From c850bc0a4e62c1c9c21c1f6cfe3b8293e64831cf Mon Sep 17 00:00:00 2001 From: Josh Haberman Date: Sat, 21 Jan 2017 10:04:59 -0800 Subject: Moved upb_symtab to def.h/def.c. This is in anticipation of removing refcounting and making upb_symtab (soon to be upb_defpool) the unique owner of all defs inside. --- upb/def.h | 173 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 173 insertions(+) (limited to 'upb/def.h') diff --git a/upb/def.h b/upb/def.h index 724a85c..b2c42a6 100644 --- a/upb/def.h +++ b/upb/def.h @@ -35,6 +35,7 @@ class FieldDef; class FileDef; class MessageDef; class OneofDef; +class SymbolTable; } #endif @@ -43,6 +44,9 @@ UPB_DECLARE_DERIVED_TYPE(upb::OneofDef, upb::RefCounted, upb_oneofdef, upb_refcounted) UPB_DECLARE_DERIVED_TYPE(upb::FileDef, upb::RefCounted, upb_filedef, upb_refcounted) +UPB_DECLARE_DERIVED_TYPE(upb::SymbolTable, upb::RefCounted, + upb_symtab, upb_refcounted) + /* The maximum message depth that the type graph can have. This is a resource * limit for the C stack since we sometimes need to recursively traverse the @@ -1417,6 +1421,175 @@ UPB_INLINE upb_def *upb_filedef_mutabledef(upb_filedef *f, int i) { UPB_END_EXTERN_C +typedef struct { + UPB_PRIVATE_FOR_CPP + upb_strtable_iter iter; + upb_deftype_t type; +} upb_symtab_iter; + +#ifdef __cplusplus + +/* Non-const methods in upb::SymbolTable are NOT thread-safe. */ +class upb::SymbolTable { + public: + /* Returns a new symbol table with a single ref owned by "owner." + * Returns NULL if memory allocation failed. */ + static reffed_ptr New(); + + /* Include RefCounted base methods. */ + UPB_REFCOUNTED_CPPMETHODS + + /* For all lookup functions, the returned pointer is not owned by the + * caller; it may be invalidated by any non-const call or unref of the + * SymbolTable! To protect against this, take a ref if desired. */ + + /* Freezes the symbol table: prevents further modification of it. + * After the Freeze() operation is successful, the SymbolTable must only be + * accessed via a const pointer. + * + * Unlike with upb::MessageDef/upb::EnumDef/etc, freezing a SymbolTable is not + * a necessary step in using a SymbolTable. If you have no need for it to be + * immutable, there is no need to freeze it ever. However sometimes it is + * useful, and SymbolTables that are statically compiled into the binary are + * always frozen by nature. */ + void Freeze(); + + /* Resolves the given symbol using the rules described in descriptor.proto, + * namely: + * + * If the name starts with a '.', it is fully-qualified. Otherwise, + * C++-like scoping rules are used to find the type (i.e. first the nested + * types within this message are searched, then within the parent, on up + * to the root namespace). + * + * If not found, returns NULL. */ + const Def* Resolve(const char* base, const char* sym) const; + + /* Finds an entry in the symbol table with this exact name. If not found, + * returns NULL. */ + const Def* Lookup(const char *sym) const; + const MessageDef* LookupMessage(const char *sym) const; + const EnumDef* LookupEnum(const char *sym) const; + + /* TODO: introduce a C++ iterator, but make it nice and templated so that if + * you ask for an iterator of MessageDef the iterated elements are strongly + * typed as MessageDef*. */ + + /* Adds the given mutable defs to the symtab, resolving all symbols + * (including enum default values) and finalizing the defs. Only one def per + * name may be in the list, but defs can replace existing defs in the symtab. + * All defs must have a name -- anonymous defs are not allowed. Anonymous + * defs can still be frozen by calling upb_def_freeze() directly. + * + * Any existing defs that can reach defs that are being replaced will + * themselves be replaced also, so that the resulting set of defs is fully + * consistent. + * + * This logic implemented in this method is a convenience; ultimately it + * calls some combination of upb_fielddef_setsubdef(), upb_def_dup(), and + * upb_freeze(), any of which the client could call themself. However, since + * the logic for doing so is nontrivial, we provide it here. + * + * The entire operation either succeeds or fails. If the operation fails, + * the symtab is unchanged, false is returned, and status indicates the + * error. The caller passes a ref on all defs to the symtab (even if the + * operation fails). + * + * TODO(haberman): currently failure will leave the symtab unchanged, but may + * leave the defs themselves partially resolved. Does this matter? If so we + * could do a prepass that ensures that all symbols are resolvable and bail + * if not, so we don't mutate anything until we know the operation will + * succeed. + * + * TODO(haberman): since the defs must be mutable, refining a frozen def + * requires making mutable copies of the entire tree. This is wasteful if + * only a few messages are changing. We may want to add a way of adding a + * tree of frozen defs to the symtab (perhaps an alternate constructor where + * you pass the root of the tree?) */ + bool Add(Def*const* defs, size_t n, void* ref_donor, Status* status); + + bool Add(const std::vector& defs, void *owner, Status* status) { + return Add((Def*const*)&defs[0], defs.size(), owner, status); + } + + /* Resolves all subdefs for messages in this file and attempts to freeze the + * file. If this succeeds, adds all the symbols to this SymbolTable + * (replacing any existing ones with the same names). */ + bool AddFile(FileDef* file, Status* s); + + private: + UPB_DISALLOW_POD_OPS(SymbolTable, upb::SymbolTable) +}; + +#endif /* __cplusplus */ + +UPB_BEGIN_EXTERN_C + +/* Native C API. */ + +/* Include refcounted methods like upb_symtab_ref(). */ +UPB_REFCOUNTED_CMETHODS(upb_symtab, upb_symtab_upcast) + +upb_symtab *upb_symtab_new(const void *owner); +void upb_symtab_freeze(upb_symtab *s); +const upb_def *upb_symtab_resolve(const upb_symtab *s, const char *base, + const char *sym); +const upb_def *upb_symtab_lookup(const upb_symtab *s, const char *sym); +const upb_msgdef *upb_symtab_lookupmsg(const upb_symtab *s, const char *sym); +const upb_enumdef *upb_symtab_lookupenum(const upb_symtab *s, const char *sym); +bool upb_symtab_add(upb_symtab *s, upb_def *const*defs, size_t n, + void *ref_donor, upb_status *status); +bool upb_symtab_addfile(upb_symtab *s, upb_filedef *file, upb_status* status); + +/* upb_symtab_iter i; + * for(upb_symtab_begin(&i, s, type); !upb_symtab_done(&i); + * upb_symtab_next(&i)) { + * const upb_def *def = upb_symtab_iter_def(&i); + * // ... + * } + * + * For C we don't have separate iterators for const and non-const. + * It is the caller's responsibility to cast the upb_fielddef* to + * const if the upb_msgdef* is const. */ +void upb_symtab_begin(upb_symtab_iter *iter, const upb_symtab *s, + upb_deftype_t type); +void upb_symtab_next(upb_symtab_iter *iter); +bool upb_symtab_done(const upb_symtab_iter *iter); +const upb_def *upb_symtab_iter_def(const upb_symtab_iter *iter); + +UPB_END_EXTERN_C + +#ifdef __cplusplus +/* C++ inline wrappers. */ +namespace upb { +inline reffed_ptr SymbolTable::New() { + upb_symtab *s = upb_symtab_new(&s); + return reffed_ptr(s, &s); +} + +inline void SymbolTable::Freeze() { + return upb_symtab_freeze(this); +} +inline const Def *SymbolTable::Resolve(const char *base, + const char *sym) const { + return upb_symtab_resolve(this, base, sym); +} +inline const Def* SymbolTable::Lookup(const char *sym) const { + return upb_symtab_lookup(this, sym); +} +inline const MessageDef *SymbolTable::LookupMessage(const char *sym) const { + return upb_symtab_lookupmsg(this, sym); +} +inline bool SymbolTable::Add( + Def*const* defs, size_t n, void* ref_donor, Status* status) { + return upb_symtab_add(this, (upb_def*const*)defs, n, ref_donor, status); +} +inline bool SymbolTable::AddFile(FileDef* file, Status* s) { + return upb_symtab_addfile(this, file, s); +} +} /* namespace upb */ +#endif + #ifdef __cplusplus UPB_INLINE const char* upb_safecstr(const std::string& str) { -- cgit v1.2.3