Chiebot-Mirror
/
protobuf
mirror of https://github.com/protocolbuffers/protobuf.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

Work on decoder buffering.

Browse Source
pull/13171/head
Joshua Haberman 15 years ago
parent d7e631d9b0
commit edd1f5a61f
2 changed files with 85 additions and 68 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 148
      src/upb_decoder.c
  2. 5
      src/upb_srcsink.h

148
src/upb_decoder.c
Unescape View File

@ -42,19 +42,21 @@ struct upb_decoder {
// We keep a stack of messages we have recursed into.
upb_decoder_frame stack[UPB_MAX_NESTING], *top, *limit;
// The buffers of input data. See buffering code below for details.
// The buffer of input data. NULL is equivalent to the empty string.
upb_string *buf;
upb_string *nextbuf;
uint8_t tmpbuf[UPB_MAX_ENCODED_SIZE]; // Used to bridge buf and nextbuf.
// Holds residual bytes when fewer than UPB_MAX_ENCODED_SIZE bytes remain.
uint8_t tmpbuf[UPB_MAX_ENCODED_SIZE];
// The number of bytes we have yet to consume from "buf". This can be
// negative if we have skipped more bytes than are in the buffer, or if we
// have started to consume bytes from "nextbuf".
int32_t buf_bytesleft;
int32_t buf_offset;
// The overall stream offset of the end of "buf". If "buf" is NULL, it is as
// if "buf" was the empty string.
uint32_t buf_endoffset;
uint32_t buf_stream_offset;
// Fielddef for the key we just read.
upb_fielddef *field;
@ -76,29 +78,39 @@ struct upb_decoder {
static upb_strlen_t upb_decoder_offset(upb_decoder *d)
{
return d->buf_endoffset - d->buf_bytesleft;
return d->buf_stream_offset - d->buf_offset;
}
// Discards the current buffer if we are done with it, make the next buffer
// current if there is one.
static void upb_decoder_advancebuf(upb_decoder *d)
static bool upb_decoder_nextbuf(upb_decoder *d)
{
if(d->buf_bytesleft <= 0) {
if(d->buf) upb_bytesrc_recycle(d->bytesrc, d->buf);
d->buf = d->nextbuf;
d->nextbuf = NULL;
if(d->buf) d->buf_bytesleft += upb_string_len(d->buf);
assert(d->buf_bytesleft < UPB_MAX_ENCODED_SIZE);
// Copy residual bytes to temporary buffer.
if(d->buf_bytesleft > 0) {
memcpy(d->tmpbuf, upb_string_getrobuf(d->buf) + d->buf_offset,
d->buf_bytesleft);
}
}
static bool upb_decoder_pullnextbuf(upb_decoder *d)
{
if(!d->nextbuf && !upb_bytesrc_eof(d->bytesrc)) {
d->nextbuf = upb_bytesrc_get(d->bytesrc, UPB_MAX_ENCODED_SIZE);
if(!d->nextbuf && !upb_bytesrc_eof(d->bytesrc)) {
// There was an error in the byte stream, halt the decoder.
// Recycle old buffer, pull new one.
if(d->buf) {
upb_bytesrc_recycle(d->bytesrc, d->buf);
d->buf_offset -= upb_string_len(d->buf);
d->buf_stream_offset += upb_string_len(d->buf);
}
d->buf = upb_bytesrc_get(d->bytesrc, UPB_MAX_ENCODED_SIZE);
// Handle cases arising from error or EOF.
if(d->buf) {
d->buf_bytesleft += upb_string_len(d->buf);
} else {
if(!upb_bytesrc_eof(d->bytesrc)) {
// Error from bytesrc.
upb_copyerr(&d->src.status, upb_bytesrc_status(d->bytesrc));
return false;
} else if(d->buf_bytesleft == 0) {
// EOF from bytesrc and we don't have any residual bytes left.
d->src.eof = true;
return false;
}
}
return true;
@ -106,11 +118,7 @@ static bool upb_decoder_pullnextbuf(upb_decoder *d)
static bool upb_decoder_skipbytes(upb_decoder *d, int32_t bytes)
{
d->buf_bytesleft -= bytes;
while(d->buf_bytesleft <= 0 && !upb_bytesrc_eof(d->bytesrc)) {
if(!upb_decoder_pullnextbuf(d)) return false;
upb_decoder_advancebuf(d);
}
// TODO.
return true;
}
@ -124,22 +132,28 @@ static upb_strlen_t upb_decoder_append(uint8_t *buf, upb_string *frombuf,
static const uint8_t *upb_decoder_getbuf_full(upb_decoder *d, uint32_t *bytes)
{
if(d->buf_bytesleft < UPB_MAX_ENCODED_SIZE) {
upb_decoder_pullnextbuf(d);
upb_decoder_advancebuf(d);
}
if(d->buf_bytesleft >= UPB_MAX_ENCODED_SIZE) {
if(d->buf_bytesleft < UPB_MAX_ENCODED_SIZE)
if(!upb_decoder_nextbuf(d)) return NULL;
assert(d->buf_bytesleft >= UPB_MAX_ENCODED_SIZE);
if(d->buf_offset >= 0) {
// Common case: the main buffer contains at least UPB_MAX_ENCODED_SIZE
// contiguous bytes, so we can read directly out of it.
*bytes = d->buf_bytesleft;
return (uint8_t*)upb_string_getrobuf(d->buf) + upb_string_len(d->buf) -
d->buf_bytesleft;
return (uint8_t*)upb_string_getrobuf(d->buf) + d->buf_offset;
} else {
upb_strlen_t len = 0;
if(d->buf)
len += upb_decoder_append(d->tmpbuf, d->buf, len, UPB_MAX_ENCODED_SIZE);
if(d->nextbuf)
len += upb_decoder_append(d->tmpbuf, d->nextbuf, len, UPB_MAX_ENCODED_SIZE);
*bytes = len;
memset(d->tmpbuf + len, 0x80, UPB_MAX_ENCODED_SIZE - len);
upb_strlen_t residual_bytes = -d->buf_offset;
if(d->buf) {
memcpy(d->tmpbuf + residual_bytes, upb_string_getrobuf(d->buf),
UPB_MAX_ENCODED_SIZE - residual_bytes);
*bytes = 10;
} else {
// All we have are residual bytes; pad them with 0x80.
memset(d->tmpbuf + residual_bytes, 0x80,
UPB_MAX_ENCODED_SIZE - residual_bytes);
*bytes = residual_bytes;
}
return d->tmpbuf;
}
}
@ -154,12 +168,11 @@ static const uint8_t *upb_decoder_getbuf_full(upb_decoder *d, uint32_t *bytes)
// indicate how many bytes were consumed.
static const uint8_t *upb_decoder_getbuf(upb_decoder *d, uint32_t *bytes)
{
if(d->buf_bytesleft >= UPB_MAX_ENCODED_SIZE) {
// The common case; only when we get to the last ten bytes of the buffer
// do we have to do tricky things.
if(d->buf_bytesleft >= UPB_MAX_ENCODED_SIZE && d->buf_offset >= 0) {
// Common case: the main buffer contains at least UPB_MAX_ENCODED_SIZE
// contiguous bytes, so we can read directly out of it.
*bytes = d->buf_bytesleft;
return (uint8_t*)upb_string_getrobuf(d->buf) + upb_string_len(d->buf) -
d->buf_bytesleft;
return (uint8_t*)upb_string_getrobuf(d->buf) + d->buf_offset;
} else {
return upb_decoder_getbuf_full(d, bytes);
}
@ -168,9 +181,13 @@ static const uint8_t *upb_decoder_getbuf(upb_decoder *d, uint32_t *bytes)
static bool upb_decoder_consume(upb_decoder *d, uint32_t bytes)
{
assert(bytes <= UPB_MAX_ENCODED_SIZE);
//if()
d->buf_offset += bytes;
d->buf_bytesleft -= bytes;
//if(d->buf_bytesleft > upb_string_length())
if(d->buf_offset < 0) {
// We still have residual bytes we have not consumed.
memmove(d->tmpbuf, d->tmpbuf + bytes, -d->buf_offset);
}
return true;
}
@ -208,8 +225,7 @@ INLINE bool upb_decoder_readv64(upb_decoder *d, uint32_t *low, uint32_t *high)
return false;
done:
upb_decoder_consume(d, buf - start);
return true;
return upb_decoder_consume(d, buf - start);
}
// Gets a varint -- called when we only need 32 bits of it. Note that a 32-bit
@ -291,7 +307,6 @@ static uint8_t upb_decoder_skipv64(upb_decoder *d)
/* upb_src implementation for upb_decoder. ************************************/
bool upb_decoder_get_v_uint32(upb_decoder *d, uint32_t *key);
bool upb_decoder_skipval(upb_decoder *d);
upb_fielddef *upb_decoder_getdef(upb_decoder *d)
@ -365,20 +380,20 @@ bool upb_decoder_getval(upb_decoder *d, upb_valueptr val)
d->buf_bytesleft -= total_len;
*val.str = d->str;
} else {
// The string spans buffers, so we must copy from the current buffer,
// the next buffer (if we have one), and finally from the bytesrc.
uint8_t *str = (uint8_t*)upb_string_getrwbuf(d->str, total_len);
upb_strlen_t len = 0;
len += upb_decoder_append(str, d->buf, len, total_len);
upb_decoder_advancebuf(d);
if(d->buf) len += upb_decoder_append(str, d->buf, len, total_len);
upb_string_getrwbuf(d->str, len); // Cheap resize.
if(len < total_len) {
if(!upb_bytesrc_append(d->bytesrc, d->str, total_len - len)) {
upb_copyerr(&d->src.status, upb_bytesrc_status(d->bytesrc));
return false;
}
}
//// The string spans buffers, so we must copy from the current buffer,
//// the next buffer (if we have one), and finally from the bytesrc.
//uint8_t *str = (uint8_t*)upb_string_getrwbuf(d->str, total_len);
//upb_strlen_t len = 0;
//len += upb_decoder_append(str, d->buf, len, total_len);
//upb_decoder_advancebuf(d);
//if(d->buf) len += upb_decoder_append(str, d->buf, len, total_len);
//upb_string_getrwbuf(d->str, len); // Cheap resize.
//if(len < total_len) {
// if(!upb_bytesrc_append(d->bytesrc, d->str, total_len - len)) {
// upb_copyerr(&d->src.status, upb_bytesrc_status(d->bytesrc));
// return false;
// }
//}
}
d->field = NULL;
} else {
@ -521,7 +536,6 @@ upb_decoder *upb_decoder_new(upb_msgdef *msgdef)
d->toplevel_msgdef = msgdef;
d->limit = &d->stack[UPB_MAX_NESTING];
d->buf = NULL;
d->nextbuf = NULL;
d->str = upb_string_new();
upb_src_init(&d->src, &upb_decoder_src_vtbl);
return d;
@ -535,7 +549,6 @@ void upb_decoder_free(upb_decoder *d)
void upb_decoder_reset(upb_decoder *d, upb_bytesrc *bytesrc)
{
if(d->buf) upb_bytesrc_recycle(d->bytesrc, d->buf);
if(d->nextbuf) upb_bytesrc_recycle(d->bytesrc, d->nextbuf);
d->top = d->stack;
d->top->msgdef = d->toplevel_msgdef;
// The top-level message is not delimited (we can keep receiving data for it
@ -544,8 +557,7 @@ void upb_decoder_reset(upb_decoder *d, upb_bytesrc *bytesrc)
d->top->end_offset = UINT32_MAX - 1;
d->bytesrc = bytesrc;
d->buf = NULL;
d->nextbuf = NULL;
d->buf_bytesleft = 0;
d->buf_endoffset = 0;
d->buf_stream_offset = 0;
d->buf_offset = 0;
}

5
src/upb_srcsink.h
Unescape View File

@ -26,6 +26,11 @@
extern "C" {
#endif
// Note! The "eof" flags work like feof() in C; they cannot report end-of-file
// until a read has failed due to eof. They cannot preemptively tell you that
// the next call will fail due to eof. Since these are the semantics that C
// and UNIX provide, we're stuck with them if we want to support eg. stdio.
/* upb_src ********************************************************************/
// TODO: decide how to handle unknown fields.

Write Preview
Loading…
Cancel
Save