1 files changed, 75 insertions, 0 deletions

diff --git a/crates/profile/src/memory_usage.rs b/crates/profile/src/memory_usage.rs
new file mode 100644
index 000000000..83390212a
--- /dev/null
+++ b/crates/profile/src/memory_usage.rs
@@ -0,0 +1,75 @@
+//! FIXME: write short doc here
+use std::fmt;
+
+use cfg_if::cfg_if;
+
+#[derive(Copy, Clone)]
+pub struct MemoryUsage {
+    pub allocated: Bytes,
+}
+
+impl fmt::Display for MemoryUsage {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{}", self.allocated)
+    }
+}
+
+impl std::ops::Sub for MemoryUsage {
+    type Output = MemoryUsage;
+    fn sub(self, rhs: MemoryUsage) -> MemoryUsage {
+        MemoryUsage { allocated: self.allocated - rhs.allocated }
+    }
+}
+
+impl MemoryUsage {
+    pub fn current() -> MemoryUsage {
+        cfg_if! {
+            if #[cfg(all(target_os = "linux", target_env = "gnu"))] {
+                // Note: This is incredibly slow.
+                let alloc = unsafe { libc::mallinfo() }.uordblks as isize;
+                MemoryUsage { allocated: Bytes(alloc) }
+            } else {
+                MemoryUsage { allocated: Bytes(0) }
+            }
+        }
+    }
+}
+
+#[derive(Default, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
+pub struct Bytes(isize);
+
+impl Bytes {
+    pub fn megabytes(self) -> isize {
+        self.0 / 1024 / 1024
+    }
+}
+
+impl fmt::Display for Bytes {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let bytes = self.0;
+        let mut value = bytes;
+        let mut suffix = "b";
+        if value.abs() > 4096 {
+            value /= 1024;
+            suffix = "kb";
+            if value.abs() > 4096 {
+                value /= 1024;
+                suffix = "mb";
+            }
+        }
+        f.pad(&format!("{}{}", value, suffix))
+    }
+}
+
+impl std::ops::AddAssign<usize> for Bytes {
+    fn add_assign(&mut self, x: usize) {
+        self.0 += x as isize;
+    }
+}
+
+impl std::ops::Sub for Bytes {
+    type Output = Bytes;
+    fn sub(self, rhs: Bytes) -> Bytes {
+        Bytes(self.0 - rhs.0)
+    }
+}