feat: add search filter, refactor params

src/util/protobuf.rs

@@ -0,0 +1,56 @@
+/// [`ProtoBuilder`] is used to construct protobuf messages using a builder pattern
+#[derive(Debug, Default)]
+pub struct ProtoBuilder {
+    pub bytes: Vec<u8>,
+}
+
+impl ProtoBuilder {
+    /// Instantiate a new [`ProtoBuilder`]
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Internal: write a raw varint value
+    fn _varint(&mut self, val: u64) {
+        if val == 0 {
+            self.bytes.push(0);
+        } else {
+            let mut v = val;
+            while v != 0 {
+                let mut byte = (v & 0x7f) as u8;
+                v >>= 7;
+
+                if v != 0 {
+                    byte |= 0x80;
+                }
+
+                self.bytes.push(byte);
+            }
+        }
+    }
+
+    /// Internal: write a field tag
+    ///
+    /// Reference: <https://developers.google.com/protocol-buffers/docs/encoding?hl=en#structure>
+    fn _field(&mut self, field: u32, wire: u8) {
+        let fbits: u64 = (field as u64) << 3;
+        let wbits = wire as u64 & 0x07;
+        let val: u64 = fbits | wbits;
+        self._varint(val);
+    }
+
+    /// Write a varint field
+    pub fn varint(&mut self, field: u32, val: u64) {
+        self._field(field, 0);
+        self._varint(val);
+    }
+
+    /// Write an embedded message
+    ///
+    /// Requires passing another [`ProtoBuilder`] with the embedded message.
+    pub fn embedded(&mut self, field: u32, mut pb: Self) {
+        self._field(field, 2);
+        self._varint(pb.bytes.len() as u64);
+        self.bytes.append(&mut pb.bytes);
+    }
+}