Improve cdc_fuse_fs and path (#2)

Improve cdc_fuse_fs and path

Improves the error handling in path so that std:error_codes are not
assumed to be of system category, and also that their messages are
displayed. Also improves debug messages in GameletComponent.

common/BUILD

@@ -66,6 +66,7 @@ cc_library(
     deps = [
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:str_format",
     ],
 )
 

common/dir_iter.cc

@@ -221,8 +221,8 @@ bool DirectoryIterator::Open(const std::string& path,
     impl_->PushDir(dir, path::BaseName(path));
     return true;
   }
-  impl_->SetStatus(ErrnoToCanonicalStatus(
-      errno, absl::StrFormat("Failed to open directory '%s'", path)));
+  impl_->SetStatus(
+      ErrnoToCanonicalStatus(errno, "Failed to open directory '%s'", path));
   return false;
 }
 
@@ -259,7 +259,7 @@ bool DirectoryIterator::NextEntry(DirectoryEntry* entry) {
           // Ignore access errors and proceed.
         } else {
           impl_->SetStatus(ErrnoToCanonicalStatus(
-              errno, absl::StrFormat("Failed to open directory '%s'", subdir)));
+              errno, "Failed to open directory '%s'", subdir));
           return false;
         }
       }
@@ -278,8 +278,7 @@ bool DirectoryIterator::NextEntry(DirectoryEntry* entry) {
 
   if (errno) {
     impl_->SetStatus(ErrnoToCanonicalStatus(
-        errno, absl::StrFormat("Failed to iterate over directory '%s'",
-                               impl_->DirsPath())));
+        errno, "Failed to iterate over directory '%s'", impl_->DirsPath()));
   }
   return false;
 }

common/errno_mapping.cc

@@ -16,8 +16,6 @@
 
 #include <errno.h>
 
-#include <string>
-
 namespace cdc_ft {
 
 absl::StatusCode ErrnoToCanonicalCode(int error_number) {
@@ -160,10 +158,4 @@ absl::StatusCode ErrnoToCanonicalCode(int error_number) {
   }
 }
 
-absl::Status ErrnoToCanonicalStatus(int error_number,
-                                    absl::string_view message) {
-  return absl::Status(ErrnoToCanonicalCode(error_number),
-                      absl::StrCat(message, ": ", strerror(error_number)));
-}
-
 }  // namespace cdc_ft

common/errno_mapping.h

@@ -17,8 +17,10 @@
 #ifndef COMMON_ERRNO_MAPPING_H_
 #define COMMON_ERRNO_MAPPING_H_
 
+#include <string>
+
 #include "absl/status/status.h"
-#include "absl/strings/string_view.h"
+#include "absl/strings/str_format.h"
 
 namespace cdc_ft {
 
@@ -26,8 +28,27 @@ namespace cdc_ft {
 absl::StatusCode ErrnoToCanonicalCode(int error_number);
 
 // Creates a status by converting the errno |error_number| to an absl code.
+template <typename... Args>
 absl::Status ErrnoToCanonicalStatus(int error_number,
-                                    absl::string_view message);
+                                    const absl::FormatSpec<Args...>& format,
+                                    Args... args) {
+  if (error_number == 0) return absl::OkStatus();
+  std::string msg = absl::StrFormat(format, args...);
+  return absl::Status(ErrnoToCanonicalCode(error_number),
+                      absl::StrCat(msg, ": ", strerror(error_number)));
+}
+
+template <typename... Args>
+absl::Status ErrorCodeToCanonicalStatus(const std::error_code& code,
+                                        const absl::FormatSpec<Args...>& format,
+                                        Args... args) {
+  if (!code) return absl::OkStatus();
+  std::string msg = absl::StrFormat(format, args...);
+  absl::StatusCode absl_code = code.category() == std::system_category()
+                                   ? ErrnoToCanonicalCode(code.value())
+                                   : absl::StatusCode::kUnknown;
+  return absl::Status(absl_code, absl::StrCat(msg, ": ", code.message()));
+}
 
 }  // namespace cdc_ft
 

common/path.cc

@@ -470,8 +470,7 @@ absl::StatusOr<FILE*> OpenFile(const std::string& path, const char* mode) {
 #endif
   if (!file) {
     int err = errno;
-    return ErrnoToCanonicalStatus(
-        err, absl::StrFormat("Failed to open file '%s'", path));
+    return ErrnoToCanonicalStatus(err, "Failed to open file '%s'", path);
   }
   return file;
 }
@@ -914,8 +913,7 @@ absl::Status GetStats(const std::string& path, Stats* stats) {
   if (!result) {
     int err = errno;
     *stats = Stats();
-    return ErrnoToCanonicalStatus(err,
-                                  absl::StrFormat("Failed to stat '%s'", path));
+    return ErrnoToCanonicalStatus(err, "Failed to stat '%s'", path);
   }
 
   stats->mode = os_stats.st_mode;
@@ -973,14 +971,9 @@ absl::Status CreateSymlink(const std::string& target,
     std::filesystem::create_directory_symlink(target_u8, link_path_u8,
                                               error_code);
   }
-  if (error_code) {
-    assert(error_code.category() == std::system_category());
-    return ErrnoToCanonicalStatus(
-        error_code.value(),
-        absl::StrFormat("Failed to create symlink '%s' with target '%s'",
-                        link_path, target));
-  }
-  return absl::OkStatus();
+  return ErrorCodeToCanonicalStatus(
+      error_code, "Failed to create symlink '%s' with target '%s'", link_path,
+      target);
 }
 
 absl::StatusOr<std::string> GetSymlinkTarget(const std::string& link_path) {
@@ -989,9 +982,8 @@ absl::StatusOr<std::string> GetSymlinkTarget(const std::string& link_path) {
   std::filesystem::path symlink_target =
       std::filesystem::read_symlink(link_path_u8, error_code);
   if (error_code) {
-    return ErrnoToCanonicalStatus(
-        error_code.value(),
-        absl::StrFormat("Failed to read symlink '%s'", link_path));
+    return ErrorCodeToCanonicalStatus(error_code, "Failed to read symlink '%s'",
+                                      link_path);
   }
   return symlink_target.u8string();
 }
@@ -1014,26 +1006,16 @@ bool Exists(const std::string& path) {
 absl::Status CreateDir(const std::string& path) {
   std::error_code error_code;
   std::filesystem::create_directory(std::filesystem::u8path(path), error_code);
-  if (error_code) {
-    assert(error_code.category() == std::system_category());
-    return ErrnoToCanonicalStatus(
-        error_code.value(),
-        absl::StrFormat("Failed to create directory '%s'", path));
-  }
-  return absl::OkStatus();
+  return ErrorCodeToCanonicalStatus(error_code,
+                                    "Failed to create directory '%s'", path);
 }
 
 absl::Status CreateDirRec(const std::string& path) {
   std::error_code error_code;
   std::filesystem::create_directories(std::filesystem::u8path(path),
                                       error_code);
-  if (error_code) {
-    assert(error_code.category() == std::system_category());
-    return ErrnoToCanonicalStatus(
-        error_code.value(),
-        absl::StrFormat("Failed to create directory '%s'", path));
-  }
-  return absl::OkStatus();
+  return ErrorCodeToCanonicalStatus(error_code,
+                                    "Failed to create directory '%s'", path);
 }
 
 absl::Status RenameFile(const std::string& from_path,