           = time.Hour * 24
 	defaultBanThreshold          = 100
@@ -125,6 +126,7 @@ type config struct {
 	FreeTxRelayLimit     float64       `long:"limitfreerelay" description:"Limit relay of transactions with no transaction fee to the given amount in thousands of bytes per minute"`
 	Listeners            []string      `long:"listen" description:"Add an interface/port to listen for connections (default all interfaces port: 8333, testnet: 18333)"`
 	LogDir               string        `long:"logdir" description:"Directory to log output."`
+	LogCompressor        string        `long:"logcompressor" description:"Compression algorithm to use when rotating logs." choice:"gzip" choice:"zstd"`
 	MaxOrphanTxs         int           `long:"maxorphantx" description:"Max number of orphan transactions to keep in memory"`
 	MaxPeers             int           `long:"maxpeers" description:"Max number of inbound and outbound peers"`
 	MiningAddrs          []string      `long:"miningaddr" description:"Add the specified payment address to the list of addresses to use for generated blocks -- At least one address is required if the generate option is set"`
@@ -428,6 +430,7 @@ func loadConfig() (*config, []string, error) {
 		RPCMaxConcurrentReqs: defaultMaxRPCConcurrentReqs,
 		DataDir:              defaultDataDir,
 		LogDir:               defaultLogDir,
+		LogCompressor:        defaultLogCompressor,
 		DbType:               defaultDbType,
 		RPCKey:               defaultRPCKeyFile,
 		RPCCert:              defaultRPCCertFile,
@@ -661,6 +664,15 @@ func loadConfig() (*config, []string, error) {
 		os.Exit(0)
 	}
 
+	// Validate that the selected log compression algorithm is supported.
+	if !supportedCompressor(cfg.LogCompressor) {
+		str := "%s: The specified log compressor [%v] is invalid"
+		err := fmt.Errorf(str, funcName, cfg.LogCompressor)
+		fmt.Fprintln(os.Stderr, err)
+		fmt.Fprintln(os.Stderr, usageMessage)
+		return nil, nil, err
+	}
+
 	// Initialize log rotation.  After log rotation has been initialized, the
 	// logger variables may be used.
 	initLogRotator(filepath.Join(cfg.LogDir, defaultLogFilename))
diff --git a/doc.go b/doc.go
index 47e4e626b7..6972f23baf 100644
--- a/doc.go
+++ b/doc.go
@@ -76,6 +76,8 @@ Application Options:
 	                            (default all interfaces port: 8333, testnet:
 	                            18333, signet: 38333)
 	    --logdir=               Directory to log output
+	    --logcompressor=        Compression algorithm to use when rotating logs.
+				    (default: gzip)
 	    --maxorphantx=          Max number of orphan transactions to keep in
 	                            memory (default: 100)
 	    --maxpeers=             Max number of inbound and outbound peers
diff --git a/log.go b/log.go
index 5707d7c23a..dcac10b350 100644
--- a/log.go
+++ b/log.go
@@ -105,6 +105,27 @@ var subsystemLoggers = map[string]btclog.Logger{
 	"TXMP": txmpLog,
 }
 
+// Declare the supported compressors as exported consts for easier use from
+// other projects.
+const (
+	Gzip = "gzip"
+	Zstd = "zstd"
+)
+
+// logCompressors maps the identifier for each supported compression algorithm
+// to the extension used for the compressed log files.
+var logCompressors = map[string]string{
+	Gzip: "gz",
+	Zstd: "zst",
+}
+
+// supportedCompressor checks that the named compressor is known and supported
+// for use during log rotation.
+func supportedCompressor(compressor string) bool {
+	_, ok := logCompressors[compressor]
+	return ok
+}
+
 // initLogRotator initializes the logging rotater to write logs to logFile and
 // create roll files in the same directory.  It must be called before the
 // package-global log rotater variables are used.
@@ -121,6 +142,13 @@ func initLogRotator(logFile string) {
 		os.Exit(1)
 	}
 
+	// Reject unknown compressors.
+	if !supportedCompressor(cfg.LogCompressor) {
+		fmt.Fprintf(os.Stderr, "specified log compressor [%v] is "+
+			"invalid", cfg.LogCompressor)
+		os.Exit(1)
+	}
+
 	logRotator = r
 }