Source file pack.ml
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module Kind = struct
type t = Commit | Tag | Tree | Blob
let to_int = function Commit -> 0 | Tree -> 1 | Blob -> 2 | Tag -> 3
let to_bin = function
| Commit -> 0b001
| Tree -> 0b010
| Blob -> 0b011
| Tag -> 0b100
let pp ppf = function
| Commit -> Fmt.pf ppf "Commit"
| Tree -> Fmt.pf ppf "Tree"
| Blob -> Fmt.pf ppf "Blob"
| Tag -> Fmt.pf ppf "Tag"
end
module type ENTRY = sig
module Hash : S.HASH
type t
type source = From of Hash.t | None
val pp : t Fmt.t
val pp_source : source Fmt.t
val hash : string -> int
val make :
Hash.t
-> ?name:string
-> ?preferred:bool
-> ?delta:source
-> Kind.t
-> int64
-> t
val kind : t -> Kind.t
val preferred : t -> bool
val delta : t -> source
val length : t -> int64
val with_delta : t -> source -> t
val with_preferred : t -> bool -> t
val id : t -> Hash.t
val name : t -> string -> t
val compare : t -> t -> int
val topological_sort : t list -> t list
end
module Entry (Hash : S.HASH) = struct
type t =
{ hash_name: int
; hash_object: Hash.t
; name: string option
; kind: Kind.t
; preferred: bool
; delta: source
; length: int64 }
and source = From of Hash.t | None
let pp_source ppf = function
| From hash -> Fmt.pf ppf "Δ(%a)" Hash.pp hash
| None -> Fmt.string ppf "Τ"
let pp ppf {hash_name; hash_object; name; kind; preferred; delta; length} =
Fmt.pf ppf
"{ @[<hov>name = @[<hov>%x and %a@];@ hash = %a;@ kind = %a;@ preferred \
= %b;@ delta = %a;@ length = %Ld;@] }"
hash_name (Fmt.option Fmt.string) name (Fmt.hvbox Hash.pp) hash_object
(Fmt.hvbox Kind.pp) kind preferred (Fmt.hvbox pp_source) delta length
let hash name =
let res = ref 0 in
for i = 0 to String.length name - 1 do
if name.[i] <> ' ' then res := (!res lsr 2) + (Char.code name.[i] lsl 24)
done ;
!res
let hash name = hash (Filename.basename name)
let make :
Hash.t
-> ?name:string
-> ?preferred:bool
-> ?delta:source
-> Kind.t
-> int64
-> t =
fun hash_object ?name ?(preferred = false) ?(delta = None) kind length ->
let hash_name = Helper.Option.(value ~default:0 (name >>= hash)) in
{hash_name; hash_object; name; kind; preferred; delta; length}
let id {hash_object; _} = hash_object
let kind {kind; _} = kind
let preferred {preferred; _} = preferred
let delta {delta; _} = delta
let length {length; _} = length
let with_delta t delta = {t with delta}
let with_preferred t preferred = {t with preferred}
let name x name = {x with hash_name= hash name; name= Some name}
let compare a b =
let int_of_bool v = if v then 1 else 0 in
if Kind.to_int a.kind > Kind.to_int b.kind then -1
else if Kind.to_int a.kind < Kind.to_int b.kind then 1
else if a.hash_name > b.hash_name then -1
else if a.hash_name < b.hash_name then 1
else if int_of_bool a.preferred > int_of_bool b.preferred then -1
else if int_of_bool a.preferred < int_of_bool b.preferred then 1
else if a.length > b.length then -1
else if a.length < b.length then 1
else Stdlib.compare a b
let topological_sort lst =
let lst =
List.map
(function
| {delta= From hash; hash_object; _} as x ->
if Hash.equal hash hash_object then {x with delta= None} else x
| {delta= None; _} as x -> x)
lst
in
let edges, rest = List.partition (fun entry -> entry.delta = None) lst in
let deps hash =
try List.filter (fun e -> Hash.equal e.hash_object hash) lst
with Not_found -> []
in
let rec loop acc later rest progress =
match rest, later with
| [], [] -> List.rev acc
| [], later ->
if progress then loop acc [] later false
else
raise
(Invalid_argument "Entry.topological_sort: un-orderable list")
| ({delta= From hash; _} as x) :: r, later ->
let deps = deps hash in
let ensure =
List.for_all
(fun dep ->
List.exists
(fun x -> Hash.equal x.hash_object dep.hash_object)
acc )
deps
in
if ensure then loop (x :: acc) later r true
else loop acc (x :: later) r progress
| ({delta= None; _} as x) :: r, later -> loop (x :: acc) later r true
in
loop edges [] rest false
end
module Int32 = struct
include Int32
let ( && ) = Int32.logand
let ( >> ) = Int32.shift_right
end
module Int64 = struct
include Int64
let ( && ) = Int64.logand
let ( - ) = Int64.sub
let ( >> ) = Int64.shift_right
let ( / ) = Int64.div
end
module type H = sig
module Hash : S.HASH
type error
val pp_error : error Fmt.t
type t
type reference = Offset of int64 | Hash of Hash.t
val pp : t Fmt.t
val default : reference -> int -> int -> Duff.t list -> t
val refill : int -> int -> t -> t
val flush : int -> int -> t -> t
val finish : t -> t
val eval :
Cstruct.t
-> Cstruct.t
-> t
-> [`Await of t | `Flush of t | `End of t | `Error of t * error]
val used_in : t -> int
val used_out : t -> int
end
module Hunk (Hash : S.HASH) = struct
type error
let pp_error = Fmt.nop
type t =
{ o_off: int
; o_pos: int
; o_len: int
; i_off: int
; i_pos: int
; i_len: int
; i_abs: int
; write:
int
; reference: reference
; source_length: int
; target_length: int
; hunks: Duff.t list
; state: state }
and reference = Offset of int64 | Hash of Hash.t
and k = Cstruct.t -> t -> res
and state =
| List
| Hunk of k
| Insert of (Cstruct.t -> k)
| Copy of k
| Consume
| End
| Exception of error
and res = Error of t * error | Cont of t | Flush of t | Wait of t | Ok of t
let pp_state ppf = function
| Header _ -> Fmt.pf ppf "(Header #k)"
| List -> Fmt.pf ppf "List"
| Hunk _ -> Fmt.pf ppf "(Hunk #k)"
| Insert _ -> Fmt.pf ppf "(Insert #k)"
| Copy _ -> Fmt.pf ppf "(Copy #k)"
| End -> Fmt.pf ppf "End"
| Consume -> Fmt.pf ppf "Consume"
| Exception err -> Fmt.pf ppf "(Error %a)" (Fmt.hvbox pp_error) err
let pp_reference ppf = function
| Offset off -> Fmt.pf ppf "(Offset %Ld)" off
| Hash hash -> Fmt.pf ppf "(Hash %a)" Hash.pp hash
let pp ppf t =
Fmt.pf ppf
"{ @[<hov>o_off = %d;@ o_pos = %d;@ o_len = %d;@ i_off = %d;@ i_pos = \
%d;@ i_len = %d;@ i_abs = %d;@ write = %d;@ reference = %a;@ \
source_length = %d;@ target_length = %d;@ hunks = [ %a ];@ state = \
%a;@] }"
t.o_off t.o_pos t.o_len t.i_off t.i_pos t.i_len t.i_abs t.write
pp_reference t.reference t.source_length t.target_length
(Fmt.hvbox (Fmt.list ~sep:(Fmt.unit ";@ ") Duff.pp))
t.hunks (Fmt.hvbox pp_state) t.state
let ok t : res = Ok {t with state= End}
let await t : res = Wait t
let error t exn : res = Error ({t with state= Exception exn}, exn)
let rec put_byte ~ctor byte k dst t =
if t.o_len - t.o_pos > 0 then (
Cstruct.set_uint8 dst (t.o_off + t.o_pos) byte ;
k dst {t with o_pos= t.o_pos + 1; write= t.write + 1} )
else
Flush
{ t with
state= ctor (fun dst t -> (put_byte [@tailcall]) ~ctor byte k dst t)
}
module KHunk = struct let put_byte = put_byte ~ctor:(fun k -> Hunk k) end
module KInsert = struct
let rec put_raw (off, len) k src dst t =
if t.o_len - t.o_pos > len then (
Cstruct.blit src off dst (t.o_off + t.o_pos) len ;
k src dst {t with o_pos= t.o_pos + len; write= t.write + len} )
else if t.o_len - t.o_pos > 0 then
let rec loop rest src dst t =
let n = min (t.o_len - t.o_pos) rest in
Cstruct.blit src (off + (len - rest)) dst (t.o_off + t.o_pos) n ;
if rest - n = 0 then
k src dst {t with o_pos= t.o_pos + n; write= t.write + n}
else
Flush
{ t with
o_pos= t.o_pos + n
; write= t.write + n
; state= Insert (loop (rest - n)) }
in
loop len src dst t
else Flush {t with state= Insert (put_raw (off, len) k)}
end
module KCopy = struct
let rec put_byte ?(force = false) byte k dst t =
if byte <> 0 || force then
if t.o_len - t.o_pos > 0 then (
Cstruct.set_uint8 dst (t.o_off + t.o_pos) byte ;
k dst {t with o_pos= t.o_pos + 1; write= t.write + 1} )
else Flush {t with state= Copy (put_byte ~force byte k)}
else k dst t
end
let how_many_bytes n =
let rec aux acc n = if n = 0 then acc else aux (acc + 1) (n lsr 8) in
if n = 0 then 1 else aux 0 n
let rec insert res absolute_offset len src dst t =
if res = 0 then Cont {t with state= List}
else if
absolute_offset + (len - res) >= t.i_abs
&& absolute_offset + (len - res) < t.i_abs + t.i_len
then
let relative_offset = absolute_offset - t.i_abs in
let n = min res (t.i_len - (relative_offset + (len - res))) in
( KInsert.put_raw (t.i_off + relative_offset + (len - res), n)
@@ fun _ _ t ->
Cont
{ t with
state=
Insert (insert (res - n) absolute_offset len)
; i_pos= relative_offset + (len - res) + n } )
src dst t
else await {t with i_pos= t.i_len}
let copy (off, _) (len, _) dst t =
let o0 = off land 0xFF in
let o1 = (off land 0xFF00) lsr 8 in
let o2 = (off land 0xFF0000) lsr 16 in
let o3 = (off land 0xFF000000) lsr 24 in
let l0 = len land 0xFF in
let l1 = (len land 0xFF00) lsr 8 in
let l2 = (len land 0xFF0000) lsr 16 in
( KCopy.put_byte ~force:true o0
@@ KCopy.put_byte ~force:(o2 <> 0 || o3 <> 0) o1
@@ KCopy.put_byte ~force:(o3 <> 0) o2
@@ KCopy.put_byte o3
@@ KCopy.put_byte ~force:true l0
@@ KCopy.put_byte ~force:(l2 <> 0) l1
@@ KCopy.put_byte l2
@@ fun _ t -> Cont {t with state= List} )
dst t
let consume t = await {t with i_pos= t.i_len}
let list _ dst t =
match t.hunks with
| [] -> Cont {t with state= Consume}
| hunk :: r -> (
match hunk with
| Duff.Insert (off, len) ->
assert (len > 0 && len <= 0x7F) ;
let byte = len land 0x7F in
KHunk.put_byte byte
(fun _ t ->
Cont {t with state= Insert (insert len off len); hunks= r} )
dst t
| Duff.Copy (off, len) ->
let n_offset = how_many_bytes off in
let n_length = if len = 0x10000 then 1 else how_many_bytes len in
let o, fo =
match n_offset with
| 1 -> 0b0001, (false, false, false)
| 2 -> 0b0011, (true, false, false)
| 3 -> 0b0111, (true, true, false)
| 4 -> 0b1111, (true, true, true)
| _ -> assert false
in
let l, fl =
match n_length with
| 1 -> 0b001, (false, false)
| 2 -> 0b011, (true, false)
| 3 -> 0b111, (true, true)
| _ -> assert false
in
KHunk.put_byte
(0x80 lor (l lsl 4) lor o)
(copy (off, fo)
(if len = 0x10000 then 0, (false, false) else len, fl))
dst {t with hunks= r} )
let dst t =
( KHeader.length t.source_length
@@ KHeader.length t.target_length
@@ fun _ t -> Cont {t with state= List} )
dst t
let eval src dst t =
let eval0 t =
match t.state with
| Header k -> k dst t
| List -> list src dst t
| Hunk k -> k dst t
| Insert k -> k src dst t
| Copy k -> k dst t
| End -> ok t
| Consume -> consume t
| Exception exn -> error t exn
in
let rec loop t =
match eval0 t with
| Cont t -> loop t
| Flush t -> `Flush t
| Wait t -> `Await t
| Error (t, exn) -> `Error (t, exn)
| Ok t -> `End t
in
loop t
let default reference source_length target_length hunks =
{ o_off= 0
; o_pos= 0
; o_len= 0
; i_off= 0
; i_pos= 0
; i_len= 0
; i_abs= 0
; write= 0
; reference
; source_length
; target_length
; hunks
; state= Header header }
let flush off len t = {t with o_off= off; o_len= len; o_pos= 0}
let refill off len t =
{t with i_off= off; i_pos= 0; i_len= len; i_abs= t.i_abs + t.i_len}
let finish t = {t with state= End; i_pos= 0; i_len= 0; i_off= 0; i_abs= 0}
let used_in t = t.i_pos
let used_out t = t.o_pos
end
module type DELTA = sig
module Hash : S.HASH
module Entry : ENTRY with module Hash := Hash
type t = {mutable delta: delta}
and delta =
| Z
| S of
{ length: int
; depth: int
; hunks: Duff.t list
; src: t
; src_length: int64
; src_hash: Hash.t }
type error = Invalid_hash of Hash.t
val pp_error : error Fmt.t
val deltas :
?memory:bool
-> Entry.t list
-> (Hash.t -> Cstruct.t option Lwt.t)
-> (Entry.t -> bool)
-> int
-> int
-> ((Entry.t * t) list, error) result Lwt.t
end
module Delta (Hash : S.HASH) (Entry : ENTRY with module Hash := Hash) = struct
type t = {mutable delta: delta}
and delta =
| Z
| S of
{ length: int
; depth: int
; hunks: Duff.t list
; src: t
; src_length:
int64
; src_hash: Hash.t }
module WeightByMemory = struct
type nonrec t = t * Cstruct.t * Duff.Default.Index.t
let weight (_, raw, rabin) =
1 + Cstruct.len raw + 1 + Duff.Default.Index.memory_size rabin
end
module WeightByElement = struct
type nonrec t = t * Cstruct.t * Duff.Default.Index.t
let weight _ = 1
end
module type WINDOW =
Lru.F.S
with type k = Entry.t
and type v = t * Cstruct.t * Duff.Default.Index.t
let rec _pp_delta ppf = function
| Z -> Fmt.string ppf "Τ"
| S {length; depth; hunks; src; src_length; _} ->
Fmt.pf ppf
"(Δ { @[<hov>length = %d;@ depth = %d;@ hunks = [ %a ];@ src = \
%a;@ src_length = %Ld;@] }"
length depth
(Fmt.hvbox (Fmt.list ~sep:(Fmt.unit ";@ ") Duff.pp))
hunks (Fmt.hvbox _pp) src src_length
and _pp ppf {delta} =
Fmt.pf ppf "{ @[<hov>delta = @[<hov>%a@];@] }" (Fmt.hvbox _pp_delta) delta
type error = Invalid_hash of Hash.t
let pp_error ppf (Invalid_hash hash) =
Fmt.pf ppf
"Got an invalid (non-existing) hash when we apply the delta-ification: %a"
Hash.pp hash
let depth = function {delta= S {depth; _}} -> depth | {delta= Z} -> 0
let size_of_variable_length vl =
let rec loop acc = function 0 -> acc | n -> loop (acc + 1) (n lsr 7) in
loop 1 (vl lsr 7)
let how_many_bytes n =
let rec aux acc n = if n = 0 then acc else aux (acc + 1) (n lsr 8) in
if n = 0 then 1 else aux 0 n
let length src_len trg_len hunks =
size_of_variable_length src_len
+ size_of_variable_length trg_len
+ List.fold_left
(fun acc -> function Duff.Insert (_, len) -> 1 + len + acc
| Duff.Copy (off, len) ->
1
+ how_many_bytes off
+ (if len = 0x10000 then 1 else how_many_bytes len)
+ acc )
0 hunks
let only_insert =
List.for_all (function Duff.Insert _ -> true | Duff.Copy _ -> false)
let delta : type window.
window
-> (module WINDOW with type t = window)
-> int
-> Entry.t
-> Cstruct.t
-> t
-> (Entry.t * Duff.t list * int) option =
fun window window_pack max trg_entry trg_raw trg ->
let limit src =
match trg.delta with
| S {length; src; _} ->
length * (max - depth src) / (max - (depth trg + 1))
| Z ->
((Int64.to_int (Entry.length trg_entry) / 2) - 20)
* (max - depth src)
/ (max - 1)
in
let choose a b =
match a, b with
| None, None -> None
| Some a, None ->
Some a
| None, Some (a, hunks_a, len_a) ->
if not (only_insert hunks_a) then Some (a, hunks_a, len_a) else None
| Some (a, hunks_a, len_a), Some (b, hunks_b, len_b) ->
if len_a < len_b then Some (a, hunks_a, len_a)
else Some (b, hunks_b, len_b)
in
let apply src_entry (src, src_raw, rabin) best =
let diff =
if Entry.length src_entry < Entry.length trg_entry then
Int64.to_int
(Int64.sub (Entry.length trg_entry) (Entry.length src_entry))
else 0
in
if
Entry.kind src_entry <> Entry.kind trg_entry
|| depth src = max
|| limit src = 0
|| limit src <= diff
|| (Entry.length trg_entry < Int64.(Entry.length src_entry / 32L))
|| Hash.equal (Entry.id src_entry) (Entry.id trg_entry)
then best
else
let hunks = Duff.Default.delta rabin trg_raw in
let length =
length (Cstruct.len src_raw) (Cstruct.len trg_raw) hunks
in
choose best (Some (src_entry, hunks, length))
in
let module Window = (val window_pack) in
if (not (Entry.preferred trg_entry)) && depth trg < max then
Window.fold apply None window
else None
let ok v = Ok v
let sort _ lst =
let edges, rest =
List.partition
(function _, {delta= Z} -> true | _, {delta= S _} -> false)
lst
in
let deps hash =
try List.filter (fun (e, _) -> Hash.equal (Entry.id e) hash) lst
with Not_found -> []
in
let rec loop acc later rest progress =
match rest, later with
| [], [] -> List.rev acc
| [], later ->
if progress then loop acc [] later false
else raise (Invalid_argument "Delta.sort: un-orderable list")
| ((_, {delta= Z}) as x) :: r, later -> loop (x :: acc) later r true
| ((_, {delta= S {src_hash; _}}) as x) :: r, later ->
let deps = deps src_hash in
let ensure =
List.for_all
(fun (e, _) ->
List.exists
(fun (x, _) -> Hash.equal (Entry.id x) (Entry.id e))
acc )
deps
in
if ensure then loop (x :: acc) later r true
else loop acc (x :: later) r progress
in
loop edges [] rest false
exception Uncaught_hash of Hash.t
module MemoryCache = Lru.F.Make (Entry) (WeightByMemory)
module ElementCache = Lru.F.Make (Entry) (WeightByElement)
let deltas ?(memory = false) entries get tag window max =
let to_delta e =
match Entry.delta e, Entry.preferred e with
| Entry.None, false -> Entry.length e >= 50L
| (Entry.From _ | Entry.None), _ -> false
in
let tries =
List.filter to_delta entries |> List.stable_sort Entry.compare
in
let untries =
List.filter (fun x -> not (to_delta x)) entries |> Entry.topological_sort
in
let window_pack =
if memory then (module MemoryCache : WINDOW)
else (module ElementCache : WINDOW)
in
let module Window = (val window_pack) in
let window_pack = (module Window : WINDOW with type t = Window.t) in
let window = Window.empty window in
let normal = Hashtbl.create (List.length tries) in
let open Lwt.Infix in
let normalize lst =
Lwt_list.map_p
(fun trg_entry ->
match Entry.delta trg_entry with
| Entry.None -> Lwt.return (trg_entry, {delta= Z})
| Entry.From hash -> (
let src =
try Hashtbl.find normal hash with Not_found -> {delta= Z}
in
get hash
>>= fun a ->
get (Entry.id trg_entry)
>>= fun b ->
match a, b with
| Some src_raw, Some trg_raw ->
let rabin = Duff.Default.Index.make ~copy:false src_raw in
let hunks = Duff.Default.delta rabin trg_raw in
let length =
length (Cstruct.len src_raw) (Cstruct.len trg_raw) hunks
in
let depth = depth src + 1 in
let base =
{ delta=
S
{ length
; depth
; hunks
; src
; src_length= Int64.of_int (Cstruct.len src_raw)
; src_hash= hash } }
in
Hashtbl.add normal (Entry.id trg_entry) base ;
Lwt.return (trg_entry, base)
| None, Some _ -> raise (Uncaught_hash hash)
| Some _, None -> raise (Uncaught_hash (Entry.id trg_entry))
| None, None -> assert false ) )
lst
in
Lwt.try_bind
(fun () ->
Lwt_list.fold_left_s
(fun (window, acc) entry ->
get (Entry.id entry)
>>= function
| None -> raise (Uncaught_hash (Entry.id entry))
| Some raw -> (
let base = {delta= Z} in
let rabin = Duff.Default.Index.make ~copy:false raw in
let window = Window.add entry (base, raw, rabin) window in
let window = Window.trim window in
match delta window window_pack max entry raw base with
| None -> Lwt.return (window, (entry, base) :: acc)
| Some (src_entry, hunks, length) -> (
match Window.find src_entry window with
| Some (src, _, _) ->
let window = Window.promote src_entry window in
let depth = depth src + 1 in
base.delta
<- S
{ length
; depth
; hunks
; src
; src_length= Entry.length src_entry
; src_hash= Entry.id src_entry } ;
Hashtbl.add normal (Entry.id entry) base ;
Lwt.return
( window
, ( Entry.with_delta entry Entry.(From (id src_entry))
, base )
:: acc )
| None -> Lwt.return (window, (entry, base) :: acc) ) ) )
(window, []) tries )
(fun (_, tries) ->
Lwt.try_bind
(fun () -> normalize untries)
(fun untries ->
List.append tries untries |> sort tag |> ok |> Lwt.return )
(function
| Uncaught_hash hash -> Error (Invalid_hash hash) |> Lwt.return
| exn -> Lwt.fail exn) )
(function
| Uncaught_hash hash -> Error (Invalid_hash hash) |> Lwt.return
| exn -> Lwt.fail exn)
end
module type P = sig
module Hash : S.HASH
module Deflate : S.DEFLATE
module Entry : ENTRY with module Hash := Hash
module Delta : DELTA with module Hash := Hash and module Entry := Entry
module Hunk : H with module Hash := Hash
type error = Deflate_error of Deflate.error | Invalid_hash of Hash.t
val pp_error : error Fmt.t
type t
val used_out : t -> int
val used_in : t -> int
val flush : int -> int -> t -> t
val refill : int -> int -> t -> t
val finish : t -> t
val expect : t -> Hash.t
val idx : t -> (Checkseum.Crc32.t * int64) Hash.Map.t
val default : Cstruct.t -> (Entry.t * Delta.t) list -> t
val eval :
Cstruct.t
-> Cstruct.t
-> t
-> [`Flush of t | `Await of t | `End of t * Hash.t | `Error of t * error]
end
module Pack
(Hash : S.HASH)
(Deflate : S.DEFLATE)
(Entry : ENTRY with module Hash := Hash)
(Delta : DELTA with module Hash := Hash and module Entry := Entry)
(Hunk : H with module Hash := Hash) =
struct
type error = Deflate_error of Deflate.error | Invalid_hash of Hash.t
let pp_error ppf = function
| Deflate_error err ->
Fmt.pf ppf "Got a deflate error: %a" Deflate.pp_error err
| Invalid_hash hash -> Fmt.pf ppf "Invalid hash: %a" Hash.pp hash
type t =
{ o_off: int
; o_pos: int
; o_len: int
; i_off: int
; i_pos: int
; i_len: int
; write: int64
; map: (Checkseum.Crc32.t * int64) Hash.Map.t
; hash: Hash.ctx
; h_tmp: Cstruct.t
; state: state }
and k = Cstruct.t -> t -> res
and state =
| Object of k
| WriteK of k
| WriteZ of
{ x: Entry.t
; r: (Entry.t * Delta.t) list
; crc: Checkseum.Crc32.t
; off: int64
; ui: int
; z: Deflate.t }
| WriteH of
{ x: Entry.t * Delta.t
; r: (Entry.t * Delta.t) list
; crc: Checkseum.Crc32.t
; off: int64
; ui: int
; h: Hunk.t
; z: Deflate.t }
| Save of
{ x: Entry.t
; r: (Entry.t * Delta.t) list
; crc: Checkseum.Crc32.t
; off: int64 }
| Hash of k
| End of Hash.t
| Exception of error
and res =
| Flush of t
| Wait of t
| Error of t * error
| Cont of t
| Ok of t * Hash.t
and kind = KindOffset | KindHash | KindRaw
let flush dst t =
let hash = Hash.feed_cstruct t.hash (Cstruct.sub dst t.o_off t.o_pos) in
Flush {t with hash}
let await t : res = Wait t
let error t exn : res = Error ({t with state= Exception exn}, exn)
let ok t hash : res = Ok ({t with state= End hash}, hash)
let rec put_byte ~ctor byte k dst t =
if t.o_len - t.o_pos > 0 then (
Cstruct.set_uint8 dst (t.o_off + t.o_pos) byte ;
k dst {t with o_pos= t.o_pos + 1; write= Int64.add t.write 1L} )
else
flush dst {t with state= ctor (fun dst t -> put_byte ~ctor byte k dst t)}
module KWriteK = struct
let put_byte = put_byte ~ctor:(fun k -> WriteK k)
let = Bytes.create 10
let kind len crc k dst t =
let byt = ref ((kind lsl 4) lor Int64.(to_int (len && 15L))) in
let len = ref Int64.(len >> 4) in
let pos = ref 0 in
while !len <> 0L do
Bytes.set tmp_header !pos (Char.unsafe_chr (!byt lor 0x80)) ;
(byt := Int64.(to_int (!len && 0x7FL))) ;
(len := Int64.(!len >> 7)) ;
pos := !pos + 1
done ;
Bytes.set tmp_header !pos (Char.unsafe_chr !byt) ;
pos := !pos + 1 ;
let rec loop idx crc dst t =
if idx < !pos then
let byte = Char.code (Bytes.get tmp_header idx) in
let crc = Crc32.digestc crc byte in
put_byte byte (loop (idx + 1) crc) dst t
else k crc dst t
in
loop 0 crc dst t
let tmp_offset = Bytes.create 10
let offset n crc k dst t =
let pos = ref 9 in
let off = ref n in
Bytes.set tmp_offset !pos (Char.chr Int64.(to_int (!off && 127L))) ;
while Int64.(!off >> 7) <> 0L do
(off := Int64.(!off >> 7)) ;
pos := !pos - 1 ;
Bytes.set tmp_offset !pos
(Char.chr (128 lor Int64.(to_int ((!off - 1L) && 127L)))) ;
off := Int64.sub !off 1L
done ;
let rec loop idx crc dst t =
if idx = 10 then k crc dst t
else
let byte = Char.code (Bytes.get tmp_offset idx) in
let crc = Crc32.digestc crc byte in
put_byte byte (loop (idx + 1) crc) dst t
in
loop !pos crc dst t
let hash hash crc k dst t =
if t.o_len - t.o_pos >= Hash.digest_size then (
let crc = Crc32.digests crc hash in
Cstruct.blit_from_string hash 0 dst (t.o_off + t.o_pos)
Hash.digest_size ;
k crc dst
{ t with
o_pos= t.o_pos + Hash.digest_size
; write= Int64.add t.write (Int64.of_int Hash.digest_size) } )
else
let rec loop rest crc dst t =
if rest = 0 then k crc dst t
else
let n = min rest (t.o_len - t.o_pos) in
if n = 0 then flush dst {t with state= Hash (loop rest crc)}
else
let crc =
Crc32.digests crc ~off:(Hash.digest_size - rest) ~len:n hash
in
Cstruct.blit_from_string hash (Hash.digest_size - rest) dst
(t.o_off + t.o_pos) n ;
loop (rest - n) crc dst
{ t with
o_pos= t.o_pos + n; write= Int64.add t.write (Int64.of_int n)
}
in
loop Hash.digest_size crc dst t
end
module KHash = struct
let put_hash hash k dst t =
if t.o_len - t.o_pos >= Hash.digest_size then (
Cstruct.blit_from_string hash 0 dst (t.o_off + t.o_pos)
Hash.digest_size ;
k dst
{ t with
o_pos= t.o_pos + Hash.digest_size
; write= Int64.add t.write (Int64.of_int Hash.digest_size) } )
else
let rec loop rest dst t =
if rest = 0 then k dst t
else
let n = min rest (t.o_len - t.o_pos) in
if n = 0 then Flush {t with state= Hash (loop rest)}
else (
Cstruct.blit_from_string hash (Hash.digest_size - rest) dst
(t.o_off + t.o_pos) n ;
Flush
{ t with
state= Hash (loop (rest - n))
; o_pos= t.o_pos + n
; write= Int64.add t.write (Int64.of_int n) } )
in
loop Hash.digest_size dst t
end
let hash dst t =
let ctx = Hash.feed_cstruct t.hash (Cstruct.sub dst t.o_off t.o_pos) in
let hash = Hash.get ctx in
KHash.put_hash (Hash.to_raw_string hash)
(fun _ t -> ok t hash)
dst {t with hash= ctx}
let writek kind entry entry_delta rest dst t =
match kind, entry_delta with
| KindRaw, {Delta.delta= Delta.Z} ->
let abs_off = t.write in
( KWriteK.header
(Kind.to_bin (Entry.kind entry))
(Entry.length entry) Crc32.default
@@ fun crc _ t ->
let z = Deflate.default 4 in
let z = Deflate.flush (t.o_off + t.o_pos) (t.o_len - t.o_pos) z in
Cont
{ t with
state= WriteZ {x= entry; r= rest; crc; off= abs_off; ui= 0; z}
; i_off= 0
; i_pos= 0
; i_len= 0 } )
dst t
| KindHash, {Delta.delta= Delta.S {length; hunks; src_length; src_hash; _}}
->
let trg_length = Entry.length entry in
let abs_off = t.write in
let h =
Hunk.flush 0 (Cstruct.len t.h_tmp)
@@ Hunk.default (Hunk.Hash src_hash) (Int64.to_int src_length)
(Int64.to_int trg_length) hunks
in
( KWriteK.header 0b111 (Int64.of_int length) Crc32.default
@@ fun crc ->
KWriteK.hash (Hash.to_raw_string src_hash) crc
@@ fun crc _ t ->
let z = Deflate.default 4 in
let z = Deflate.flush (t.o_off + t.o_pos) (t.o_len - t.o_pos) z in
Cont
{ t with
state=
WriteH
{x= entry, entry_delta; r= rest; crc; off= abs_off; ui= 0; h; z}
; i_off= 0
; i_len= 0
; i_pos= 0 } )
dst t
| ( KindOffset
, {Delta.delta= Delta.S {length; hunks; src_length; src_hash; _}} ) ->
let _, src_off = Hash.Map.find src_hash t.map in
let trg_length = Entry.length entry in
let abs_off = t.write in
let rel_off = Int64.sub abs_off src_off in
let h =
Hunk.flush 0 (Cstruct.len t.h_tmp)
@@ Hunk.default (Hunk.Offset rel_off) (Int64.to_int src_length)
(Int64.to_int trg_length) hunks
in
( KWriteK.header 0b110 (Int64.of_int length) Crc32.default
@@ fun crc ->
KWriteK.offset rel_off crc
@@ fun crc _ t ->
let z = Deflate.default 4 in
let z = Deflate.flush (t.o_off + t.o_pos) (t.o_len - t.o_pos) z in
Cont
{ t with
state=
WriteH
{x= entry, entry_delta; r= rest; crc; off= abs_off; ui= 0; h; z}
; i_off= 0
; i_len= 0
; i_pos= 0 } )
dst t
| (KindRaw | KindHash | KindOffset), {Delta.delta= Delta.S _ | Delta.Z; _}
->
assert false
let writez src dst t x r crc off used_in z =
match Deflate.eval ~src ~dst z with
| `Await z ->
await
{ t with
state= WriteZ {x; r; crc; off; ui= used_in; z}
; i_pos= Deflate.used_in z }
| `Flush z ->
let crc =
Crc32.digest ~off:(t.o_off + t.o_pos) ~len:(Deflate.used_out z) crc
dst
in
flush dst
{ t with
state= WriteZ {x; r; crc; off; ui= Deflate.used_in z; z}
; o_pos= t.o_pos + Deflate.used_out z
; i_pos= Deflate.used_in z
; write= Int64.add t.write (Int64.of_int (Deflate.used_out z)) }
| `End z ->
let crc =
Crc32.digest ~off:(t.o_off + t.o_pos) ~len:(Deflate.used_out z) crc
dst
in
Cont
{ t with
state= Save {x; r; crc; off}
; o_pos= t.o_pos + Deflate.used_out z
; i_pos= Deflate.used_in z
; write= Int64.add t.write (Int64.of_int (Deflate.used_out z)) }
| `Error (_, exn) -> error t (Deflate_error exn)
let writeh src dst t ((entry, _) as x) r crc off used_in h z =
match Deflate.eval ~src:t.h_tmp ~dst z with
| `Await z -> (
match Hunk.eval src t.h_tmp h with
| `Await h ->
await
{ t with
state= WriteH {x; r; crc; off; ui= 0; z; h}
; i_pos= Hunk.used_in h }
| `Flush h ->
let used_in' = used_in + Deflate.used_in z in
let z, h, ui =
if used_in' = Hunk.used_out h then
Deflate.no_flush 0 0 z, Hunk.flush 0 (Cstruct.len t.h_tmp) h, 0
else
( Deflate.no_flush used_in' (Hunk.used_out h - used_in') z
, h
, used_in' )
in
Cont
{ t with
state= WriteH {x; r; crc; off; ui; h; z}; i_pos= Hunk.used_in h
}
| `End h ->
let used_in' = used_in + Deflate.used_in z in
let z, h, ui =
if used_in' = Hunk.used_out h then Deflate.finish z, h, used_in'
else
( Deflate.no_flush used_in' (Hunk.used_out h - used_in') z
, h
, used_in' )
in
Cont
{ t with
state= WriteH {x; r; crc; off; ui; h; z}; i_pos= Hunk.used_in h
}
| `Error (_, _) -> assert false )
| `Flush z ->
let crc =
Crc32.digest ~off:(t.o_off + t.o_pos) ~len:(Deflate.used_out z) crc
dst
in
let used_in' = used_in + Deflate.used_in z in
flush dst
{ t with
state= WriteH {x; r; crc; off; ui= used_in'; h; z}
; i_pos= Hunk.used_in h
; o_pos= t.o_pos + Deflate.used_out z
; write= Int64.add t.write (Int64.of_int (Deflate.used_out z)) }
| `End z ->
let crc =
Crc32.digest ~off:(t.o_off + t.o_pos) ~len:(Deflate.used_out z) crc
dst
in
Cont
{ t with
state= Save {x= entry; r; crc; off}
; o_pos= t.o_pos + Deflate.used_out z
; i_pos= 0
; i_len= 0
; i_off= 0
; write= Int64.add t.write (Int64.of_int (Deflate.used_out z)) }
| `Error (_, exn) -> error t (Deflate_error exn)
let iter lst _ t =
match lst with
| [] -> Cont {t with state= Hash hash}
| (entry, delta) :: r -> (
match Entry.delta entry, delta with
| Entry.From src_hash, {Delta.delta= Delta.S _} ->
if Hash.Map.mem src_hash t.map then
Cont {t with state= WriteK (writek KindOffset entry delta r)}
else Cont {t with state= WriteK (writek KindHash entry delta r)}
| Entry.None, {Delta.delta= Delta.Z} ->
Cont {t with state= WriteK (writek KindRaw entry delta r)}
| (Entry.None | Entry.From _), {Delta.delta= Delta.S _ | Delta.Z} ->
error t (Invalid_hash (Entry.id entry)) )
let save _ t x r crc off =
Cont
{ t with
state= Object (iter r); map= Hash.Map.add (Entry.id x) (crc, off) t.map
}
let number lst dst t =
KHeader.put_u32
(Int32.of_int (List.length lst))
(fun _ t -> Cont {t with state= Object (iter lst)})
dst t
let version lst dst t =
KHeader.put_u32 2l
(fun _ t -> Cont {t with state= Header (number lst)})
dst t
let lst dst t =
( KHeader.put_byte (Char.code 'P')
@@ KHeader.put_byte (Char.code 'A')
@@ KHeader.put_byte (Char.code 'C')
@@ KHeader.put_byte (Char.code 'K')
@@ fun _ t -> Cont {t with state= Header (version lst)} )
dst t
let used_out t = t.o_pos
let idx t = t.map
let eval src dst t =
let eval0 t =
match t.state with
| Header k -> k dst t
| Object k -> k dst t
| WriteK k -> k dst t
| WriteZ {x; r; crc; off; ui; z} -> writez src dst t x r crc off ui z
| WriteH {x; r; crc; off; ui; h; z} ->
writeh src dst t x r crc off ui h z
| Save {x; r; crc; off} -> save dst t x r crc off
| Exception exn -> error t exn
| Hash k -> k dst t
| End hash -> Ok (t, hash)
in
let rec loop t =
match eval0 t with
| Cont t -> loop t
| Flush t -> `Flush t
| Wait t -> `Await t
| Ok (t, hash) -> `End (t, hash)
| Error (t, exn) -> `Error (t, exn)
in
loop t
let flush offset len t =
if t.o_len - t.o_pos = 0 then
match t.state with
| WriteZ {x; r; crc; off; ui; z} ->
{ t with
o_off= offset
; o_len= len
; o_pos= 0
; state= WriteZ {x; r; crc; off; ui; z= Deflate.flush offset len z}
}
| WriteH {x; r; crc; off; ui; h; z} ->
{ t with
o_off= offset
; o_len= len
; o_pos= 0
; state= WriteH {x; r; crc; off; ui; h; z= Deflate.flush offset len z}
}
| Header _ | Object _ | WriteK _ | Save _ | Hash _ | End _ | Exception _
->
{t with o_off= offset; o_len= len; o_pos= 0}
else
match t.state with
| End _ -> {t with o_off= offset; o_len= len; o_pos= 0}
| Header _ | Object _ | WriteK _ | WriteZ _ | WriteH _ | Save _
|Hash _ | Exception _ ->
raise
(Invalid_argument
(Fmt.strf
"PACKEncoder.flush: you lost something (pos: %d, len: %d)"
t.o_pos t.o_len))
let expect t =
match t.state with
| WriteH {x= entry, _; _} -> Entry.id entry
| WriteZ {x= entry; _} -> Entry.id entry
| Header _ | Object _ | WriteK _ | Save _ | Hash _ | End _ | Exception _ ->
raise (Invalid_argument "PACKEncoder.expecti: bad state")
let refill offset len t =
if t.i_len - t.i_pos = 0 then
match t.state with
| WriteZ {x; r; crc; off; ui; z} ->
{ t with
i_off= offset
; i_len= len
; i_pos= 0
; state= WriteZ {x; r; crc; off; ui; z= Deflate.no_flush offset len z}
}
| WriteH {x; r; crc; off; ui; z; h} ->
{ t with
i_off= offset
; i_len= len
; i_pos= 0
; state= WriteH {x; r; crc; off; ui; z; h= Hunk.refill offset len h}
}
| Header _ | Object _ | WriteK _ | Save _ | Hash _ | End _ | Exception _
->
{t with i_off= offset; i_len= len; i_pos= 0}
else
raise
(Invalid_argument
(Fmt.strf
"PACKEncoder.refill: you lost something (pos: %d, len: %d)"
t.i_pos t.i_len))
let finish t =
if t.i_len - t.i_pos = 0 then
match t.state with
| WriteZ {x; r; crc; off; ui; z} ->
{t with state= WriteZ {x; r; crc; off; ui; z= Deflate.finish z}}
| WriteH {x; r; crc; off; ui; z; h} ->
{t with state= WriteH {x; r; crc; off; ui; z; h= Hunk.finish h}}
| Header _ | Object _ | WriteK _ | Save _ | Hash _ | End _ | Exception _
->
t
else
raise
(Invalid_argument
(Fmt.strf
"PACKEncoder.finish: you lost something (pos: %d, len: %d)"
t.i_pos t.i_len))
let used_in t =
match t.state with
| WriteZ {z; _} -> Deflate.used_in z
| WriteH {h; _} -> Hunk.used_in h
| Header _ | Object _ | WriteK _ | Save _ | Hash _ | End _ | Exception _ ->
raise (Invalid_argument "PACKEncoder.used_in: bad state")
let default h_tmp objects =
{ o_off= 0
; o_pos= 0
; o_len= 0
; i_off= 0
; i_pos= 0
; i_len= 0
; write= 0L
; map= Hash.Map.empty
; h_tmp
; hash= Hash.init ()
; state= Header (header objects) }
end
module Stream (Hash : S.HASH) (Deflate : S.DEFLATE) = struct
module Entry = Entry (Hash)
module Delta = Delta (Hash) (Entry)
module Hunk = Hunk (Hash)
module Pack = Pack (Hash) (Deflate) (Entry) (Delta) (Hunk)
include Pack
end