diff options
Diffstat (limited to 'library/std/src/io/tests.rs')
| -rw-r--r-- | library/std/src/io/tests.rs | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/library/std/src/io/tests.rs b/library/std/src/io/tests.rs new file mode 100644 index 00000000000..913b28538b7 --- /dev/null +++ b/library/std/src/io/tests.rs @@ -0,0 +1,494 @@ +use super::{repeat, Cursor, SeekFrom}; +use crate::cmp::{self, min}; +use crate::io::prelude::*; +use crate::io::{self, IoSlice, IoSliceMut}; +use crate::ops::Deref; + +#[test] +#[cfg_attr(target_os = "emscripten", ignore)] +fn read_until() { + let mut buf = Cursor::new(&b"12"[..]); + let mut v = Vec::new(); + assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 2); + assert_eq!(v, b"12"); + + let mut buf = Cursor::new(&b"1233"[..]); + let mut v = Vec::new(); + assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 3); + assert_eq!(v, b"123"); + v.truncate(0); + assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 1); + assert_eq!(v, b"3"); + v.truncate(0); + assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 0); + assert_eq!(v, []); +} + +#[test] +fn split() { + let buf = Cursor::new(&b"12"[..]); + let mut s = buf.split(b'3'); + assert_eq!(s.next().unwrap().unwrap(), vec![b'1', b'2']); + assert!(s.next().is_none()); + + let buf = Cursor::new(&b"1233"[..]); + let mut s = buf.split(b'3'); + assert_eq!(s.next().unwrap().unwrap(), vec![b'1', b'2']); + assert_eq!(s.next().unwrap().unwrap(), vec![]); + assert!(s.next().is_none()); +} + +#[test] +fn read_line() { + let mut buf = Cursor::new(&b"12"[..]); + let mut v = String::new(); + assert_eq!(buf.read_line(&mut v).unwrap(), 2); + assert_eq!(v, "12"); + + let mut buf = Cursor::new(&b"12\n\n"[..]); + let mut v = String::new(); + assert_eq!(buf.read_line(&mut v).unwrap(), 3); + assert_eq!(v, "12\n"); + v.truncate(0); + assert_eq!(buf.read_line(&mut v).unwrap(), 1); + assert_eq!(v, "\n"); + v.truncate(0); + assert_eq!(buf.read_line(&mut v).unwrap(), 0); + assert_eq!(v, ""); +} + +#[test] +fn lines() { + let buf = Cursor::new(&b"12\r"[..]); + let mut s = buf.lines(); + assert_eq!(s.next().unwrap().unwrap(), "12\r".to_string()); + assert!(s.next().is_none()); + + let buf = Cursor::new(&b"12\r\n\n"[..]); + let mut s = buf.lines(); + assert_eq!(s.next().unwrap().unwrap(), "12".to_string()); + assert_eq!(s.next().unwrap().unwrap(), "".to_string()); + assert!(s.next().is_none()); +} + +#[test] +fn read_to_end() { + let mut c = Cursor::new(&b""[..]); + let mut v = Vec::new(); + assert_eq!(c.read_to_end(&mut v).unwrap(), 0); + assert_eq!(v, []); + + let mut c = Cursor::new(&b"1"[..]); + let mut v = Vec::new(); + assert_eq!(c.read_to_end(&mut v).unwrap(), 1); + assert_eq!(v, b"1"); + + let cap = 1024 * 1024; + let data = (0..cap).map(|i| (i / 3) as u8).collect::<Vec<_>>(); + let mut v = Vec::new(); + let (a, b) = data.split_at(data.len() / 2); + assert_eq!(Cursor::new(a).read_to_end(&mut v).unwrap(), a.len()); + assert_eq!(Cursor::new(b).read_to_end(&mut v).unwrap(), b.len()); + assert_eq!(v, data); +} + +#[test] +fn read_to_string() { + let mut c = Cursor::new(&b""[..]); + let mut v = String::new(); + assert_eq!(c.read_to_string(&mut v).unwrap(), 0); + assert_eq!(v, ""); + + let mut c = Cursor::new(&b"1"[..]); + let mut v = String::new(); + assert_eq!(c.read_to_string(&mut v).unwrap(), 1); + assert_eq!(v, "1"); + + let mut c = Cursor::new(&b"\xff"[..]); + let mut v = String::new(); + assert!(c.read_to_string(&mut v).is_err()); +} + +#[test] +fn read_exact() { + let mut buf = [0; 4]; + + let mut c = Cursor::new(&b""[..]); + assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); + + let mut c = Cursor::new(&b"123"[..]).chain(Cursor::new(&b"456789"[..])); + c.read_exact(&mut buf).unwrap(); + assert_eq!(&buf, b"1234"); + c.read_exact(&mut buf).unwrap(); + assert_eq!(&buf, b"5678"); + assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); +} + +#[test] +fn read_exact_slice() { + let mut buf = [0; 4]; + + let mut c = &b""[..]; + assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); + + let mut c = &b"123"[..]; + assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); + // make sure the optimized (early returning) method is being used + assert_eq!(&buf, &[0; 4]); + + let mut c = &b"1234"[..]; + c.read_exact(&mut buf).unwrap(); + assert_eq!(&buf, b"1234"); + + let mut c = &b"56789"[..]; + c.read_exact(&mut buf).unwrap(); + assert_eq!(&buf, b"5678"); + assert_eq!(c, b"9"); +} + +#[test] +fn take_eof() { + struct R; + + impl Read for R { + fn read(&mut self, _: &mut [u8]) -> io::Result<usize> { + Err(io::Error::new(io::ErrorKind::Other, "")) + } + } + impl BufRead for R { + fn fill_buf(&mut self) -> io::Result<&[u8]> { + Err(io::Error::new(io::ErrorKind::Other, "")) + } + fn consume(&mut self, _amt: usize) {} + } + + let mut buf = [0; 1]; + assert_eq!(0, R.take(0).read(&mut buf).unwrap()); + assert_eq!(b"", R.take(0).fill_buf().unwrap()); +} + +fn cmp_bufread<Br1: BufRead, Br2: BufRead>(mut br1: Br1, mut br2: Br2, exp: &[u8]) { + let mut cat = Vec::new(); + loop { + let consume = { + let buf1 = br1.fill_buf().unwrap(); + let buf2 = br2.fill_buf().unwrap(); + let minlen = if buf1.len() < buf2.len() { buf1.len() } else { buf2.len() }; + assert_eq!(buf1[..minlen], buf2[..minlen]); + cat.extend_from_slice(&buf1[..minlen]); + minlen + }; + if consume == 0 { + break; + } + br1.consume(consume); + br2.consume(consume); + } + assert_eq!(br1.fill_buf().unwrap().len(), 0); + assert_eq!(br2.fill_buf().unwrap().len(), 0); + assert_eq!(&cat[..], &exp[..]) +} + +#[test] +fn chain_bufread() { + let testdata = b"ABCDEFGHIJKL"; + let chain1 = + (&testdata[..3]).chain(&testdata[3..6]).chain(&testdata[6..9]).chain(&testdata[9..]); + let chain2 = (&testdata[..4]).chain(&testdata[4..8]).chain(&testdata[8..]); + cmp_bufread(chain1, chain2, &testdata[..]); +} + +#[test] +fn chain_zero_length_read_is_not_eof() { + let a = b"A"; + let b = b"B"; + let mut s = String::new(); + let mut chain = (&a[..]).chain(&b[..]); + chain.read(&mut []).unwrap(); + chain.read_to_string(&mut s).unwrap(); + assert_eq!("AB", s); +} + +#[bench] +#[cfg_attr(target_os = "emscripten", ignore)] +fn bench_read_to_end(b: &mut test::Bencher) { + b.iter(|| { + let mut lr = repeat(1).take(10000000); + let mut vec = Vec::with_capacity(1024); + super::read_to_end(&mut lr, &mut vec) + }); +} + +#[test] +fn seek_len() -> io::Result<()> { + let mut c = Cursor::new(vec![0; 15]); + assert_eq!(c.stream_len()?, 15); + + c.seek(SeekFrom::End(0))?; + let old_pos = c.stream_position()?; + assert_eq!(c.stream_len()?, 15); + assert_eq!(c.stream_position()?, old_pos); + + c.seek(SeekFrom::Start(7))?; + c.seek(SeekFrom::Current(2))?; + let old_pos = c.stream_position()?; + assert_eq!(c.stream_len()?, 15); + assert_eq!(c.stream_position()?, old_pos); + + Ok(()) +} + +#[test] +fn seek_position() -> io::Result<()> { + // All `asserts` are duplicated here to make sure the method does not + // change anything about the seek state. + let mut c = Cursor::new(vec![0; 15]); + assert_eq!(c.stream_position()?, 0); + assert_eq!(c.stream_position()?, 0); + + c.seek(SeekFrom::End(0))?; + assert_eq!(c.stream_position()?, 15); + assert_eq!(c.stream_position()?, 15); + + c.seek(SeekFrom::Start(7))?; + c.seek(SeekFrom::Current(2))?; + assert_eq!(c.stream_position()?, 9); + assert_eq!(c.stream_position()?, 9); + + c.seek(SeekFrom::End(-3))?; + c.seek(SeekFrom::Current(1))?; + c.seek(SeekFrom::Current(-5))?; + assert_eq!(c.stream_position()?, 8); + assert_eq!(c.stream_position()?, 8); + + Ok(()) +} + +// A simple example reader which uses the default implementation of +// read_to_end. +struct ExampleSliceReader<'a> { + slice: &'a [u8], +} + +impl<'a> Read for ExampleSliceReader<'a> { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + let len = cmp::min(self.slice.len(), buf.len()); + buf[..len].copy_from_slice(&self.slice[..len]); + self.slice = &self.slice[len..]; + Ok(len) + } +} + +#[test] +fn test_read_to_end_capacity() -> io::Result<()> { + let input = &b"foo"[..]; + + // read_to_end() generally needs to over-allocate, both for efficiency + // and so that it can distinguish EOF. Assert that this is the case + // with this simple ExampleSliceReader struct, which uses the default + // implementation of read_to_end. Even though vec1 is allocated with + // exactly enough capacity for the read, read_to_end will allocate more + // space here. + let mut vec1 = Vec::with_capacity(input.len()); + ExampleSliceReader { slice: input }.read_to_end(&mut vec1)?; + assert_eq!(vec1.len(), input.len()); + assert!(vec1.capacity() > input.len(), "allocated more"); + + // However, std::io::Take includes an implementation of read_to_end + // that will not allocate when the limit has already been reached. In + // this case, vec2 never grows. + let mut vec2 = Vec::with_capacity(input.len()); + ExampleSliceReader { slice: input }.take(input.len() as u64).read_to_end(&mut vec2)?; + assert_eq!(vec2.len(), input.len()); + assert_eq!(vec2.capacity(), input.len(), "did not allocate more"); + + Ok(()) +} + +#[test] +fn io_slice_mut_advance() { + let mut buf1 = [1; 8]; + let mut buf2 = [2; 16]; + let mut buf3 = [3; 8]; + let mut bufs = &mut [ + IoSliceMut::new(&mut buf1), + IoSliceMut::new(&mut buf2), + IoSliceMut::new(&mut buf3), + ][..]; + + // Only in a single buffer.. + bufs = IoSliceMut::advance(bufs, 1); + assert_eq!(bufs[0].deref(), [1; 7].as_ref()); + assert_eq!(bufs[1].deref(), [2; 16].as_ref()); + assert_eq!(bufs[2].deref(), [3; 8].as_ref()); + + // Removing a buffer, leaving others as is. + bufs = IoSliceMut::advance(bufs, 7); + assert_eq!(bufs[0].deref(), [2; 16].as_ref()); + assert_eq!(bufs[1].deref(), [3; 8].as_ref()); + + // Removing a buffer and removing from the next buffer. + bufs = IoSliceMut::advance(bufs, 18); + assert_eq!(bufs[0].deref(), [3; 6].as_ref()); +} + +#[test] +fn io_slice_mut_advance_empty_slice() { + let empty_bufs = &mut [][..]; + // Shouldn't panic. + IoSliceMut::advance(empty_bufs, 1); +} + +#[test] +fn io_slice_mut_advance_beyond_total_length() { + let mut buf1 = [1; 8]; + let mut bufs = &mut [IoSliceMut::new(&mut buf1)][..]; + + // Going beyond the total length should be ok. + bufs = IoSliceMut::advance(bufs, 9); + assert!(bufs.is_empty()); +} + +#[test] +fn io_slice_advance() { + let buf1 = [1; 8]; + let buf2 = [2; 16]; + let buf3 = [3; 8]; + let mut bufs = &mut [IoSlice::new(&buf1), IoSlice::new(&buf2), IoSlice::new(&buf3)][..]; + + // Only in a single buffer.. + bufs = IoSlice::advance(bufs, 1); + assert_eq!(bufs[0].deref(), [1; 7].as_ref()); + assert_eq!(bufs[1].deref(), [2; 16].as_ref()); + assert_eq!(bufs[2].deref(), [3; 8].as_ref()); + + // Removing a buffer, leaving others as is. + bufs = IoSlice::advance(bufs, 7); + assert_eq!(bufs[0].deref(), [2; 16].as_ref()); + assert_eq!(bufs[1].deref(), [3; 8].as_ref()); + + // Removing a buffer and removing from the next buffer. + bufs = IoSlice::advance(bufs, 18); + assert_eq!(bufs[0].deref(), [3; 6].as_ref()); +} + +#[test] +fn io_slice_advance_empty_slice() { + let empty_bufs = &mut [][..]; + // Shouldn't panic. + IoSlice::advance(empty_bufs, 1); +} + +#[test] +fn io_slice_advance_beyond_total_length() { + let buf1 = [1; 8]; + let mut bufs = &mut [IoSlice::new(&buf1)][..]; + + // Going beyond the total length should be ok. + bufs = IoSlice::advance(bufs, 9); + assert!(bufs.is_empty()); +} + +/// Create a new writer that reads from at most `n_bufs` and reads +/// `per_call` bytes (in total) per call to write. +fn test_writer(n_bufs: usize, per_call: usize) -> TestWriter { + TestWriter { n_bufs, per_call, written: Vec::new() } +} + +struct TestWriter { + n_bufs: usize, + per_call: usize, + written: Vec<u8>, +} + +impl Write for TestWriter { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.write_vectored(&[IoSlice::new(buf)]) + } + + fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + let mut left = self.per_call; + let mut written = 0; + for buf in bufs.iter().take(self.n_bufs) { + let n = min(left, buf.len()); + self.written.extend_from_slice(&buf[0..n]); + left -= n; + written += n; + } + Ok(written) + } + + fn flush(&mut self) -> io::Result<()> { + Ok(()) + } +} + +#[test] +fn test_writer_read_from_one_buf() { + let mut writer = test_writer(1, 2); + + assert_eq!(writer.write(&[]).unwrap(), 0); + assert_eq!(writer.write_vectored(&[]).unwrap(), 0); + + // Read at most 2 bytes. + assert_eq!(writer.write(&[1, 1, 1]).unwrap(), 2); + let bufs = &[IoSlice::new(&[2, 2, 2])]; + assert_eq!(writer.write_vectored(bufs).unwrap(), 2); + + // Only read from first buf. + let bufs = &[IoSlice::new(&[3]), IoSlice::new(&[4, 4])]; + assert_eq!(writer.write_vectored(bufs).unwrap(), 1); + + assert_eq!(writer.written, &[1, 1, 2, 2, 3]); +} + +#[test] +fn test_writer_read_from_multiple_bufs() { + let mut writer = test_writer(3, 3); + + // Read at most 3 bytes from two buffers. + let bufs = &[IoSlice::new(&[1]), IoSlice::new(&[2, 2, 2])]; + assert_eq!(writer.write_vectored(bufs).unwrap(), 3); + + // Read at most 3 bytes from three buffers. + let bufs = &[IoSlice::new(&[3]), IoSlice::new(&[4]), IoSlice::new(&[5, 5])]; + assert_eq!(writer.write_vectored(bufs).unwrap(), 3); + + assert_eq!(writer.written, &[1, 2, 2, 3, 4, 5]); +} + +#[test] +fn test_write_all_vectored() { + #[rustfmt::skip] // Becomes unreadable otherwise. + let tests: Vec<(_, &'static [u8])> = vec![ + (vec![], &[]), + (vec![IoSlice::new(&[]), IoSlice::new(&[])], &[]), + (vec![IoSlice::new(&[1])], &[1]), + (vec![IoSlice::new(&[1, 2])], &[1, 2]), + (vec![IoSlice::new(&[1, 2, 3])], &[1, 2, 3]), + (vec![IoSlice::new(&[1, 2, 3, 4])], &[1, 2, 3, 4]), + (vec![IoSlice::new(&[1, 2, 3, 4, 5])], &[1, 2, 3, 4, 5]), + (vec![IoSlice::new(&[1]), IoSlice::new(&[2])], &[1, 2]), + (vec![IoSlice::new(&[1]), IoSlice::new(&[2, 2])], &[1, 2, 2]), + (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2])], &[1, 1, 2, 2]), + (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2, 2])], &[1, 1, 2, 2, 2]), + (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2, 2])], &[1, 1, 2, 2, 2]), + (vec![IoSlice::new(&[1, 1, 1]), IoSlice::new(&[2, 2, 2])], &[1, 1, 1, 2, 2, 2]), + (vec![IoSlice::new(&[1, 1, 1]), IoSlice::new(&[2, 2, 2, 2])], &[1, 1, 1, 2, 2, 2, 2]), + (vec![IoSlice::new(&[1, 1, 1, 1]), IoSlice::new(&[2, 2, 2, 2])], &[1, 1, 1, 1, 2, 2, 2, 2]), + (vec![IoSlice::new(&[1]), IoSlice::new(&[2]), IoSlice::new(&[3])], &[1, 2, 3]), + (vec![IoSlice::new(&[1, 1]), IoSlice::new(&[2, 2]), IoSlice::new(&[3, 3])], &[1, 1, 2, 2, 3, 3]), + (vec![IoSlice::new(&[1]), IoSlice::new(&[2, 2]), IoSlice::new(&[3, 3, 3])], &[1, 2, 2, 3, 3, 3]), + (vec![IoSlice::new(&[1, 1, 1]), IoSlice::new(&[2, 2, 2]), IoSlice::new(&[3, 3, 3])], &[1, 1, 1, 2, 2, 2, 3, 3, 3]), + ]; + + let writer_configs = &[(1, 1), (1, 2), (1, 3), (2, 2), (2, 3), (3, 3)]; + + for (n_bufs, per_call) in writer_configs.iter().copied() { + for (mut input, wanted) in tests.clone().into_iter() { + let mut writer = test_writer(n_bufs, per_call); + assert!(writer.write_all_vectored(&mut *input).is_ok()); + assert_eq!(&*writer.written, &*wanted); + } + } +} |