Add buffer write support
parent
8174f0cde1
commit
9373f04b48
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@ -14,6 +14,7 @@ maintenance = { status = "actively-developed" }
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[dependencies]
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aeron_driver-sys = { path = "./aeron_driver-sys" }
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memmap = "0.7"
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num = "0.2"
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[dev-dependencies]
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clap = "2.33"
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@ -26,8 +26,8 @@ impl<'a> AtomicBuffer<'a> {
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AtomicBuffer { buffer }
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}
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fn bounds_check<T>(&self, offset: IndexT) -> Result<()> {
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if offset < 0 || self.buffer.len() - (offset as usize) < size_of::<T>() {
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fn bounds_check(&self, offset: IndexT, size: IndexT) -> Result<()> {
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if offset < 0 || size < 0 || self.buffer.len() as IndexT - offset < size {
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Err(AeronError::OutOfBounds)
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} else {
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Ok(())
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@ -39,7 +39,8 @@ impl<'a> AtomicBuffer<'a> {
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where
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T: Sized,
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{
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self.bounds_check::<T>(offset).map(|_| {
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self.bounds_check(offset, size_of::<T>() as IndexT)
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.map(|_| {
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let offset_ptr = unsafe { self.buffer.as_ptr().offset(offset as isize) };
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unsafe { &*(offset_ptr as *const T) }
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})
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@ -49,7 +50,8 @@ impl<'a> AtomicBuffer<'a> {
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where
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T: Copy,
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{
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self.bounds_check::<T>(offset).map(|_| {
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self.bounds_check(offset, size_of::<T>() as IndexT)
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.map(|_| {
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let offset_ptr = unsafe { self.buffer.as_ptr().offset(offset as isize) };
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unsafe { read_volatile(offset_ptr as *const T) }
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})
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@ -59,32 +61,142 @@ impl<'a> AtomicBuffer<'a> {
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where
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T: Copy,
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{
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self.bounds_check::<T>(offset).map(|_| {
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self.bounds_check(offset, size_of::<T>() as IndexT)
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.map(|_| {
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let offset_ptr = unsafe { self.buffer.as_mut_ptr().offset(offset as isize) };
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unsafe { write_volatile(offset_ptr as *mut T, val) };
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})
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}
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/// Atomically fetch the current value at an offset, and increment by delta
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// # use aeron_rs::util::AeronError;
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/// let mut bytes = [0u8; 9];
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/// let mut buffer = AtomicBuffer::wrap(&mut bytes);
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///
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/// // Simple case modifies only the first byte
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/// assert_eq!(buffer.get_and_add_i64(0, 1), Ok(0));
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/// assert_eq!(buffer.get_and_add_i64(0, 0), Ok(1));
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///
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/// // Using an offset modifies the second byte
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/// assert_eq!(buffer.get_and_add_i64(1, 1), Ok(0));
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/// assert_eq!(buffer.get_and_add_i64(1, 0), Ok(1));
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///
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/// // An offset of 2 means buffer size must be 10 to contain an `i64`
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/// assert_eq!(buffer.get_and_add_i64(2, 0), Err(AeronError::OutOfBounds));
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/// ```
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pub fn get_and_add_i64(&self, offset: IndexT, delta: i64) -> Result<i64> {
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self.overlay::<AtomicI64>(offset)
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.map(|a| a.fetch_add(delta, Ordering::SeqCst))
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}
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/// Perform a volatile read
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// let mut bytes = [12, 0, 0, 0, 0, 0, 0, 0];
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/// let buffer = AtomicBuffer::wrap(&mut bytes);
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///
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/// assert_eq!(buffer.get_i64_volatile(0), Ok(12));
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/// ```
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pub fn get_i64_volatile(&self, offset: IndexT) -> Result<i64> {
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// QUESTION: Would it be better to express this in terms of an atomic read?
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self.overlay_volatile::<i64>(offset)
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}
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/// Perform a volatile write into the buffer
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/// Perform a volatile read
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// let mut bytes = [12, 0, 0, 0];
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/// let buffer = AtomicBuffer::wrap(&mut bytes);
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///
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/// assert_eq!(buffer.get_i32_volatile(0), Ok(12));
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/// ```
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pub fn get_i32_volatile(&self, offset: IndexT) -> Result<i32> {
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self.overlay_volatile::<i32>(offset)
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}
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/// Perform a volatile write of an `i64` into the buffer
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// let mut bytes = [0u8; 8];
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/// let mut buffer = AtomicBuffer::wrap(&mut bytes);
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///
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/// buffer.put_i64_ordered(0, 12);
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/// assert_eq!(buffer.get_i64_volatile(0), Ok(12));
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/// ```
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pub fn put_i64_ordered(&mut self, offset: IndexT, val: i64) -> Result<()> {
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// QUESTION: Would it be better to have callers use `write_volatile` directly
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self.write_volatile::<i64>(offset, val)
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}
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/// Perform a volatile write of an `i32` into the buffer
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// let mut bytes = [0u8; 4];
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/// let mut buffer = AtomicBuffer::wrap(&mut bytes);
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///
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/// buffer.put_i32_ordered(0, 12);
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/// assert_eq!(buffer.get_i32_volatile(0), Ok(12));
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/// ```
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pub fn put_i32_ordered(&mut self, offset: IndexT, val: i32) -> Result<()> {
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// QUESTION: Would it be better to have callers use `write_volatile` directly
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self.write_volatile::<i32>(offset, val)
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}
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/// Write the contents of one buffer to another. Does not perform any synchronization.
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// let mut source_bytes = [1u8, 2, 3, 4];
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/// let source = AtomicBuffer::wrap(&mut source_bytes);
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///
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/// let mut dest_bytes = [0, 0, 0, 0];
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/// let mut dest = AtomicBuffer::wrap(&mut dest_bytes);
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///
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/// dest.put_bytes(1, &source, 1, 3);
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/// drop(dest);
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/// assert_eq!(dest_bytes, [0u8, 2, 3, 4]);
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/// ```
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pub fn put_bytes(
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&mut self,
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index: IndexT,
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source: &AtomicBuffer,
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source_index: IndexT,
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len: IndexT,
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) -> Result<()> {
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self.bounds_check(index, len)?;
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source.bounds_check(source_index, len)?;
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let index = index as usize;
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let source_index = source_index as usize;
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let len = len as usize;
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self.buffer[index..index + len].copy_from_slice(&source[source_index..source_index + len]);
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Ok(())
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}
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/// Compare an expected value with what is in memory, and if it matches,
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/// update to a new value. Returns `Ok(true)` if the update was successful,
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/// and `Ok(false)` if the update failed.
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///
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/// ```rust
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/// # use aeron_rs::client::concurrent::atomic_buffer::AtomicBuffer;
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/// let mut buf = [0u8; 8];
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/// let atomic_buf = AtomicBuffer::wrap(&mut buf);
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/// // Set value to 1
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/// atomic_buf.get_and_add_i64(0, 1).unwrap();
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///
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/// // Set value to 1 if existing value is 0
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/// assert_eq!(atomic_buf.compare_and_set_i64(0, 0, 1), Ok(false));
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/// // Set value to 2 if existing value is 1
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/// assert_eq!(atomic_buf.compare_and_set_i64(0, 1, 2), Ok(true));
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/// assert_eq!(atomic_buf.get_i64_volatile(0), Ok(2));
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/// ```
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pub fn compare_and_set_i64(&self, offset: IndexT, expected: i64, update: i64) -> Result<bool> {
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// QUESTION: Do I need a volatile and atomic read here?
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// Aeron C++ uses a volatile read before the atomic operation, but I think that
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@ -126,46 +238,6 @@ mod tests {
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assert_eq!(value, (*a).load(Ordering::SeqCst));
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}
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#[test]
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fn atomic_i64_increment() {
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let mut buf = [16, 0, 0, 0, 0, 0, 0, 0];
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let atomic_buf = AtomicBuffer::wrap(&mut buf[..]);
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assert_eq!(atomic_buf.get_and_add_i64(0, 1), Ok(16));
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assert_eq!(atomic_buf.get_and_add_i64(0, 0), Ok(17));
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}
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#[test]
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fn atomic_i64_increment_offset() {
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let mut buf = [0, 16, 0, 0, 0, 0, 0, 0, 0];
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let atomic_buf = AtomicBuffer::wrap(&mut buf[..]);
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assert_eq!(atomic_buf.get_and_add_i64(1, 1), Ok(16));
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assert_eq!(atomic_buf.get_and_add_i64(1, 0), Ok(17));
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}
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#[test]
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fn out_of_bounds() {
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let mut buf = [16, 0, 0, 0, 0, 0, 0];
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let atomic_buf = AtomicBuffer::wrap(&mut buf);
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assert_eq!(
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atomic_buf.get_and_add_i64(0, 0),
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Err(AeronError::OutOfBounds)
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);
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}
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#[test]
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fn out_of_bounds_offset() {
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let mut buf = [16, 0, 0, 0, 0, 0, 0, 0];
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let atomic_buf = AtomicBuffer::wrap(&mut buf);
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assert_eq!(
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atomic_buf.get_and_add_i64(1, 0),
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Err(AeronError::OutOfBounds)
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);
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}
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#[test]
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fn negative_offset() {
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let mut buf = [16, 0, 0, 0, 0, 0, 0, 0];
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@ -175,25 +247,4 @@ mod tests {
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Err(AeronError::OutOfBounds)
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)
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}
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#[test]
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fn put_i64() {
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let mut buf = [0u8; 8];
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let mut atomic_buf = AtomicBuffer::wrap(&mut buf);
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atomic_buf.put_i64_ordered(0, 12).unwrap();
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assert_eq!(atomic_buf.get_i64_volatile(0), Ok(12))
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}
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#[test]
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fn compare_set_i64() {
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let mut buf = [0u8; 8];
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let atomic_buf = AtomicBuffer::wrap(&mut buf);
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atomic_buf.get_and_add_i64(0, 1).unwrap();
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assert_eq!(atomic_buf.compare_and_set_i64(0, 0, 1), Ok(false));
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assert_eq!(atomic_buf.compare_and_set_i64(0, 1, 2), Ok(true));
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assert_eq!(atomic_buf.get_i64_volatile(0), Ok(2));
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}
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}
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@ -1,12 +1,13 @@
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//! Ring buffer wrapper for communicating with the Media Driver
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use crate::client::concurrent::atomic_buffer::AtomicBuffer;
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use crate::util::{AeronError, IndexT, Result};
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use crate::util::{bit, AeronError, IndexT, Result};
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/// Description of the Ring Buffer schema.
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pub mod buffer_descriptor {
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use crate::client::concurrent::atomic_buffer::AtomicBuffer;
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use crate::util::bit::is_power_of_two;
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use crate::util::AeronError::IllegalArgument;
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use crate::util::{is_power_of_two, IndexT, Result, CACHE_LINE_LENGTH};
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use crate::util::{IndexT, Result, CACHE_LINE_LENGTH};
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// QUESTION: Why are these offsets so large when we only ever use i64 types?
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@ -57,12 +58,17 @@ pub mod buffer_descriptor {
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/// +---------------------------------------------------------------+
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/// ```
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pub mod record_descriptor {
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use crate::util::IndexT;
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use std::mem::size_of;
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use crate::util::Result;
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use crate::util::{AeronError, IndexT};
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/// Size of the ring buffer record header.
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pub const HEADER_LENGTH: IndexT = size_of::<i32>() as IndexT * 2;
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/// Alignment size of records written to the buffer
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pub const ALIGNMENT: IndexT = HEADER_LENGTH;
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/// Message type indicating to the media driver that space has been reserved,
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/// and is not yet ready for processing.
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pub const PADDING_MSG_TYPE_ID: i32 = -1;
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@ -73,16 +79,36 @@ pub mod record_descriptor {
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// Smells like Java.
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((i64::from(msg_type_id) & 0xFFFF_FFFF) << 32) | (i64::from(length) & 0xFFFF_FFFF)
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}
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/// Verify a message type identifier is safe for use
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pub fn check_msg_type_id(msg_type_id: i32) -> Result<()> {
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if msg_type_id < 1 {
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Err(AeronError::IllegalArgument)
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} else {
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Ok(())
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}
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}
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/// Fetch the offset to begin writing a message payload
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pub fn encoded_msg_offset(record_offset: IndexT) -> IndexT {
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record_offset + HEADER_LENGTH
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}
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/// Fetch the offset to begin writing the message length
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pub fn length_offset(record_offset: IndexT) -> IndexT {
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record_offset
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}
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}
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/// Multi-producer, single-consumer ring buffer implementation.
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pub struct ManyToOneRingBuffer<'a> {
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buffer: AtomicBuffer<'a>,
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capacity: IndexT,
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max_msg_length: IndexT,
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tail_position_index: IndexT,
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head_cache_position_index: IndexT,
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head_position_index: IndexT,
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_correlation_id_counter_index: IndexT,
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correlation_id_counter_index: IndexT,
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}
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impl<'a> ManyToOneRingBuffer<'a> {
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@ -91,17 +117,65 @@ impl<'a> ManyToOneRingBuffer<'a> {
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buffer_descriptor::check_capacity(&buffer).map(|capacity| ManyToOneRingBuffer {
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buffer,
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capacity,
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max_msg_length: capacity / 8,
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tail_position_index: capacity + buffer_descriptor::TAIL_POSITION_OFFSET,
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head_cache_position_index: capacity + buffer_descriptor::HEAD_CACHE_POSITION_OFFSET,
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head_position_index: capacity + buffer_descriptor::HEAD_POSITION_OFFSET,
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_correlation_id_counter_index: capacity + buffer_descriptor::CORRELATION_COUNTER_OFFSET,
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correlation_id_counter_index: capacity + buffer_descriptor::CORRELATION_COUNTER_OFFSET,
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})
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}
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/// Atomically retrieve the next correlation identifier. Used as a unique identifier for
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/// interactions with the Media Driver
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pub fn next_correlation_id(&self) -> i64 {
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// UNWRAP: Known-valid offset calculated during initialization
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self.buffer
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.get_and_add_i64(self.correlation_id_counter_index, 1)
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.unwrap()
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}
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/// Write a message into the ring buffer
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pub fn write(
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&mut self,
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msg_type_id: i32,
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source: &AtomicBuffer,
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source_index: IndexT,
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length: IndexT,
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) -> Result<()> {
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record_descriptor::check_msg_type_id(msg_type_id)?;
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self.check_msg_length(length)?;
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let record_len = length + record_descriptor::HEADER_LENGTH;
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let required = bit::align(record_len, record_descriptor::ALIGNMENT);
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let record_index = self.claim_capacity(required)?;
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// UNWRAP: `claim_capacity` performed bounds checking
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self.buffer
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.put_i64_ordered(
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record_index,
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record_descriptor::make_header(-length, msg_type_id),
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)
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.unwrap();
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// UNWRAP: `claim_capacity` performed bounds checking
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self.buffer
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.put_bytes(
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record_descriptor::encoded_msg_offset(record_index),
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source,
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source_index,
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length,
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)
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.unwrap();
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// UNWRAP: `claim_capacity` performed bounds checking
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self.buffer
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.put_i32_ordered(record_descriptor::length_offset(record_index), record_len)
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.unwrap();
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Ok(())
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}
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/// Claim capacity for a specific message size in the ring buffer. Returns the offset/index
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/// at which to start writing the next record.
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// TODO: Shouldn't be `pub`, just trying to avoid warnings
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pub fn claim_capacity(&mut self, required: IndexT) -> Result<IndexT> {
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fn claim_capacity(&mut self, required: IndexT) -> Result<IndexT> {
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// QUESTION: Is this mask how we handle the "ring" in ring buffer?
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// Would explain why we assert buffer capacity is a power of two during initialization
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let mask = self.capacity - 1;
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@ -199,15 +273,27 @@ impl<'a> ManyToOneRingBuffer<'a> {
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Ok(tail_index)
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}
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fn check_msg_length(&self, length: IndexT) -> Result<()> {
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if length > self.max_msg_length {
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Err(AeronError::IllegalArgument)
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} else {
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Ok(())
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}
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}
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}
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#[cfg(test)]
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mod tests {
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use crate::client::concurrent::atomic_buffer::AtomicBuffer;
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use crate::client::concurrent::ring_buffer::ManyToOneRingBuffer;
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use crate::client::concurrent::ring_buffer::{
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buffer_descriptor, record_descriptor, ManyToOneRingBuffer,
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};
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use crate::util::IndexT;
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use std::mem::size_of;
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#[test]
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fn basic_claim_space() {
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fn claim_capacity_basic() {
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let buf_size = super::buffer_descriptor::TRAILER_LENGTH as usize + 64;
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let mut buf = vec![0u8; buf_size];
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@ -225,4 +311,31 @@ mod tests {
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let write_start = ring_buf.claim_capacity(16).unwrap();
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assert_eq!(write_start, 16);
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}
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#[test]
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fn write_basic() {
|
||||
let mut bytes = vec![0u8; 512 + buffer_descriptor::TRAILER_LENGTH as usize];
|
||||
let buffer = AtomicBuffer::wrap(&mut bytes);
|
||||
let mut ring_buffer = ManyToOneRingBuffer::wrap(buffer).expect("Invalid buffer size");
|
||||
|
||||
let mut source_bytes = [12, 0, 0, 0, 0, 0, 0, 0];
|
||||
let source_len = source_bytes.len() as IndexT;
|
||||
let source_buffer = AtomicBuffer::wrap(&mut source_bytes);
|
||||
let type_id = 1;
|
||||
ring_buffer
|
||||
.write(type_id, &source_buffer, 0, source_len)
|
||||
.unwrap();
|
||||
|
||||
drop(ring_buffer);
|
||||
let buffer = AtomicBuffer::wrap(&mut bytes);
|
||||
let record_len = source_len + record_descriptor::HEADER_LENGTH;
|
||||
assert_eq!(
|
||||
buffer.get_i64_volatile(0).unwrap(),
|
||||
record_descriptor::make_header(record_len, type_id)
|
||||
);
|
||||
assert_eq!(
|
||||
buffer.get_i64_volatile(size_of::<i64>() as IndexT).unwrap(),
|
||||
12
|
||||
);
|
||||
}
|
||||
}
|
||||
|
|
39
src/util.rs
39
src/util.rs
|
@ -6,11 +6,6 @@
|
|||
// QUESTION: Can this just be updated to be `usize` in Rust?
|
||||
pub type IndexT = i32;
|
||||
|
||||
/// Helper method for quick verification that `IndexT` is a positive power of two
|
||||
pub fn is_power_of_two(idx: IndexT) -> bool {
|
||||
idx > 0 && (idx as u32).is_power_of_two()
|
||||
}
|
||||
|
||||
/// Length of the data blocks used by the CPU cache sub-system in bytes
|
||||
pub const CACHE_LINE_LENGTH: usize = 64;
|
||||
|
||||
|
@ -28,3 +23,37 @@ pub enum AeronError {
|
|||
|
||||
/// Result type for operations in the Aeron client
|
||||
pub type Result<T> = ::std::result::Result<T, AeronError>;
|
||||
|
||||
/// Bit-level utility functions
|
||||
pub mod bit {
|
||||
use crate::util::IndexT;
|
||||
use num::PrimInt;
|
||||
|
||||
/// Helper method for quick verification that `IndexT` is a positive power of two
|
||||
///
|
||||
/// ```rust
|
||||
/// # use aeron_rs::util::bit::is_power_of_two;
|
||||
/// assert!(is_power_of_two(16));
|
||||
/// assert!(!is_power_of_two(17));
|
||||
/// ```
|
||||
pub fn is_power_of_two(idx: IndexT) -> bool {
|
||||
idx > 0 && (idx as u32).is_power_of_two()
|
||||
}
|
||||
|
||||
/// Align a specific value to the next largest alignment size.
|
||||
///
|
||||
/// ```rust
|
||||
/// # use aeron_rs::util::bit::align;
|
||||
/// assert_eq!(align(7, 8), 8);
|
||||
///
|
||||
/// // Not intended for alignments that aren't powers of two
|
||||
/// assert_eq!(align(52, 12), 52);
|
||||
/// assert_eq!(align(52, 16), 64);
|
||||
/// ```
|
||||
pub fn align<T>(val: T, alignment: T) -> T
|
||||
where
|
||||
T: PrimInt,
|
||||
{
|
||||
(val + (alignment - T::one())) & !(alignment - T::one())
|
||||
}
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue