[protobuf] Re: Is there a way to pass C string without triggering construction of string object in C++?
Thanks for fast replay. I understand you matters. You can add mass assignment to your array operations and that would keep you design intact and complete array operation needs. It is already possible to reserve and access entire array but you can only assign one element at a time. On Jan 7, 6:00 pm, Evan Jones ev...@mit.edu wrote: On Jan 7, 2010, at 17:41 , Vlad wrote: inline const ::std::string name() const; //problem here need creation of string - very slow! This doesn't create a string, it just returns a reference to the string already in the protocol buffer object. If you do: const char* c_string = protobuffer.name().data() this gets a pointer to the raw C string inside the C++ string object inside the protocol buffer object. No allocations or copies will be performed. Setting the string, one copy is always performed, as Kenton mentioned. Evan -- Evan Joneshttp://evanjones.ca/ -- You received this message because you are subscribed to the Google Groups Protocol Buffers group. To post to this group, send email to proto...@googlegroups.com. To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/protobuf?hl=en.
[protobuf] Re: Is there a way to pass C string without triggering construction of string object in C++?
Cool Will do. thanks On Jan 8, 12:44 pm, Kenton Varda ken...@google.com wrote: On Fri, Jan 8, 2010 at 5:48 AM, Vlad vladimir.sakha...@gmail.com wrote: You can add mass assignment to your array operations and that would keep you design intact and complete array operation needs. It is already possible to reserve and access entire array but you can only assign one element at a time. Just use a loop. On any modern compiler it will be just as fast as if we had provided some sort of mass assignment method. On Jan 7, 6:00 pm, Evan Jones ev...@mit.edu wrote: On Jan 7, 2010, at 17:41 , Vlad wrote: inline const ::std::string name() const; //problem here need creation of string - very slow! This doesn't create a string, it just returns a reference to the string already in the protocol buffer object. If you do: const char* c_string = protobuffer.name().data() this gets a pointer to the raw C string inside the C++ string object inside the protocol buffer object. No allocations or copies will be performed. Setting the string, one copy is always performed, as Kenton mentioned. Evan -- Evan Joneshttp://evanjones.ca/ -- You received this message because you are subscribed to the Google Groups Protocol Buffers group. To post to this group, send email to proto...@googlegroups.com. To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.comprotobuf%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/protobuf?hl=en. -- You received this message because you are subscribed to the Google Groups Protocol Buffers group. To post to this group, send email to proto...@googlegroups.com. To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/protobuf?hl=en.
[protobuf] Re: Is there a way to pass C string without triggering construction of string object in C++?
Tried trivial object:
proto::TestVector tv;
tv.mutable_name()-Reserve(length);
Strange thing happens: Above code calls memcpy...
#callq 0x404e98 mem...@plt
even if I do not assign anything.
Good side the following was indeed converted to memcpy.
for(int i=0; ilength; ++i,++zz){
tv.add_name(*zz);
}
but it still has 2 pages of assembler in front of it.
(g++ 4.1.2 with -O2)
On Jan 8, 1:45 pm, Vlad vladimir.sakha...@gmail.com wrote:
Cool
Will do.
thanks
On Jan 8, 12:44 pm, Kenton Varda ken...@google.com wrote:
On Fri, Jan 8, 2010 at 5:48 AM, Vlad vladimir.sakha...@gmail.com wrote:
You can add mass assignment to your array operations and that would
keep you design intact and complete array operation needs.
It is already possible to reserve and access entire array but you can
only assign one element at a time.
Just use a loop. On any modern compiler it will be just as fast as if we
had provided some sort of mass assignment method.
On Jan 7, 6:00 pm, Evan Jones ev...@mit.edu wrote:
On Jan 7, 2010, at 17:41 , Vlad wrote:
inline const ::std::string name() const; //problem here need
creation of string - very slow!
This doesn't create a string, it just returns a reference to the
string already in the protocol buffer object. If you do:
const char* c_string = protobuffer.name().data()
this gets a pointer to the raw C string inside the C++ string object
inside the protocol buffer object. No allocations or copies will be
performed. Setting the string, one copy is always performed, as Kenton
mentioned.
Evan
--
Evan Joneshttp://evanjones.ca/
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[protobuf] Re: Is there a way to pass C string without triggering construction of string object in C++?
Tried trivial object:
proto::TestVector tv;
tv.mutable_name()-Reserve(length);
Strange thing happens: Above code calls memcpy...
#callq 0x404e98 mem...@plt
even if I do not assign anything.
Good side the following was indeed converted to memcpy.
for(int i=0; ilength; ++i,++zz){
tv.add_name(*zz);
}
but it still has 2 pages of assembler in front of it.
(g++ 4.1.2 with -O2)
On Jan 8, 1:45 pm, Vlad vladimir.sakha...@gmail.com wrote:
Cool
Will do.
thanks
On Jan 8, 12:44 pm, Kenton Varda ken...@google.com wrote:
On Fri, Jan 8, 2010 at 5:48 AM, Vlad vladimir.sakha...@gmail.com wrote:
You can add mass assignment to your array operations and that would
keep you design intact and complete array operation needs.
It is already possible to reserve and access entire array but you can
only assign one element at a time.
Just use a loop. On any modern compiler it will be just as fast as if we
had provided some sort of mass assignment method.
On Jan 7, 6:00 pm, Evan Jones ev...@mit.edu wrote:
On Jan 7, 2010, at 17:41 , Vlad wrote:
inline const ::std::string name() const; //problem here need
creation of string - very slow!
This doesn't create a string, it just returns a reference to the
string already in the protocol buffer object. If you do:
const char* c_string = protobuffer.name().data()
this gets a pointer to the raw C string inside the C++ string object
inside the protocol buffer object. No allocations or copies will be
performed. Setting the string, one copy is always performed, as Kenton
mentioned.
Evan
--
Evan Joneshttp://evanjones.ca/
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[protobuf] Re: Is there a way to pass C string without triggering construction of string object in C++?
Tried trivial object:
proto::TestVector tv;
tv.mutable_name()-Reserve(length);
Strange thing happens: Above code calls memcpy...
#callq 0x404e98 mem...@plt
even if I do not assign anything.
Good side the following was indeed converted to memcpy.
for(int i=0; ilength; ++i,++zz){
tv.add_name(*zz);
}
but it still has 2 pages of assembler in front of it.
(g++ 4.1.2 with -O2)
On Jan 8, 1:45 pm, Vlad vladimir.sakha...@gmail.com wrote:
Cool
Will do.
thanks
On Jan 8, 12:44 pm, Kenton Varda ken...@google.com wrote:
On Fri, Jan 8, 2010 at 5:48 AM, Vlad vladimir.sakha...@gmail.com wrote:
You can add mass assignment to your array operations and that would
keep you design intact and complete array operation needs.
It is already possible to reserve and access entire array but you can
only assign one element at a time.
Just use a loop. On any modern compiler it will be just as fast as if we
had provided some sort of mass assignment method.
On Jan 7, 6:00 pm, Evan Jones ev...@mit.edu wrote:
On Jan 7, 2010, at 17:41 , Vlad wrote:
inline const ::std::string name() const; //problem here need
creation of string - very slow!
This doesn't create a string, it just returns a reference to the
string already in the protocol buffer object. If you do:
const char* c_string = protobuffer.name().data()
this gets a pointer to the raw C string inside the C++ string object
inside the protocol buffer object. No allocations or copies will be
performed. Setting the string, one copy is always performed, as Kenton
mentioned.
Evan
--
Evan Joneshttp://evanjones.ca/
--
You received this message because you are subscribed to the Google Groups
Protocol Buffers group.
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protobuf+unsubscr...@googlegroups.comprotobuf%2bunsubscr...@googlegroups.com
.
For more options, visit this group at
http://groups.google.com/group/protobuf?hl=en.
--
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