VOLK_Codec Struct Reference

Prototype for initializing a dataset decoding loop. More...

#include <codec_interface.h>

Collaboration diagram for VOLK_Codec:

Data Fields
decode_ds_fn_t	decode_dset
	dataset decoder initialization.
decode_gr_fn_t	decode_graph
	Graph decoder function.
decode_term_fn_t	decode_term
	Term decoder function.
encode_ds_done_fn_t	encode_dset_done
	dataset encoder finalization.
encode_ds_init_fn_t	encode_dset_init
	dataset encoder initialization.
encode_ds_iter_fn_t	encode_dset_iter
	dataset encoder iteration.
encode_gr_done_fn_t	encode_graph_done
	Graph encoder finalization.
encode_gr_init_fn_t	encode_graph_init
	Graph encoder initialization.
encode_gr_iter_fn_t	encode_graph_iter
	Graph encoder iteration.
encode_store_done_fn_t	encode_store_done
	store encoder finalization.
encode_store_init_fn_t	encode_store_init
	store encoder initialization.
encode_store_iter_fn_t	encode_store_iter
	store encoder iteration.
encode_term_fn_t	encode_term
	Feature flags.
char	extension [8]
	Serialized file extension.
VOLK_CodecFeatures	features
char	mimetype [32]
	MIME type associated with the codec.
char	name [16]
	Name of the codec.

Detailed Description

Prototype for initializing a dataset decoding loop.

@TODO remove in favor of one-pass dataset encoding.

Parameters

[in]	fh	Open file handle pointing to the RDF data. Implementations MUST NOT close the file handle. This is exclusive with sh.
[in]	sh	string handle for the RDF data. This is exclusive with fh. If both are specified, fh has precedence.

Returns

Pointer to opaque data to be passed to #decode_ds_iter_fn_t and #decode_ds_done_fn_t.

Prototype for decoding one graph in a dataset.

@TODO remove in favor of one-pass dataset encoding.

Parameters

[in]	it	Opaque iterator handle obtained by #decode_ds_init_fn_t.
[out]	gr	Graph handle pointer to be populated with decoded graphs. The handle MUST NOT be initialized.
[out]	ct	If not NULL, it MAY be populated with the number of triples parsed (which may be different from the resulting graph size). Implementations MAY choose not not use this.
[out]	err	Pointer to error info string. If no error occurs, it yields NULL.

Returns

Implementations MUST return VOLK_OK on success and a negative value on parsing error.

Prototype for finalizing a dataset decoder iterator.

@TODO remove in favor of one-pass dataset encoding.

Parameters

[in]

it

Opaque iterator handle obtained by #decode_ds_init_fn_t.

Codec structure.

An instance of this structure is a singleton defined at compile time (see examples in "include/codec_*.h" and "src/codec_*.c") and MUST have the following defined:

• name: A brief (15-char max), human-readable name for the codec.
• mimetype: MIME type (31-char max) associated with the codec.
• extension: File extension associated with the serialized file.

Additionally, it MAY implement any of the following encoding and decoding functions, depending on the scope of the codec:

• encode_term: Encode a single term.
• encode_graph_init: Initialize a graph decoding loop.
• encode_graph_iter: Run one iteration of encoding on one or more triples.
• encode_graph_done: Finalize the encoding loop and free the support data.
• encode_dset_*: encode a dataset with zero or more graphs.
• decode_term: Decode a single term.
• decode_graph: Decode a RDF document into a graph.
• decode_dset: Decode a RDF document into a dataset with zero or more graphs.

For documentation on the individual encoding and decoding callbacks, see the related function prototypes.

This interface is abstracted by the high-level codec module. That module handles non-implemented functionality gracefully by returning VOLK_NOT_IMPL_ERR.

Note

Functions in the high-level codec module do not check if a function is defined, they only look at the features flags to decide whether a function can be called. Therefore, implementers must be careful to match the implemented functions with the feature flags.

Definition at line 552 of file codec_interface.h.

Field Documentation

decode_dset

decode_ds_fn_t VOLK_Codec::decode_dset

dataset decoder initialization.

Definition at line 578 of file codec_interface.h.

decode_graph

decode_gr_fn_t VOLK_Codec::decode_graph

Graph decoder function.

Definition at line 576 of file codec_interface.h.

decode_term

decode_term_fn_t VOLK_Codec::decode_term

Term decoder function.

Definition at line 574 of file codec_interface.h.

encode_dset_done

encode_ds_done_fn_t VOLK_Codec::encode_dset_done

dataset encoder finalization.

Definition at line 567 of file codec_interface.h.

encode_dset_init

encode_ds_init_fn_t VOLK_Codec::encode_dset_init

dataset encoder initialization.

Definition at line 565 of file codec_interface.h.

encode_dset_iter

encode_ds_iter_fn_t VOLK_Codec::encode_dset_iter

dataset encoder iteration.

Definition at line 566 of file codec_interface.h.

encode_graph_done

encode_gr_done_fn_t VOLK_Codec::encode_graph_done

Graph encoder finalization.

Definition at line 563 of file codec_interface.h.

encode_graph_init

encode_gr_init_fn_t VOLK_Codec::encode_graph_init

Graph encoder initialization.

Definition at line 561 of file codec_interface.h.

encode_graph_iter

encode_gr_iter_fn_t VOLK_Codec::encode_graph_iter

Graph encoder iteration.

Definition at line 562 of file codec_interface.h.

encode_store_done

encode_store_done_fn_t VOLK_Codec::encode_store_done

store encoder finalization.

Definition at line 571 of file codec_interface.h.

encode_store_init

encode_store_init_fn_t VOLK_Codec::encode_store_init

store encoder initialization.

Definition at line 569 of file codec_interface.h.

encode_store_iter

encode_store_iter_fn_t VOLK_Codec::encode_store_iter

store encoder iteration.

Definition at line 570 of file codec_interface.h.

encode_term

encode_term_fn_t VOLK_Codec::encode_term

Feature flags.

Term encoder function.

Definition at line 559 of file codec_interface.h.

extension

char VOLK_Codec::extension[8]

Serialized file extension.

Definition at line 555 of file codec_interface.h.

features

VOLK_CodecFeatures VOLK_Codec::features

Definition at line 556 of file codec_interface.h.

mimetype

char VOLK_Codec::mimetype[32]

MIME type associated with the codec.

Definition at line 554 of file codec_interface.h.

name

char VOLK_Codec::name[16]

Name of the codec.

Definition at line 553 of file codec_interface.h.

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The documentation for this struct was generated from the following file:

• include/volksdata/codec_interface.h