1 files changed, 78 insertions, 18 deletions

diff --git a/core/upb_stream_vtbl.h b/core/upb_stream_vtbl.h
index d017177..e462122 100644
--- a/core/upb_stream_vtbl.h
+++ b/core/upb_stream_vtbl.h
@@ -13,6 +13,7 @@
 
 #include <assert.h>
 #include "upb_stream.h"
+#include "upb_string.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -21,10 +22,8 @@ extern "C" {
 // Typedefs for function pointers to all of the virtual functions.
 
 // upb_src
-struct _upb_src {
-};
-typedef struct {
-} upb_src_vtbl;
+typedef void (*upb_src_sethandlers_fptr)(upb_src *src, upb_handlers *handlers);
+typedef void (*upb_src_run_fptr)(upb_src *src, upb_status *status);
 
 // upb_bytesrc.
 typedef upb_strlen_t (*upb_bytesrc_read_fptr)(
@@ -42,42 +41,65 @@ typedef upb_strlen_t (*upb_bytesink_putstr_fptr)(
 typedef struct {
   upb_bytesrc_read_fptr   read;
   upb_bytesrc_getstr_fptr getstr;
-} upb_bytesrc_vtable;
+} upb_bytesrc_vtbl;
 
 typedef struct {
   upb_bytesink_write_fptr  write;
   upb_bytesink_putstr_fptr putstr;
-} upb_bytesink_vtable;
+} upb_bytesink_vtbl;
+
+typedef struct {
+  upb_src_sethandlers_fptr sethandlers;
+  upb_src_run_fptr         run;
+} upb_src_vtbl;
+
 
 // "Base Class" definitions; components that implement these interfaces should
 // contain one of these structures.
 
 struct _upb_bytesrc {
-  upb_bytesrc_vtable *vtbl;
+  upb_bytesrc_vtbl *vtbl;
   upb_status status;
   bool eof;
 };
 
 struct _upb_bytesink {
-  upb_bytesink_vtable *vtbl;
+  upb_bytesink_vtbl *vtbl;
   upb_status status;
   bool eof;
 };
 
-INLINE void upb_bytesrc_init(upb_bytesrc *s, upb_bytesrc_vtable *vtbl) {
+struct _upb_src {
+  upb_src_vtbl *vtbl;
+};
+
+INLINE void upb_bytesrc_init(upb_bytesrc *s, upb_bytesrc_vtbl *vtbl) {
   s->vtbl = vtbl;
   s->eof = false;
   upb_status_init(&s->status);
 }
 
-INLINE void upb_bytesink_init(upb_bytesink *s, upb_bytesink_vtable *vtbl) {
+INLINE void upb_bytesink_init(upb_bytesink *s, upb_bytesink_vtbl *vtbl) {
   s->vtbl = vtbl;
   s->eof = false;
   upb_status_init(&s->status);
 }
 
+INLINE void upb_src_init(upb_src *s, upb_src_vtbl *vtbl) {
+  s->vtbl = vtbl;
+}
+
 // Implementation of virtual function dispatch.
 
+// upb_src
+INLINE void upb_src_sethandlers(upb_src *src, upb_handlers *handlers) {
+  src->vtbl->sethandlers(src, handlers);
+}
+
+INLINE void upb_src_run(upb_src *src, upb_status *status) {
+  src->vtbl->run(src, status);
+}
+
 // upb_bytesrc
 INLINE upb_strlen_t upb_bytesrc_read(upb_bytesrc *src, void *buf,
                                      upb_strlen_t count) {
@@ -152,7 +174,41 @@ INLINE bool upb_handlers_isempty(upb_handlers *h) {
   return !h->set && !h->closure;
 }
 
+INLINE upb_flow_t upb_nop(void *closure) {
+  (void)closure;
+  return UPB_CONTINUE;
+}
+
+INLINE upb_flow_t upb_value_nop(void *closure, struct _upb_fielddef *f, upb_value val) {
+  (void)closure;
+  (void)f;
+  (void)val;
+  return UPB_CONTINUE;
+}
+
+INLINE upb_flow_t upb_startsubmsg_nop(void *closure, struct _upb_fielddef *f,
+                                      upb_handlers *delegate_to) {
+  (void)closure;
+  (void)f;
+  (void)delegate_to;
+  return UPB_CONTINUE;
+}
+
+INLINE upb_flow_t upb_unknownval_nop(void *closure, upb_field_number_t fieldnum,
+                                     upb_value val) {
+  (void)closure;
+  (void)fieldnum;
+  (void)val;
+  return UPB_CONTINUE;
+}
+
 INLINE void upb_register_handlerset(upb_handlers *h, upb_handlerset *set) {
+  if (!set->startmsg) set->startmsg = &upb_nop;
+  if (!set->endmsg) set->endmsg = &upb_nop;
+  if (!set->value) set->value = &upb_value_nop;
+  if (!set->startsubmsg) set->startsubmsg = &upb_startsubmsg_nop;
+  if (!set->endsubmsg) set->endsubmsg = &upb_nop;
+  if (!set->unknownval) set->unknownval = &upb_unknownval_nop;
   h->set = set;
 }
 
@@ -182,16 +238,19 @@ INLINE void upb_dispatcher_reset(upb_dispatcher *d, upb_handlers *h) {
   d->top->handlers = *h;
 }
 
-INLINE void upb_dispatch_startmsg(upb_dispatcher *d) {
+INLINE upb_flow_t upb_dispatch_startmsg(upb_dispatcher *d) {
   assert(d->stack == d->top);
-  d->top->handlers.set->startmsg(d->top->handlers.closure);
+  return d->top->handlers.set->startmsg(d->top->handlers.closure);
 }
 
-INLINE void upb_dispatch_endmsg(upb_dispatcher *d) {
+INLINE upb_flow_t upb_dispatch_endmsg(upb_dispatcher *d) {
   assert(d->stack == d->top);
-  d->top->handlers.set->endmsg(d->top->handlers.closure);
+  return d->top->handlers.set->endmsg(d->top->handlers.closure);
 }
 
+// TODO: several edge cases to fix:
+// - delegated start returns UPB_BREAK, should replay the start on resume.
+// - endsubmsg returns UPB_BREAK, should NOT replay the delegated endmsg.
 INLINE upb_flow_t upb_dispatch_startsubmsg(upb_dispatcher *d,
                                            struct _upb_fielddef *f) {
   upb_handlers handlers;
@@ -203,17 +262,18 @@ INLINE upb_flow_t upb_dispatch_startsubmsg(upb_dispatcher *d,
     ++d->top;
     d->top->handlers = handlers;
     d->top->depth = 0;
-    d->top->handlers.set->startmsg(d->top->handlers.closure);
-    ret = UPB_CONTINUE;
+    ret = d->top->handlers.set->startmsg(d->top->handlers.closure);
   }
-  ++d->top->depth;
+  if (ret == UPB_CONTINUE) ++d->top->depth;
   upb_handlers_uninit(&handlers);
   return ret;
 }
 
 INLINE upb_flow_t upb_dispatch_endsubmsg(upb_dispatcher *d) {
+  upb_flow_t ret;
   if (--d->top->depth == 0) {
-    d->top->handlers.set->endmsg(d->top->handlers.closure);
+    ret = d->top->handlers.set->endmsg(d->top->handlers.closure);
+    if (ret != UPB_CONTINUE) return ret;
     --d->top;
   }
   return d->top->handlers.set->endsubmsg(d->top->handlers.closure);