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use std::io::Read;
use std::io::Write;
use crate::coded_output_stream::with::WithCodedOutputStream;
use crate::error::ProtobufError;
use crate::wire_format::check_message_size;
use crate::CodedInputStream;
use crate::CodedOutputStream;
use crate::SpecialFields;
use crate::UnknownFields;
/// Trait which is implemented by all generated message.
///
/// Note, by default all generated messages also implement [`MessageFull`](crate::MessageFull)
/// trait which provides access to reflection and features which depend on reflection
/// (text format and JSON serialization).
pub trait Message: Default + Clone + Send + Sync + Sized + PartialEq + 'static {
/// Message name as specified in `.proto` file.
///
/// Message name can be accessed using
/// [`MessageFull::descriptor`](crate::MessageFull::descriptor),
/// but when lite runtime is requested, this field can be used.
const NAME: &'static str;
/// 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) -> crate::Result<()>;
/// Parse message from stream.
fn parse_from(is: &mut CodedInputStream) -> crate::Result<Self> {
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) -> crate::Result<()>;
/// Compute and cache size of this message and all nested messages.
///
/// Note if the computation overflows u32, the cached size is stored truncated.
fn compute_size(&self) -> u64;
/// Get size previously computed by `compute_size`.
///
/// Note if message size exceeds u32, the cached size is stored truncated.
fn cached_size(&self) -> u32 {
self.special_fields().cached_size().get()
}
/// Write the message to the stream.
///
/// Results in error if message is not fully initialized.
fn write_to(&self, os: &mut CodedOutputStream) -> crate::Result<()> {
self.check_initialized()?;
// cache sizes
let size = self.compute_size();
let size = check_message_size(size)?;
os.reserve_additional(size as u32, Self::NAME)?;
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) -> crate::Result<()> {
let size = self.compute_size();
let size = check_message_size(size)?;
os.reserve_additional_for_length_delimited(size, Self::NAME)?;
os.write_raw_varint32(size)?;
let written = os.total_bytes_written();
self.write_to_with_cached_sizes(os)?;
// Self-check.
assert_eq!(
written + size as u64,
os.total_bytes_written(),
"Expected to write {}, actually wrote {}",
size,
os.total_bytes_written() - written
);
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>) -> crate::Result<()> {
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]) -> crate::Result<()> {
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) -> crate::Result<Self> {
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]) -> crate::Result<Self> {
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_tokio_bytes(bytes: &bytes::Bytes) -> crate::Result<Self> {
let mut is = CodedInputStream::from_tokio_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) -> crate::Result<()> {
if !self.is_initialized() {
Err(ProtobufError::MessageNotInitialized(Self::NAME.to_owned()).into())
} else {
Ok(())
}
}
/// Write the message to the writer.
fn write_to_writer(&self, w: &mut dyn Write) -> crate::Result<()> {
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>) -> crate::Result<()> {
v.with_coded_output_stream(|os| self.write_to(os))
}
/// Write the message to bytes vec.
///
/// > **Note**: You can use [`Message::parse_from_bytes`]
/// to do the reverse.
fn write_to_bytes(&self) -> crate::Result<Vec<u8>> {
self.check_initialized()?;
let size = self.compute_size() as usize;
let mut v = Vec::with_capacity(size);
let mut os = CodedOutputStream::vec(&mut v);
self.write_to_with_cached_sizes(&mut os)?;
os.flush()?;
drop(os);
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) -> crate::Result<()> {
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) -> crate::Result<Vec<u8>> {
let mut v = Vec::new();
v.with_coded_output_stream(|os| self.write_length_delimited_to(os))?;
Ok(v)
}
/// Special fields (unknown fields and cached size).
fn special_fields(&self) -> &SpecialFields;
/// Special fields (unknown fields and cached size).
fn mut_special_fields(&mut self) -> &mut SpecialFields;
/// Get a reference to unknown fields.
fn unknown_fields(&self) -> &UnknownFields {
&self.special_fields().unknown_fields()
}
/// Get a mutable reference to unknown fields.
fn mut_unknown_fields(&mut self) -> &mut UnknownFields {
self.mut_special_fields().mut_unknown_fields()
}
/// Create an empty message object.
///
/// ```
/// # use protobuf::MessageFull;
/// # fn foo<MyMessage: MessageFull>() {
/// let m = MyMessage::new();
/// # }
/// ```
fn new() -> Self;
/// Reset all fields.
fn clear(&mut self) {
*self = Self::new();
}
/// Return a pointer to default immutable message with static lifetime.
///
/// ```
/// # use protobuf::MessageFull;
/// # fn foo<MyMessage: MessageFull>() {
/// let m: &MyMessage = MyMessage::default_instance();
/// # }
/// ```
fn default_instance() -> &'static Self;
}