putdata (3) - Linux Man Pages

putdata: write data to a dirfile database

NAME

putdata --- write data to a dirfile database

SYNOPSIS

#include <getdata.h>
size_t 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 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 dirfile_open(3).

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 get_spf(3). The number of samples which putdata() attempts to write is, similarly,
num_frames * samples_per_frame + num_samples.
Although calling 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.

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~or~GD_FLOAT
IEEE-754 standard 32-bit single precision floating point number
GD_FLOAT64~or~GD_DOUBLE
IEEE-754 standard 64-bit double precision floating point 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.

RETURN VALUE

In all cases, 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 type, or LINCOM type with more than one input fields. In this case, putdata() 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_REPR
The representation suffix specified in field_code was not recognised, or an attempt was made to write to a field representation, instead of the underlying field.
GD_E_BAD_TYPE
An invalid data_type was specified.
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_OPEN_LINFILE
An error occurred while trying to read a LINTERP table from disk.
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_RAW_IO
An error occurred while trying to open, read from, or write to a file on disk containing a raw field.
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 get_error(3). A descriptive error string for the last error encountered can be obtained from a call to get_error_string(3).