Move common file path related methods between chrome & content to file_util. I reduced the 4 methods into 3 by only having one GetUniquePathNumber which takes an optional suffix.

BUG=98716
Review URL: https://chromiumcodereview.appspot.com/9316004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119984 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 36 insertions, 0 deletions

diff --git a/base/file_util.cc b/base/file_util.cc
index dc186d9..8f67cc3 100644
--- a/base/file_util.cc
+++ b/base/file_util.cc
@@ -13,6 +13,7 @@
 
 #include "base/file_path.h"
 #include "base/logging.h"
+#include "base/stringprintf.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ -21,6 +22,13 @@ namespace {
 
 const FilePath::CharType kExtensionSeparator = FILE_PATH_LITERAL('.');
 
+// The maximum number of 'uniquified' files we will try to create.
+// This is used when the filename we're trying to download is already in use,
+// so we create a new unique filename by appending " (nnn)" before the
+// extension, where 1 <= nnn <= kMaxUniqueFiles.
+// Also used by code that cleans up said files.
+static const int kMaxUniqueFiles = 100;
+
 }  // namespace
 
 namespace file_util {
@@ -237,6 +245,27 @@ bool TruncateFile(FILE* file) {
   return true;
 }
 
+int GetUniquePathNumber(
+    const FilePath& path,
+    const FilePath::StringType& suffix) {
+  bool have_suffix = !suffix.empty();
+  if (!PathExists(path) &&
+      (!have_suffix || !PathExists(FilePath(path.value() + suffix)))) {
+    return 0;
+  }
+
+  FilePath new_path;
+  for (int count = 1; count <= kMaxUniqueFiles; ++count) {
+    new_path = path.InsertBeforeExtensionASCII(StringPrintf(" (%d)", count));
+    if (!PathExists(new_path) &&
+        (!have_suffix || !PathExists(FilePath(new_path.value() + suffix)))) {
+      return count;
+    }
+  }
+
+  return -1;
+}
+
 bool ContainsPath(const FilePath &parent, const FilePath& child) {
   FilePath abs_parent = FilePath(parent);
   FilePath abs_child = FilePath(child);
diff --git a/base/file_util.h b/base/file_util.h
index 384f394..53264c1 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -388,6 +388,13 @@ BASE_EXPORT bool GetCurrentDirectory(FilePath* path);
 // Sets the current working directory for the process.
 BASE_EXPORT bool SetCurrentDirectory(const FilePath& path);
 
+// Attempts to find a number that can be appended to the |path| to make it
+// unique. If |path| does not exist, 0 is returned.  If it fails to find such
+// a number, -1 is returned. If |suffix| is not empty, also checks the
+// existence of it with the given suffix.
+BASE_EXPORT int GetUniquePathNumber(const FilePath& path,
+                                    const FilePath::StringType& suffix);
+
 #if defined(OS_POSIX)
 // Test that |path| can only be changed by a given user and members of
 // a given set of groups.