gd_putdata(3)

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.

If an error has occurred, the dirfile error will be set to a non-zero value. Possible error values 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 or DIVIDE type, or LINCOM type with more than one input fields. In this case, GetData has no knowledge on how to partition the input data. 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 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 before the beginning-of-frame marker for field_code, or the raw field it depends on.

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.

The dirfile error may be retrieved by calling gd_error(3). A descriptive error string for the last error encountered can be obtained from a call to gd_error_string(3).

SEE ALSO
dirfile(5), dirfile-encoding(5), gd_open(3), gd_error(3), gd_error_string(3), gd_getdata(3), gd_put_carray(3), gd_put_constant(3), gd_seek(3), gd_spf(3), GD_SIZE(3)