Down-integrate from internal code base.

[ci skip]

Change-Id: I9391c09640e0b0b2b21c45a97a1fc91814d95c5d

1 files changed, 228 insertions, 0 deletions

diff --git a/src/google/protobuf/util/internal/field_mask_utility.cc b/src/google/protobuf/util/internal/field_mask_utility.cc
new file mode 100644
index 00000000..92468959
--- /dev/null
+++ b/src/google/protobuf/util/internal/field_mask_utility.cc
@@ -0,0 +1,228 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/util/internal/field_mask_utility.h>
+
+#include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/stubs/status_macros.h>
+
+namespace google {
+
+namespace protobuf {
+namespace util {
+namespace converter {
+
+namespace {
+inline util::Status CallPathSink(PathSinkCallback path_sink,
+                                   StringPiece arg) {
+  return path_sink->Run(arg);
+}
+
+util::Status CreatePublicError(util::error::Code code,
+                                 const string& message) {
+  return util::Status(code, message);
+}
+
+// Appends a FieldMask path segment to a prefix.
+string AppendPathSegmentToPrefix(StringPiece prefix, StringPiece segment) {
+  if (prefix.empty()) {
+    return segment.ToString();
+  }
+  if (segment.empty()) {
+    return prefix.ToString();
+  }
+  // If the segment is a map key, appends it to the prefix without the ".".
+  if (segment.starts_with("[\"")) {
+    return StrCat(prefix, segment);
+  }
+  return StrCat(prefix, ".", segment);
+}
+
+}  // namespace
+
+string ConvertFieldMaskPath(const StringPiece path,
+                            ConverterCallback converter) {
+  string result;
+  result.reserve(path.size() << 1);
+
+  bool is_quoted = false;
+  bool is_escaping = false;
+  int current_segment_start = 0;
+
+  // Loops until 1 passed the end of the input to make handling the last
+  // segment easier.
+  for (size_t i = 0; i <= path.size(); ++i) {
+    // Outputs quoted string as-is.
+    if (is_quoted) {
+      if (i == path.size()) {
+        break;
+      }
+      result.push_back(path[i]);
+      if (is_escaping) {
+        is_escaping = false;
+      } else if (path[i] == '\\') {
+        is_escaping = true;
+      } else if (path[i] == '\"') {
+        current_segment_start = i + 1;
+        is_quoted = false;
+      }
+      continue;
+    }
+    if (i == path.size() || path[i] == '.' || path[i] == '(' ||
+        path[i] == ')' || path[i] == '\"') {
+      result += converter(
+          path.substr(current_segment_start, i - current_segment_start));
+      if (i < path.size()) {
+        result.push_back(path[i]);
+      }
+      current_segment_start = i + 1;
+    }
+    if (i < path.size() && path[i] == '\"') {
+      is_quoted = true;
+    }
+  }
+  return result;
+}
+
+util::Status DecodeCompactFieldMaskPaths(StringPiece paths,
+                                           PathSinkCallback path_sink) {
+  stack<string> prefix;
+  int length = paths.length();
+  int previous_position = 0;
+  bool in_map_key = false;
+  bool is_escaping = false;
+  // Loops until 1 passed the end of the input to make the handle of the last
+  // segment easier.
+  for (int i = 0; i <= length; ++i) {
+    if (i != length) {
+      // Skips everything in a map key until we hit the end of it, which is
+      // marked by an un-escaped '"' immediately followed by a ']'.
+      if (in_map_key) {
+        if (is_escaping) {
+          is_escaping = false;
+          continue;
+        }
+        if (paths[i] == '\\') {
+          is_escaping = true;
+          continue;
+        }
+        if (paths[i] != '\"') {
+          continue;
+        }
+        // Un-escaped '"' must be followed with a ']'.
+        if (i >= length - 1 || paths[i + 1] != ']') {
+          return CreatePublicError(
+              util::error::INVALID_ARGUMENT,
+              StrCat("Invalid FieldMask '", paths,
+                     "'. Map keys should be represented as [\"some_key\"]."));
+        }
+        // The end of the map key ("\"]") has been found.
+        in_map_key = false;
+        // Skips ']'.
+        i++;
+        // Checks whether the key ends at the end of a path segment.
+        if (i < length - 1 && paths[i + 1] != '.' && paths[i + 1] != ',' &&
+            paths[i + 1] != ')' && paths[i + 1] != '(') {
+          return CreatePublicError(
+              util::error::INVALID_ARGUMENT,
+              StrCat("Invalid FieldMask '", paths,
+                     "'. Map keys should be at the end of a path segment."));
+        }
+        is_escaping = false;
+        continue;
+      }
+
+      // We are not in a map key, look for the start of one.
+      if (paths[i] == '[') {
+        if (i >= length - 1 || paths[i + 1] != '\"') {
+          return CreatePublicError(
+              util::error::INVALID_ARGUMENT,
+              StrCat("Invalid FieldMask '", paths,
+                     "'. Map keys should be represented as [\"some_key\"]."));
+        }
+        // "[\"" starts a map key.
+        in_map_key = true;
+        i++;  // Skips the '\"'.
+        continue;
+      }
+      // If the current character is not a special character (',', '(' or ')'),
+      // continue to the next.
+      if (paths[i] != ',' && paths[i] != ')' && paths[i] != '(') {
+        continue;
+      }
+    }
+    // Gets the current segment - sub-string between previous position (after
+    // '(', ')', ',', or the beginning of the input) and the current position.
+    StringPiece segment =
+        paths.substr(previous_position, i - previous_position);
+    string current_prefix = prefix.empty() ? "" : prefix.top();
+
+    if (i < length && paths[i] == '(') {
+      // Builds a prefix and save it into the stack.
+      prefix.push(AppendPathSegmentToPrefix(current_prefix, segment));
+    } else if (!segment.empty()) {
+      // When the current charactor is ')', ',' or the current position has
+      // passed the end of the input, builds and outputs a new paths by
+      // concatenating the last prefix with the current segment.
+      RETURN_IF_ERROR(CallPathSink(
+          path_sink, AppendPathSegmentToPrefix(current_prefix, segment)));
+    }
+
+    // Removes the last prefix after seeing a ')'.
+    if (i < length && paths[i] == ')') {
+      if (prefix.empty()) {
+        return CreatePublicError(
+            util::error::INVALID_ARGUMENT,
+            StrCat("Invalid FieldMask '", paths,
+                   "'. Cannot find matching '(' for all ')'."));
+      }
+      prefix.pop();
+    }
+    previous_position = i + 1;
+  }
+  if (in_map_key) {
+    return CreatePublicError(
+        util::error::INVALID_ARGUMENT,
+        StrCat("Invalid FieldMask '", paths,
+               "'. Cannot find matching ']' for all '['."));
+  }
+  if (!prefix.empty()) {
+    return CreatePublicError(
+        util::error::INVALID_ARGUMENT,
+        StrCat("Invalid FieldMask '", paths,
+               "'. Cannot find matching ')' for all '('."));
+  }
+  return util::Status::OK;
+}
+
+}  // namespace converter
+}  // namespace util
+}  // namespace protobuf
+}  // namespace google