1NBDKit(3)                                                            NBDKit(3)
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3
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NAME

6       NBDKit  -  Interface  between  plugins  written in OCaml and the nbdkit
7       server.
8

Module

10       Module   NBDKit
11

Documentation

13       Module NBDKit
14        : sig end
15
16
17       Interface between plugins written in OCaml and the nbdkit server.
18
19       Read these man pages for additional information: nbdkit-ocaml-plugin(3)
20       and nbdkit-plugin(3)
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24
25
26       type flags = flag list
27
28
29       Flags passed from the server to various callbacks.
30
31
32       type flag =
33        | May_trim
34        | FUA
35        | Req_one
36
37
38
39
40       type fua_flag =
41        | FuaNone
42        | FuaEmulate
43        | FuaNative
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45
46
47
48       type cache_flag =
49        | CacheNone
50        | CacheEmulate
51        | CacheNop
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53
54
55
56       type extent = {
57        offset : int64 ;
58        length : int64 ;
59        is_hole : bool ;
60        is_zero : bool ;
61        }
62
63
64       The type of the extent list returned by extents
65
66
67
68       type export = {
69        name : string ;
70        description : string option ;
71        }
72
73
74       The type of the export list returned by list_exports
75
76
77
78       type thread_model =
79        | THREAD_MODEL_SERIALIZE_CONNECTIONS
80        | THREAD_MODEL_SERIALIZE_ALL_REQUESTS
81        | THREAD_MODEL_SERIALIZE_REQUESTS
82        | THREAD_MODEL_PARALLEL
83
84
85       The type of the thread model returned by thread_model
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88
89
90       val   register_plugin   :  name:string  ->  ?longname:string  ->  ?ver‐
91       sion:string  ->  ?description:string  ->  ?load:(unit   ->   unit)   ->
92       ?get_ready:(unit   ->   unit)   ->   ?after_fork:(unit   ->   unit)  ->
93       ?cleanup:(unit -> unit) -> ?unload:(unit -> unit) -> ?config:(string ->
94       string   ->   unit)   ->   ?config_complete:(unit  ->  unit)  ->  ?con‐
95       fig_help:string -> ?thread_model:(unit -> thread_model) ->  ?magic_con‐
96       fig_key:string  ->  ?preconnect:(bool -> unit) -> open_connection:(bool
97       -> 'a) -> ?close:('a -> unit) -> get_size:('a -> int64) ->  ?export_de‐
98       scription:('a  ->  string)  -> ?block_size:('a -> int * int * int64) ->
99       ?can_cache:('a  ->  cache_flag)  ->  ?can_extents:('a   ->   bool)   ->
100       ?can_fast_zero:('a  -> bool) -> ?can_flush:('a -> bool) -> ?can_fua:('a
101       -> fua_flag) -> ?can_multi_conn:('a -> bool) -> ?can_trim:('a ->  bool)
102       ->  ?can_write:('a  ->  bool)  ->  ?can_zero:('a  -> bool) -> ?is_rota‐
103       tional:('a -> bool) -> pread:('a -> int -> int64 -> flags -> string) ->
104       ?pwrite:('a -> string -> int64 -> flags -> unit) -> ?flush:('a -> flags
105       -> unit) -> ?trim:('a -> int64 -> int64 -> flags -> unit) ->  ?zero:('a
106       ->  int64  -> int64 -> flags -> unit) -> ?extents:('a -> int64 -> int64
107       -> flags -> extent list) -> ?cache:('a -> int64 -> int64  ->  flags  ->
108       unit)  -> ?dump_plugin:(unit -> unit) -> ?list_exports:(bool -> bool ->
109       export list) -> ?default_export:(bool -> bool ->  string)  ->  unit  ->
110       unit
111
112       Register the plugin with nbdkit.
113
114       The  'a  parameter  is the handle type returned by your open_connection
115       method and passed back to all connected calls.
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118
119       val set_error : Unix.error -> unit
120
121       Set the errno returned over the NBD protocol to the client.
122
123       Notice however that the NBD protocol only supports a small  handful  of
124       errno values.  Any other errno will be translated into EINVAL .
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126
127
128       val parse_size : string -> int64
129
130       Bindings   for  nbdkit_parse_size  ,  nbdkit_parse_probability  ,  nbd‐
131       kit_parse_bool and nbdkit_read_password .  See nbdkit-plugin(3) for in‐
132       formation about these functions.
133
134       On error these functions all raise Invalid_argument .  The actual error
135       is sent to the nbdkit error log and is not  available  from  the  OCaml
136       code.  It is usually best to let the exception escape.
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138
139
140       val parse_probability : string -> string -> float
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142
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145       val parse_bool : string -> bool
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149
150       val read_password : string -> string
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154
155       val stdio_safe : unit -> bool
156
157       Binding for nbdkit_stdio_safe .  Returns true if it is safe to interact
158       with stdin and stdout during the configuration phase.
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160
161
162       val realpath : string -> string
163
164       Binding for nbdkit_realpath .  Returns the canonical path from  a  path
165       parameter.
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167
168
169       val nanosleep : int -> int -> unit
170
171       Binding for nbdkit_nanosleep .  Sleeps for seconds and nanoseconds.
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173
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175       val export_name : unit -> string
176
177       Binding for nbdkit_export_name .  Returns the name of the export as re‐
178       quested by the client.
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180
181
182       val is_tls : unit -> bool
183
184       Binding for nbdkit_is_tls .  Returns true if the client  completed  TLS
185       authentication.
186
187
188
189       val shutdown : unit -> unit
190
191       Binding for nbdkit_shutdown .  Requests the server shut down.
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193
194
195       val disconnect : bool -> unit
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197       Binding for nbdkit_disconnect .  Requests disconnecting current client.
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199
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201       val debug : ('a, unit, string, unit) Stdlib.format4 -> 'a
202
203       Print a debug message when nbdkit is in verbose mode.
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206
207       val version : unit -> string
208
209       Return the version of nbdkit that the plugin was compiled with.
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211
212
213       val api_version : unit -> int
214
215       Return the nbdkit API version used by the plugin.
216
217       See NBDKIT_API_VERSION in nbdkit-plugin(3).
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219
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221       val peer_name : unit -> Unix.sockaddr
222
223       Binding for nbdkit_peer_name .
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225
226
227       val peer_pid : unit -> int64
228
229       Binding for nbdkit_peer_pid .
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231
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233       val peer_uid : unit -> int64
234
235       Binding for nbdkit_peer_uid .
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237
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239       val peer_gid : unit -> int64
240
241       Binding for nbdkit_peer_gid .
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243
244
245       val peer_security_context : unit -> string
246
247       Binding for nbdkit_peer_security_context .
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253OCamldoc                          2023-11-26                         NBDKit(3)