create errno policies for simulating errors. closes #107

README.md

@@ -73,6 +73,7 @@ Filesystem calls are broken up into 3 categories: **action**, **create**, **sear
 | lfs (least free space) | Pick the path with least available space but more than **minfreespace**. |
 | rand (random) | Pick an existing destination at random. |
 | all | Applies action to all found. For searches it will behave like first found **ff**. |
+| enosys, einval, enotsup, exdev, erofs | Exclusively return `-1` with `errno` set to the respective value. Useful for debugging other applications' behavior to errors. |
 
 #### Defaults ####
 

src/policy.cpp

@@ -36,7 +36,12 @@ namespace mergerfs
     buildvector<Policy,true>
     (POLICY(invalid))
     (POLICY(all))
+    (POLICY(einval))
+    (POLICY(enosys))
+    (POLICY(enotsup))
     (POLICY(epmfs))
+    (POLICY(erofs))
+    (POLICY(exdev))
     (POLICY(ff))
     (POLICY(ffwp))
     (POLICY(fwfs))
@@ -47,16 +52,23 @@ namespace mergerfs
 
   const Policy * const Policy::policies = &_policies_[1];
 
-  const Policy &Policy::invalid = Policy::policies[Policy::Enum::invalid];
-  const Policy &Policy::all     = Policy::policies[Policy::Enum::all];
-  const Policy &Policy::epmfs   = Policy::policies[Policy::Enum::epmfs];
-  const Policy &Policy::ff      = Policy::policies[Policy::Enum::ff];
-  const Policy &Policy::ffwp    = Policy::policies[Policy::Enum::ffwp];
-  const Policy &Policy::fwfs    = Policy::policies[Policy::Enum::fwfs];
-  const Policy &Policy::lfs     = Policy::policies[Policy::Enum::lfs];
-  const Policy &Policy::mfs     = Policy::policies[Policy::Enum::mfs];
-  const Policy &Policy::newest  = Policy::policies[Policy::Enum::newest];
-  const Policy &Policy::rand    = Policy::policies[Policy::Enum::rand];
+#define CONST_POLICY(X) const Policy &Policy::X = Policy::policies[Policy::Enum::X]
+
+  CONST_POLICY(invalid);
+  CONST_POLICY(all);
+  CONST_POLICY(einval);
+  CONST_POLICY(enosys);
+  CONST_POLICY(enotsup);
+  CONST_POLICY(epmfs);
+  CONST_POLICY(erofs);
+  CONST_POLICY(exdev);
+  CONST_POLICY(ff);
+  CONST_POLICY(ffwp);
+  CONST_POLICY(fwfs);
+  CONST_POLICY(lfs);
+  CONST_POLICY(mfs);
+  CONST_POLICY(newest);
+  CONST_POLICY(rand);
 
   const Policy&
   Policy::find(const std::string &str)

src/policy.hpp

@@ -45,7 +45,12 @@ namespace mergerfs
           invalid = -1,
           BEGIN   = 0,
           all     = BEGIN,
+          einval,
+          enosys,
+          enotsup,
           epmfs,
+          erofs,
+          exdev,
           ff,
           ffwp,
           fwfs,
@@ -120,12 +125,17 @@ namespace mergerfs
         const Ptr func;
       };
 
-      static int invalid(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int all(CType,cstrvec&,cstring&,csize_t,strvec&);
+      static int einval(CType,cstrvec&,cstring&,csize_t,strvec&);
+      static int enosys(CType,cstrvec&,cstring&,csize_t,strvec&);
+      static int enotsup(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int epmfs(CType,cstrvec&,cstring&,csize_t,strvec&);
+      static int erofs(CType,cstrvec&,cstring&,csize_t,strvec&);
+      static int exdev(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int ff(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int ffwp(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int fwfs(CType,cstrvec&,cstring&,csize_t,strvec&);
+      static int invalid(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int lfs(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int mfs(CType,cstrvec&,cstring&,csize_t,strvec&);
       static int newest(CType,cstrvec&,cstring&,csize_t,strvec&);
@@ -183,7 +193,11 @@ namespace mergerfs
 
     static const Policy &invalid;
     static const Policy &all;
+    static const Policy &enosys;
+    static const Policy &enotsup;
     static const Policy &epmfs;
+    static const Policy &erofs;
+    static const Policy &exdev;
     static const Policy &ff;
     static const Policy &ffwp;
     static const Policy &fwfs;

src/policy_einval.cpp

@@ -0,0 +1,46 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+#include <errno.h>
+
+#include <string>
+#include <vector>
+
+#include "policy.hpp"
+
+using std::string;
+using std::vector;
+
+namespace mergerfs
+{
+  int
+  Policy::Func::einval(const Category::Enum::Type  type,
+                       const vector<string>       &basepaths,
+                       const string               &fusepath,
+                       const size_t                minfreespace,
+                       vector<string>             &paths)
+  {
+    return (errno=EINVAL,-1);
+  }
+}

src/policy_enosys.cpp

@@ -0,0 +1,46 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+#include <errno.h>
+
+#include <string>
+#include <vector>
+
+#include "policy.hpp"
+
+using std::string;
+using std::vector;
+
+namespace mergerfs
+{
+  int
+  Policy::Func::enosys(const Category::Enum::Type  type,
+                       const vector<string>       &basepaths,
+                       const string               &fusepath,
+                       const size_t                minfreespace,
+                       vector<string>             &paths)
+  {
+    return (errno=ENOSYS,-1);
+  }
+}

src/policy_enotsup.cpp

@@ -0,0 +1,46 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+#include <errno.h>
+
+#include <string>
+#include <vector>
+
+#include "policy.hpp"
+
+using std::string;
+using std::vector;
+
+namespace mergerfs
+{
+  int
+  Policy::Func::enotsup(const Category::Enum::Type  type,
+                        const vector<string>       &basepaths,
+                        const string               &fusepath,
+                        const size_t                minfreespace,
+                        vector<string>             &paths)
+  {
+    return (errno=ENOTSUP,-1);
+  }
+}

src/policy_erofs.cpp

@@ -0,0 +1,46 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+#include <errno.h>
+
+#include <string>
+#include <vector>
+
+#include "policy.hpp"
+
+using std::string;
+using std::vector;
+
+namespace mergerfs
+{
+  int
+  Policy::Func::erofs(const Category::Enum::Type  type,
+                      const vector<string>       &basepaths,
+                      const string               &fusepath,
+                      const size_t                minfreespace,
+                      vector<string>             &paths)
+  {
+    return (errno=EROFS,-1);
+  }
+}

src/policy_exdev.cpp

@@ -0,0 +1,46 @@
+/*
+   The MIT License (MIT)
+
+   Copyright (c) 2014 Antonio SJ Musumeci <trapexit@spawn.link>
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+#include <errno.h>
+
+#include <string>
+#include <vector>
+
+#include "policy.hpp"
+
+using std::string;
+using std::vector;
+
+namespace mergerfs
+{
+  int
+  Policy::Func::exdev(const Category::Enum::Type  type,
+                      const vector<string>       &basepaths,
+                      const string               &fusepath,
+                      const size_t                minfreespace,
+                      vector<string>             &paths)
+  {
+    return (errno=EXDEV,-1);
+  }
+}