blob: b22ace2e74de785e17e92730bcabc3a23f9c9136 [file] [log] [blame]
use std::any::Any;
use std::any::TypeId;
use std::fmt;
use std::io::Read;
use std::io::Write;
#[cfg(feature = "bytes")]
use bytes::Bytes;
use crate::clear::Clear;
use crate::error::ProtobufError;
use crate::error::ProtobufResult;
use crate::reflect::MessageDescriptor;
use crate::stream::with_coded_output_stream_to_bytes;
use crate::stream::CodedInputStream;
use crate::stream::CodedOutputStream;
use crate::stream::WithCodedInputStream;
use crate::stream::WithCodedOutputStream;
use crate::unknown::UnknownFields;
/// Trait implemented for all generated structs for protobuf messages.
///
/// Also, generated messages implement `Clone + Default + PartialEq`
pub trait Message: fmt::Debug + Clear + Any + Send + Sync {
/// Message descriptor for this message, used for reflection.
fn descriptor(&self) -> &'static MessageDescriptor;
/// True iff all required fields are initialized.
/// Always returns `true` for protobuf 3.
fn is_initialized(&self) -> bool;
/// Update this message object with fields read from given stream.
fn merge_from(&mut self, is: &mut CodedInputStream) -> ProtobufResult<()>;
/// Parse message from stream.
fn parse_from(is: &mut CodedInputStream) -> ProtobufResult<Self>
where
Self: Sized,
{
let mut r: Self = Message::new();
r.merge_from(is)?;
r.check_initialized()?;
Ok(r)
}
/// Write message to the stream.
///
/// Sizes of this messages and nested messages must be cached
/// by calling `compute_size` prior to this call.
fn write_to_with_cached_sizes(&self, os: &mut CodedOutputStream) -> ProtobufResult<()>;
/// Compute and cache size of this message and all nested messages
fn compute_size(&self) -> u32;
/// Get size previously computed by `compute_size`.
fn get_cached_size(&self) -> u32;
/// Write the message to the stream.
///
/// Results in error if message is not fully initialized.
fn write_to(&self, os: &mut CodedOutputStream) -> ProtobufResult<()> {
self.check_initialized()?;
// cache sizes
self.compute_size();
// TODO: reserve additional
self.write_to_with_cached_sizes(os)?;
Ok(())
}
/// Write the message to the stream prepending the message with message length
/// encoded as varint.
fn write_length_delimited_to(&self, os: &mut CodedOutputStream) -> ProtobufResult<()> {
let size = self.compute_size();
os.write_raw_varint32(size)?;
self.write_to_with_cached_sizes(os)?;
// TODO: assert we've written same number of bytes as computed
Ok(())
}
/// Write the message to the vec, prepend the message with message length
/// encoded as varint.
fn write_length_delimited_to_vec(&self, vec: &mut Vec<u8>) -> ProtobufResult<()> {
let mut os = CodedOutputStream::vec(vec);
self.write_length_delimited_to(&mut os)?;
os.flush()?;
Ok(())
}
/// Update this message object with fields read from given stream.
fn merge_from_bytes(&mut self, bytes: &[u8]) -> ProtobufResult<()> {
let mut is = CodedInputStream::from_bytes(bytes);
self.merge_from(&mut is)
}
/// Parse message from reader.
/// Parse stops on EOF or when error encountered.
fn parse_from_reader(reader: &mut dyn Read) -> ProtobufResult<Self>
where
Self: Sized,
{
let mut is = CodedInputStream::new(reader);
let r = Message::parse_from(&mut is)?;
is.check_eof()?;
Ok(r)
}
/// Parse message from byte array.
fn parse_from_bytes(bytes: &[u8]) -> ProtobufResult<Self>
where
Self: Sized,
{
let mut is = CodedInputStream::from_bytes(bytes);
let r = Message::parse_from(&mut is)?;
is.check_eof()?;
Ok(r)
}
/// Parse message from `Bytes` object.
/// Resulting message may share references to the passed bytes object.
#[cfg(feature = "bytes")]
fn parse_from_carllerche_bytes(bytes: &Bytes) -> ProtobufResult<Self>
where
Self: Sized,
{
let mut is = CodedInputStream::from_carllerche_bytes(bytes);
let r = Self::parse_from(&mut is)?;
is.check_eof()?;
Ok(r)
}
/// Check if all required fields of this object are initialized.
fn check_initialized(&self) -> ProtobufResult<()> {
if !self.is_initialized() {
Err(ProtobufError::message_not_initialized(
self.descriptor().name(),
))
} else {
Ok(())
}
}
/// Write the message to the writer.
fn write_to_writer(&self, w: &mut dyn Write) -> ProtobufResult<()> {
w.with_coded_output_stream(|os| self.write_to(os))
}
/// Write the message to bytes vec.
fn write_to_vec(&self, v: &mut Vec<u8>) -> ProtobufResult<()> {
v.with_coded_output_stream(|os| self.write_to(os))
}
/// Write the message to bytes vec.
fn write_to_bytes(&self) -> ProtobufResult<Vec<u8>> {
self.check_initialized()?;
let size = self.compute_size() as usize;
let mut v = Vec::with_capacity(size);
// skip zerofill
unsafe {
v.set_len(size);
}
{
let mut os = CodedOutputStream::bytes(&mut v);
self.write_to_with_cached_sizes(&mut os)?;
os.check_eof();
}
Ok(v)
}
/// Write the message to the writer, prepend the message with message length
/// encoded as varint.
fn write_length_delimited_to_writer(&self, w: &mut dyn Write) -> ProtobufResult<()> {
w.with_coded_output_stream(|os| self.write_length_delimited_to(os))
}
/// Write the message to the bytes vec, prepend the message with message length
/// encoded as varint.
fn write_length_delimited_to_bytes(&self) -> ProtobufResult<Vec<u8>> {
with_coded_output_stream_to_bytes(|os| self.write_length_delimited_to(os))
}
/// Get a reference to unknown fields.
fn get_unknown_fields<'s>(&'s self) -> &'s UnknownFields;
/// Get a mutable reference to unknown fields.
fn mut_unknown_fields<'s>(&'s mut self) -> &'s mut UnknownFields;
/// Get type id for downcasting.
fn type_id(&self) -> TypeId {
TypeId::of::<Self>()
}
/// View self as `Any`.
fn as_any(&self) -> &dyn Any;
/// View self as mutable `Any`.
fn as_any_mut(&mut self) -> &mut dyn Any {
panic!()
}
/// Convert boxed self to boxed `Any`.
fn into_any(self: Box<Self>) -> Box<dyn Any> {
panic!()
}
// Rust does not allow implementation of trait for trait:
// impl<M : Message> fmt::Debug for M {
// ...
// }
/// Create an empty message object.
///
///
/// ```
/// # use protobuf::Message;
/// # fn foo<MyMessage: Message>() {
/// let m = MyMessage::new();
/// # }
/// ```
fn new() -> Self
where
Self: Sized;
/// Get message descriptor for message type.
///
/// ```
/// # use protobuf::Message;
/// # fn foo<MyMessage: Message>() {
/// let descriptor = MyMessage::descriptor_static();
/// assert_eq!("MyMessage", descriptor.name());
/// # }
/// ```
fn descriptor_static() -> &'static MessageDescriptor
where
Self: Sized,
{
panic!(
"descriptor_static is not implemented for message, \
LITE_RUNTIME must be used"
);
}
/// Return a pointer to default immutable message with static lifetime.
///
/// ```
/// # use protobuf::Message;
/// # fn foo<MyMessage: Message>() {
/// let m: &MyMessage = MyMessage::default_instance();
/// # }
/// ```
fn default_instance() -> &'static Self
where
Self: Sized;
}
pub fn message_down_cast<'a, M: Message + 'a>(m: &'a dyn Message) -> &'a M {
m.as_any().downcast_ref::<M>().unwrap()
}
/// Parse message from reader.
/// Parse stops on EOF or when error encountered.
#[deprecated(since = "2.19", note = "Use Message::parse_from_reader instead")]
pub fn parse_from_reader<M: Message>(reader: &mut dyn Read) -> ProtobufResult<M> {
M::parse_from_reader(reader)
}
/// Parse message from byte array.
#[deprecated(since = "2.19", note = "Use Message::parse_from_bytes instead")]
pub fn parse_from_bytes<M: Message>(bytes: &[u8]) -> ProtobufResult<M> {
M::parse_from_bytes(bytes)
}
/// Parse message from `Bytes` object.
/// Resulting message may share references to the passed bytes object.
#[cfg(feature = "bytes")]
#[deprecated(
since = "2.19",
note = "Use Message::parse_from_carllerche_bytes instead"
)]
pub fn parse_from_carllerche_bytes<M: Message>(bytes: &Bytes) -> ProtobufResult<M> {
M::parse_from_carllerche_bytes(bytes)
}
/// Parse length-delimited message from stream.
///
/// Read varint length first, and read messages of that length then.
///
/// This function is deprecated and will be removed in the next major release.
#[deprecated]
pub fn parse_length_delimited_from<M: Message>(is: &mut CodedInputStream) -> ProtobufResult<M> {
is.read_message::<M>()
}
/// Parse length-delimited message from `Read`.
///
/// This function is deprecated and will be removed in the next major release.
#[deprecated]
pub fn parse_length_delimited_from_reader<M: Message>(r: &mut dyn Read) -> ProtobufResult<M> {
// TODO: wrong: we may read length first, and then read exact number of bytes needed
r.with_coded_input_stream(|is| is.read_message::<M>())
}
/// Parse length-delimited message from bytes.
///
/// This function is deprecated and will be removed in the next major release.
#[deprecated]
pub fn parse_length_delimited_from_bytes<M: Message>(bytes: &[u8]) -> ProtobufResult<M> {
bytes.with_coded_input_stream(|is| is.read_message::<M>())
}