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/*
* <Copyright>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY
* THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* liberasurecode backend API definition
*
* vi: set noai tw=79 ts=4 sw=4:
*/
#ifndef _ERASURECODE_BACKEND_H_
#define _ERASURECODE_BACKEND_H_
#include "list.h"
#include "erasurecode.h"
#include "erasurecode_stdinc.h"
/* ~=*=~===~=*=~==~=*=~==~=*=~= backend infrastructure =~=*=~==~=*=~==~=*=~ */
#ifdef __cplusplus
extern "C" {
#endif
#if defined (__GNUC__) && __GNUC__ > 3
#define dl_restrict __restrict
#else
#define dl_restrict
#endif
/* ==~=*=~===~=*=~==~=*=~==~=*=~= EC backend args =~==~=*=~==~=*=~===~=*=~== */
/* Arguments passed to the backend */
#define MAX_PRIV_ARGS 4
struct ec_backend_args {
struct ec_args uargs; /* common args passed in by the user */
void *pargs[MAX_PRIV_ARGS]; /* used for private backend args */
};
/* =~===~=*=~==~=*=~==~=*=~= backend stub definitions =~=*=~==~=*=~==~=*=~= */
#define INIT init
#define EXIT exit
#define ENCODE encode
#define DECODE decode
#define FRAGSNEEDED fragments_needed
#define RECONSTRUCT reconstruct
#define ELEMENTSIZE element_size
#define ISCOMPATIBLEWITH is_compatible_with
#define FN_NAME(s) str(s)
#define str(s) #s
/* EC backend stubs - implemented per backend */
struct ec_backend_op_stubs {
/** Backend register/init, unregister/cleanup routines **/
/* Private backend init routine */
void * (*INIT)(struct ec_backend_args *args, void *sohandle);
/* Private backend cleanup routine */
int (*EXIT)(void *);
/* Backend stub declarations */
int (*ENCODE)(void *desc,
char **data, char **parity, int blocksize);
int (*DECODE)(void *desc,
char **data, char **parity, int *missing_idxs, int blocksize);
int (*FRAGSNEEDED)(void *desc,
int *missing_idxs, int * fragments_to_exclude, int *fragments_needed);
int (*RECONSTRUCT)(void *desc,
char **data, char **parity, int *missing_idxs, int destination_idx,
int blocksize);
int (*ELEMENTSIZE)(void *desc);
bool (*ISCOMPATIBLEWITH) (uint32_t version);
};
/* ==~=*=~==~=*=~==~=*=~= backend struct definitions =~=*=~==~=*=~==~=*==~== */
struct ec_backend_desc {
void *backend_desc; /* EC backend private descriptor */
void *backend_sohandle; /* EC backend shared lib handle */
};
#define MAX_LEN 64
/* EC backend common attributes */
struct ec_backend_common {
ec_backend_id_t id; /* EC backend type */
char name[MAX_LEN]; /* EC backend common name */
const char *soname; /* EC backend shared library path */
char soversion[MAX_LEN]; /* EC backend shared library version */
struct ec_backend_op_stubs *ops; /* EC backend stubs */
size_t backend_metadata_size;
/* EC backend custom metadata size -
* backend_metadata_size bytes are added to
* the fragment size when allocating
* data/parity fragment buffers */
uint32_t ec_backend_version; /* The revision number of this back
* end. Is used to determine whether
* a specific instance of this backend
* accepts fragments generated by
* another version */
};
/* EC backend definition */
typedef struct ec_backend {
struct ec_backend_common common; /* EC backend common attributes */
struct ec_backend_args args; /* EC backend instance data (private) */
int idesc; /* liberasurecode instance handle */
struct ec_backend_desc desc; /* EC backend instance handle */
SLIST_ENTRY(ec_backend) link;
} *ec_backend_t;
/* ~=*=~==~=*=~==~=*=~==~=*= frontend <-> backend API =*=~==~=*=~==~=*=~==~= */
/* Register a backend instance with liberasurecode */
int liberasurecode_backend_instance_register(ec_backend_t instance);
/* Unregister a backend instance */
int liberasurecode_backend_instance_unregister(ec_backend_t instance);
/* Generic dlopen/dlclose routines */
int liberasurecode_backend_open(ec_backend_t instance);
int liberasurecode_backend_close(ec_backend_t instance);
/* Backend query interface */
/* Name to ID mapping for EC backend */
ec_backend_id_t liberasurecode_backend_lookup_id(const char *name);
/* Get EC backend by name */
ec_backend_t liberasurecode_backend_lookup_by_name(const char *name);
/**
* Look up a backend instance by descriptor
*
* Returns pointer to a registered liberasurecode instance
* The caller must hold active_instances_rwlock
*/
ec_backend_t liberasurecode_backend_instance_get_by_desc(int desc);
/* =~=*=~==~=*=~==~=*=~==~=*=~===~=*=~==~=*=~===~=*=~==~=*=~===~=*=~==~=*=~= */
#ifdef __cplusplus
}
#endif
#endif // _ERASURECODE_BACKEND_H_
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