Add prefix argument to mktempdir()

base/file.jl

@@ -254,6 +254,8 @@ function touch(path::AbstractString)
     end
 end
 
+const temp_prefix = "jl_"
+
 if Sys.iswindows()
 
 function tempdir()
@@ -265,13 +267,17 @@ function tempdir()
     resize!(temppath,lentemppath)
     return transcode(String, temppath)
 end
+
 tempname(uunique::UInt32=UInt32(0)) = tempname(tempdir(), uunique)
-const temp_prefix = cwstring("jl_")
+
 function tempname(temppath::AbstractString,uunique::UInt32)
     tempp = cwstring(temppath)
+    temppfx = cwstring(temp_prefix)
     tname = Vector{UInt16}(32767)
-    uunique = ccall(:GetTempFileNameW,stdcall,UInt32,(Ptr{UInt16},Ptr{UInt16},UInt32,Ptr{UInt16}), tempp,temp_prefix,uunique,tname)
-    lentname = findfirst(iszero,tname)-1
+    uunique = ccall(:GetTempFileNameW,stdcall,UInt32,
+                    (Ptr{UInt16}, Ptr{UInt16}, UInt32, Ptr{UInt16}),
+                    tempp, temppfx, uunique, tname)
+    lentname = findfirst(iszero, tname)-1
     if uunique == 0 || lentname <= 0
         error("GetTempFileName failed: $(Libc.FormatMessage())")
     end
@@ -284,22 +290,6 @@ function mktemp(parent=tempdir())
     return (filename, Base.open(filename, "r+"))
 end
 
-function mktempdir(parent=tempdir())
-    seed::UInt32 = rand(UInt32)
-    while true
-        if (seed & typemax(UInt16)) == 0
-            seed += 1
-        end
-        filename = tempname(parent, seed)
-        ret = ccall(:_wmkdir, Int32, (Ptr{UInt16},), cwstring(filename))
-        if ret == 0
-            return filename
-        end
-        systemerror(:mktempdir, Libc.errno()!=Libc.EEXIST)
-        seed += 1
-    end
-end
-
 else # !windows
 # Obtain a temporary filename.
 function tempname()
@@ -322,13 +312,6 @@ function mktemp(parent=tempdir())
     return (b, fdio(p, true))
 end
 
-# Create and return the name of a temporary directory
-function mktempdir(parent=tempdir())
-    b = joinpath(parent, "tmpXXXXXX")
-    p = ccall(:mkdtemp, Cstring, (Cstring,), b)
-    systemerror(:mktempdir, p == C_NULL)
-    return unsafe_string(p)
-end
 
 end # os-test
 
@@ -356,13 +339,42 @@ is an open file object for this path.
 mktemp(parent)
 
 """
-    mktempdir(parent=tempdir())
+    mktempdir(parent=tempdir(); prefix="$(repr(temp_prefix))")
 
 Create a temporary directory in the `parent` directory and return its path.
 If `parent` does not exist, throw an error.
+An optional `prefix` to the directory name can be provided.
 """
-mktempdir(parent)
+function mktempdir(parent=tempdir(); prefix=temp_prefix)
+    i = endof(parent)
+    while i >= 1 && parent[i:i] == path_separator
+        i -= 1
+    end
+    parent = parent[1:i]
+    i = 1
+    while i <= endof(prefix) && prefix[i:i] == path_separator
+        i += 1
+    end
+    prefix = prefix[i:end]
 
+    tpath = "$(parent)$(path_separator)$(prefix)XXXXXX"
+
+    req = Libc.malloc(_sizeof_uv_fs)
+    try
+        ret = ccall(:uv_fs_mkdtemp, Int32,
+                    (Ptr{Void}, Ptr{Void}, Cstring, Ptr{Void}),
+                    eventloop(), req, tpath, C_NULL)
+        if ret < 0
+            ccall(:uv_fs_req_cleanup, Void, (Ptr{Void},), req)
+            uv_error("mktempdir", ret)
+        end
+        path = unsafe_string(ccall(:jl_uv_fs_t_path, Ptr{Cchar}, (Ptr{Void},), req))
+        ccall(:uv_fs_req_cleanup, Void, (Ptr{Void},), req)
+        return path
+    finally
+        Libc.free(req)
+    end
+end
 
 """
     mktemp(f::Function, parent=tempdir())
@@ -381,13 +393,14 @@ function mktemp(fn::Function, parent=tempdir())
 end
 
 """
-    mktempdir(f::Function, parent=tempdir())
+    mktempdir(f::Function, parent=tempdir(); prefix="$(repr(temp_prefix))")
 
-Apply the function `f` to the result of [`mktempdir(parent)`](@ref) and remove the
+Apply the function `f` to the result of [`mktempdir(parent; prefix)`](@ref) and remove the
 temporary directory upon completion.
+An optional `prefix` to the directory name can be provided.
 """
-function mktempdir(fn::Function, parent=tempdir())
-    tmpdir = mktempdir(parent)
+function mktempdir(fn::Function, parent=tempdir(); prefix=temp_prefix)
+    tmpdir = mktempdir(parent; prefix=prefix)
     try
         fn(tmpdir)
     finally

src/sys.c

@@ -116,6 +116,7 @@ JL_DLLEXPORT int32_t jl_nb_available(ios_t *s)
 JL_DLLEXPORT int jl_sizeof_uv_fs_t(void) { return sizeof(uv_fs_t); }
 JL_DLLEXPORT void jl_uv_fs_req_cleanup(uv_fs_t *req) { uv_fs_req_cleanup(req); }
 JL_DLLEXPORT char *jl_uv_fs_t_ptr(uv_fs_t *req) { return (char*)req->ptr; }
+JL_DLLEXPORT char *jl_uv_fs_t_path(uv_fs_t *req) { return (char*)req->path; }
 JL_DLLEXPORT int jl_uv_fs_result(uv_fs_t *f) { return f->result; }
 
 // --- stat ---

test/file.jl

@@ -1183,3 +1183,80 @@ if !Sys.iswindows()
         test_22566()
     end
 end  # !Sys.iswindows
+
+function test_22922()
+    def_prefix = "jl_"
+    tst_prefix = "ABCDEF"
+    mktempdir() do tmpdir
+        filename = basename(tmpdir)
+        @test startswith(filename, def_prefix)
+    end
+    mktempdir(; prefix=tst_prefix) do tmpdir
+        filename = basename(tmpdir)
+        @test startswith(filename, tst_prefix)
+    end
+    # Special character prefix tests
+    tst_prefix="#!@%^&()"
+    mktempdir(; prefix=tst_prefix) do tmpdir
+        filename = basename(tmpdir)
+        @test startswith(filename, tst_prefix)
+    end
+
+    # Behavioral differences across OS types
+    if Sys.iswindows()
+        @test_throws Base.UVError mktempdir(; prefix="*")
+        @test_throws Base.UVError mktempdir(; prefix="cdcdccd/")
+
+        # The API accepts "c:/ and c:\\" as valid prefixes.
+        # The parent directory is ignored in that case.
+        # The temp directory created is of form "C:\\XXXXXX"
+        mktempdir("C:\\dir_notexisting"; prefix=tempdir()) do tmpdir
+            @test startswith(tmpdir, tempdir())
+            @test isdir(tmpdir)
+            filename = basename(tmpdir)
+            @test length(filename) == 6
+        end
+
+        # Although, underlying directory created is of type c:\\xxx\\yyy\\..., the returned
+        # directory name by the API is in the format as specified in the prefix
+        # parameter.
+        mktempdir("C:/dir_notexisting"; prefix=replace(tempdir(), '\\', '/')) do tmpdir
+            @test startswith(tmpdir, replace(tempdir(), '\\', '/'))
+            @test !startswith(tmpdir, tempdir())
+            @test isdir(tmpdir)
+            filename = basename(tmpdir)
+            @test length(filename) == 6
+        end
+    else
+        # '/' is accepted in a prefix but depends on the overall path and permissions.
+        # A carefully crafted parent directory and prefix combination can actually
+        # create a directory as the example below.
+        # The file created will be of format "/tmp/XXXXXX"
+        mktempdir(; prefix="/") do tmpdir
+            @test startswith(tmpdir, "/tmp/")
+            filename = basename(tmpdir)
+            @test length(filename) == 6
+        end
+
+        mktempdir(; prefix="////abc") do tmpdir
+            @test startswith(tmpdir, "/tmp/")
+            filename = basename(tmpdir)
+            @test length(filename) == 9
+        end
+
+        mktempdir("/"; prefix="tmp/") do tmpdir
+            @test startswith(tmpdir, "/tmp/")
+            filename = basename(tmpdir)
+            @test length(filename) == 6
+        end
+    end
+
+    # Unicode test
+    tst_prefix="∃x∀y"
+    mktempdir(; prefix=tst_prefix) do tmpdir
+        filename = basename(tmpdir)
+        @test startswith(filename, tst_prefix)
+    end
+end
+
+test_22922()