diff options
Diffstat (limited to 'lib/std/private/osfiles.nim')
| -rw-r--r-- | lib/std/private/osfiles.nim | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/lib/std/private/osfiles.nim b/lib/std/private/osfiles.nim new file mode 100644 index 000000000..37d8eabca --- /dev/null +++ b/lib/std/private/osfiles.nim @@ -0,0 +1,416 @@ +include system/inclrtl +import std/private/since +import std/oserrors + +import oscommon +export fileExists + +import ospaths2, ossymlinks + +## .. importdoc:: osdirs.nim, os.nim + +when defined(nimPreviewSlimSystem): + import std/[syncio, assertions, widestrs] + +when weirdTarget: + discard +elif defined(windows): + import std/winlean +elif defined(posix): + import std/[posix, times] + + proc toTime(ts: Timespec): times.Time {.inline.} = + result = initTime(ts.tv_sec.int64, ts.tv_nsec.int) +else: + {.error: "OS module not ported to your operating system!".} + + +when weirdTarget: + {.pragma: noWeirdTarget, error: "this proc is not available on the NimScript/js target".} +else: + {.pragma: noWeirdTarget.} + + +when defined(nimscript): + # for procs already defined in scriptconfig.nim + template noNimJs(body): untyped = discard +elif defined(js): + {.pragma: noNimJs, error: "this proc is not available on the js target".} +else: + {.pragma: noNimJs.} + + +type + FilePermission* = enum ## File access permission, modelled after UNIX. + ## + ## See also: + ## * `getFilePermissions`_ + ## * `setFilePermissions`_ + ## * `FileInfo object`_ + fpUserExec, ## execute access for the file owner + fpUserWrite, ## write access for the file owner + fpUserRead, ## read access for the file owner + fpGroupExec, ## execute access for the group + fpGroupWrite, ## write access for the group + fpGroupRead, ## read access for the group + fpOthersExec, ## execute access for others + fpOthersWrite, ## write access for others + fpOthersRead ## read access for others + +proc getFilePermissions*(filename: string): set[FilePermission] {. + rtl, extern: "nos$1", tags: [ReadDirEffect], noWeirdTarget.} = + ## Retrieves file permissions for `filename`. + ## + ## `OSError` is raised in case of an error. + ## On Windows, only the ``readonly`` flag is checked, every other + ## permission is available in any case. + ## + ## See also: + ## * `setFilePermissions proc`_ + ## * `FilePermission enum`_ + when defined(posix): + var a: Stat + if stat(filename, a) < 0'i32: raiseOSError(osLastError(), filename) + result = {} + if (a.st_mode and S_IRUSR.Mode) != 0.Mode: result.incl(fpUserRead) + if (a.st_mode and S_IWUSR.Mode) != 0.Mode: result.incl(fpUserWrite) + if (a.st_mode and S_IXUSR.Mode) != 0.Mode: result.incl(fpUserExec) + + if (a.st_mode and S_IRGRP.Mode) != 0.Mode: result.incl(fpGroupRead) + if (a.st_mode and S_IWGRP.Mode) != 0.Mode: result.incl(fpGroupWrite) + if (a.st_mode and S_IXGRP.Mode) != 0.Mode: result.incl(fpGroupExec) + + if (a.st_mode and S_IROTH.Mode) != 0.Mode: result.incl(fpOthersRead) + if (a.st_mode and S_IWOTH.Mode) != 0.Mode: result.incl(fpOthersWrite) + if (a.st_mode and S_IXOTH.Mode) != 0.Mode: result.incl(fpOthersExec) + else: + wrapUnary(res, getFileAttributesW, filename) + if res == -1'i32: raiseOSError(osLastError(), filename) + if (res and FILE_ATTRIBUTE_READONLY) != 0'i32: + result = {fpUserExec, fpUserRead, fpGroupExec, fpGroupRead, + fpOthersExec, fpOthersRead} + else: + result = {fpUserExec..fpOthersRead} + +proc setFilePermissions*(filename: string, permissions: set[FilePermission], + followSymlinks = true) + {.rtl, extern: "nos$1", tags: [ReadDirEffect, WriteDirEffect], + noWeirdTarget.} = + ## Sets the file permissions for `filename`. + ## + ## If `followSymlinks` set to true (default) and ``filename`` points to a + ## symlink, permissions are set to the file symlink points to. + ## `followSymlinks` set to false is a noop on Windows and some POSIX + ## systems (including Linux) on which `lchmod` is either unavailable or always + ## fails, given that symlinks permissions there are not observed. + ## + ## `OSError` is raised in case of an error. + ## On Windows, only the ``readonly`` flag is changed, depending on + ## ``fpUserWrite`` permission. + ## + ## See also: + ## * `getFilePermissions proc`_ + ## * `FilePermission enum`_ + when defined(posix): + var p = 0.Mode + if fpUserRead in permissions: p = p or S_IRUSR.Mode + if fpUserWrite in permissions: p = p or S_IWUSR.Mode + if fpUserExec in permissions: p = p or S_IXUSR.Mode + + if fpGroupRead in permissions: p = p or S_IRGRP.Mode + if fpGroupWrite in permissions: p = p or S_IWGRP.Mode + if fpGroupExec in permissions: p = p or S_IXGRP.Mode + + if fpOthersRead in permissions: p = p or S_IROTH.Mode + if fpOthersWrite in permissions: p = p or S_IWOTH.Mode + if fpOthersExec in permissions: p = p or S_IXOTH.Mode + + if not followSymlinks and filename.symlinkExists: + when declared(lchmod): + if lchmod(filename, cast[Mode](p)) != 0: + raiseOSError(osLastError(), $(filename, permissions)) + else: + if chmod(filename, cast[Mode](p)) != 0: + raiseOSError(osLastError(), $(filename, permissions)) + else: + wrapUnary(res, getFileAttributesW, filename) + if res == -1'i32: raiseOSError(osLastError(), filename) + if fpUserWrite in permissions: + res = res and not FILE_ATTRIBUTE_READONLY + else: + res = res or FILE_ATTRIBUTE_READONLY + wrapBinary(res2, setFileAttributesW, filename, res) + if res2 == - 1'i32: raiseOSError(osLastError(), $(filename, permissions)) + + +const hasCCopyfile = defined(osx) and not defined(nimLegacyCopyFile) + # xxx instead of `nimLegacyCopyFile`, support something like: `when osxVersion >= (10, 5)` + +when hasCCopyfile: + # `copyfile` API available since osx 10.5. + {.push nodecl, header: "<copyfile.h>".} + type + copyfile_state_t {.nodecl.} = pointer + copyfile_flags_t = cint + proc copyfile_state_alloc(): copyfile_state_t + proc copyfile_state_free(state: copyfile_state_t): cint + proc c_copyfile(src, dst: cstring, state: copyfile_state_t, flags: copyfile_flags_t): cint {.importc: "copyfile".} + when (NimMajor, NimMinor) >= (1, 4): + let + COPYFILE_DATA {.nodecl.}: copyfile_flags_t + COPYFILE_XATTR {.nodecl.}: copyfile_flags_t + else: + var + COPYFILE_DATA {.nodecl.}: copyfile_flags_t + COPYFILE_XATTR {.nodecl.}: copyfile_flags_t + {.pop.} + +type + CopyFlag* = enum ## Copy options. + cfSymlinkAsIs, ## Copy symlinks as symlinks + cfSymlinkFollow, ## Copy the files symlinks point to + cfSymlinkIgnore ## Ignore symlinks + +const copyFlagSymlink = {cfSymlinkAsIs, cfSymlinkFollow, cfSymlinkIgnore} + +proc copyFile*(source, dest: string, options = {cfSymlinkFollow}; bufferSize = 16_384) {.rtl, + extern: "nos$1", tags: [ReadDirEffect, ReadIOEffect, WriteIOEffect], + noWeirdTarget.} = + ## Copies a file from `source` to `dest`, where `dest.parentDir` must exist. + ## + ## On non-Windows OSes, `options` specify the way file is copied; by default, + ## if `source` is a symlink, copies the file symlink points to. `options` is + ## ignored on Windows: symlinks are skipped. + ## + ## If this fails, `OSError` is raised. + ## + ## On the Windows platform this proc will + ## copy the source file's attributes into dest. + ## + ## On other platforms you need + ## to use `getFilePermissions`_ and + ## `setFilePermissions`_ + ## procs + ## to copy them by hand (or use the convenience `copyFileWithPermissions + ## proc`_), + ## otherwise `dest` will inherit the default permissions of a newly + ## created file for the user. + ## + ## If `dest` already exists, the file attributes + ## will be preserved and the content overwritten. + ## + ## On OSX, `copyfile` C api will be used (available since OSX 10.5) unless + ## `-d:nimLegacyCopyFile` is used. + ## + ## `copyFile` allows to specify `bufferSize` to improve I/O performance. + ## + ## See also: + ## * `CopyFlag enum`_ + ## * `copyDir proc`_ + ## * `copyFileWithPermissions proc`_ + ## * `tryRemoveFile proc`_ + ## * `removeFile proc`_ + ## * `moveFile proc`_ + + doAssert card(copyFlagSymlink * options) == 1, "There should be exactly one cfSymlink* in options" + let isSymlink = source.symlinkExists + if isSymlink and (cfSymlinkIgnore in options or defined(windows)): + return + when defined(windows): + let s = newWideCString(source) + let d = newWideCString(dest) + if copyFileW(s, d, 0'i32) == 0'i32: + raiseOSError(osLastError(), $(source, dest)) + else: + if isSymlink and cfSymlinkAsIs in options: + createSymlink(expandSymlink(source), dest) + else: + when hasCCopyfile: + let state = copyfile_state_alloc() + # xxx `COPYFILE_STAT` could be used for one-shot + # `copyFileWithPermissions`. + let status = c_copyfile(source.cstring, dest.cstring, state, + COPYFILE_DATA) + if status != 0: + let err = osLastError() + discard copyfile_state_free(state) + raiseOSError(err, $(source, dest)) + let status2 = copyfile_state_free(state) + if status2 != 0: raiseOSError(osLastError(), $(source, dest)) + else: + # generic version of copyFile which works for any platform: + var d, s: File + if not open(s, source): raiseOSError(osLastError(), source) + if not open(d, dest, fmWrite): + close(s) + raiseOSError(osLastError(), dest) + + # Hints for kernel-level aggressive sequential low-fragmentation read-aheads: + # https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fadvise.html + when defined(linux) or defined(osx): + discard posix_fadvise(getFileHandle(d), 0.cint, 0.cint, POSIX_FADV_SEQUENTIAL) + discard posix_fadvise(getFileHandle(s), 0.cint, 0.cint, POSIX_FADV_SEQUENTIAL) + + var buf = alloc(bufferSize) + while true: + var bytesread = readBuffer(s, buf, bufferSize) + if bytesread > 0: + var byteswritten = writeBuffer(d, buf, bytesread) + if bytesread != byteswritten: + dealloc(buf) + close(s) + close(d) + raiseOSError(osLastError(), dest) + if bytesread != bufferSize: break + dealloc(buf) + close(s) + flushFile(d) + close(d) + +proc copyFileToDir*(source, dir: string, options = {cfSymlinkFollow}; bufferSize = 16_384) + {.noWeirdTarget, since: (1,3,7).} = + ## Copies a file `source` into directory `dir`, which must exist. + ## + ## On non-Windows OSes, `options` specify the way file is copied; by default, + ## if `source` is a symlink, copies the file symlink points to. `options` is + ## ignored on Windows: symlinks are skipped. + ## + ## `copyFileToDir` allows to specify `bufferSize` to improve I/O performance. + ## + ## See also: + ## * `CopyFlag enum`_ + ## * `copyFile proc`_ + if dir.len == 0: # treating "" as "." is error prone + raise newException(ValueError, "dest is empty") + copyFile(source, dir / source.lastPathPart, options, bufferSize) + + +proc copyFileWithPermissions*(source, dest: string, + ignorePermissionErrors = true, + options = {cfSymlinkFollow}) {.noWeirdTarget.} = + ## Copies a file from `source` to `dest` preserving file permissions. + ## + ## On non-Windows OSes, `options` specify the way file is copied; by default, + ## if `source` is a symlink, copies the file symlink points to. `options` is + ## ignored on Windows: symlinks are skipped. + ## + ## This is a wrapper proc around `copyFile`_, + ## `getFilePermissions`_ and `setFilePermissions`_ + ## procs on non-Windows platforms. + ## + ## On Windows this proc is just a wrapper for `copyFile proc`_ since + ## that proc already copies attributes. + ## + ## On non-Windows systems permissions are copied after the file itself has + ## been copied, which won't happen atomically and could lead to a race + ## condition. If `ignorePermissionErrors` is true (default), errors while + ## reading/setting file attributes will be ignored, otherwise will raise + ## `OSError`. + ## + ## See also: + ## * `CopyFlag enum`_ + ## * `copyFile proc`_ + ## * `copyDir proc`_ + ## * `tryRemoveFile proc`_ + ## * `removeFile proc`_ + ## * `moveFile proc`_ + ## * `copyDirWithPermissions proc`_ + copyFile(source, dest, options) + when not defined(windows): + try: + setFilePermissions(dest, getFilePermissions(source), followSymlinks = + (cfSymlinkFollow in options)) + except: + if not ignorePermissionErrors: + raise + +when not declared(ENOENT) and not defined(windows): + when defined(nimscript): + when not defined(haiku): + const ENOENT = cint(2) # 2 on most systems including Solaris + else: + const ENOENT = cint(-2147459069) + else: + var ENOENT {.importc, header: "<errno.h>".}: cint + +when defined(windows) and not weirdTarget: + template deleteFile(file: untyped): untyped = deleteFileW(file) + template setFileAttributes(file, attrs: untyped): untyped = + setFileAttributesW(file, attrs) + +proc tryRemoveFile*(file: string): bool {.rtl, extern: "nos$1", tags: [WriteDirEffect], noWeirdTarget.} = + ## Removes the `file`. + ## + ## If this fails, returns `false`. This does not fail + ## if the file never existed in the first place. + ## + ## On Windows, ignores the read-only attribute. + ## + ## See also: + ## * `copyFile proc`_ + ## * `copyFileWithPermissions proc`_ + ## * `removeFile proc`_ + ## * `moveFile proc`_ + result = true + when defined(windows): + let f = newWideCString(file) + if deleteFile(f) == 0: + result = false + let err = getLastError() + if err == ERROR_FILE_NOT_FOUND or err == ERROR_PATH_NOT_FOUND: + result = true + elif err == ERROR_ACCESS_DENIED and + setFileAttributes(f, FILE_ATTRIBUTE_NORMAL) != 0 and + deleteFile(f) != 0: + result = true + else: + if unlink(file) != 0'i32 and errno != ENOENT: + result = false + +proc removeFile*(file: string) {.rtl, extern: "nos$1", tags: [WriteDirEffect], noWeirdTarget.} = + ## Removes the `file`. + ## + ## If this fails, `OSError` is raised. This does not fail + ## if the file never existed in the first place. + ## + ## On Windows, ignores the read-only attribute. + ## + ## See also: + ## * `removeDir proc`_ + ## * `copyFile proc`_ + ## * `copyFileWithPermissions proc`_ + ## * `tryRemoveFile proc`_ + ## * `moveFile proc`_ + if not tryRemoveFile(file): + raiseOSError(osLastError(), file) + +proc moveFile*(source, dest: string) {.rtl, extern: "nos$1", + tags: [ReadDirEffect, ReadIOEffect, WriteIOEffect], noWeirdTarget.} = + ## Moves a file from `source` to `dest`. + ## + ## Symlinks are not followed: if `source` is a symlink, it is itself moved, + ## not its target. + ## + ## If this fails, `OSError` is raised. + ## If `dest` already exists, it will be overwritten. + ## + ## Can be used to `rename files`:idx:. + ## + ## See also: + ## * `moveDir proc`_ + ## * `copyFile proc`_ + ## * `copyFileWithPermissions proc`_ + ## * `removeFile proc`_ + ## * `tryRemoveFile proc`_ + + if not tryMoveFSObject(source, dest, isDir = false): + when defined(windows): + raiseAssert "unreachable" + else: + # Fallback to copy & del + copyFileWithPermissions(source, dest, options={cfSymlinkAsIs}) + try: + removeFile(source) + except: + discard tryRemoveFile(dest) + raise |