filter_multiline: address PR feedback

Signed-off-by: Wesley Pettit <wppttt@amazon.com>

plugins/filter_multiline/ml.c

@@ -169,6 +169,7 @@ static int flush_callback(struct flb_ml_parser *parser,
         }
 
         /* Emit record with original tag */
+        flb_plg_trace(ctx->ins, "emitting from %s to %s", stream->input_name, stream->tag);
         ret = in_emitter_add_record(stream->tag, flb_sds_len(stream->tag), buf_data, buf_size,
                                     ctx->ins_emitter);
 
@@ -201,8 +202,12 @@ static int cb_ml_init(struct flb_filter_instance *ins,
      * Config map is not yet set at this point in the code
      * user must explicitly set buffer to false to turn it off 
      */
+    ctx->use_buffer = FLB_TRUE;
     tmp = (char *) flb_filter_get_property("buffer", ins);
-    if (tmp && (strcasecmp(tmp, "Off") == 0 || strcasecmp(tmp, "false") == 0)) {
+    if (tmp) {
+        ctx->use_buffer = flb_utils_bool(tmp);
+    }
+    if (ctx->use_buffer == FLB_FALSE) {
             /* Init buffers */
             msgpack_sbuffer_init(&ctx->mp_sbuf);
             msgpack_packer_init(&ctx->mp_pck, &ctx->mp_sbuf, msgpack_sbuffer_write);
@@ -229,13 +234,14 @@ static int cb_ml_init(struct flb_filter_instance *ins,
             tmp = flb_sds_printf(&emitter_name, "emitter_for_%s",
                                 flb_filter_name(ins));
             if (!tmp) {
-                flb_error("[filter multiline] cannot compose emitter_name");
+                flb_plg_error(ins, "cannot compose emitter_name");
                 flb_sds_destroy(emitter_name);
                 flb_free(ctx);
                 return -1;
             }
 
             flb_filter_set_property(ins, "emitter_name", emitter_name);
+            flb_plg_info(ins, "created emitter: %s", emitter_name);
             flb_sds_destroy(emitter_name);
         }
     }
@@ -270,6 +276,7 @@ static int cb_ml_init(struct flb_filter_instance *ins,
         /* Create the emitter context */
         ret = emitter_create(ctx);
         if (ret == -1) {
+            flb_free(ctx);
             return -1;
         }
 
@@ -353,7 +360,6 @@ static struct ml_stream *get_by_id(struct ml_ctx *ctx, uint64_t stream_id)
     mk_list_foreach_safe(head, tmp, &ctx->ml_streams) {
         stream = mk_list_entry(head, struct ml_stream, _head);
         if (stream->stream_id == stream_id) {
-            flb_debug("emitting to %s_%s", stream->input_name, stream->tag);
             return stream;
         }
     }
@@ -381,7 +387,7 @@ static struct ml_stream *get_or_create_stream(struct ml_ctx *ctx,
         name_check = strcmp(stream->input_name, i_ins->name);
         tag_check = strcmp(stream->tag, tag);
         if (tag_check == 0 && name_check == 0) {
-            flb_debug("debug: using stream %s_%s", stream->input_name, stream->tag);
+            flb_plg_trace(ctx->ins, "using stream %s_%s", stream->input_name, stream->tag);
             return stream;
         }
     }
@@ -514,7 +520,7 @@ static int cb_ml_filter(const void *data, size_t bytes,
 
     } else { /* buffered mode */
         if (i_ins == ctx->ins_emitter) {
-            flb_plg_debug(ctx->ins, "not processing record from the emitter");
+            flb_plg_trace(ctx->ins, "not processing record from the emitter");
             return FLB_FILTER_NOTOUCH;
         }