Allow to write to temporary spaces in read-only mode

Closes #1378

src/box/box.cc

@@ -119,12 +119,11 @@ box_check_slab_alloc_minimal(ssize_t slab_alloc_minimal)
 }
 
 void
-process_rw(struct request *request, struct tuple **result)
+process_rw(struct request *request, struct space *space, struct tuple **result)
 {
 	assert(iproto_type_is_dml(request->type));
 	rmean_collect(rmean_box, request->type, 1);
 	try {
-		struct space *space = space_cache_find(request->space_id);
 		struct txn *txn = txn_begin_stmt(space);
 		access_check_space(space, PRIV_W);
 		struct tuple *tuple;
@@ -207,7 +206,8 @@ apply_row(struct xstream *stream, struct xrow_header *row)
 	request_decode_xc(request, (const char *) row->body[0].iov_base,
 			  row->body[0].iov_len);
 	request->header = row;
-	process_rw(request, NULL);
+	struct space *space = space_cache_find(request->space_id);
+	process_rw(request, space, NULL);
 }
 
 struct wal_stream {
@@ -536,7 +536,8 @@ boxk(enum iproto_type type, uint32_t space_id, const char *format, ...)
 	default:
 		unreachable();
 	}
-	process_rw(request, NULL);
+	struct space *space = space_cache_find(space_id);
+	process_rw(request, space, NULL);
 }
 
 int
@@ -599,8 +600,11 @@ int
 box_process1(struct request *request, box_tuple_t **result)
 {
 	try {
-		box_check_writable();
-		process_rw(request, result);
+		/* Allow to write to temporary spaces in read-only mode. */
+		struct space *space = space_cache_find(request->space_id);
+		if (!space->def.opts.temporary)
+			box_check_writable();
+		process_rw(request, space, result);
 		return 0;
 	} catch (Exception *e) {
 		return -1;

test/box/temp_spaces.result

@@ -72,6 +72,33 @@ s.temporary
 ---
 - true
 ...
+-- check that temporary space can be modified in read-only mode (gh-1378)
+box.cfg{read_only=true}
+---
+...
+box.cfg.read_only
+---
+- true
+...
+s:insert{2, 3, 4}
+---
+- [2, 3, 4]
+...
+s:get{2}
+---
+- [2, 3, 4]
+...
+s:len()
+---
+- 2
+...
+box.cfg{read_only=false}
+---
+...
+box.cfg.read_only
+---
+- false
+...
 env = require('test_run')
 ---
 ...

test/box/temp_spaces.test.lua

@@ -28,6 +28,15 @@ s.temporary
 _ = _space:update(s.id, {{'=', FLAGS, ''}})
 s.temporary
 
+-- check that temporary space can be modified in read-only mode (gh-1378)
+box.cfg{read_only=true}
+box.cfg.read_only
+s:insert{2, 3, 4}
+s:get{2}
+s:len()
+box.cfg{read_only=false}
+box.cfg.read_only
+
 env = require('test_run')
 test_run = env.new()
 test_run:cmd('restart server default')