From b471ca6b81b88dc23aae6a53345d94d9a2714a7c Mon Sep 17 00:00:00 2001 From: Joshua Haberman Date: Mon, 6 Dec 2010 15:52:40 -0800 Subject: The last major revision to the upb_stream protocol. Sources and sinks communicate by means of a upb_handlers object, which encapsulates a set of handler callbacks and will possibly offer richer semantics in the future like giving specific fields different callbacks. The upb_handlers protocol supports delegation, so sets of handlers can be written in reusable ways. For example, if a set of handlers is written to handle a specific .proto type, those handlers can be used whether that type is at the top level or whether it is a sub-message of a higher-level type. Delegation allows the streaming protocol to properly compose. --- core/upb_stream_vtbl.h | 235 +++++++++++++++++++++---------------------------- 1 file changed, 100 insertions(+), 135 deletions(-) (limited to 'core/upb_stream_vtbl.h') diff --git a/core/upb_stream_vtbl.h b/core/upb_stream_vtbl.h index 96f6cfe..91464a7 100644 --- a/core/upb_stream_vtbl.h +++ b/core/upb_stream_vtbl.h @@ -5,59 +5,21 @@ * interfaces. Only components that are implementing these interfaces need * to worry about this file. * - * This is tedious; this is the place in upb where I most wish I had a C++ - * feature. In C++ the compiler would generate this all for me. If there's - * any consolation, it's that I have a bit of flexibility you don't have in - * C++: I could, with preprocessor magic alone "de-virtualize" this interface - * for a particular source file. Say I had a C file that called a upb_src, - * but didn't want to pay the virtual function overhead. I could define: - * - * #define upb_src_getdef(src) upb_decoder_getdef((upb_decoder*)src) - * #define upb_src_stargmsg(src) upb_decoder_startmsg(upb_decoder*)src) - * // etc. - * - * The source file is compatible with the regular upb_src interface, but here - * we bind it to a particular upb_src (upb_decoder), which could lead to - * improved performance at a loss of flexibility for this one upb_src client. - * * Copyright (c) 2010 Joshua Haberman. See LICENSE for details. */ #ifndef UPB_SRCSINK_VTBL_H_ #define UPB_SRCSINK_VTBL_H_ -#include "upb.h" +#include +#include "upb_stream.h" #ifdef __cplusplus extern "C" { #endif -struct upb_src; -typedef struct upb_src upb_src; -struct upb_sink; -typedef struct upb_sink upb_sink; -struct upb_bytesrc; -typedef struct upb_bytesrc upb_bytesrc; -struct upb_bytesink; -typedef struct upb_bytesink upb_bytesink; - // Typedefs for function pointers to all of the virtual functions. -// upb_src. -typedef struct _upb_fielddef *(*upb_src_getdef_fptr)(upb_src *src); -typedef bool (*upb_src_getval_fptr)(upb_src *src, upb_valueptr val); -typedef bool (*upb_src_getstr_fptr)(upb_src *src, upb_string *str); -typedef bool (*upb_src_skipval_fptr)(upb_src *src); -typedef bool (*upb_src_startmsg_fptr)(upb_src *src); -typedef bool (*upb_src_endmsg_fptr)(upb_src *src); - -// upb_sink. -typedef bool (*upb_sink_putdef_fptr)(upb_sink *sink, struct _upb_fielddef *def); -typedef bool (*upb_sink_putval_fptr)(upb_sink *sink, upb_value val); -typedef bool (*upb_sink_putstr_fptr)(upb_sink *sink, upb_string *str); -typedef bool (*upb_sink_startmsg_fptr)(upb_sink *sink); -typedef bool (*upb_sink_endmsg_fptr)(upb_sink *sink); - // upb_bytesrc. typedef bool (*upb_bytesrc_get_fptr)( upb_bytesrc *src, upb_string *str, upb_strlen_t minlen); @@ -68,23 +30,6 @@ typedef bool (*upb_bytesrc_append_fptr)( typedef int32_t (*upb_bytesink_put_fptr)(upb_bytesink *sink, upb_string *str); // Vtables for the above interfaces. -typedef struct { - upb_src_getdef_fptr getdef; - upb_src_getval_fptr getval; - upb_src_getstr_fptr getstr; - upb_src_skipval_fptr skipval; - upb_src_startmsg_fptr startmsg; - upb_src_endmsg_fptr endmsg; -} upb_src_vtable; - -typedef struct { - upb_sink_putdef_fptr putdef; - upb_sink_putval_fptr putval; - upb_sink_putstr_fptr putstr; - upb_sink_startmsg_fptr startmsg; - upb_sink_endmsg_fptr endmsg; -} upb_sink_vtable; - typedef struct { upb_bytesrc_get_fptr get; upb_bytesrc_append_fptr append; @@ -97,42 +42,18 @@ typedef struct { // "Base Class" definitions; components that implement these interfaces should // contain one of these structures. -struct upb_src { - upb_src_vtable *vtbl; - upb_status status; - bool eof; -}; - -struct upb_sink { - upb_sink_vtable *vtbl; - upb_status status; - bool eof; -}; - -struct upb_bytesrc { +struct _upb_bytesrc { upb_bytesrc_vtable *vtbl; upb_status status; bool eof; }; -struct upb_bytesink { +struct _upb_bytesink { upb_bytesink_vtable *vtbl; upb_status status; bool eof; }; -INLINE void upb_src_init(upb_src *s, upb_src_vtable *vtbl) { - s->vtbl = vtbl; - s->eof = false; - upb_status_init(&s->status); -} - -INLINE void upb_sink_init(upb_sink *s, upb_sink_vtable *vtbl) { - s->vtbl = vtbl; - s->eof = false; - upb_status_init(&s->status); -} - INLINE void upb_bytesrc_init(upb_bytesrc *s, upb_bytesrc_vtable *vtbl) { s->vtbl = vtbl; s->eof = false; @@ -146,46 +67,6 @@ INLINE void upb_bytesink_init(upb_bytesink *s, upb_bytesink_vtable *vtbl) { } // Implementation of virtual function dispatch. -INLINE struct _upb_fielddef *upb_src_getdef(upb_src *src) { - return src->vtbl->getdef(src); -} -INLINE bool upb_src_getval(upb_src *src, upb_valueptr val) { - return src->vtbl->getval(src, val); -} -INLINE bool upb_src_getstr(upb_src *src, upb_string *str) { - return src->vtbl->getstr(src, str); -} -INLINE bool upb_src_skipval(upb_src *src) { return src->vtbl->skipval(src); } -INLINE bool upb_src_startmsg(upb_src *src) { return src->vtbl->startmsg(src); } -INLINE bool upb_src_endmsg(upb_src *src) { return src->vtbl->endmsg(src); } - -// Implementation of type-specific upb_src accessors. If we encounter a upb_src -// where these can be implemented directly in a measurably more efficient way, -// we can make these part of the vtable also. -// -// For <64-bit types we have to use a temporary to accommodate baredecoder, -// which does not know the actual width of the type. -INLINE bool upb_src_getbool(upb_src *src, bool *_bool) { - upb_value val; - bool ret = upb_src_getval(src, upb_value_addrof(&val)); - *_bool = val._bool; - return ret; -} - -INLINE bool upb_src_getint32(upb_src *src, int32_t *i32) { - upb_value val; - bool ret = upb_src_getval(src, upb_value_addrof(&val)); - *i32 = val.int32; - return ret; -} - -// TODO. -bool upb_src_getint32(upb_src *src, int32_t *val); -bool upb_src_getint64(upb_src *src, int64_t *val); -bool upb_src_getuint32(upb_src *src, uint32_t *val); -bool upb_src_getuint64(upb_src *src, uint64_t *val); -bool upb_src_getfloat(upb_src *src, float *val); -bool upb_src_getdouble(upb_src *src, double *val); // upb_bytesrc INLINE bool upb_bytesrc_get( @@ -198,24 +79,108 @@ INLINE bool upb_bytesrc_append( return bytesrc->vtbl->append(bytesrc, str, len); } -// upb_sink -INLINE bool upb_sink_putdef(upb_sink *sink, struct _upb_fielddef *def) { - return sink->vtbl->putdef(sink, def); +INLINE upb_status *upb_bytesrc_status(upb_bytesrc *src) { return &src->status; } +INLINE bool upb_bytesrc_eof(upb_bytesrc *src) { return src->eof; } + +// upb_handlers +struct _upb_handlers { + upb_handlerset *set; + void *closure; +}; + +INLINE void upb_handlers_init(upb_handlers *h) { + (void)h; +} +INLINE void upb_handlers_uninit(upb_handlers *h) { + (void)h; +} + +INLINE void upb_handlers_reset(upb_handlers *h) { + h->set = NULL; + h->closure = NULL; +} + +INLINE bool upb_handlers_isempty(upb_handlers *h) { + return !h->set && !h->closure; +} + +INLINE void upb_register_handlerset(upb_handlers *h, upb_handlerset *set) { + h->set = set; +} + +INLINE void upb_set_handler_closure(upb_handlers *h, void *closure) { + h->closure = closure; +} + +// upb_dispatcher +typedef struct { + upb_handlers handlers; + int depth; +} upb_dispatcher_frame; + +struct _upb_dispatcher { + upb_dispatcher_frame stack[UPB_MAX_NESTING], *top, *limit; +}; + +INLINE void upb_dispatcher_init(upb_dispatcher *d) { + d->limit = d->stack + sizeof(d->stack); } -INLINE bool upb_sink_putval(upb_sink *sink, upb_value val) { - return sink->vtbl->putval(sink, val); + +INLINE void upb_dispatcher_reset(upb_dispatcher *d, upb_handlers *h) { + d->top = d->stack; + d->top->depth = 1; // Never want to trigger end-of-delegation. + d->top->handlers = *h; } -INLINE bool upb_sink_putstr(upb_sink *sink, upb_string *str) { - return sink->vtbl->putstr(sink, str); + +INLINE void upb_dispatch_startmsg(upb_dispatcher *d) { + assert(d->stack == d->top); + d->top->handlers.set->startmsg(d->top->handlers.closure); } -INLINE bool upb_sink_startmsg(upb_sink *sink) { - return sink->vtbl->startmsg(sink); + +INLINE void upb_dispatch_endmsg(upb_dispatcher *d) { + assert(d->stack == d->top); + d->top->handlers.set->endmsg(d->top->handlers.closure); } -INLINE bool upb_sink_endmsg(upb_sink *sink) { - return sink->vtbl->endmsg(sink); + +INLINE upb_flow_t upb_dispatch_startsubmsg(upb_dispatcher *d, + struct _upb_fielddef *f) { + upb_handlers handlers; + upb_handlers_init(&handlers); + upb_handlers_reset(&handlers); + upb_flow_t ret = d->top->handlers.set->startsubmsg(d->top->handlers.closure, f, &handlers); + assert((ret == UPB_DELEGATE) == !upb_handlers_isempty(&handlers)); + if (ret == UPB_DELEGATE) { + ++d->top; + d->top->handlers = handlers; + d->top->depth = 0; + d->top->handlers.set->startmsg(d->top->handlers.closure); + ret = UPB_CONTINUE; + } + ++d->top->depth; + upb_handlers_uninit(&handlers); + return ret; +} + +INLINE upb_flow_t upb_dispatch_endsubmsg(upb_dispatcher *d) { + if (--d->top->depth == 0) { + d->top->handlers.set->endmsg(d->top->handlers.closure); + --d->top; + } + return d->top->handlers.set->endsubmsg(d->top->handlers.closure); } -INLINE upb_status *upb_sink_status(upb_sink *sink) { return &sink->status; } +INLINE upb_flow_t upb_dispatch_value(upb_dispatcher *d, + struct _upb_fielddef *f, + upb_value val) { + return d->top->handlers.set->value(d->top->handlers.closure, f, val); +} + +INLINE upb_flow_t upb_dispatch_unknownval(upb_dispatcher *d, + upb_field_number_t fieldnum, + upb_value val) { + return d->top->handlers.set->unknownval(d->top->handlers.closure, + fieldnum, val); +} // upb_bytesink INLINE int32_t upb_bytesink_put(upb_bytesink *sink, upb_string *str) { -- cgit v1.2.3