migrate delimited messages functions to util package

3 files changed, 202 insertions, 0 deletions

diff --git a/src/google/protobuf/util/delimited_message_util.cc b/src/google/protobuf/util/delimited_message_util.cc
new file mode 100644
index 00000000..36e0118d
--- /dev/null
+++ b/src/google/protobuf/util/delimited_message_util.cc
@@ -0,0 +1,79 @@
+// Adapted from the patch of kenton@google.com (Kenton Varda)
+// See https://github.com/google/protobuf/pull/710 for details.
+
+#include <google/protobuf/util/delimited_message_util.h>
+
+namespace google {
+namespace protobuf {
+namespace util {
+
+bool SerializeDelimitedToFileDescriptor(const Message* message, int file_descriptor) {
+  io::FileOutputStream output(file_descriptor);
+  return SerializeDelimitedToZeroCopyStream(message, &output);
+}
+
+bool SerializeDelimitedToOstream(const Message* message, ostream* output) {
+  {
+    io::OstreamOutputStream zero_copy_output(output);
+    if (!SerializeDelimitedToZeroCopyStream(message, &zero_copy_output)) return false;
+  }
+  return output->good();
+}
+
+bool ParseDelimitedFromZeroCopyStream(MessageLite* message, io::ZeroCopyInputStream* input, bool* clean_eof) {
+  google::protobuf::io::CodedInputStream coded_input(input);
+  return ParseDelimitedFromCodedStream(message, &coded_input, clean_eof);
+}
+
+bool ParseDelimitedFromCodedStream(MessageLite* message, io::CodedInputStream* input, bool* clean_eof) {
+  if (clean_eof != NULL) *clean_eof = false;
+  int start = input->CurrentPosition();
+
+  // Read the size.
+  uint32 size;
+  if (!input->ReadVarint32(&size)) {
+    if (clean_eof != NULL) *clean_eof = input->CurrentPosition() == start;
+    return false;
+  }
+
+  // Tell the stream not to read beyond that size.
+  google::protobuf::io::CodedInputStream::Limit limit = input->PushLimit(size);
+
+  // Parse the message.
+  if (!message->MergeFromCodedStream(input)) return false;
+  if (!input->ConsumedEntireMessage()) return false;
+
+  // Release the limit.
+  input->PopLimit(limit);
+
+  return true;
+}
+
+bool SerializeDelimitedToZeroCopyStream(const MessageLite* message, io::ZeroCopyOutputStream* output) {
+  google::protobuf::io::CodedOutputStream coded_output(output);
+  return SerializeDelimitedToCodedStream(message, &coded_output);
+}
+
+bool SerializeDelimitedToCodedStream(const MessageLite* message, io::CodedOutputStream* output) {
+  // Write the size.
+  int size = message->ByteSize();
+  output->WriteVarint32(size);
+
+  // Write the content.
+  uint8* buffer = output->GetDirectBufferForNBytesAndAdvance(size);
+  if (buffer != NULL) {
+    // Optimization: The message fits in one buffer, so use the faster
+    // direct-to-array serialization path.
+    message->SerializeWithCachedSizesToArray(buffer);
+  } else {
+    // Slightly-slower path when the message is multiple buffers.
+    message->SerializeWithCachedSizes(output);
+    if (output->HadError()) return false;
+  }
+
+  return true;
+}
+
+}  // namespace util
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/util/delimited_message_util.h b/src/google/protobuf/util/delimited_message_util.h
new file mode 100644
index 00000000..970f4e92
--- /dev/null
+++ b/src/google/protobuf/util/delimited_message_util.h
@@ -0,0 +1,66 @@
+// Adapted from the patch of kenton@google.com (Kenton Varda)
+// See https://github.com/google/protobuf/pull/710 for details.
+
+#ifndef GOOGLE_PROTOBUF_UTIL_DELIMITED_MESSAGE_UTIL_H__
+#define GOOGLE_PROTOBUF_UTIL_DELIMITED_MESSAGE_UTIL_H__
+
+#include <ostream>
+
+#include <google/protobuf/message.h>
+#include <google/protobuf/io/coded_stream.h>
+#include <google/protobuf/io/zero_copy_stream_impl.h>
+
+namespace google {
+namespace protobuf {
+namespace util {
+
+// Write a single size-delimited message from the given stream. Delimited
+// format allows a single file or stream to contain multiple messages,
+// whereas normally writing multiple non-delimited messages to the same
+// stream would cause them to be merged. A delimited message is a varint
+// encoding the message size followed by a message of exactly that size.
+//
+// Note that if you want to *read* a delimited message from a file descriptor
+// or istream, you will need to construct an io::FileInputStream or
+// io::OstreamInputStream (implementations of io::ZeroCopyStream) and use the
+// MessageLite method ParseDelimitedFromZeroCopyStream(). You must then
+// continue to use the same ZeroCopyInputStream to read all further data from
+// the stream until EOF. This is because these ZeroCopyInputStream
+// implementations are buffered: they read a big chunk of data at a time,
+// then parse it. As a result, they may read past the end of the delimited
+// message. There is no way for them to push the extra data back into the
+// underlying source, so instead you must keep using the same stream object.
+bool SerializeDelimitedToFileDescriptor(const Message* message, int file_descriptor);
+
+bool SerializeDelimitedToOstream(const Message* message, ostream* output);
+
+// Read a single size-delimited message from the given stream. Delimited
+// format allows a single file or stream to contain multiple messages,
+// whereas normally parsing consumes the entire input. A delimited message
+// is a varint encoding the message size followed by a message of exactly
+// that size.
+//
+// If |clean_eof| is not NULL, then it will be set to indicate whether the
+// stream ended cleanly. That is, if the stream ends without this method
+// having read any data at all from it, then *clean_eof will be set true,
+// otherwise it will be set false. Note that these methods return false
+// on EOF, but they also return false on other errors, so |clean_eof| is
+// needed to distinguish a clean end from errors.
+bool ParseDelimitedFromZeroCopyStream(MessageLite* message, io::ZeroCopyInputStream* input, bool* clean_eof);
+
+bool ParseDelimitedFromCodedStream(MessageLite* message, io::CodedInputStream* input, bool* clean_eof);
+
+// Write a single size-delimited message from the given stream. Delimited
+// format allows a single file or stream to contain multiple messages,
+// whereas normally writing multiple non-delimited messages to the same
+// stream would cause them to be merged. A delimited message is a varint
+// encoding the message size followed by a message of exactly that size.
+bool SerializeDelimitedToZeroCopyStream(const MessageLite* message, io::ZeroCopyOutputStream* output);
+
+bool SerializeDelimitedToCodedStream(const MessageLite* message, io::CodedOutputStream* output);
+
+}  // namespace util
+}  // namespace protobuf
+}  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_UTIL_DELIMITED_MESSAGE_UTIL_H__
diff --git a/src/google/protobuf/util/delimited_message_util_test.cc b/src/google/protobuf/util/delimited_message_util_test.cc
new file mode 100644
index 00000000..0954773b
--- /dev/null
+++ b/src/google/protobuf/util/delimited_message_util_test.cc
@@ -0,0 +1,57 @@
+// Adapted from the patch of kenton@google.com (Kenton Varda)
+// See https://github.com/google/protobuf/pull/710 for details.
+
+#include <google/protobuf/util/delimited_message_util.h>
+
+#include <sstream>
+
+#include <google/protobuf/test_util.h>
+#include <google/protobuf/unittest.pb.h>
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+
+namespace google {
+namespace protobuf {
+namespace util {
+
+TEST(MessageTest, DelimitedMessages) {
+  stringstream stream;
+
+  {
+    protobuf_unittest::TestAllTypes message1;
+    TestUtil::SetAllFields(&message1);
+    EXPECT_TRUE(SerializeDelimitedToOstream(&message1, &stream));
+
+    protobuf_unittest::TestPackedTypes message2;
+    TestUtil::SetPackedFields(&message2);
+    EXPECT_TRUE(SerializeDelimitedToOstream(&message2, &stream));
+  }
+
+  {
+    bool clean_eof;
+    io::IstreamInputStream zstream(&stream);
+
+    protobuf_unittest::TestAllTypes message1;
+    clean_eof = true;
+    EXPECT_TRUE(ParseDelimitedFromZeroCopyStream(&message1,
+        &zstream, &clean_eof));
+    EXPECT_FALSE(clean_eof);
+    TestUtil::ExpectAllFieldsSet(message1);
+
+    protobuf_unittest::TestPackedTypes message2;
+    clean_eof = true;
+    EXPECT_TRUE(ParseDelimitedFromZeroCopyStream(&message2,
+        &zstream, &clean_eof));
+    EXPECT_FALSE(clean_eof);
+    TestUtil::ExpectPackedFieldsSet(message2);
+
+    clean_eof = false;
+    EXPECT_FALSE(ParseDelimitedFromZeroCopyStream(&message2,
+        &zstream, &clean_eof));
+    EXPECT_TRUE(clean_eof);
+  }
+}
+
+}  // namespace util
+}  // namespace protobuf
+}  // namespace google