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Re: including a new gnulib module
From: |
Ben Abbott |
Subject: |
Re: including a new gnulib module |
Date: |
Mon, 30 Jul 2012 19:25:11 -0400 |
On Jul 29, 2012, at 1:23 PM, c. wrote:
>
> Il giorno 26/lug/2012, alle ore 15.42, John W. Eaton ha scritto:
>
>> On 26-Jul-2012, c. wrote:
>>
>> | > Here is a new version of the changeset that adds the new functions in
>> data.cc (and links fine)
>> | > I can't push it at the moment as the connection to the mercurial repo at
>> savannah
>> | > appears to be down.
>> | >
>> | > BTW, is there a better way than copying data as I did in this
>> implementation to create
>> | > an Array<double> from double[] ?
>>
>> If you can compute the length of the array separate from allocating
>> and filling it, then you could do something like
>>
>> octave_idx_type needed_length = ...;
>> Array<double> buffer (needed_length);
>> function_that_fills_buffer (buffer.fortran_vec ());
>>
>> | +extern "C"
>> | +{
>> | +#include <base64.h>
>> | +}
>>
>> We should probably ask the gnulib maintainers to add extern "C" to the
>> base64.h header file.
>>
>> | + Array<double> in = args(0).array_value ();
>>
>> This should probably be const Array<double> since you aren't modifying
>> it.
>>
>> | + if (! error_state)
>> | + {
>> | + char* inc = (char*) in.fortran_vec ();
>>
>> If you don't plan to modify the IN vector, then use data () instead of
>> fortran_vec. That way you won't force an unnecessary copy if there is
>> more than one reference to the data in the input argument to
>> base64_encode.
>>
>> In Octave code, we prefer to avoid casts if possible, but if they are
>> necessary, then we prefer to use C++-style casts because they are
>> easier to find.
>>
>> | + size_t inlen = in.numel () * sizeof (double) / sizeof (char);
>> | +
>> | + char* out;
>> | +
>> | + size_t outlen = base64_encode_alloc (inc, inlen, &out);
>> | + if (out == NULL && outlen == 0 && inlen != 0)
>>
>> In C++, it's almost never necessary to use NULL. 0 usually works
>> fine. Or write "!out" instead of "out == 0".
>>
>> | + error ("base64_encode: input array too large.");
>> | + else if (out == NULL)
>> | + error ("base64_encode: memory allocation error.");
>>
>> For consistency with other messages in Octave, we don't end error
>> messages in periods.
>>
>> | + std::string s (out);
>> | + retval(0) = octave_value (s);
>>
>> You should be able to avoid creating the std::string object here.
>> There is an
>>
>> octave_value (const char *s, char type = '\'');
>>
>> constructor. The type says whether it is a single- or double-quoted
>> string. I would write
>>
>> retval(0) = octave_value (out);
>>
>> to use the default and construct a single-quoted string here.
>>
>> Also, there is an octave_value_list constructor that converts a single
>> octave_value object to an octave_value_list object with one element,
>> so you could write
>>
>> return octave_value (out);
>>
>> Finally, the error function simply returns, so lines that follow are
>> still executed. Is that OK to do here, or should you be returning
>> early? For example:
>>
>> if (! out && outlen == 0 && inlen != 0)
>> {
>> error ("base64_encode: input array too large");
>> return retval;
>> }
>> else if (! out)
>> {
>> error ("base64_encode: memory allocation error");
>> return retval;
>> }
>>
>> or
>>
>> if (! out && outlen == 0 && inlen != 0)
>> error ("base64_encode: input array too large");
>> else if (! out)
>> error ("base64_encode: memory allocation error");
>>
>> if (error_state)
>> return retval;
>>
>> jwe
>
> I just pushed a changeset that addresses most [*] of the comments above
> and adds tests:
>
> http://hg.savannah.gnu.org/hgweb/octave/rev/abc858bc5165
>
> c.
>
> [*] I still need the 'extern "C"' in data.cc until I manage to have that
> moved upstream,
> I'll now try to contatct the gnulib people about this
I'm seeing the error below.
data.cc:43:20: fatal error: base64.h: No such file or directory
Ben
- Re: including a new gnulib module, (continued)
- Re: including a new gnulib module, c., 2012/07/24
- Re: including a new gnulib module, John W. Eaton, 2012/07/24
- Re: including a new gnulib module, c., 2012/07/26
- Re: including a new gnulib module, c., 2012/07/26
- Re: including a new gnulib module, Max Brister, 2012/07/26
- Re: including a new gnulib module, c., 2012/07/26
- Re: including a new gnulib module, Max Brister, 2012/07/26
- Re: including a new gnulib module, John W. Eaton, 2012/07/26
- Re: including a new gnulib module, John W. Eaton, 2012/07/26
- Re: including a new gnulib module, c., 2012/07/29
- Re: including a new gnulib module,
Ben Abbott <=
- Re: including a new gnulib module, Ben Abbott, 2012/07/30
- Re: including a new gnulib module, John W. Eaton, 2012/07/31
- Re: including a new gnulib module, Ben Abbott, 2012/07/31
- Re: including a new gnulib module, Jordi GutiƩrrez Hermoso, 2012/07/31