ref: 943c865bcfacb00af4c681fc36fbcab2b7f9a55f
parent: 1f4389df622ed274371d0c134ffd3b1c5a94bd48
author: Ori Bernstein <ori@eigenstate.org>
date: Wed Sep 13 11:04:40 EDT 2017
Add loop checking to libfileutil.
--- a/lib/fileutil/bld.sub
+++ b/lib/fileutil/bld.sub
@@ -3,6 +3,9 @@
homedir.myr
tmpdir.myr
+ loopcheck+posixy.myr
+ loopcheck+plan9.myr
+
lib ../sys:sys
lib ../std:std
;;
--- /dev/null
+++ b/lib/fileutil/loopcheck+plan9.myr
@@ -1,0 +1,21 @@
+use std
+
+/* plan 9 can't have directory loops, by construction, so this is nops */
+pkg fileutil =
+ type loopcheck = void
+
+ const mkloopcheck : (cwd : byte[:] -> loopcheck)
+ const freeloopcheck : (l : loopcheck -> void)
+ const looped : (l : loopcheck, p : byte[:] -> bool)
+;;
+
+const mkloopcheck = {cwd+ -> (void : loopcheck)
+}
+
+const freeloopcheck = {l, l+}
+
+const looped = {p+ -> false
+}
--- /dev/null
+++ b/lib/fileutil/loopcheck+posixy.myr
@@ -1,0 +1,65 @@
+use std
+use sys
+
+/* plan 9 can't have directory loops, by construction, so this is nops */
+pkg fileutil =
+ type loopcheck = std.htab((int64, int64), void)#
+
+ const mkloopcheck : (cwd : byte[:] -> loopcheck)
+ const freeloopcheck : (l : loopcheck -> void)
+ const looped : (l : loopcheck, p : byte[:] -> bool)
+;;
+
+const mkloopcheck = {cwd+ var ht : std.htab((int64, int64), void)#
+ var l
+
+ ht = std.mkht(fidhash, fideq)
+ l = (ht : loopcheck)
+ looped(l, cwd)
+ -> l
+}
+
+const freeloopcheck = {l+ std.htfree((l : std.htab((int64, int64), void)#))
+}
+
+const looped = {l, p+ var ht, has
+
+ ht = (l : std.htab((int64, int64), void)#)
+ match fid(p)
+ | `std.Err e:
+ -> false
+ | `std.Ok id:
+ has = std.hthas(ht, id)
+ std.htput(ht, id, void)
+ -> has
+ ;;
+}
+
+const fid = {p+ var sb
+
+ if sys.stat(p, &sb) != 0
+ -> `std.Err void
+ else
+ -> `std.Ok ((sb.dev : int64), (sb.ino : int64))
+ ;;
+}
+
+const fidhash = {fid+ var dev, ino
+
+ (dev, ino) = fid
+ -> std.inthash(dev) ^ std.inthash(ino)
+}
+
+const fideq = {a, b+ var adev, aino
+ var bdev, bino
+
+ (adev, aino) = a
+ (bdev, bino) = b
+ -> adev == bdev && aino == bino
+}
--- a/lib/fileutil/walk.myr
+++ b/lib/fileutil/walk.myr
@@ -1,9 +1,12 @@
use std
+use "loopcheck"
+
pkg fileutil =
type walkiter = struct
dirstk : std.dir#[:]
curdir : byte[:][:]
+ loopck : loopcheck
;;
impl iterable walkiter -> byte[:]
@@ -13,9 +16,16 @@
const bywalk = {pmatch std.diropen(p)
| `std.Ok d:
- -> [.dirstk = std.sldup([d][:]), .curdir = std.sldup([std.sldup(p)][:])]
+ -> [
+ .dirstk = std.sldup([d][:]),
+ .curdir = std.sldup([std.sldup(p)][:]),
+ .loopck = mkloopcheck(p),
+ ]
| `std.Err e:
- -> [.dirstk = [][:], .curdir = [][:]]
+ -> [
+ .dirstk = [][:],
+ .curdir = [][:]
+ ]
;;
}
@@ -25,6 +35,7 @@
:nextfile
if itp.dirstk.len < 1
+ freeloopcheck(itp.loopck)
-> false
;;
cur = itp.dirstk[itp.dirstk.len - 1]
@@ -33,6 +44,10 @@
| `std.Some "..": goto nextfile
| `std.Some ent:
p = std.pathcat(itp.curdir[itp.curdir.len - 1], ent)
+ if looped(itp.loopck, p)
+ std.slfree(p)
+ goto nextfile
+ ;;
if std.fisdir(p)
match std.diropen(p)
| `std.Ok d: