libubus: add logic to reduce msgbuf data size after 16 small messages

[project/ubus.git] / libubus-io.c

diff --git a/libubus-io.c b/libubus-io.c
index c63a9201cd713256ed6616b75427ff4f9087034e..f38403f83b9eef1ff1259778bc7b5cb02d0fdec1 100644 (file)
--- a/libubus-io.c
+++ b/libubus-io.c
@@ -28,6 +28,8 @@
 
 #define STATIC_IOV(_var) { .iov_base = (char *) &(_var), .iov_len = sizeof(_var) }
 
+#define UBUS_MSGBUF_REDUCTION_INTERVAL 16
+
 static const struct blob_attr_info ubus_policy[UBUS_ATTR_MAX] = {
        [UBUS_ATTR_STATUS] = { .type = BLOB_ATTR_INT32 },
        [UBUS_ATTR_OBJID] = { .type = BLOB_ATTR_INT32 },
@@ -233,6 +235,7 @@ static bool get_next_msg(struct ubus_context *ctx, int *recv_fd)
                struct blob_attr data;
        } hdrbuf;
        struct iovec iov = STATIC_IOV(hdrbuf);
+       int len;
        int r;
 
        /* receive header + start attribute */
@@ -247,6 +250,26 @@ static bool get_next_msg(struct ubus_context *ctx, int *recv_fd)
        if (!ubus_validate_hdr(&hdrbuf.hdr))
                return false;
 
+       len = blob_raw_len(&hdrbuf.data);
+       if (len > ctx->msgbuf_data_len) {
+               ctx->msgbuf_reduction_counter = UBUS_MSGBUF_REDUCTION_INTERVAL;
+       } else if (ctx->msgbuf_data_len > UBUS_MSG_CHUNK_SIZE) {
+               if (ctx->msgbuf_reduction_counter > 0) {
+                       len = -1;
+                       --ctx->msgbuf_reduction_counter;
+               } else
+                       len = UBUS_MSG_CHUNK_SIZE;
+       } else
+               len = -1;
+
+       if (len > -1) {
+               ctx->msgbuf.data = realloc(ctx->msgbuf.data, len * sizeof(char));
+               if (ctx->msgbuf.data)
+                       ctx->msgbuf_data_len = len;
+       }
+       if (!ctx->msgbuf.data)
+               return false;
+
        memcpy(&ctx->msgbuf.hdr, &hdrbuf.hdr, sizeof(hdrbuf.hdr));
        memcpy(ctx->msgbuf.data, &hdrbuf.data, sizeof(hdrbuf.data));