rutabaga_gfx/
rutabaga_snapshot.rs

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1// Copyright 2023 The ChromiumOS Authors
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use std::collections::BTreeMap;
6use std::io::Read;
7use std::io::Write;
8
9use zerocopy::AsBytes;
10use zerocopy::FromBytes;
11
12pub struct RutabagaSnapshot {
13    pub resources: BTreeMap<u32, RutabagaResourceSnapshot>,
14}
15
16pub struct RutabagaResourceSnapshot {
17    pub resource_id: u32,
18    pub width: u32,
19    pub height: u32,
20}
21
22impl RutabagaSnapshot {
23    // To avoid adding a build dependency, we use a custom serialization format. It is an internal
24    // detail, doesn't need to support host migration (e.g. we don't need to care about endianess
25    // or integer sizes), and isn't expected to be stable across releases.
26    pub fn serialize_to(&self, w: &mut impl Write) -> std::io::Result<()> {
27        fn write(w: &mut impl Write, v: impl AsBytes) -> std::io::Result<()> {
28            w.write_all(v.as_bytes())
29        }
30
31        write(w, self.resources.len())?;
32        for (id, resource) in self.resources.iter() {
33            assert_eq!(*id, resource.resource_id);
34            write(w, resource.resource_id)?;
35            write(w, resource.width)?;
36            write(w, resource.height)?;
37        }
38
39        Ok(())
40    }
41
42    pub fn deserialize_from(r: &mut impl Read) -> std::io::Result<Self> {
43        fn read<T: AsBytes + FromBytes + Default>(r: &mut impl Read) -> std::io::Result<T> {
44            let mut v: T = Default::default();
45            r.read_exact(v.as_bytes_mut())?;
46            Ok(v)
47        }
48
49        let num_resources: usize = read::<usize>(r)?;
50        let mut resources = BTreeMap::new();
51        for _ in 0..num_resources {
52            let resource_id = read(r)?;
53            let width = read(r)?;
54            let height = read(r)?;
55            resources.insert(
56                resource_id,
57                RutabagaResourceSnapshot {
58                    resource_id,
59                    width,
60                    height,
61                },
62            );
63        }
64
65        // Verify we have consumed the all the input by checking for EOF.
66        let mut buf = [0u8];
67        if r.read(&mut buf)? != 0 {
68            return Err(std::io::ErrorKind::InvalidData.into());
69        }
70
71        Ok(RutabagaSnapshot { resources })
72    }
73}
rutabaga_gfx/rutabaga_snapshot.rs

rutabaga_gfx/
rutabaga_snapshot.rs
