Bytesrw adapter for Eio
ocaml
codec
Refactor Pack to use bytesrw reader factories; add pread_reader
Pack files no longer require loading the entire file into a string.
Pack.t now stores a reader factory (int -> Reader.t) that creates
a bytesrw reader at any offset. of_string wraps strings for backward
compat; of_reader accepts any reader factory.
Added Bytesrw_eio.pread_reader: creates a bytesrw Reader from an
Eio file handle using pread for random-access reading. This is the
building block for file-backed pack reading (wiring pending — needs
switch lifetime design).
Pack.inflate replaced with Pack.inflate_reader that takes a Reader
directly instead of a string+offset.
+43
+28
src/bytesrw_eio.ml
+28
src/bytesrw_eio.ml
···
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@param slice_length
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Suggested slice length for upstream (default: 65536, which is
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{!Bytes.Slice.unix_io_buffer_size}) *)
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(** Create a [Bytes.Reader.t] from an Eio file at [offset].
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Uses pread for random-access reading without loading the whole file.
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@param slice_length Maximum bytes per slice (default: 65536).
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@param length Number of bytes to read (default: to end of file). *)
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let pread_reader ?(slice_length = Bytes.Slice.unix_io_buffer_size)
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?length ~offset (file : _ Eio.File.ro) : Bytes.Reader.t =
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let stat = Eio.File.stat file in
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let file_length = Optint.Int63.to_int stat.size in
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let total = match length with Some n -> n | None -> file_length - offset in
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let pos = ref 0 in
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let buf_size = Bytes.Slice.check_length slice_length in
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let buf = Bytes.create buf_size in
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let read () =
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if !pos >= total then Bytes.Slice.eod
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else
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let len = min buf_size (total - !pos) in
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let cs = Cstruct.create len in
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Eio.File.pread_exact file
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~file_offset:(Optint.Int63.of_int (offset + !pos))
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[ cs ];
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Cstruct.blit_to_bytes cs 0 buf 0 len;
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pos := !pos + len;
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Bytes.Slice.make buf ~first:0 ~length:len
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in
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Bytes.Reader.make ~slice_length read
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let bytes_writer_of_flow ?(slice_length = Bytes.Slice.unix_io_buffer_size)
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(flow : _ Eio.Flow.sink) : Bytes.Writer.t =
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let rec write slice =
+15
src/bytesrw_eio.mli
+15
src/bytesrw_eio.mli
···
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@param slice_length Maximum bytes per slice (default: 65536). *)
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(** {1 Random-access readers} *)
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val pread_reader :
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?slice_length:int ->
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?length:int ->
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offset:int ->
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_ Eio.File.ro ->
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Bytesrw.Bytes.Reader.t
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(** [pread_reader ~offset file] creates a reader from [file] starting at
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[offset] bytes. Reads via pread on demand — does not load the file into
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memory.
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@param slice_length Maximum bytes per slice (default: 65536).
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@param length Number of bytes to read (default: to end of file). *)
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(** {1 Writers} *)
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val bytes_writer_of_flow :