Restructure to put all the streaming code in one place.

bin/varnishd/cache/cache_req_fsm.c

@@ -79,43 +79,102 @@ DOT acceptor -> recv [style=bold,color=green]
  * We have a refcounted object on the session, and possibly the busyobj
  * which is fetching it, prepare a response.
  *
-DOT subgraph xcluster_prepresp {
-DOT	prepresp [
+DOT	stream [
 DOT		shape=record
-DOT		label="{cnt_prepresp:|Filter obj.-\>resp.|{vcl_deliver\{\}|{req.|resp.}}|{error?|restart?}|stream ?}"
+DOT		label="{cnt_stream:}"
 DOT	]
-DOT	prepresp -> deliver [style=bold,color=green,label=deliver]
-DOT	prepresp -> deliver [style=bold,color=red]
-DOT	prepresp -> deliver [style=bold,color=blue]
-DOT }
+DOT	stream:deliver:s -> DONE [style=bold,color=red]
+DOT	stream:deliver:s -> DONE [style=bold,color=blue]
  *
  */
 
 static enum req_fsm_nxt
-cnt_prepresp(struct worker *wrk, struct req *req)
+cnt_stream(struct worker *wrk, struct req *req)
 {
 	struct busyobj *bo;
 
 	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
 	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
 	bo = req->busyobj;
-	CHECK_OBJ_ORNULL(bo, BUSYOBJ_MAGIC);
+	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
 
 	CHECK_OBJ_NOTNULL(req->obj, OBJECT_MAGIC);
 	CHECK_OBJ_NOTNULL(req->vcl, VCL_CONF_MAGIC);
 
 	req->res_mode = 0;
 
-	if (bo == NULL) {
-		if (!req->disable_esi && req->obj->esidata != NULL) {
-			/* In ESI mode, we can't know the aggregate length */
-			req->res_mode &= ~RES_LEN;
-			req->res_mode |= RES_ESI;
-		} else {
-			req->res_mode |= RES_LEN;
-		}
+	AZ(bo->do_esi);
+
+	if (wrk->handling == VCL_RET_RESTART) {
+		AN(bo->do_stream);
+		assert(req->obj == bo->fetch_obj);
+		req->obj = NULL;
+		VBO_DerefBusyObj(wrk, &req->busyobj);
+		AZ(req->obj);
+		http_Teardown(req->resp);
+		req->req_step = R_STP_RESTART;
+		return (REQ_FSM_MORE);
+	}
+	assert(wrk->handling == VCL_RET_DELIVER);
+
+	while (bo->state < BOS_FAILED)
+		(void)usleep(10000);
+	assert(bo->state >= BOS_FAILED);
+
+	if (bo->state == BOS_FAILED) {
+		(void)HSH_Deref(&wrk->stats, NULL, &req->obj);
+		VBO_DerefBusyObj(wrk, &req->busyobj);
+		req->err_code = 503;
+		req->req_step = R_STP_ERROR;
+		return (REQ_FSM_MORE);
+	}
+	VBO_DerefBusyObj(wrk, &req->busyobj);
+
+	AZ(req->busyobj);
+
+	RES_WriteObj(req);
+
+	/* No point in saving the body if it is hit-for-pass */
+	if (req->obj->objcore->flags & OC_F_PASS)
+		STV_Freestore(req->obj);
+
+	assert(WRW_IsReleased(wrk));
+	(void)HSH_Deref(&wrk->stats, NULL, &req->obj);
+	http_Teardown(req->resp);
+	return (REQ_FSM_DONE);
+}
+
+/*--------------------------------------------------------------------
+ * Deliver an already stored object
+ *
+DOT	deliver [
+DOT		shape=record
+DOT		label="{cnt_deliver:|Filter obj.-\>resp.|{vcl_deliver\{\}|{req.|resp.}}|{<stream>deliver(stream)?|restart?|<deliver>deliver?}}"
+DOT	]
+DOT deliver:deliver:s -> DONE [style=bold,color=green]
+DOT deliver:stream:s -> stream [style=bold,color=red]
+DOT deliver:stream:s -> stream [style=bold,color=blue]
+ *
+ */
+
+static enum req_fsm_nxt
+cnt_deliver(struct worker *wrk, struct req *req)
+{
+
+	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
+	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
+	CHECK_OBJ_NOTNULL(req->obj, OBJECT_MAGIC);
+	CHECK_OBJ_NOTNULL(req->vcl, VCL_CONF_MAGIC);
+
+	req->res_mode = 0;
+
+	if (!req->disable_esi && req->obj->esidata != NULL) {
+		AZ(req->busyobj);
+		/* In ESI mode, we can't know the aggregate length */
+		req->res_mode &= ~RES_LEN;
+		req->res_mode |= RES_ESI;
 	} else {
-		AZ(bo->do_esi);
+		req->res_mode |= RES_LEN;
 	}
 
 	if (req->esi_level > 0) {
@@ -159,75 +218,24 @@ cnt_prepresp(struct worker *wrk, struct req *req)
 	RES_BuildHttp(req);
 
 	VCL_deliver_method(req->vcl, wrk, req, NULL, req->http->ws);
-	switch (wrk->handling) {
-	case VCL_RET_DELIVER:
-		break;
-	case VCL_RET_RESTART:
-		if (req->restarts >= cache_param->max_restarts)
-			break;
-		if (bo != NULL) {
-			AN(bo->do_stream);
-			assert(req->obj == bo->fetch_obj);
-			req->obj = NULL;
-			VBO_DerefBusyObj(wrk, &req->busyobj);
-		} else {
-			(void)HSH_Deref(&wrk->stats, NULL, &req->obj);
-		}
+
+	/* Stop the insanity before it turns "Hotel California" on us */
+	if (req->restarts >= cache_param->max_restarts)
+		wrk->handling = VCL_RET_DELIVER;
+
+	if (req->busyobj != NULL) {
+		req->req_step = R_STP_STREAM;
+		return (REQ_FSM_MORE);
+	}
+
+	if (wrk->handling == VCL_RET_RESTART) {
+		(void)HSH_Deref(&wrk->stats, NULL, &req->obj);
 		AZ(req->obj);
 		http_Teardown(req->resp);
 		req->req_step = R_STP_RESTART;
 		return (REQ_FSM_MORE);
-	default:
-		WRONG("Illegal action in vcl_deliver{}");
 	}
-	req->req_step = R_STP_DELIVER;
-	return (REQ_FSM_MORE);
-}
-
-/*--------------------------------------------------------------------
- * Deliver an already stored object
- *
-DOT subgraph xcluster_deliver {
-DOT	deliver [
-DOT		shape=record
-DOT		label="{cnt_deliver:|Send body}"
-DOT	]
-DOT }
-DOT deliver -> DONE [style=bold,color=green]
-DOT deliver -> DONE [style=bold,color=red]
-DOT deliver -> DONE [style=bold,color=blue]
- *
- */
-
-static enum req_fsm_nxt
-cnt_deliver(struct worker *wrk, struct req *req)
-{
-	struct busyobj *bo;
-
-	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
-	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
-	CHECK_OBJ_NOTNULL(req->obj, OBJECT_MAGIC);
-	bo = req->busyobj;
-	CHECK_OBJ_ORNULL(bo, BUSYOBJ_MAGIC);
-
-	if (bo != NULL) {
-		while (bo->state < BOS_FAILED)
-			(void)usleep(10000);
-		assert(bo->state >= BOS_FAILED);
-
-		if (bo->state == BOS_FAILED) {
-			(void)HSH_Deref(&wrk->stats, NULL, &req->obj);
-			VBO_DerefBusyObj(wrk, &req->busyobj);
-			req->err_code = 503;
-			req->req_step = R_STP_ERROR;
-			return (REQ_FSM_MORE);
-		}
-		VBO_DerefBusyObj(wrk, &req->busyobj);
-	}
-
-	AZ(req->busyobj);
-	req->director = NULL;
-	req->restarts = 0;
+	assert(wrk->handling == VCL_RET_DELIVER);
 
 	RES_WriteObj(req);
 
@@ -240,6 +248,7 @@ cnt_deliver(struct worker *wrk, struct req *req)
 	http_Teardown(req->resp);
 	return (REQ_FSM_DONE);
 }
+
 /*--------------------------------------------------------------------
  * Emit an error
  *
@@ -249,7 +258,7 @@ DOT		shape=record
 DOT		label="vcl_error()|resp."
 DOT	]
 DOT	ERROR -> vcl_error
-DOT	vcl_error-> prepresp [label=deliver]
+DOT	vcl_error-> deliver [label=deliver]
 DOT }
 DOT vcl_error-> rsterr [label="restart",color=purple]
 DOT rsterr [label="RESTART",shape=plaintext]
@@ -312,15 +321,16 @@ cnt_error(struct worker *wrk, struct req *req)
 		http_PutResponse(h, http_StatusMessage(req->err_code));
 	VCL_error_method(req->vcl, wrk, req, NULL, req->http->ws);
 
-	if (wrk->handling == VCL_RET_RESTART &&
-	    req->restarts <  cache_param->max_restarts) {
+	/* Stop the insanity before it turns "Hotel California" on us */
+	if (req->restarts >= cache_param->max_restarts)
+		wrk->handling = VCL_RET_DELIVER;
+
+	if (wrk->handling == VCL_RET_RESTART) {
 		HSH_Drop(wrk, &req->obj);
 		VBO_DerefBusyObj(wrk, &req->busyobj);
 		req->req_step = R_STP_RESTART;
 		return (REQ_FSM_MORE);
-	} else if (wrk->handling == VCL_RET_RESTART)
-		wrk->handling = VCL_RET_DELIVER;
-
+	}
 
 	/* We always close when we take this path */
 	req->doclose = SC_TX_ERROR;
@@ -331,7 +341,7 @@ cnt_error(struct worker *wrk, struct req *req)
 	req->err_reason = NULL;
 	http_Teardown(bo->bereq);
 	VBO_DerefBusyObj(wrk, &req->busyobj);
-	req->req_step = R_STP_PREPRESP;
+	req->req_step = R_STP_DELIVER;
 	return (REQ_FSM_MORE);
 }
 
@@ -344,8 +354,8 @@ DOT		shape=record
 DOT		label="{cnt_fetch:|start fetch_thread}"
 DOT	]
 DOT }
-DOT fetch -> prepresp [style=bold,color=red]
-DOT fetch -> prepresp [style=bold,color=blue]
+DOT fetch -> deliver [style=bold,color=red]
+DOT fetch -> deliver [style=bold,color=blue]
  */
 
 static enum req_fsm_nxt
@@ -373,7 +383,7 @@ cnt_fetch(struct worker *wrk, struct req *req)
 		req->obj = req->busyobj->fetch_obj;
 		VBO_DerefBusyObj(wrk, &req->busyobj);
 		assert(WRW_IsReleased(wrk));
-		req->req_step = R_STP_PREPRESP;
+		req->req_step = R_STP_DELIVER;
 	}
 	return (REQ_FSM_MORE);
 }
@@ -403,7 +413,7 @@ DOT lookup:eb:s -> lookup2 [style=bold,color=green]
 DOT lookup:h:s -> lookup2 [style=bold,color=green]
 DOT lookup2:pass:s -> pass [style=bold,color=red]
 DOT lookup2:fetch:s -> miss [style=bold,color=blue]
-DOT lookup2:deliver:s -> prepresp:nw [style=bold,color=green]
+DOT lookup2:deliver:s -> deliver:n [style=bold,color=green]
  */
 
 static enum req_fsm_nxt
@@ -496,7 +506,7 @@ cnt_lookup(struct worker *wrk, struct req *req)
 			(void)HTTP1_DiscardReqBody(req);// XXX: handle err
 		}
 		wrk->stats.cache_hit++;
-		req->req_step = R_STP_PREPRESP;
+		req->req_step = R_STP_DELIVER;
 		return (REQ_FSM_MORE);
 	case VCL_RET_FETCH:
 		(void)HSH_Deref(&wrk->stats, NULL, &req->obj);

include/tbl/steps.h

@@ -44,7 +44,7 @@ REQ_STEP(lookup,	LOOKUP,		(wrk, req))
 REQ_STEP(purge,		PURGE,		(wrk, req))
 REQ_STEP(miss,		MISS,		(wrk, req))
 REQ_STEP(fetch,		FETCH,		(wrk, req))
-REQ_STEP(prepresp,	PREPRESP,	(wrk, req))
+REQ_STEP(stream,	STREAM,		(wrk, req))
 REQ_STEP(deliver,	DELIVER,	(wrk, req))
 REQ_STEP(error,		ERROR,		(wrk, req))
 #endif