Move two generic string split functions from sync API to their own API in base/string_split.

base/string_split.cc

+// Copyright (c) 2009 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.
+
+#include "base/string_split.h"
+
+#include "base/string_util.h"
+
+namespace base {
+
+bool SplitStringIntoKeyValues(
+    const std::string& line,
+    char key_value_delimiter,
+    std::string* key, std::vector<std::string>* values) {
+  key->clear();
+  values->clear();
+
+  // find the key string
+  size_t end_key_pos = line.find_first_of(key_value_delimiter);
+  if (end_key_pos == std::string::npos) {
+    DLOG(INFO) << "cannot parse key from line: " << line;
+    return false;    // no key
+  }
+  key->assign(line, 0, end_key_pos);
+
+  // find the values string
+  std::string remains(line, end_key_pos, line.size() - end_key_pos);
+  size_t begin_values_pos = remains.find_first_not_of(key_value_delimiter);
+  if (begin_values_pos == std::string::npos) {
+    DLOG(INFO) << "cannot parse value from line: " << line;
+    return false;   // no value
+  }
+  std::string values_string(remains, begin_values_pos,
+                            remains.size() - begin_values_pos);
+
+  // construct the values vector
+  values->push_back(values_string);
+  return true;
+}
+
+bool SplitStringIntoKeyValuePairs(
+    const std::string& line,
+    char key_value_delimiter,
+    char key_value_pair_delimiter,
+    std::vector<std::pair<std::string, std::string> >* kv_pairs) {
+  kv_pairs->clear();
+
+  std::vector<std::string> pairs;
+  SplitString(line, key_value_pair_delimiter, &pairs);
+
+  bool success = true;
+  for (size_t i = 0; i < pairs.size(); ++i) {
+    std::string key;
+    std::vector<std::string> value;
+    if (!SplitStringIntoKeyValues(pairs[i],
+                                  key_value_delimiter,
+                                  &key, &value)) {
+      // Don't return here, to allow for keys without associated
+      // values; just record that our split failed.
+      success = false;
+    }
+    DCHECK_LE(value.size(), 1U);
+    kv_pairs->push_back(make_pair(key, value.empty()? "" : value[0]));
+  }
+  return success;
+}
+
+}  // namespace base