degesch: set a limit on backlog entries

So that buffers don't grow indefinitely in memory.

1 files changed, 11 insertions, 0 deletions

diff --git a/degesch.c b/degesch.c
index 5ac89c1..1ff89c9 100644
--- a/degesch.c
+++ b/degesch.c
@@ -82,6 +82,9 @@ enum
 /// Some arbitrary limit for the history file
 #define HISTORY_LIMIT 10000
 
+/// How many lines of backlog to store in memory
+#define BACKLOG_LIMIT 1000
+
 /// Characters that separate words
 #define WORD_BREAKING_CHARS " \f\n\r\t\v"
 
@@ -2725,6 +2728,14 @@ log_formatter (struct app_context *ctx,
 	if (!buffer)
 		buffer = ctx->global_buffer;
 
+	if (buffer->lines_count >= BACKLOG_LIMIT)
+	{
+		struct buffer_line *popped = buffer->lines;
+		LIST_UNLINK_WITH_TAIL (buffer->lines, buffer->lines_tail, popped);
+		buffer_line_destroy (popped);
+		buffer->lines_count--;
+	}
+
 	struct buffer_line *line = buffer_line_new ();
 	line->flags = flags;
 	line->when = time (NULL);