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third_party_rust_bytes/tests/test_bytes.rs
T
Carl Lerche f686ca6964 Add advance on Bytes and BytesMut (#166)
* Compact Bytes original capacity representation

In order to avoid unnecessary allocations, a `Bytes` structure remembers
the capacity with which it was first created. When a reserve operation
is issued, this original capacity value is used to as a baseline for
reallocating new storage.

Previously, this original capacity value was stored in its raw form. In
other words, the original capacity `usize` was stored as is. In order to
reclaim some `Bytes` internal storage space for additional features,
this original capacity value is compressed from requiring 16 bits to 3.

To do this, instead of storing the exact original capacity. The original
capacity is rounded down to the nearest power of two. If the original
capacity is less than 1024, then it is rounded down to zero. This
roughly means that the original capacity is now stored as a table:

0 => 0
1 => 1k
2 => 2k
3 => 4k
4 => 8k
5 => 16k
6 => 32k
7 => 64k

For the purposes that the original capacity feature was introduced, this
is sufficient granularity.

* Provide `advance` on Bytes and BytesMut

This is the `advance` function that would be part of a `Buf`
implementation. However, `Bytes` and `BytesMut` cannot impl `Buf` until
the next breaking release.

The implementation uses the additional storage made available by the
previous commit to store the number of bytes that the view was advanced.
The `ptr` pointer will point to the start of the window, avoiding any
pointer arithmetic when dereferencing the `Bytes` handle.
2017-12-13 13:30:03 -06:00

555 lines
12 KiB
Rust

extern crate bytes;
use bytes::{Bytes, BytesMut, BufMut};
const LONG: &'static [u8] = b"mary had a little lamb, little lamb, little lamb";
const SHORT: &'static [u8] = b"hello world";
fn inline_cap() -> usize {
use std::mem;
4 * mem::size_of::<usize>() - 1
}
fn is_sync<T: Sync>() {}
fn is_send<T: Send>() {}
#[test]
fn test_bounds() {
is_sync::<Bytes>();
is_sync::<BytesMut>();
is_send::<Bytes>();
is_send::<BytesMut>();
}
#[test]
fn from_slice() {
let a = Bytes::from(&b"abcdefgh"[..]);
assert_eq!(a, b"abcdefgh"[..]);
assert_eq!(a, &b"abcdefgh"[..]);
assert_eq!(a, Vec::from(&b"abcdefgh"[..]));
assert_eq!(b"abcdefgh"[..], a);
assert_eq!(&b"abcdefgh"[..], a);
assert_eq!(Vec::from(&b"abcdefgh"[..]), a);
let a = BytesMut::from(&b"abcdefgh"[..]);
assert_eq!(a, b"abcdefgh"[..]);
assert_eq!(a, &b"abcdefgh"[..]);
assert_eq!(a, Vec::from(&b"abcdefgh"[..]));
assert_eq!(b"abcdefgh"[..], a);
assert_eq!(&b"abcdefgh"[..], a);
assert_eq!(Vec::from(&b"abcdefgh"[..]), a);
}
#[test]
fn fmt() {
let a = format!("{:?}", Bytes::from(&b"abcdefg"[..]));
let b = "b\"abcdefg\"";
assert_eq!(a, b);
let a = format!("{:?}", BytesMut::from(&b"abcdefg"[..]));
assert_eq!(a, b);
}
#[test]
fn fmt_write() {
use std::fmt::Write;
use std::iter::FromIterator;
let s = String::from_iter((0..10).map(|_| "abcdefg"));
let mut a = BytesMut::with_capacity(64);
write!(a, "{}", &s[..64]).unwrap();
assert_eq!(a, s[..64].as_bytes());
let mut b = BytesMut::with_capacity(64);
write!(b, "{}", &s[..32]).unwrap();
write!(b, "{}", &s[32..64]).unwrap();
assert_eq!(b, s[..64].as_bytes());
let mut c = BytesMut::with_capacity(64);
write!(c, "{}", s).unwrap_err();
assert!(c.is_empty());
}
#[test]
fn len() {
let a = Bytes::from(&b"abcdefg"[..]);
assert_eq!(a.len(), 7);
let a = BytesMut::from(&b"abcdefg"[..]);
assert_eq!(a.len(), 7);
let a = Bytes::from(&b""[..]);
assert!(a.is_empty());
let a = BytesMut::from(&b""[..]);
assert!(a.is_empty());
}
#[test]
fn index() {
let a = Bytes::from(&b"hello world"[..]);
assert_eq!(a[0..5], *b"hello");
}
#[test]
fn slice() {
let a = Bytes::from(&b"hello world"[..]);
let b = a.slice(3, 5);
assert_eq!(b, b"lo"[..]);
let b = a.slice(0, 0);
assert_eq!(b, b""[..]);
let b = a.slice(3, 3);
assert_eq!(b, b""[..]);
let b = a.slice(a.len(), a.len());
assert_eq!(b, b""[..]);
let b = a.slice_to(5);
assert_eq!(b, b"hello"[..]);
let b = a.slice_from(3);
assert_eq!(b, b"lo world"[..]);
}
#[test]
#[should_panic]
fn slice_oob_1() {
let a = Bytes::from(&b"hello world"[..]);
a.slice(5, inline_cap() + 1);
}
#[test]
#[should_panic]
fn slice_oob_2() {
let a = Bytes::from(&b"hello world"[..]);
a.slice(inline_cap() + 1, inline_cap() + 5);
}
#[test]
fn split_off() {
let mut hello = Bytes::from(&b"helloworld"[..]);
let world = hello.split_off(5);
assert_eq!(hello, &b"hello"[..]);
assert_eq!(world, &b"world"[..]);
let mut hello = BytesMut::from(&b"helloworld"[..]);
let world = hello.split_off(5);
assert_eq!(hello, &b"hello"[..]);
assert_eq!(world, &b"world"[..]);
}
#[test]
#[should_panic]
fn split_off_oob() {
let mut hello = Bytes::from(&b"helloworld"[..]);
hello.split_off(inline_cap() + 1);
}
#[test]
fn split_off_uninitialized() {
let mut bytes = BytesMut::with_capacity(1024);
let other = bytes.split_off(128);
assert_eq!(bytes.len(), 0);
assert_eq!(bytes.capacity(), 128);
assert_eq!(other.len(), 0);
assert_eq!(other.capacity(), 896);
}
#[test]
fn split_off_to_loop() {
let s = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
for i in 0..(s.len() + 1) {
{
let mut bytes = Bytes::from(&s[..]);
let off = bytes.split_off(i);
assert_eq!(i, bytes.len());
let mut sum = Vec::new();
sum.extend(&bytes);
sum.extend(&off);
assert_eq!(&s[..], &sum[..]);
}
{
let mut bytes = BytesMut::from(&s[..]);
let off = bytes.split_off(i);
assert_eq!(i, bytes.len());
let mut sum = Vec::new();
sum.extend(&bytes);
sum.extend(&off);
assert_eq!(&s[..], &sum[..]);
}
{
let mut bytes = Bytes::from(&s[..]);
let off = bytes.split_to(i);
assert_eq!(i, off.len());
let mut sum = Vec::new();
sum.extend(&off);
sum.extend(&bytes);
assert_eq!(&s[..], &sum[..]);
}
{
let mut bytes = BytesMut::from(&s[..]);
let off = bytes.split_to(i);
assert_eq!(i, off.len());
let mut sum = Vec::new();
sum.extend(&off);
sum.extend(&bytes);
assert_eq!(&s[..], &sum[..]);
}
}
}
#[test]
fn split_to_1() {
// Inline
let mut a = Bytes::from(SHORT);
let b = a.split_to(4);
assert_eq!(SHORT[4..], a);
assert_eq!(SHORT[..4], b);
// Allocated
let mut a = Bytes::from(LONG);
let b = a.split_to(4);
assert_eq!(LONG[4..], a);
assert_eq!(LONG[..4], b);
let mut a = Bytes::from(LONG);
let b = a.split_to(30);
assert_eq!(LONG[30..], a);
assert_eq!(LONG[..30], b);
}
#[test]
fn split_to_2() {
let mut a = Bytes::from(LONG);
assert_eq!(LONG, a);
let b = a.split_to(1);
assert_eq!(LONG[1..], a);
drop(b);
}
#[test]
#[should_panic]
fn split_to_oob() {
let mut hello = Bytes::from(&b"helloworld"[..]);
hello.split_to(inline_cap() + 1);
}
#[test]
#[should_panic]
fn split_to_oob_mut() {
let mut hello = BytesMut::from(&b"helloworld"[..]);
hello.split_to(inline_cap() + 1);
}
#[test]
fn split_to_uninitialized() {
let mut bytes = BytesMut::with_capacity(1024);
let other = bytes.split_to(128);
assert_eq!(bytes.len(), 0);
assert_eq!(bytes.capacity(), 896);
assert_eq!(other.len(), 0);
assert_eq!(other.capacity(), 128);
}
#[test]
fn split_off_to_at_gt_len() {
fn make_bytes() -> Bytes {
let mut bytes = BytesMut::with_capacity(100);
bytes.put_slice(&[10, 20, 30, 40]);
bytes.freeze()
}
use std::panic;
make_bytes().split_to(4);
make_bytes().split_off(4);
assert!(panic::catch_unwind(move || {
make_bytes().split_to(5);
}).is_err());
assert!(panic::catch_unwind(move || {
make_bytes().split_off(5);
}).is_err());
}
#[test]
fn fns_defined_for_bytes_mut() {
let mut bytes = BytesMut::from(&b"hello world"[..]);
bytes.as_ptr();
bytes.as_mut_ptr();
// Iterator
let v: Vec<u8> = bytes.iter().map(|b| *b).collect();
assert_eq!(&v[..], bytes);
}
#[test]
fn reserve_convert() {
// Inline -> Vec
let mut bytes = BytesMut::with_capacity(8);
bytes.put("hello");
bytes.reserve(40);
assert_eq!(bytes.capacity(), 45);
assert_eq!(bytes, "hello");
// Inline -> Inline
let mut bytes = BytesMut::with_capacity(inline_cap());
bytes.put("abcdefghijkl");
let a = bytes.split_to(10);
bytes.reserve(inline_cap() - 3);
assert_eq!(inline_cap(), bytes.capacity());
assert_eq!(bytes, "kl");
assert_eq!(a, "abcdefghij");
// Vec -> Vec
let mut bytes = BytesMut::from(LONG);
bytes.reserve(64);
assert_eq!(bytes.capacity(), LONG.len() + 64);
// Arc -> Vec
let mut bytes = BytesMut::from(LONG);
let a = bytes.split_to(30);
bytes.reserve(128);
assert!(bytes.capacity() >= bytes.len() + 128);
drop(a);
}
#[test]
fn reserve_growth() {
let mut bytes = BytesMut::with_capacity(64);
bytes.put("hello world");
let _ = bytes.take();
bytes.reserve(65);
assert_eq!(bytes.capacity(), 128);
}
#[test]
fn reserve_allocates_at_least_original_capacity() {
let mut bytes = BytesMut::with_capacity(1024);
for i in 0..1020 {
bytes.put(i as u8);
}
let _other = bytes.take();
bytes.reserve(16);
assert_eq!(bytes.capacity(), 1024);
}
#[test]
fn reserve_max_original_capacity_value() {
const SIZE: usize = 128 * 1024;
let mut bytes = BytesMut::with_capacity(SIZE);
for _ in 0..SIZE {
bytes.put(0u8);
}
let _other = bytes.take();
bytes.reserve(16);
assert_eq!(bytes.capacity(), 64 * 1024);
}
#[test]
fn reserve_in_arc_unique_does_not_overallocate() {
let mut bytes = BytesMut::with_capacity(1000);
bytes.take();
// now bytes is Arc and refcount == 1
assert_eq!(1000, bytes.capacity());
bytes.reserve(2001);
assert_eq!(2001, bytes.capacity());
}
#[test]
fn reserve_in_arc_unique_doubles() {
let mut bytes = BytesMut::with_capacity(1000);
bytes.take();
// now bytes is Arc and refcount == 1
assert_eq!(1000, bytes.capacity());
bytes.reserve(1001);
assert_eq!(2000, bytes.capacity());
}
#[test]
fn reserve_in_arc_nonunique_does_not_overallocate() {
let mut bytes = BytesMut::with_capacity(1000);
let _copy = bytes.take();
// now bytes is Arc and refcount == 2
assert_eq!(1000, bytes.capacity());
bytes.reserve(2001);
assert_eq!(2001, bytes.capacity());
}
#[test]
fn inline_storage() {
let mut bytes = BytesMut::with_capacity(inline_cap());
let zero = [0u8; 64];
bytes.put(&zero[0..inline_cap()]);
assert_eq!(*bytes, zero[0..inline_cap()]);
}
#[test]
fn extend_mut() {
let mut bytes = BytesMut::with_capacity(0);
bytes.extend(LONG);
assert_eq!(*bytes, LONG[..]);
}
#[test]
fn extend_shr() {
let mut bytes = Bytes::new();
bytes.extend(LONG);
assert_eq!(*bytes, LONG[..]);
}
#[test]
fn extend_from_slice_mut() {
for &i in &[3, 34] {
let mut bytes = BytesMut::new();
bytes.extend_from_slice(&LONG[..i]);
bytes.extend_from_slice(&LONG[i..]);
assert_eq!(LONG[..], *bytes);
}
}
#[test]
fn extend_from_slice_shr() {
for &i in &[3, 34] {
let mut bytes = Bytes::new();
bytes.extend_from_slice(&LONG[..i]);
bytes.extend_from_slice(&LONG[i..]);
assert_eq!(LONG[..], *bytes);
}
}
#[test]
fn from_static() {
let mut a = Bytes::from_static(b"ab");
let b = a.split_off(1);
assert_eq!(a, b"a"[..]);
assert_eq!(b, b"b"[..]);
}
#[test]
fn advance_inline() {
let mut a = Bytes::from(&b"hello world"[..]);
a.advance(6);
assert_eq!(a, &b"world"[..]);
}
#[test]
fn advance_static() {
let mut a = Bytes::from_static(b"hello world");
a.advance(6);
assert_eq!(a, &b"world"[..]);
}
#[test]
fn advance_vec() {
let mut a = BytesMut::from(b"hello world boooo yah world zomg wat wat".to_vec());
a.advance(16);
assert_eq!(a, b"o yah world zomg wat wat"[..]);
a.advance(4);
assert_eq!(a, b"h world zomg wat wat"[..]);
// Reserve some space.
a.reserve(1024);
assert_eq!(a, b"h world zomg wat wat"[..]);
a.advance(6);
assert_eq!(a, b"d zomg wat wat"[..]);
}
#[test]
#[should_panic]
fn advance_past_len() {
let mut a = BytesMut::from(b"hello world".to_vec());
a.advance(20);
}
#[test]
// Only run these tests on little endian systems. CI uses qemu for testing
// little endian... and qemu doesn't really support threading all that well.
#[cfg(target_endian = "little")]
fn stress() {
// Tests promoting a buffer from a vec -> shared in a concurrent situation
use std::sync::{Arc, Barrier};
use std::thread;
const THREADS: usize = 8;
const ITERS: usize = 1_000;
for i in 0..ITERS {
let data = [i as u8; 256];
let buf = Arc::new(Bytes::from(&data[..]));
let barrier = Arc::new(Barrier::new(THREADS));
let mut joins = Vec::with_capacity(THREADS);
for _ in 0..THREADS {
let c = barrier.clone();
let buf = buf.clone();
joins.push(thread::spawn(move || {
c.wait();
let buf: Bytes = (*buf).clone();
drop(buf);
}));
}
for th in joins {
th.join().unwrap();
}
assert_eq!(*buf, data[..]);
}
}
#[test]
fn partial_eq_bytesmut() {
let bytes = Bytes::from(&b"The quick red fox"[..]);
let bytesmut = BytesMut::from(&b"The quick red fox"[..]);
assert!(bytes == bytesmut);
assert!(bytesmut == bytes);
let bytes2 = Bytes::from(&b"Jumped over the lazy brown dog"[..]);
assert!(bytes2 != bytesmut);
assert!(bytesmut != bytes2);
}