Ubuntu Manpage: gd_putdata — write data to a Dirfile database

Provided by: libgetdata-doc_0.10.0-6build3_all

NAME

       gd_putdata — write data to a Dirfile database

SYNOPSIS

       #include <getdata.h>

       size_t gd_putdata(DIRFILE *dirfile, const char *field_code, off_t first_frame, off_t first_sample, size_t
              num_frames, size_t num_samples, gd_type_t data_type, const void *data_in);

DESCRIPTION

       The gd_putdata() function writes data to a  dirfile(5)  database  specified  by  dirfile  for  the  field
       field_code,  which may not contain a representation suffix.  It writes num_frames frames plus num_samples
       samples to this field, starting first_sample samples past frame first_frame.  The data is read  from  the
       user-supplied  buffer  data_in,  which  is has a data type specified by data_type.  This interface cannot
       write to field representations.

       The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).

       Unless using GD_HERE (see below), the first sample written will be
              first_frame * samples_per_frame + first_sample
       as measured from the start of the dirfile, where samples_per_frame is the number of samples per frame  as
       returned by gd_spf(3).  The number of samples which gd_putdata() attempts to write is, similarly,
              num_frames * samples_per_frame + num_samples.
       Although calling gd_putdata() using both samples and frames is possible, the function is typically called
       with either num_samples and first_sample, or num_frames and first_frames, equal to zero.

       Instead of explicitly specifying the origin of the write, the caller may pass the special symbol  GD_HERE
       as  first_frame.   This will result in the write occurring at the current position of the I/O pointer for
       the field (see gd_getdata(3) for a discussion of I/O pointers).  In this case, the value of  first_sample
       is ignored.

       The  data_type  argument  should  be  one of the following symbols, which indicates the type of the input
       data:

              GD_UINT8   unsigned 8-bit integer

              GD_INT8 signed (two's complement) 8-bit integer

              GD_UINT16
                      unsigned 16-bit integer

              GD_INT16
                      signed (two's complement) 16-bit integer

              GD_UINT32
                      unsigned 32-bit integer

              GD_INT32
                      signed (two's complement) 32-bit integer

              GD_UINT64
                      unsigned 64-bit integer

              GD_INT64
                      signed (two's complement) 64-bit integer

              GD_FLOAT32
                      IEEE-754 standard 32-bit single precision floating point number

              GD_FLOAT64
                      IEEE-754 standard 64-bit double precision floating point number

              GD_COMPLEX64
                      C99-conformant 64-bit single precision complex number

              GD_COMPLEX128
                      C99-conformant 128-bit double precision complex number

       The type of the input data need not be the same as the type of the data stored  in  the  database.   Type
       conversion will be performed as necessary to write the appropriate type.  The argument data_in must point
       to a valid memory location of containing all the data to be written.

       Upon successful completion, the I/O pointer of the field will be on the sample immediately following  the
       last sample written, if possible.  On error, the position of the I/O pointer is not specified.

RETURN VALUE

In all cases, gd_putdata() returns the number of samples (not bytes) successfully written to the
database, which may be zero if an error has occurred.

On error, this function returns zero and stores a negative-valued error code in the DIRFILE object which
may be retrieved by a subsequent call to gd_error(3). Possible error codes are:

GD_E_ACCMODE
The specified dirfile was opened read-only.

GD_E_ALLOC
The library was unable to allocate memory.

GD_E_BAD_CODE
The field specified by field_code, or one of the fields it uses for input, was not found in the
database.

GD_E_BAD_DIRFILE
An invalid dirfile was supplied.

GD_E_BAD_FIELD_TYPE
Either the field specified by field_code, or one of the fields it uses for input, was of
MULTIPLY, DIVIDE, WINDOW, INDIR, or SINDIR type, or a LINCOM with more than one input field, or a
POLYNOM with quadratic or higer terms. Alternately, the caller may have attempted to write to
the implicit INDEX field, which is not possible.

GD_E_BAD_TYPE
An invalid data_type was specified.

GD_E_DIMENSION
The field specified by field_code was not a vector field. The caller should use
gd_put_carray(3), gd_put_constant(3), or gd_put_string(3) instead. Or, a scalar field was found
where a vector field was expected in the definition of field_code.

GD_E_DOMAIN
An attempt was made to write to a LINTERP field with a look-up table which was not monotonic or
not purely real.

GD_E_INTERNAL_ERROR
An internal error occurred in the library while trying to perform the task. This indicates a bug
in the library. Please report the incident to the maintainer.

GD_E_IO An error occurred while trying to open, read from, or write to a file on disk containing a raw
field or a LINTERP table.

GD_E_LUT
A LINTERP table was malformed.

GD_E_PROTECTED
The data of the RAW field backing field_code was protected from change by a /PROTECT directive.

GD_E_RANGE
An attempt was made to write data either before the beginning-of-frame marker for field_code, or
the raw field it depends on, or else outside the addressable Dirfile range (more than 2**63
samples beyond the start of the Dirfile).

GD_E_RECURSE_LEVEL
Too many levels of recursion were encountered while trying to resolve field_code. This usually
indicates a circular dependency in field specification in the dirfile.

GD_E_UNSUPPORTED
Reading from dirfiles with the encoding scheme of the specified dirfile is not supported by the
library. See dirfile-encoding(5) for details on dirfile encoding schemes.

A descriptive error string for the error may be obtained by calling gd_error_string(3).

NOTES

       When operating on a platform whose size_t is N-bytes wide, a single call of gd_putdata() will never write
       more  than  (2**(N-M)  -  1)  samples,  where  M  is the size, in bytes, of the largest data type used to
       calculate the stored field.  If a larger request is specified, less data than requested will be  written,
       without  raising  an  error.   This  limit  is imposed even when data_type is GD_NULL (i.e., even when no
       actual I/O or calculation occurs).  In all cases, the actual amount of data is returned.

HISTORY