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/* nbdkit
* Copyright Red Hat
*
* 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.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT 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 RED HAT 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.
*/
/* See nbdkit-plugin(3) for documentation and how to write a plugin. */
#ifndef NBDKIT_PLUGIN_H
#define NBDKIT_PLUGIN_H
#include <nbdkit-common.h>
#ifdef __cplusplus
extern "C" {
#endif
/* By default, a plugin gets API version 1; but you may request
* version 2 prior to including this header */
#ifndef NBDKIT_API_VERSION
#define NBDKIT_API_VERSION 1
#elif (NBDKIT_API_VERSION - 0) < 1 || NBDKIT_API_VERSION > 2
#error Unsupported API version
#endif
struct nbdkit_plugin {
/* Do not set these fields directly; use NBDKIT_REGISTER_PLUGIN.
* They exist so that we can support plugins compiled against
* one version of the header with a runtime compiled against a
* different version with more (or fewer) fields.
*/
uint64_t _struct_size;
int _api_version;
int _thread_model;
/* Plugins are responsible for these fields; see the documentation
* for semantics, and which fields are optional. New fields will
* only be added at the end of the struct.
*/
const char *name;
const char *longname;
const char *version;
const char *description;
void (*load) (void);
void (*unload) (void);
int (*config) (const char *key, const char *value);
int (*config_complete) (void);
const char *config_help;
void * (*open) (int readonly);
void (*close) (void *handle);
int64_t (*get_size) (void *handle);
int (*can_write) (void *handle);
int (*can_flush) (void *handle);
int (*is_rotational) (void *handle);
int (*can_trim) (void *handle);
#if NBDKIT_API_VERSION == 1
int (*pread) (void *handle, void *buf, uint32_t count, uint64_t offset);
int (*pwrite) (void *handle, const void *buf, uint32_t count,
uint64_t offset);
int (*flush) (void *handle);
int (*trim) (void *handle, uint32_t count, uint64_t offset);
int (*zero) (void *handle, uint32_t count, uint64_t offset, int may_trim);
#else
int (*_pread_v1) (void *, void *, uint32_t, uint64_t);
int (*_pwrite_v1) (void *, const void *, uint32_t, uint64_t);
int (*_flush_v1) (void *);
int (*_trim_v1) (void *, uint32_t, uint64_t);
int (*_zero_v1) (void *, uint32_t, uint64_t, int);
#endif
int errno_is_preserved;
void (*dump_plugin) (void);
int (*can_zero) (void *handle);
int (*can_fua) (void *handle);
#if NBDKIT_API_VERSION == 1
int (*_unused1) (void *, void *, uint32_t, uint64_t, uint32_t);
int (*_unused2) (void *, const void *, uint32_t, uint64_t, uint32_t);
int (*_unused3) (void *, uint32_t);
int (*_unused4) (void *, uint32_t, uint64_t, uint32_t);
int (*_unused5) (void *, uint32_t, uint64_t, uint32_t);
#else
int (*pread) (void *handle, void *buf, uint32_t count, uint64_t offset,
uint32_t flags);
int (*pwrite) (void *handle, const void *buf, uint32_t count,
uint64_t offset, uint32_t flags);
int (*flush) (void *handle, uint32_t flags);
int (*trim) (void *handle, uint32_t count, uint64_t offset, uint32_t flags);
int (*zero) (void *handle, uint32_t count, uint64_t offset, uint32_t flags);
#endif
const char *magic_config_key;
int (*can_multi_conn) (void *handle);
int (*can_extents) (void *handle);
int (*extents) (void *handle, uint32_t count, uint64_t offset, uint32_t flags,
struct nbdkit_extents *extents);
int (*can_cache) (void *handle);
int (*cache) (void *handle, uint32_t count, uint64_t offset, uint32_t flags);
int (*thread_model) (void);
int (*can_fast_zero) (void *handle);
int (*preconnect) (int readonly);
int (*get_ready) (void);
int (*after_fork) (void);
int (*list_exports) (int readonly, int is_tls,
struct nbdkit_exports *exports);
const char * (*default_export) (int readonly, int is_tls);
const char * (*export_description) (void *handle);
void (*cleanup) (void);
int (*block_size) (void *handle,
uint32_t *minimum, uint32_t *preferred, uint32_t *maximum);
};
NBDKIT_EXTERN_DECL (void, nbdkit_set_error, (int err));
NBDKIT_EXTERN_DECL (const char *, nbdkit_export_name, (void));
NBDKIT_EXTERN_DECL (int, nbdkit_is_tls, (void));
#define NBDKIT_REGISTER_PLUGIN(plugin) \
NBDKIT_CXX_LANG_C \
NBDKIT_DLL_PUBLIC \
struct nbdkit_plugin * \
plugin_init (void) \
{ \
(plugin)._struct_size = sizeof (plugin); \
(plugin)._api_version = NBDKIT_API_VERSION; \
(plugin)._thread_model = THREAD_MODEL; \
return &(plugin); \
}
#ifdef __cplusplus
}
#endif
#endif /* NBDKIT_PLUGIN_H */
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