gstreamer-rs/gstreamer/src/buffer_serde.rs
François Laignel 68263ffc7d Buffer: serde: add a TODO for a future better design attempt
Serialization and deserialization are asymetrical: ser uses string literals
and de uses a dedicated `struct`, leading to possible inconsistencies.

The idea is to rely on a single `struct` for both ser and de. The only
problem is that, in order to avoid unneeded copies, `buffer` requires an owned
`ByteBuf` for de and a borrowed `Bytes` for ser. `Either` could help adapting
to both situations.
2018-07-30 23:18:30 +03:00

269 lines
9.6 KiB
Rust

// Copyright (C) 2018 François Laignel <fengalin@free.fr>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use serde::de::{Deserialize, Deserializer};
use serde::ser;
use serde::ser::{Serialize, SerializeStruct, Serializer};
use serde_bytes::{ByteBuf, Bytes};
use Buffer;
use BufferFlags;
use BufferRef;
use ClockTime;
// TODO: try `Either<ByteBuf, Bytes>` to merge the base reprensentations for ser and de
// while avoiding unneeded copy
impl<'a> Serialize for BufferRef {
fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
let mut buffer = serializer.serialize_struct("Buffer", 6)?;
buffer.serialize_field("pts", &self.get_pts())?;
buffer.serialize_field("dts", &self.get_dts())?;
buffer.serialize_field("duration", &self.get_duration())?;
buffer.serialize_field("offset", &self.get_offset())?;
buffer.serialize_field("offset_end", &self.get_offset_end())?;
buffer.serialize_field("flags", &self.get_flags())?;
{
let data = self
.map_readable()
.ok_or_else(|| ser::Error::custom("Couldn't map `buffer` as readable"))?;
buffer.serialize_field("buffer", &Bytes::new(data.as_slice()))?;
}
buffer.end()
}
}
impl<'a> Serialize for Buffer {
fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
self.as_ref().serialize(serializer)
}
}
#[derive(Deserialize)]
struct BufferDe {
pts: ClockTime,
dts: ClockTime,
duration: ClockTime,
offset: u64,
offset_end: u64,
flags: BufferFlags,
buffer: ByteBuf,
}
impl From<BufferDe> for Buffer {
fn from(buf_de: BufferDe) -> Self {
let mut buffer = Buffer::from_mut_slice(buf_de.buffer.to_vec()).unwrap();
{
let buffer = buffer.get_mut().unwrap();
buffer.set_pts(buf_de.pts);
buffer.set_dts(buf_de.dts);
buffer.set_duration(buf_de.duration);
buffer.set_offset(buf_de.offset);
buffer.set_offset_end(buf_de.offset_end);
buffer.set_flags(buf_de.flags);
}
buffer
}
}
impl<'de> Deserialize<'de> for Buffer {
fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
BufferDe::deserialize(deserializer).map(|buffer_de| buffer_de.into())
}
}
#[cfg(test)]
mod tests {
extern crate ron;
extern crate serde_json;
extern crate serde_pickle;
use Buffer;
use BufferFlags;
#[test]
fn test_serialize() {
::init().unwrap();
let mut buffer = Buffer::from_slice(vec![1, 2, 3, 4]).unwrap();
{
let buffer = buffer.get_mut().unwrap();
buffer.set_pts(1.into());
buffer.set_offset(3);
buffer.set_offset_end(4);
buffer.set_duration(5.into());
buffer.set_flags(BufferFlags::LIVE | BufferFlags::LAST);
}
let mut pretty_config = ron::ser::PrettyConfig::default();
pretty_config.new_line = "".to_string();
let res = ron::ser::to_string_pretty(&buffer, pretty_config);
assert_eq!(
Ok(concat!(
"(",
" pts: Some(1),",
" dts: None,",
" duration: Some(5),",
" offset: 3,",
" offset_end: 4,",
" flags: (",
" bits: 1048592,",
" ),",
" buffer: \"AQIDBA==\",",
")"
).to_owned()),
res
);
let res = serde_json::to_string(&buffer).unwrap();
assert_eq!(
concat!(
"{",
"\"pts\":1,",
"\"dts\":null,",
"\"duration\":5,",
"\"offset\":3,",
"\"offset_end\":4,",
"\"flags\":{\"bits\":1048592},",
"\"buffer\":[1,2,3,4]",
"}"
).to_owned(),
res
);
let res = serde_pickle::to_vec(&buffer, true).unwrap();
assert_eq!(
vec![
128, 3, 125, 40, 88, 3, 0, 0, 0, 112, 116, 115, 74, 1, 0, 0, 0, 88, 3, 0, 0, 0,
100, 116, 115, 78, 88, 8, 0, 0, 0, 100, 117, 114, 97, 116, 105, 111, 110, 74, 5, 0,
0, 0, 88, 6, 0, 0, 0, 111, 102, 102, 115, 101, 116, 74, 3, 0, 0, 0, 88, 10, 0, 0,
0, 111, 102, 102, 115, 101, 116, 95, 101, 110, 100, 74, 4, 0, 0, 0, 88, 5, 0, 0, 0,
102, 108, 97, 103, 115, 125, 40, 88, 4, 0, 0, 0, 98, 105, 116, 115, 74, 16, 0, 16,
0, 117, 88, 6, 0, 0, 0, 98, 117, 102, 102, 101, 114, 67, 4, 1, 2, 3, 4, 117, 46,
],
res
);
}
#[test]
fn test_deserialize() {
::init().unwrap();
let buffer_ron = r#"
(
pts: Some(1),
dts: None,
duration: Some(5),
offset: 3,
offset_end: 4,
flags: (
bits: 1048592,
),
buffer: "AQIDBA==",
)
"#;
let buffer: Buffer = ron::de::from_str(buffer_ron).unwrap();
assert_eq!(buffer.get_pts(), 1.into());
assert_eq!(buffer.get_dts(), None.into());
assert_eq!(buffer.get_offset(), 3);
assert_eq!(buffer.get_offset_end(), 4);
assert_eq!(buffer.get_duration(), 5.into());
assert_eq!(buffer.get_flags(), BufferFlags::LIVE | BufferFlags::LAST);
{
let data = buffer.map_readable().unwrap();
assert_eq!(data.as_slice(), vec![1, 2, 3, 4].as_slice());
}
let buffer_json = r#"
{
"pts":1,
"dts":null,
"duration":5,
"offset":3,
"offset_end":4,
"flags":{"bits":1048592},
"buffer":[1,2,3,4]
}
"#;
let buffer: Buffer = serde_json::from_str(buffer_json).unwrap();
assert_eq!(buffer.get_pts(), 1.into());
assert_eq!(buffer.get_dts(), None.into());
assert_eq!(buffer.get_offset(), 3);
assert_eq!(buffer.get_offset_end(), 4);
assert_eq!(buffer.get_duration(), 5.into());
assert_eq!(buffer.get_flags(), BufferFlags::LIVE | BufferFlags::LAST);
{
let data = buffer.map_readable().unwrap();
assert_eq!(data.as_slice(), vec![1, 2, 3, 4].as_slice());
}
let buffer_pickle: &[u8] = &[
128, 3, 125, 40, 88, 3, 0, 0, 0, 112, 116, 115, 74, 1, 0, 0, 0, 88, 3, 0, 0, 0, 100,
116, 115, 78, 88, 8, 0, 0, 0, 100, 117, 114, 97, 116, 105, 111, 110, 74, 5, 0, 0, 0,
88, 6, 0, 0, 0, 111, 102, 102, 115, 101, 116, 74, 3, 0, 0, 0, 88, 10, 0, 0, 0, 111,
102, 102, 115, 101, 116, 95, 101, 110, 100, 74, 4, 0, 0, 0, 88, 5, 0, 0, 0, 102, 108,
97, 103, 115, 125, 40, 88, 4, 0, 0, 0, 98, 105, 116, 115, 74, 16, 0, 16, 0, 117, 88, 6,
0, 0, 0, 98, 117, 102, 102, 101, 114, 67, 4, 1, 2, 3, 4, 117, 46,
];
let buffer: Buffer = serde_pickle::from_slice(buffer_pickle).unwrap();
assert_eq!(buffer.get_pts(), 1.into());
assert_eq!(buffer.get_dts(), None.into());
assert_eq!(buffer.get_offset(), 3);
assert_eq!(buffer.get_offset_end(), 4);
assert_eq!(buffer.get_duration(), 5.into());
assert_eq!(buffer.get_flags(), BufferFlags::LIVE | BufferFlags::LAST);
{
let data = buffer.map_readable().unwrap();
assert_eq!(data.as_slice(), vec![1, 2, 3, 4].as_slice());
}
}
#[test]
fn test_serde_roundtrip() {
::init().unwrap();
let mut buffer = Buffer::from_slice(vec![1, 2, 3, 4]).unwrap();
{
let buffer = buffer.get_mut().unwrap();
buffer.set_pts(1.into());
buffer.set_offset(3);
buffer.set_offset_end(4);
buffer.set_duration(5.into());
buffer.set_flags(BufferFlags::LIVE | BufferFlags::LAST);
}
// Ron
let buffer_ser = ron::ser::to_string(&buffer).unwrap();
let buffer_de: Buffer = ron::de::from_str(buffer_ser.as_str()).unwrap();
assert_eq!(buffer_de.get_pts(), buffer.get_pts());
assert_eq!(buffer_de.get_dts(), buffer.get_dts());
assert_eq!(buffer_de.get_offset(), buffer.get_offset());
assert_eq!(buffer_de.get_offset_end(), buffer.get_offset_end());
assert_eq!(buffer_de.get_duration(), buffer.get_duration());
assert_eq!(buffer_de.get_flags(), buffer.get_flags());
{
let data = buffer_de.map_readable().unwrap();
assert_eq!(data.as_slice(), vec![1, 2, 3, 4].as_slice());
}
// Pickle
let buffer_ser = serde_pickle::to_vec(&buffer, true).unwrap();
let buffer_de: Buffer = serde_pickle::from_slice(buffer_ser.as_slice()).unwrap();
assert_eq!(buffer_de.get_pts(), buffer.get_pts());
assert_eq!(buffer_de.get_dts(), buffer.get_dts());
assert_eq!(buffer_de.get_offset(), buffer.get_offset());
assert_eq!(buffer_de.get_offset_end(), buffer.get_offset_end());
assert_eq!(buffer_de.get_duration(), buffer.get_duration());
assert_eq!(buffer_de.get_flags(), buffer.get_flags());
{
let data = buffer_de.map_readable().unwrap();
assert_eq!(data.as_slice(), vec![1, 2, 3, 4].as_slice());
}
}
}