From ff16ac27f598edf678bba3c3e703d5ce414968fc Mon Sep 17 00:00:00 2001
From: Richard Fuchs <rfuchs@sipwise.com>
Date: Wed, 8 Jan 2025 10:35:07 -0400
Subject: [PATCH] MT#61822 support on-demand loading to FS cache

Change-Id: Ifce951e52710fdb12ccb0de5d1a110b6f05a9873
---
 daemon/media_player.c | 33 ++++++++++++++++++++++++++-------
 docs/rtpengine.md     |  3 ++-
 etc/rtpengine.conf    |  2 +-
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/daemon/media_player.c b/daemon/media_player.c
index 2197f8d00..b3dea6c51 100644
--- a/daemon/media_player.c
+++ b/daemon/media_player.c
@@ -1227,11 +1227,20 @@ static struct media_player_media_file *media_player_media_file_read_str(const st
 	return media_player_media_file_read_c(file_s);
 }
 
-static const char *media_player_get_db_id(str *out, unsigned long long id, str (*dup_fn)(const char *, size_t));
+static const char *media_player_get_db_id(str *out, unsigned long long id,
+		str (*dup_fn)(const char *, size_t),
+		void (*cache_fn)(const char *s, size_t len, unsigned long long id));
+
+static void media_player_add_cache_file_dummy(const char *s, size_t len, unsigned long long id) {
+}
+
+static void (*media_player_add_cache_file)(const char *s, size_t len, unsigned long long id) =
+	media_player_add_cache_file_dummy;
+
 
 static struct media_player_media_file *media_player_db_id_read(unsigned long long id) {
 	str blob;
-	const char *err = media_player_get_db_id(&blob, id, str_dup_len);
+	const char *err = media_player_get_db_id(&blob, id, str_dup_len, media_player_add_cache_file);
 	if (err || blob.len == 0)
 		return NULL;
 	return media_player_media_file_new(blob);
@@ -1759,7 +1768,7 @@ static char *media_player_make_cache_entry_name(unsigned long long id) {
 	return g_strdup_printf("%s/%llu.blob", rtpe_config.db_media_cache, id);
 }
 
-static void media_player_add_cache_file(const char *s, size_t len, unsigned long long id) {
+static void media_player_add_cache_file_create(const char *s, size_t len, unsigned long long id) {
 	if (!rtpe_config.db_media_cache)
 		return;
 
@@ -1776,7 +1785,9 @@ static str dummy_dup(const char *s, size_t l) {
 	return STR_NULL;
 }
 
-static const char *media_player_get_db_id(str *out, unsigned long long id, str (*dup_fn)(const char *, size_t))
+static const char *media_player_get_db_id(str *out, unsigned long long id,
+		str (*dup_fn)(const char *, size_t),
+		void (*cache_fn)(const char *s, size_t len, unsigned long long id))
 {
 	const char *err;
 	g_autoptr(char) query = NULL;
@@ -1822,7 +1833,7 @@ success:;
 		goto err;
 	}
 
-	media_player_add_cache_file(row[0], lengths[0], id);
+	cache_fn(row[0], lengths[0], id);
 
 	*out = dup_fn(row[0], lengths[0]);
 	return NULL;
@@ -1868,7 +1879,7 @@ static mp_cached_code __media_player_add_db(struct media_player *mp,
 			g_free(buf);
 	}
 
-	err = media_player_get_db_id(&opts.blob, opts.db_id, call_str_cpy_len);
+	err = media_player_get_db_id(&opts.blob, opts.db_id, call_str_cpy_len, media_player_add_cache_file);
 	if (err)
 		return MPC_ERR;
 
@@ -2450,6 +2461,13 @@ bool media_player_preload_cache(char **ids) {
 
 	for (char **idp = ids; *idp; idp++) {
 		char *id_s = *idp;
+		while (*id_s == ' ')
+			id_s++;
+
+		if (!strcmp(id_s, "ondemand") || !strcmp(id_s, "on demand") || !strcmp(id_s, "on-demand")) {
+			media_player_add_cache_file = media_player_add_cache_file_create;
+			continue;
+		}
 
 		char *endp = NULL;
 		unsigned long long id = strtoull(id_s, &endp, 0);
@@ -2461,7 +2479,8 @@ bool media_player_preload_cache(char **ids) {
 		ilog(LOG_DEBUG, "Reading media ID %llu from DB for caching", id);
 
 		str out;
-		const char *err = media_player_get_db_id(&out, id, dummy_dup);
+		const char *err = media_player_get_db_id(&out, id, dummy_dup,
+				media_player_add_cache_file_create);
 		if (err)
 			return false; // error has been logged already
 	}
diff --git a/docs/rtpengine.md b/docs/rtpengine.md
index 173221679..bbc0585d9 100644
--- a/docs/rtpengine.md
+++ b/docs/rtpengine.md
@@ -1202,7 +1202,8 @@ call to inject-DTMF won't be sent to __\-\-dtmf-log-dest=__ or __\-\-listen-tcp-
 - __\-\-preload-db-cache=__*INT*
 
     Similar to __preload-db-media__ but populates the filesystem-backed cache
-    instead of storing the media in memory.
+    instead of storing the media in memory. On-demand loading is also
+    supported.
 
 - __\-\-audio-buffer-length=__*INT*
 
diff --git a/etc/rtpengine.conf b/etc/rtpengine.conf
index 2b6ae711b..bab3b6355 100644
--- a/etc/rtpengine.conf
+++ b/etc/rtpengine.conf
@@ -170,7 +170,7 @@ recording-method = proc
 # preload-db-media = 1; 2; 3; 4; on-demand
 # db-media-reload = 3600
 # db-media-cache = /var/cache/rtpengine
-# preload-db-cache = 1; 2; 3; 4
+# preload-db-cache = 1; 2; 3; 4; on-demand
 
 # signalling templates (see key `templates` above)
 [templates]