Revision 2588d66c3354660426c313e268d0994b731367f9 authored by Jishnu Bhattacharya on 12 April 2024, 19:43:23 UTC, committed by Jishnu Bhattacharya on 12 April 2024, 19:43:23 UTC
1 parent 1ae41a2
filesystem.jl
# This file is a part of Julia. License is MIT: https://julialang.org/license
## File Operations (Libuv-based) ##
module Filesystem
"""
JL_O_APPEND
JL_O_ASYNC
JL_O_CLOEXEC
JL_O_CREAT
JL_O_DIRECT
JL_O_DIRECTORY
JL_O_DSYNC
JL_O_EXCL
JL_O_FSYNC
JL_O_LARGEFILE
JL_O_NDELAY
JL_O_NOATIME
JL_O_NOCTTY
JL_O_NOFOLLOW
JL_O_NONBLOCK
JL_O_PATH
JL_O_RANDOM
JL_O_RDONLY
JL_O_RDWR
JL_O_RSYNC
JL_O_SEQUENTIAL
JL_O_SHORT_LIVED
JL_O_SYNC
JL_O_TEMPORARY
JL_O_TMPFILE
JL_O_TRUNC
JL_O_WRONLY
Enum constant for the `open` syscall, where `JL_O_*` corresponds to the `O_*` constant.
See [the libuv docs](https://docs.libuv.org/en/v1.x/fs.html#file-open-constants) for more details.
"""
(:JL_O_APPEND, :JL_O_ASYNC, :JL_O_CLOEXEC, :JL_O_CREAT, :JL_O_DIRECT,
:JL_O_DIRECTORY, :JL_O_DSYNC, :JL_O_EXCL, :JL_O_FSYNC, :JL_O_LARGEFILE,
:JL_O_NOATIME, :JL_O_NOCTTY, :JL_O_NDELAY, :JL_O_NOFOLLOW, :JL_O_NONBLOCK,
:JL_O_PATH, :JL_O_RANDOM, :JL_O_RDONLY, :JL_O_RDWR, :JL_O_RSYNC,
:JL_O_SEQUENTIAL, :JL_O_SHORT_LIVED, :JL_O_SYNC, :JL_O_TEMPORARY,
:JL_O_TMPFILE, :JL_O_TRUNC, :JL_O_WRONLY)
const S_IFDIR = 0o040000 # directory
const S_IFCHR = 0o020000 # character device
const S_IFBLK = 0o060000 # block device
const S_IFREG = 0o100000 # regular file
const S_IFIFO = 0o010000 # fifo (named pipe)
const S_IFLNK = 0o120000 # symbolic link
const S_IFSOCK = 0o140000 # socket file
const S_IFMT = 0o170000
const S_ISUID = 0o4000 # set UID bit
const S_ISGID = 0o2000 # set GID bit
const S_ENFMT = S_ISGID # file locking enforcement
const S_ISVTX = 0o1000 # sticky bit
const S_IRUSR = 0o0400 # read by owner
const S_IWUSR = 0o0200 # write by owner
const S_IXUSR = 0o0100 # execute by owner
const S_IRWXU = 0o0700 # mask for owner permissions
const S_IRGRP = 0o0040 # read by group
const S_IWGRP = 0o0020 # write by group
const S_IXGRP = 0o0010 # execute by group
const S_IRWXG = 0o0070 # mask for group permissions
const S_IROTH = 0o0004 # read by other
const S_IWOTH = 0o0002 # write by other
const S_IXOTH = 0o0001 # execute by other
const S_IRWXO = 0o0007 # mask for other permissions
"""
S_IRUSR
S_IWUSR
S_IXUSR
S_IRGRP
S_IWGRP
S_IXGRP
S_IROTH
S_IWOTH
S_IXOTH
Constants for file access permission bits.
The general structure is `S_I[permission][class]`
where `permission` is `R` for read, `W` for write, and `X` for execute,
and `class` is `USR` for user/owner, `GRP` for group, and `OTH` for other.
"""
(:S_IRUSR, :S_IWUSR, :S_IXUSR, :S_IRGRP, :S_IWGRP, :S_IXGRP, :S_IROTH, :S_IWOTH, :S_IXOTH)
"""
S_IRWXU
S_IRWXG
S_IRWXO
Constants for file access permission masks, i.e. the combination of read, write,
and execute permissions for a class.
The general structure is `S_IRWX[class]`
where `class` is `U` for user/owner, `G` for group, and `O` for other.
"""
(:S_IRWXU, :S_IRWXG, :S_IRWXO)
export File,
StatStruct,
# open,
futime,
write,
JL_O_WRONLY,
JL_O_RDONLY,
JL_O_RDWR,
JL_O_APPEND,
JL_O_CREAT,
JL_O_EXCL,
JL_O_TRUNC,
JL_O_TEMPORARY,
JL_O_SHORT_LIVED,
JL_O_SEQUENTIAL,
JL_O_RANDOM,
JL_O_NOCTTY,
JL_O_NONBLOCK,
JL_O_NDELAY,
JL_O_SYNC,
JL_O_FSYNC,
JL_O_ASYNC,
JL_O_LARGEFILE,
JL_O_DIRECTORY,
JL_O_NOFOLLOW,
JL_O_CLOEXEC,
JL_O_DIRECT,
JL_O_NOATIME,
JL_O_PATH,
JL_O_TMPFILE,
JL_O_DSYNC,
JL_O_RSYNC,
S_IRUSR, S_IWUSR, S_IXUSR, S_IRWXU,
S_IRGRP, S_IWGRP, S_IXGRP, S_IRWXG,
S_IROTH, S_IWOTH, S_IXOTH, S_IRWXO
import .Base:
IOError, _UVError, _sizeof_uv_fs, check_open, close, eof, eventloop, fd, isopen,
bytesavailable, position, read, read!, readavailable, seek, seekend, show,
skip, stat, unsafe_read, unsafe_write, write, transcode, uv_error,
setup_stdio, rawhandle, OS_HANDLE, INVALID_OS_HANDLE, windowserror, filesize,
isexecutable, isreadable, iswritable
import .Base.RefValue
if Sys.iswindows()
import .Base: cwstring
end
# Average buffer size including null terminator for several filesystem operations.
# On Windows we use the MAX_PATH = 260 value on Win32.
const AVG_PATH = Sys.iswindows() ? 260 : 512
# helper function to clean up libuv request
uv_fs_req_cleanup(req) = ccall(:uv_fs_req_cleanup, Cvoid, (Ptr{Cvoid},), req)
include("path.jl")
include("stat.jl")
include("file.jl")
include(string(length(Core.ARGS) >= 2 ? Core.ARGS[2] : "", "file_constants.jl")) # include($BUILDROOT/base/file_constants.jl)
## Operations with File (fd) objects ##
abstract type AbstractFile <: IO end
mutable struct File <: AbstractFile
open::Bool
handle::OS_HANDLE
File(fd::OS_HANDLE) = new(true, fd)
end
if OS_HANDLE !== RawFD
File(fd::RawFD) = File(Libc._get_osfhandle(fd)) # TODO: calling close would now destroy the wrong handle
end
rawhandle(file::File) = file.handle
setup_stdio(file::File, ::Bool) = (file, false)
# Filesystem.open, not Base.open
function open(path::AbstractString, flags::Integer, mode::Integer=0)
req = Libc.malloc(_sizeof_uv_fs)
local handle
try
ret = ccall(:uv_fs_open, Int32,
(Ptr{Cvoid}, Ptr{Cvoid}, Cstring, Int32, Int32, Ptr{Cvoid}),
C_NULL, req, path, flags, mode, C_NULL)
handle = ccall(:uv_fs_get_result, Cssize_t, (Ptr{Cvoid},), req)
uv_fs_req_cleanup(req)
ret < 0 && uv_error("open($(repr(path)), $flags, $mode)", ret)
finally # conversion to Cstring could cause an exception
Libc.free(req)
end
return File(OS_HANDLE(@static Sys.iswindows() ? Ptr{Cvoid}(handle) : Cint(handle)))
end
isopen(f::File) = f.open
function check_open(f::File)
if !isopen(f)
throw(ArgumentError("file is closed"))
end
end
function close(f::File)
if isopen(f)
f.open = false
err = ccall(:jl_fs_close, Int32, (OS_HANDLE,), f.handle)
f.handle = INVALID_OS_HANDLE
uv_error("close", err)
end
nothing
end
closewrite(f::File) = nothing
# sendfile is the most efficient way to copy from a file descriptor
function sendfile(dst::File, src::File, src_offset::Int64, bytes::Int)
check_open(dst)
check_open(src)
while true
result = ccall(:jl_fs_sendfile, Int32, (OS_HANDLE, OS_HANDLE, Int64, Csize_t),
src.handle, dst.handle, src_offset, bytes)
uv_error("sendfile", result)
nsent = result
bytes -= nsent
src_offset += nsent
bytes <= 0 && break
end
nothing
end
function unsafe_write(f::File, buf::Ptr{UInt8}, len::UInt, offset::Int64=Int64(-1))
check_open(f)
err = ccall(:jl_fs_write, Int32, (OS_HANDLE, Ptr{UInt8}, Csize_t, Int64),
f.handle, buf, len, offset)
uv_error("write", err)
return len
end
write(f::File, c::UInt8) = write(f, Ref{UInt8}(c))
function truncate(f::File, n::Integer)
check_open(f)
req = Libc.malloc(_sizeof_uv_fs)
err = ccall(:uv_fs_ftruncate, Int32,
(Ptr{Cvoid}, Ptr{Cvoid}, OS_HANDLE, Int64, Ptr{Cvoid}),
C_NULL, req, f.handle, n, C_NULL)
Libc.free(req)
uv_error("ftruncate", err)
return f
end
function futime(f::File, atime::Float64, mtime::Float64)
check_open(f)
req = Libc.malloc(_sizeof_uv_fs)
err = ccall(:uv_fs_futime, Int32,
(Ptr{Cvoid}, Ptr{Cvoid}, OS_HANDLE, Float64, Float64, Ptr{Cvoid}),
C_NULL, req, f.handle, atime, mtime, C_NULL)
Libc.free(req)
uv_error("futime", err)
return f
end
function read(f::File, ::Type{UInt8})
check_open(f)
p = Ref{UInt8}()
ret = ccall(:jl_fs_read, Int32, (OS_HANDLE, Ptr{Cvoid}, Csize_t),
f.handle, p, 1)
uv_error("read", ret)
@assert ret <= sizeof(p) == 1
ret < 1 && throw(EOFError())
return p[] % UInt8
end
function read(f::File, ::Type{Char})
b0 = read(f, UInt8)
l = 0x08 * (0x04 - UInt8(leading_ones(b0)))
c = UInt32(b0) << 24
if l ≤ 0x10
s = 16
while s ≥ l && !eof(f)
# this works around lack of peek(::File)
p = position(f)
b = read(f, UInt8)
if b & 0xc0 != 0x80
seek(f, p)
break
end
c |= UInt32(b) << s
s -= 8
end
end
return reinterpret(Char, c)
end
read(f::File, ::Type{T}) where {T<:AbstractChar} = T(read(f, Char)) # fallback
function unsafe_read(f::File, p::Ptr{UInt8}, nel::UInt)
check_open(f)
ret = ccall(:jl_fs_read, Int32, (OS_HANDLE, Ptr{Cvoid}, Csize_t),
f.handle, p, nel)
uv_error("read", ret)
ret == nel || throw(EOFError())
nothing
end
bytesavailable(f::File) = max(0, filesize(f) - position(f)) # position can be > filesize
eof(f::File) = bytesavailable(f) == 0
function readbytes!(f::File, b::Array{UInt8}, nb=length(b))
nr = min(nb, bytesavailable(f))
if length(b) < nr
resize!(b, nr)
end
ret = ccall(:jl_fs_read, Int32, (OS_HANDLE, Ptr{Cvoid}, Csize_t),
f.handle, b, nr)
uv_error("read", ret)
return ret
end
read(io::File) = read!(io, Base.StringVector(bytesavailable(io)))
readavailable(io::File) = read(io)
read(io::File, nb::Integer) = read!(io, Base.StringVector(min(nb, bytesavailable(io))))
const SEEK_SET = Int32(0)
const SEEK_CUR = Int32(1)
const SEEK_END = Int32(2)
function seek(f::File, n::Integer)
ret = ccall(:jl_lseek, Int64, (OS_HANDLE, Int64, Int32), f.handle, n, SEEK_SET)
ret == -1 && (@static Sys.iswindows() ? windowserror : systemerror)("seek")
return f
end
function seekend(f::File)
ret = ccall(:jl_lseek, Int64, (OS_HANDLE, Int64, Int32), f.handle, 0, SEEK_END)
ret == -1 && (@static Sys.iswindows() ? windowserror : systemerror)("seekend")
return f
end
function skip(f::File, n::Integer)
ret = ccall(:jl_lseek, Int64, (OS_HANDLE, Int64, Int32), f.handle, n, SEEK_CUR)
ret == -1 && (@static Sys.iswindows() ? windowserror : systemerror)("skip")
return f
end
function position(f::File)
check_open(f)
ret = ccall(:jl_lseek, Int64, (OS_HANDLE, Int64, Int32), f.handle, 0, SEEK_CUR)
ret == -1 && (@static Sys.iswindows() ? windowserror : systemerror)("lseek")
return ret
end
fd(f::File) = f.handle
stat(f::File) = stat(f.handle)
function touch(f::File)
@static if Sys.isunix()
ret = ccall(:futimes, Cint, (Cint, Ptr{Cvoid}), fd(f), C_NULL)
systemerror(:futimes, ret != 0)
else
t = time()
futime(f, t, t)
end
f
end
"""
isexecutable(path::String)
Return `true` if the given `path` has executable permissions.
!!! note
This permission may change before the user executes `path`,
so it is recommended to execute the file and handle the error if that fails,
rather than calling `isexecutable` first.
!!! note
Prior to Julia 1.6, this did not correctly interrogate filesystem
ACLs on Windows, therefore it would return `true` for any
file. From Julia 1.6 on, it correctly determines whether the
file is marked as executable or not.
See also [`ispath`](@ref), [`isreadable`](@ref), [`iswritable`](@ref).
"""
function isexecutable(path::String)
# We use `access()` and `X_OK` to determine if a given path is
# executable by the current user. `X_OK` comes from `unistd.h`.
X_OK = 0x01
return ccall(:jl_fs_access, Cint, (Cstring, Cint), path, X_OK) == 0
end
isexecutable(path::AbstractString) = isexecutable(String(path))
"""
isreadable(path::String)
Return `true` if the access permissions for the given `path` permitted reading by the current user.
!!! note
This permission may change before the user calls `open`,
so it is recommended to just call `open` alone and handle the error if that fails,
rather than calling `isreadable` first.
!!! note
Currently this function does not correctly interrogate filesystem
ACLs on Windows, therefore it can return wrong results.
!!! compat "Julia 1.11"
This function requires at least Julia 1.11.
See also [`ispath`](@ref), [`isexecutable`](@ref), [`iswritable`](@ref).
"""
function isreadable(path::String)
# We use `access()` and `R_OK` to determine if a given path is
# readable by the current user. `R_OK` comes from `unistd.h`.
R_OK = 0x04
return ccall(:jl_fs_access, Cint, (Cstring, Cint), path, R_OK) == 0
end
isreadable(path::AbstractString) = isreadable(String(path))
"""
iswritable(path::String)
Return `true` if the access permissions for the given `path` permitted writing by the current user.
!!! note
This permission may change before the user calls `open`,
so it is recommended to just call `open` alone and handle the error if that fails,
rather than calling `iswritable` first.
!!! note
Currently this function does not correctly interrogate filesystem
ACLs on Windows, therefore it can return wrong results.
!!! compat "Julia 1.11"
This function requires at least Julia 1.11.
See also [`ispath`](@ref), [`isexecutable`](@ref), [`isreadable`](@ref).
"""
function iswritable(path::String)
# We use `access()` and `W_OK` to determine if a given path is
# writeable by the current user. `W_OK` comes from `unistd.h`.
W_OK = 0x02
return ccall(:jl_fs_access, Cint, (Cstring, Cint), path, W_OK) == 0
end
iswritable(path::AbstractString) = iswritable(String(path))
end
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