1 files changed, 88 insertions, 0 deletions
diff --git a/src/parser.rs b/src/parser.rs
new file mode 100644
index 0000000..89c88ab
--- /dev/null
+++ b/src/parser.rs
@@ -0,0 +1,88 @@
+#[repr(packed)]
+struct Header {
+    secs: u32,
+    micros: u32,
+    len: u32,
+}
+
+impl Header {
+    fn time(&self) -> std::time::Duration {
+        std::time::Duration::from_micros(u64::from(
+            self.secs * 1_000_000 + self.micros,
+        ))
+    }
+
+    fn len(&self) -> usize {
+        self.len as usize
+    }
+}
+
+pub struct Parser {
+    reading: std::collections::VecDeque<u8>,
+    read_state: Option<Header>,
+}
+
+impl Parser {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    pub fn add_bytes(&mut self, bytes: &[u8]) {
+        self.reading.extend(bytes.iter());
+    }
+
+    pub fn next_frame(&mut self) -> Option<crate::frame::Frame> {
+        let header = if let Some(header) = &self.read_state {
+            header
+        } else {
+            if self.reading.len() < std::mem::size_of::<Header>() {
+                return None;
+            }
+
+            let secs1 = self.reading.pop_front().unwrap();
+            let secs2 = self.reading.pop_front().unwrap();
+            let secs3 = self.reading.pop_front().unwrap();
+            let secs4 = self.reading.pop_front().unwrap();
+            let secs = u32::from_le_bytes([secs1, secs2, secs3, secs4]);
+
+            let usecs1 = self.reading.pop_front().unwrap();
+            let usecs2 = self.reading.pop_front().unwrap();
+            let usecs3 = self.reading.pop_front().unwrap();
+            let usecs4 = self.reading.pop_front().unwrap();
+            let micros = u32::from_le_bytes([usecs1, usecs2, usecs3, usecs4]);
+
+            let len1 = self.reading.pop_front().unwrap();
+            let len2 = self.reading.pop_front().unwrap();
+            let len3 = self.reading.pop_front().unwrap();
+            let len4 = self.reading.pop_front().unwrap();
+            let len = u32::from_le_bytes([len1, len2, len3, len4]);
+
+            let header = Header { secs, micros, len };
+            self.read_state = Some(header);
+            self.read_state.as_ref().unwrap()
+        };
+
+        if self.reading.len() < header.len() {
+            return None;
+        }
+
+        let mut data = vec![];
+        for _ in 0..header.len() {
+            data.push(self.reading.pop_front().unwrap());
+        }
+
+        let time = header.time();
+
+        self.read_state = None;
+        Some(crate::frame::Frame { time, data })
+    }
+}
+
+impl Default for Parser {
+    fn default() -> Self {
+        Self {
+            reading: std::collections::VecDeque::new(),
+            read_state: None,
+        }
+    }
+}