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address review comments
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@a-mr
a-mr committed Feb 8, 2020
1 parent 5b554d8 commit 5838315
Showing 1 changed file with 80 additions and 90 deletions.
170 changes: 80 additions & 90 deletions lib/pure/os.nim
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Original file line number Diff line number Diff line change
Expand Up @@ -2096,38 +2096,32 @@ iterator walkDir*(dir: string; relative=false): tuple[kind: PathComponent, path:
yield (k, y)

type
OpenDirStatus* = enum ## enumeration specifying status of opening a directory
odUnknownError, ## unrecognized error
odOpenOk, ## the directory was opened OK
odNotDir, ## error, not a directory: a file with the same path exists
odAccessDenied, ## permission denied / access denied error
odNotFound ## no such path
WalkStepKind* = enum ## status of the step of walking through directory
wsOpenDir, ## step for attempt to open directory
wsEntryOk, ## step when entry is OK
wsEntryBad ## a broken symlink on posix, where it's unclear if it
## points to a file or directory
wsInterrupted ## the directory handle got invalidated during reading
WalkStepKind* = enum ## status of the step of walking through directory.
## Due to differences between operating systems,
## opening directory status may not have exactly
## the same meaning.
wsDirFailure, ## opening directory error: unrecognized OS-specific
wsDirNotFound, ## opening directory error: no such path
wsDirNoAccess, ## opening directory error: access denied a.k.a.
## permission denied error for the specified path
## (may have happened at its parent directory on posix)
wsNotDir, ## opening directory error: not a directory
## (a normal file with the same path exists)
wsDirOpened, ## opening directory OK, the directory can be read
wsEntryOk, ## entry OK: path component is right
wsEntryBad ## entry error: a broken symlink (on posix), where it's
## unclear if it points to a file or directory
wsInterrupted ## reading directory entries was interrupted
WalkStep* = object ## step of walking through directory
path*: string ## the path that this step applies to
code*: OSErrorCode ## OS error code for the step
case kind*: WalkStepKind ## discriminator
of wsOpenDir:
openStatus*: OpenDirStatus ## status of opening the directory
of wsEntryOk:
entryType*: PathComponent ## path component
of wsEntryBad, wsInterrupted:
of wsDirFailure, wsDirNoAccess, wsDirNotFound, wsNotDir,
wsDirOpened, wsEntryBad, wsInterrupted:
discard

proc `$`*(s: WalkStep): string =
let err = if s.code == OSErrorCode(0): ""
else: " ($1 - $2)" % [$s.code, osErrorMsg(s.code)]
case s.kind
of wsOpenDir: "(wsOpenDir | $1 '$2'$3)" % [$s.openStatus, s.path, err]
of wsEntryOk: "(wsEntryOk | $1 '$2')" % [$s.entryType, s.path]
of wsEntryBad: "(wsEntryBad | '$1'$2)" % [s.path, err]
of wsInterrupted: "(wsInterrupted | '$1'$2)" % [s.path, err]

iterator tryWalkDir*(dir: string, relative=false): WalkStep {.
tags: [ReadDirEffect], raises: [], noNimScript, since: (1, 1).} =
## Walks over the directory `dir` and yields *steps* for each
Expand All @@ -2138,52 +2132,46 @@ iterator tryWalkDir*(dir: string, relative=false): WalkStep {.
## Each step is object variant ``WalkStep``, which contains corresponding
## path ``path``, OS error code ``code`` and discriminator ``kind``:
##
## - ``kind=wsOpenDir`` is yielded once after opening, contains ``openStatus``
## of type ``OpenDirStatus``
## (when `relative=true` the path is '.')
## - it yields open directory status once after opening
## (when `relative=true` the path is '.'),
## ``kind`` is one of ``wsDirOpened``, ``wsDirNoAccess``,
## ``wsDirNotFound``, ``wsNotDir``, ``wsDirFailure``
## - then it yields zero or more entries, each can be of the following kind:
## - ``kind=wsEntryOk``: signifies normal entries with
## path component ``entryType``
## path component ``entryType``
## - ``kind=wsEntryBad``: broken symlink (without path component)
## - ``kind=wsInterrupted``: signifies that a rare OS error happenned and
## the walking was terminated
## - ``kind=wsInterrupted``: signifies that a rare OS-specific I/O error
## happenned and the walking was terminated.
##
## An example of usage with full error logging:
## An example of usage with just minimal error logging:
## .. code-block:: Nim
## for step in tryWalkDir("dirA"):
## let err = " (" & $step.code & " - " & osErrorMsg(step.code) & ")"
## case step.kind
## of wsOpenDir:
## case step.openStatus:
## of odOpenOk: echo "directory is opened OK"
## of odNotDir: echo "is not a directory" & err
## of odAccessDenied: echo "Access Denied" & err
## of odNotFound: echo "no such path" & err
## of odUnknownError: echo "unknown error - that's bad." & err
## of wsDirOpened: discard
## of wsEntryOk: echo step.path & " is entry of kind " & $step.entryType
## of wsEntryBad: echo step.path & " is broken symlink " & err
## of wsInterrupted: echo " traversal interrupted, really bad. " & err
## else: echo "got error " & osErrorMsg(step.code) & " on " & step.path
##
## For comparison, walkDir iterator may be implemented with tryWalkDir:
## Iterator ``walkDir`` itself may be implemented using tryWalkDir:
## .. code-block:: Nim
## iterator myWalkDir(path: string, relative: bool):
## tuple[kind: PathComponent, path: string] =
## tuple[kind: PathComponent, path: string] =
## for step in tryWalkDir(path, relative):
## case step.kind
## of wsOpenDir: discard
## of wsDirOpened, wsDirNotFound,
## wsDirNoAccess, wsDirNoAccess, wsNotDir: discard
## of wsEntryOk: yield (step.entryType, step.path)
## of wsEntryBad: yield (pcLinkToFile, step.path)
## of wsInterrupted: raiseOSError(step.code)

var step: WalkStep
var skip = false
let outDir = if relative: "." else: dir
proc sOpenDir(s: OpenDirStatus, path: string): WalkStep =
let code = if s == odOpenOk: OSErrorCode(0) else: osLastError()
result = WalkStep(kind: wsOpenDir, openStatus: s, code: code, path: path)
proc sNoErrors(pc: PathComponent, path: string): WalkStep =
proc openStatus(s: WalkStepKind, path: string): WalkStep =
let code = if s == wsDirOpened: OSErrorCode(0) else: osLastError()
result = WalkStep(kind: s, code: code, path: path)
proc entryOk(pc: PathComponent, path: string): WalkStep =
WalkStep(kind: wsEntryOk, entryType: pc, code: OSErrorCode(0), path: path)
proc sGetError(k: WalkStepKind, path: string): WalkStep =
proc entryError(k: WalkStepKind, path: string): WalkStep =
WalkStep(kind: k, code: osLastError(), path: path)

when defined(windows):
Expand All @@ -2195,22 +2183,23 @@ iterator tryWalkDir*(dir: string, relative=false): WalkStep {.
k = succ(k)
let xx = if relative: extractFilename(getFilename(fdat))
else: dir / extractFilename(getFilename(fdat))
sNoErrors(k, xx)
entryOk(k, xx)

var f: WIN32_FIND_DATA
var h: Handle = findFirstFile(dir / "*", f)
defer:
if h != -1:
findClose(h)
let status =
if h == -1:
if h != -1:
wsDirOpened
else:
case getLastError()
of ERROR_PATH_NOT_FOUND: odNotFound
of ERROR_DIRECTORY: odNotDir
of ERROR_ACCESS_DENIED: odAccessDenied
else: odUnknownError
else: odOpenOk
step = sOpenDir(status, outDir)
of ERROR_PATH_NOT_FOUND: wsDirNotFound
of ERROR_DIRECTORY: wsNotDir
of ERROR_ACCESS_DENIED: wsDirNoAccess
else: wsDirFailure
step = openStatus(status, outDir)

var firstStep = true
while true:
Expand All @@ -2220,19 +2209,21 @@ iterator tryWalkDir*(dir: string, relative=false): WalkStep {.
break
if firstStep: # use file obtained by findFirstFile
firstStep = false
skip = skipFindData(f)
if not skip:
step = resolveFile(f, relative)
else: # get next file
if findNextFile(h, f) == 0'i32:
if findNextFile(h, f) != 0'i32:
skip = skipFindData(f)
if not skip:
step = resolveFile(f, relative)
else:
let errCode = getLastError()
if errCode == ERROR_NO_MORE_FILES:
break # normal end, yielding nothing
else:
skip = false
step = sGetError(wsInterrupted, outDir)
continue
skip = skipFindData(f)
if not skip:
step = resolveFile(f, relative)

step = entryError(wsInterrupted, outDir)
else:
proc resolveFile(x: ptr Dirent, path: string, y: string): WalkStep =
var k = pcFile
Expand All @@ -2241,23 +2232,23 @@ iterator tryWalkDir*(dir: string, relative=false): WalkStep {.
if x.d_type != DT_UNKNOWN:
if x.d_type == DT_DIR:
k = pcDir
return sNoErrors(k, y)
return entryOk(k, y)
elif x.d_type == DT_LNK:
errno = 0
if dirExists(path): k = pcLinkToDir
else: k = pcLinkToFile
# check error in dirExists
if errno == 0:
return sNoErrors(k, y)
return entryOk(k, y)
else:
return sGetError(wsEntryBad, y)
return entryError(wsEntryBad, y)
else:
return sNoErrors(k, y)
return entryOk(k, y)
# case of d_type==DT_UNKNOWN: some filesystems don't report
# the entry type; one should fallback to lstat
var s: Stat
if lstat(path, s) < 0'i32:
return sGetError(wsEntryBad, y)
return entryError(wsEntryBad, y)
else:
errno = 0
if S_ISDIR(s.st_mode):
Expand All @@ -2266,49 +2257,48 @@ iterator tryWalkDir*(dir: string, relative=false): WalkStep {.
k = getSymlinkFileKind(path)
# check error in getSymlinkFileKind
if errno == 0:
return sNoErrors(k, y)
return entryOk(k, y)
else:
return sGetError(wsEntryBad, y)
return entryError(wsEntryBad, y)

var d: ptr DIR = opendir(dir)
defer:
if d != nil:
discard closedir(d)
let status =
if d == nil:
if errno == ENOENT: odNotFound
elif errno == ENOTDIR: odNotDir
elif errno == EACCES: odAccessDenied
else: odUnknownError
else: odOpenOk
step = sOpenDir(status, outDir)
if d != nil:
wsDirOpened
else:
if errno == ENOENT: wsDirNotFound
elif errno == ENOTDIR: wsNotDir
elif errno == EACCES: wsDirNoAccess
else: wsDirFailure
step = openStatus(status, outDir)

while true:
if not skip:
yield step
if d == nil or step.kind == wsInterrupted:
break
let errnoSave = errno
defer: errno = errnoSave
errno = 0
var x = readdir(d)
if x == nil:
if errno == 0:
errno = errnoSave
break # normal end, yielding nothing
else:
skip = false
step = sGetError(wsInterrupted, outDir)
continue
when defined(nimNoArrayToCstringConversion):
var y = $cstring(addr x.d_name)
step = entryError(wsInterrupted, outDir)
else:
var y = $x.d_name.cstring
skip = (y == "." or y == "..")
if not skip:
let path = dir / y
if not relative:
y = path
step = resolveFile(x, path, y)
var y = $cstring(addr x.d_name)
skip = (y == "." or y == "..")
if not skip:
let path = dir / y
if not relative:
y = path
step = resolveFile(x, path, y)
errno = errnoSave

iterator walkDirRec*(dir: string,
yieldFilter = {pcFile}, followFilter = {pcDir},
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