qcow: Add qcow support

Extracted from crosvm (commit:f82d632), with clippy fixes.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
This commit is contained in:
Chao Peng 2019-04-29 19:32:56 +00:00 committed by Samuel Ortiz
parent c2c51dc9d1
commit 80ac3a84bb
7 changed files with 3000 additions and 0 deletions

58
Cargo.lock generated
View File

@ -141,6 +141,33 @@ dependencies = [
"vmm-sys-util 0.1.0 (git+https://github.com/sameo/vmm-sys-util)",
]
[[package]]
name = "proc-macro2"
version = "0.4.29"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "qcow"
version = "0.1.0"
dependencies = [
"byteorder 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
"libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
"log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
"remain 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
"vmm-sys-util 0.1.0 (git+https://github.com/sameo/vmm-sys-util)",
]
[[package]]
name = "quote"
version = "0.6.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"proc-macro2 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "redox_syscall"
version = "0.1.51"
@ -154,11 +181,31 @@ dependencies = [
"redox_syscall 0.1.51 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "remain"
version = "0.1.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"proc-macro2 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
"quote 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
"syn 0.15.33 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "strsim"
version = "0.6.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "syn"
version = "0.15.33"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"proc-macro2 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
"quote 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
"unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "termion"
version = "1.5.1"
@ -182,6 +229,11 @@ name = "unicode-width"
version = "0.1.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "unicode-xid"
version = "0.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "vec_map"
version = "0.8.1"
@ -215,6 +267,7 @@ dependencies = [
"libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
"linux-loader 0.1.0 (git+https://github.com/sameo/linux-loader)",
"pci 0.1.0",
"qcow 0.1.0",
"vm-memory 0.1.0 (git+https://github.com/rust-vmm/vm-memory)",
"vmm-sys-util 0.1.0 (git+https://github.com/sameo/vmm-sys-util)",
]
@ -260,12 +313,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
"checksum libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)" = "e962c7641008ac010fa60a7dfdc1712449f29c44ef2d4702394aea943ee75047"
"checksum linux-loader 0.1.0 (git+https://github.com/sameo/linux-loader)" = "<none>"
"checksum log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
"checksum proc-macro2 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)" = "64c827cea7a7ab30ce4593e5e04d7a11617ad6ece2fa230605a78b00ff965316"
"checksum quote 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "faf4799c5d274f3868a4aae320a0a182cbd2baee377b378f080e16a23e9d80db"
"checksum redox_syscall 0.1.51 (registry+https://github.com/rust-lang/crates.io-index)" = "423e376fffca3dfa06c9e9790a9ccd282fafb3cc6e6397d01dbf64f9bacc6b85"
"checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
"checksum remain 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3bec2543b50be4539fdc27fde082e218cf4c3895358ca77f5c52fe930589e209"
"checksum strsim 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b4d15c810519a91cf877e7e36e63fe068815c678181439f2f29e2562147c3694"
"checksum syn 0.15.33 (registry+https://github.com/rust-lang/crates.io-index)" = "ec52cd796e5f01d0067225a5392e70084acc4c0013fa71d55166d38a8b307836"
"checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
"checksum textwrap 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0b59b6b4b44d867f1370ef1bd91bfb262bf07bf0ae65c202ea2fbc16153b693"
"checksum unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "882386231c45df4700b275c7ff55b6f3698780a650026380e72dabe76fa46526"
"checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
"checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
"checksum vm-memory 0.1.0 (git+https://github.com/rust-vmm/vm-memory)" = "<none>"
"checksum vmm-sys-util 0.1.0 (git+https://github.com/sameo/vmm-sys-util)" = "<none>"

16
qcow/Cargo.toml Executable file
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@ -0,0 +1,16 @@
[package]
name = "qcow"
version = "0.1.0"
authors = ["The Chromium OS Authors"]
edition = "2018"
license = "BSD-3-Clause"
[lib]
path = "src/qcow.rs"
[dependencies]
byteorder = "*"
libc = "*"
log = "*"
remain = "*"
vmm-sys-util = { git = "https://github.com/sameo/vmm-sys-util" }

2351
qcow/src/qcow.rs Executable file

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qcow/src/qcow_raw_file.rs Normal file
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@ -0,0 +1,136 @@
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
use std::fs::File;
use std::io::{self, BufWriter, Seek, SeekFrom};
use std::mem::size_of;
use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
/// A qcow file. Allows reading/writing clusters and appending clusters.
#[derive(Debug)]
pub struct QcowRawFile {
file: File,
cluster_size: u64,
cluster_mask: u64,
}
impl QcowRawFile {
/// Creates a `QcowRawFile` from the given `File`, `None` is returned if `cluster_size` is not
/// a power of two.
pub fn from(file: File, cluster_size: u64) -> Option<Self> {
if cluster_size.count_ones() != 1 {
return None;
}
Some(QcowRawFile {
file,
cluster_size,
cluster_mask: cluster_size - 1,
})
}
/// Reads `count` 64 bit offsets and returns them as a vector.
/// `mask` optionally ands out some of the bits on the file.
pub fn read_pointer_table(
&mut self,
offset: u64,
count: u64,
mask: Option<u64>,
) -> io::Result<Vec<u64>> {
let mut table = vec![0; count as usize];
self.file.seek(SeekFrom::Start(offset))?;
self.file.read_u64_into::<BigEndian>(&mut table)?;
if let Some(m) = mask {
for ptr in &mut table {
*ptr &= m;
}
}
Ok(table)
}
/// Reads a cluster's worth of 64 bit offsets and returns them as a vector.
/// `mask` optionally ands out some of the bits on the file.
pub fn read_pointer_cluster(&mut self, offset: u64, mask: Option<u64>) -> io::Result<Vec<u64>> {
let count = self.cluster_size / size_of::<u64>() as u64;
self.read_pointer_table(offset, count, mask)
}
/// Writes `table` of u64 pointers to `offset` in the file.
/// `non_zero_flags` will be ORed with all non-zero values in `table`.
/// writing.
pub fn write_pointer_table(
&mut self,
offset: u64,
table: &[u64],
non_zero_flags: u64,
) -> io::Result<()> {
self.file.seek(SeekFrom::Start(offset))?;
let mut buffer = BufWriter::with_capacity(table.len() * size_of::<u64>(), &self.file);
for addr in table {
let val = if *addr == 0 {
0
} else {
*addr | non_zero_flags
};
buffer.write_u64::<BigEndian>(val)?;
}
Ok(())
}
/// Read a refcount block from the file and returns a Vec containing the block.
/// Always returns a cluster's worth of data.
pub fn read_refcount_block(&mut self, offset: u64) -> io::Result<Vec<u16>> {
let count = self.cluster_size / size_of::<u16>() as u64;
let mut table = vec![0; count as usize];
self.file.seek(SeekFrom::Start(offset))?;
self.file.read_u16_into::<BigEndian>(&mut table)?;
Ok(table)
}
/// Writes a refcount block to the file.
pub fn write_refcount_block(&mut self, offset: u64, table: &[u16]) -> io::Result<()> {
self.file.seek(SeekFrom::Start(offset))?;
let mut buffer = BufWriter::with_capacity(table.len() * size_of::<u16>(), &self.file);
for count in table {
buffer.write_u16::<BigEndian>(*count)?;
}
Ok(())
}
/// Allocates a new cluster at the end of the current file, return the address.
pub fn add_cluster_end(&mut self, max_valid_cluster_offset: u64) -> io::Result<Option<u64>> {
// Determine where the new end of the file should be and set_len, which
// translates to truncate(2).
let file_end: u64 = self.file.seek(SeekFrom::End(0))?;
let new_cluster_address: u64 = (file_end + self.cluster_size - 1) & !self.cluster_mask;
if new_cluster_address > max_valid_cluster_offset {
return Ok(None);
}
self.file.set_len(new_cluster_address + self.cluster_size)?;
Ok(Some(new_cluster_address))
}
/// Returns a reference to the underlying file.
pub fn file(&self) -> &File {
&self.file
}
/// Returns a mutable reference to the underlying file.
pub fn file_mut(&mut self) -> &mut File {
&mut self.file
}
/// Returns the size of the file's clusters.
pub fn cluster_size(&self) -> u64 {
self.cluster_size
}
/// Returns the offset of `address` within a cluster.
pub fn cluster_offset(&self, address: u64) -> u64 {
address & self.cluster_mask
}
}

253
qcow/src/refcount.rs Normal file
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@ -0,0 +1,253 @@
// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
use std;
use std::fmt::{self, Display};
use std::io;
use libc::EINVAL;
use crate::qcow_raw_file::QcowRawFile;
use crate::vec_cache::{CacheMap, Cacheable, VecCache};
#[derive(Debug)]
pub enum Error {
/// `EvictingCache` - Error writing a refblock from the cache to disk.
EvictingRefCounts(io::Error),
/// `InvalidIndex` - Address requested isn't within the range of the disk.
InvalidIndex,
/// `NeedCluster` - Handle this error by reading the cluster and calling the function again.
NeedCluster(u64),
/// `NeedNewCluster` - Handle this error by allocating a cluster and calling the function again.
NeedNewCluster,
/// `ReadingRefCounts` - Error reading the file in to the refcount cache.
ReadingRefCounts(io::Error),
}
pub type Result<T> = std::result::Result<T, Error>;
impl Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use self::Error::*;
match self {
EvictingRefCounts(e) => write!(
f,
"failed to write a refblock from the cache to disk: {}",
e
),
InvalidIndex => write!(f, "address requested is not within the range of the disk"),
NeedCluster(addr) => write!(f, "cluster with addr={} needs to be read", addr),
NeedNewCluster => write!(f, "new cluster needs to be allocated for refcounts"),
ReadingRefCounts(e) => {
write!(f, "failed to read the file into the refcount cache: {}", e)
}
}
}
}
/// Represents the refcount entries for an open qcow file.
#[derive(Debug)]
pub struct RefCount {
ref_table: VecCache<u64>,
refcount_table_offset: u64,
refblock_cache: CacheMap<VecCache<u16>>,
refcount_block_entries: u64, // number of refcounts in a cluster.
cluster_size: u64,
max_valid_cluster_offset: u64,
}
impl RefCount {
/// Creates a `RefCount` from `file`, reading the refcount table from `refcount_table_offset`.
/// `refcount_table_entries` specifies the number of refcount blocks used by this image.
/// `refcount_block_entries` indicates the number of refcounts in each refcount block.
/// Each refcount table entry points to a refcount block.
pub fn new(
raw_file: &mut QcowRawFile,
refcount_table_offset: u64,
refcount_table_entries: u64,
refcount_block_entries: u64,
cluster_size: u64,
) -> io::Result<RefCount> {
let ref_table = VecCache::from_vec(raw_file.read_pointer_table(
refcount_table_offset,
refcount_table_entries,
None,
)?);
let max_valid_cluster_index = (ref_table.len() as u64) * refcount_block_entries - 1;
let max_valid_cluster_offset = max_valid_cluster_index * cluster_size;
Ok(RefCount {
ref_table,
refcount_table_offset,
refblock_cache: CacheMap::new(50),
refcount_block_entries,
cluster_size,
max_valid_cluster_offset,
})
}
/// Returns the number of refcounts per block.
pub fn refcounts_per_block(&self) -> u64 {
self.refcount_block_entries
}
/// Returns the maximum valid cluster offset in the raw file for this refcount table.
pub fn max_valid_cluster_offset(&self) -> u64 {
self.max_valid_cluster_offset
}
/// Returns `NeedNewCluster` if a new cluster needs to be allocated for refcounts. If an
/// existing cluster needs to be read, `NeedCluster(addr)` is returned. The Caller should
/// allocate a cluster or read the required one and call this function again with the cluster.
/// On success, an optional address of a dropped cluster is returned. The dropped cluster can
/// be reused for other purposes.
pub fn set_cluster_refcount(
&mut self,
raw_file: &mut QcowRawFile,
cluster_address: u64,
refcount: u16,
mut new_cluster: Option<(u64, VecCache<u16>)>,
) -> Result<Option<u64>> {
let (table_index, block_index) = self.get_refcount_index(cluster_address);
let block_addr_disk = *self.ref_table.get(table_index).ok_or(Error::InvalidIndex)?;
// Fill the cache if this block isn't yet there.
if !self.refblock_cache.contains_key(table_index) {
// Need a new cluster
if let Some((addr, table)) = new_cluster.take() {
self.ref_table[table_index] = addr;
let ref_table = &self.ref_table;
self.refblock_cache
.insert(table_index, table, |index, evicted| {
raw_file.write_refcount_block(ref_table[index], evicted.get_values())
})
.map_err(Error::EvictingRefCounts)?;
} else {
if block_addr_disk == 0 {
return Err(Error::NeedNewCluster);
}
return Err(Error::NeedCluster(block_addr_disk));
}
}
// Unwrap is safe here as the entry was filled directly above.
let dropped_cluster = if !self.refblock_cache.get(table_index).unwrap().dirty() {
// Free the previously used block and use a new one. Writing modified counts to new
// blocks keeps the on-disk state consistent even if it's out of date.
if let Some((addr, _)) = new_cluster.take() {
self.ref_table[table_index] = addr;
Some(block_addr_disk)
} else {
return Err(Error::NeedNewCluster);
}
} else {
None
};
self.refblock_cache.get_mut(table_index).unwrap()[block_index] = refcount;
Ok(dropped_cluster)
}
/// Flush the dirty refcount blocks. This must be done before flushing the table that points to
/// the blocks.
pub fn flush_blocks(&mut self, raw_file: &mut QcowRawFile) -> io::Result<()> {
// Write out all dirty L2 tables.
for (table_index, block) in self.refblock_cache.iter_mut().filter(|(_k, v)| v.dirty()) {
let addr = self.ref_table[*table_index];
if addr != 0 {
raw_file.write_refcount_block(addr, block.get_values())?;
} else {
return Err(std::io::Error::from_raw_os_error(EINVAL));
}
block.mark_clean();
}
Ok(())
}
/// Flush the refcount table that keeps the address of the refcounts blocks.
/// Returns true if the table changed since the previous `flush_table()` call.
pub fn flush_table(&mut self, raw_file: &mut QcowRawFile) -> io::Result<bool> {
if self.ref_table.dirty() {
raw_file.write_pointer_table(
self.refcount_table_offset,
&self.ref_table.get_values(),
0,
)?;
self.ref_table.mark_clean();
Ok(true)
} else {
Ok(false)
}
}
/// Gets the refcount for a cluster with the given address.
pub fn get_cluster_refcount(
&mut self,
raw_file: &mut QcowRawFile,
address: u64,
) -> Result<u16> {
let (table_index, block_index) = self.get_refcount_index(address);
let block_addr_disk = *self.ref_table.get(table_index).ok_or(Error::InvalidIndex)?;
if block_addr_disk == 0 {
return Ok(0);
}
if !self.refblock_cache.contains_key(table_index) {
let table = VecCache::from_vec(
raw_file
.read_refcount_block(block_addr_disk)
.map_err(Error::ReadingRefCounts)?,
);
let ref_table = &self.ref_table;
self.refblock_cache
.insert(table_index, table, |index, evicted| {
raw_file.write_refcount_block(ref_table[index], evicted.get_values())
})
.map_err(Error::EvictingRefCounts)?;
}
Ok(self.refblock_cache.get(table_index).unwrap()[block_index])
}
/// Returns the refcount table for this file. This is only useful for debugging.
pub fn ref_table(&self) -> &[u64] {
&self.ref_table.get_values()
}
/// Returns the refcounts stored in the given block.
pub fn refcount_block(
&mut self,
raw_file: &mut QcowRawFile,
table_index: usize,
) -> Result<Option<&[u16]>> {
let block_addr_disk = *self.ref_table.get(table_index).ok_or(Error::InvalidIndex)?;
if block_addr_disk == 0 {
return Ok(None);
}
if !self.refblock_cache.contains_key(table_index) {
let table = VecCache::from_vec(
raw_file
.read_refcount_block(block_addr_disk)
.map_err(Error::ReadingRefCounts)?,
);
// TODO(dgreid) - closure needs to return an error.
let ref_table = &self.ref_table;
self.refblock_cache
.insert(table_index, table, |index, evicted| {
raw_file.write_refcount_block(ref_table[index], evicted.get_values())
})
.map_err(Error::EvictingRefCounts)?;
}
// The index must exist as it was just inserted if it didn't already.
Ok(Some(
self.refblock_cache.get(table_index).unwrap().get_values(),
))
}
// Gets the address of the refcount block and the index into the block for the given address.
fn get_refcount_index(&self, address: u64) -> (usize, usize) {
let block_index = (address / self.cluster_size) % self.refcount_block_entries;
let refcount_table_index = (address / self.cluster_size) / self.refcount_block_entries;
(refcount_table_index as usize, block_index as usize)
}
}

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qcow/src/vec_cache.rs Normal file
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// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
use std::collections::hash_map::IterMut;
use std::collections::HashMap;
use std::io;
use std::ops::{Index, IndexMut};
use std::slice::SliceIndex;
/// Trait that allows for checking if an implementor is dirty. Useful for types that are cached so
/// it can be checked if they need to be committed to disk.
pub trait Cacheable {
/// Used to check if the item needs to be written out or if it can be discarded.
fn dirty(&self) -> bool;
}
#[derive(Debug)]
/// Represents a vector that implements the `Cacheable` trait so it can be held in a cache.
pub struct VecCache<T: 'static + Copy + Default> {
vec: Box<[T]>,
dirty: bool,
}
impl<T: 'static + Copy + Default> VecCache<T> {
/// Creates a `VecCache` that can hold `count` elements.
pub fn new(count: usize) -> VecCache<T> {
VecCache {
vec: vec![Default::default(); count].into_boxed_slice(),
dirty: true,
}
}
/// Creates a `VecCache` from the passed in `vec`.
pub fn from_vec(vec: Vec<T>) -> VecCache<T> {
VecCache {
vec: vec.into_boxed_slice(),
dirty: false,
}
}
pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output>
where
I: SliceIndex<[T]>,
{
self.vec.get(index)
}
/// Gets a reference to the underlying vector.
pub fn get_values(&self) -> &[T] {
&self.vec
}
/// Mark this cache element as clean.
pub fn mark_clean(&mut self) {
self.dirty = false;
}
/// Returns the number of elements in the vector.
pub fn len(&self) -> usize {
self.vec.len()
}
}
impl<T: 'static + Copy + Default> Cacheable for VecCache<T> {
fn dirty(&self) -> bool {
self.dirty
}
}
impl<T: 'static + Copy + Default> Index<usize> for VecCache<T> {
type Output = T;
fn index(&self, index: usize) -> &T {
self.vec.index(index)
}
}
impl<T: 'static + Copy + Default> IndexMut<usize> for VecCache<T> {
fn index_mut(&mut self, index: usize) -> &mut T {
self.dirty = true;
self.vec.index_mut(index)
}
}
#[derive(Debug)]
pub struct CacheMap<T: Cacheable> {
capacity: usize,
map: HashMap<usize, T>,
}
impl<T: Cacheable> CacheMap<T> {
pub fn new(capacity: usize) -> Self {
CacheMap {
capacity,
map: HashMap::with_capacity(capacity),
}
}
pub fn contains_key(&self, key: usize) -> bool {
self.map.contains_key(&key)
}
pub fn get(&self, index: usize) -> Option<&T> {
self.map.get(&index)
}
pub fn get_mut(&mut self, index: usize) -> Option<&mut T> {
self.map.get_mut(&index)
}
pub fn iter_mut(&mut self) -> IterMut<usize, T> {
self.map.iter_mut()
}
// Check if the refblock cache is full and we need to evict.
pub fn insert<F>(&mut self, index: usize, block: T, write_callback: F) -> io::Result<()>
where
F: FnOnce(usize, T) -> io::Result<()>,
{
if self.map.len() == self.capacity {
// TODO(dgreid) - smarter eviction strategy.
let to_evict = *self.map.iter().nth(0).unwrap().0;
if let Some(evicted) = self.map.remove(&to_evict) {
if evicted.dirty() {
write_callback(to_evict, evicted)?;
}
}
}
self.map.insert(index, block);
Ok(())
}
}
#[cfg(test)]
mod tests {
use super::*;
struct NumCache(pub u64);
impl Cacheable for NumCache {
fn dirty(&self) -> bool {
true
}
}
#[test]
fn evicts_when_full() {
let mut cache = CacheMap::<NumCache>::new(3);
let mut evicted = None;
cache
.insert(0, NumCache(5), |index, _| {
evicted = Some(index);
Ok(())
})
.unwrap();
assert_eq!(evicted, None);
cache
.insert(1, NumCache(6), |index, _| {
evicted = Some(index);
Ok(())
})
.unwrap();
assert_eq!(evicted, None);
cache
.insert(2, NumCache(7), |index, _| {
evicted = Some(index);
Ok(())
})
.unwrap();
assert_eq!(evicted, None);
cache
.insert(3, NumCache(8), |index, _| {
evicted = Some(index);
Ok(())
})
.unwrap();
assert!(evicted.is_some());
// Check that three of the four items inserted are still there and that the most recently
// inserted is one of them.
let num_items = (0..=3).filter(|k| cache.contains_key(&k)).count();
assert_eq!(num_items, 3);
assert!(cache.contains_key(&3));
}
}

1
vmm/Cargo.toml Normal file → Executable file
View File

@ -12,6 +12,7 @@ kvm-bindings = "0.1"
kvm-ioctls = { git = "https://github.com/rust-vmm/kvm-ioctls" }
libc = ">=0.2.39"
pci = {path = "../pci"}
qcow = { path = "../qcow" }
linux-loader = { git = "https://github.com/sameo/linux-loader" }
vmm-sys-util = { git = "https://github.com/sameo/vmm-sys-util" }