Added new ReadFileToString API with a max_size argument

base/file_util.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains utility functions for dealing with the local
 // filesystem.
 
 #ifndef BASE_FILE_UTIL_H_
 #define BASE_FILE_UTIL_H_
 
@@ skipping 115 matching lines @@
                                const FilePath& filename2);
 
 // Returns true if the contents of the two text files given are equal, false
 // otherwise.  This routine treats "\r\n" and "\n" as equivalent.
 BASE_EXPORT bool TextContentsEqual(const FilePath& filename1,
                                    const FilePath& filename2);
 
 // Read the file at |path| into |contents|, returning true on success.
 // This function fails if the |path| contains path traversal components ('..').
 // |contents| may be NULL, in which case this function is useful for its
-// side effect of priming the disk cache.
-// Useful for unit tests.
+// side effect of priming the disk cache, which is useful for unit tests.

[brettw, 2014/02/18 05:24:33]

Can you document that this replaces rather than appends, and that the buffer
will be cleared on failure?

[kaliamoorthi, 2014/02/18 11:50:50]

Done.

 BASE_EXPORT bool ReadFileToString(const FilePath& path, std::string* contents);
 
+// Read the file at |path| into |contents|, returning true on success.
+// This function has an additional check on the maximum size of the file.
+// When the file size is greater than |max_size|, the function reads |max_size|
+// bytes into |contents| and returns false.
+// This function fails if the |path| contains path traversal components ('..').
+// |contents| may be NULL, in which case this function is useful for its
+// side effect of priming the disk cache, which is useful for unit tests.
+BASE_EXPORT bool ReadFileToString(const FilePath& path,
+                                  std::string* contents,
+                                  size_t max_size);
+
 #if defined(OS_POSIX)
 
 // Read exactly |bytes| bytes from file descriptor |fd|, storing the result
 // in |buffer|. This function is protected against EINTR and partial reads.
 // Returns true iff |bytes| bytes have been successfully read from |fd|.
 BASE_EXPORT bool ReadFromFD(int fd, char* buffer, size_t bytes);
 
 // Creates a symbolic link at |symlink| pointing to |target|.  Returns
 // false on failure.
 BASE_EXPORT bool CreateSymbolicLink(const FilePath& target,
@@ skipping 306 matching lines @@
 // This function simulates Move(), but unlike Move() it works across volumes.
 // This function is not transactional.
 BASE_EXPORT bool CopyAndDeleteDirectory(const FilePath& from_path,
                                         const FilePath& to_path);
 #endif  // defined(OS_WIN)
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_FILE_UTIL_H_