diff options
Diffstat (limited to 'upb/pb/encoder.c')
| -rw-r--r-- | upb/pb/encoder.c | 199 |
1 files changed, 103 insertions, 96 deletions
diff --git a/upb/pb/encoder.c b/upb/pb/encoder.c index ca5ebc1..e704bbd 100644 --- a/upb/pb/encoder.c +++ b/upb/pb/encoder.c @@ -62,73 +62,74 @@ #include <stdlib.h> -// The output buffer is divided into segments; a segment is a string of data -// that is "ready to go" -- it does not need any varint lengths inserted into -// the middle. The seams between segments are where varints will be inserted -// once they are known. -// -// We also use the concept of a "run", which is a range of encoded bytes that -// occur at a single submessage level. Every segment contains one or more runs. -// -// A segment can span messages. Consider: -// -// .--Submessage lengths---------. -// | | | -// | V V -// V | |--------------- | |----------------- -// Submessages: | |----------------------------------------------- -// Top-level msg: ------------------------------------------------------------ -// -// Segments: ----- ------------------- ----------------- -// Runs: *---- *--------------*--- *---------------- -// (* marks the start) -// -// Note that the top-level menssage is not in any segment because it does not -// have any length preceding it. -// -// A segment is only interrupted when another length needs to be inserted. So -// observe how the second segment spans both the inner submessage and part of -// the next enclosing message. +/* The output buffer is divided into segments; a segment is a string of data + * that is "ready to go" -- it does not need any varint lengths inserted into + * the middle. The seams between segments are where varints will be inserted + * once they are known. + * + * We also use the concept of a "run", which is a range of encoded bytes that + * occur at a single submessage level. Every segment contains one or more runs. + * + * A segment can span messages. Consider: + * + * .--Submessage lengths---------. + * | | | + * | V V + * V | |--------------- | |----------------- + * Submessages: | |----------------------------------------------- + * Top-level msg: ------------------------------------------------------------ + * + * Segments: ----- ------------------- ----------------- + * Runs: *---- *--------------*--- *---------------- + * (* marks the start) + * + * Note that the top-level menssage is not in any segment because it does not + * have any length preceding it. + * + * A segment is only interrupted when another length needs to be inserted. So + * observe how the second segment spans both the inner submessage and part of + * the next enclosing message. */ typedef struct { - uint32_t msglen; // The length to varint-encode before this segment. - uint32_t seglen; // Length of the segment. + uint32_t msglen; /* The length to varint-encode before this segment. */ + uint32_t seglen; /* Length of the segment. */ } upb_pb_encoder_segment; struct upb_pb_encoder { upb_env *env; - // Our input and output. + /* Our input and output. */ upb_sink input_; upb_bytessink *output_; - // The "subclosure" -- used as the inner closure as part of the bytessink - // protocol. + /* The "subclosure" -- used as the inner closure as part of the bytessink + * protocol. */ void *subc; - // The output buffer and limit, and our current write position. "buf" - // initially points to "initbuf", but is dynamically allocated if we need to - // grow beyond the initial size. + /* The output buffer and limit, and our current write position. "buf" + * initially points to "initbuf", but is dynamically allocated if we need to + * grow beyond the initial size. */ char *buf, *ptr, *limit; - // The beginning of the current run, or undefined if we are at the top level. + /* The beginning of the current run, or undefined if we are at the top + * level. */ char *runbegin; - // The list of segments we are accumulating. + /* The list of segments we are accumulating. */ upb_pb_encoder_segment *segbuf, *segptr, *seglimit; - // The stack of enclosing submessages. Each entry in the stack points to the - // segment where this submessage's length is being accumulated. + /* The stack of enclosing submessages. Each entry in the stack points to the + * segment where this submessage's length is being accumulated. */ int *stack, *top, *stacklimit; - // Depth of startmsg/endmsg calls. + /* Depth of startmsg/endmsg calls. */ int depth; }; /* low-level buffering ********************************************************/ -// Low-level functions for interacting with the output buffer. +/* Low-level functions for interacting with the output buffer. */ -// TODO(haberman): handle pushback +/* TODO(haberman): handle pushback */ static void putbuf(upb_pb_encoder *e, const char *buf, size_t len) { size_t n = upb_bytessink_putbuf(e->output_, e->subc, buf, len, NULL); UPB_ASSERT_VAR(n, n == len); @@ -138,11 +139,12 @@ static upb_pb_encoder_segment *top(upb_pb_encoder *e) { return &e->segbuf[*e->top]; } -// Call to ensure that at least "bytes" bytes are available for writing at -// e->ptr. Returns false if the bytes could not be allocated. +/* Call to ensure that at least "bytes" bytes are available for writing at + * e->ptr. Returns false if the bytes could not be allocated. */ static bool reserve(upb_pb_encoder *e, size_t bytes) { if ((size_t)(e->limit - e->ptr) < bytes) { - // Grow buffer. + /* Grow buffer. */ + char *new_buf; size_t needed = bytes + (e->ptr - e->buf); size_t old_size = e->limit - e->buf; @@ -152,7 +154,7 @@ static bool reserve(upb_pb_encoder *e, size_t bytes) { new_size *= 2; } - char *new_buf = upb_env_realloc(e->env, e->buf, old_size, new_size); + new_buf = upb_env_realloc(e->env, e->buf, old_size, new_size); if (new_buf == NULL) { return false; @@ -167,22 +169,22 @@ static bool reserve(upb_pb_encoder *e, size_t bytes) { return true; } -// Call when "bytes" bytes have been writte at e->ptr. The caller *must* have -// previously called reserve() with at least this many bytes. +/* Call when "bytes" bytes have been writte at e->ptr. The caller *must* have + * previously called reserve() with at least this many bytes. */ static void encoder_advance(upb_pb_encoder *e, size_t bytes) { assert((size_t)(e->limit - e->ptr) >= bytes); e->ptr += bytes; } -// Call when all of the bytes for a handler have been written. Flushes the -// bytes if possible and necessary, returning false if this failed. +/* Call when all of the bytes for a handler have been written. Flushes the + * bytes if possible and necessary, returning false if this failed. */ static bool commit(upb_pb_encoder *e) { if (!e->top) { - // We aren't inside a delimited region. Flush our accumulated bytes to - // the output. - // - // TODO(haberman): in the future we may want to delay flushing for - // efficiency reasons. + /* We aren't inside a delimited region. Flush our accumulated bytes to + * the output. + * + * TODO(haberman): in the future we may want to delay flushing for + * efficiency reasons. */ putbuf(e, e->buf, e->ptr - e->buf); e->ptr = e->buf; } @@ -190,7 +192,7 @@ static bool commit(upb_pb_encoder *e) { return true; } -// Writes the given bytes to the buffer, handling reserve/advance. +/* Writes the given bytes to the buffer, handling reserve/advance. */ static bool encode_bytes(upb_pb_encoder *e, const void *data, size_t len) { if (!reserve(e, len)) { return false; @@ -201,32 +203,33 @@ static bool encode_bytes(upb_pb_encoder *e, const void *data, size_t len) { return true; } -// Finish the current run by adding the run totals to the segment and message -// length. +/* Finish the current run by adding the run totals to the segment and message + * length. */ static void accumulate(upb_pb_encoder *e) { + size_t run_len; assert(e->ptr >= e->runbegin); - size_t run_len = e->ptr - e->runbegin; + run_len = e->ptr - e->runbegin; e->segptr->seglen += run_len; top(e)->msglen += run_len; e->runbegin = e->ptr; } -// Call to indicate the start of delimited region for which the full length is -// not yet known. All data will be buffered until the length is known. -// Delimited regions may be nested; their lengths will all be tracked properly. +/* Call to indicate the start of delimited region for which the full length is + * not yet known. All data will be buffered until the length is known. + * Delimited regions may be nested; their lengths will all be tracked properly. */ static bool start_delim(upb_pb_encoder *e) { if (e->top) { - // We are already buffering, advance to the next segment and push it on the - // stack. + /* We are already buffering, advance to the next segment and push it on the + * stack. */ accumulate(e); if (++e->top == e->stacklimit) { - // TODO(haberman): grow stack? + /* TODO(haberman): grow stack? */ return false; } if (++e->segptr == e->seglimit) { - // Grow segment buffer. + /* Grow segment buffer. */ size_t old_size = (e->seglimit - e->segbuf) * sizeof(upb_pb_encoder_segment); size_t new_size = old_size * 2; @@ -242,7 +245,7 @@ static bool start_delim(upb_pb_encoder *e) { e->segbuf = new_buf; } } else { - // We were previously at the top level, start buffering. + /* We were previously at the top level, start buffering. */ e->segptr = e->segbuf; e->top = e->stack; e->runbegin = e->ptr; @@ -255,15 +258,16 @@ static bool start_delim(upb_pb_encoder *e) { return true; } -// Call to indicate the end of a delimited region. We now know the length of -// the delimited region. If we are not nested inside any other delimited -// regions, we can now emit all of the buffered data we accumulated. +/* Call to indicate the end of a delimited region. We now know the length of + * the delimited region. If we are not nested inside any other delimited + * regions, we can now emit all of the buffered data we accumulated. */ static bool end_delim(upb_pb_encoder *e) { + size_t msglen; accumulate(e); - size_t msglen = top(e)->msglen; + msglen = top(e)->msglen; if (e->top == e->stack) { - // All lengths are now available, emit all buffered data. + /* All lengths are now available, emit all buffered data. */ char buf[UPB_PB_VARINT_MAX_LEN]; upb_pb_encoder_segment *s; const char *ptr = e->buf; @@ -277,7 +281,8 @@ static bool end_delim(upb_pb_encoder *e) { e->ptr = e->buf; e->top = NULL; } else { - // Need to keep buffering; propagate length info into enclosing submessages. + /* Need to keep buffering; propagate length info into enclosing + * submessages. */ --e->top; top(e)->msglen += msglen + upb_varint_size(msglen); } @@ -288,14 +293,14 @@ static bool end_delim(upb_pb_encoder *e) { /* tag_t **********************************************************************/ -// A precomputed (pre-encoded) tag and length. +/* A precomputed (pre-encoded) tag and length. */ typedef struct { uint8_t bytes; char tag[7]; } tag_t; -// Allocates a new tag for this field, and sets it in these handlerattr. +/* Allocates a new tag for this field, and sets it in these handlerattr. */ static void new_tag(upb_handlers *h, const upb_fielddef *f, upb_wiretype_t wt, upb_handlerattr *attr) { uint32_t n = upb_fielddef_number(f); @@ -316,12 +321,12 @@ static bool encode_tag(upb_pb_encoder *e, const tag_t *tag) { /* encoding of wire types *****************************************************/ static bool encode_fixed64(upb_pb_encoder *e, uint64_t val) { - // TODO(haberman): byte-swap for big endian. + /* TODO(haberman): byte-swap for big endian. */ return encode_bytes(e, &val, sizeof(uint64_t)); } static bool encode_fixed32(upb_pb_encoder *e, uint32_t val) { - // TODO(haberman): byte-swap for big endian. + /* TODO(haberman): byte-swap for big endian. */ return encode_bytes(e, &val, sizeof(uint32_t)); } @@ -408,19 +413,19 @@ static size_t encode_strbuf(void *c, const void *hd, const char *buf, } T(double, double, dbl2uint64, encode_fixed64) -T(float, float, flt2uint32, encode_fixed32); -T(int64, int64_t, uint64_t, encode_varint); -T(int32, int32_t, uint32_t, encode_varint); -T(fixed64, uint64_t, uint64_t, encode_fixed64); -T(fixed32, uint32_t, uint32_t, encode_fixed32); -T(bool, bool, bool, encode_varint); -T(uint32, uint32_t, uint32_t, encode_varint); -T(uint64, uint64_t, uint64_t, encode_varint); -T(enum, int32_t, uint32_t, encode_varint); -T(sfixed32, int32_t, uint32_t, encode_fixed32); -T(sfixed64, int64_t, uint64_t, encode_fixed64); -T(sint32, int32_t, upb_zzenc_32, encode_varint); -T(sint64, int64_t, upb_zzenc_64, encode_varint); +T(float, float, flt2uint32, encode_fixed32) +T(int64, int64_t, uint64_t, encode_varint) +T(int32, int32_t, uint32_t, encode_varint) +T(fixed64, uint64_t, uint64_t, encode_fixed64) +T(fixed32, uint32_t, uint32_t, encode_fixed32) +T(bool, bool, bool, encode_varint) +T(uint32, uint32_t, uint32_t, encode_varint) +T(uint64, uint64_t, uint64_t, encode_varint) +T(enum, int32_t, uint32_t, encode_varint) +T(sfixed32, int32_t, uint32_t, encode_fixed32) +T(sfixed64, int64_t, uint64_t, encode_fixed64) +T(sint32, int32_t, upb_zzenc_32, encode_varint) +T(sint64, int64_t, upb_zzenc_64, encode_varint) #undef T @@ -428,13 +433,15 @@ T(sint64, int64_t, upb_zzenc_64, encode_varint); /* code to build the handlers *************************************************/ static void newhandlers_callback(const void *closure, upb_handlers *h) { + const upb_msgdef *m; + upb_msg_field_iter i; + UPB_UNUSED(closure); upb_handlers_setstartmsg(h, startmsg, NULL); upb_handlers_setendmsg(h, endmsg, NULL); - const upb_msgdef *m = upb_handlers_msgdef(h); - upb_msg_field_iter i; + m = upb_handlers_msgdef(h); for(upb_msg_field_begin(&i, m); !upb_msg_field_done(&i); upb_msg_field_next(&i)) { @@ -446,7 +453,7 @@ static void newhandlers_callback(const void *closure, upb_handlers *h) { packed ? UPB_WIRE_TYPE_DELIMITED : upb_pb_native_wire_types[upb_fielddef_descriptortype(f)]; - // Pre-encode the tag for this field. + /* Pre-encode the tag for this field. */ new_tag(h, f, wt, &attr); if (packed) { @@ -489,7 +496,7 @@ static void newhandlers_callback(const void *closure, upb_handlers *h) { upb_handlers_setendsubmsg(h, f, encode_enddelimfield, &attr); break; case UPB_DESCRIPTOR_TYPE_GROUP: { - // Endgroup takes a different tag (wire_type = END_GROUP). + /* Endgroup takes a different tag (wire_type = END_GROUP). */ upb_handlerattr attr2; new_tag(h, f, UPB_WIRE_TYPE_END_GROUP, &attr2); @@ -525,7 +532,7 @@ upb_pb_encoder *upb_pb_encoder_create(upb_env *env, const upb_handlers *h, upb_bytessink *output) { const size_t initial_bufsize = 256; const size_t initial_segbufsize = 16; - // TODO(haberman): make this configurable. + /* TODO(haberman): make this configurable. */ const size_t stack_size = 64; #ifndef NDEBUG const size_t size_before = upb_env_bytesallocated(env); @@ -554,7 +561,7 @@ upb_pb_encoder *upb_pb_encoder_create(upb_env *env, const upb_handlers *h, e->subc = output->closure; e->ptr = e->buf; - // If this fails, increase the value in encoder.h. + /* If this fails, increase the value in encoder.h. */ assert(upb_env_bytesallocated(env) - size_before <= UPB_PB_ENCODER_SIZE); return e; } |