diff options
author | Joshua Haberman <jhaberman@gmail.com> | 2018-08-21 14:18:53 -0700 |
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committer | GitHub <noreply@github.com> | 2018-08-21 14:18:53 -0700 |
commit | e3eae33fb5840dbec3c2bc9109fa164f6066baa8 (patch) | |
tree | 34690021d5688e2b9cd75982a0d1de2451f042d2 /upb/msg.h | |
parent | b0a6602fc8fddf71ac959d43b4cd82707e6235b9 (diff) | |
parent | 636b25be8d2744bc5fe41b44d36580460aa7b611 (diff) |
Merge pull request #114 from haberman/arenaonly
Enforced that upb_msg lives in an Arena only, and other simplifying.
Diffstat (limited to 'upb/msg.h')
-rw-r--r-- | upb/msg.h | 122 |
1 files changed, 15 insertions, 107 deletions
@@ -4,22 +4,17 @@ ** However it differs from other common representations like ** google::protobuf::Message in one key way: it does not prescribe any ** ownership between messages and submessages, and it relies on the -** client to delete each message/submessage/array/map at the appropriate -** time. +** client to ensure that each submessage/array/map outlives its parent. +** +** All messages, arrays, and maps live in an Arena. If the entire message +** tree is in the same arena, ensuring proper lifetimes is simple. However +** the client can mix arenas as long as they ensure that there are no +** dangling pointers. ** ** A client can access a upb::Message without knowing anything about ** ownership semantics, but to create or mutate a message a user needs ** to implement the memory management themselves. ** -** Currently all messages, arrays, and maps store a upb_alloc* internally. -** Mutating operations use this when they require dynamically-allocated -** memory. We could potentially eliminate this size overhead later by -** letting the user flip a bit on the factory that prevents this from -** being stored. The user would then need to use separate functions where -** the upb_alloc* is passed explicitly. However for handlers to populate -** such structures, they would need a place to store this upb_alloc* during -** parsing; upb_handlers don't currently have a good way to accommodate this. -** ** TODO: UTF-8 checking? **/ @@ -66,16 +61,6 @@ typedef void upb_msg; * msglayout. */ -/** upb_visitor ***************************************************************/ - -/* upb_visitor will visit all the fields of a message and its submessages. It - * uses a upb_visitorplan which you can obtain from a upb_msgfactory. */ - -upb_visitor *upb_visitor_create(upb_env *e, const upb_visitorplan *vp, - upb_sink *output); -bool upb_visitor_visitmsg(upb_visitor *v, const upb_msg *msg); - - /** upb_msgfactory ************************************************************/ /* A upb_msgfactory contains a cache of upb_msglayout, upb_handlers, and @@ -104,10 +89,6 @@ const upb_symtab *upb_msgfactory_symtab(const upb_msgfactory *f); * upb_msgfactory. */ const upb_msglayout *upb_msgfactory_getlayout(upb_msgfactory *f, const upb_msgdef *m); -const upb_handlers *upb_msgfactory_getmergehandlers(upb_msgfactory *f, - const upb_msgdef *m); -const upb_visitorplan *upb_msgfactory_getvisitorplan(upb_msgfactory *f, - const upb_handlers *h); /** upb_stringview ************************************************************/ @@ -183,52 +164,13 @@ UPB_INLINE upb_msgval upb_msgval_makestr(const char *data, size_t size) { /** upb_msg *******************************************************************/ /* A upb_msg represents a protobuf message. It always corresponds to a specific - * upb_msglayout, which describes how it is laid out in memory. - * - * The message will have a fixed size, as returned by upb_msg_sizeof(), which - * will be used to store fixed-length fields. The upb_msg may also allocate - * dynamic memory internally to store data such as: - * - * - extensions - * - unknown fields - */ + * upb_msglayout, which describes how it is laid out in memory. */ -/* Returns the size of a message given this layout. */ -size_t upb_msg_sizeof(const upb_msglayout *l); +/* Creates a new message of the given type/layout in this arena. */ +upb_msg *upb_msg_new(const upb_msglayout *l, upb_arena *a); -/* upb_msg_init() / upb_msg_uninit() allow the user to use a pre-allocated - * block of memory as a message. The block's size should be upb_msg_sizeof(). - * upb_msg_uninit() must be called to release internally-allocated memory - * unless the allocator is an arena that does not require freeing. - * - * Please note that upb_msg_init() may return a value that is different than - * |msg|, so you must assign the return value and not cast your memory block - * to upb_msg* directly! - * - * Please note that upb_msg_uninit() does *not* free any submessages, maps, - * or arrays referred to by this message's fields. You must free them manually - * yourself. - * - * upb_msg_uninit returns the original memory block, which may be useful if - * you dynamically allocated it (though upb_msg_new() would normally be more - * appropriate in this case). */ -upb_msg *upb_msg_init(void *msg, const upb_msglayout *l, upb_alloc *a); -void *upb_msg_uninit(upb_msg *msg, const upb_msglayout *l); - -/* Like upb_msg_init() / upb_msg_uninit(), except the message's memory is - * allocated / freed from the given upb_alloc. */ -upb_msg *upb_msg_new(const upb_msglayout *l, upb_alloc *a); -void upb_msg_free(upb_msg *msg, const upb_msglayout *l); - -/* Returns the upb_alloc for the given message. - * TODO(haberman): get rid of this? Not sure we want to be storing this - * for every message. */ -upb_alloc *upb_msg_alloc(const upb_msg *msg); - -/* Packs the tree of messages rooted at "msg" into a single hunk of memory, - * allocated from the given allocator. */ -void *upb_msg_pack(const upb_msg *msg, const upb_msglayout *l, - void *p, size_t *ofs, size_t size); +/* Returns the arena for the given message. */ +upb_arena *upb_msg_arena(const upb_msg *msg); /* Read-only message API. Can be safely called by anyone. */ @@ -282,16 +224,12 @@ bool upb_msg_clearfield(upb_msg *msg, * semantics are the same as upb_msg. A upb_array allocates dynamic * memory internally for the array elements. */ -size_t upb_array_sizeof(upb_fieldtype_t type); -void upb_array_init(upb_array *arr, upb_fieldtype_t type, upb_alloc *a); -void upb_array_uninit(upb_array *arr); -upb_array *upb_array_new(upb_fieldtype_t type, upb_alloc *a); -void upb_array_free(upb_array *arr); +upb_array *upb_array_new(upb_fieldtype_t type, upb_arena *a); +upb_fieldtype_t upb_array_type(const upb_array *arr); /* Read-only interface. Safe for anyone to call. */ size_t upb_array_size(const upb_array *arr); -upb_fieldtype_t upb_array_type(const upb_array *arr); upb_msgval upb_array_get(const upb_array *arr, size_t i); /* Write interface. May only be called by the message's owner who can enforce @@ -308,12 +246,8 @@ bool upb_array_set(upb_array *arr, size_t i, upb_msgval val); * So you must ensure that any string or message values outlive the map, and you * must delete them manually when they are no longer required. */ -size_t upb_map_sizeof(upb_fieldtype_t ktype, upb_fieldtype_t vtype); -bool upb_map_init(upb_map *map, upb_fieldtype_t ktype, upb_fieldtype_t vtype, - upb_alloc *a); -void upb_map_uninit(upb_map *map); -upb_map *upb_map_new(upb_fieldtype_t ktype, upb_fieldtype_t vtype, upb_alloc *a); -void upb_map_free(upb_map *map); +upb_map *upb_map_new(upb_fieldtype_t ktype, upb_fieldtype_t vtype, + upb_arena *a); /* Read-only interface. Safe for anyone to call. */ @@ -358,32 +292,6 @@ void upb_mapiter_setdone(upb_mapiter *i); bool upb_mapiter_isequal(const upb_mapiter *i1, const upb_mapiter *i2); -/** Handlers ******************************************************************/ - -/* These are the handlers used internally by upb_msgfactory_getmergehandlers(). - * They write scalar data to a known offset from the message pointer. - * - * These would be trivial for anyone to implement themselves, but it's better - * to use these because some JITs will recognize and specialize these instead - * of actually calling the function. */ - -/* Sets a handler for the given primitive field that will write the data at the - * given offset. If hasbit > 0, also sets a hasbit at the given bit offset - * (addressing each byte low to high). */ -bool upb_msg_setscalarhandler(upb_handlers *h, - const upb_fielddef *f, - size_t offset, - int32_t hasbit); - -/* If the given handler is a msghandlers_primitive field, returns true and sets - * *type, *offset and *hasbit. Otherwise returns false. */ -bool upb_msg_getscalarhandlerdata(const upb_handlers *h, - upb_selector_t s, - upb_fieldtype_t *type, - size_t *offset, - int32_t *hasbit); - - /** Interfaces for generated code *********************************************/ #define UPB_NOT_IN_ONEOF UINT16_MAX |