diff options
author | Feng Xiao <xfxyjwf@gmail.com> | 2016-07-13 13:47:51 -0700 |
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committer | Feng Xiao <xfxyjwf@gmail.com> | 2016-07-13 13:48:40 -0700 |
commit | 9086d9643903c608ab015b0b7d903547a4e7b6f3 (patch) | |
tree | b47053ab6f6bde20b55c4fff4019c68a7c45545c /java/core/src/main/java/com/google/protobuf/CodedOutputStream.java | |
parent | 70c1ac756d3cd8fa04725f82f0ad1a30404c3bb3 (diff) |
Integrate from internal code base.
Diffstat (limited to 'java/core/src/main/java/com/google/protobuf/CodedOutputStream.java')
-rw-r--r-- | java/core/src/main/java/com/google/protobuf/CodedOutputStream.java | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java index 576a350f..4f5a9b77 100644 --- a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java +++ b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java @@ -145,6 +145,44 @@ public abstract class CodedOutputStream extends ByteOutput { } /** + * Configures serialization to be deterministic. + * + * <p>The deterministic serialization guarantees that for a given binary, equal (defined by the + * {@code equals()} methods in protos) messages will always be serialized to the same bytes. This + * implies: + * + * <ul> + * <li>repeated serialization of a message will return the same bytes + * <li>different processes of the same binary (which may be executing on different machines) will + * serialize equal messages to the same bytes. + * </ul> + * + * <p>Note the deterministic serialization is NOT canonical across languages; it is also unstable + * across different builds with schema changes due to unknown fields. Users who need canonical + * serialization, e.g. persistent storage in a canonical form, fingerprinting, etc, should define + * their own canonicalization specification and implement the serializer using reflection APIs + * rather than relying on this API. + * + * <p> Once set, the serializer will: (Note this is an implementation detail and may subject to + * change in the future) + * + * <ul> + * <li> sort map entries by keys in lexicographical order or numerical order. Note: For string + * keys, the order is based on comparing the Unicode value of each character in the strings. + * The order may be different from the deterministic serialization in other languages where + * maps are sorted on the lexicographical order of the UTF8 encoded keys. + * </ul> + */ + public final void useDeterministicSerialization() { + serializationDeterministic = true; + } + + boolean isSerializationDeterministic() { + return serializationDeterministic; + } + private boolean serializationDeterministic; + + /** * Create a new {@code CodedOutputStream} that writes to the given {@link ByteBuffer}. * * @deprecated the size parameter is no longer used since use of an internal buffer is useless |