[protobuf] Re: Secret Message Pre-Header
The first 8 bytes is some kind of header.
the next two bytes are varint tag with field number 1 and interger value =
0
next 6 bytes is also varint tag with field number 2 and value = {five byes}
next 2 bytes says it is a string or byte array with with 6 bytes long. :)
On Tuesday, May 19, 2015 at 11:54:01 PM UTC+2, Jim Muchow wrote:
I sent a question yesterday, but I don't see it as having been posted,
much less
responded to. My apologies for the redundancy if my original message is in
some
queue somewhere.
**
I'm trying to determine the utility of Valgrind in an app. The app uses
protocol buffers.
I am seeing a message from Valgrind
Syscall param write(buf) points to uninitialised byte(s)
with the following info
Address 0x11c7fa02 is 2 bytes inside a block of size 8,192 alloc'd
At first, I thought it might be one of the fields in a message declared
optional, but
when I filled out the field, I got the same warning. In the process of
looking into this
more closely I was able to dump the buffer:
0x000x010xc10x090x000x000x000x10 secret,
pre-header?
0x080x000x100xa50xcb0x960xad0x0a
0x1a0x060x610x700x610x630x680x65
The latter 16 bytes are the message proper with three fields and I
understand how
they are created and interpreted from the Encoding spec (very helpful). It
is the first
eight bytes I don't understand.
These first bytes are almost like a secret pre-header. It looks to me as
if the last four
bytes are a 32-bit length field. The number matches in this case and in
the other case in
which the optional field was left unset. I can't figure what the first
four bytes indicate. In
particular, the bytes 0xc1 and 0x09, which would start the area of the
supposedly
uninitialized bytes.
Is there somewhere in the code I can look to see how this pre-header is
created. Or I
would be happy to research this myself if some documentation exists, but I
don't know
where to start looking.
Thanks for any help,
jdm
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[protobuf] Re: Secret Message Pre-Header
follow up to my previous post... the first four byte is out of my imagination, but the next 4 bytes indicates 16 that should be the following message size. On Tuesday, May 19, 2015 at 11:54:01 PM UTC+2, Jim Muchow wrote: I sent a question yesterday, but I don't see it as having been posted, much less responded to. My apologies for the redundancy if my original message is in some queue somewhere. ** I'm trying to determine the utility of Valgrind in an app. The app uses protocol buffers. I am seeing a message from Valgrind Syscall param write(buf) points to uninitialised byte(s) with the following info Address 0x11c7fa02 is 2 bytes inside a block of size 8,192 alloc'd At first, I thought it might be one of the fields in a message declared optional, but when I filled out the field, I got the same warning. In the process of looking into this more closely I was able to dump the buffer: 0x000x010xc10x090x000x000x000x10 secret, pre-header? 0x080x000x100xa50xcb0x960xad0x0a 0x1a0x060x610x700x610x630x680x65 The latter 16 bytes are the message proper with three fields and I understand how they are created and interpreted from the Encoding spec (very helpful). It is the first eight bytes I don't understand. These first bytes are almost like a secret pre-header. It looks to me as if the last four bytes are a 32-bit length field. The number matches in this case and in the other case in which the optional field was left unset. I can't figure what the first four bytes indicate. In particular, the bytes 0xc1 and 0x09, which would start the area of the supposedly uninitialized bytes. Is there somewhere in the code I can look to see how this pre-header is created. Or I would be happy to research this myself if some documentation exists, but I don't know where to start looking. Thanks for any help, jdm -- You received this message because you are subscribed to the Google Groups Protocol Buffers group. To unsubscribe from this group and stop receiving emails from it, send an email to protobuf+unsubscr...@googlegroups.com. To post to this group, send email to protobuf@googlegroups.com. Visit this group at http://groups.google.com/group/protobuf. For more options, visit https://groups.google.com/d/optout.
