Move utf_offset_string_conversions and utf_string_conversion_utils to strings.

Review URL: https://codereview.chromium.org/12087115

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181183 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 93 insertions, 0 deletions

diff --git a/base/strings/utf_offset_string_conversions.h b/base/strings/utf_offset_string_conversions.h
new file mode 100644
index 0000000..98f29b9
--- /dev/null
+++ b/base/strings/utf_offset_string_conversions.h
@@ -0,0 +1,93 @@
+// Copyright (c) 2011 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.
+
+#ifndef BASE_STRINGS_UTF_OFFSET_STRING_CONVERSIONS_H_
+#define BASE_STRINGS_UTF_OFFSET_STRING_CONVERSIONS_H_
+
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/string16.h"
+#include "base/string_piece.h"
+
+namespace base {
+
+// Like the conversions in utf_string_conversions.h, but also takes one or more
+// offsets (|offset[s]_for_adjustment|) into the source strings, each offset
+// will be adjusted to point at the same logical place in the result strings.
+// If this isn't possible because an offset points past the end of the source
+// strings or into the middle of a multibyte sequence, the offending offset will
+// be set to string16::npos. |offset[s]_for_adjustment| may be NULL.
+BASE_EXPORT bool UTF8ToUTF16AndAdjustOffset(const char* src,
+                                            size_t src_len,
+                                            string16* output,
+                                            size_t* offset_for_adjustment);
+BASE_EXPORT bool UTF8ToUTF16AndAdjustOffsets(
+    const char* src,
+    size_t src_len,
+    string16* output,
+    std::vector<size_t>* offsets_for_adjustment);
+
+BASE_EXPORT string16 UTF8ToUTF16AndAdjustOffset(const base::StringPiece& utf8,
+                                                size_t* offset_for_adjustment);
+BASE_EXPORT string16 UTF8ToUTF16AndAdjustOffsets(
+    const base::StringPiece& utf8,
+    std::vector<size_t>* offsets_for_adjustment);
+
+BASE_EXPORT std::string UTF16ToUTF8AndAdjustOffset(
+    const base::StringPiece16& utf16,
+    size_t* offset_for_adjustment);
+BASE_EXPORT std::string UTF16ToUTF8AndAdjustOffsets(
+    const base::StringPiece16& utf16,
+    std::vector<size_t>* offsets_for_adjustment);
+
+// Limiting function callable by std::for_each which will replace any value
+// which is equal to or greater than |limit| with npos.
+template <typename T>
+struct LimitOffset {
+  explicit LimitOffset(size_t limit)
+    : limit_(limit) {}
+
+  void operator()(size_t& offset) {
+    if (offset >= limit_)
+      offset = T::npos;
+  }
+
+  size_t limit_;
+};
+
+// Stack object which, on destruction, will update a vector of offsets based on
+// any supplied adjustments.  To use, declare one of these, providing the
+// address of the offset vector to adjust.  Then Add() any number of Adjustments
+// (each Adjustment gives the |original_offset| of a substring and the lengths
+// of the substring before and after transforming).  When the OffsetAdjuster
+// goes out of scope, all the offsets in the provided vector will be updated.
+class BASE_EXPORT OffsetAdjuster {
+ public:
+  struct BASE_EXPORT Adjustment {
+    Adjustment(size_t original_offset,
+               size_t original_length,
+               size_t output_length);
+
+    size_t original_offset;
+    size_t original_length;
+    size_t output_length;
+  };
+
+  explicit OffsetAdjuster(std::vector<size_t>* offsets_for_adjustment);
+  ~OffsetAdjuster();
+
+  void Add(const Adjustment& adjustment);
+
+ private:
+  void AdjustOffset(std::vector<size_t>::iterator offset);
+
+  std::vector<size_t>* offsets_for_adjustment_;
+  std::vector<Adjustment> adjustments_;
+};
+
+}  // namespace base
+
+#endif  // BASE_STRINGS_UTF_OFFSET_STRING_CONVERSIONS_H_