Ubuntu Manpage: gd_putdata — write data to a Dirfile database

Provided by: libgetdata-doc_0.11.0-4_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